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Tom,
There are really three
parts to the formula I used for fugitives. I just combined them all
into one, which makes the formula a little long. The breakdown is
below. This could get pretty tricky with several control devices in
different configurations. This is the kind of thing we had to use stream
tracing algorithms for in RAPIDS 2.x, and even those were limited
to certain basic configurations. It also lead to terms like "mass flow to
next device" and "downstream discharge".
Per our discussion on
Monday, which was very helpful, I think we can avoid the stream tracing issues
by using the control system approach. NEI and the new EIS control
collection both use this approach in slightly different ways. With RAPIDS,
we will have to be a little bit more strict in our definitions while still
accomodating those other systems. We should discuss this in the meeting on
Tuesday.
1) Fugitive from first
control, using first capture efficiency:
F1 = Total Emission *
(1-CAP1/100)
2) Controlled emission
from first control (emissions going to next control
device):
C = Total Emission * (CAP1/100)
* (1-CEF1/100)
-
Notice this is just the first part of Cong's formula for controlled
emissions.
3) Second fugitive is
calculated on C, using second capture
efficiency:
F2 = C *
(1-CAP2/100)
Total Fugitive Emission
= F1 + F2
So, we end up with these
two equations (for two controls in series):
Controlled
Emission = Total Emission * (CAP1/100) * (1-CEF1/100) * (CAP2/100) *
(1-CEF2/100)
Fugitive Emission = [Total Emission * (1-CAP1/100)]
+
[Total
Emission * (CAP1/100) * (1-CEF1/100) * (1-CAP2/100)]
Mark
From: Tom Velalis [mailto:tom.velalis@epa.state.oh.us] Sent: Friday, May 18, 2007 8:14 AM To: 'Airtoxics'; Mark Young Subject: RE: Control Device Information What about a using the following equation to estimate the fugitives if
the
total emissions are known:
Fugitive Emissions= (Total Emissions)- (Controlled Emissions) where: Total Emissions = Controlled +fugitives
The above equation will give you the same answer irrespective of the order. I could not quite follow your logic in your formula.
Tom >>> "Mark Young" <ravenhunter@qwest.net> 5/17/2007 6:01 PM >>> Cong,
I think the order does matter.
Depending on the order of capture, the fugitives and can be
different.
Your calculation is correct for the controlled
emissions. You'll always get the same answer, independent of the
order. But change the order for the fugitive calculations, and you'll see
that you get different answers.
Fugitive Emission = [Total Emission * (1-CAP1/100)]
+
[Total
Emission * (CAP1/100) * (1-CEF1/100) * (1-CAP2/100)]
I think I got that right...
Mark
From: owner-airtoxics@great-lakes.net [mailto:owner-airtoxics@great-lakes.net] On Behalf Of Doan, Congtru (ENE) Sent: Thursday, May 17, 2007 2:56 PM To: Mark Young; Airtoxics Subject: RE: Control Device Information Mark, For a system of two control devices
of the same pollutant: C1: Capture efficiency CAP1,
Control efficiency CEF1 C2: Capture efficiency CAP2,
Control efficiency CEF2 Controlled Emission = Total
Emission * (CAP1/100) * (1-CEF1/100) * (CAP2/100) *
(1-CEF2/100) Does it matter if which control
device captures first? Even if both CAP1 and CAP2 are less than
100%. Cong, |