Page 348 - Air Pollution Control Engineering

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326 Lawrence K. Wang et al.

4. Determine Ref using Eq (11).
H = 239 000 Btu h
,
load
Ref = H load 12 000 (11)
,
,
Ref = 239 000 12 000
,
Ref = 20 tons
5. Determine Q using Eq. (12) and Table 2.
rec
HAP = HAP − HAP
con em om
,
,
HAP = . 0 06633 0
− .00663
con
HAP = . 0 0597 lb-mol min, from Eq. (4) and Example 2
con
MW =104 .2 lb lb-mol
HAP
Q rec = 60 × HAP con × MW HAP (12)
× .0597
Q = 60 0 ×104 .2
rec
Q rec = 373 lb h
After a condensation system is properly designed and sized, many main components
of the condensation system can be purchased from the manufacturers (20). One of the
condenser manufacturers or suppliers is Swenson Process Equipment, Inc. in Harvey,
IL (USA).
Example 4
Given the following information about a condenser system, determine the fan power
requirement, F :
p
1. Emission stream flow rate (Q ) = 2050 acfm
e,a
2. Condenser system pressure drop (P) = 5 in. H O
2
3. Condenser system operating hours per year (HRS) = 6000 h/yr
Solution
Determine F using Eq. (13):
p
F = 1.81 × 10 −4 (Q )(P)(HRS) (13)
p e,a
F = 1.81 × 10 −4 (2050)(5)(6000)
p
F = 11,100 kWh/h
p
NOMENCLATURE
2
A Condenser (heat exchanger) surface area (ft )
con
C Average specific heat of air for the temperature interval (T con − T )
o
p air
(Btu/lb-mol ºF)
C Average specific heat of the coolant over the temperature interval
p coolant
T to T (Btu/lb ºF)
cool,i cool,o
C Average specific heat of the HAP for the temperature interval (T −
p con
HAP
T ) (Btu/lb-mol ºF)
o
F Fan power requirement (kWh/yr)
p
H Enthalpy change associated with the condensed HAP (Btu/h)
con
H Condenser heat load (Btu/h)
load
H Enthalpy change associated with the noncondensible vapors (Btu/h)
noncon