summer training report for indian rare earth limited oscom
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Indian rare earth limited
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TABLE OF CONTENTS
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Indian rare earth limited
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
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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Indian rare earth limited
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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