Page 293 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Mechanical Separations 263

If inlet vane is formed with inlet connection: Areas: Gas Velocity Velocity Head*
-----
Inlet duct: 1.398 sq ft 47.7 ft/sec 0.50 in. water
K = 7.5
Cyclone inlet: 2.0 sq ft 33.33 ft/sec 0.25 in. water
Cyclone exit duct: 3.14 sq ft 21.2 ft/sec 0.10 in. water
Example 4-6: Cyclone System Pressure Drop
02
8 Vclocity head, inches water= V /(16) (10 6), Vr, = ft/min
A cyclone system is to be installed as a part of a bagging Friction Loss CD to ®
operation. The unit is shown in Figure 4-48. Determine
the head required for purchase of the fan. The conditions NRc = 398,000 f = 0.0038
are:
Air volume: 4000 cu ft per min of air at 70°F 4fL 4 (.0038) (18)
No. Vel. I-Id. 0.204vel. head
Air density: 0.075 lb/ cu ft D (16/12)

100

90
�� __ :_=�-t---=-�==-; _ _J_�
80
_L__ _ __ L _ __ J_ ; __ -� __ _ I
70 _ -C _
>- l
u I '
z '. J__ _L_ --- 1----+- -
w
u 60 ---j-- --
.:;:: I I : I I I : '
..... -- ----l------t---------------1--_;____
w 50 --- . -�----<
.... . ' _j_ I I :
z
�
�
w �o
� � ��
u -- --+�:-=�. -----_ - ---±- -TI-Cl----:-- ,.[J , .-l-V-. -C?,_ :-C ITY _:_------i-<
"' ... --+ -
w
30 ..
_-r_r---+---- ---- -
20 1
10 ------->----+--
PARTICLE SIZE-MICRONS
0
c 5 10 15 10 15 30 35 40
Figure 4-46. General efficiency curves, applies specifically to helical entry cyclone dust separators. Courtesy of The Ducon Co.
100 -
-
90
I
80 v """
f-
z 70 ./ -
ul »>
u
a: /
"'60 ---
IL I /
I l
>- /
li 50 /
"' u I / -\...--- --- I ---'----· I
;;:
"- 40 v . � �-
ul ' i
z / .. --
0 1� i
;:: / I i
td 30 v - ---- i COLLECTION EFFICIENCY
� / I I I - -- -�-- __ VS
TERMNAL VELOCiTY
U 2!> v --:------ -- -- - TT_T_
I I
20
.3 .4 .!I .e :1.s 1.0 1.5 2.0 3.0 4.0 50 6.0 W 8.0 10 15 20 30 40 50 60 70 80 IOO 150 «>0 300 400
TERMINAL VELOCITY - INCHES PER MINUTE
Figure 4-47. General efficiency curve applies specifically to involute entry cyclone dust separators. Courtesy of American Blower Div., Amer-
ican Radiator and Standard Sanitary Corp.