Page 440 - Air Pollution Control Engineering

10_chap_wang.qxd 05/05/2004 5:10 pm Page 412
412 Lawrence K.Wang et al.

Solution

Step 1
Use Eq. (3) to calculate the amount of carbon required (C ):
req
C = (M θ [1 + (ND/NA)])/W (3)
req HAP ad c
C = lb carbon
req
The carbon required per vessel (C' ) is determined by dividing carbon required (C ) by
req req
the number of beds adsorbing (NA).
C' = C /NA
req req
Step 2

If the HAP inlet loading (M ) is not given, use Eq. (4) to calculate it.
HAP
M = 6.0 × 10 −5 (HAP )(Q )(D ) (4)
HAP e e HAP
M = lb/hr
HAP
where

D = PM/RT (9)
HAP
D = lb/ft 3
HAP
Step 3
The vessel diameter, D vessel length, L , and the vessel size, S, are obtained using Eq.
v’ v
(5), (7), and (8), respectively.
D = 0.127 C' U /Q' (5)
v req e e,a
where

Q = Q (T + 460)/537 (7)
e,a e e
Q = acfm
e,a
The emission stream flow rate per adsorbing bed (Q' ) is obtained by dividing the HAP
e,a
emission stream by the number of beds adsorbing (NA)
Q' = Q /NA
e,a e,a
Q' = acfm/bed
e,a
D = ft
v
2
L = 7.87 (Q´ /U ) /C (6)
v e,a e req
L = ft
v
S =π D (L + D /2) (8)
v v v
S = ft 2

Example 3
Design a two-bed regenerative carbon adsorption system for removal of HAP from a
gaseous emission stream. Given data are as follows: