Page 305 - Materials Chemistry, Second Edition

288 Practical Design Calculations for Groundwater and Soil Remediation

0.28

0.27
Cp (Btu/lb- °F) 0.26

0.25

0.24
0 500 1000 1500 2000 2500
Temperature (°F)

FIGURE 7.1
Specific heat of air versus temperature.

(c) The heat content of the waste gas is 55.6 Btu/lb, as determined in
Example 7.7.
(d) The flow rate of the supplementary fuel can be estimated by
using Equation (7.19) as:

DQ w [C p (1.1T c −T he − 0.1 )T r − H w ]
w
Q sf =
[
DH sf − 1.1 CT −T r )]
p
sf
( c
−
−
(0.0739)(200){(0.266)[1.1(1,800)1,280 − 0.1(77)] 55.6}
=
−
(0.0408){21,600 − 1.1[(0.266)(1,800 77)}
= 2.21 scfm

7.3.6 Volume of the Combustion Chamber
The total influent to an incinerator is the sum of the waste air, dilution air
(and/or the auxiliary air), and the supplementary fuel, and it can be deter-
mined by the following equation:

Q inf = Q w + Q d + Q sf (7.21)

where Q = the total influent flow rate, scfm.
inf
In most cases, one can assume that the flow rate of the combined gas
stream, Q , entering the combustion chamber is approximately equal to the
inf
flue gas leaving the combustion chamber at standard conditions, Q . The
fg
volume change across the incineration chamber, due to combustion of VOC
and supplementary fuel, is assumed to be small. This is especially true for
dilute VOC streams from soil/groundwater remediation.