report production b.pdf

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CHAPTER ONE WELDING

Welding is the process of permanently jointing two or more pieces of

material, often metallic, together by the application of heat, pressure,

Or both

1.1 Shielded Metal Arc Welding (SMAW)

The heat generated melts a portion of the tip of the electrode, its

coating and the base metal in the immediate area of the arc. A weld

forms after the molten metal a mixture of base metal (work piece),

electrode metal, and substance from the coating on the electrode

which solidifies in the weld area

Fig. 1.1

SMAW

1.2 Submerged Arc Welding (SMAW)

The flux is fed into the weld zone by gravity flow through a nozzle.

The thick layer of flux completely covers the molten metal and

protects the metal from spat

process. The flux also acts as thermal insulator, allowing deep

penetration of heat into the work piece.

The consumable electrode is coil of bare round wire and is fed

automatically through a tube (welding gun)

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Submerged Arc Welding (SMAW)



protects the metal from spatter, sparks and fumes of the SMAW


penetration of heat into the work piece.

electrode is coil of bare round wire and is fed

automatically through a tube (welding gun)

Fig. 1.2

SMAW



ter, sparks and fumes of the SMAW


electrode is coil of bare round wire and is fed

1.3 Gas Metal Arc Welding (GMAW)

In gas metal arc welding (GMAW) the weld area is shielded by an

external source of inert gas, such as argon, helium, carbon dioxide

or various other gas mixtures.

The consumable bare wire is fed automatically throu

the weld arc. In addition to the use of inert shielding

are usually present in the electrode metal itself to prevent oxidation

of the molten weld puddle

3

Gas Metal Arc Welding (GMAW)


external source of inert gas, such as argon, helium, carbon dioxide

or various other gas mixtures.

The consumable bare wire is fed automatically through a nozzle into

the weld arc. In addition to the use of inert shielding gas, d


of the molten weld puddle

Fig. 1.3

GMAW


external source of inert gas, such as argon, helium, carbon dioxide,

gh a nozzle into

gas, deoxidizers


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1.4 Defects Of Welded Joints

1. Porosity

Caused by trapped gases released during solidification of the weld

area by chemical reactions during welding or contaminants

2. Incomplete fusion

Poor weld beads

3. Incomplete penetration

Occurs when the depth of the welded joint is insufficient

4. Slag inclusion

Are compounds such as oxides, fluxes, and electrode coating

materials that are trapped in the weld zone

1.5 Welding inspection

1. Ultrasonic

Ultrasonic

nondestructive testing is

well established as a

method of insuring the

integrity of structural

welds in steel, titanium,

and aluminum, being

able to identify cracking,

porosity, incomplete

penetration, inclusions,

and lack of sidewall

fusion, and similar Fig. 1.4

defects that can compromise ultrasonic inspection

weld strength

2. Dye penetrant inspection

Nondestructive testing

low surface tension is poured on to

the surface of the welded joint it

seeps into the crack or cavity.

Wiping the surface of the p

metal and weld leaves liquid in the

crack

3. Visual inspection

The experienced inspector will examine the joint visually,

dimension or weld depth by universal weld gauge and fillet angle

by simple fillet weld gauge

Fig. 1.5

Simple fillet weld gauge

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Dye penetrant inspection

Nondestructive testing if liquid has

low surface tension is poured on to

ce of the welded joint it

seeps into the crack or cavity.

Wiping the surface of the parent

metal and weld leaves liquid in the

Fig. 1.4


experienced inspector will examine the joint visually,


by simple fillet weld gauge

Fig. 1.5 Fig. 1.6

Simple fillet weld gauge Universal weld gauge


experienced inspector will examine the joint visually,


Fig. 1.6

Universal weld gauge

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CHAPTER TWO FLUID POWER

Fluid power is technology that deals with the generation, control and

transmission of power using pressurized fluids. It can be said that fluid

power is the muscle that moves industry. This is because fluid power is

used to push, pull, regulate or drive virtually all the machines of

modern industry

2.1 Hydraulic pumps

A pump which is the heart of the hydraulic system converts

mechanical energy into hydraulic energy. The mechanical energy is

delivers to the pump via prime mover such as an electric motor. Due

to mechanical action, the pump creates a partial vacuum at its inlet.

This permits atmospheric pressure to force the fluid through the inlet

line and into the pump. The pump then pushes the fluid into the

hydraulic system

2.1.1 Gear pump

a. External gear pump

Develops flow by crying fluid between the

teeth of two meshing gears. One of the gears

connected to drive shaft connected to prime

mover. The second gear is driven as it

meshes with the driver gear

Fig. 2.1

External gear pump

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b. Internal gear pump

This pump consists of an internal

gear or pinion, a regular spur gear

or ring gear and crescent shaped

seal. As power is applied to an

internal gear the motion of the

gear draws the fluid from reservoir

and forces it around both sides of

the crescent seal which acts seal

between the suction and discharge Fig. 2.2

ports when the teeth mesh on the Internal gear pump

side opposite to the crescent seal, the fluid forced to enter the

discharged port

2.1.2 Piston pumps

A piston pump works on the principle that a reciprocating piston

can draw in fluid when it retracts in the cylinder bore and

discharge it when it extends

a. Axial piston pump

That contains a cylinder

block rotating with the drive

shaft. However, the

centerline of the cylinder

block is set at an offset angle

relative to the center line of

the drive shaft

Fig. 2.2 axial piston pump

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b. Radial piston pump

This design consists of a pintle to

direct fluid in and out of a

cylinder. A cylinder barrel with

pistons and rotor containing

reaction ring for pumping action

the reaction ring is Fig. 2.3

moved eccentrically with respect Radial piston pump

to pintle or shaft axis. As the cylinder barrel rotates the piston

on the one sides travel outward

2.2 Directional Control Valve

Direction control valve are used to control the direction of flow in

hydraulic circuit. Any valve (regardless of its design) contains ports

that are external openings through which fluid can enter and leave

via connecting pipe lines

1. Check valve

Is two ways that used to

permit free flow in one

direction and prevent any flow

in the opposite direction.

Fig. 2.3

Check valve

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2. Three ways or four valves

Three ways valves contain

three ports and four ways

contain four ports they are

typically of the spool design. A

spool is a circular shaft

containing lands that are large

diameter sections machined

to slide in a very close fitting

bore of the valve body. The

spool can be actuated by

compressed fluid or gas or

pneumatic, mechanically (cam

and spring), manually and solenoid Fig. 2.4

Four ways valve

2.3 Hydraulic cylinder

Pumps perform the function of

adding energy to the hydraulic

system for transmission to some

output location. Hydraulic cylinder

does just the opposite as a linear

motion. They extract energy from

the fluid and convert it to

mechanical energy to perform

useful work

Fig. 2.5 Hydraulic cylinder

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2.4 Hydraulic motors

A limited rotation hydraulic motor provides rotary output

motion over a finite angle. This device produces high

instantaneous torque in either direction and requires only a

small space and simple mounting

Hydraulic motors can rotate continuously and as such have the

basic configuration as pumps. However, instead of pushing n

the fluid as pumps do, motors are pushed on by the fluid

In the way hydraulic motors develop torque and produce

continuous rotary motion

Hydraulic motors types

a. Gear motor

b. Piston motors

CHAPTER THRE DIESEL ENGINE

A diesel engine (also known as a compression

internal combustion engine

initiate ignition to burn the

chamber. This is in contrast to spark

engine (gasoline engine) or

to gasoline), which uses a

3.1 How diesel engines work

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CHAPTER THRE DIESEL ENGINE

A diesel engine (also known as a compression-ignition engine) is an

internal combustion engine that uses the heat of compression

to burn the fuel, which is injected into the combustion

. This is in contrast to spark-ignition engines such as a

(gasoline engine) or gas engine (using a gaseous fuel as opposed

), which uses a spark plug to ignite an air-fuel mixture

How diesel engines work

Fig. 3.1

Diesel Cycle PV

ignition engine) is an

heat of compression to

combustion

ignition engines such as a petrol

(using a gaseous fuel as opposed

fuel mixture

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The diesel internal combustion engine differs from the gasoline

powered Otto cycle by using highly compressed hot air to ignite the

fuel rather than using a spark plug (compression ignition rather than

spark ignition).

In the true diesel engine, only air is initially introduced into the

combustion chamber. The air is then compressed with a

compression ratio typically between 15:1 and 22:1 resulting in 40-

bar (4.0 MPa; 580 psi) pressure compared to 8 to 14 bars (0.80 to

1.4 MPa) (about 200 psi) in the petrol engine. This high

compression heats the air to 550 °C (1,022 °F). At about the top of

the compression stroke, fuel is injected directly into the compressed

air in the combustion chamber. The fuel injector ensures that the

fuel is broken down into small droplets, and that the fuel is

distributed evenly. The heat of the compressed air vaporizes fuel

from the surface of the droplets. The vapor is then ignited by the

heat from the compressed air in the combustion chamber, the

droplets continue to vaporize from their surfaces and burn, getting

smaller, until all the fuel in the droplets has been burnt. The start of

vaporization causes a delay period during ignition and the

characteristic diesel knocking sound as the vapor reaches ignition

temperature and causes an abrupt increase in pressure above the

piston. The rapid expansion of combustion gases then drives the

piston downward, supplying power to the crankshaft.

Fig. 3.2 Diesel engine process

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3.2 Engine parts

Fig. 3.3

Engine parts

1. Piston cylinder

A cylinder is the central working part of a reciprocating

engine or pump, the space in which a piston travels.

Multiple cylinders are commonly arranged side by side in a

bank, or engine block, which is typically cast from aluminum

or cast iron before receiving precision machine work. The

reciprocating motion of the pistons is translated into

crankshaft rotation via connecting rods.

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Fig. 3.4

Piston

2. Crank shaft

It is the part of an engine that translates reciprocating linear

piston motion into rotation. To convert the reciprocating

motion into rotation, the crankshaft has "crank throws" or

"crankpins", additional bearing surfaces whose axis is offset

from that of the crank, to which the "big ends" of the

connecting rods from each cylinder attach

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Fig. 3.4

Crank shaft

3. Fuel injector

The injector on a diesel engine is its most complex

component and has been

the subject of a great deal

of experimentation. In any

particular engine, it may be

located in a variety of

places. The injector has to

be able to withstand the

temperature and pressure

inside the cylinder and still

deliver the fuel in a fine

mist. Getting the mist

circulated in the cylinder so

that it is evenly distributed Fig 3.5 Fuel injector

is also a problem, so some diesel engines employ special

induction valves, pre-combustion chambers or other devices

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to swirl the air in the combustion chamber or otherwise

improve the ignition and combustion process.

4. Turbo charger

Turbochargers are a type of forced induction system. They

compress the air flowing into the engine. The advantage of

compressing the air is that it lets the engine squeeze more

air into a cylinder, and more air means that more fuel can be

added. Therefore, you get more power from each explosion

in each cylinder. A turbocharged engine produces more

power overall than the same engine without the charging.

This can significantly improve the power-to-weight ratio for

the engine

Fig. 3.6 Turbocharger

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CHAPTER FOUR INDUSTRIAL SAFETY

4.1 Industrial safety

Is recognizing and evaluating the problem size and eliminate control or

reduce the danger from the bad effect of this danger and also to

training and educate the workers on this type of industrial safety

equipment.

Normal physical conditions:

The worker must work in the original life condition to make safe on his

healthy.

The normal physical conditions are: -

1- temperature at 37-37.8C 2- relative humidity 45% 3- Air at 1 atmosphere 4- uncontaminated air and dust free 5- acceleration at 1g = 9.8 m/sec

2 6- day light 7- noise less than 80DB

The environmental conditions are:-

1- Too hot or too cold. 2- Noise. 3- Sufficient light. 4- Color. 5- Relative humidity. 6- Vibration of the machine.

7- Air particulate. 8- Gases of high harm. 9- Water and chemical vapors.

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4.2 Air Pollution:

Types of air pollutants:

1-Dust:

Is contain the smoke and fine dust and fibers, the different between

these types of dust is it volume and length.

2-Gases:

Is the gases produced by the act of the industrial operations and

manufacturing process.

3-Vapors:

Is a vapors produced from the vaporization of the water and benzene

and toluene and alcohol.

4-Smoke:

Is a small droplet of a diameter from (0.001 to 1)?

4.3 Fire Accidents:

The combustion is a very fast combination of two or more material with

high flammability in sufficient of a suitable catalyst.

Type of fire:

• complete combustion

• incomplete combustion

4.4 Accidents:

The accident is a sudden chock occurs to the work.

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Accident types:

• General accident far away from the work area.

• Industrial operations accidents.

• Disaster accidents (normal disaster).

The losses occur from the accidents:

1- Losses in the materials machine and work. 2- Stop the work to a certain time interval. 3- Worker injury.

4- Loss in the production of a well trained worker. 5- Healing the worker cost. 6- Give money for the dead and high injury workers.

4.5 Problems occurs in work area

There are much trouble may occur in the working such as:

• The human mistakes or the folly behavior.

• The ability of the worker to deal with the machine.

• Bad weather condition (noise, humidity).

• Worker inattention.

• Stairs bad construction.

• Stresses for any reason.

• Human sociology.

• The bad cleaning of the work area.

• Holes in the floor without attention.

• Bad organizing of the internal transport.

• Transmission of motion belt uncovered.

• Transportation mistakes(mechanical, etc)

• Bad use of hand tools.

• Foal of bodies on workers without saving.

• Toxic material escaping.

• Flame causes improvement.

• Walls foaled on the workers.

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• Atomic radiation.

• Sudden conditions.

• Bad system organization of the factory management.

• Workshop machine and the revolving body volatile.

• Explosion and fire accidents.

• Transportation’s accidents.

• Electrical mistakes.

• Brake down of building and machine.

• Surface condition unsuitable.

4.6 Engineer Rule:

The engineers have the digest rule in the accident happening or

accident protection. So we will now discus it now:

1- Building and machine maintenance. 2- Organizing and clean the work area. 3- Worker training on the industrial safety equipment’s. 4- Check on the worker health periodically. 5- Presents to the good worker or the best one on using the

industrial safety equipment. 6- Be sure on the safety of the hand tool.

7- Training and paste a instruction notes.

8- Applies the physical engineering giving to improve relaxation

the worker in his work.

9- Make protection on the danger machine especially in the

revolving machines.

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4-7 protection from Workshops Machine:

To make sure that the workshops machine is in safe usage for the

workers. The following Precautions Must Be Taken into

Consideration:

1- The machine must be stopped during maintenance. 2- No one deal with the machine except the training worker. 3- The industrial safety equipment must be taken in to

consideration. 4- Ensure of installing the tools on the machine. 5- Light availability.

6- Cleaning tools must be available and use on the chip cleaning. 7- Make a wall around the revolving parts of the machine.

4-8 Safety Instructions and Sings:

Safety signs in the company departments are hanged on all walls

and all labors and engineers follow their instructions.

Fig. 4.1 safety instructors

Documents

report production b.pdf