From mallain at purdue.edu Thu Nov 1 15:35:40 2012 From: mallain at purdue.edu (Allain, Monica M.C.) Date: Thu, 1 Nov 2012 19:35:40 +0000 Subject: [labnetwork] SMC--Needs a partner to decomtaminate gate and Angle valves. A 20~35 nanometer partical Counter is also needed! See details in the email Message-ID: <47D9CF1BD7125B40BD896F5FA32D88F4071D994C@WPVEXCMBX02.purdue.lcl> Dear Colleagues, SMC is looking for a partner to assist in the decontamination of Gate & Angle Valves and a 20~35 nanometer particle counter (See information below). If you provide this service in your facility or can help SMC identify a company to work with, please contact Garrett Flora: Garrett S. Flora High Vacuum Engineer 317.688.0608 or ext. 11608 gflora at smcusa.com SMC Corporation of America SMC has a need for valve decontamination, and our facility is not set up for this process. Maybe you have some suggestions for partnering with a company to infrequently decontaminate warranty returns, repairs, etc.... This is basic sample of decontamination sheet that would be signed off by cleaning company declaring a valve is safe for repairs. Normally each company develops its own unique document, procedure, template. 1. Decontamination of Gate & Angle valves [cid:_1_0A5BB2400B8D4204005734D085257AA9] [cid:_1_0A5BB4440B8D4204005734D085257AA9] Gate /Slit valve pic. Angle valve pic. Garrett S. Flora High Vacuum Engineer 317.688.0608 or ext. 11608 gflora at smcusa.com SMC Corporation of America 2. Particle counter Testing fixture to place our valves within a chamber and test for particles generated. Laser particle counter with range that can detect in the 20~35 nanometer's Thank you for your time and consideration of SMC's needs. ~ Monica M. Cortez Allain, Ph.D. ~ ************************************************************ Monica M. Cortez Allain, Ph.D. Managing Director Birck Nanotechnology Center 1205 W. State Street West Lafayette, IN 47907-2057 Phone: (765) 494-5138 Fax: (765) 496-8299 ************************************************************ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.gif Type: image/gif Size: 15832 bytes Desc: image001.gif URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.gif Type: image/gif Size: 10519 bytes Desc: image002.gif URL: From john.nibarger at nist.gov Fri Nov 2 08:41:33 2012 From: john.nibarger at nist.gov (Nibarger, John) Date: Fri, 2 Nov 2012 08:41:33 -0400 Subject: [labnetwork] special wafers In-Reply-To: Message-ID: Matthieu, We've done work on 100mm silicon wafers up to 4mm thick and have purchased them from www.el-cat.com. They have a variety of wafer substrates and an online inventory. Looking now (at http://www.el-cat.com/silicon-wafers.htm) they have DSP 150mm wafers 1mm and 1.35mm thick. Cheers, John John P. Nibarger, Ph.D. Manager, Boulder Micro-Fabrication Facility National Institute of Standards and Technology 325 Broadway, MS 817.03 Boulder, CO 80305 303-497-4575 (phone) 303-497-3042 (fax) john.nibarger at nist.gov On 10/26/12 5:55 AM, "Matthieu Nannini, Dr." wrote: >Dear colleagues, > >I'm looking for specific kinds of wafers: 150mm DSP Si 1.2mm thick. I >already tried a few suppliers (Addison, WRS and University Wafers) but >all have lead time of 8 weeks or so. >Would any of you know suppliers that could have this kind of wafers ? > >Thanks > > >----------------------------------- >Matthieu Nannini >McGill Nanotools Microfab >Manager >t: 514 398 3310 >c: 514 758 3311 >f: 514 398 8434 >http://mnm.physics.mcgill.ca/ >------------------------------------ > > >_______________________________________________ >labnetwork mailing list >labnetwork at mtl.mit.edu >https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork From codreanu at UDel.Edu Mon Nov 5 11:32:49 2012 From: codreanu at UDel.Edu (Iulian Codreanu) Date: Mon, 05 Nov 2012 11:32:49 -0500 Subject: [labnetwork] gas room means of egress Message-ID: <5097EA31.60406@udel.edu> Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware From hathaway at cns.fas.harvard.edu Mon Nov 5 15:48:46 2012 From: hathaway at cns.fas.harvard.edu (Mac Hathaway) Date: Mon, 5 Nov 2012 15:48:46 -0500 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: <5098262E.5040401@cns.fas.harvard.edu> Hi Iulian, Not much help here, I'm afraid... We only have one door in our gas bunker. However, all the cabinets are at one end, away from the door. Also, there is very heavy ventilation air-flow from the door end to room exhaust vents near the cabinets. This may have been a deliberate part of the room design, but it was before my time. Mac Hathaway Harvard CNS On 11/5/2012 11:32 AM, Iulian Codreanu wrote: > Dear Colleagues, > > I am trying to influence a decision on a second means of egress from the > gas room at the University of Delaware and your input is very much > appreciated. > > This is the room where the cabinets for toxic, flammable, and pyrophoric > as well as some panels for inert gases will be located. The room is > adjacent to and separated from the cleanroom by a fire rated wall (I was > told it is at least two hours-rated). The code consultant states that a > second means of egress is not needed for this H2 occupancy room but I > feel it is a must. > > How many doors does your gas room have? > > Thank you very much. > > Iulian From jrweaver at purdue.edu Mon Nov 5 16:21:03 2012 From: jrweaver at purdue.edu (Weaver, John R) Date: Mon, 5 Nov 2012 21:21:03 +0000 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: <6A848421F695C54A9210C1A873C96AC2068D1EEB@WPVEXCMBX04.purdue.lcl> Always two! If you have a person working in the room and the incident happens between the person and the only exit, he/she is toast! I have doors at each end of my room so that no matter where the incident would occur there is a clear exit path from the room. John R. Weaver Facility Manager Birck Nanotechnology Center Purdue University (765) 494-5494 jrweaver at purdue.edu -----Original Message----- From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu Sent: Monday, November 05, 2012 11:33 AM To: Fab Network Subject: [labnetwork] gas room means of egress Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork From lej at danchip.dtu.dk Mon Nov 5 16:29:13 2012 From: lej at danchip.dtu.dk (Leif Johansen) Date: Mon, 5 Nov 2012 22:29:13 +0100 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: <39838FA4BF2F9A43AE3918CAD0F6AF1718684B290B@WINEXCHANGE3.win.dtu.dk> Hello Iulian, Here at DTU Danchip in Denmark we have a gas bunker which also located next to the cleanroom, but separated from this by quite a thick concrete wall. We have four rooms: * One open yard with N2 tank, vaporiser, and O2 batteries. * One closed room with N2 and O2 purifiers plus N2 and He gas bottles. Accessible through only one door from the street. * One closed room with corrosive gasses (Cl2, NH3 etc.). Accessible through only one door from the street. * One closed room with flammable/pyrophoric gasses (H2, SiH4, B2H6, Cl2SiH2, etc.). Accessible through only one door from the street. Hope this information could be of some help. I you wish, I could send you some pictures. Best regards, Leif -----Original Message----- From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu Sent: Monday, November 05, 2012 5:33 PM To: Fab Network Subject: [labnetwork] gas room means of egress Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork From schweig at umich.edu Mon Nov 5 19:48:05 2012 From: schweig at umich.edu (Dennis Schweiger) Date: Mon, 5 Nov 2012 19:48:05 -0500 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: Iulian, we have a single egress door from our flammable gas storage room, but there are two doors from our toxic gas room. One to the outside of the building, and one to the inside. Their proximity to each other (about 2 feet) though doesn't really meet with the egress layout you had in mind though. I'm guessing you're thinking about opposite ends of the storage locations. Dennis 734.647.2055 Ofc On Mon, Nov 5, 2012 at 11:32 AM, Iulian Codreanu wrote: > Dear Colleagues, > > I am trying to influence a decision on a second means of egress from the > gas room at the University of Delaware and your input is very much > appreciated. > > This is the room where the cabinets for toxic, flammable, and pyrophoric > as well as some panels for inert gases will be located. The room is > adjacent to and separated from the cleanroom by a fire rated wall (I was > told it is at least two hours-rated). The code consultant states that a > second means of egress is not needed for this H2 occupancy room but I feel > it is a must. > > How many doors does your gas room have? > > Thank you very much. > > Iulian > -- > iulian Codreanu, Ph.D. > Director of Operations, UD Nanofab > University of Delaware > > ______________________________**_________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/**mailman/listinfo.cgi/**labnetwork > -------------- next part -------------- An HTML attachment was scrubbed... URL: From rmorrison at draper.com Tue Nov 6 06:18:41 2012 From: rmorrison at draper.com (Morrison, Richard H., Jr.) Date: Tue, 06 Nov 2012 11:18:41 +0000 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: Hi, AT Draper our gas room as 3 doors. One main locked to get in and 2 more emergency doors. Rick Draper Laboratory Group Leader Microfabrication Operations 555 Technology Square Cambridge Ma, 02139-3563 www.draper.com rmorrison at draper.com W 617-258-3420 C 508-930-3461 -----Original Message----- From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu Sent: Monday, November 05, 2012 11:33 AM To: Fab Network Subject: [labnetwork] gas room means of egress Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork From dabunzow at lbl.gov Tue Nov 6 09:57:58 2012 From: dabunzow at lbl.gov (David A. Bunzow) Date: Tue, 06 Nov 2012 06:57:58 -0800 Subject: [labnetwork] gas room means of egress In-Reply-To: <6A848421F695C54A9210C1A873C96AC2068D1EEB@WPVEXCMBX04.purdue.lcl> References: <5097EA31.60406@udel.edu> <6A848421F695C54A9210C1A873C96AC2068D1EEB@WPVEXCMBX04.purdue.lcl> Message-ID: <50992576.4020405@lbl.gov> DITTO...ALWAYS 2...have your code consultant think life safety, not cost of dying. While code may not require it (and I didn't see which code and interpretation was being referenced), codes are merely the MINIMUM needed, not what you would want for yourself or your people. The gas room in TMF's nanofabrication facility has 2 egress doors, one at each end.../DAB David A. Bunzow User Facilities Program Manager The Molecular Foundry Materials Science Division Lawrence Berkeley National Laboratory 1 Cyclotron Road MS 67-3207 Berkeley, CA 94720 Office: 510-486-4574 FAX: 510-486-7424 Cell: 510-542-1747 On 11/5/2012 1:21 PM, Weaver, John R wrote: > Always two! If you have a person working in the room and the incident happens between the person and the only exit, he/she is toast! I have doors at each end of my room so that no matter where the incident would occur there is a clear exit path from the room. > > John R. Weaver > Facility Manager > Birck Nanotechnology Center > Purdue University > (765) 494-5494 > jrweaver at purdue.edu > > > -----Original Message----- > From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu > Sent: Monday, November 05, 2012 11:33 AM > To: Fab Network > Subject: [labnetwork] gas room means of egress > > Dear Colleagues, > > I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. > > This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. > > How many doors does your gas room have? > > Thank you very much. > > Iulian > -- > iulian Codreanu, Ph.D. > Director of Operations, UD Nanofab > University of Delaware > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From gpl107 at psu.edu Tue Nov 6 12:42:48 2012 From: gpl107 at psu.edu (Lavallee, Guy P.) Date: Tue, 6 Nov 2012 17:42:48 +0000 Subject: [labnetwork] gas room means of egress In-Reply-To: References: <5097EA31.60406@udel.edu> Message-ID: Iulian, We just finished the build of our new facility here at PSU and I have a quick comment on the consultant's interpretation. We found that different consultants can have significantly different reads on the building / fire codes in your local. This is critical to understand from an owners standpoint because in the end a bad interpretation can come back to bite you. We had several issues related to consultants especially as it related to the Hazard Class rating of the facility and had to push hard to get the ones we questioned reviewed by other independent consultants. Here at PSU our HPM room has more than one egress door but that was based on the design / layout and one code consultants interpretation of the room. Having more than one egress point from a hazardous room seems logical but may not be practical or efficient based on its footprint. In the end you have to go through different scenarios that may occur in the room and how one would safely exit. If you determine there is a situation that could occur and having only one door would be detrimental than that would be a good reason to have a second egress door even though code only says you need one. Obviously in a situation like this it comes down to cost justification. Guy Penn State University's Nanofabrication Laboratory Lead Etch Engineer Materials Research Institute N-105 Millennium Science Complex (MSC Bldg) University Park, PA 16802 Email: gpl107 at psu.edu Phone: 814-865-9339 Cell: 814-777-0719 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Dennis Schweiger Sent: Monday, November 05, 2012 7:48 PM To: Iulian Codreanu Cc: Fab Network Subject: Re: [labnetwork] gas room means of egress Iulian, we have a single egress door from our flammable gas storage room, but there are two doors from our toxic gas room. One to the outside of the building, and one to the inside. Their proximity to each other (about 2 feet) though doesn't really meet with the egress layout you had in mind though. I'm guessing you're thinking about opposite ends of the storage locations. Dennis 734.647.2055 Ofc On Mon, Nov 5, 2012 at 11:32 AM, Iulian Codreanu > wrote: Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From vincent.luciani at nist.gov Tue Nov 6 14:24:36 2012 From: vincent.luciani at nist.gov (Luciani, Vincent) Date: Tue, 6 Nov 2012 14:24:36 -0500 Subject: [labnetwork] gas room means of egress In-Reply-To: <5097EA31.60406@udel.edu> References: <5097EA31.60406@udel.edu> Message-ID: <01F47D4EDEEC64488C10B767D15E4858101A1443CF@MBCLUSTER.xchange.nist.gov> Hello Iulian, I believe you are correct that you must have 2 exits. However, there are other contributing factors that need to be considered. We adhere strictly to the rules set forth by the appropriate NFPA codes. In this case you should use NFPA 318: Standard for the Protection of Semiconductor Fabrication Facilities, 2012 Edition along with NFPA-101 Life safety Code. These two documents will provide the relevant codes that will likely support or at least clarify the requirements. Good Luck, Vince Vincent K. Luciani NanoFab Manager Center for Nanoscale Science and Technology National Institute of Standards and Technology 100 Bureau Drive, MS 6201 Gaithersburg, MD 20899-6200 USA +1-301-975-2886 [cid:image001.jpg at 01CDBC2A.93CBD5B0] -----Original Message----- From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu Sent: Monday, November 05, 2012 11:33 AM To: Fab Network Subject: [labnetwork] gas room means of egress Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.jpg Type: image/jpeg Size: 6965 bytes Desc: image001.jpg URL: From rizik at intengr.com Tue Nov 6 21:12:51 2012 From: rizik at intengr.com (Rizik) Date: Tue, 6 Nov 2012 18:12:51 -0800 Subject: [labnetwork] gas room means of egress In-Reply-To: <50992576.4020405@lbl.gov> References: <5097EA31.60406@udel.edu> <6A848421F695C54A9210C1A873C96AC2068D1EEB@WPVEXCMBX04.purdue.lcl> <50992576.4020405@lbl.gov> Message-ID: <05bc01cdbc8d$649995d0$2dccc170$@com> Although a second exit is required by code when the H-Occupancy room is 200 sq.ft. or larger, a second exit is always a cheap safety assurance. Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of David A. Bunzow Sent: Tuesday, November 06, 2012 6:58 AM To: labnetwork at mtl.mit.edu Subject: Re: [labnetwork] gas room means of egress DITTO...ALWAYS 2...have your code consultant think life safety, not cost of dying. While code may not require it (and I didn't see which code and interpretation was being referenced), codes are merely the MINIMUM needed, not what you would want for yourself or your people. The gas room in TMF's nanofabrication facility has 2 egress doors, one at each end.../DAB David A. Bunzow User Facilities Program Manager The Molecular Foundry Materials Science Division Lawrence Berkeley National Laboratory 1 Cyclotron Road MS 67-3207 Berkeley, CA 94720 Office: 510-486-4574 FAX: 510-486-7424 Cell: 510-542-1747 On 11/5/2012 1:21 PM, Weaver, John R wrote: Always two! If you have a person working in the room and the incident happens between the person and the only exit, he/she is toast! I have doors at each end of my room so that no matter where the incident would occur there is a clear exit path from the room. John R. Weaver Facility Manager Birck Nanotechnology Center Purdue University (765) 494-5494 jrweaver at purdue.edu -----Original Message----- From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu Sent: Monday, November 05, 2012 11:33 AM To: Fab Network Subject: [labnetwork] gas room means of egress Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From agregg at abbiegregg.com Tue Nov 6 21:52:53 2012 From: agregg at abbiegregg.com (Abbie Gregg) Date: Tue, 6 Nov 2012 21:52:53 -0500 Subject: [labnetwork] gas room means of egress In-Reply-To: References: <5097EA31.60406@udel.edu> Message-ID: <5863FB4055D90542A7A7DAE0CEF2ACB00865D5A018@E2K7CCR1.netvigour.com> The answer is easy for Iullian. If the distance from the furthest point in the HPM room to the outside corridor, with 2 means of exit, is greater than 25 feet, then a second exit is needed from the HPM room. The second exit must go directly outside. If the HPM room is greater than 500 ft^2, a second exit is required as well. This is in the IBC codes of 2009. Earlier or local codes may be significantly different. Mark Winter, CSP, P.E. - Chemical Senior Technical Staff Process/Safety Lead Abbie Gregg, Inc 1130 E. University Dr., Suite 105 Tempe, AZ 85281 Phone: 480-446-0056, xt. 113 Cell: 480-330-1846 Fax: 480-446-8001 Abbie Gregg President Abbie Gregg, Inc. 1130 East University Drive, Suite 105 Tempe, Arizona 85281 Phone 480 446-8000 x 107 Cell 480-577-5083 FAX 480-446-8001 email agregg at abbiegregg.com website www.abbiegregg.com CONFIDENTIALITY NOTICE: All information contained in or attached to this email constitutes confidential information belonging to Abbie Gregg, Inc., its affiliates and subsidiaries and/or its clients. This email and any attachments are proprietary and/or confidential and are intended for business use of the addressee(s) only. All other uses or disclosures are strictly prohibited. If the reader is not the intended recipient you are hereby notified that the perusal, copying or dissemination of this email is strictly prohibited. If you have received this communication in error, please notify the sender, and delete all copies of this message and its attachments immediately. From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Dennis Schweiger Sent: Monday, November 05, 2012 5:48 PM To: Iulian Codreanu Cc: Fab Network Subject: Re: [labnetwork] gas room means of egress Iulian, we have a single egress door from our flammable gas storage room, but there are two doors from our toxic gas room. One to the outside of the building, and one to the inside. Their proximity to each other (about 2 feet) though doesn't really meet with the egress layout you had in mind though. I'm guessing you're thinking about opposite ends of the storage locations. Dennis 734.647.2055 Ofc On Mon, Nov 5, 2012 at 11:32 AM, Iulian Codreanu > wrote: Dear Colleagues, I am trying to influence a decision on a second means of egress from the gas room at the University of Delaware and your input is very much appreciated. This is the room where the cabinets for toxic, flammable, and pyrophoric as well as some panels for inert gases will be located. The room is adjacent to and separated from the cleanroom by a fire rated wall (I was told it is at least two hours-rated). The code consultant states that a second means of egress is not needed for this H2 occupancy room but I feel it is a must. How many doors does your gas room have? Thank you very much. Iulian -- iulian Codreanu, Ph.D. Director of Operations, UD Nanofab University of Delaware _______________________________________________ labnetwork mailing list labnetwork at mtl.mit.edu https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From rgc5 at psu.edu Tue Nov 13 08:08:08 2012 From: rgc5 at psu.edu (Cornwall, Robert G.) Date: Tue, 13 Nov 2012 13:08:08 +0000 Subject: [labnetwork] Penn State Nanofab Job Opportunity - Engineering Project Manager In-Reply-To: <112F5A9BC6B8DA44BB0BD3ACE2EAAA84A8029B41@Cirrus> References: <112F5A9BC6B8DA44BB0BD3ACE2EAAA84A8029B41@Cirrus> Message-ID: <112F5A9BC6B8DA44BB0BD3ACE2EAAA84A802E1C4@Cirrus> Engineering Project Manager (Senior Technical Liaison Officer) Nanofabrication Laboratory of the Materials Research Institute The Pennsylvania State University, University Park The Materials Research Institute at the Pennsylvania State University is seeking highly qualified candidates to match the technical needs of corporate and external academic researchers with the specialized capabilities offered by the Nanofabrication Laboratory with the purpose of increasing the number of external researchers using the Laboratory. The successful candidate will assist external researchers from diverse fields in designing and developing integrated process flows, and in coordinating the project administration with Laboratory staff, faculty, and consultants. Extensive background and experience in all aspects of device nanofabrication is required, including fully integrated lithographic, deposition, and etching processes. Previous experience in technical marketing, project management, and budget oversight is highly desirable. The successful candidate should have excellent communication, leadership, and time management skills as well as knowledge of policies and procedures related to intellectual property, grants and contracts, and IT resources. The Nanofabrication Laboratory comprises a 10,000 sq. ft. cleanroom with a nearly equivalent amount of support space, which is located within the newly constructed state-of-the-art Millennium Science Complex on the Penn State University Park campus (http://www.mri.psu.edu/). This interdisciplinary research complex also houses the Materials Characterization Laboratory, with cutting edge analytical and microscopy facilities, and numerous materials and life-sciences research laboratories. The fully staffed Nanofabrication Laboratory maintains and operates more than 70 nanofabrication and characterization tools, with a technical focus in heterogeneous integration of novel materials such as complex oxides, chalcogenides, graphene, etc. onto nontraditional substrates. The Laboratory is a member of the NSF National Nanotechnology Infrastructure Network (NNIN), and currently supports the nanofabrication needs of more than 500 researchers per year. Typically requires a Master's degree or higher plus two years of related experience, or an equivalent combination of education and experience. Degree in Engineering/Physical Sciences or related disciplines, and experience in process integration and technical management is preferred. Review of the applications will begin immediately and continue until the position is filled. To submit your application, please visit - http://psu.jobs/Search/Opportunities.html Robert Cornwall Managing Director - MRI 814-863-8735 -------------- next part -------------- An HTML attachment was scrubbed... URL: From julia.aebersold at louisville.edu Tue Nov 13 15:11:58 2012 From: julia.aebersold at louisville.edu (Aebersold,Julia W.) Date: Tue, 13 Nov 2012 20:11:58 +0000 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas Message-ID: I wanted to gather some information of aluminum anneal on a silicon wafer performed by other cleanrooms. We are using 5% forming gas with an anneal temp of 400C for ? hour with a 20C/min ramp up and ramp down However, I have also seen higher temps up to 475C, but was concerned about the flammability of 100% hydrogen per its MSDS. Cheers! Julia Aebersold, Ph.D. MNTC Cleanroom Manager Shumaker Research Building, Room 233 2210 South Brook Street University of Louisville Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From fouad.karouta at anu.edu.au Tue Nov 13 17:07:40 2012 From: fouad.karouta at anu.edu.au (Fouad Karouta) Date: Wed, 14 Nov 2012 09:07:40 +1100 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: References: Message-ID: <002a01cdc1eb$4cbc5a20$e6350e60$@anu.edu.au> Hi Julia, Pure H2 is commonly used in epitaxy reactors at temperature well above 600?C. MOCVD of GaAs/AlGaAs is performed at T=600-800C. In the past I did liquid phase epitaxy of GaAs/AlGaAs around 800C in pure H2. Moreover Flammability of H2 in air is between 4 to 80%. So in inert gas like N2 the flammability are different. Hope this would help. Fouad Karouta ********************************* Facility Manager ANFF ACT Node Research School of Physics and Engineering Australian National University ACT 0200, Canberra, Australia Tel: + 61 2 6125 7174 Mob: + 61 451 046 412 Email: fouad.karouta at anu.edu.au From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Aebersold,Julia W. Sent: Wednesday, 14 November 2012 7:12 AM To: Lab Network (labnetwork at mtl.mit.edu) Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas I wanted to gather some information of aluminum anneal on a silicon wafer performed by other cleanrooms. We are using 5% forming gas with an anneal temp of 400C for ? hour with a 20C/min ramp up and ramp down However, I have also seen higher temps up to 475C, but was concerned about the flammability of 100% hydrogen per its MSDS. Cheers! Julia Aebersold, Ph.D. MNTC Cleanroom Manager Shumaker Research Building, Room 233 2210 South Brook Street University of Louisville Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From shott at stanford.edu Tue Nov 13 20:08:39 2012 From: shott at stanford.edu (John Shott) Date: Tue, 13 Nov 2012 17:08:39 -0800 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: <002a01cdc1eb$4cbc5a20$e6350e60$@anu.edu.au> References: <002a01cdc1eb$4cbc5a20$e6350e60$@anu.edu.au> Message-ID: <50A2EF17.1030407@stanford.edu> Julia: Fouad is correct that things like epitaxial reactors and MOCVD equipment run pure hydrogen at high temperatures. They also have careful pre- and post-run purging to remove residual air before hydrogen is introduced and typically also have some form of hydrogen burning/scrubbing at the exhaust end. In short, epi reactors and MOCVD systems go to great lengths to make sure that oxygen and hydrogen NEVER mix at high temperatures. I certainly wouldn't want to be in the room if you tried to run pure hydrogen at 800 C in a typical horizontal annealing furnace. I suspect that Fouad would agree that this would be a very bad idea. Long ago, when running an oxidation furnace with a hydrogen torch to generate steam, I learned why you want to make sure that the ratio of hydrogen to oxygen is safely less than 2.0: I turned a cassette of wafers into fine glitter all over the laboratory floor. But, back to the issue of forming gas anneals: For a comparatively open forming gas anneal setup, I believe that your numbers of 5% forming gas at 400 C or slightly higher are right in the proper ball park. I'll be surprised if others aren't very close to this range in their own usage. We at Stanford run 4% forming gas and the great majority of our lab members likely do their annealing at either 400 or 450 C typically for about 30 minutes. The furnace used for this typically idles close to 400 C so there isn't too much of a ramp up/down even if the actual anneal will be at 450 C. At 450 you probably get slightly better annealing of interface traps than you would at 400 C ... but you can also see more in the way of hillock formation if you have aluminum or aluminum-alloy metalization on your wafers. Good luck, John On 11/13/2012 2:07 PM, Fouad Karouta wrote: > > Hi Julia, > > Pure H2 is commonly used in epitaxy reactors at temperature well above > 600?C. MOCVD of GaAs/AlGaAs is performed at T=600-800C. > > In the past I did liquid phase epitaxy of GaAs/AlGaAs around 800C in > pure H2. > > Moreover Flammability of H2 in air is between 4 to 80%. So in inert > gas like N2 the flammability are different. > > Hope this would help. > > Fouad Karouta > -------------- next part -------------- An HTML attachment was scrubbed... URL: From helenandersonpenn at gmail.com Tue Nov 13 10:48:21 2012 From: helenandersonpenn at gmail.com (Helen Anderson) Date: Tue, 13 Nov 2012 10:48:21 -0500 Subject: [labnetwork] Penn Lab Director position open Message-ID: Folks, We wish Iulian Codreanu well with his new opportunity at the University of Delaware, which is much closer to his home. We are seeking a person to refill the lab director position. If you know of qualified applicants, please encourage them to apply. jobs.hr.upenn.edu/applicants/Central?quickFind=196630 Thanks. -Helen Helen Anderson University of Pennsylvania From fouad.karouta at anu.edu.au Tue Nov 13 21:44:26 2012 From: fouad.karouta at anu.edu.au (Fouad Karouta) Date: Wed, 14 Nov 2012 13:44:26 +1100 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: <50A2EF17.1030407@stanford.edu> References: <002a01cdc1eb$4cbc5a20$e6350e60$@anu.edu.au> <50A2EF17.1030407@stanford.edu> Message-ID: <010301cdc211$f62784b0$e2768e10$@anu.edu.au> Hi, Indeed I do agree with John about the issue related to an open furnace tube. I assumed a sealed furnace tube with vacuum pump. Regards, Fouad From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of John Shott Sent: Wednesday, 14 November 2012 12:09 PM To: labnetwork at mtl.mit.edu; Aebersold,Julia Weyer Subject: Re: [labnetwork] Anneal temp for aluminum on silicon with forming gas Julia: Fouad is correct that things like epitaxial reactors and MOCVD equipment run pure hydrogen at high temperatures. They also have careful pre- and post-run purging to remove residual air before hydrogen is introduced and typically also have some form of hydrogen burning/scrubbing at the exhaust end. In short, epi reactors and MOCVD systems go to great lengths to make sure that oxygen and hydrogen NEVER mix at high temperatures. I certainly wouldn't want to be in the room if you tried to run pure hydrogen at 800 C in a typical horizontal annealing furnace. I suspect that Fouad would agree that this would be a very bad idea. Long ago, when running an oxidation furnace with a hydrogen torch to generate steam, I learned why you want to make sure that the ratio of hydrogen to oxygen is safely less than 2.0: I turned a cassette of wafers into fine glitter all over the laboratory floor. But, back to the issue of forming gas anneals: For a comparatively open forming gas anneal setup, I believe that your numbers of 5% forming gas at 400 C or slightly higher are right in the proper ball park. I'll be surprised if others aren't very close to this range in their own usage. We at Stanford run 4% forming gas and the great majority of our lab members likely do their annealing at either 400 or 450 C typically for about 30 minutes. The furnace used for this typically idles close to 400 C so there isn't too much of a ramp up/down even if the actual anneal will be at 450 C. At 450 you probably get slightly better annealing of interface traps than you would at 400 C ... but you can also see more in the way of hillock formation if you have aluminum or aluminum-alloy metalization on your wafers. Good luck, John On 11/13/2012 2:07 PM, Fouad Karouta wrote: Hi Julia, Pure H2 is commonly used in epitaxy reactors at temperature well above 600?C. MOCVD of GaAs/AlGaAs is performed at T=600-800C. In the past I did liquid phase epitaxy of GaAs/AlGaAs around 800C in pure H2. Moreover Flammability of H2 in air is between 4 to 80%. So in inert gas like N2 the flammability are different. Hope this would help. Fouad Karouta -------------- next part -------------- An HTML attachment was scrubbed... URL: From H.W.vanZeijl at tudelft.nl Wed Nov 14 08:12:08 2012 From: H.W.vanZeijl at tudelft.nl (Henk van Zeijl - EWI) Date: Wed, 14 Nov 2012 13:12:08 +0000 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: References: Message-ID: <4F4CC9CD6CD4E149902B16250C059918104ABB7E@srv365.tudelft.net> Dear Julia Aebersold This is an Al/Si(1%) alloy recipe in use at Delft university, the Netherlands PROCESS TEMPERATURE (in ?C) GASSES & FLOWS (in liter/min) TIME (in minutes) boat in 400 nitrogen: 3.0 5 stabilize 1 400 nitrogen: 3.0 5 stabilize2 400 nitrogen: 3.0 10 alloying 400 nitrogen: 3.0 hydrogen: 0.3 20 purge 400 nitrogen: 3.0 5 boat out 400 nitrogen: 3.0 5 We use Al(Si1%) to avoid junction spiking on shallow n+ p junctions. This recipe also improves the low current characteristics of bipolar npn transistors, see below (copy of lecture slides). [cid:image001.png at 01CDC272.0D7368E0][cid:image002.png at 01CDC272.0D7368E0] Kind regars, Henk van Zeijl Delft University of Technology / DIMES POBox 5053 NL-2600 GB DELFT The Netherlands phone: ++31 15 2781092 Mobile: ++31 6 24373305 fax: ++31 15 2787369 Email: h.w.vanzeijl at tudelft.nl From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Aebersold,Julia W. Sent: 13 November 2012 21:12 To: Lab Network (labnetwork at mtl.mit.edu) Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas I wanted to gather some information of aluminum anneal on a silicon wafer performed by other cleanrooms. We are using 5% forming gas with an anneal temp of 400C for ? hour with a 20C/min ramp up and ramp down However, I have also seen higher temps up to 475C, but was concerned about the flammability of 100% hydrogen per its MSDS. Cheers! Julia Aebersold, Ph.D. MNTC Cleanroom Manager Shumaker Research Building, Room 233 2210 South Brook Street University of Louisville Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 104149 bytes Desc: image001.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 93791 bytes Desc: image002.png URL: From H.W.vanZeijl at tudelft.nl Wed Nov 14 10:42:48 2012 From: H.W.vanZeijl at tudelft.nl (Henk van Zeijl - EWI) Date: Wed, 14 Nov 2012 15:42:48 +0000 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: <010301cdc211$f62784b0$e2768e10$@anu.edu.au> References: <002a01cdc1eb$4cbc5a20$e6350e60$@anu.edu.au> <50A2EF17.1030407@stanford.edu> <010301cdc211$f62784b0$e2768e10$@anu.edu.au> Message-ID: <4F4CC9CD6CD4E149902B16250C059918104ABF2D@srv365.tudelft.net> Hello, At Delft University we have an atmospheric exhaust system (scavenger) on the alloy furnace using 10% hydrogen in nitrogen, the system works fine since 1991. Kind regards, Henk Delft University of Technology / DIMES POBox 5053 NL-2600 GB DELFT The Netherlands phone: ++31 15 2781092 Mobile: ++31 6 24373305 fax: ++31 15 2787369 Email: h.w.vanzeijl at tudelft.nl From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Fouad Karouta Sent: 14 November 2012 03:44 To: labnetwork at mtl.mit.edu; 'Aebersold,Julia Weyer' Subject: Re: [labnetwork] Anneal temp for aluminum on silicon with forming gas Hi, Indeed I do agree with John about the issue related to an open furnace tube. I assumed a sealed furnace tube with vacuum pump. Regards, Fouad From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of John Shott Sent: Wednesday, 14 November 2012 12:09 PM To: labnetwork at mtl.mit.edu; Aebersold,Julia Weyer Subject: Re: [labnetwork] Anneal temp for aluminum on silicon with forming gas Julia: Fouad is correct that things like epitaxial reactors and MOCVD equipment run pure hydrogen at high temperatures. They also have careful pre- and post-run purging to remove residual air before hydrogen is introduced and typically also have some form of hydrogen burning/scrubbing at the exhaust end. In short, epi reactors and MOCVD systems go to great lengths to make sure that oxygen and hydrogen NEVER mix at high temperatures. I certainly wouldn't want to be in the room if you tried to run pure hydrogen at 800 C in a typical horizontal annealing furnace. I suspect that Fouad would agree that this would be a very bad idea. Long ago, when running an oxidation furnace with a hydrogen torch to generate steam, I learned why you want to make sure that the ratio of hydrogen to oxygen is safely less than 2.0: I turned a cassette of wafers into fine glitter all over the laboratory floor. But, back to the issue of forming gas anneals: For a comparatively open forming gas anneal setup, I believe that your numbers of 5% forming gas at 400 C or slightly higher are right in the proper ball park. I'll be surprised if others aren't very close to this range in their own usage. We at Stanford run 4% forming gas and the great majority of our lab members likely do their annealing at either 400 or 450 C typically for about 30 minutes. The furnace used for this typically idles close to 400 C so there isn't too much of a ramp up/down even if the actual anneal will be at 450 C. At 450 you probably get slightly better annealing of interface traps than you would at 400 C ... but you can also see more in the way of hillock formation if you have aluminum or aluminum-alloy metalization on your wafers. Good luck, John On 11/13/2012 2:07 PM, Fouad Karouta wrote: Hi Julia, Pure H2 is commonly used in epitaxy reactors at temperature well above 600?C. MOCVD of GaAs/AlGaAs is performed at T=600-800C. In the past I did liquid phase epitaxy of GaAs/AlGaAs around 800C in pure H2. Moreover Flammability of H2 in air is between 4 to 80%. So in inert gas like N2 the flammability are different. Hope this would help. Fouad Karouta -------------- next part -------------- An HTML attachment was scrubbed... URL: From whipp003 at umn.edu Wed Nov 14 20:37:21 2012 From: whipp003 at umn.edu (Tony Whipple) Date: Wed, 14 Nov 2012 19:37:21 -0600 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: References: Message-ID: <50A44751.9020201@umn.edu> Hello; At the University of Minnesota we use a10 % mixture on an atmospheric system with the normal alloy temperature being 425C also have a 450C alloy process, time of 30 min. Besides the normal safety items like over temperature limits, we have limited the time the door can be open during loading of the wafers. If this time is exceeded the recipe goes to an abort step. This is done to reduce the amount of firing on the end zone if the tube was allowed to stay open too long. Regards, Tony Whipple On 11/13/2012 2:11 PM, Aebersold,Julia W. wrote: > > I wanted to gather some information of aluminum anneal on a silicon > wafer performed by other cleanrooms. We are using 5% forming gas > with an anneal temp of 400C for ? hour with a 20C/min ramp up and > ramp down However, I have also seen higher temps up to 475C, but was > concerned about the flammability of 100% hydrogen per its MSDS. > > Cheers! > > Julia Aebersold, Ph.D. > > MNTC Cleanroom Manager > > Shumaker Research Building, Room 233 > > 2210 South Brook Street > > University of Louisville > > Louisville, KY 40292 > > 502-852-1572 > > http://louisville.edu/micronano/ > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: From julia.aebersold at louisville.edu Thu Nov 15 10:02:28 2012 From: julia.aebersold at louisville.edu (Aebersold,Julia W.) Date: Thu, 15 Nov 2012 15:02:28 +0000 Subject: [labnetwork] Anneal temp for aluminum on silicon with forming gas In-Reply-To: <50A44751.9020201@umn.edu> References: <50A44751.9020201@umn.edu> Message-ID: I wish to thank everyone for their very informative answers to my anneal questions. We will use the information and integrate it with our anneal processes. Cheers! Julia Aebersold, Ph.D. MNTC Cleanroom Manager Shumaker Research Building, Room 233 2210 South Brook Street University of Louisville Louisville, KY 40292 502-852-1572 http://louisville.edu/micronano/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From lej at danchip.dtu.dk Fri Nov 16 07:24:42 2012 From: lej at danchip.dtu.dk (Leif Johansen) Date: Fri, 16 Nov 2012 13:24:42 +0100 Subject: [labnetwork] Issue with diborane in nitrogen mixture Message-ID: <39838FA4BF2F9A43AE3918CAD0F6AF1718683FFD0D@WINEXCHANGE3.win.dtu.dk> Dear all, Here at DTU Danchip we are facing some difficulties with diborane in nitrogen mixtures. I the recent months we have made the following observations with our 3% diborane in nitrogen mixture: ? Approximately half year ago, the safety valve opened up due to a too large overpressure on the secondary side of the regulator. Usually, the secondary pressure is set to 1-2 Bars overpressure. The safety valve will open up at pressures exceeding ca. 7 Bars. ? At that time we believed that the incident was caused by a faulty gas panel regulator. So we changed the regulator and continued to use the gas. ? However, in the past month or so we have seen that the pressure rises from the setpoint of 1.5 Bars to around 3 Bars. If we then consume gas from the line, the pressure has been observed to drop in discrete steps rather than in a smooth way. ? This week the pressure suddenly increased dramatically again, leading to a new safety valve release. We have now shut down the gas line. My questions are : 1. The bottle is from March 2010. I have once read that over time diborane decomposes into higher order borohydrides, which, unlike diborane, are solid and can clog orifices and nozzles. This phenomenon has already been addressed by Bob Hamilton in this forum. Is our diborane bottle simply too old and emits "ear wax" into the gas line? 2. The bottle is located in a gas bunker outside, where the temperature can vary quite a bit over the four seasons. The specified temperature range is 0?C to 40?C (32?F to 104?F ). What happens if the temperature exceeds this range? 3. The gas panel regulator is a "Rotatrex SI 240 V" gas regulator (240 Bar primary side, 7 Bar secondary side). I have read that certain materials should be avoided inside valves and regulators used for diborane gas. As far as I can read on the data sheet, the body is made of 316 L steel, the diaphragm is made of Hasetlloy and the valve seat is made of Vespel or PVDF. Can anyone comment on whether our present regulator is suited at all to handle diborane? If not, can anybody recommend a better alternative? These issues are causing considerable down-times of our diborane consuming equipment, so I would very much appreciate any information you could share which could help us solve the problem. Leif S. Johansen Head of Operations DTU Danchip Technical University of Denmark [cid:image001.gif at 01CDC3FC.D1B530E0] Danchip ?rsteds Plads, Byg. 347 2800 Lyngby Direct +45 45255713 Mobile +45 25348992 lej at danchip.dtu.dk www.danchip.dtu.dk/ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.gif Type: image/gif Size: 1055 bytes Desc: image001.gif URL: From spaolini at cns.fas.harvard.edu Fri Nov 16 10:29:14 2012 From: spaolini at cns.fas.harvard.edu (Paolini, Steven) Date: Fri, 16 Nov 2012 10:29:14 -0500 Subject: [labnetwork] Issue with diborane in nitrogen mixture In-Reply-To: <39838FA4BF2F9A43AE3918CAD0F6AF1718683FFD0D@WINEXCHANGE3.win.dtu.dk> References: <39838FA4BF2F9A43AE3918CAD0F6AF1718683FFD0D@WINEXCHANGE3.win.dtu.dk> Message-ID: <8F95EA77ACBF904A861E580B44288EFD9C21C17CBF@FASXCH02.fasmail.priv> I have had extensive grief with this same scenario when I was in industry. To make a long story short, Diborane in the absence of Hydrogen will form solid particles because of the cooling effect (Joule-Thomson) of the regulator reducing the pressure. The solids are what is known as Decaborane (B10H6). Unfortunately, they form mostly on the seat of the bonnet and allow the regulator to "creep" resulting in the high pressure leaking past the regulator and into the low pressure side. Some engineers have tried to chill the bottle to reduce the Joule Thomson effect but that just resulted in the material forming elsewhere in the circuit. Your regulator is certainly suited for handling Diborane but you must get used to the fact that they will degrade over time as this material is formed. My suggestions are as follows: 1) Replace the regulator with a two stage unit, this will extend the failure time. 2) Specify a large CV on all new regulators, this will extend the life because the effect will be on a larger surface area. 3) "Stack" regulators in series, The less that the regulator has to reduce pressure, the less Joule Thomson effect will happen. This is expensive and clumsy but a colleague of mine tells me that he has run this set up for three years without incident. 4) Best method for an absolute cure is to (if you can) switch your mixture to H2 instead of N2, you may not be able to do this depending on your process but if you can, it will eliminate the problem. I used to run 5000 PPM B2H6 in N2 as a dopant to a furnace, H2 was out of the question because the process was close to the auto ignition point of H2. I used Tescom 1/2" bonnet regulators and swapped them out every three months. If we didn't change them regularly, they would begin to creep and ultimately fail. It is a phenomenon that you have to deal with in an expensive manner. Steve Paolini Harvard University Center for Nanoscale Systems From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Leif Johansen Sent: Friday, November 16, 2012 7:25 AM To: Lab Network (labnetwork at mtl.mit.edu) Subject: [labnetwork] Issue with diborane in nitrogen mixture Dear all, Here at DTU Danchip we are facing some difficulties with diborane in nitrogen mixtures. I the recent months we have made the following observations with our 3% diborane in nitrogen mixture: ? Approximately half year ago, the safety valve opened up due to a too large overpressure on the secondary side of the regulator. Usually, the secondary pressure is set to 1-2 Bars overpressure. The safety valve will open up at pressures exceeding ca. 7 Bars. ? At that time we believed that the incident was caused by a faulty gas panel regulator. So we changed the regulator and continued to use the gas. ? However, in the past month or so we have seen that the pressure rises from the setpoint of 1.5 Bars to around 3 Bars. If we then consume gas from the line, the pressure has been observed to drop in discrete steps rather than in a smooth way. ? This week the pressure suddenly increased dramatically again, leading to a new safety valve release. We have now shut down the gas line. My questions are : 1. The bottle is from March 2010. I have once read that over time diborane decomposes into higher order borohydrides, which, unlike diborane, are solid and can clog orifices and nozzles. This phenomenon has already been addressed by Bob Hamilton in this forum. Is our diborane bottle simply too old and emits "ear wax" into the gas line? 2. The bottle is located in a gas bunker outside, where the temperature can vary quite a bit over the four seasons. The specified temperature range is 0?C to 40?C (32?F to 104?F ). What happens if the temperature exceeds this range? 3. The gas panel regulator is a "Rotatrex SI 240 V" gas regulator (240 Bar primary side, 7 Bar secondary side). I have read that certain materials should be avoided inside valves and regulators used for diborane gas. As far as I can read on the data sheet, the body is made of 316 L steel, the diaphragm is made of Hasetlloy and the valve seat is made of Vespel or PVDF. Can anyone comment on whether our present regulator is suited at all to handle diborane? If not, can anybody recommend a better alternative? These issues are causing considerable down-times of our diborane consuming equipment, so I would very much appreciate any information you could share which could help us solve the problem. Leif S. Johansen Head of Operations DTU Danchip Technical University of Denmark [cid:image001.gif at 01CDC3E3.083F4890] Danchip ?rsteds Plads, Byg. 347 2800 Lyngby Direct +45 45255713 Mobile +45 25348992 lej at danchip.dtu.dk www.danchip.dtu.dk/ -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.gif Type: image/gif Size: 1055 bytes Desc: image001.gif URL: From hathaway at cns.fas.harvard.edu Fri Nov 16 11:11:41 2012 From: hathaway at cns.fas.harvard.edu (Mac Hathaway) Date: Fri, 16 Nov 2012 11:11:41 -0500 Subject: [labnetwork] 2012 NNIN ALD Symposium at Harvard CNS In-Reply-To: <50A44751.9020201@umn.edu> References: <50A44751.9020201@umn.edu> Message-ID: <50A665BD.4050607@cns.fas.harvard.edu> Hello All, This is Mac Hathaway, at the Harvard Center for Nanoscale Systems. I'm writing to let you know about the*2012 NNIN ALD Symposium*, to be held on*Nov. 29-30, 2012*, at*Harvard University, in Cambridge, MA*. Each of you is cordially invited to join us in Cambridge for this, the latest in a series of NNIN process workshops that have been held at various NNIN sites over the last several years. We are currently planning a 2-day program at Harvard CNS which will consist of the following: *Day 1*. (NNIN Staff only) A one-day staff "current status" review of NNIN ALD systems and capabilities at the various NNIN sites, with plenty of time for informal "shop talk." *Day 2*. A series of brief*ALD Vendor Presentations*, including: *ALD Nanosolutions Arradiance Beneq Oxford Instruments Picosun* Three*Invited Talks* by noted experts in the field of ALD: *Prof. Roy Gordon, Harvard University Dr. Jeffrey Elam, Argonne National Lab Prof. Gregory Parson, North Carolina State University* A ~1-2 hour*ALD User Seminar*, in which we plan to present a short review of the "day one" results, with a presentation one or two highlights of current staff work at NNIN sites, and then a Q&A session. There will be no cost for this program, and it will be fully catered (breakfast and lunch). Day One will be open to**NNIN staff only, and *Day Two will be open to the public*, including members of the CNS community, users and faculty, as well as others in the NNIN network. The dates of this program are*Thursday and Friday, Nov. 29-30, 2012 (concurrent with MRS Fall Meeting in Boston)*. Registration is now open. You can visit our "Event Page" here: www.cns.fas.harvard.edu/ALD-2012 *Hotels and B&Bs -* There is the usual complement of hotels within walking distance (not more than 1/2 hour), including the Sheraton Commander, The Inn at Harvard , The Charles Hotel, etc. Also, there several B&Bs within a few hundred yards of the symposium rooms, including The Irving House (irvinghouse.com), The Harding House (harding-house.com, 125-165/night). There are three rooms available at_A Bed and Breakfast in Cambridge_ (cambridgebnb.com, $155, shared bath). Note that some rooms will have common (not private) bathrooms. *Food* - Breakfast and lunch will be available both days. If you are interested in attending, please sign up at your earliest convenience. If you know of others who would be interested in attending either day of the Symposium, please forward this as appropriate. Please contact Mac Hathaway (hathaway at cns.fas.harvard.edu ) with any questions. On behalf of the organizing committee(Mac Hathaway and Philippe de Rouffignac - Harvard CNS, Vince Genova - Cornell CNF, and Michelle Rincon - Stanford SNF), I thank you for your attention. Sincerely, Mac Hathaway Senior Process Engineer Harvard Center for Nanoscale Systems 617-495-9012 (office) 617-259-0859 (cell) hathaway at cns.fas.harvard.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: From conrad at Princeton.EDU Fri Nov 16 16:34:48 2012 From: conrad at Princeton.EDU (Conrad L. Silvestre) Date: Fri, 16 Nov 2012 21:34:48 +0000 Subject: [labnetwork] Sapphire Wafers in Silicon Oxidation Furnaces Message-ID: <942F7C9560506B479A2B7D73DB9F98D21749A9C2@CSGMBX201W.pu.win.princeton.edu> Do any problems arise for conventional Silicon CMOS furnace oxidation processes if prime grade sapphire wafers are put through the dry or wet oxidation process at 1000?C? Conrad Silvestre Department of Electrical Engineering C430 EQuad, CN-5263 Princeton University Princeton, New Jersey 08544-5263 -------------- next part -------------- An HTML attachment was scrubbed... URL: From bill at eecs.berkeley.edu Fri Nov 16 22:50:39 2012 From: bill at eecs.berkeley.edu (Bill Flounders) Date: Fri, 16 Nov 2012 19:50:39 -0800 Subject: [labnetwork] Issue with diborane in nitrogen mixture In-Reply-To: <8F95EA77ACBF904A861E580B44288EFD9C21C17CBF@FASXCH02.fasmail.priv> References: <39838FA4BF2F9A43AE3918CAD0F6AF1718683FFD0D@WINEXCHANGE3.win.dtu.dk> <8F95EA77ACBF904A861E580B44288EFD9C21C17CBF@FASXCH02.fasmail.priv> Message-ID: <50A7098F.80205@eecs.berkeley.edu> All, Very interesting. I appreciate Lief's recall of Bob Hamilton's (UC Berkeley) experience with polymerized diborane and Steve Paolimi's (Harvard) experience with polymerized diborane (decaborane) formation possibly being caused by Joule-Thomson cooling. New to me is Steve's information that diborane mixtures with hydrogen are not subject to this phenomena. At question then is the following: 1. Does dilution in H2 avoid the problem because hydrogen is one of the few gases that does not experience Joule-Thomsen cooling; or, 2. Does dilution in H2 avoid the problem because hydrogen prevents polymerization by constantly saturating any potential cross link sites; i.e., it always drives the equilibrium toward monomer not polymer. If number1 is correct, then dilution in helium should also solve the problem - and I suspect it does not. I expect number 2 is more important and Joule-Thomsen cooling is only partially (if at all) responsible for polymerization. I expect polymerization of stored diborane, enhanced by the cylinder experiencing temperature extremes (> 40 C) in an outside gas bunker is the issue. (Note, residues are common on the regulator high pressure side also - not just the low pressure side.) I expect cylinders are cooled to slow the polymerization reaction, not to decrease Joule-Thomsen cooling. Cooling cylinders buys time, but that's all. Some information on diborane decomposition is attached. This gas phase analysis article does not even address the non volatile decomposition products (polymers like decaborane) but the temp/decomposition relationship is clear. Suggestion: What if you use 3% B2H6 / 4% H2 / balance N2 The hydrogen pushes the equilibrium to diborane but the concentration does not raise any H2 handling concerns. Bill Flounders UC Berkeley Paolini, Steven wrote: > > I have had extensive grief with this same scenario when I was in > industry. To make a long story short, Diborane in the absence of > Hydrogen will form solid particles because of the cooling effect > (Joule-Thomson) of the regulator reducing the pressure. The solids > are what is known as Decaborane (B10H6). Unfortunately, they form > mostly on the seat of the bonnet and allow the regulator to "creep" > resulting in the high pressure leaking past the regulator and into the > low pressure side. Some engineers have tried to chill the bottle to > reduce the Joule Thomson effect but that just resulted in the material > forming elsewhere in the circuit. > > Your regulator is certainly suited for handling Diborane but you must > get used to the fact that they will degrade over time as this material > is formed. My suggestions are as follows: > > 1)Replace the regulator with a two stage unit, this will extend the > failure time. > > 2)Specify a large CV on all new regulators, this will extend the life > because the effect will be on a larger surface area. > > 3)"Stack" regulators in series, The less that the regulator has to > reduce pressure, the less Joule Thomson effect will happen. This is > expensive and clumsy but a colleague of mine tells me that he has run > this set up for three years without incident. > > 4)Best method for an absolute cure is to (if you can) switch your > mixture to H2 instead of N2, you may not be able to do this depending > on your process but if you can, it will eliminate the problem. > > I used to run 5000 PPM B2H6 in N2 as a dopant to a furnace, H2 was out > of the question because the process was close to the auto ignition > point of H2. I used Tescom 1/2" bonnet regulators and swapped them out > every three months. If we didn't change them regularly, they would > begin to creep and ultimately fail. It is a phenomenon that you have > to deal with in an expensive manner. > > Steve Paolini > > Harvard University Center for Nanoscale Systems > > *From:*labnetwork-bounces at mtl.mit.edu > [mailto:labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Leif Johansen > *Sent:* Friday, November 16, 2012 7:25 AM > *To:* Lab Network (labnetwork at mtl.mit.edu) > *Subject:* [labnetwork] Issue with diborane in nitrogen mixture > > Dear all, > > Here at DTU Danchip we are facing some difficulties with diborane in > nitrogen mixtures. > > I the recent months we have made the following observations with our > 3% diborane in nitrogen mixture: > > ?Approximately half year ago, the safety valve opened up due to a too > large overpressure on the secondary side of the regulator. Usually, > the secondary pressure is set to 1-2 Bars overpressure. The safety > valve will open up at pressures exceeding ca. 7 Bars. > > ?At that time we believed that the incident was caused by a faulty gas > panel regulator. So we changed the regulator and continued to use the > gas. > > ?However, in the past month or so we have seen that the pressure rises > from the setpoint of 1.5 Bars to around 3 Bars. If we then consume gas > from the line, the pressure has been observed to drop in discrete > steps rather than in a smooth way. > > ?This week the pressure suddenly increased dramatically again, leading > to a new safety valve release. We have now shut down the gas line. > > My questions are : > > 1.The bottle is from March 2010. I have once read that over time > diborane decomposes into higher order borohydrides, which, unlike > diborane, are solid and can clog orifices and nozzles. This phenomenon > has already been addressed by Bob Hamilton in this forum. Is our > diborane bottle simply too old and emits "ear wax" into the gas line? > > 2.The bottle is located in a gas bunker outside, where the temperature > can vary quite a bit over the four seasons. The specified temperature > range is 0?C to 40?C (32?F to 104?F ). What happens if the temperature > exceeds this range? > > 3.The gas panel regulator is a "Rotatrex SI 240 V" gas regulator (240 > Bar primary side, 7 Bar secondary side). I have read that certain > materials should be avoided inside valves and regulators used for > diborane gas. As far as I can read on the data sheet, the body is > made of 316 L steel, the diaphragm is made of Hasetlloy and the valve > seat is made of Vespel or PVDF. Can anyone comment on whether our > present regulator is suited at all to handle diborane? If not, can > anybody recommend a better alternative? > > These issues are causing considerable down-times of our diborane > consuming equipment, so I would very much appreciate any information > you could share which could help us solve the problem. > > *Leif S. Johansen * > > Head of Operations > > DTU Danchip > > *Technical University of Denmark* > > > > http://www.dtu.dk/images/DTU_email_logo_01.gif > > Danchip > > ?rsteds Plads, Byg. 347 > > 2800 Lyngby > > Direct +45 45255713 > > Mobile +45 25348992 > > lej at danchip.dtu.dk > > www.danchip.dtu.dk/ > > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/gif Size: 1055 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Diborane_decomposition_2005.pdf Type: application/x-pdf Size: 544592 bytes Desc: not available URL: From rpollina at umich.edu Wed Nov 21 08:32:06 2012 From: rpollina at umich.edu (Robert Pollina) Date: Wed, 21 Nov 2012 08:32:06 -0500 Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Message-ID: Good morning, I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan. Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide solution is sprayed over a "whiffle-ball-like" material, and a favorable PH is reached before the air is vented to atmosphere. The NaOH solution is collected in a lower tank and recirculated to the spray heads. PH sensors and Conductivity sensors call for more NaOH and city supplied fresh water as needed. Problem: Large amounts of Fusarium , Negative rod and Rototurula bacterias and fungi are created in the tank and must be removed to keep the Scrubber operating properly. This by-product is removed almost daily, often exceeding five gallons of concentrated solution. I'm hoping someone has experience with this same equipment and unwanted Fusarium growth. How do we better control production of this by-product? What are the proper safety procedures for maintenance staff? Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? Any assistance in this matter would be greatly appreciated. Robert Pollina University of Michigan Electrical Engineering and Computer Science Nanofabrication lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From rizik at intengr.com Sun Nov 25 09:44:26 2012 From: rizik at intengr.com (Rizik) Date: Sun, 25 Nov 2012 06:44:26 -0800 Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: References: Message-ID: <0b6d01cdcb1b$5ea130b0$1be39210$@com> Please try to answer the following questions before we provide our recommendation: 1. Daily removal of 5-gallons of concentrated solution - Do you mean caustic solution? If yes, what is the concentration? 2. Is NaOH injection to the recirculating water stream being controlled by a pH Controller to maintained a predetermined pH level? 3. What are you trying to scrub? 4. What is the makeup water flow rate? 5. Doe you control Total Dissolved Solids in the recirculating water? If yes, is it controlled by a TDS sensor & controller? 6. Does the recirc water go through a periodic purge cycle or does it continue to circulate and water is replenished only when water level in the basin drops? Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Robert Pollina Sent: Wednesday, November 21, 2012 5:32 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Good morning, I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan. Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide solution is sprayed over a "whiffle-ball-like" material, and a favorable PH is reached before the air is vented to atmosphere. The NaOH solution is collected in a lower tank and recirculated to the spray heads. PH sensors and Conductivity sensors call for more NaOH and city supplied fresh water as needed. Problem: Large amounts of Fusarium , Negative rod and Rototurula bacterias and fungi are created in the tank and must be removed to keep the Scrubber operating properly. This by-product is removed almost daily, often exceeding five gallons of concentrated solution. I'm hoping someone has experience with this same equipment and unwanted Fusarium growth. How do we better control production of this by-product? What are the proper safety procedures for maintenance staff? Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? Any assistance in this matter would be greatly appreciated. Robert Pollina University of Michigan Electrical Engineering and Computer Science Nanofabrication lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From kuhn1 at purdue.edu Mon Nov 26 16:32:10 2012 From: kuhn1 at purdue.edu (Kuhn, Jeffrey G) Date: Mon, 26 Nov 2012 21:32:10 +0000 Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: <0b6d01cdcb1b$5ea130b0$1be39210$@com> References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> Message-ID: <06C167B22748364D85BCA1AA812FDA1A07178294@WPVEXCMBX02.purdue.lcl> Robert, We have a large Harrington scrubber here at Birck, but it operates in a somewhat different way than what you describe. The "scrubbing agent" in our case is circulated water - not NaOH. Caustic is used only as needed to maintain the pH within the desired range. Ideally, you would want your circulating water to have an approximately neutral pH and not add caustic until it drops below at least 7.0. What I believe you are referring to when you mention the "lower tank" is actually the sump itself. Perhaps your design is different??? Just for reference, our scrubber is rated for 42,000 cfm and our circulation rate is about 400 GPM. We perform monthly bacteria testing using dip slides and, when needed, add a measured amount of isothazilinone-based biocide to kill the bacteria. This is only needed once or twice per year, usually in the summer months. We have never had to shut down for removal of the types of biological material you mention. Our fouling issues were always related to lime scale due to hard water make-up, but that issue has been mitigated by the introduction of softened make-up water. In my opinion, you should never need to deal with removal of biological material if your scrubber is operating correctly. I totally agree with Rizik in his response below as to the need for answers to his questions. I would also add that you need to control both your conductivity via periodic blow-down, and should minimize your cycles of concentration (depending on the make-up water parameters) to around 2-3 cycles. You should not let the pH get too high. Around pH = 9.5 is the upper limit I'd like to see. It is not so much the pH of the water that does the scrubbing, but rather the water itself. The addition of caustic is simply to keep the pH within certain limits so it can be discharged to your POTW (or WWT system if you have it), and to protect internal components from corrosion. Regards, Jeff Kuhn Facility Engineer Birck Nanotechnology Center Purdue University 1205 W. State St. West Lafayette, IN 47907 Ph: (765) 496-8329 Fax: (765) 496-2018 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Rizik Sent: Sunday, November 25, 2012 9:44 AM To: 'Robert Pollina'; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Please try to answer the following questions before we provide our recommendation: 1. Daily removal of 5-gallons of concentrated solution - Do you mean caustic solution? If yes, what is the concentration? 2. Is NaOH injection to the recirculating water stream being controlled by a pH Controller to maintained a predetermined pH level? 3. What are you trying to scrub? 4. What is the makeup water flow rate? 5. Doe you control Total Dissolved Solids in the recirculating water? If yes, is it controlled by a TDS sensor & controller? 6. Does the recirc water go through a periodic purge cycle or does it continue to circulate and water is replenished only when water level in the basin drops? Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Robert Pollina Sent: Wednesday, November 21, 2012 5:32 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Good morning, I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan. Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide solution is sprayed over a "whiffle-ball-like" material, and a favorable PH is reached before the air is vented to atmosphere. The NaOH solution is collected in a lower tank and recirculated to the spray heads. PH sensors and Conductivity sensors call for more NaOH and city supplied fresh water as needed. Problem: Large amounts of Fusarium , Negative rod and Rototurula bacterias and fungi are created in the tank and must be removed to keep the Scrubber operating properly. This by-product is removed almost daily, often exceeding five gallons of concentrated solution. I'm hoping someone has experience with this same equipment and unwanted Fusarium growth. How do we better control production of this by-product? What are the proper safety procedures for maintenance staff? Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? Any assistance in this matter would be greatly appreciated. Robert Pollina University of Michigan Electrical Engineering and Computer Science Nanofabrication lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From rizik at intengr.com Mon Nov 26 18:48:18 2012 From: rizik at intengr.com (Rizik) Date: Mon, 26 Nov 2012 15:48:18 -0800 Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: <06C167B22748364D85BCA1AA812FDA1A07178294@WPVEXCMBX02.purdue.lcl> References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> <06C167B22748364D85BCA1AA812FDA1A07178294@WPVEXCMBX02.purdue.lcl> Message-ID: <0d8a01cdcc30$8497a680$8dc6f380$@com> Hi Jeff, Excellent analysis. Our company's (IES) standard scrubbed exhaust system design is to provide not only caustic injection controlled by a pH probe & Controller but a Conductivity meter to monitor water conductivity which opens a purge solenoid valve to allow releasing about 5 gpm of scrubber water, which will be replenished when the float valve drops below the high limit or in the case of a controlled makeup water, when the LIT senses a drop in water level, then a 2" control valve would open to replenish the discharged water fast enough to prevent a vortex from forming and cavitating the pumps. In addition, in a lot of cases we introduce a biocide injection system to keep bacteria in check. In the old days when I used to work as a Semiconductor Facility Engineer, we used to shock each scrubber with a gallon or two of bleach. I agree with you that NOT ADDING FRESH water period will increase the cycles of concentration and therefore TDS concentration. We recommend the following: 1. Add an automatic purge system using a conductivity monitor and controller 2. Add a continuous SOFT water makeup of about 1 to 2 gpm. 3. Add an automatic biocide injection system 4. Provide semiannual basin cleaning using a wet vac / Pool vacuum cleaner Then, enjoy a nice running scrubber. Take care, Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: Kuhn, Jeffrey G [mailto:kuhn1 at purdue.edu] Sent: Monday, November 26, 2012 1:32 PM To: 'Rizik'; 'Robert Pollina'; labnetwork at mtl.mit.edu Subject: RE: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Robert, We have a large Harrington scrubber here at Birck, but it operates in a somewhat different way than what you describe. The "scrubbing agent" in our case is circulated water - not NaOH. Caustic is used only as needed to maintain the pH within the desired range. Ideally, you would want your circulating water to have an approximately neutral pH and not add caustic until it drops below at least 7.0. What I believe you are referring to when you mention the "lower tank" is actually the sump itself. Perhaps your design is different??? Just for reference, our scrubber is rated for 42,000 cfm and our circulation rate is about 400 GPM. We perform monthly bacteria testing using dip slides and, when needed, add a measured amount of isothazilinone-based biocide to kill the bacteria. This is only needed once or twice per year, usually in the summer months. We have never had to shut down for removal of the types of biological material you mention. Our fouling issues were always related to lime scale due to hard water make-up, but that issue has been mitigated by the introduction of softened make-up water. In my opinion, you should never need to deal with removal of biological material if your scrubber is operating correctly. I totally agree with Rizik in his response below as to the need for answers to his questions. I would also add that you need to control both your conductivity via periodic blow-down, and should minimize your cycles of concentration (depending on the make-up water parameters) to around 2-3 cycles. You should not let the pH get too high. Around pH = 9.5 is the upper limit I'd like to see. It is not so much the pH of the water that does the scrubbing, but rather the water itself. The addition of caustic is simply to keep the pH within certain limits so it can be discharged to your POTW (or WWT system if you have it), and to protect internal components from corrosion. Regards, Jeff Kuhn Facility Engineer Birck Nanotechnology Center Purdue University 1205 W. State St. West Lafayette, IN 47907 Ph: (765) 496-8329 Fax: (765) 496-2018 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Rizik Sent: Sunday, November 25, 2012 9:44 AM To: 'Robert Pollina'; labnetwork at mtl.mit.edu Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Please try to answer the following questions before we provide our recommendation: 1. Daily removal of 5-gallons of concentrated solution - Do you mean caustic solution? If yes, what is the concentration? 2. Is NaOH injection to the recirculating water stream being controlled by a pH Controller to maintained a predetermined pH level? 3. What are you trying to scrub? 4. What is the makeup water flow rate? 5. Doe you control Total Dissolved Solids in the recirculating water? If yes, is it controlled by a TDS sensor & controller? 6. Does the recirc water go through a periodic purge cycle or does it continue to circulate and water is replenished only when water level in the basin drops? Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Robert Pollina Sent: Wednesday, November 21, 2012 5:32 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Good morning, I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan. Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide solution is sprayed over a "whiffle-ball-like" material, and a favorable PH is reached before the air is vented to atmosphere. The NaOH solution is collected in a lower tank and recirculated to the spray heads. PH sensors and Conductivity sensors call for more NaOH and city supplied fresh water as needed. Problem: Large amounts of Fusarium , Negative rod and Rototurula bacterias and fungi are created in the tank and must be removed to keep the Scrubber operating properly. This by-product is removed almost daily, often exceeding five gallons of concentrated solution. I'm hoping someone has experience with this same equipment and unwanted Fusarium growth. How do we better control production of this by-product? What are the proper safety procedures for maintenance staff? Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? Any assistance in this matter would be greatly appreciated. Robert Pollina University of Michigan Electrical Engineering and Computer Science Nanofabrication lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From rpollina at umich.edu Tue Nov 27 07:36:34 2012 From: rpollina at umich.edu (Robert Pollina) Date: Tue, 27 Nov 2012 07:36:34 -0500 Subject: [labnetwork] Fwd: Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> Message-ID: Struggling with Scrubber equipment and sending e-mails! Hope you saw this e-mail Michael and Jeff. ---------- Forwarded message ---------- From: Robert Pollina Date: Mon, Nov 26, 2012 at 7:50 AM Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. To: Rizik Michael, Thanks for the reply. I will provide some details of our operation. The five gallons of by-product I mentioned refers to a yellow-brown skin of Fusarium fungus and Negative Rod bacteria that forms on the surface of the recirculating tank. This material forms, grows and clogs the spray heads and pumps in the system. This material is removed by hand each day. The ph of the water in the recirculating tank is maintained between 7.5 and 9.5. The ph is controlled with a ph sensor in the tank and an automated Sodium Hydroxide (50% solution) feed pump system. A constant flow of fresh "city provided" water is maintained at 1/2 gallon per minute to make up for evaporation. We use this Scrubber system to scrub the acidic fume hood exhaust air from our labs. A conductivity sensor helps to maintain a solution that can efficiently deliver the desired result. A manual "blow-down" valve adds fresh water to the system while ejecting old tank water to the drain to assist in maintaining a conductivity reading below 5000u. The Scrubber tank is completely drained and refilled each week as total dissolved solids always exceeds the ability for a quick blow-down to lower conductivity to a good level after 5-7 days of lab operation. An in-line strainer collects the same material and is cleaned daily. I hope this furthers your understanding of our equipment (Harrington Scrubber) and procedures. Looking forward to hearing from you, let me know if more info is needed -Robert. On Sun, Nov 25, 2012 at 9:44 AM, Rizik wrote: > Please try to answer the following questions before we provide our > recommendation:**** > > ** ** > > **1. **Daily removal of 5-gallons of concentrated solution - Do you > mean caustic solution? If yes, what is the concentration?**** > > **2. **Is NaOH injection to the recirculating water stream being > controlled by a pH Controller to maintained a predetermined pH level?**** > > **3. **What are you trying to scrub?**** > > **4. **What is the makeup water flow rate?**** > > **5. **Doe you control Total Dissolved Solids in the recirculating > water? If yes, is it controlled by a TDS sensor & controller?**** > > **6. **Does the recirc water go through a periodic purge cycle or > does it continue to circulate and water is replenished only when water > level in the basin drops?**** > > ** ** > > ** ** > > ** ** > > Rizik Michael, PE**** > > Principal**** > > Integrated Engineering Services**** > > Office: +408 261 3500, Ext. 201**** > > Cell: +408 718 0927**** > > ** ** > > ** ** > > *From:* labnetwork-bounces at mtl.mit.edu [mailto: > labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Robert Pollina > *Sent:* Wednesday, November 21, 2012 5:32 AM > *To:* labnetwork at mtl.mit.edu > *Subject:* [labnetwork] Requesting expertise/ experience with Scrubber > by-products in Fab.**** > > ** ** > > Good morning,**** > > ** ** > > I maintain the exhaust Scrubbers serving our wet-benches and fumehoods > here at the Nanofabrication Lab at the University of Michigan.**** > > Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide > solution is sprayed over a "whiffle-ball-like" material, and a favorable PH > is reached before the air is vented to atmosphere. The NaOH solution is > collected in a lower tank and recirculated to the spray heads. PH sensors > and Conductivity sensors call for more NaOH and city supplied fresh water > as needed.**** > > ** ** > > Problem: Large amounts of Fusarium , Negative rod and Rototurula > bacterias and fungi are created in the tank and must be removed to keep the > Scrubber operating properly. This by-product is removed almost daily, often > exceeding five gallons of concentrated solution.**** > > ** ** > > I'm hoping someone has experience with this same equipment and unwanted > Fusarium growth.**** > > How do we better control production of this by-product? What are the > proper safety procedures for maintenance staff?**** > > Are there other issues I am not aware of concerning this equipment, its > operation, maintenance and safety? **** > > ** ** > > Any assistance in this matter would be greatly appreciated.**** > > ** ** > > Robert Pollina**** > > University of Michigan**** > > Electrical Engineering and Computer Science**** > > Nanofabrication lab**** > -------------- next part -------------- An HTML attachment was scrubbed... URL: From kuhn1 at purdue.edu Tue Nov 27 16:31:42 2012 From: kuhn1 at purdue.edu (Kuhn, Jeffrey G) Date: Tue, 27 Nov 2012 21:31:42 +0000 Subject: [labnetwork] Fwd: Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> Message-ID: <06C167B22748364D85BCA1AA812FDA1A071783BB@WPVEXCMBX02.purdue.lcl> Robert, Based on your description of the airstream entering your scrubber, you should not have this problem - but obviously you do. I have a few questions and comments: * Your conductivity setpoint of 5000 uS concerns me for two reasons: o Assuming your make-up water conductivity is around 750 uS (typical for the Midwest), then you are running between six and seven cycles of concentration. That creates a lot of nutrients in the scrubber sump that bacteria can use to grow and multiply. The 7.5 to 9.5 pH you mention is a good operating range, but is also ideal for bacteria growth under those conditions. o If you are using high-hardness potable water for sump make-up (again, typical for the Midwest), then you will almost certainly create scaling on the scrubber packing as the calcium and magnesium precipitate out. This scale will eventually decrease the airflow through the packing by clogging the air paths and will result in a gradual increase in your exhaust fan speed as it tries to maintain your static pressure requirements. * My biggest curiosity lies in where the bacteria are coming from. Are there any BSL hoods tied into the scrubber, or are there any other biological agents that could be "seeding" the sump? * Is there any way that free acids, bases, etc. could be getting into the sump? Typically, the small amount of fumes from lab hoods should not cause a rapid change in pH or conductivity. * Is your pH and conductivity instrumentation calibrated routinely? Conductivity instruments tend to be relatively stable but pH instrumentation should be calibrated monthly - even more often if history indicates that it is necessary. pH electrodes should be replaced at least annually. * When you drain and refill your sump, what conductivity and pH numbers do you see initially and how rapidly do they change? * Are you certain that the scrubber is of sufficient size to handle the load (CFM, static pressure, face velocity, etc)? I'd like to make the following recommendations as a starting point: * Measure the conductivity of your make-up water, then set your blow down to maintain the sump at 3X that value initially. Run that way for a while and see how it impacts the problem. * Verify that your pH and conductivity instrumentation has been calibrated and replace the pH sensor if it has aged beyond a year or so. * Audit your system for the possible introduction of liquids or other materials from sources other than the fume hoods. * If you do data collection through Siemens, Johnson Controls, etc., trend the fan operation to see if it is speeding up over time with no additional demands being placed on the exhaust (an indication that fouling is occurring). If you try these things, please let us know if there are any improvements. Good luck! Jeff Kuhn Facility Engineer Birck Nanotechnology Center Purdue University 1205 W. State St. West Lafayette, IN 47907 Ph: (765) 496-8329 Fax: (765) 496-2018 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Robert Pollina Sent: Tuesday, November 27, 2012 7:37 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Fwd: Requesting expertise/ experience with Scrubber by-products in Fab. Struggling with Scrubber equipment and sending e-mails! Hope you saw this e-mail Michael and Jeff. ---------- Forwarded message ---------- From: Robert Pollina > Date: Mon, Nov 26, 2012 at 7:50 AM Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. To: Rizik > Michael, Thanks for the reply. I will provide some details of our operation. The five gallons of by-product I mentioned refers to a yellow-brown skin of Fusarium fungus and Negative Rod bacteria that forms on the surface of the recirculating tank. This material forms, grows and clogs the spray heads and pumps in the system. This material is removed by hand each day. The ph of the water in the recirculating tank is maintained between 7.5 and 9.5. The ph is controlled with a ph sensor in the tank and an automated Sodium Hydroxide (50% solution) feed pump system. A constant flow of fresh "city provided" water is maintained at 1/2 gallon per minute to make up for evaporation. We use this Scrubber system to scrub the acidic fume hood exhaust air from our labs. A conductivity sensor helps to maintain a solution that can efficiently deliver the desired result. A manual "blow-down" valve adds fresh water to the system while ejecting old tank water to the drain to assist in maintaining a conductivity reading below 5000u. The Scrubber tank is completely drained and refilled each week as total dissolved solids always exceeds the ability for a quick blow-down to lower conductivity to a good level after 5-7 days of lab operation. An in-line strainer collects the same material and is cleaned daily. I hope this furthers your understanding of our equipment (Harrington Scrubber) and procedures. Looking forward to hearing from you, let me know if more info is needed -Robert. On Sun, Nov 25, 2012 at 9:44 AM, Rizik > wrote: Please try to answer the following questions before we provide our recommendation: 1. Daily removal of 5-gallons of concentrated solution - Do you mean caustic solution? If yes, what is the concentration? 2. Is NaOH injection to the recirculating water stream being controlled by a pH Controller to maintained a predetermined pH level? 3. What are you trying to scrub? 4. What is the makeup water flow rate? 5. Doe you control Total Dissolved Solids in the recirculating water? If yes, is it controlled by a TDS sensor & controller? 6. Does the recirc water go through a periodic purge cycle or does it continue to circulate and water is replenished only when water level in the basin drops? Rizik Michael, PE Principal Integrated Engineering Services Office: +408 261 3500, Ext. 201 Cell: +408 718 0927 From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Robert Pollina Sent: Wednesday, November 21, 2012 5:32 AM To: labnetwork at mtl.mit.edu Subject: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab. Good morning, I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan. Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide solution is sprayed over a "whiffle-ball-like" material, and a favorable PH is reached before the air is vented to atmosphere. The NaOH solution is collected in a lower tank and recirculated to the spray heads. PH sensors and Conductivity sensors call for more NaOH and city supplied fresh water as needed. Problem: Large amounts of Fusarium , Negative rod and Rototurula bacterias and fungi are created in the tank and must be removed to keep the Scrubber operating properly. This by-product is removed almost daily, often exceeding five gallons of concentrated solution. I'm hoping someone has experience with this same equipment and unwanted Fusarium growth. How do we better control production of this by-product? What are the proper safety procedures for maintenance staff? Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? Any assistance in this matter would be greatly appreciated. Robert Pollina University of Michigan Electrical Engineering and Computer Science Nanofabrication lab -------------- next part -------------- An HTML attachment was scrubbed... URL: From rpollina at umich.edu Wed Nov 28 07:24:26 2012 From: rpollina at umich.edu (Robert Pollina) Date: Wed, 28 Nov 2012 07:24:26 -0500 Subject: [labnetwork] Fwd: Requesting expertise/ experience with Scrubber by-products in Fab. In-Reply-To: <06C167B22748364D85BCA1AA812FDA1A071783BB@WPVEXCMBX02.purdue.lcl> References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> <06C167B22748364D85BCA1AA812FDA1A071783BB@WPVEXCMBX02.purdue.lcl> Message-ID: Jeff, Thank you so much for the comments/ suggestions. I'm considering every suggestion made. I agree our make-up water is the first place to begin. Although I test and calibrate ph sensors monthly it has been over a year since they were installed, I'll order new sensors today. I'm searching for fumehood contaminents and other potential problems up-stream of our Scrubber that may be "seeding" the sump tank. I will monitor the initial and operating conductivity of our sump water. I am looking into retrofitting our system to use softened water instead of city-water. The "whiffle-ball" media is clean and functioning properly, mist screens are clean and unobstructed. I will purchase a biocide as suggested. Thanks again, I'll post an update to Labnetwork and let you know how it goes. -Robert On Tue, Nov 27, 2012 at 4:31 PM, Kuhn, Jeffrey G wrote: > Robert,**** > > ** ** > > Based on your description of the airstream entering your scrubber, you > should not have this problem - but obviously you do. I have a few questions > and comments:**** > > ** ** > > **? **Your conductivity setpoint of 5000 uS concerns me for two > reasons:**** > > **o **Assuming your make-up water conductivity is around 750 uS > (typical for the Midwest), then you are running between six and seven > cycles of concentration. That creates a lot of nutrients in the scrubber > sump that bacteria can use to grow and multiply. The 7.5 to 9.5 pH you > mention is a good operating range, but is also ideal for bacteria growth > under those conditions.**** > > **o **If you are using high-hardness potable water for sump make-up > (again, typical for the Midwest), then you will almost certainly create > scaling on the scrubber packing as the calcium and magnesium precipitate > out. This scale will eventually decrease the airflow through the packing by > clogging the air paths and will result in a gradual increase in your > exhaust fan speed as it tries to maintain your static pressure > requirements. **** > > **? **My biggest curiosity lies in where the bacteria are coming > from. Are there any BSL hoods tied into the scrubber, or are there any > other biological agents that could be ?seeding? the sump?**** > > **? **Is there any way that free acids, bases, etc. could be > getting into the sump? Typically, the small amount of fumes from lab hoods > should not cause a rapid change in pH or conductivity.**** > > **? **Is your pH and conductivity instrumentation calibrated > routinely? Conductivity instruments tend to be relatively stable but pH > instrumentation should be calibrated monthly ? even more often if history > indicates that it is necessary. pH electrodes should be replaced at least > annually.**** > > **? **When you drain and refill your sump, what conductivity and > pH numbers do you see initially and how rapidly do they change?**** > > **? **Are you certain that the scrubber is of sufficient size to > handle the load (CFM, static pressure, face velocity, etc)? **** > > ** ** > > I?d like to make the following recommendations as a starting point:**** > > ** ** > > **? **Measure the conductivity of your make-up water, then set > your blow down to maintain the sump at 3X that value initially. Run that > way for a while and see how it impacts the problem.**** > > **? **Verify that your pH and conductivity instrumentation has > been calibrated and replace the pH sensor if it has aged beyond a year or > so.**** > > **? **Audit your system for the possible introduction of liquids > or other materials from sources other than the fume hoods. **** > > **? **If you do data collection through Siemens, Johnson > Controls, etc., trend the fan operation to see if it is speeding up over > time with no additional demands being placed on the exhaust (an indication > that fouling is occurring).**** > > ** ** > > If you try these things, please let us know if there are any improvements. > **** > > ** ** > > Good luck!**** > > ** ** > > Jeff Kuhn**** > > Facility Engineer**** > > Birck Nanotechnology Center**** > > Purdue University**** > > 1205 W. State St.**** > > West Lafayette, IN 47907**** > > Ph: (765) 496-8329**** > > Fax: (765) 496-2018**** > > ** ** > > ** ** > > ** ** > > *From:* labnetwork-bounces at mtl.mit.edu [mailto: > labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Robert Pollina > *Sent:* Tuesday, November 27, 2012 7:37 AM > *To:* labnetwork at mtl.mit.edu > *Subject:* [labnetwork] Fwd: Requesting expertise/ experience with > Scrubber by-products in Fab.**** > > ** ** > > Struggling with Scrubber equipment and sending e-mails! Hope you saw this > e-mail Michael and Jeff.**** > > ---------- Forwarded message ---------- > From: *Robert Pollina* > Date: Mon, Nov 26, 2012 at 7:50 AM > Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber > by-products in Fab. > To: Rizik > > > Michael,**** > > Thanks for the reply.**** > > I will provide some details of our operation.**** > > The five gallons of by-product I mentioned refers to a yellow-brown skin > of Fusarium fungus and Negative Rod bacteria that forms on the surface of > the recirculating tank. This material forms, grows and clogs the spray > heads and pumps in the system. This material is removed by hand each day. > **** > > The ph of the water in the recirculating tank is maintained between 7.5 > and 9.5. The ph is controlled with a ph sensor in the tank and an > automated Sodium Hydroxide (50% solution) feed pump system. A constant > flow of fresh "city provided" water is maintained at 1/2 gallon per minute > to make up for evaporation.**** > > We use this Scrubber system to scrub the acidic fume hood exhaust air > from our labs. **** > > A conductivity sensor helps to maintain a solution that can efficiently > deliver the desired result.**** > > A manual "blow-down" valve adds fresh water to the system while ejecting > old tank water to the drain to assist in maintaining a conductivity reading > below 5000u.**** > > The Scrubber tank is completely drained and refilled each week as total > dissolved solids always exceeds the ability for a quick blow-down to lower > conductivity to a good level after 5-7 days of lab operation. **** > > An in-line strainer collects the same material and is cleaned daily.**** > > I hope this furthers your understanding of our equipment (Harrington > Scrubber) and procedures. Looking forward to hearing from you, let me > know if more info is needed**** > > -Robert.**** > > ** ** > > On Sun, Nov 25, 2012 at 9:44 AM, Rizik wrote:**** > > Please try to answer the following questions before we provide our > recommendation:**** > > **** > > 1. Daily removal of 5-gallons of concentrated solution - Do you mean > caustic solution? If yes, what is the concentration?**** > > 2. Is NaOH injection to the recirculating water stream being > controlled by a pH Controller to maintained a predetermined pH level?**** > > 3. What are you trying to scrub?**** > > 4. What is the makeup water flow rate?**** > > 5. Doe you control Total Dissolved Solids in the recirculating > water? If yes, is it controlled by a TDS sensor & controller?**** > > 6. Does the recirc water go through a periodic purge cycle or does > it continue to circulate and water is replenished only when water level in > the basin drops?**** > > **** > > **** > > **** > > Rizik Michael, PE**** > > Principal**** > > Integrated Engineering Services**** > > Office: +408 261 3500, Ext. 201**** > > Cell: +408 718 0927**** > > **** > > **** > > *From:* labnetwork-bounces at mtl.mit.edu [mailto: > labnetwork-bounces at mtl.mit.edu] *On Behalf Of *Robert Pollina > *Sent:* Wednesday, November 21, 2012 5:32 AM > *To:* labnetwork at mtl.mit.edu > *Subject:* [labnetwork] Requesting expertise/ experience with Scrubber > by-products in Fab.**** > > **** > > Good morning,**** > > **** > > I maintain the exhaust Scrubbers serving our wet-benches and fumehoods > here at the Nanofabrication Lab at the University of Michigan.**** > > Exhaust air passes through our Harrington Scrubber where Sodium Hydroxide > solution is sprayed over a "whiffle-ball-like" material, and a favorable PH > is reached before the air is vented to atmosphere. The NaOH solution is > collected in a lower tank and recirculated to the spray heads. PH sensors > and Conductivity sensors call for more NaOH and city supplied fresh water > as needed.**** > > **** > > Problem: Large amounts of Fusarium , Negative rod and Rototurula > bacterias and fungi are created in the tank and must be removed to keep the > Scrubber operating properly. This by-product is removed almost daily, often > exceeding five gallons of concentrated solution.**** > > **** > > I'm hoping someone has experience with this same equipment and unwanted > Fusarium growth.**** > > How do we better control production of this by-product? What are the > proper safety procedures for maintenance staff?**** > > Are there other issues I am not aware of concerning this equipment, its > operation, maintenance and safety? **** > > **** > > Any assistance in this matter would be greatly appreciated.**** > > **** > > Robert Pollina**** > > University of Michigan**** > > Electrical Engineering and Computer Science**** > > Nanofabrication lab**** > > ** ** > > ** ** > -------------- next part -------------- An HTML attachment was scrubbed... URL: From ocola at anl.gov Fri Nov 30 12:29:40 2012 From: ocola at anl.gov (Leonidas Ocola) Date: Fri, 30 Nov 2012 11:29:40 -0600 Subject: [labnetwork] question ... In-Reply-To: References: <0b6d01cdcb1b$5ea130b0$1be39210$@com> <06C167B22748364D85BCA1AA812FDA1A071783BB@WPVEXCMBX02.purdue.lcl> Message-ID: <50B8ED04.6010301@anl.gov> Dear List, When does it make sense to just use a point of use scrubber for a particularly noxious tool or when to install a "capture it all" scrubber at the end of a facility exhaust? Just curious. Thanks Leo -- Leonidas E Ocola, PhD Center for Nanoscale Materials Argonnne National Laboratory Bldg 440, Rm A129 9700 South Cass Avenue, Argonne, IL 60439 Ph: 630-252-6613 Fax: 630-252-5739