PRASAD V. POTLURI

SIDDHARTHA INSTITUTE OF TECHNOLOGY

KANURU, VIJAYAWADA – 520007.

DEPARTMENT OF MECHANICAL ENGINEERING

A MINI PROJECT REPORT ON SUGAR CANE

CRUSHING ROLLERS

PRESENTED BY : P. GIRIDHAR (09501A0335)

P. J. SANDEEP (09501A0342)

S. AKHIL (09501A0353)

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ACKNOWLEDGEMENT

We are deeply grateful to Dr. K. Shivaji Babu, Head of the department of Mechanical

Engineering, Prasad V. Potluri Siddhartha Institute of Technology, for permitting us to work in

Kristna Engineering Works.

We are also grateful to Sri. T. Raghava Prasad (Managing Partner), KEW, for permitting us to

do a mini- project at Kristna Engineering Works.

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MINI PROJECTON

SUGAR CANE CRUSHING ROLLERS

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CONTENTS

Chapter Page No

INTRODUCTION 05

MANUFACTURING PROCESS OF SHELL 07

PROCESS FOR SHAFT 11

TESTING OF ROLLER SHAFT 14

FITTING OF SHAFT IN THE SHELL 15

FINAL OPERATION OF SHELL 16

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Chapter 1

Introduction

After harvesting, cane is transported to the mill. So as to extract the juice from the sugar cane, pairs of rollers

feed the cane through a series of mills. Each mill consists of three large rollers arranged in a triangular

formation. This process separates the sugar juice from the fibrous material, called Bagasse. So here we learn

about the manufacturing process of cane crushing rollers. This cane crushing roller has the following parts

1) Forged shaft

2) Casted shell

Casted shell is mounted on the forged shaft. One end of the forged shaft is connected to the transmission drive

unit with pinion and is mounted on a fixed end bearing housing in such a manner, so that it can move freely. On

the side of drive unit bearings are placed. Cast iron juice rings are fixed on the sides of the shell so that the juice

may not enter into to the bearings or shaft while crushing the cane. As shown in fig 1.

1. Scope:Scope specifies the physical properties and technical requirements of the shell and shaft materials, method of construction, recommended tolerances and various tests for the cane crushing rollers.

2. Terminology:

The various terms relating to sugar mill rollers used in this standard are as follows.

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Fig. Sugar cane crushing roller: shell-shaft assembly

Shaft – A round forged and machined steel bar on which cast iron shell is fitted.

Shell Seat – The long straight portion of shaft on which the shell is fitted.

Roller Journal – The polished surface at both ends of shell-seat on which bearings are fitted.

Pintle End – The shaft end having a key-way for sprocket-fitting is known as pintle end.

Square End – The shaft end on which pinion and couplings are fitted.

Shell – A hollow cast-iron round which is shrunk-fitted on the shaft.

Flange Fixing Holes – These holes are drilled and tapped at both ends of the shell of the top roller to facilitate

fitting of steel flanges. The number and size of these holes vary according to different shell sizes and design.

Keeper and Guard Rings – These rings are made of mild steel and are shrunk fitted on both ends of the shell

to safe guard against shifting of shell towards either end during working and also to avoid entering the juice into

the shell. Holes are drilled and tapered on the keeper rings of bottom rollers to fit the juice rings which prevent

entering of juice in the bottom roller bearings. The height of juice rings should not be less than 50mm.

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Chapter 2

MANUFACTURING PROCESS OF SHELL

Shell:

The shell shall be made out of coarse-grain iron and the microscopic structure shall conform to type ‘A’

distribution of graphite flakes in grey cast iron, as given in IS: 7754-1975.

Fig. Raw Material: Pig Iron + Lime Stone

Fuel:

Coke is used, as it gives high temperature up to 1350 degrees centigrade so as to melt the metal.

Composition:

Fig. Composition of pig iron

Mechanical Properties:

To have less wear and tear of the surface, the surface hardness of the shell casting shall be maintained within

the range of 180-210 BHN, as tested by Polde hardness testing method.

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Shrinking:

The shell shall be shrunk fit on the shaft throughout its length and there shall be no counter bore in the shell. For

sound gripping, the shrinkage allowance shall range between 0.07 and 0.08mm per 100 mm shaft diameter.

PROCESS OF CASTING OF THE SHELL:

Cupola furnace:

It is furnace from which molten form of metal is produced. The furnace is filled with layers of coke and ignited

with torches. When the coke is ignited, air is introduced to the coke bed through ports in the sides

called tuyeres. When the coke is very hot, solid pieces of metal are charged into the furnace through an opening

in the top. The metal is alternated with additional layers of fresh coke. Limestone is added to act as a flux. As

the heat rises within the stack the metal is melted. It drips down through the coke bed to collect in a pool at the

bottom, just above the bottom doors. When the metal level is sufficiently high, the cupola attendees open the

"tap hole" to let the metal flow into a ladle or other container to hold the molten metal. When enough metal is

drawn off the "tap hole" is plugged with a refractory plug made of clay. Slag will rise to the top of the pool of

iron being formed. A slag hole, located higher up on the cylinder of the furnace, and usually to the rear or side

of the tap hole, is opened to let the slag flow out. The viscosity is low (with proper fluxing) and the red hot

molten slag will flow easily. Molten metal is transferred into the required mould by means of ladle.

Fig. Cupola Furnace

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Pattern:

From the design, provided by an engineer or designer, a skilled pattern maker builds a pattern of the object to

be produced, using ms plate metal. For make a shell a hollow metal cylinder is made in which sand casting is

done. So as to get the internal diameter for the shell a round pillar made of graphite mixed with some content of

cement is introduced in between the pattern so as to get the mould of shell.

Fig. Pattern

Sand Casting:

Sand casting, also known as sand molded casting, is a metal casting process characterized by using sand as

the mold material. It is relatively cheap and sufficiently refractory even for steel foundry use. A suitable

bonding agent (usually bentonite) is mixed or occurs with the sand. The mixture is moistened with water to

develop strength and plasticity of the clay and to make the aggregate suitable for molding. Sand castings are

produced in specialized Factories called Foundries. Sodium based bentonite is mostly used here. As it has 95%

silica content in it. And it can resist high temperatures.

Fig. Sand Casting

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Casting:

Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a

hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting,

which is ejected or broken out of the mold to complete the process. After the metal solidifies, metal pattern is

removed and shell is extracted. Then the shell is send to the work shop.

Extraction of shell:

Pattern is removed after the shell is cool, then the shell is taken out. Shell taken out from the casting after it is

solidified it would be like in the figure given below.

Internal Boring:

Shell is mounted on the boring machine and boring is performed in the internal diameter of the shell so as to get

the required diameter with the help of single point cutting tool. Internal size finishing and sizing done by the

machine is shown below.

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CHAPTER 3

PROCESS FOR SHAFT

Material:

The sugar- mill rollers shall consist of a forged steel shaft. So the shaft shall be made of forged, normalized

steel conforming to the grade C45 IS: 1570-1979 RA1998.

Chemical properties of shaft:

Mechanical properties of shaft:

Forged shaft specification:-IS15701979

A fillet radius of 8mm between the journal and the shaft shall be provided.

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Machining of the forged shaft consists of the following operations:-

1. Plane turning operation

2. Square milling

3. Keyway milling

4. Drilling

Milling:

Milling is an important process of manufacturing technology and basically it refers to the removal of metal

from the work piece using a tool which has several cutting points and is rotating about its axis. Thus each

cutting point removes a little bit of the metal but since there are multiple such points and the tool is rotating at a

fast speed, the overall removal is quite brisk. The main advantage of the milling machine is that it can be used

to perform literally any operation with a great degree of accuracy.

Square Milling:

The workpiece should be properly mounted, the cutter centrally located, and the workpiece raised until the

milling cutter teeth come in contact with the workpiece. At this point, the graduated dial on the vertical feed is

locked and the workpiece moved longitudinally to allow the cutter to clear the workpiece. The vertical hand

feed screw is then used to raise the workpiece until the cutter obtains the total depth of cut. After this

adjustment, the vertical adjustment control should be locked and the cut made by feeding the table

longitudinally. Tool will have so many cutters around it.

Fig. Square Milling Cutter Tool Fig. After the square milling operation

Keyway Milling:

The usual Mill consists basically of a motor driven spindle, which mounts and revolves the milling cutter, and a

reciprocating adjustable worktable, which mounts and feeds the workpiece. Keyways are grooves of different

shapes cut along the axis of the cylindrical surface of shafts, into which keys are fitted to provide a positive

method of locating and driving members on the shafts. A keyway is also machined in the mounted member to

receive the key. The type of key and corresponding keyway to be used depends upon the class of work for

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which it is intended. The most commonly used types of keys are the Woodruff key, the square-ends machine

key, and the round-end machine key.

Drilling:

A drill is a tool fitted with a cutting tool attachment or driving tool attachment, usually a drill bit or driver bit,

used for drilling holes in various materials or fastening various materials together with the use of fasteners. The

attachment is gripped by a chuck at one end of the drill and rotated while pressed against the target material.

The tip, and sometimes edges, of the cutting tool does the work of cutting into the target material. This may be

slicing off thin shavings (twist drills or auger bits), grinding off small particles (oil drilling), crushing and

removing pieces of the workpiece (SDS masonry drill), countersinking, counter-boring, or other operations.

Plain turning operation:

Plain turning is the operation of removing excess amount of material from the surface of a cylindrical job. Shaft

is mounted on the lathe. Turning operation is performed with the help of single point cutting tool as to decrease

the diameter of the shaft and so to get the required.

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Chapter 4

TESTING OF ROLLER SHAFT

The shaft shall be ultrasonically tested as given in IS: 8791-1978 ‘Code of practice for ultrasonic flaw detection

of ferritic steel forgings.’ To have a thorough examination of the entire surface of the shaft, surface /sub-surface

defects shall also be detected by dye penetration test as given in IS: 3658-1981 ‘Code of practice for liquid

penetration flaw detection (first revision)’ or magnetic particle inspection as given in IS : 7743-1975

‘Recommended practice for magnetic particle testing and inspection of steel forgings’ and also as explained in

fig below.

Fig. Ultrasonic testing of roller shaft

Fig. Magnetic particle inspection on roller shaft

Fig. Ultrasonic and magnetic inspection of roller shaft

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Chapter 5

FITTING OF SHAFT IN THE SHELL

Process:

Shrink fitting is used to fit the shaft into the shell.

Kerosene burner:

Burner can give heat at temperature ranging between 250 to 300oC. Shell is kept in the burner and heated to a

temperature between 250 to 300oC degree. At that temperature shell becomes red hot i.e. malleable in nature.

Then the shaft is lifted and inserted into the hole of the shell. Due to heat, the internal diameter of the shell

increases and gives some allowance so that the shaft enters into the shell freely. Then it is cooled, due to

solidifying it fits to the shell forming a shrink tight fit. The process of shaft in the shell i.e in the kerosene

burner can be seen in the figure below:

Chapter 6

FINAL OPERATIONS ON THE SHELL

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The following operations are performed on the shell after the fitting is done:

1. Facing

2. Turning

3. Grooving

1. Facing:

Facing is a turning process which involves moving of the cutting tool at right angles to the axis of rotation of

the rotating workpiece. This can be performed by the operation of the cross-slide, if one is fitted, as distinct

from the longitudinal feed. It is frequently the first operation performed in the production of the workpiece, and

often the last- hence the phrase "ending up". Due to facing excess length of the shell can be removed. Facing

operation for the shell can be seen in the figure below.

2. Turning:

Turning is the removal of metal from the outer diameter of a rotating cylindrical workpiece. Turning is used to

reduce the diameter of the workpiece, usually to a specified dimension, and to produce a smooth finish on the

metal. Turning is the process whereby a single point cutting tool is parallel to the surface. It can be done

manually, in a traditional form of lathe, which frequently requires continuous supervision by the operator. This

operation is one of the most basic machining processes. That is, the part is rotated while a single point cutting

tool is moved parallel to the axis of rotation. Turning can be done on the external surface of the part as well as

internally. Turning operation can be seen in the figure below in which irregular surfaces are being are turned

into plain surface as shown in figure below.

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After turning operation on the lathe, thus roller can be seen in the figure below:

3. Grooving:

Grooving is like parting, except that grooves are cut to a specific depth by a form tool instead of severing a

completed/part-complete component from the stock. Grooving can be performed on internal and external

surfaces, as well as on the face of the part (face grooving or trepanning).grooving is done by a single point

cutting tool while workpiece is rotated until a required depth of groove is produced on the shell. Grooves made

on the lathe can be seen in the picture below.

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Fig. Shell after the grooving operation

Scraper Plates:

These are the plates with teeth on one side which are introduced in between the roller, so as they can remove the

wastes (ie unwanted material other than sugarcane) in between the groves. After then the roller are taken to the

work shop. At which design are made on the shaft with manual work, with the help of using hammer and single

pointed tool. The completed roller finally can be seen below in the figure which is ready for use.

Workmanship and finish:

The shaft and shell must be free from holes, cracks, seams or other visual defects.

The shaft and shell must be machined properly.

Marking:

Each roller shall be marked with the following particulars:

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Manufacturer’s name or recognized trademark

Size (diameter and length)

Code and batch number

Packing:

Domestic orders are shipped directly to the sugar mill which has ordered for the roller, by means of a

flat-bed goods carrying lorry.

International orders are wrapped in a plastic sheet and are reinforced by wooden bars.

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