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NATIONAL FERTILIZERS LIMITED
(Naya Nangal Unit)
14th
May, 2015
CERTIFICATE OF TRAINING
Institutes name: Beant College of Engineering & Technology,
Gurdaspur (Pb)
Branch: B.Tech (Mech) 4th year
Training Period: January 15, 2015 to May 14, 2015
Submitted to: Submitted By: Ashish Kumar
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Contents
1. Introduction
2. Steam Generation Plant
3. Mechanical Workshop
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Introduction
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1.0 INTRODUCTION TO ORGANIZATION
A VIEW OF NATIONAL FERTILIZER LIMTED NANGAL
Figure 1.1 view of NFL NANGAL
1.1 INTRODUCTION TO NFL NANGAL
My training was at NFL Nangal. Nangal is a beautiful town
situated in Distt. Ropar (PB). This is
the first key industry set up by Govt. Of INDIA with coming up
of Bhakhra Dam & surplus
power available from the project at the time. It was derived by
Govt. Of India to set a fertilizer
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plant at Nangal, which went to production in 1961.The plant at
that time produce Ammonium
Nitrate (25% Nitrogen) and heavy water.
Subsequently In 1978 went an Ammonia Plant based on fuel oil
gasification which added Urea
(46% Nitrogen) to its main product in 1990.
In 1978, In urea formation the hydrogen was available from
electrolysis of the water which on
electrolysis treatment produce hydrogen and oxygen & from
this hydrogen further ammonia is
formed, but after short time of gap Electrolysis plant was
replaced with Front End Plant(NMP-I)
based on reforming of Naphtha production of hydrogen and
reducing the electrical power
consumption.
1.2 NFL PLANTS
NFL has several plants in all over India and the location of
various fertilizer plants In India as:-
1. National Fertilizer Limited Vijaipur (MP)
2. National Fertilizer Limited Panipat(HR)
3. National Fertilizer Limited Bathinda (PB)
4. National Fertilizer Limited Naya Nangal (PB)
1.3 PRODUCTS OF NFL
NFL Nangal mainly deals with production of Urea but there are
several by products which get
produce
Products Capacity( in MTPD)
Urea 1450
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Methanol 67
Sulphur 24
Ammonium Nitrate As per Reqd.
Liquid Carbon Dioxide 24
Sodium Nitrite 9
Sodium Nitrate 6
Nitric Acid 554
Ammonia 900
Table 1.1 products of nangal
There is also the formation of poisonous gases such as CO, CO2,
CH4, H2, & H2S etc.
The NFL, Nangal Unit has been broadly classified into two
parts:-
a) UGP ( UNIT GROUP OF PLANT):-
WTP - WATER TREATMENT PLANT
NAP- NITRIC ACID PLANT
urea
methanol
sulphur
Ammonium Nitrate
Liquid Carbon dioxide
Sodium Nitrite
Sodium Nitrate
Nitric Acid
Ammonia
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b) EGP (EXPANSION GROUP OF PLANT):-
SGP- STEAM GENERATION PLANT
UREA BAGGING PLANT
Statistic Data
The input and output data of company is as in which it informs
about the name of the
product and the consumption of raw material
Raw material Name of The
Product
Consumption
Fuel oil Ammonia 832.04 MT/Unit
Coal Steam 191.25 MT/Unit
Caustic Soda NOx 1547 MT/Annum
Water Consumption
River Satluj is the exclusive source of raw water to NFL, Nangal
unit.
1. Process Water (m3) for EGP 5538481
2. Process Water (m3) for UGP 307010
3. Domestic Water 4042120
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Raw water Analysis
S. No. Parameters Range Value
1. pH 7.8-8.0
2. Total Hardness (as CaCO3
mg/L)
29-34
3. Magnesium hardness, mg/L 4-6
4. Sulphates (as SO4 mg/L) 2-4
5. Chloride (as Cl, mg/L) 6-20
6. KMnO4 Value, mg/L 4-6
7. Calcium Hardness (as
CaCO3, mg/L)
46-52
pH
Total Hardness (as CaCO3
mg/L)
Magnesium hardness,
mg/L
Sulphates (as SO4 mg/L)
Chloride (as Cl, mg/L)
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1.4 COMPANY OUTPUT
Overall Turnover of NFL is 3800 crores.
The employee strength is as:
Total Employee 1542
Officers 232
Workers 1310
Main Product & its Objective:-
Kisan Urea Specifications:-
Moisture Less than 1%
Nitrogen on Dry Basis- More than 46%
Biurate by weight 1%
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Physical and chemical properties of urea:-
S.No. Property Assigned Value
1. Formula Weight 60.06
2. Melting Point 132.7oC
3. Boiling Point Decomposes at atmospheric
pressure (
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soil colloids for longer duration. Urea is available in granular
form and can be applied by
drill and broadcasting. Kisan urea is ideally suitable for all
types of crops and for foliar
spray which instantly removes nitrogen deficiency. Kisan also
has a strong and long
lasting effect on crops resulting in bumper crops. Carbonic acid
present in kisan urea help
in absorption of other nutrients like phosphate and potash by
roots crop.
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STEAM GENERATION PLANT (SGP)
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2.0 STEAM GENERATION PLANT
2.1 Objective of SGP:-
In NFL, Nangal Unit Plant, all the basic unit operations need
steam for their work and must of
the industrial equipment are driven by steam such as Turbo
Compressors, Steam jet ejectors,
preheater etc.
In unit operations
1) For evaporation supply the steam to evaporate
2) For crystallizations supply the steam to crystallizer
3) To create the negative suction pressure mostly supply in the
steam jet ejector
4) For combustions purpose such as gasification process
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5) To exchange the heat of desire product by use of steam.
SGP starts from-
1) Handling &Storage of Coal ,Fuel Oil ,LHSH , LDO &
Methanol
2) Boilers-
a) Coal Fired Boiler
b) Gas Fired Boiler
3) Pollutions Control Sections
4) Steam Network Section
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Figure 2. Unloading of coal
a) - COAL UNLOADING THROUGH TRIPLER
Tippler Wing Conveyor
Vibrators, ET-1(Underground)
(Cap. =550-600 MT/hr) ET-2 Coal Yard
ET-3
Coal Yard Storage Capacity = 30,000 Tons
b) - COAL FEEDING SYSTEM
Feeding Hopper Magnetic Belt
Vibrators Magnet Magnet
ET-4 (Underground) ET-5 ET-6
(Cap. =110-130 MT/hr)
Mill Bunkers (6 Nos.)
Coal from Wagon
Coal from Yard
Crusher
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2.2 COAL FIRED BOILER
2.2.1 INTRODUCTION:-
The integrated service boilers for the Nangal Expansion
Fertilizer Project are different from
conventional boilers. These boilers are radiant, outdoor,
bidrum, high head, non-reheated type &
pulverized coal is used as principal fuel
These boilers are designed to heat up external high pressure
saturated steam from heat boilers,
along with generated steam coal is used as principal fuel
These boilers are designed to heat up external high pressure
saturated steam from waste heat
boilers, along with generated steam in the boiler to the same
final superheated steam
These boilers generated 117t/hr of steam and 65t/hr external
import steam. The final superheated
steam generated 182t/hr will have a pressure of 91kg/cm2 &
temperature of 510
2.2.2 MAIN BOILER STRUCTURE:-
The boiler designed of the top supported type & allowed to
expand downwards. The main boiler
is supported four rows of column on either side of the boiler
(S1, S2, and S3 &S4)
Boiler feed water which is coming from NH3-II plant which is
preheated to 145 & then passing
through the economizer where its temperature is rises to 182-188
then it is transferred to the
steam drum. In the steam drum it is converted to the saturated
steam & remaining water is not
converted to steam is transferred to mud drum through bank
tubes
In the mud drum temperature of the condensed water is raises by
the flow of the flue gases from
the mud drum through bank tubes.
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In the mud drum temperature of the condensed water is rises by
the flow of the flue gases. From
the mud drum preheated water is then transfer through the tubes
along the sides of furnace and
recirculated to the steam drum and the above processes
continuously running. The purpose of
recirculation is that, we cant leave the steam drum empty.
The temperature of the saturated steam leaving the steam drum is
around 310 to 315C. The
saturated steam is then given to platin super heater where its
temperature is rises to about 405 to
410C. The temperature of the platen super heater is 905C
2.2.3 COAL PULVERSIZING SECTION;-
In this section ball mill is used to pulverize the coal. Firstly
coal which is crushed in the hammer
crusher to the size about size 25 mm is then transferred to the
coal bunkers & from coal bunkers
& from coal bunkers through feeder to the centre of
revolving ball of the ball mill. Hot air is
given to the Ball which is coming by passing through the air
heater for the following two
purposes:-
1. for the drying of the pulverized coal
2. for the movement of the pulverized coal to the furnace
Hot air enters the mill housing below the ball and is directed
upward passes through the classifier
vanes. The rising hot air around the ball picks up the
pulverized coal, the lighter particles carried
by the air passes through the classifier & heavier particles
are returned from the classifier to the
ball for additional grinding. Finally the pulverized coal having
particle size 200 meshes & air
leaves the Ball Mill through classifier
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2.2.4 COAL COMPOSITION
MOISTURE 6-10%
VOLATILE MATTER 16-20 %
FIXED CARBON 39-45%
ASH 30-35%
Table 2.1 coal composition
2.2.5 COMBUSTION CHAMBER OR BIOLER FURNANCE
At the four corner of the combustion chamber or boiler furnace
one wind box is installed. At
each corner one burner is located. Each burner will comprise of
four streams which are given to
the furnace, these are coal +Air, Tail Gas, LDO+ steam & hot
air nozzles arranged vertically in
an insulated wind box
Moisture
Volatile matter
fixed carbon
ash
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Air is sucked from the atmosphere by the forced draft fans &
supplied to the air heater. After
passing through the heater temperature of the air is increased
and then it is passed through the
heater temperature of the air is increased and then it is
transferred to the wind box. For the
burning of the coal oil gun is used & all the other streams
are given for the complete combustion
of the coal & unburned coal particles are dropped to the
bottom where screen is used to transfer
them to bottom ash hopper
The flue gases which are produced after the combustion of the
fuel moves upward to the furnace
with centrifugal force. Centrifugal force is developed when all
the streams from the four corners
will meet at a single where the burning is taking place
The temperature of the combustion chamber, where burning of the
coal is done is 1070C.
During the upward movement of the flue gas temperature
difference between lower and upper
part of the of boiler which is going to be in between 100C to
150C
2.2.6 TAIL GAS COMPOSITION
H2 7.00%
Ar 3.80%
N2 16.10%
CO 27.90%
CH4 3.30%
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H2O 41.90%
Table 2.2 tail gas composition
Tail gas which is coming out from ammonia II plant contains an
appreciable amount of CO
which is not directly disposed to the atmosphere because of its
harmful effects. So this gas is
ignite in the furnace and convert the CO to CO2 and reduced the
content of the gas
Due to the large content of non-combustion of gases i.e. N2
& H2O, the ignition of the CO gas is
difficult& is not self sustaining. After ignition is
converted to the flue gases and are disposed to
the atmosphere
2.2.7 PROCEDURE FOR DISPOSAL OF ASH:-
We used coal as a fuel for the running of the boiler,
approximate 1000MT/day of coal is used
and huge amount of ash is generated. For efficient running of
the boiler continuous removal of
H2
Ar
N2
CO
CH4
H2O
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ash contents is essential .Heavier particles of burned coal are
retained in the bottom ash hopper
of the boiler and the light particles are collected in the
Electrostatic Precipitator
Finally the mixture of ash & water is discharged through
feed gate & clinker, grinder, which
reduces the size of the clinker to about 50 mm to the ash slurry
pit. Then ash slurry is disposed to
ash pond area
2.2.8 BOILER FEED WATER SPECIFICATIONS:-
TEMPERATURE 145C
TOTAL HARDNESS AS CaCo3 0.3ppm
SILCA 0.1 ppm
O2 0.02ppm
IRON 0.02ppm
COPPER 0.005ppm
pH 7.5-9.0
Import steam which is coming from the NH3-II plant at a
temperature 313C and pressure105ata
is given to the import steam super heater where we get
superheated steam whose temperature is
around 510-520C. The temperature of the final super heater is
872C
For controlling the temperature of the superheated steam, one
desuperheater is used whose
temperature is ling in between 370-400C. So after desuperheater
finally we get superheated
steam whose temperature is 500C and pressure is 91 ata, which is
then given to different
sections in the plant. It produces 182 Ton/hr of superheated
steam.
The flue gas which leaves from the furnace is leaving at the
temperature of 530-540C, so
arrangement is made for the waste heat recovery. Firstly the
flue gases pass through import
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steam super heater where some amount of heat is recovered and
temperature of the flue gas
reduces to 430C.
Then it passes to economizer where the temperature is reduced to
338C and then it is passed
through air heaters which are used for preheating the air sucked
by forced draft fan the
temperature of the flue gases are sucked by force draft fans and
are given to the ESP for the
removal of fly ash or dust.
2.3 Main Boiler Structures
The boiler design of top supported type &allowed to expand
downwards. The main boiler
supported four rows of the column on either side of the boiler
(S1.S2, S3AND S4)
Boiler feed water which is coming from NH3-2 Plant which is
preheated to 125c &then passing
through the gilled tube economizer where temperature is rise to
182-188c then it is given to
steam drum & in the steam drum it is converted to saturated
steam.
The temperature of the saturated steam leaving the steam drum is
around 320-325c the water
which is remaining in steam drum is transfer through the tube
along the side of the furnace and
recirculated to the steam drum & the above process
continuously running .the purpose of
recirculation is that, we cant leave the steam drum empty .the
saturated steam is then given to
the platen super heater where its temperature rises to about
405-410c. The temperature of platen
super heater is 920c.
Import steam which is coming from the NH3-2 plant at a
temperature 313c and pressure 105 ata
is given to the import steam super heater where its temperature
is rises around 405 -410c.then
finally mix both stream i.e. saturated steam & import steam
&given to the final super heater
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from where we get superheated steam whose temperature is around
510-520c. The temperature
of final super heater is 872c.
For controlling the temperature of the superheated steam ,one
desuperheater is used to
whose temperature is lies in between 370-400c so after
desuperheater finally we get superheated
steam whose temperature is 510&pressure 91ata ,which is then
given then to different section in
the plant .it produces 140T/hr of superheated steam
The flue gas which leaves from the furnace is leaves from the
furnace is leaves at a temperature
of 660-670c ,so arrange is made for waste heat recovery .firstly
the flue gases pass through bare
tube economizer and then from import steam superheater where
some amount of heat is
recovered &temperature of flue gas reduced to 360c
Then it is passes through gilled tube economizer where
temperature is reduced to 299c 7 then it
is passed through rotary air heater is 121c
The flue gas after passing through rotary air heater is going to
the chimney & from the chimney
it is disposed to atmosphere the height of the chimney is 80m
&flue gas from other source of the
plant are also disposed from the same chimney the flue gas which
is disposed to atmosphere with
following compositions (SO2=500-600mg/Nm3, SPM=110mg/Nm3)
2.4 POLLUTION CONTROLL SECTION
2.4.1 Electrostatic Precipitator:-
Flue gas are sucked by the Forced Draft Fan and supplied to ESP
.Fly ash or dust is collection is
done in the Electrostatic Precipitator by imparting the negative
charge to the dust particles &
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attracting them towards positive plate disposal of the collected
dust is done by rapping the
electrode.
The ash or dust which is collected in ESP is coming to
hydrovecter then this ash is transfer red
along with water which is coming from NH3-2 plant to the ash
slurry pit. Then ash slurry is
disposed to ash pond area.
2.4.2 Stack:-
The flue gas after removal of dust id thrown to the outside the
chimney to atmosphere by the use
of induced draft fan .the height of the chimney is 80m &flue
gas from the other source of the
plant is also disposed to same chimney the flue gas which is
disposed to atmosphere with
following composition (SO2=500-600mg/Nm3, suspended
particles=110mg/Nm3)
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MECHANICAL WORKSHOP
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Mechanical workshop at NFL unit mainly committed to the
maintenance and repair work.
Various maintenance jobs are done here as per the job orders
given by different plants of NFL
unit. The mechanical department has futher different workshops
namely-:
Machine shop
Fabrication shop
Fitting shop
Earthmoving shop
Refrigeration shop
Details of the different workshops is given as following.
Machine shop
Fitting shop
Fabrication shop
Earthmoving shop
Refrigeration shop
MACHINE SHOP
Machining of a material involves repeated removal of material
from the job to give away the
required shape and size.
Machine shop has various machines that are being used for the
machining processes of the jobs
from the plant. Some of the machines in the shops are
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SLOTTER MACHINE
LATHE MACHINE
GRINDER MACHINE
BORING MACHINE
DRILLING MACHINE
MILLING MACHINE
PLANNER MACHINE
SHAPER MACHINE
SHEARING MACHINE
SHEET CUTTING MACHINE
LATHE MACHINE
Lathe is a power driven, genral purpose machine used for
producing mostly
cylindrical jobs or work pieces. As the piece of metal to be
machined is rotated on the lathe, a
single point cutting tool is advanced racially in to the
work
piece,removing the metal marterial in forms of chips.Main
difference between
lathes where as in the the other machines cutting tools is moved
an the work
piece remains stationary.
Parts of Lathe Machine
HISTORY OF LATHE
Most versatile machine tool in the machine shop
Oldest ancestor is the potters wheel(4000B.C)
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Next came pole lathe
This was developed into current lathe which are able to make
threads
Father of modern lathe HENRY MAUD SLAYS
Types of lathe machines found in the NFL mechanical
workshop-
Central lathe
Turret lathe
Capstan lathe
Centre lathe or engine lathe
It is most important and widely used machine in the lathe
family.its name is derived from the fact
that the earliermachine tools were driven by separate engines or
from the central engine with
over head belt and shafts .The stepped cone pulley or gear head
are often used for varying the
speed of the lathe machine
Turret lathe
It is a production machine used to perform a lot of task or
operation on a single job with
minimum wastage of time.Indexable square tool is Provided on the
cross slide or the mounting
turning and parting of tool. The Turret usually accommodates
tools for different operations like
drilling ,counter sinking etc
Capstan lathe
These are similar to turret lathe and incorporate capstan slide
which moves on a clamped in any
position.It is the best suited for the large scale production of
small parts because of its light
weight and short stroke of capstan slide
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SLOTTER MACHINE
Slotter machine is also called as vertical shaper machine .the
difference being that the ram is in
vertical direction instead of horizontal position.Also the table
or bed is mounted on a heavy base
and provided with mechanism that make possible forward backward
and side to side movement
. it also has adjusted head mechanism .
Advantages of vertical shaper or slotter machine :-
1. Setting of the job is more convenient because it is easier to
see, align, measure, clamp
2. Press generated by the cutting stroke is better supported by
the table bed
3. Circular and hollow jobs can be worked upon
4. Ram of vertical shaper can be adjusted up to 10 degrees.
Main functions of slotting machine :-
Internal key ways
Tapered key ways
Slots
Centric slots
Internal gear
SHAPER MACHINE
Shaping machine is generally called as shaper. Shaper is being
used for both
production and tool room work. The shaper can machine a flat
surface on a
horizontal , vertical , angular plane. On this tyoe of machine
,many types of work pieces can be
machined depending upon the tools used and the manner of
adjusting the various parts of the machine . Size of the shaper
is determined by
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the largest sized cube that can be machined on it. Working
principal is quick
return mechanism and forward stroke is cutting stroke and
backward is idle
stroke.
Difference in shaper and lathe machine :-
In shaper straight cutting is done where as in lathe circular
cutting is done In shaping machine
the tool moves in reciprocator fashion whereas in the lathe
machine the tool remains stationary
and the work piece moves.
Parts of Shaping Machine are :-
BASE : it is the reservoir for supply of oil circulated to the
moving parts of machine
ARPON: it supports the table
RAM: It is the main moving part of the shaper machine. It holds
and
drives the cutting tool back and forth across the work .
This is attached to rocker arm which is given an oscillating
motion by
turning of a large driving gear .this also has an adjustable pin
attached to
driving gear which acts as a crank which determines the length
of the ram
TOOL HEAD: it holds the cutting tool. it is attached to the
front of the
ram. Tool post is fastened to the clapper box
Main functions of the shaping machine :
Making slots
Tapered slots
external key on shaft
Hexagonal nut heads
Square nut head
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MILLING MACHINE
Milling machine is one of the most versatile and widely used
machine tool for
tool room and production purposes.
Milling is the process of removal of the material with the help
rotating multiple cutting tools
called as milling cutter. In general the work piece is fed into
the rotating milling cutter
Parts of the milling machine :-
Column
Knee
Saddle
Table
Spindle
Over arm
COULMN: It includes the base which I the main casting which
supports the other parts of
machine . The front of the column, the column face is machined
to provide an accurate guide for
the vertical travel of the knee
KNEE: It supports the saddle .feed change gearing is enclosed
within the
knee.knee can be raised or lowered on the column face.it is
supported and can
be adjusted with a elevating screw.
SADDLE: It supports the table . It is supported by the surfaces
of the knee
TABLE: It holds the workpiece. It has T-slots and is used to
hold the
jods .bolts fit loosely in the T-slots and are used to clamp the
vice.
SPINDLE: it holds and diverts various cutting tools.it has the
shaft mounted
on the bearing supported by the column.
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OVER ARM: it is mounted on the top of the column. It is guided
by the
machined dovetail surfaces
GRINDING MACHINE
Grinding is the process of finishing surface by means of
revolving abrasive wheel
In order to finish the job piece efficiently one must not only
be able to operate
The grinder but also understand abrasive and grinding wheels
,their shapes and
sizes for different type of work
ABRASIVE: An abrasive is any material that can wear material
softer than
itself .sand and sandstone are perhaps the oldest abrasives
known to mankind.
Abrasives can be natural or manmade.
Natural Abrasives: Emergy and corundum are two commonly used in
the
Industry to sharpen tool edge They occur as a miner deposit in
the earth crust .Aluminum oxide
is the best suited for grinding material that has high tensile
strength such as high spee steel and
high carbon steel.
Man made Abrasives: these are better than natural ones because
in these
purity and grain size can be controlled.
GRINDING WHEELS: Grinding wheel are formed by using a suitable
material to cement, bond,
abrasives grains together in the desired shape and size.
Hardness of the wheel is dependent upon
the amount and kind of binding
material being used. Hardness of wheel is always understood by
means of
strength of bond.
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TYPES OF GRINDING MACHINES
Surface Grinder
Cylindrical Grinder
Internal Grinder
Thread Grinder
SURFACE GRINDER: Surface grinding is the process of producing a
finished flat surfaces by
means of grinding machine employing revolving abrasive wheel.
Surface grinder machine
consist of spindle mounting a grinding wheel and table or
magnetic chuck for holding the work
piece
Uses of Abrasive Grinding : -
Sharpening cutting
Snagging
Finishing
PLANNER MACHINE
Planer is one of the basic machine tools used in machine shop.
Main function is
to produce flat surface on piece of work. The main difference
between planer
and shaper is that in planer machine the work piece moves In
reciprocating
motion while tool is fixed where as in the shaper machine it is
other way
round. It can be distinguished in two either Hydraulic or
Mechanical.
Main parts of Planer Machine are:
Bed
Table
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Saddle
Tool head
FABRICATION The process of joining metals or non-metal to from
an object which has specific
shape .This process is known as fabrication. Different types of
machines and welding are used in
the fabrication process or to fabricate an object.
THE WORKDONE AT THE SHOP ARE CLASSIFIED AS :
1) Metal cutting method :-
Oxy fuel gas cutting
Plasma cutting
2) Metal joining method :-
Oxy-acetylene welding
Arc welding
Tungsten inert gas welding
Oxy-acetylene Gas welding:
This process is particularly suitable for joining metal sheet
and plates and having thickness 2
to 50mm.
The filler metal is the addition metal, which is added to weld
in the form of welding rod.
The composition of the filler rod is usually the same or nearly
the same as that of the part
being welded.
To remove the impurities and oxides present on the metal to be
joined and to obtain stationary
bond flux is always implied during the welding expect sheet.
Various gas combustions can be used for producing a hot flame
for welding metals. Common
mixture of gases oxygen and other fuel gases.
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The oxy-acetyl welding mixture is used to a much greater extent
than other in the welding
industry.
The temperature of this welding flame in its hottest region is
about 3200 C.
CaC2 + 2H2O C2H2 + Ca(OH)2
ARC WELDING METHODS
Metal arc welding: In the arc welding metal rod is used as an
electrode,
while the work being welded is used as another electrode. The
temperature
produced is about 2400C and 2600C on the ve and +ve
electrode
respectively. During the welding operations, this metal
electrode is melted
by the heat of the arc and is fused with the base metal, thus
forming a
solid union after the metal has been cooled. Both AC and DC can
be
used .Adjusting the machine to correct amperage, which is
determined by
then size of the rode to be used ,start the welding operations.
The correct
welding speed is important.
SPECIFICATION OF ELECTRODES:
Where
1. E is used for covered electrode that is for coated
electrode.
2. Next two XX multiplies with 1000spin shows the tensile
strength.
3. Next X shows the position of joint to be welded in current
condition i.e. it may horizontal,
vertical or inclined
4. Last X shows the types of coating.