Active Learning Assignment, FFO, BE- Sem 3rd – 2nd year Pumps Active Learning Assignment, FFO, BE- Sem 3rd – 2nd year Prepared by: Keval (130420105030) Kevin (130420105031) Kaushal (130420105029) Suhag (130420105028) Maipath (130420105027)

Chemical Engineering Department CONTENTS Introduction Classification Positive displacement pump Rotary pump Vane pump Gear pump Reciprocating pump Piston pump Plunger pump Application Chemical Engineering Department

Chemical Engineering Department Introduction The 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.. Chemical Engineering Department

Classification Chemical Engineering Department PUMP Positive Displacement Rotary Gear Vane Reciprocating Piston Plunger Dynamic Centrifugal Axial Chemical Engineering Department

Positive displacement pump How do they work? They make fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe. Theoretically can produce the same flow at a given speed (RPM) no matter what the discharge pressure called “constant flow machines”. Must not operate against a closed valve on the discharge side of the pump, it has no shutoff head like centrifugal pumps When operating against a closed discharge valve it continues to produce flow and the pressure in the discharge line increases until the line bursts, the pump is severely damaged, or both. A relief valve on the discharge side of the positive displacement pump is therefore necessary Chemical Engineering Department

Chemical Engineering Department Rotary pump Positive displacement rotary pumps move fluid using a rotating mechanism that creates a vacuum that captures and draws in the liquid. It consists of a fixed casing with a rotor which may be in the form of gears, lobes, screws, cams etc. It is suitable for pumping viscous fluids like vegetable oil, lubricating oil, alcohol, grease, tar etc. It is classified into: Gear pump Vane pump Chemical Engineering Department

Chemical Engineering Department Vane pump A hydraulic pump that uses a series of flat protrusions that rotate to trap and move liquid through a hydraulic system. Vane pumps are efficient at high speeds of operation. Chemical Engineering Department

Chemical Engineering Department Working 1.  A slotted rotor is eccentrically supported in a cycloid cam.  The rotor is located close to the wall of the cam so a crescent-shaped cavity is formed.  The rotor is sealed into the cam by two side plates.  Vanes or blades fit within the slots of the impeller.  As the rotor rotates (yellow arrow) and fluid enters the pump, centrifugal force, hydraulic pressure, and/or pushrods push the vanes to the walls of the housing.  The tight seal among the vanes, rotor, cam, and side plate is the key to the good suction characteristics common to the vane pumping principle. Chemical Engineering Department

Chemical Engineering Department 2.  The housing and cam force fluid into the pumping chamber through holes in the cam (small red arrow on the bottom of the pump).  Fluid enters the pockets created by the vanes, rotor, cam, and side plate. 3.  As the rotor continues around, the vanes sweep the fluid to the opposite side of the crescent where it is squeezed through discharge holes of the cam as the vane approaches the point of the crescent (small red arrow on the side of the pump).  Fluid then exits the discharge port. Chemical Engineering Department

ADVANTAGE & DISADVANTAGES Can have two stuffing boxes Complex housing and many parts Not suitable for high pressures viscosity Not good with abrasives Handles thin liquids at relatively higher pressures Compensates for wear through vane extension Sometimes preferred for solvents, LPG Can run dry for short periods Can have one seal or stuffing box Develops good vacuum Chemical Engineering Department

Chemical Engineering Department Gear pump A Gear pump uses the meshing of gears to pump fluid by displacement. Gear pumps are positive displacement (or fixed displacement), meaning they pump a constant amount of fluid for each revolution. Gear pumps are a popular pumping principle and are often used as lubrication pumps in machine tools, in fluid power transfer units, and as oil pumps in engines. It consists of two or more gears. The rotation of these gears provides pumping action . Chemical Engineering Department

Chemical Engineering Department Working Gear pump uses two identical gears rotating against each other -- one gear is driven by a motor and it in turn drives the other gear. Liquid flows into the cavity and is trapped by the gear teeth as they rotate. Liquid travels around the interior of the casing in the pockets between the teeth and the casing. Finally, gears forces liquid through the outlet port under pressure. Chemical Engineering Department

Chemical Engineering Department Advantages: High speed High pressure No overhung bearing loads Relatively quiet operation Design accommodates wide variety of materials Disadvantages: Four bushings in liquid area No solids allowed Fixed End Clearances Chemical Engineering Department

Chemical Engineering Department RECIPROCATING PUMP Reciprocating pump is a positive displacement pump. In this pump, the liquid is discharged due to the simple to and fro motion or reciprocating motion of the piston or plunger working in the cylinder of the pump. Hence it is called Reciprocating pump. A definite quantity of liquid is discharged or displaced due to the positive or real displacement of the piston or plunger working in the cylinder. It is classified into: Piston pump Plunger pump Chemical Engineering Department

Single acting Reciprocating pump In the single acting pump, any one side of piston act upon the liquid. The pump consists of the piston, cylinder, suction pipe with suction valve, delivery pipe with delivery valve and prime mover whish drives the pump. Chemical Engineering Department

Chemical Engineering Department Forward stroke: The piston moves towards right, crank moves from 0° to 180°. This creates vacuum in the cylinder on the left side of piston causing the suction valve to open. The liquid enters the cylinder and fills it. Reverse stroke: The piston moves towards left, crank moves from 180° to 360°. This causes increase of pressure in the left side of cylinder. The delivery valve open and liquid is forced to delivery pipe. Chemical Engineering Department

Double acting Reciprocating pump In this pump, suction and delivery takes place simultaneously on opposite sides of piston. Forward stroke: The piston moves towards right side of cylinder, the liquid is sucked from sump through suction valve S1 . At this moment, the liquid on right side of piston is compressed, the delivery valve D2 opens and liquid is discharged through this valve. Chemical Engineering Department

Chemical Engineering Department Reverse stroke: The piston moves towards left side of cylinder, the liquid is sucked from sump through suction valve SB . At this moment, the liquid on left side of piston is compressed and delivered through valve DA . Chemical Engineering Department

Chemical Engineering Department Plunger pump A hand operated plunger pump consists of plunger, stuffing box, suction valve, delivery valve and handle. The pump is operated by handle. In order to prevent the leakage of the liquid, the stuffing box, gland and packings are used. Non return valves are fitted at the suction and delivery pipes preventing back flows. Chemical Engineering Department

Chemical Engineering Department Intake stroke: Plunger moves up, vacuum is created in the cylinder, suction valve opens and liquid enters into cylinder. Discharge stroke: Plunger moves down, suction valve closes and delivery valve opens through which high pressure liquid is delivered to the delivery pipe. Chemical Engineering Department

Chemical Engineering Department Advantages Long life, reliable service Low pressure applications Can be made of multiple materials Self priming. No need to fill the cylinders Disadvantages Pulsating flow. The suction stroke is difficult when pumping thick liquids. Severe wear when handling fluids with suspended solids. Low volume rates of compared to other types of pump. Chemical Engineering Department

Chemical Engineering Department TYPE OF PUMP APPLICATION Piston pump For low head and more discharge Plunger pump For high head and less discharge, and for denser liquids. Multi stage centrifugal pump High discharge Multi stage centrifugal pumps For high head Rotary pump For viscous fluid like lubricating oil Chemical Engineering Department

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