MST ZW, Operation

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02
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This pump casing consists of a suck-in room, a liquid
storing room, a scroll room, a liquid back hole, an a ir-liquid
separating room etc. a nd h olds a n ax ially-liquid-back st ructure.
After the pump is normally started, the impeller sucks i n t he
all liquid inside of the suck-in room and the air inside of
the pipeline and gets them completely mixed inside of it,
then, under the action of the centrifugal force, the liquid,
carrying the air, flows towards the outer edge of the scroll
room and, on the outer edge of the impeller, a white foam
band of a certain thickness and a quickly rotating l iquid r ing
are formed. The air-liquid mixture gets into the air-liquid
separating room through the expanding pipe and, as t he f low
-rate is abruptly lowered thereafter, the lighter air is separ-
ated from the mixture and rises through the vomit port of
the pump casing and is exhausted therefrom. T he l iquid w ith
the air off returns to the liquid storing room and gets into
the impeller again through the liquid back hole, where it is
mixed again with the air sucked in from the suck-in pipe-
line and, under the action of the quickly rotating impeller,
flows towards the outer edge of the impeller again , al-
ong with the repeated process, the air in t he s uck-in p ipeline
is continually reduced till being sucked up, the self-suction
process ends and the pump gets into the normal work. This
unique exhaust capacity makes the pump able to transport
the air-contained liquid without a foot valve mounted and
of a good cabin cleaning function when used on an oil ship.
There is a cooling room on the bottom of the bearing
body with some pumps and, when the bearing body's temp-
erature rise is over 70oC with the bearing heated, the cool-
ing liquid can be injected in through any one of the cooling
liquid unions in the cooling room for cycled cooling. The
sealing mechanism inside of the pump used to prevent the
liquid from leaking from the high pressure area to the low
one is the front and rear seal rings, the front ring is mount-
ed on the pump casing a nd t he r ear o ne o n t he b earing b ody.
When the seal ring gets worn out to a certain extent after a
long time work of the pump and thus affecting both effici-
ency and self-suction property of it, it should be replaced.
ZW SELF-PRIMING PUMP