| |
Size Liquid Motive for Exhausting Gases
|
|
|
Exhausting is a continuous operation of removing
gases at a constant suction pressure. The units are sized
based on a desired flow rate of gas through the eductor.
|
| |
| Step 1 |
| Before beginning to do the actual sizing, convert
all pressure and flow to the units used in the sizing table. (If
sizing is done regularly with other units, request a special sizing
table from your representative.) |
| |
| Step 2 |
| First find the value that is equal to or greater
than your system back pressure in the Outlet Pressure (Po) column.
After locating the correct value on the sizing table, use
this section of the table to size the unit. |
| |
| Step 3 |
| Locate the pressure that is equal to or higher than
your desired suction pressure (Ps) for the outlet pressure found
in Step 2. If the pressure is between two values on the sizing
table, you can interpolate between them. If you don't wish to interpolate,
the higher pressure will give a conservative estimate. |
| |
| Step 4 |
| In the row for suction pressure (Ps), locate the
column where the motive pressure (Pm) is equal to your motive pressure
in the flowing condition. If the pressure is between two levels
on the sizing table, you can interpolate between the values.
If you don't wish to interpolate, the lower pressure will give
a conservative estimate. |
| |
| Step 5 |
|
Divide your desired flow (Qs) rate by the flow
rate of each model. This will give you a desired Sizing Factor
(S.E) for each model. Pick a unit with a S.F. that is equal to
or larger than the one calculated above.
Generally, the model with a larger suction capacity will be
the more efficient unit. To calculate the actual gas flow,
multiply the S.F. of the selected model by the suction flow
(Qs) of the model in the table.
|
| |
| Step 6 |
| Calculate the amount of water required to operate
the eductor by multiplying the GPM in the Motive Flow (Qm)
row by the S.F. of the unit selected. |
| |
| Note 1: |
| In many cases, the capacity of the MLE and ML units
are close. Both should be sized to find the proper unit for the
application. |
| |
| Note 2: |
| When using liquids to pump gases, the eductor acts
as a volume displacing device. Therefore, the weight of the
gas has only minimal effect on the performance of the eductor. |
| |
| |
|
Outlet
|
Suction
|
ML,
MLE Liquids Exhausting Gases
|
1-1/2" Unit
|
|
Pressure
|
Pressure,
Ps
|
Motive
Pressure - Prn (PSIG)
|
|
|
|
20
|
40
|
60
|
80
|
100
|
140
|
200
|
250
|
|
Po
(PSIG)
|
(In
Hg Abs)
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
|
|
30
|
8.4
|
7.3
|
10.5
|
9.4
|
13.6
|
12.6
|
14.7
|
13.6
|
18.9
|
14.7
|
19.9
|
18.9
|
22.0
|
19.9
|
30.8
|
21.9
|
|
|
25
|
1.7
|
3.1
|
3.7
|
5.8
|
6.0
|
8.4
|
8.9
|
10.7
|
10.4
|
12.0
|
13.2
|
15.0
|
17.5
|
18.1
|
24.5
|
19.9
|
|
|
20
|
0.9
|
1.7
|
2.0
|
3.7
|
3.5
|
5.9
|
5.2
|
8.1
|
6.5
|
9.2
|
9.7
|
11.8
|
13.6
|
14.7
|
19.0
|
16.2
|
|
0
|
15
|
0.5
|
0.8
|
1.2
|
2.5
|
1.9
|
3.9
|
1.9
|
5.8
|
3.9
|
6.6
|
5.5
|
8.8
|
9.2
|
11.0
|
12.9
|
12.1
|
|
|
10
|
|
|
0.9
|
1.3
|
0.9
|
2.7
|
1.4
|
3.8
|
2.1
|
4.1
|
2.7
|
6.2
|
5.4
|
7.3
|
7.6
|
8.0
|
|
|
5
|
|
|
0.3
|
0.6
|
0.4
|
1.6
|
0.7
|
2.1
|
0.8
|
2.3
|
1.2
|
3.2
|
2.1
|
3.6
|
2.9
|
4.0
|
|
|
30
|
|
|
2.6
|
5.2
|
3.9
|
8.4
|
5.7
|
10.5
|
10.5
|
13.6
|
13.6
|
16.8
|
19.9
|
18.9
|
27.9
|
20.8
|
|
|
25
|
|
|
1.8
|
3.7
|
2.9
|
6.2
|
4.0
|
8.4
|
6.4
|
10.5
|
8.9
|
14.7
|
14.9
|
17.7
|
20.9
|
19.5
|
|
|
20
|
|
|
1.3
|
2.5
|
2.2
|
4.6
|
2.9
|
6.6
|
4.2
|
8.0
|
5.8
|
11.3
|
10.8
|
14.4
|
15.1
|
15.8
|
|
5
|
15
|
|
|
0.8
|
1.6
|
1.4
|
3.2
|
2.0
|
5.1
|
2.6
|
6.2
|
3.6
|
8.4
|
6.8
|
10.8
|
9.5
|
11.9
|
|
|
10
|
|
|
0.5
|
|
0.8
|
2.1
|
1.2
|
3.1
|
1.4
|
4.0
|
2.1
|
5.8
|
3.8
|
7.2
|
5.3
|
7.9
|
|
|
5
|
|
|
|
|
0.3
|
1.2
|
0.5
|
1.8
|
0.6
|
2.2
|
1.0
|
3.1
|
1.5
|
3.6
|
2.1
|
4.0
|
|
|
30
|
|
|
|
|
3.1
|
6.2
|
4.1
|
8.4
|
6.0
|
11.5
|
8.9
|
15.7
|
16.8
|
18.8
|
23.5
|
20.7
|
|
|
|
|
Outlet
|
Suction
|
ML, MLE Liquids
Exhausting Gases
|
1-1/2" Unit
|
|
Pressure
|
Pressure,
Ps
|
Motive Pressure
- Prn (PSIG)
|
|
|
|
20
|
40
|
60
|
80
|
100
|
140
|
200
|
250
|
|
Po
(psig)
|
(In
Hg Abs)
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
ML
|
MLE
|
|
|
25
|
|
|
|
|
2.3
|
4.9
|
3.1
|
7.0
|
4.3
|
9.4
|
6.4
|
13.5
|
11.2
|
17.6
|
15.7
|
19.4
|
|
|
20
|
|
|
|
|
1.6
|
3.6
|
2.3
|
5.5
|
3.2
|
7.5
|
4.6
|
10.7
|
7.7
|
13.9
|
10.8
|
15.3
|
|
10
|
15
|
|
|
|
|
1.1
|
2.7
|
1.6
|
4.0
|
2.3
|
5.6
|
3.1
|
7.8
|
4.9
|
10.6
|
6.9
|
11.7
|
|
|
10
|
|
|
|
|
0.7
|
1.5
|
1.0
|
2.8
|
1.3
|
3.8
|
1.8
|
5.6
|
2.9
|
7.0
|
4.1
|
7.7
|
|
|
5
|
|
|
|
|
0.3
|
|
0.5
|
1.5
|
0.6
|
2.2
|
0.8
|
3.0
|
1.2
|
3.6
|
1.7
|
4.0
|
|
|
30
|
|
|
|
|
|
|
3.3
|
7.4
|
4.6
|
9.9
|
6.5
|
14.7
|
11.5
|
18.9
|
16.1
|
20.8
|
|
|
25
|
|
|
|
|
|
|
2.6
|
6.0
|
3.5
|
8.1
|
5.2
|
12.3
|
9.0
|
16.7
|
12.6
|
18.4
|
|
|
20
|
|
|
|
|
|
|
2.0
|
4.8
|
2.7
|
6.7
|
4.0
|
10.4
|
6.7
|
13.5
|
9.4
|
14.9
|
|
15
|
15
|
|
|
|
|
|
|
1.4
|
3.7
|
1.9
|
5.2
|
2.7
|
7.6
|
4.5
|
10.4
|
6.3
|
11.4
|
|
|
10
|
|
|
|
|
|
|
0.9
|
2.5
|
1.2
|
3.6
|
1.6
|
5.5
|
2.5
|
6.9
|
3.5
|
7.6
|
|
|
5
|
|
|
|
|
|
|
0.4
|
1.0
|
0.6
|
2.1
|
0.8
|
3.0
|
0.9
|
3.6
|
1.3
|
4.0
|
|
|
30
|
|
|
|
|
|
|
3.0
|
|
3.8
|
8.9
|
5.8
|
13.6
|
8.9
|
17.8
|
12.5
|
19.6
|
|
|
25
|
|
|
|
|
|
|
2.3
|
|
3.1
|
7.5
|
4.6
|
11.7
|
7.2
|
16.4
|
10.1
|
18.0
|
|
|
20
|
|
|
|
|
|
|
1.6
|
|
2.4
|
6.3
|
3.5
|
9.6
|
5.4
|
13.2
|
7.6
|
14.5
|
|
20
|
15
|
|
|
|
|
|
|
1.1
|
|
1.6
|
4.9
|
2.5
|
7.5
|
3.7
|
10.1
|
5.2
|
11.1
|
|
|
10
|
|
|
|
|
|
|
0.7
|
|
1.1
|
3.4
|
1.4
|
5.5
|
2.3
|
6.9
|
3.2
|
7.6
|
|
|
5
|
|
|
|
|
|
|
0.2
|
|
0.6
|
1.9
|
0.8
|
3.0
|
1
0.9
|
1
3.6
|
1.3
|
4.0
|
|
Motive Flow, Qm (GPM)
|
18.8
|
18.0
|
25.4
|
24.2
|
30.4
|
28.2
|
34.7
|
31.7
|
38.5
|
34.7
|
45.2
|
40
|
53.2
|
45.9
|
59.2
|
50.3
|
|
|
|
| |
|
ML,
MLE, SG, HG -- Sizing Factors
(S.F.)
|
|
Unit
Size
|
1/2"
|
3/4"
|
1"
|
1-1/4"
|
1-1/2"
|
2"
|
2-1/2"
|
3"
|
4"
|
6"
|
8"
|
10"
|
12"
|
|
S.F.
|
0.12
|
0.21
|
0.34
|
0.61
|
1.00
|
1.82
|
3.17
|
5.92
|
11.8
|
24.0
|
49.0
|
71.0
|
123.0
|
|
|
|
|
|
| |
| |
|
|
| |
