Handbook of Civil Engineering Calculations

TABLE

3.

Effect

of

Entrained

or

Dissolved

Gas on the

Liquid Displacement

of

Rotary Pumps (liquid displacement: percent

of

displacement)

5%10%

91 88%83% 7455

Gas

entrainment

and gas

solubility combined2% 3% 4%4% 6% 8%96!/

96 92 2

95

90 90

93

89!/

86!/ 2

2

88

83 78

75

1 X

68 61 2

1%2%^198

X^2

97

1 X

2

969485

1 X

2

10% 97

1 X

2

95 9O

1 X

2

8366

Gas

solubility

4%

6% 8

99

98

1 X

(^972)
97
1 X
97 95 2
96
94 92
92 89 86 83
76
1 X
(^712)
2% 99
1 X
2
99979690
5%^193
X^2
92 9O
1 Xa
86
1 X
2
75
1 X
2
Gas
entrainment
2% 3% 4%^197
X^2
96
1 X
(^952)
97%
95
1 X
(^942)
96
1 X
(^942)
1 X
(^922)
1 X
2
94
1 X
92 89 2
89
84 79
1% 99198
X^2
9897
1 X
2
94
Vacuum
at
pump
inlet,
in
Hg
(mmHg) 5 (127)
10(254)15(381) 20
(508)
25
(635)
For
example, with
5
percent
gas
entrainment
at 15 in Hg
(381 mmHg) vacuum,
the
liquid displacement will
be
9O
1 X
percent 2
of the
pump displacement,
neglecting slip,
or
with
10
percent dissolved
gas
liquid displacement will
be
9O
1 X
percent 2
of the
pump
displacement;
and
with
5
percent entrained
gas
combined
with
10
percent dissolved gas,
the
liquid displacement will
be
83%
percent
of
pump replacement.
Source:
Courtesy
of
Kinney
Mfg. Div.,
The New
York
Air
Brake
Co.