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364 Lawrence K. Wang et al.

Table 8
Average Specific Heats of Vapors a
a
Average specific heat, C (Btu/scf-ºF)
Temp. p
(ºF) Air H O O N CO CO H CH C H C H
2 2 2 2 2 4 2 4 2 6
77 0.0180 0.0207 0.0181 0.0180 0.0180 0.0230 0.0178 0.0221 0.0270 0.0326
212 0.0180 0.0209 0.0183 0.0180 0.0180 0.0239 0.0179 0.0232 0.0293 0.0356
392 0.0181 0.0211 0.0186 0.0181 0.0181 0.0251 0.0180 0.0249 0.0324 0.0395
572 0.0183 0.0212 0.0188 0.0182 0.0183 0.0261 0.0180 0.0266 0.0353 0.0432
752 0.0185 0.0217 0.0191 0.0183 0.0184 0.0270 0.0180 0.0283 0.0379 0.0468
932 0.0187 0.0221 0.0194 0.0185 0.0186 0.0278 0.0181 0.0301 0.0403 0.0501
1112 0.0189 0.0224 0.0197 0.0187 0.0188 0.0286 0.0181 0.0317 0.0425 0.0532
1292 0.0191 0.0228 0.0199 0.0189 0.0190 0.0292 0.0182 0.0333 0.0445 0.0560
1472 0.0192 0.0232 0.0201 0.0190 0.0192 0.0298 0.0182 0.0348 0.0464 0.0587
1652 0.0194 0.0235 0.0203 0.0192 0.0194 0.0303 0.0183 0.0363 0.0481 0.0612
1832 0.0196 0.0239 0.0205 0.0194 0.0196 0.0308 0.0184 0.0376 0.0497 0.0635
2012 0.0198 0.0243 0.0207 0.0196 0.0198 0.0313 0.0185 0.0389 0.0512 0.0656
2192 0.0199 0.0246 0.0208 0.0197 0.0199 0.0317 0.0186 0.0400 0.0525 0.0676

Note: Average for the temperature interval 77ºF and the specified temperature.
a Based on 70ºF and 1 atm. To convert to Btu/lb-ºF basis, multiply by 392 and divide by the molecular
weight of the compound. To convert to Btu/lb-molºF, multiply by 392.
Source: ref. 4.

Q = Q + Q + Q
fg e f d
Q = 15,000 + 163 + 0
fg
Q = 15,200 scfm (rounded to three significant digits)
fg
2. The actual flue gas flow rate Q can be determined using Eq. (5).
fg,a
Q fg,a =15 200 1 800 460 537, ( [ , + ) ]
= 64,000 acfm

3. The combustion chamber volume V can then be calculated using Eq. (6).
c
V = ( [ 64 000 60 )0 75. ] ×1 05.
,
c
V =840 ft 3
c
The combustion chamber volume for the proposed thermal incinerator should therefore
3
have a value that is approx 840 ft .
Example 6

Discuss how the permit application for a thermal incinerator is evaluated.
Solution

Compare the calculated values and reported values using Table 9. The combustion volume
(V ) is calculated from flue gas flow rate (Q ) and Q is determined by emission stream
c fg fg