in industries like iron and glass the fluid for hydraulic machines are delivered by multistage pumps. this is the basic introduction for clearing the concept of multi stage pumps.
2. CONTENT LAYOUT
• Intro.To pump
• Multistage pump
• Working principle and construction
• Working
• applications
3. PUMP
• Definition:
• The pump is a mechanical device which conveys liquid from one
place to another place.
• It can be defined as a hydraulic machines which converts the
mechanical energy into hydraulic energy (pressure energy of liquid)
• Basic working principle of pump:
• The pressure energy is increased by creating a region of low pressure
(lower then atmosphere) near the inlet of the pump and higher
pressure at outlet of the pump.
• Due to this low inlet pressure, the liquid rises to the pump from a low
level reservoir.
• The high pressure created delivery side of the pump by mean of
piston/plunger, impeller, propeller, gear/screw depending upon types
of pump.
4. MAJOR PARTS ANDTHEIR FUNCTIONS
• Seal : centrifugal pump can be provided with packing rings or mechanical seal which helps
prevent the leakage of the pumped liquid into the atmosphere.
• Shaft :The main function of the shaft in a centrifugal pump is to transmit the input power from
the driver into the impeller
• Casing :The casing contains the liquid and acts as a pressure containment vessel that directs
the flow of liquid in and out of the centrifugal pump.
• Impeller : Centrifugal pumps use impeller as the primary source for their pumping action. Its
function is to increase the pressure of the liquid.
• Bearing :The function of the bearing is to support the weight of the shaft (rotor) assembly, to
carry the hydraulic loads acting on the shaft, and to keep the pump shaft aligned to the shaft of
the driver.
• Coupling :The function of couplings are to connect the pump shaft and the driver shaft, and to
transmit the input power from the driver into the pump.
5.
6. Operation of surface mounted centrifugal
pump
• Never run pump dry
• If the pump is above the waterbody then it cannot pump only air. It
needs primed.
• Primed means the pump casing has to be filled with water before
starting the pump.
• Better to start the pump against a closed value- this reduces the
power needed for start
7. MULTI-STAGE CENTRIFUGAL PUMP
• A pump stage is defined as that portion of a centrifugal pump
consisting of one impeller and its associated components.
• Most centrifugal pumps are single-stage pumps containing
only one impeller.
• A pump containing seven impellers within a single casing
would be referred to as a seven-stage pump or generally
considered as a multi-stage pump.
8. • A centrifugal pump with a single impeller that can develop a
differential pressure of more than 150psi between the suction
and the discharge is difficult and costly to design and construct.
• A more economical approach to developing high pressures with
a single centrifugal pump is to include multiple impellers on a
common shaft within the same pump casing at moderate
speed.
• Internal channels in the pump casing route the discharge of one
impeller to the suction of another impeller.
9. • The water enters the pumps from the top left and passes through each of the four
impellers in series, going from left to right.
• The water goes from the volute surrounding the discharge of one impeller to the
suction of the next impeller.
WORKING
10. APPLICATIONS
• These pumps are commonly used in pressure boosting systems where circumstances
demand constant pressure and flow such as
• in high density living
• industrial applications requiring substantial wash down facilities
• boiler feed systems
• jacking pumps for fire hydrant systems
• fire hose reel supply and irrigation systems.
11. BOOK:
FLUID POWER ENGINEERING BY J.P. HADIYA
SITES:
ALL PUMPS: HTTPS://
WWW.ALLPUMPS.COM.AU/APPLICATIONS/MULTISTAGE-PUMPS
KIRLOSKAR PUMPING:
HTTP://WWW.KIRLOSKARPUMPS.COM/PRODUCT-PUMP-MULTISTAGE-
PUMPS.ASPX
References: