Page 257 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

Mechanical Separations 227

SIZE AND CHARACTERISTICS OF AIR-BORNE SOLIDS

DIMI. RATE OF
OF U.S. SCALE OF SETTLING
IN f P_M.
PAA- ST'D
FDA
TICU:S MESH SPHERES
••
MICRONS ATMOSPHERIC IMPURITIES SPEC. GRAV.1
AT 7Cf'F.
8000
w
6000 .; ,_ ,.. tl!iO
4000 I - .. .....
w
::I
en
0 z ... :
2000 s
-
.!..
0
10 16 z ;= .... u;
1000 ::: != � c 7!10
800 20 -- - -
-
600 - z - .... !i!i!i
....
400 64 ... � .. � � z
I
u
�
c
;;;;;
60 1" - - c ;":' ;
200 128 .. u -
z
100 IC :z: :,:: � cc IC
a.
Cl
100 150 >- u 0 !i!l 1
80 200 -· .. :.: -
-
60 250 w z � .., - :- ..... 14 A
40 32� >- � w >- ... Cl
�
0::
so;; ! - u - �
;:::
-·
20 c.::, u 0 .. ii: ;::.:;
;;;
a:
�
�
1000 CII w :I ..
:z:
10 :,: .!i92
8 = � - ..
6 - � ... ... "" � 14A
...
4 ;;;;; ... "5 = ·� a.
....
en ...
:z:
::I
0
v,
2 ... z 0:: v• ::E � en
::::;
...
"II
:E
u ci
....
w
0
-
I � 0... >- .... .... !:IC .007=
.6 - - - ... .... oo,=
11
PER HR .
. 8
-
.4 - -
m
i:
0 ... "' ... w \4"
::I
PER HR .
:E ::I z ""' �
::I
.2 c � - � "' I
..
I- Cl ::E o 00007=
.1
PER HR.
,..., - .... - - 4 0
...
....
...
w .... :. -
I w - � z � .... 1;;::; =-
t u w O .... � u � ... u -
;::: z: � � er
u
u
t.ll,y
en
; = c:z: ii: ... 5 a:i :;; �o -
.. ; � z ::. Q Cl) :E IC
.... �
Q.
0 -
.01 "' a: __, ::,,:: I- � - 0
- �
-
= -
� - - � - �- n
0 a: - �
w � " � c[ = - :-:
-- cc
- .... .... - :i ::;
:::i!i
v, ;:: � ... t:i ... :;:;:w u
a:
- :> c:;
.001 <( al IO
IT IS ASSUMED THAT THE PARTICLES ARE OF UNIFORM SPHERICAL SHAPE HAVING
SPECIFIC GRAVITY ONE AND THAT THE DUST CONCENTRATION IS 0.6 GRAINS PER
1000 CU. FT. OF AIR, THE AVERAGE OF METROPOLITAN DISTRICTS.
Figure 4-1A. Size and characteristics of air-borne solids. By permission, Hoffman Handy Engineering Data, Hoffman Air and Filtration Sys-
tems, Inc.
ticle size in the collector effluent. Where this line inter- A projection of this point of coliector effluent vertical-
sects the horizontal line marked 2.25 grains/cu ft, a verti- ly downward shows that a second high efficiency centrifu-
cal line through the point will indicate the effluent mean gal will be less than 50% efficient. A wet collector, fabric
particle size of 6.0 microns. arrester and electro-static precipitator will be not Jess than