1 pumps. 2 displacement pumps centrifugal pumps reciprocating pumps rotary pumps flexible impeller...
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Pumps
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Pumps
Displacement
pumps
Centrifugal
pumps
Reciprocating
pumpsRotary pumps
Flexible impeller pumps
Single stagepumps
Multi-stage pumps
Depends on principle ofthe work of the pumps
Screw pumps
Vane pumpsSpecial geometry
pump
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In some sources Displacement and Centrifugal pumps are split in groups differently comprising more applications
We are interested in marine applications!!!
http://www.pumpworld.com/tutorials.htm
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pumps
• A.C. motor—driven pumps
• D.C. motor—driven pumps
• Engine driven pumps
• Hydraulically driven pumps
• Manual pumps
Depends on forms of drive
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Characteristics of the PUMPS
• Head (vertical lift) measured in meters or feet• Capacity measured in litres per minute or gallon
per hour • Relation between head pressure and capacity• Self-prime or not self-prime• Ability to run dry (work out scenario of use)• Ability to passing solids• Chemical tolerance• Continuous duty
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Displacement pumps
• Self prime• Efficient for dealing with
small volumes and high differential pressure or head
• Can handle any required viscosity
• Can tolerate or not solids depends on the valve construction
• Dry run tolerance depends highly on the construction
• Valves and diaphragms could be susceptible to chemical damage
Displacement Reciprocating pump
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Displacement Reciprocating pumps
• Double acting
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Displacement Diaphragm pumps
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Displacement Variable volume impeller pumps
Flexible impeller pump
Vane pump
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Displacement Screw Pump
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Centrifugal pumps
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Centrifugal pumps• Not self-prime – position bellow liquid level
or to be primed• Widest application for dealing with large
volumes with a medium—to—low heads and viscosities
• Moderate tolerance for solids – the large the pump, the more tolerant
• Can run dry• May have chemical tolerance depends on
the sealing type
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Centrifugal pump performance curve
All pump manufacturers have a graphs that show pump output as a function of head pressure
Total head include required head of the system plus all losses, expressed in head pressure
bilge
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Blockage of the discharge
• Centrifugal pump – simply responds by moving less fluid until it spins to no effect – the current drawn drops down
• Displacement pump – builds up the pressure and loads the motor – the current drawn increases. This process continue until something will burn, break or pipe-work burst out
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When chose pump
• Check with care in the pump manufacturer manual or instructions how well pump characteristics (slide 5)meet system requirements!!!