Pumps, centrifugal reciprocating

Pumps (centrifugal, reciprocating) Fluid density, capacity, dynamic head, type, driver, operating condition limits, material of construction... 

Related Calculations. Use the techniques given here for any type of pump—centrifugal, reciprocating, or rotary—handling any type of liquid—oil, water, chemicals, etc. The methods given here are the work of Melvin Mann, as reported in Chemical Engineering, and Peerless Pump Div. of FMC Corp. 

Applications include electric motor drives for conveyors and other material handling equipment such as stacker reclaimers, crushers, haulages, ball mills, cranes, hammer mills, rotary dryers, centrifuges, reciprocating pumps, winches, fans and wire drawing machines. 

Pumps Centrifugal Vertical mixed flow Vertical axial flow Gear pumps Reciprocating pumps... 

Related Calculations. Use this procedure for any liquid-water, oil, chemical, sludge, etc.—whose specific gravity is known. When liquids other than water are being pumped, the specific gravity and viscosity of the liquid must be taken into consideration. The procedure given here can be used for any class of pump—centrifugal, rotary, or reciprocating. 

The kind of information needed for the specification of centrifugal, reciprocating and rotary pumps is shown on forms in Appendix B. 

There are three main classifications for pumps used in the chemical industry centrifugal, reciprocating, and rotary. 

High-pressure pumps Used in many applications including water blast, hydromining, and jet cutting. They can be a wide variety of pump types including positive displacement pumps, rotary pumps, and reciprocating pumps or centrifugal pumps. 

Positive Pumps. Positive pumps employed by the food industry have a rotating cavity between two lobes, two gears that rotate in opposite directions, or a crescent or stationary cavity and a rotor. Rotary positive pumps operate at relatively low speed. Fluid enters the cavity by gravity flow or from a centrifugal pump. The positive pump also may use a reciprocating cavity, and may be a plunger or piston pump. These pumps are not truly positive with respect to displacement, but are used for metering product flow. 

From the definition of specific speed (eqs. 9 and 10), it follows that reciprocating pumps operate at high pressures and low flow rates. Conversely, centrifugal pumps are appHed at lower pressures and higher flow rates. Many rotary pumps are selected for viscous Hquids having pressures equal to or less than, and capacities lower than, centrifugal pumps. However, these limits are relative and a gray area exists as some pump types cross boundaries into the domain of other types. 

Hydraulic Institute Standardsfor Centrifugal, Rotay Reciprocating Pumps, Hydraulic Institute, Parsippany, N. J., 1994. 

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