Nrl training group 2

PUMPS USED IN PUMPS USED IN REFINERIESREFINERIES

Presenting by-

Hirok Jan Barman Hirok Jan Barman (133)(133)Saurav Konwar Saurav Konwar (056)(056)Saifuddin Mirza Ahmed Saifuddin Mirza Ahmed (109)(109)Deepak Dolakashoria Deepak Dolakashoria (107)(107)Rijuan Hussain Rijuan Hussain (134)(134)Lakshi Nandan Borah Lakshi Nandan Borah (140)(140)Feroz Ahmed Mazumder Feroz Ahmed Mazumder (017)(017)

for the training seminar done at -

Don Bosco School of TechnologyDon Bosco School of Technology11..

Introduction to NRL…..Introduction to NRL…..

Hydraulic Pumps…..Hydraulic Pumps…..

Sealing's used for pumps….Sealing's used for pumps….

Anti-friction & Journal bearings…..Anti-friction & Journal bearings…..

Flow controllers….Flow controllers….

Distillation units….Distillation units….

Dismantling techniques….Dismantling techniques….

A Case Study…..A Case Study…..Wednesday, May 3, 2023

2 ContentsContents

1. Proposal for Refinery included in “Assam Accord” : August 15, 1985

2. “NUMALIGARH REFINERY LIMITED” incorporated : April 22, 1993

3. Commercial Production commenced : October 1, 2000

4. NRL became subsidiary of BPCL : March 31, 2001

5. BHARAT PETROLEUM CORPORATION LIMITED (BPCL)BHARAT PETROLEUM CORPORATION LIMITED (BPCL), GOVT. OF ASSAMGOVT. OF ASSAM & OIL INDIA OIL INDIA LIMITED LIMITED are the promoters of the company having equity participation of 61.65%, 12.35% & 26% respectively.

6. NRL is designed to process 3 million metric tonnes per annum (MMTPA) of indigenous crude oil.

Products of the major units of the Refinery are LPG, Naphtha, Aviation Turbine Fuel (ATF), Superior LPG, Naphtha, Aviation Turbine Fuel (ATF), Superior Kerosene Oil (SKO), High Speed Diesel (HSD), Calcite Petroleum Coke (CCU) and SulphurKerosene Oil (SKO), High Speed Diesel (HSD), Calcite Petroleum Coke (CCU) and Sulphur.

Wednesday, May 3, 2023

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INTRODUCTIONINTRODUCTION


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HYDRAULIC PUMPSHYDRAULIC PUMPS

Pump converts input power to kinetic energy using centrifugal force.

Pump makes to move a fluid bytrapping a fixed amount and forcing that trapped volume into the discharged pipe.

Consider a bottle containing water inside. Consider a bottle containing water inside. Figure - 1 If we make a hole at the bottom of bottle, then the water will If we make a hole at the bottom of bottle, then the water will

come out of the bottle.come out of the bottle. Now, if we rotate the bottle at some speed, then the water Now, if we rotate the bottle at some speed, then the water

flow rate will increase, that is water will come out faster from flow rate will increase, that is water will come out faster from bottle.bottle.

This phenomenon is used in This phenomenon is used in Centrifugal pumpCentrifugal pump. . Figure - 2

The two main parts of the pump are the impeller and the The two main parts of the pump are the impeller and the diffuser.diffuser.

Impeller, which is the only moving part, is attached to a shaft Impeller, which is the only moving part, is attached to a shaft and driven by a motor. and driven by a motor.

The diffuser (also called as volute) houses the impeller and The diffuser (also called as volute) houses the impeller and captures and directs the water off the impeller.captures and directs the water off the impeller.

Impellers are of 3 types- Impellers are of 3 types- Open, Semi-open & Closed.Open, Semi-open & Closed. Wednesday, May 3, 2023

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CENTRIFUGAL PUMPCENTRIFUGAL PUMP

Figure-1Figure-2

Figure-3


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Different parts of Centrifugal pumpDifferent parts of Centrifugal pump

1. Single suction 1. Single suction pumppump2. Double suction 2. Double suction pumppump3. Over hanging 3. Over hanging pumppump4. Between Bearing 4. Between Bearing pumppump5. Single stage 5. Single stage pumppump6. Multi stage pump6. Multi stage pump

Different classifications Different classifications are-are-


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Working of centrifugal pumpWorking of centrifugal pumpWater enters through impeller eye impeller eye and exits the impeller impeller with the help of centrifugal force.As it leaves the eye a low-pressure area low-pressure area is created, causing more water to flow into the eye.Velocity is developed as the water flows through the impeller spinning at high speed. The water velocity is collected by the diffuserdiffuser and converted to pressure by specially designed specially designed passageways that direct the flow to the discharge of the pump.A centrifugal pump is not positive actingnot positive acting; it will not pump the same volume always.Since the pump is a dynamic device, it is convenient to consider the pressurepressure in terms of head i.e. meters of liquid column.meters of liquid column.


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Cavitation & NPSHCavitation & NPSH(Net positive suction head)

☻Liquids can vaporizevaporize at very low temperature when they are subjected to low pressure.☻Pump cavitations Pump cavitations occurs when the pressure at pump inlet drops below the vapour pressure of the liquid.☻It is sudden formation and collapse of low pressure of low pressure bubbles bubbles in the liquid caused by the continuous rotation of the impeller, that forms high velocity jets high velocity jets & impinges on impeller.☻Due to this impact there is a metal removal processes metal removal processes from the impeller, which causes noise, vibration, and damage to pump’s internal components.

☻Vaporization of liquid being pumped must not occur at any condition as when liquid vaporizes its volume increases very much, & less water is pumped.☻Any decrease in external pressure or rise in operating temperature can induce vaporization and the pump stops pumping, so pump always needs to have sufficient amount of sufficient amount of suction headsuction head to prevent from vaporization.☻NPSHNPSH as a measure to prevent liquid vaporization.


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Net positive suction headNet positive suction head֍ NPSH Available (NPSH Available (NPSHA): ): The available total suction head at the pump inlet above the head corresponding to the vapour pressure.֍ NPSH Required (NPSH Required (NPSHR): ): The minimum pressure required at the suction port of the pump to keep the pump free from cavitations.֍ NPSHA is a function of your system and must be calculated, whereas NPSHR is a function of the pump and must be provided by the pump manufacturer.֍NPSHA must be greater than NPSHR for the pump system to operate without cavitations.֍Net positive suction head available is calculated from-


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Characteristics CurveCharacteristics Curve♠ API 610 (American Petroleum Institute) API 610 (American Petroleum Institute) offers guidelines for pump selection that will run uninterrupted for a minimum of 3 years and provide minimum 20 years of reliable service. A typical API 610 pump performance curve looks like this :-♠ Every pump has a Best Efficiency Point (BEP) which is the flow at which it is operating at its highest efficiency.♠ Rated flow is located between 80% -110% 80% -110% of BEP. It is a point the customer chooses to rate the pump.♠ Preferred operating region should be between 70% - 120% 70% - 120% of the BEP, this is where the pump is expected to operate under normal conditions.

♠ Best Efficiency Curve looks like this :-♠ Min flow Min flow is the minimum flow below which the pump should not be operated otherwise it could be in danger of premature failure.♠ Minimum continuous stable flowMinimum continuous stable flow, set by the manufacturer as the lowest flow at which the pump can operate without exceeding the vibration limits imposed by API 610.♠ Minimum thermal flow Minimum thermal flow is defined as the “lowest flow at which the pump can operate without its operation being impaired by the temperature rise of the pumped liquid.

a) Always recommended to maintain minimum continuous flow, or bypass/recirculation line is used for flow less than minimum continuous flow.

b) Where, a separate pass line is used with a valve connection to separate the fluid, given based upon how much discharge is required.


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RECIPROCATING RECIPROCATING PUMPPUMP►A reciprocating pump is a class of positive displacement positive displacement pump pump which includes the piston pump, plunger pump and diaphragm pump.

►Often used where a relatively small quantity of fluid is to be handled and where delivery pressure is quite large. Specially for Specially for viscous fluidviscous fluid.

►The fluid sucked is pushed due to the thrust exerted on it by the moving member, which results in lifting the liquid to the required height.

►The motion of these parts are mating with a cavity or cavity or chamber chamber and the contact is leakage proof.

►During one direction of motion of the reciprocating part fluid is taken inside and during the other opposite direction of motion of fluid is pushed out.

►Different components of a reciprocating pump are as follows-

1.1.Cylinder, Piston/Plunger, Crank/Connecting rod.Cylinder, Piston/Plunger, Crank/Connecting rod.

2.2.Suction/Delivery pipes & valves, Air-vessel.Suction/Delivery pipes & valves, Air-vessel.


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Working of the pumpWorking of the pump۩ In suction stroke, the pressure in cylinder decreases and fluid enters into the chamber, suction valve then opens and allows the fluid to enter the cylinder and closes at the end of the stroke.

۩ In discharge stroke, the fluid enters the discharge pipe as pressure in the discharge pipe is less than in the chamber, this pressure enables the discharge valve to open and suction valve to close.

۩ These pumps are designed to do so once per cycle which is single acting and, if it does twice per cycle then it is called a double acting.

۩ A single acting displaces fluid only in one direction, but a double acting pump displaces in two directions in twice stroke.

۩ When the water in delivery pipe is delivered with greater speed than the average, then the excess amount of water is stored in the air vessel which contains air & gets compressed as the water enters the vessel.

۩ The stored water comes out when the delivery flow becomes less and thus a continuous flow is maintained.

۩ For a continuous flow of liquid these air vessels are used.


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SCREW PUMPSCREW PUMP۞ It is a positive displacement pumppositive displacement pump that use one or more screws to move fluids or solids along the screw axis screw axis the screw pumps are used for pumping high viscous fluidsviscous fluids.

۞ The fluid is sucked from the suction nozzle and then through linerliner, the fluid is entered into the screw.

۞ As the screw rotates at high speed, it creates a pressure difference. Due to which fluid enters into the screw gaps and with the rotation of the screws, the fluid is send to the discharge nozzle.

۞ Depending upon number of screws, they are :-

1. Single screw pump- one screw is used to pump fluid from one place to another. (Figure-1)……(Figure-1)……

2. Double screw pump- two screws fitted with intermeshing there screw threads, used to pressurise fluid and move them in a system. (Figure-2)……(Figure-2)……

Figure-1Figure-2


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SEALING’S USED IN SEALING’S USED IN PUMPPUMPGLAND PACKING GLAND PACKING - Old fashioned technology, using soft packing of ropes compressed by a packing gland.

Actually how it Actually how it looks and looks and packing is done.packing is done.

After this came the use of After this came the use of Mechanical seals……Mechanical seals……


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The mechanical sealThe mechanical seal The most effective method of preventing the leakage of the fluid from pump to the external surroundings is by using the mechanical seals.mechanical seals.

The mechanical seals helps sealing the rotating part of the shaft against the stationary part of the pump housing.

The different designs available, for the mechanical seals configuration. They are :-

1. Pusher2. Non pusher3. Cartridge


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What & How Mechanical seals?What & How Mechanical seals?͏ PrimaryPrimary & & Secondary seal.Secondary seal.͏ One component is stationarystationary and the other rotatesrotates against it to achieve a seal.͏ One of the faces is usually a non-wearing materials such as carbon-graphite carbon-graphite & other face is relatively hard material like silicon-carbidesilicon-carbide or ceramics.͏ There are at least three forces three forces trying to open the seal faces :-͏ If the closing forces are the greater forces, the seal will generate heat that is often destructive, but always a waste of energy and pump efficiency.͏ If the opening forces are the greater forces the seal will leak and that’s never desirable.͏ Most of the refineries maintain the standard ratio standard ratio :-

͏ Opening force is always slightly greater so that small Opening force is always slightly greater so that small amount of fluid can enter the faces as the lubricating fluid.amount of fluid can enter the faces as the lubricating fluid.

Seal with Seal with leakageleakage


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BEARING’S BEARING’S Mostly steel (300 °C), brass (250 °C), polymer (70 °C) within these operating temperatures are used.

Bearings are classified as anti friction and journal bearings.

1.Ball bearings1. Deep grove ball bearing2. Angular contact ball bearing

2.Roller bearings1. Cylindrical roller bearing2. Spherical roller bearing3. Tapper roller bearing

3.Thrust bearings4.Journal bearings (high speed bearings)


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Design aspects of Cylindrical bearingDesign aspects of Cylindrical bearing

NUP – outer ring has two flanges & inner ring has one flange.

NU – outer ring has two integral flanges inner ring has no flanges.

N – inner ring has two integral flanges outer ring has no flanges.

SERIESSERIES


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Bearings positioning used in pumpBearings positioning used in pump

☻ In centrifugal pumps, 2 angular 2 angular contact bearingscontact bearings & a roller contact a roller contact bearings bearings used.☻ A sight glass sight glass is used for visual monitoring of the bearing oil level.☻ The angular contact bearings are used in back to back arrangementsback to back arrangements. So, large load area.☻ In such arrangement the axial and axial and radial loads are restrictedradial loads are restricted in both the directions.☻ The roller bearing allows the The roller bearing allows the axial movement of the shaft, due to axial movement of the shaft, due to increased in temperature.increased in temperature.


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VALVES / VALVES / CONTROLLERCONTROLLER A valve is a device that controls & regulates controls & regulates the flow of a fluid or gasesthe flow of a fluid or gases, by enabling the opening or closing the valves. Valves are either controlled by hand or operated automatically. Different types of valves are :-

1.1. Ball valve- Ball valve- with hole in between is used for control of flow. A hollow circular ball is used in this case. If the ball is close, then we need to move it by 90° to open the valve.

2.2. Gate valve- Gate valve- In gate valve, the valve is in the form of a gate. The opening or closing of the valve is done by a screw and nut like arrangement. If we rotate the nut, the screw portion will come upward making the gate open.


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֍ Valves or ControllersValves or Controllers3.3. Globe valve- Globe valve- Glove valve is used for

controlling the flow rate. It is designed in such a way that, the flow rate can be controlled. The flow takes a zigzag path for travelling. We can partially open or fully open the valve as per our requirements.

4.4. Check valve- Check valve- Check valve is a non returning valve, which is used in the discharge pipe for a pump. It is so designed that it controls the back flow of fluid in the discharge pipe. In reciprocating pumps this type of valve is used in suction and discharge valve, for controlling the back flow of liquid. It is also called NRV (Non- Returning Valve).

5.5. Butterfly valve- Butterfly valve- A circular closed plate type is used for controlling flow. The plate is restricted in on direction and opens or closes with the fluid pressure.


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DISTILLATION DISTILLATION PROCESSESPROCESSES

Crude oil stored in the tanks.

Passed to the closed pressure vessels.

Then to the De-Salter.

Flowed to the heat exchangers.

Allowed to pass through furnace.

Then entered to the distillation column.

Crude Distillation UnitCrude Distillation Unit


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Distillation Distillation ProcessesProcesses

Reduced pressureReduced pressure//Vacuum Distillation UnitVacuum Distillation Unit

760 mm of Hg

760 mm of Hg

100 mm of Hg

100 mm of Hg

We know,

PVPV==nRTnRT

The feed is distilled in the The feed is distilled in the VDU.VDU.

&, thus at very low &, thus at very low temperature the compounds temperature the compounds are distilled. are distilled.


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DISMANTLING PROCESSDISMANTLING PROCESSof a Centrifugal pump….of a Centrifugal pump….

1)1) Disassembling the Pump- Disassembling the Pump- casing. Impeller locknut, impeller, back plate, mechanical seal (inspection).

2)2) Pull out the bearing from the Pull out the bearing from the Shaft-Shaft-

3)3) Inspection and Repair- Inspection and Repair- (check every possible gaps)

4)4) Recondition/Replacement of Recondition/Replacement of Parts-Parts-

5)5) Assembling the Pump-Assembling the Pump-

1) Lateral or Axial Movement of shaft (End Play)-(End Play)-

2) Radial Movement of shaft (Whip or (Whip or deflection)-deflection)-

3) Shaft Run Out (Bent (Bent shaft)-shaft)-


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☻ OUR CASE STUDYOUR CASE STUDY

AFTER IMPELLER DISMANTLING -1. Impeller wear ring outer diameter = 124.7mm124.7mm.2. Casing wear ring inner diameter = 125.22mm125.22mm..So, the clearance is = 0.520.52. This clearance is acceptable as minimum requirement is = 0.60.6..

Our inspection of a Centrifugal pumpOur inspection of a Centrifugal pump….….

OBSERVATIONS :-OBSERVATIONS :-1. Bearing housing cover is rusted.2. Service fluid found inside sleeve.3. Service fluid and rusting found inside mating parts and rusting found inside rings.4. Metal removal is found in the between shaft sleeve and stuffing box sleeve.5. Seal ring found broken.


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Our case studyOur case study

AFTER SHAFT DISMANTLING -AFTER SHAFT DISMANTLING -1. Radial play = 0.2mm0.2mm, ((not acceptable…..) not acceptable…..) 2.Radial run out = 0.02mm. 0.02mm. 3. Axial play =

0.05mm0.05mm

AFTER BEARINGS DISMANTLING-AFTER BEARINGS DISMANTLING-1. Bearing outer diameter = 89.98mm89.98mm.2. Bearing housing inter diameter =

90.04mm90.04mm.3. So, clearance is 0.06mm0.06mm (not

acceptable…)4. Bearing inner diameter = 39.98mm39.98mm.5. Shaft diameter= 40.00mm40.00mm.6. So, the interference is = 0.02mm0.02mm

(acceptable….)1. Bearing thickness = 55.50mm (combining)

2. Housing depth = 45.96mm.3. Cover depth = 9.5mm4. So, (45.96 + 9.5 = 55.46mm), but the

bearing thickness is 55.50mm, thus interference is 0.04, (acceptable….).

CONCLUSION :-CONCLUSION :-1. New bearing housing is used.

2. New shaft is used.

3. Bearings are changed.

4. Mechanical seal ring part is changed.

Wednesday, May 3, 2023Wednesday, May 3, 2023

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CONCLUSION……

T H A N K

‘U’


EVERY ONE

Nrl training group 2

Education

Transcript of Nrl training group 2