Page 406 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

374 Applied Process Design for Chemical and Petrochemical Plants

Table 6-9 Table 6-10
Evacuation Factors for Single Stage Jet Evacuation Factors For Two Stage Non-Condensing
Ejectors

Final Suction Pressure Evacuation Factor,
Final Suction Pressure Evacuation In. Hg. Abs. E
In.Hg.Abs. Factor, E
0.5 0.48
10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 1.0 0.67
8 1.0 1.5 .•••.•..•.••...••••.......•••....• 0.81
2.0 0.92
6 1.5
2.5 .....•......................•..... 1.00
5 1.0 3.0 ..•.•.•••..••••........•.........• I.IO
4 1.3 *By permission, Worthington Corp. Bui. W-205-SlOA.

*By permission, Worthington Corp. Bulletin 'W-205-SlA.
Ejector Selection Procedure

Utility unit costs as well as any preference for maxi- As a guide, the following is a suggested procedure for rat-
mum opera.ting economy or minimum first cost should be ing and selecting an ejector system for vacuum operation.
stated if the manufacturer is to make a selection to best fit
the plant system and economics. 1. Determine vacuum required at the critical process
point in system.
2. Calculate pressure drop from this point to the
Tables 6-11, 6-12, 6-13, and 6-14 provide useful refer- process location of the suction flange of the first
ence data. stage ejector.

200 I I I -

150 I I t-::. is90_ - -
.__
et \-\OUn;..-
s,eo�.2--- - "'"-" - - -
-
,��- -
... 100 \ � (j::.,..,-r l _.__ ,_ - -
0
·- -
:::, 80 ...... - --3" -
0 1....,, 1--- - -
i- ....... -
::i:: . I,"' I r::l:J'"' 1.,.- ,_ ·- ..... -
... 60 . _ ....
cu i> I., ,� o·i.- i- ·-
i.-
0. 50 1./v i..,.,,�o l,...,, i.- i.- i.- ....... -
...
t-r v
- 40 l/ i- ...... 1....... ._�oo L.,.,-,_ ,_ i.- i.- - .__ i..- ....... i- i- i-
cu
I
_.a.-
O
,,
,
i., GO
:::,
i.-
-�
1.,.-
- v ,, v ., � � v 0tOO _ i.- i.- i.- i.- i- i..- ,_
,_
i.-
I/
:E 30
v
I
211
0
I/ v
en I/ I/ v I,; vi.,.,,i...- .so 0"' i.- i.- -
.
.Q 20 v .... l,...,, .... i.- i.-
I/ 1./ i> .., L,..,- I i.- i.- _.._ i..- ....- i- i-
IC 15 v / 7..00- i.- ....--
;§ i> I' L.,.,- i....,,,- I i.- i.- i.- .._ .._
l/ i> � (.,..,,,' v .... ,1oi.- ....- i.- i.- i..i- i.- ·- ....- i- i.- i-
i.-
>,
- ... 10 ,; I/ � - i- ,-� 40-
IC 8 ,, . ..... , _ ... _,,o '--"
c.. v L. .....
IC
u ,/ .., ..... , i.,., _L.--
6 v i.,.,
5 l/ ... I' L..,.,
.6 .8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2
Ejector Suction Pressure, Inches Hg. Abs.
Figure 6-27A. Size ejector for 90 psig steam consumption, two-stage, non-condensing 0.6"-3.0" Hg abs. By permission, Worthington Corp.