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Dynamic pumps are a variety
of velocity pumps in which kinetic energy is added
to the fluid by raising the flow velocity. This
increase in energy is transformed to a gain in
potential energy (pressure) when the velocity is
decreased before or as the flow exits to the
discharge line. This change in kinetic energy to
pressure is defined by the First law of
thermodynamics, or more accurately, by Bernoulli’s
principle.
Dynamic pumps can be subdivided according to how the
velocity gain is achieved. |
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| These kinds of pumps
have some characteristics: |
- Conversion of added energy to rise in
kinetic energy (increase in velocity)
- Continuous energy
- Conversion of increased velocity (kinetic
energy) to make a higher pressure head.
- A functional difference between
positive-displacement and dynamic pumps is how
they work under closed valve states.
Positive-displacement pumps physically move
fluid, so closing a valve downstream of a
positive-displacement pump provides a continual
pressure build-up that can lead to mechanical
failure of the pipeline or pump. Dynamic pumps
vary in that they can operate safely under
closed valve conditions (for short periods)
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| These pumps are classified into various types: |
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