| 2.Brief
Description of Construction and Operation Principle
B.
Description of Main parts
(1)The injection water
pump in cast is composed of thefollowing parts: a. Nozzle: b.Suction chambor;
c. Mixing chamber; d. diffusero
(2)ZcuA19Mn2 is used
for nozzle, for which hydraulic test must be carried otu after machining ZcuZn16si4
or HT200 can be used for the suetion chamber, mixing chamber and diffuser in
easting construction. For them, hydraulic test for cheking strength should also
be carried out after machining.
(3)For stationary
injection water pump, its inlet, suction and discharge are all fitted with
maiine flanges, For portable injection water pump, marine fire nipple is used
for its inlet, suetion and discharge.
C.
Operation principle
Energy transfer in injection water
pump depends on fluid collision. Thatis, fluid in high pressure will increase
its speed aterflowing through nozzle, and will inject outward in high
speed, thereby decreasing the
pressure. This water jet carries away the air at iulet because of the viscons
drag between water jet and air so as to creat vacuum there, thereby water is
sucked in unber the effect of pressure difference.The water to be sucked is
mixed with water jet in high speed and is come into collision with it at the
inlet of mixing chamber and then flows into mixing chamber;Thus the speed of
Water jet is decreased, while the water to be sucked is increasing its speed.These
two speeds will become equal gradually until thcy are mixed with each other porfectlyo
At that time, the pressure in mixing chamber is increased graduallyo The mixed
water then flows into diffuser. so that the velocity head is converted into
pressure head and is discharged out of the diffuser.
This injection water pump is
a solf-ptiming pump and can operate steadiIy and
continuously.
The advantage of this pump is simple in mamufacturing and maintennance.
D,
Optima nozzle position
Different flowrates will be
produced with different positions. of nozzle even under the same working
condition. The position wdere max. flowrale can be produced by nozzle is
considered as an optimum nozzle position. the nozzle position shown on drawing
is the optimum nozzle position under norminal workihg condition. The optimuum
nozzle posltion can be adjusted by increasing or decreasing the number of sheet
gaskets between nozzle and pump boby because of the error in manufacturing.
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