Summer Training Report for Indian Rare Earth Limited Oscom

Indian rare earth limited

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TABLE OF CONTENTS

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SL NO. TITLE PAGE NO

1. INTRODUCTION

2. Power supply system of IREL

i. MRSS

ii. LCSS

iii. MCC

iv. Safety aspects

3. Mineral Separation plant

4. Conclusion

Introduction:

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Indian Rare Earth Limited(IREL) was incorporated on august 18,1950 as a private

company jointly owned by the government of india and Travancore,Coachin.It became a

full fledged government of india undertaking under the administrative control of

department of atomic energy in the year 1963.However after a gap of 20 years ,IREL has

build its largest and integrated industrial complex known as OSCOM(Odisha Sand

Complex) near Matikholo about 8km south of Chatrapur,Odisha in the year 1984.

During my 25 days of vocational training at IREL ,I have visited Mineral Separetion

Plant,Main Receiving Sub Station,Load Control Sub Station and Machine Control

Centere and all of these are well planned and equiped with different material handling

materials and safety arrangements.

2. Power Supply System of IREL:

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Lay out of main receiving sub station(MRSS):

MRSS is designed to accomplish the following functions:

Change voltage from one level to another

Regulate voltage to compensate for system voltage changes

Switch transmission and distribution circuits into and out of the grid system

Measure electric power qualities flowing in the circuits

Connect communication signals to the circuits

Eliminate lightning and other electrical surges from the system

Make interconnections between the electric systems of more than one utility

Control reactive kilovolt-amperes supplied to and the flow of reactive kilovolt-

amperes in the circuits

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Major components of MRSS:

Feeders: Feeder circuits are the connections between the output terminals of a

distribution substation and the input terminals of primary circuits. The distribution feeder

circuit conductors leave the substation from a circuit breaker via underground cables,

called substation exit cables. The underground cables connect to a nearby overhead

primary circuit outside the substation.

Isolators: It is designed to open a circuit under no load. It isolates one portion of circuit

from another and is not intended to be opened while current is flowing in the line.

When we want service or maintenance of any substation or want to clear the fault, at that

time isolator is kept open and supply is interrupted.

Lightening arrester: A lightning arrester is a device used on electrical power systems to

protect the insulation on the system from the damaging effect of lightning. The typical

lightning arrester also known as surge arrester has a high voltage terminal and a ground

terminal. When a lightning surge or switching surge travels down the power system to the

arrester, the current from the surge is diverted around the protected insulation in most

cases to earth.

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Earthing:

Grounding Resistors are designed to provide added safety to industrial distribution

systems by limiting ground fault current to reasonable levels. They are usually connected

between earth ground and the neutral of power transformers, power generators or

artificial neutral transformers. Their main purpose is to limit the maximum fault current

to a value which will not damage generating, distribution or other associated equipment

in the power system.

Bus bar arrangements:

When a number of feeders are operating at the same voltage have to be directly

connected electrically, bus bars are used as the common components. Bus bars are copper

rods or thin walled tubes and operate at constant voltage.

Circuit breakers:

A circuit breaker is an automatically operated electrical switch designed to protect an

electrical circuit from damage caused by overload or short circuit. Its basic function is

tom detect a fault condition and by interrupting continuity to immediately discontinue

electrical flow.

Air circuit breakers are used to interrupt circuits while current flows through them.

Compressed air is used to quench the arc when the connection is broken.

Oil circuit breaker: This employs some insulating oil for arc extinction

Vacuum circuit breakers: in which vacuum is used for extinction

Relays:

A relay is the device which detects the fault and supplies the information to the breaker

for circuit interruption.it can be divide into three parts.

The primary winding of acurrent transformer which is connected in series with the circuit

to be protected.

The second circuit is the secondary winding of c. t. conneced to the relay operating coilk.

The third circuit is the tripping circuit which consists of a source of suuply trip coil of

circuit breaker and the stationary contacts.

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Feeder circuit:

Isolator: lightning arrester:

:

Bus bar arrangements: relay:

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Circuit breakers:

Air circit breaker oil circuit breaker vacuum circuit breaker

Transformers:

It is an electrical apparatus for converting electrical power in an ac system from one

voltage level to some other voltage level at constant frequency.

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CTs & PTs: current transformer and potential transformers are used for metering

purpose and billing in industries with suitable accuracy.

Auxiliary supply and batteries:

Auxiliary Supply & Batteries are used in the substation control house as a backup to

power the control systems in case of a power blackout.

Capacitor bank:

Capacitors are used to control the level of the voltage supplied to the customer by

reducing or eliminating the voltage drop in the system caused by inductive reactive loads.

Control house:

The substation control house contains switchboard panels, batteries, battery chargers,

supervisory control, power-line carrier, meters, and relays. The control house provides all

weather protection and security for the control equipment. It is also called a doghouse.

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An Overview of Load Control Sub Station:

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Layout of motor control centre:

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Safety aspects:

Electric hazards:

Unlike other causes of accidents, electric energy is unseen so utmost care is needed to

save guard against electric hazards.

1% accidents are generally caused due to electricity but out of those total electric

accidents 40% are fatal.

Protection against electrical hazards

Proper wiring

All new, permanent or temporary electrical installations, or the replacement,

modification, repair or rehabilitation of any electrical installation must be made in

compliance with the requirements of the National Electrical code (NEC) of the National

Fire Protection Association (NFPA). Electrical power distribution systems must be

equipped with over current protection such as fuses or circuit breakers, which must never

exceed the rated capacity of the circuit. All newly installed receptacles must be of the

grounding type.

Grounding and bonding:

Grounding eliminates a difference in electrical potential between a conductive object and

the ground by connecting them. Grounding will protect you from electrical shock by

providing a path which offers less resistance to the current than you do. Bonding

eliminates a difference of potential between conductive objects. All exposed non-current-

carrying metal parts of fixed and portable equipment which are liable to become

energized must be grounded.

Insulation:

If you work continually with or around electricity, you should wear rubber-soled

footwear to guard against slipping and to provide insulation. Portable tools or appliances

protected by an approved (Underwriters' Laboratories) system of double insulation or its

equivalent need not be grounded. Where such a system is employed, the equipment must

be distinctly marked. Avoid using electrical equipment or tools where there is moisture

present. If it is unavoidable to do so, use ground fault circuit interrupters. Use a wooden

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or fiberglass ladder instead of a metal one, if work requires the use of a ladder around

electrical equipment.

Shock Treatment & First Aid

Electrical Shock

Electric shock occurs when the body becomes part of an electrical circuit. Shocks can

happen in three ways.

• A person may come in contact with both conductors in a circuit.

• A person may provide a path between an ungrounded conductor and the ground.

• A person may provide a path between the ground and a conducting material that is in

contact with an ungrounded conductor.

The extent of injury accompanying electric shock depends on three factors.

• The amount of current conducted through the body.

• The path of the current through the body.

• The length of time a person is subjected to the current.

Current in milli amperes Effects

1 or less No sensation; probably not noticed

1 to 3 Mild sensation not painful

3 to 10 Painful shock.

10 to 30 Muscular control could be lost or muscle clamping

30 to 75 Respiratory paralysis

75mA to 4 amps Ventricular Fibrillation

Over 4 amps Tissue begins to burn

An electrically safe work condition will be achieved and verified by the following

process:

1) Determine all possible sources of electrical supply to the specific equipment. Check

applicable up to date drawings, diagrams and identification tags.

2) After properly interrupting the load current, open the disconnecting device(s) for each

source.

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3) Where it is possible, visually verify that all blades of the disconnecting devices are

fully open or that draw out type circuit breakers is withdrawn to the fully disconnected

position.

4) Apply lockout/tag out devices in accordance with a documented and established

policy.

5) Use adequately rated voltage detector to test each phase conductor or circuit part to

verify they are de-energized. Before and after each test, determine the voltage detector is

operating satisfactorily.

6) Where the possibility of induced voltages or stored electrical energy exists, ground the

phase conductors or circuit parts before touching them. Where it could be reasonably

anticipated that the conductors or circuit parts being de-energized could contact other

exposed energized conductors or circuit parts, apply ground connecting devices rated for

the available fault duty.

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Mineral separation plant:

IREL is a pioneer in the field of processing beach sand minerals such as illuminate, rutile,

zircon, sileminite, garnet and monazite. These minerals are well categorized and

separated on the basis of their physical properties like electrical conductivity, magnetic

properties, specific gravity, and surface characteristics in mineral separation plant.

The production capacity of OSCOM is give below:

Illuminate: 220000tpa

Rutile: 7400tpa

Zircon: 5000tpa

Sileminite: 8000tpa

Monazite: 2350tpa

In addition to these there are two different plants New Thorium Plant (NTP) and

Zirconium Pilot Plant (ZTP).These plants have the capacity to produce the value added

products as thorium nitrate, thorium oxide etc.

the plant is comprised of different floors and is equipped with different material handling

materials like bucket elevators, belt conveyers, screw conveyers, drag conveyers to

facilitate smooth transport of materials to the desired machines via rotary dryers, high

tension separators, magnetic separators, shaft dryers, electrostatic plate separators etc.

besides these there is wet processing circuit comprising of spirals ,floater, wet tables and

slurry pumps to transport the materials from one point to another.

Uses of products:

Illuminate: manufacture of titanium dioxide pigments which is used in paints, papers,

rubber, textile etc.

Rutile: used for coating of wielding electrodes

Zircon: used in ceramics, refractory’s and manufacturing of zirconium alloys

Monazite: source of thorium and uranium in nuclear reactors and manufacture of thorium

nitrates

Sileminite: high temperature refractory and insulators

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Conclusion:

My practical ideas were enhanced after this industrial training in IREL

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Summer Training Report for Indian Rare Earth Limited Oscom