Submersible pump
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A submersible pump (or electric submersible
pump (ESP) is a device which has a hermetically
sealed motor close-coupled to the pump body. The
whole assembly is submerged in the fluid to be
pumped.
A submersible pump is a pump that is able to be placed
underwater and still carry out its intended purpose.
Some pumps may be designed to work while being fully
submerged, whereas others may be submerged or
placed in a dry area.
A submersible water pump pushes water to the surface,
instead of sucking the water out of the ground like
above ground water pumps.
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Working principle
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The submersible pumps used in ESP installations are
multistage centrifugal pumps operating in a vertical
position. Although their constructional and
operational features underwent a continuous
evolution over the years, their basic operational
principle remained the same.
Produced liquids, after being subjected to great
centrifugal forces caused by the high rotational speed
of the impeller, lose their kinetic energy in the
diffuser where a conversion of kinetic to pressure
energy takes place.
•The pump shaft is connected to the protector by a
mechanical coupling at the bottom of the pump. Well
fluids enter the pump through an intake screen and
are lifted by the pump stages.
•Other parts include the radial bearings (bushings)
distributed along the length of the shaft providing
radial support to the pump shaft turning at high
rotational speeds.
•An optional thrust bearing takes up part of the axial
forces arising in the pump but most of those forces
are absorbed by the protector’s thrust bearing.
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Applications
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Submersible pumps are found in many applications:
Single stage pumps are used for drainage, sewage
pumping, general industrial pumping and slurry
pumping.
They are also popular with aquarium filters.
Multiple stage submersible pumps are typically
lowered down a borehole and used for water
abstraction, water wells and in oil wells.
ADVANTAGE
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Efficiency: Compared to the ordinary pumps, the
submersible pumps are more efficient as it pumps
liquid which is close to the pump. It therefore
functions less than the ordinary pumps. As these
pumps are placed inside the sumps, it can detect the
level of water quite easily.
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Noise level: The submersible pumps seldom
produce less amount of noise as it is submerged
under water. The walls of the sump help to soften the
sounds caused by the pumps. The ordinary pumps
are placed outside the wells or sumps which creates a
huge amount of noise.
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Safe: These pumps are quite safe compared to the
other types of pumps as all the potential dangerous
components of the pumps are placed under water. It
is usually covered and seldom involves the prospects
of children tampering with its internal components
and valves.
DISADVANTAGE
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The largest disadvantage of these pumps is that
you put it in the water. This means it will have a
shorter life because it is sitting in and sucking up
muck from your pond. It is also harder to clean and
maintenance because it is sitting on the bottom of
the pond.
There is the chance the pump will become
corroded and lose its seals, thus allowing liquid to
penetrate into the motor housing and causing
substantial damage to the unit.
