[labnetwork] question ...

[Rizik]

In addition, your local/regional air quality management district should have
a limit on the quantity of toxic, highly toxic and particulate discharged
into the atmosphere. You might want to consult with the local district about
the maximum allowable discharge limits. 

I agree with Michael about the reactivity and byproducts. In case you are
using gases with corrosive residual byproducts where some of these gases are
released from the tool un-reacted, such gases need to be locally abated. The
process could either be a wet scrubber, a thermal-wet abatement system or a
dry scrub system. The cost of these systems ranges between $55K for a single
canister dry scrub system to up to $125K for a thermal wet point of use
scrubber. If you are abating ozone depleting gases along with other
toxic/corrosive gases, then the cost could be as high as $150K. Each option
brings to the table other challenges that need to be met. Depending on your
current facility infrastructure set up you might be able to favor one over
the other.

Regards

Rizik Michael, PE
Principal
Integrated Engineering Services
Office: +408 261 3500, Ext. 201
Cell:      +408 718 0927



-----Original Message-----
From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu]
On Behalf Of Michael Khbeis
Sent: Saturday, December 01, 2012 5:32 AM
To: Leonidas Ocola
Cc: labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] question ...

Leonidas,

I would say it is dependent on the reactivity of the byproduct.  For
pyrophorics we "scrub" at the point of use with a gas reactor column.  For
acids we just collect at the main scrubber.  If there was something that
would be potentially reactive with other byproducts, you may be better off
with the local scrubber, but these are very expensive.  You also need to
consider the dilution factor in the exhaust stream.  If you have a large
volume of exhaust, say from numerous wet benches, this will dilute the
shared exhaust so consider the volume and rate of byproduct being produced
compared to the total exhaust volume/flow.

Dr. Michael Khbeis
Associate Director
Microfabrication Facility (MFF)
University of Washington
Fluke Hall, Box 352143
(O) 206.543.5101
(C) 443.254.5192
khbeis at uw.edu



On Nov 30, 2012, at 9:29 AM, Leonidas Ocola wrote:

> 
> 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
> 
> 
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