Lift-pump.
A (
Fig. 2941) shows one form of modern lifting-pump.
The head of the pump is closed, and the water may be lifted through the side tube to any elevation consistent with the strength of the tube.
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Lift-pumps. |
B is a double-piston pump adapted to situations where the pump cannot be conveniently inserted in the reservoir.
The piston of the atmospheric pump is directly under that of the lifting-pump, and works in a cylinder attached to the bottom of the cistern.
Each is attached to the same rod and worked by the same frame.
In
C two pistons
a b are placed in two cylinders, side by side, and are operated simultaneously by attachment to a cross-head, both drawing up the water at the same time.
The downward movement, as it closes the valve
c, forces the water upward through the cylinder
a, maintaining a continuous discharge.
D (
Fig. 2942) is an atmospheric pump.
The upper valve is of peculiar construction.
F is a solid-piston pump, which lifts the water to the barrel, and on its downward stroke forces water up the pipe.
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1307]
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Lift-pumps. |
G is a double-cylinder balance-beam pump.
The pistons are alternately raised and lowered by a man throwing his weight alternately on either side of the beam, and discharge the contents of the cylinders through the pipe
a. h is a plan of the beam and its frame, on which the man stands.
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Muschenbroeck's lift-pump. |
In Lecorche's pump (to the right), the cylinder
a is surrounded by an airtight vessel
b, which, being originally filled with water to a hight sufficient to cover the piston, always keeps the valve wet. Each stroke creates a vacuum in the vessel
b, causing the water to rise in the cylinders
a c, whose valves are lifted at the same time.
This arrangement also obviates the shock caused by the water when the piston is worked rapidly.
Fig. 2943 is a pump described by Muschenbroeck.
The upper end of the suction-pipe
a enters a small cistern
b, and is surrounded by a cylinder
c, the lower part of which fits closely around it. The valves of both open upwardly.
The upward movement of the cylinder
c causes a vacuum in both it and
a, which become filled with water, the downward movement of
c causing the water therein to overflow into the cistern
b, whence it is discharged.
