Struggling with Scrubber equipment and sending e-mails! Hope you saw this e-mail Michael and Jeff.<br><br><div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Robert Pollina</b> <span dir="ltr"><<a href="mailto:rpollina@umich.edu">rpollina@umich.edu</a>></span><br>
Date: Mon, Nov 26, 2012 at 7:50 AM<br>Subject: Re: [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab.<br>To: Rizik <<a href="mailto:rizik@intengr.com">rizik@intengr.com</a>><br><br><br>Michael,<div>
Thanks for the reply.</div><div>I will provide some details of our operation.</div><div> 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.</div>
<div> 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.</div>
<div> We use this Scrubber system to scrub the acidic fume hood exhaust air from our labs. </div><div> A conductivity sensor helps to maintain a solution that can efficiently deliver the desired result.</div><div> 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.</div>
<div>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. </div>
<div>
An in-line strainer collects the same material and is cleaned daily.</div><div> 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</div>
<span class="HOEnZb"><font color="#888888">
</font></span><div><span class="HOEnZb"><font color="#888888">-Robert.</font></span><div><div class="h5"><br><br><div class="gmail_quote">On Sun, Nov 25, 2012 at 9:44 AM, Rizik <span dir="ltr"><<a href="mailto:rizik@intengr.com" target="_blank">rizik@intengr.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Please try to answer the following questions before we provide our recommendation:<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>1.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Daily removal of 5-gallons of concentrated solution - Do you mean caustic solution? If yes, what is the concentration?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>2.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Is NaOH injection to the recirculating water stream being controlled by a pH Controller to maintained a predetermined pH level?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>3.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What are you trying to scrub?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>4.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What is the makeup water flow rate?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>5.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Doe you control Total Dissolved Solids in the recirculating water? If yes, is it controlled by a TDS sensor & controller?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>6.<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span dir="LTR"></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">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?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Rizik Michael, PE<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Principal<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Integrated Engineering Services<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Office: +408 261 3500, Ext. 201<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Cell: +408 718 0927<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a> [mailto:<a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a>] <b>On Behalf Of </b>Robert Pollina<br>
<b>Sent:</b> Wednesday, November 21, 2012 5:32 AM<br><b>To:</b> <a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a><br><b>Subject:</b> [labnetwork] Requesting expertise/ experience with Scrubber by-products in Fab.<u></u><u></u></span></p>
</div><div><div><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Good morning,<u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> I maintain the exhaust Scrubbers serving our wet-benches and fumehoods here at the Nanofabrication Lab at the University of Michigan.<u></u><u></u></p>
</div><div><p class="MsoNormal">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.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> 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.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> I'm hoping someone has experience with this same equipment and unwanted Fusarium growth.<u></u><u></u></p></div><div><p class="MsoNormal">
How do we better control production of this by-product? What are the proper safety procedures for maintenance staff?<u></u><u></u></p></div><div><p class="MsoNormal">Are there other issues I am not aware of concerning this equipment, its operation, maintenance and safety? <u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> Any assistance in this matter would be greatly appreciated.<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div>
<p class="MsoNormal">Robert Pollina<u></u><u></u></p></div><div><p class="MsoNormal">University of Michigan<u></u><u></u></p></div><div><p class="MsoNormal">Electrical Engineering and Computer Science<u></u><u></u></p></div>
<div><p class="MsoNormal">Nanofabrication lab<u></u><u></u></p></div></div></div></div></div></blockquote></div><br></div></div></div>
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