V
S
Non-return valve
r
B
Regulating valve
r
C
(=PC) Regulating valve (anti-cavitation)
r
F
Regulating valve
r
F1
Regulating valve (float valve)
r
F2
Regulating valve (thermostatical)
r
F3
Regulating valve (pressure reducer)
r
K
Regulating valve (cooling water)
l
B
Operating liquid pipe
l
c
Anti-cavitation pipe (optional)
l
F
Fresh liquid pipe
l
K
Cooling liquid pipe
l
S
Suction pipe
l
D
Discharge pipe
l
U
Circulation pipe
m
a
(=Li)
Level indicator
m
B
(=Pi) Compound (vacuum & pressure) gauge
m
D
Pressure gauge
m
t
(=Ti)
Thermometer
m
t1
Temperature sensor to r
F2
U
A
Liquid discharge
U
B
Connection for operating liquid
U
S
Suction pipe connection
U
D
Discharge pipe connection
U
E
Drain (liquid separator)
U
e
Drain (pump)
U
U
Connection for circulation liquid
Once Through Operation / No Recovery
The operating liquid is taken directly from a main supply to
the-vacuum pump. The operating liquid is separated from the gas and
wasted to a drain. No recirculation or recovery takes place. This ar-
rangement can be used where operating liquid conservation or con-
tamination are not a concern. An automatic solenoid valve can provide
for flow of operating liquid simultaneously with -vacuum pump opera-
tion (i.e. upon motor stopping, the valve closes preventing the housing
to be filled with too much operating liquid). With a manual operating
liquid shut off valve, it is
i m p o r t a n t
to open valve immediately after
starting the motor and to close the valve immediately before switching
the motor off.
Version with lateral liquid separator:
Version with top liquid separator:
Circuit diagram:
Alternative tank with float valve:
Partial Recovery
The operating liquid enters and leaves the vacuum pump in the same
manner as with the once through arrangement. A portion of the oper-
ating liquid is recirculated from the separator tank to the vacuum
pump. The remainder is discharged from the separator and wasted to
the drain. The fresh liquid F is introduced in sufficient quantity to main-
tain proper temperature essential for good vacuum pump performance.
This type of arrangement is used where seal liquid conservation is pos-
sible, and, if other than water is utilised, the consumption can be re-
duced by upto 50 percent depending upon the fluid vapour pressure
and temperature.
The operating liquid level in the separator/recirculation tank should be
at, or slightly below, the centreline of the pump shaft. Provisions may
also be made for high level overflow. This will help prevent starting the
vacuum pump with the housing full of water, which could overload the
vacuum pump and the drive motor.
Version with lateral liquid separator:
LA 0053-1111 A, LB 0063-1011 A
Installation and Commissioning
0870150638 / 091222
page 6
Summary of Contents for DOLPHIN LA 0053-0143 A
Page 27: ......
