Pumps Flashcards
Two categories of pumps
Dynamic and positive displacement pumps
How do dynamic pumps work
They raise a liquids pressure by centrifugal force to produce velocity energy then converting it into pressure energy to move liquids
How do positive displacement pumps work
They use Pistons, diaphragms, vanes, loves, screws, or gears to deliver a constant volume with each stroke.
Centrifugal pump
A type of dynamic pump that uses an impeller on a rotating shaft to generate pressure and move liquids
Viscosity
The degree to which liquid resist flow under applied force
Type of centrifugal pumps
Single stage and multistage
How does a single stage centrifugal pump work
It uses a disk shaped impeller to impart kinetic energy and velocity to the pumped liquid.
The liquid enters the pumps, the pressure is increased on time, then the liquid exits the pump
What happens in a multistage pump
The liquid enters the pump and the pressure is increased multiple times before it exits the pump.
They contain two or more impellers on a single shaft. The discharge of one impeller enters into the suction of the next to increase the pressure of the liquid.
What applications are multistage pumps used in
High volume, high pressure applications such as boiler feed water pumps
Canned pumps
Are sealless pumps that ensure zero emissions. Often used on difficult liquids to seal such as liquefied gases, and liquids regulated by the EPA.
Axial pumps
Type of dynamic pump that use a propeller or row of blades to propel liquids parallel to the pumps shaft
What applications are axial pumps used for
Used in applications where large amounts of liquid is circulated without much pressure.
Used for commercial and municipal sewage Power plants (providing water from lakes or reservoirs for cooling) Chemical plants (moving liquids used in evaporators and crystalizers) Agricultural use (irrigation and drainage)
