internship reprt

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InternshipReport

July 15

2011 The internship was not project based rather it was more oriented towards

learning functioning and purposes of the equipment used in the company.

The internship constituted of studying about heat exchangers, steam

turbines, centrifugal pumps, glass level gauges and different

manufacturing processes used in the factory. Each component was taught

in detail. Both the parts and the function of each part and the assembly

was studied in detail. Following is a comprehensive summary of different

types of equipment studied in different areas of the company.

FaujiFertilizer

Company



CONTENTS

Executive Summary ....................................................................................................................................... 3

Utilities (Mach 1) ........................................................................................................................................... 4

Target ........................................................................................................................................................ 4

TP601 ............................................................................................................................................................ 4

Overview ................................................................................................................................................... 4

CONSTRUCTION AND OTHER DETAILS ...................................................................................................... 4

Casing .................................................................................................................................................... 4

Internal details ...................................................................................................................................... 4

Maintenance ......................................................................................................................................... 5

P601 .............................................................................................................................................................. 5

Construction .............................................................................................................................................. 5

Summary ................................................................................................................................................... 5

Fabrication Shop ........................................................................................................................................... 6

Machine tools and facilities ...................................................................................................................... 6

Heat exchangers........................................................................................................................................ 6

Construction .......................................................................................................................................... 6

Welding Technology.................................................................................................................................. 7

Planning and Scheduling ............................................................................................................................... 7

Turnaround planning and scheduling ................................................................................................... 7

SAP ........................................................................................................................................................ 7

Machine Shop ............................................................................................................................................... 7

DSTK-4431 AND K-4431 ................................................................................................................................ 8

K-4431 ....................................................................................................................................................... 8

DSTK-4431 ................................................................................................................................................. 8

E4213 ............................................................................................................................................................ 9

Glass Level Gauges (GLG’S) ........................................................................................................................... 9

transparent level gauges ........................................................................................................................... 9

reflex level gauges..................................................................................................................................... 9

Bicolor GlG’s ............................................................................................................................................ 10



Graduated Cylinder Glass Level Gauges ................................................................................................. 10

magnetic glass level gauges .................................................................................................................... 10

E123 ............................................................................................................................................................ 10

Valves .......................................................................................................................................................... 10



EXECUTIVE SUMMARY

The internship was not project based rather it was more oriented towards learning functioning and

purposes of the equipment used in the company. The internship constituted of studying about heat

exchangers, steam turbines, centrifugal pumps, glass level gauges and different manufacturing

processes used in the factory. Each component was taught in detail. Both the parts and the function of

each part and the assembly was studied in detail. Although it is enough to mention the working of the

different equipment only but due to difference in the constructions and way of handling the process, I

define individually, the working and construction of equipments in different areas. Following is a

comprehensive summary of different types of equipment studied in different areas of the company.



UTILITIES (M ACH 1)

Target

TP601

P601

TP601

Overview

TP601 is a backpressure impulse type turbine. A backpressure turbine is a turbine in which the exhaust

pressure is equal to or higher than the atmospheric pressure. Nomenclature of this turbine represents

that this turbine is driving a pump.

CONSTRUCTION AND OTHER DETAILS

Casing

Steel casing encapsulates all the internal parts of the turbine. It has two halves. Upper half can be

removed for inspection and maintenance without disturbing the lower half.

Internal details

The turbine is a six stage turbine having a single row of buckets in the single rotor of each stage. Dovetail

base provides base to the buckets where they are to be fixed in. Each of the six wheels are shrunk and

keyed on the shaft. Shroud bands are provided on the buckets to prevent the spilling of the steam.Most of the details of the turbine are the same as listed in the general description of the steam turbines

in the API (books taught in the internship). The carbon as well as the labyrinth seals is used to prevent

the leakage of steam and oil respectively.

Two sleeve bearings (journal bearings) are used for supporting the shaft. The two main bearings

designated as the steam end bearing and the exhaust end bearing. They support radial load. Stops are

used to prevent the bearing to rotate with the shaft. The axial motion of the shaft is resisted by two

collars which act as thrust bearing. Oil at 1.5 bar is provided to all the bearings and the parts needing

lubrication.

Speed control is achieved by Woodward type governor. Governor drive shaft driven by a worm gearthrough a bronze gear is sensing the speed of the turbine due to which the flow of the steam in the

nozzles is controlled.

EMERGENCY OVERSPEED TRIP AND LOW OIL PRESSURE TRIP is achieved by a weight acting centrifugally

on trip finger to stop the flow of the steam to the rotors, in order to protect the turbine from damaging.



Maintenance

For shutting the turbine down, the steam inlet is closed first and the exhaust is closed next. For starting

the turbine, the exhaust valve is opened first and then the inlet is opened. This is done to avoid the

buildup of unnecessary pressure. For avoiding bow, necessary precautionary measures are taken. For

shutting down, the usual practice is to use the tripping mechanism.

P601

As the nomenclature suggest, P601 is driven by TP601. The pump is a high pressure centrifugal, boiler

feed water pump.

SUCTION TEMPERATURE: 110/110/135 (20 OC @startup). SUCTION PRESSURE: 2.27 min & 7.04

maximum. DISCHARGE PRESSURE: 146 (normal). SPEED (RPM): 2980.

Construction

It is a multistage pump having 8 stages. It has radially split casing. The casing consists of the suction and

discharge casing and a number of stage casings. The casing components are sealed off against one

another by ground metal-to-metal sealing faces, and are clamped together by tie bolts. O rings are used

to seal off the stuffing box housings. In order to achieve a favorable net positive suction head (NPSH)

requirement as possible, the suction nozzles are sized two nominal sizes larger than the discharge

nozzles.

Balancing device is used in this pump to compensate the axial thrust which sets in the direction of the

suction end of the unbalanced differential area of the impellers, which is due to the sealing diameter atthe sealing diameter at the impeller hub. The balance disc seat is firmly fastened in the discharge casing.

any wear which occurs on the balancing device is indicated on the rotor (axial) position indicator

attached to the pump stub shaft at the discharge end.

Shaft is protected against the aggressive action of the fluid pumped by sleeves and spacer sleeve. The

stage sleeves also serve to locate the impellers axially on the shaft.

As discussed above, most of the function of this pump is the same as usual centrifugal pumps. Above

was the crux of what I learned studying P601.

Summary

8 stage centrifugal compressor.

Boiler feed water pump.

Mechanical seals used where required, as in TP-601.



Pass Partition

F ABRICATION SHOP

Machine tools and facilities

Following are some of machine tools and facilities that are present in the fabrication shop of FFC.

Hot tapping machine (used to make holes in fixed tubes/pipes).

High pressure jetting machine (used for providing pressurized water to cure fouling).

Welding generators and machines.

Hydraulic pumps (used for providing pressurized water for checking leakage).

Magnetic drilling machine.

Pulling machine (Machine for pulling out exchanger tubes).

MINI C (Machine used for facing and other operations on the tubes).

Heat exchangers

For heat transfer between different fluids, heat exchangers are used everywhere in this industry. Thereare different types of heat exchangers used. Most of the heat exchangers used are shell and tube heat

exchangers.

Construction

Following are some main components of a heat

exchanger.

Bonnet, Shell, Tube Sheet, Channel,

Channel Baffle, Channel Cover, Tube Bundle,

Connections.

The tubes are either welded or fastened in

a mechanical

way to the tube sheets. Baffles are installed to

support the tubes. Baffles are segmented sometimes to

change the direction of flow as well as to increase the

stay time of the fluid on the tubes. The size of the heat exchanger is designated in the format:

(Shell inner diameter) X (length of tube)

The heat exchanger tubes can be fined or unfinned. There are different arrangements of the tubes forefficient heat transfer.

The fins can be internal or external. For prolonged use of the heat exchanger, fouling occurs in the heat

exchangers on the shell and the tube sides. Different chemical and mechanical processes are used to

remove the sediments from the shell and tube.



carry out the machining. Machining capability of the large vertical lathe machine is 1600 x 1200 mm

(diameter x height). In all the machines, tools with sharp cutting edges are used to remove the material

for the required purpose. There are almost 34000 tool pieces in the tool room which are issued daily for

use in the factory. Total of 5000 kinds of tools are present.

The purpose of vehicle shop is to provide moving vehicles to the factory for different factory uses and it

is the duty of maintenance department of the vehicle shop to maintain the vehicles. Vehicle shop has

heavy duty cranes as well as lifters and other vehicles for factory use.

DSTK-4431 AND K-4431

As the nomenclature suggests, the compressor K4431 is driven by steam driven turbine DSTK-4431.

These two machines are assembled such that the turbine DSTK4431 is present in between the two

stages of the compressor namely: HP and LP. The whole assembly of the turbine and the pump is called

syn-machine because it is able to handle mixture of different gases.

K-4431

There are two stages of the compressor: Low pressure and high pressure. The low pressure stage has 8

impellers with two inlets and two outlets. In one stage, fluid entering the compressor from the inlet,

exits after passing through four rotors and after cooling enters the next four rotors for completing low

pressure compression. After low pressure compression, the fluid being compressed enters the high

pressure compressor having 9 impellers which also has two inlets and two outlets. The fluid mixture is

transferred from one impeller to the other by means of channels which guide the fluid mixture.The

construction of this compressor is the same as the centrifugal pumps. The energy from the steam

turbine turns the rotor of the compressor which increases the speed of the fluid by forcing the fluidcentrifugally towards the exit where the dynamic pressure head is converted to increase the static

pressure head. Each rotor is separated by means of a diaphragm which has diffusers in it for the

conversion of dynamic pressure head to static pressure head (increase). Balancing drums and spacers

along with the thrust bearing are used to control the axial thrust of the rotor. Common seal used in the

compressor is the labyrinth seal and ring seals. Balancing drum is used to balance the axial thrust

produced by the pressure difference.

DSTK-4431

This turbine is used to drive the compressor K-4431. The construction is very similar to all the other

turbines. Stainless steel with 14% chromium is used for the manufacturing of the turbine blades. Theturbine has 3 numbers of stages for expansion of steamThe three stage turbine has three impellers

which are mounted on a shaft which in turn is mounted in casing by means of journal bearing. All other

parts for other functions like thrust balancing etc. are also present in this turbine.



E4213

This heat exchanger exchanges heat between the process gas and boiler feed water. The BFW is on the

tube side. This is a 2 shell and 4 tube pass heat exchanger. The diameter of the tube is ¾” and that of

tube inner side is 1365 mm. There are two inlets in each shell. The fluid enters the upper shell and

leaves the lower shell. Vents are provided in the inlets and the outlets which are opened when the

operation of HE stops so that the gases present in the heat exchanger escape. The shell side fluid enters

the lower shell tubes from one side and leaves the same shell on the same side and then enters the

lower side of the upper shell. The tube bundle is U-tube. The saddle supports both the shells. 8000 mm

is the useful length of each tube. The working temperature of the shell side is 300oC and that of the

tube side is 276oC. Segmented baffles are used to direct the flow on the shell side and support the tube

bundle.

GLASS LEVEL G AUGES (GLG’S) Glass level gauges are vertical gauges with its bottom end connected to the bottom of the equipment

and the top end connected to the top end of the equipment. According to archemidius principle, the

level in the equipment is shown by the glass level gauge. There are five types of glass level gauges.

1. Transparent level gauges

2. Reflex glass level gauges.

3. Bicolor glass level gauges

4. Graduated cylinder glass level gauges

5. Magnetic glass level gauges.

transparent level gauges

These gauges are simple glass columns with no graduations. The level in the gauge tells the level in the

equipment.

reflex level gauges

Reflex level gauge consists of an enclosure with a glass in its opening. The front end of the glass is facing

the user and the other end, which is serrated, is exposed to the fluid whose level is being measured.

Light entering the open end tries to penetrate inside towards the fluid. The design of the serrations are

such that the refractive properties of the serrations only allow light to enter into the fluid while does not

allow the light to enter where the space is empty. The light that enters the fluid does not gets out of thegauge because the design allows the phenomenon of total internal reflection and hence only the portion

of the level gauge where there is fluid seems dark and the portion which is empty looks brighter. And

hence the level of the fluid is the dark portion of the gauge.



Bicolor GlG’s

It consists of a trapezoidal extrusion with holes on two equal sides of the solid. The holes has such

coverings which only allow two wavelengths of light to pass through. These two wavelengths are Red

and Green. When there is a liquid level in the gauge, the refractive angle of the green light is such that

total internal reflection does not allow the green light to escape from the portion where there is liquid,and the liquid portion seems red. The portion where there Is steam looks green because of the same

phenomenon.

Graduated Cylinder Glass Level Gauges

This is a simple glass column with graduations on it which show the level of the liquid in the equipment.

magnetic glass level gauges

This glass level gauge consists of a column of pivoted small magnets which is in contact with the liquid

column. The liquid column has a magnet in it on the surface. When the level of the liquid changes, the

motion of the single large magnet on the surface forces the small pivoted magnets to rotate, such that

the portion of the liquid level from which the large magnet has travelled, has one pole (S/N) pointing

towards it. The pivoted magnets above that level are facing the opposite pole. In this way the different

orientation of the colored poles allow the user to see different color for different level of the liquids.

E123

This heat exchanger is a turbine steam condenser

Since the heat exchanger is a condenser, so the body of the heat exchanger is elliptical. The shell is

made up of carbon steel. The heat exchanger is mill test certified.

V ALVES

A valve is a mechanical device which we use in a pipe line to regulate the flow of any fluid between two

points. A valve may be mechanically operated or operated by a pneumatic system or by using some

motors or chain sprocket system.

A valve can control the flow rate of fluid, Pressure differential of fluid across the valve

(Throttling phenomenon), Velocity of fluid and Temperature of the fluid. Following are the main types of

valves:

Gate valve, Globe valve, Check valve, Plug valve, Butterfly valve, Diaphragm valve.

Following are the few components of which a valve is composed of Body of valve, Bonnet , Seat

rings, Yoke , Stem , Obstruction to flow i.e. (gate, globe etc), Stuffing box, Hand wheel or lever,

Gland, Flanges , Gaskets , Nut and Bolts.

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