FABRICATION OF ABRASIVE JET MACHINE

Submitted in the partial fulfillment of the requirement for the award of

“DIPLOMA IN MECHANICAL ENGINEERING”

SUBMITTED BY:

1. B. ARUL KUMAR 4. J. VIJAY KUMAR 2. S. ARJA 5. T. EDISON 3. B. RAJESH KUMAR 6. K. VISHNU

Under guidance of

Mr. C. SARAVANAN, B.E.,

MARCH 2012.

DEPARTMENT OF MECHANICAL ENGINEERING.

VEL TECH POLYTECHNIC COLLEGEALAMATHI ROAD , AVADI-CHENNAI-600072

VEL TECH POLYTECHNIC COLLEGE

ALAMATHI ROAD,AVADI-CHENNAI-72

BONAFIDE CERTIFICATE

This is to certify that this Project work on

“AUTOMATIC CASTING CLEANING PROCESS”

submitted by …………………… ……………. Reg. No. ……………

in partial fulfillment for the award of

DIPLOMA IN MECHANICAL ENGINEERING

This is the bonafide record of work carried out by him under our supervision during

the year 2012

Submitted for the Viva-voce exam held on ……………..

H.O.D PROJECT GUIDE

INTERNAL EXAMINER EXTERNAL EXAMINER

ACKNOWLEDGEMENT

ACKNOWLEDGEMENT

At the outset, we would like to emphasize our sincere thanks to the Principal

Mr. PARTHASARATHY, M.E., encouragement and valuable advice.

we thank our Esquired Head of Department Mr V. BOOBALAN, B.E., for

presenting his felicitations on us.

We are grateful on our Entourages Mr.C. SARAVANAN, B.E., for guiding

in various aspects of the project making it a grand success.

We also owe our sincere thanks to all staff members of the Mechanical

Enginering Department.

Ultimately, we extend our thanks to all who had rendered their co-operation

for the success of the project.

CONTENTS

CONTENTS

Chapter No. TITLE

1. SYNOPSIS

2. THEORY OF ABRASIVE JET

MACHINE

3. PRINCIPLE OF OPERATION

4. BASIC MECHANISM OF SAND

BLASTING MACHINE

5. APPLICATION

6. ADVANTAGES AND DISADVANTAGES

7. DESCRIPTION OF PARTS IN THE SETUP

8. COST ESTIMATION

9. CONCLUSION

10. BIBILOGRAPHY

INTRODUCTION

INTRODUCTION

This is a self – assessment test on the part of the students to assess his

competency in creativity.

During the course of study, the student is put on a sound theoretical

foundation of various mechanical engineering subjects and of course, to a

satisfactory extent. Opportunities are made available to him to work on different

kinds of machines, so that he is exposed to various kinds of manufacturing process.

As a students learn more and more his hold on production technology

becomes stronger. He attains a stage of perfection, when he himself is able to

design and fabricate a device.

This is the project work. That is the testimony for the strenuous training,

which the student had in the institute. This assures that he is no more a student, he

is an engineer.

This report discuses the necessity of the project and various aspects of

planning , design, selection of materials, fabrication, erection, estimation and testing.

SYNOPSIS

SYNOPSIS

This project presents the working of sand blasting ABRASIVE JET machine

based on (abrasive jet machining) technique. The material removal rate is based on

the force and strength of abrasive need.

Abrasive jet machine can very well be used for removal of burs, paint, grease

and oil from any material. This is widely used in surface finishing area.

Flow rate of air and abrasive can control to get the desired proportion of the jet.

THEORY OF ABRASIVE

JET MACHINE

THEORY OF ABRASIVE JET MACHINE

ABRASIVE JET machine system consists of the following four major sub system,

1. Gas propulsion system

2. Metering system

3. Delivery systems

4. Abrasive collection

The gas propulsion system provides the steady supply of clean, dry gas used to

propel the abrasive particles. Depending upon the demands of the installations,

either air compressor or bottled gas may be used. If an air compressor proper lines

fitness must be used to avoid water or oil contamination of the abrasive powders.

Most uses decide on bottled gas systems since the gas guaranteed to be dry and

clean (oxygen should never be used as it presents fire hazards)

The metering system must inject a uniform adjustable flow of abrasive

particle into the gas stream. Generally this accomplished by powder hopper that

feeds into a vibrating chamber which in turn causes the powder to be metered

uniformly into a jet stream. The powder flow rate is directly adjustable by varying

the amplitude of the vibration.

The dust collection system is incorporated into sand blasting machines

systems which found necessary to maintain to operators exposure to dust with in

permissible limits.

Nozzles:

The sand blasting machine nozzles are typically made to either tungsten

carbide or sapphire. Tungsten carbide nozzles with either round or rectangular holes

are available an it lasts for an average of 30 hours. Sapphire nozzles available only

in round configurations last an average of 300 hour but are three to eight times more

expensive. Round nozzles are available with diameters ranging from 0.12 to 0.15

mm with 0.5mm being the most common. Rectangular nozzles ranges from 0.07

inch to 0.17 inch.

The life of nozzle must be partly defined by its application. Exacting operating such

as cutting requires that nozzles be changed more often than when etching cleaning.

A nozzle wear, the jet stream tends to diffuse faster, resulting in material damage

outside that intended line of cut. This known as stray cutting or over spray.

Rectanglular nozzles create over spray compared with round types.

Abrasives:

The various abrasives used in sand blasting machine are selected by

application. Aluminimu oxide, one of the most commonly used materials, is used to

clean cut and debars. Silicon carbide, a harder abrasive is effective for the same

applications as aluminium oxide but is usually applied only when the work piece

material is very hard.

Polishing surfaces toa mate finish or penning surface is accomplished with

glass bead. Crusted glass provides sharper edges than glass bends and can therefore

be used for heavier cleaning; and penning operations.

The lightest applications, such as the cleaning cutting and debarring of soft

materials are performed with sodium ;bi carbonate (baking soda) which is a soft

powder and can leave surface free of scratches. It is important to note that sodium

bicarbonate is hygroscopic and will absorb moisture if heated above 49deg.C thus

rendering it useless if allowed to become moist and therefore moist be kept

completely dry at all times.

Because abrasive particles size is important abrasives are available in many

sizes ranging from 10 to 50 microns. The smaller sizes are most useful for polishing

and cleaning, while the larger sizes are best for cutting and penning.

PRINCIPLE OF OPERATION

ABRASIVE JET OPERATION

Three methods are used to remove the sand from the surface of large

castings. In the sand-blasting machine, the sand particles are thrown with

very high velocity against the casting surface by compressed air. The

impacts of the high force sand on the surface of the castings remove the

sand and clean the surface.

BASIC MECHANISM OF ABRASIVE JET

MACHINE

BASIC MECHANISM OF ABRASIVE JET

The basic mechanism involved in machining material with abrasive jet has

been related to the impacting velocity of the particle and fracture mechanics. A

method has been proposed to estimate the velocity of the abrasive. Particles as and

material removal rate. Numerical results have been computed for a given input data

and compare with experimental surface.

MECHANISM OF

MATERIAL REMOVAL

MECHANISM OF MATERIAL REMOVAL

Material removals in abrasive are used in sand blasting machining course due

to erosion caused by the impact of high velocity stream of abrasive particles on to

the work piece. Although a brittle material does not show plastic deformation, but

indentation fracture studies have revealed that plastic deformation does occur even

in very brittle material like ceramics glasses when indenter diameter a critical valve

‘d’ pc.

Indentation studies have shown that different sets of crack system are formed

during leading as well as un leading past of the indentation cycle. The sequence of

events during indentation with a sharp indenter for one complete indentation cycle is

shown schematically.

During the leading cycle, increase in the load the indenter causes, elastic

plastic deformation followed by the formation of medium crack system. At the start

of the unloading cycle the walls of the medium crack move closer but fracture

debris. Indeed, the residual stress may actually drive any partially formed medium

crack to full development. Just prior to complete unloading the residual stress

become sufficient to initiate and propagate a completely new system of side ways

spreading saucer lateral cracks. Theses lateral cracks continue their speed when the

indentation load is finally removed and actually interest the free surface to produce

microchips and results in material removal from the work piece.

Material removal rate:

Under impact situation plastic deformation in brittle materials occurs only

when small spherical particle impinging into the target, surface above a certain

velocity, thus there exits a velocity there should to cause plastic deformation

resulting in the formation of lateral cracks. As soon as the spherical particle touches

the surface of a body contact stress are setup.

Extending hertz analysis for impact situation and relating the maximum shear

stress developed below the contact. Zone to the Vickers’s hardness (Ht)of the target

material like glass, the there haul velocity (vpe) to cause plastic deformation can be

expressed fracture morphological studies have revealed that the lateral cracks are

produced at the elastic plastic boundary inside the target. This is based on the

assumption that during the elastic plastic bound inside the target. This based on the

assumption that during the collision the impacting parties deform only elastically

and plastically. Further, the target material may be assumed to under go plastic

deformation of the target and the elastic deformation of impinging particle during

collusion cycle, the depth at which the lateral cracks if formed can be obtained in

terms of the impact velocity and physical parameters of the impinging particle and

the target material.

The micro size chips which are formed due to the interaction of lateral cracks

from adjacent impact may assumed to be a cylindrical in ;shape having depth equal

to lateral depth and radius equal to lateral crack. Using thinks approach the volume

of material removed per impact (V) can be expected.

Material removal in abrasive are used in sand blasting machine occurs due to

erosion caused by multiple impacts. Assuming that all particles in the jet during

impact have velocity equal to that at center of nozzle, the cumulative effect of

multiples particle impact can be obtained by direct multiplication of the number of

effective impacts with the volume removed by a single impact. The theoretical

number of impact per unit time can be estimated from the umber of particle passing

per unit time at any section of the air abrasive mixture nozzle. Thus the theoretical

umber per unit time.

On the mass flow rate abrasive particles in the nozzle material density and

size of the particle. In real situation the effective number of impact on the work

piece surface per unit time is likely to be less than the theoretical number of impacts

because of the particle from the work piece surface with the income particle of the

jet. The particle interaction effect primarily depend son the SOD distant. At small

SOD due to less flaring and high particle concentrating on the nozzle the particle –

particle interaction effect will be more causing a reduction in the number of

effective impacts. Thus the effective number of impacts will be negligibly small a

nearby zero SOD. When the SOD distance is higher the particle – particle

interaction effect is low and the number of effective impacts.

Approach the theoretical valve. Further, the particle – particle interaction

effect will be more at high mixture rate owing to the presence of a large number of

particle per unit volume of mixture. For the sake of simplicity however, the effect of

mixture ratio on particle – particle interacting is usually ignored

APPLICATION

.

APPLICATION

These methods are used to remove the sand from the surfaces the large casting

In the ABRASIVE JET machine, the sand particles are thrown with

very high velocity against the casting surface by compressed air

The impact of the high force sand on the surface of the castings remove the

sand and clean the surfaces

This mechanism is also used for water servicing.

ADVANTAGES AND

DISADVANTAGES

ADVANTAGES AND DISADVANTAGES

ADVANTAGES

It is simple in processes

Fine amount of material is cleared

It requires less skill labor

Cheaper method

Very low capital cost

High accuracy of material removal

DISADVANTAGES

More space is required storage for sand

Rained ay or winder day sand forms as mud

Time consumption process

DESCRIPTION OF THE

PARTS IN THE SETUP

DESCRIPTION OF THE PARTS IN THE SETUP

Air compressor:

A machine providing gas at high pressure is called air compressor and work

must be done on it.

Name Plate details

Motors - 3 HP

RPM - 1440

AMPS - 4.5

Tested Pressure - 10 kg/sq.cm

It takes atmosphere air in, compresses it and delivers the high-pressure air to

the storage vessels from which it is taken for the process usages. The compressor is

driven by the prime mover.

It is a device, which is used to control the flow of air, which is to be admitted

into the champers in the later stage.

This is done by a valve, which can be operated by a knob. This is made of brass.

Hopper:

It is one of the part which is used to feed the abrasive particles to the mixing

chamber and is also used for storing the particle. This is made in to a circular cross

section cylinder of a length 350mm and a diameter of 210 mm.

At the bottom of section a conical shape is brazed easier feedings. The

material used in C.L sheet of gauge 22 capacities is 15 kgs.

Mixing chamber:

Mixing chamber is a part or device which is employed for mixing the abrasive

particle\les or sand with that of air in a proper proportions in order to use in such

way that the nozzle hole doesn’t get struck by the mixture.

This is made as a shape of the circuit cross section throughout length. It’s

length is 300mm and has diameter of 210mm. It has three openings one in the

circumferential space and two other openings on in top and the other in bottom of

champers.

Position - Vertically located

Specification - diameter - 210mm

Height - 300 mm

Material:

The material used for the constructing of this project C.I. Sheet of 22 gauges.

This material used for piping to connect holes is of C.I. and are connected to the

holes by brazing

Nozzle:

A nozzle is a tapering mouth piece, which is fitted to lthe outlet of a pipe and

is generally used to have a high velocity of fluid acid converts pressure head into

kinetic head at its outlet.

Specification:

Nozzle outer dia - 10.mm

Nozzle Inner dia - 4.0 mm

Angle of taper - 20

Length of nozzle - 75mm

Material:

The type of material used for the nozzle is copper and a M.S. the schematic

representation is show in figure.

COST ESTIMATION

COST ESTIMATION

S.NO ITEM MATERIAL QUANTITY

AMOUNT

1 GATG VALVE BRASS 2 NOS 800.002 HOSE NIPPLE BRASS 3 NOS 200.003 HOSE NIPPLE BRASS 1 NOS 100.004 REDUCER GI 2 50.005 MIXING CHAMPER GI 1 1000.007 T JOINT GI 1 100.008 HOSE RUBBER 2 200.009 HOSE CLIP CI 4 20.0010 NOZZLE CI 2 200.00

11 MS ANGLE MS 1 900.0013 PIPE GI 1 200.0014 PIPE CLAMP GI 7 50.0016 LABOR COST 900.0017 MISE COST 300.00

TOTAL COST 5000.00

CONCLUSION

CONCLUSION

We have successfully completed the project work “FABRICATION OF

ABRASIVE JET MACHINE” at our institute.

In executing this project work, we were exposed to many practical problems

and difficulties, Facing such situation and solving the problems has given us a

confidence and courage, which are very essential for a successful engineer.

By doing this project work, we understood the working principle and uses of

various sensors, switches, relays and motors. As more and more industries are

automating their manufacturing process, it will be of no doubt that micro controller

will be an integral part of any process in industry in the near future and we have

utilized the micro controller for the completion of this project.

Once again we express our sincere thanks to our staff members.

BIBILOGRAPHY

BIBILOGRAPHY

1. PRODUCTION TECHNOLOGY - HAJARA CHOWDRY

2. FOUNDRY TECHNOLOGY - O.P. KHANNA

3. PRODUCTION ENGINEERING - P.C. SHARMA

4. WORKSHOP TECHNOLOGY - BAWA

5. PRODUCTION TECHNOLOGY - SS MANAIAN

PHOTO VIEW

PHOTO VIEW