Difference between revisions of "Diaphragm Pumps"
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[[Category:Pumps]]{{Knoppen}} | [[Category:Pumps]]{{Knoppen}} | ||
[[File:Diaphragm Pump.jpg|thumb|right|Diaphragm Pumps]] | |||
[[File:Diaphragm Pumps1.jpg|thumb|right|Diaphragm Pumps]] | |||
'''Diaphragm Pumps''' also known as [[Membrane Pumps]], are positive displacement pumps that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable [[Valves]] either side of the diaphragm to pump a fluid. | |||
[[ | |||
==Types== | |||
There are three main types of diaphragm pumps: | There are three main types of diaphragm pumps: | ||
*Those in which the diaphragm is sealed with one side in the fluid to be pumped, and the other in air or hydraulic fluid. The diaphragm is flexed, causing the volume of the pump chamber to increase and decrease. A pair of non-return check valves prevent reverse flow of the fluid. | * Those in which the diaphragm is sealed with one side in the fluid to be pumped, and the other in air or hydraulic fluid. The diaphragm is flexed, causing the volume of the pump chamber to increase and decrease. A pair of non-return check valves prevent reverse flow of the fluid. | ||
*Those employing volumetric positive displacement where the prime mover of the diaphragm is electro-mechanical, working through a crank or geared motor drive. | * Those employing volumetric positive displacement where the prime mover of the diaphragm is electro-mechanical, working through a crank or geared motor drive, or purely mechanical, such as with a lever or handle. This method flexes the diaphragm through simple mechanical action, and one side of the diaphragm is open to air. | ||
*Those employing one or more unsealed diaphragms with the fluid to be pumped on both sides. The diaphragm(s) again are flexed, causing the volume to change. | * Those employing one or more unsealed diaphragms with the fluid to be pumped on both sides. The diaphragm(s) again are flexed, causing the volume to change. | ||
When the volume of a chamber of either type of pump is increased , the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later increases from decreased volume , the fluid previously drawn in is forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, completing the cycle. This action is similar to that of the cylinder in an internal combustion engine. | |||
==Characteristics== | ==Characteristics== | ||
Diaphragm pumps: | Diaphragm pumps: | ||
* have good suction lift characteristics, some are low pressure pumps with low flow rates; others are capable of higher flow rates, dependent on the effective working diameter of the diaphragm and its stroke length. They can handle sludges and slurries with a relatively high amount of grit and solid content. | |||
* have good suction lift characteristics, some are low pressure pumps with low flow rates; others are capable of higher | |||
* suitable for discharge pressure up to 1,200 bar | * suitable for discharge pressure up to 1,200 bar | ||
* have good dry running characteristics. | * have good dry running characteristics. | ||
* can be used to make artificial hearts. | * can be used to make artificial hearts. | ||
* are used to make air pumps for the filters on small fish tanks. | * are used to make air pumps for the filters on small fish tanks. | ||
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* are available for industrial, chemical and hygienic applications | * are available for industrial, chemical and hygienic applications | ||
* cause a pulsating flow that may cause water hammer | * cause a pulsating flow that may cause water hammer | ||
==Air compressors== | |||
Small mechanically activated diaphragm pumps are also used as air compressors and as a source of low-grade vacuum. Compared to other compressors, these pumps are quiet, cheap and, most importantly, have no moving parts in the airstream. This allows them to be used without added lubrication in contact with the air, so the compressed air produced can be guaranteed clean. | |||
==Sources== | |||
[http://en.wikipedia.org/wiki/Diaphragm_pump Wikipedia Diaphragm Pumps] | |||
Latest revision as of 11:58, 8 January 2014
Diaphragm Pumps also known as Membrane Pumps, are positive displacement pumps that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable Valves either side of the diaphragm to pump a fluid.
Types
There are three main types of diaphragm pumps:
- Those in which the diaphragm is sealed with one side in the fluid to be pumped, and the other in air or hydraulic fluid. The diaphragm is flexed, causing the volume of the pump chamber to increase and decrease. A pair of non-return check valves prevent reverse flow of the fluid.
- Those employing volumetric positive displacement where the prime mover of the diaphragm is electro-mechanical, working through a crank or geared motor drive, or purely mechanical, such as with a lever or handle. This method flexes the diaphragm through simple mechanical action, and one side of the diaphragm is open to air.
- Those employing one or more unsealed diaphragms with the fluid to be pumped on both sides. The diaphragm(s) again are flexed, causing the volume to change.
When the volume of a chamber of either type of pump is increased , the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later increases from decreased volume , the fluid previously drawn in is forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, completing the cycle. This action is similar to that of the cylinder in an internal combustion engine.
Characteristics
Diaphragm pumps:
- have good suction lift characteristics, some are low pressure pumps with low flow rates; others are capable of higher flow rates, dependent on the effective working diameter of the diaphragm and its stroke length. They can handle sludges and slurries with a relatively high amount of grit and solid content.
- suitable for discharge pressure up to 1,200 bar
- have good dry running characteristics.
- can be used to make artificial hearts.
- are used to make air pumps for the filters on small fish tanks.
- can be up to 97% efficient.
- have good self priming capabilities.
- can handle highly viscous liquids.
- are available for industrial, chemical and hygienic applications
- cause a pulsating flow that may cause water hammer
Air compressors
Small mechanically activated diaphragm pumps are also used as air compressors and as a source of low-grade vacuum. Compared to other compressors, these pumps are quiet, cheap and, most importantly, have no moving parts in the airstream. This allows them to be used without added lubrication in contact with the air, so the compressed air produced can be guaranteed clean.