pumps and its types-ppt
TRANSCRIPT
Pump classification
Hydrodynamic (or) non-positive displacement
pumps
Hydrostatic (or) positive displacement pumps
Carries fluid from one location to another, relatively at low pressure (17-21 bar).
Generally used for low pressure, high-volume, flow applications.
These pumps are not self-priming, as there is a great deal of clearance between the rotating and stationary elements.
Cannot create enough vacuum at its inlet, hence discharge rate is low.
Examples….. a) Centrifugal pumps b) Axial flow propeller pump.These pumps are called as non-positive
displacement pumps.
HYDRODYNAMIC PUMPS
Hydrostatic pumpsHydrostatic pumps uses fluid pressure to
transmit power.These pumps have very close-fitting
mating components and hence a very small amount of leakage could occur.
These pumps may be either….. a) Fixed displacement b) Variable displacementThese pumps requires protection against
over pressure if the resistance to flow becomes very large or infinite, so pressure relief valve is provided.
It is also called as positive displacement pumps.
Common external gear pump applications include, but are not limited to:Various fuel oils and lube oilsChemical additive and polymer meteringChemical mixing and blending (double pump)Industrial and mobile hydraulic applications (log splitters, lifts, etc.)Acids and caustic (stainless steel or composite construction)Low volume transfer or application
APPLICATION
Common internal gear pump applications include, but are not limited to:All varieties of fuel oil and lube oilResins and PolymersAlcohols and solventsAsphalt, Bitumen, and TarPolyurethane foam (Isocyanate and polyol)Food products such as corn syrup, chocolate, and peanut butterPaint, inks, and pigmentsSoaps and surfactantsGlycol
APPLICATION
Common rotary lobe pump applications include, but are not limited to:PolymersPaper coatingsSoaps and surfactantsPaints and dyesRubber and adhesivesPharmaceuticalsFood applications
APPLICATION
PD pumps are found in a wide range of applicationchemical-processingliquid deliverymarinebiotechnology pharmaceuticalas well as food, dairy, and beverage processing. Their versatility and popularity is due in part to their relatively compact design, high-viscosity performance, continuous flow regardless of differential pressure, and ability to handle high differential pressure.
APPLICATIONS OF PDP
Aerosol and PropellantsAviation Service - Fuel Transfer,
DeicingAuto Industry - Fuels, Lubes,Refrigeration CoolantsBulk Transfer of LPG and NH3LPG Cylinder FillingAlcoholsRefrigeration - Freons, AmmoniaSolventsAqueous solutions
APPLICATION
NON-POSITIVE DISPLACEMENT PUMPS
POSITIVE DISPLACEMENT PUMPS
provide a smooth, continuous flow
pulse with each stroke or each time a pumping chamber opens to an outlet port.
Pressure can reduce a non positive pump's delivery. High outlet pressure can stop any output; the liquid simply recirculates inside the pump
In a positive-displacement pump, pressure affects the output only to the extent that it increases internal leakage
It is not self priming It is a self-priming
CHARACTERISTICS OF PUMPS
PERFORMANCE OF PUMP Pumps are usually rated according to their
volumetric output and pressure. Volumetric output (delivery rate or capacity) is the
amount of liquid that a pump can deliver at its outlet port per unit of time at a given drive speed, usually expressed in GPM or cubic inches per minute.
Pumps are sometimes rated according to displacement, that is the amount of liquid that they can deliver per cycle or cubic inches per revolution.
As pressure increases, volumetric output decreases. This drop in output is caused by an increase in
internal leakage (slippage) from a pump's outlet side to its inlet side
Slippage is a measure of a pump's efficiency and usually is expressed in percent.
PUMP EFFICIENCIESVolumetric Efficiency:η = Actual flow rate = Qa Theoretical flow rate QtGear pumps = 80-90 %Vane pumps = 82-92 %Piston pumps = 90-98 % Mechanical Efficiency:η = Output power = Po Input power PiMechanical efficiency varies from 90 to 95 %Overall Efficiency:η = Actual power delivered by the pump = Hydraulic power Actual power delivered to the pump Brake power
REFFRENCE1. WWW.PUMPSSCHOOL.COM 2. APPLIED HYDRAULICS AND
PNEUMATICS By T.Sunder Selwyn, R.Jayendiran
3. www.authorstreem.com.