Pump

Pumps Pumps

1

Prepare by:-Shivkumar PanjabiPrepare by:-Shivkumar Panjabi

Prepare by:-Shivkumar Panjabi

INTRODUCTIONThe pump is 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.

The pump is power absorbing machine.The power can be supplied to the pump by a prime mover like an electric motor, an internal combussion engine or turbine..

2 Prepare by:-Shivkumar Panjabi

It is classified into positive displacement pumps and rotodynamic pumps.

• In positive displacement pumps-its operate on a principle of liquid discharge or displaced due to the positive or real displacement of working element. In rotodynamic pumps-its operate on a principle of the rise in pressure energy of liquid by dynamic action of liquid which is carried out by impeller.

Classification of pumps


Pumps Classifications

4Prepare by:-Shivkumar Panjabi

Head: Head: Pressure is needed to pump the liquid through the system at a certain rate. This pressure has to be high enough to overcome the resistance of the system, which is also called “head”.

.Different Types of Pump HeadDifferent Types of Pump Head Static Suction Head Static Suction Head – It is the vertical height of the center line

of pump shaft above the surface of liquid or it is energy required to lift liquid from sump to pump.

Static Discharge Head Static Discharge Head - – It is the vertical height of the center line of pump shaft to where liquid is delivered or it is energy required to lift liquid from pump to end of delivery pipe.

Total Static Head Total Static Head - Total head when the pump is not runnig. h = hs + hd Total Dynamic Head (Total System Head) Total Dynamic Head (Total System Head) - Total head when

the pump is running Velocity headVelocity head-Kinetic energy carried away by the liquid at the

end of delivery pipe. hv = V^2/2g Manometric head-Manometric head-The total head required to developed by the

pump. Hm = hs +hd +hfs + hfd +hv Water power (PwWater power (Pw) = Power required by pimp to handle the

liquid to devlope manometric head. Shaft power(Ps) Shaft power(Ps) –it is the power input by shaft of the pump by

motor. Efficiency = Pw / PsEfficiency = Pw / Ps


Static Suction Head

Pump HeadPump Head

Static Delivery Head

Total Head


Operations of single acting reciprocating pump


Single Acting Reciprocating Pump

Working of single acting Reciprocating Pump


Operation of double acting reciprocating pump


Double Acting Reciprocating pump

Discharge Pipe

Piston Rod

Inlet Valves

Outlet Valves


Air vessel is a closed chamber containing compressed air in the upper part and liquid being pumped in the Lower part.Purpose:To get continuous supply of liquid at a uniform rateTo save considerable amount of work in overcoming the frictional resistance in suction and deliver pipes.To run the pump at much higher speed without any danger of separation.

Air Vessels



Principle: When a certain mass of fluid is

rotated by an external source, it is thrown away

from the central axis of rotation and a centrifugal

head is impressed which enables it to rise to a

higher level.

•A device which used to converted mechanical

energy into pressure energy by means of

centrifugal force acting on the fluid,for conveying

liquid from one place to nother is called

centrifugal pump.

Working Principle of Centrifugal pump


Main parts of a centrifugal pumpImpellerCasingSuction pipe with foot-valve and a

stainerDelivery pipe



Centrifugal Pumps


Types of centrifugal pumps According to type of casting1.Volute type pump2.Vortex type pump3.Diffuser type pump According to number of stages1.Single stage2.Multi stage




20

Centrifugal PumpsHow do they work?

• Liquid forced into impeller

• Vanes pass kinetic energy to liquid: liquid rotates and leaves impeller

• Volute casing converts kinetic energy into pressure energy


Centrifugal Pump - Working


Volute Casing: In this type of casing the area of flow gradually increases from the impeller outlet to the delivery pipe.

Vortex Casing: If a circular chamber is provided between the impeller and volute chamber the casing is known as Vortex Chamber.

Diffuser Casinng : The impeller is surrounded by a diffuser.The guide vanes are designed in such a way that the water from the impeller enters the guide vanes without shock. It reduces the vibration of the pump. Diffuser casing, the diffuser and the outer casing are stationery parts.

Volute and Diffuser casing


The operation of filling the suction pipe, casing and a portion of delivery pipe with the liquid to be raised, before starting the pump is known as Priming

It is done to remove any air, gas or vapour from these parts of pump.

Priming of a centrifugal Pump


Rotary pumps

A rotary pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside of a cavity. In some cases these vanes can be variable length and/or tensioned to maintain contact with the walls as the pump rotates


Classification of rotary pump

Gear pumpVane pumpScrew pump


• Gear pumps are primarily used for high-viscosity liquids. Two or more gears trap liquid in the space between the gear teeth and the casing wall and convey it from inlet to outlet. Obviously, it is essential to minimize paths through which liquid could flow backward.



Sliding vane pumps

28

The vanes are a sliding fit in slots cut in the rotor. The rotor turns eccentric to the casing, causing the cavities to decrease in volume. Vanes can be forced out by centrifugal force, use springs or utilise the pressure of the discharge liquid.



Twin-screw pumps

30

Due to the imbalance of forces, this type of pump often has the suction arranged at the centre of the Shdft screws and the delivery at either end, and is often driven through timing gears, which keep the screws from contacting each other.

Due to the imbalance of forces ,this type of pump often has the suction arranged at the centre of the shaft screws and the delivery at either end ,and is often driven through timing gears,which keep the screws from contacting each other.


Thank you for your attention

Education

Pump