project presentation 01

7/31/2019 Project Presentation 01

1/16

INDUSTRIAL DEFINE

PROBLEM

TRIPPING OF CONDENSAT

EXTRACTION PUMPSUBMITED BY:

PATEL MILAN D. 08ME444TAILOR JIGAR R. 08ME457PATEL BHAVESH 08ME436


2/16

INTRODUCTION

An extraction pump is an important part of a feed watersystem.Generally, fitted in between the condenser and de-aerator, the extraction pump works as an excellent tool forgenerating the requisite pressure, to deliver the feed waterfrom a condenser under vacuum to de-aerator or a feedpump inlet.

Extraction pump is usually a vertical shaft, two stage,centrifugal pump, which is used in applications involvinghigh pressure and high volume. Centrifugal pumps are ofthe type, which due to their high capacity, require a specificminimum suction head to operate.

Almost all the feed systems having an extraction pump, use

a condensate level controller system, which is attached tothe condenser and perform two main functions: To maintain the amount of condensate in the condenser To provide the sufficient suction head to the extraction

pump


3/16

Construction & working

A centrifugal pump, consists of three main parts - impeller,diffuser and volute casing.

A two stage centrifugal pump consists of two impellersarranged .The high temperature water, which is almostboiling due to the low vacuum condition, enters the firststage impeller from the suction line. The high temperaturewater receives slight positive pressure from the first stageimpeller and it then passes through the second stageimpeller. In the second stage impeller, water gets morepressurized, almost equal to the required system pressure.The pressurized water then passes through the diffuser,where the strategically arranged vanes pushes the water

towards the volute casing at an even higher pressure. Thevolute casing removes the water through the water outletat the appropriate system pressure.


4/16


5/16


6/16

The pumps are vertical multi-stage bowldiffuser type, arranged inside a suction

barrel. The condensate water is drawnfrom the condenser by the extractionpumps and sent to the low pressure feedheaters.

In the nuclear power plants, three pumpsare generally installed - two running andone in stand by. Variable speed drives arepossible and the pump is made to operatesafely and economically at full speed underpartial load conditions.


7/16

CE PUMPS EXPERTISE

The discharge column and pump head are made ofstrongly reinforced fabricated steel sheets, to ensure longlife, despite dif fi cult running conditions in nuclear powerplants The pump is fi tted with a balancing drum, par tly

compensating the axial thrust. A strong tilting pad typethrust bearing carries the remaining efforts Shaft bearings are journal type, lubricated by thepumped water. Impellers are equipped with renewablecasing wear rings The electrical motor is located on a separate civilstructure, avoiding interactions with the pumps andminimising vibrations The motor is equipped with its own thrust-bearing device


8/16

The excellent hydraulic featuresinclude

The double suction is located at the very bottom of the

pump in order to operate under the best possible NPSHconditions

The suction impeller has been specially designed andlaboratory tested to ensure the lowest required NPSH atall running points, which are always very severe

The pressure stages are located as close as possiblefrom the pump discharge head


9/16

Description and Design Features

BowlA diffuser with integral cast vanesSuction Bell / Bell MouthDesigned for smooth inflow of water with minimum losses

ShaftMade of high tensile strength steel

Column PipeFabricated column pipes to house the line shaft bearingsand direct the water from pump unit to the discharge

headTransmission BearingsCutless bearings are of natural rubber / synthetic rubber /elastomeric with outer shell of brass or suitable material


10/16

Thrust BearingsMitchell tilting pad type or anti-friction type for taking

hydraulic axial thrust and weight of rotor assemblyBearing lubrication with either oil or grease Thrustbearing arrangement available either independently inpump and drive or combined in drive

Discharge Head / Suction and Delivery Casing

Discharge head connects flow from suction pipe to CAN(outer shell) and directs the flow from pump unitthrough column pipe in to discharge line

CAN (Outer Shell)Fabricated CAN made out of steel is connected to the

discharge head. Length of the CAN depends upon theNPSHA at site

Non-Reverse RatchetNon reverse ratchet (optional) to prevent the reverserotation


11/16

Motor Stool

Rigid construction to endure vibration-free operationCouplingFor pump and prime mover flexible or rigid type asper requirement For line shaft threaded or muff typeas per requirement

DriveElectric motor with vertical solid shaft as standardarrangement Alternative thrust bearing housed in themotor

High Efficiency and Low NPSHR

Hydraulic design constantly being updated through ourresearch and development work meeting high efficiencyand low NPSHR requirements


12/16


13/16

DEFECT DETAILS:

Abnormal heavy sound coming from pump assembly

and high vibration issue due to this pump getstripped and thus the standby pump started working.

Due to this the pump was decoupled and at a time

of decoupling we found cooling water pipe was

busted many parts were broken shaft was damaged

with full scratches on it coupling was seen broken

from its welding


14/16


15/16

Due to heavy

vibration in

whole pump welded

joints

of the coupling

were shearedoff /broken off

thus we have

to replace that or

to repairit by doing welding

it again.


16/16

project presentation 01

Documents