ABSTRACT

Generally coconuts are dehusked manually using either a machete or a spike. These methods require skilled labour and are tiring to use. Attempts made so far in the development of dehusking tools have been only partially successful and are not effective in replacing manual methods. The reasons quoted for the failure of these tools include unsatisfactory and incomplete dehusking, breakage of the coconut shell while dehusking, spoilage of useful coir, greater effort needed than manual methods, etc. India is the 2nd largest producer of coconut in the world. Most of the farmers are not aware of the importance of coconut processing industry in India. Some projects were designed in recent times but the required target was not achieved.The manual de-husking involves high risk and consumes more time. To overcome this, there is a need to automate the de-husking process. Over decades many steps were taken to automate the de-husking process but all were in vain due to lack of knowledge and interest, fear for coconut shell breakage during the process, etc. Now it is the time to look into the great scope for the future in the field of agriculture. This machine will be great boon to the farmers and coconut vendors who always depend on labours for peeling the coconut.

CHAPTER 1

INTRODUCTION

Agriculture is the potential area that has to be automated which can be applied for activities like irrigation, harvesting, ploughing, weeding, etc. Our project aims at automating the process of removing the outer shell of the coconut by using some pure mechanical oriented thoughts. This machine is specifically designed to remove the husks from the coconut fruit using rotating blades to penetrate and effectively engage the husk portion of the coconut fruit. The interaction of the rollers in combination with the gripping action of the spike serves to tear away the husk from the nut leaving the nut intact.

The process remains safe and only one operator is required to operate this machine and there is no breakage of coconut. This coconut dehusking machine is more energy efficient compared to other machines. This serves an added advantage to our machine. The fibre production (both white and brown) in the country is estimated at 3.75 lakh tonne.Lack of an effective husk collection mechanism and consequent inadequate raw material availability is the main bane of the coir industry affecting its development. Meanwhile, the husk available with the small holdings, are now wasted in the absence of an organized system for collection of husk and its mobilization for being supplied to the industry.There is a shortage of fibre as the industry is able to use only 35 per cent of the 13,000 million coconut husks produced in a year.

CHAPTER 2

OBJECTIVE

The coconut processing industry has a booming scope in the market. The utilization of byproducts also plays a key role in the coconut processing industry. While evaluating the study undergone, the coconut dehusking remains unsolved due to failures. This project is a prototype of the de-husking machine where all the factors are considered like:

Cost factor

Energy efficiency

Safety factor

Time factor

2.1 ASPECTS TO BE CONSIDERED IN THIS PROJECT:

The aspects that have to be considered while fabricating this project are

1. Size of the coconut,

2. The usefulness of husk after peeling and

3. The use of coconut shell (as fuel)

4. Strength of coconut husk

2.2 REASON FOR UNDERTAKING THIS PROJECT

India being the largest producer of coconut, lack in technology of processing industry. Most of the farmers are not aware of the importance of coconut processing industry in India. Even now in dehusking the coconut the basic conventional process are being followed. Even though they face many problems in the field of agriculture, many blame their fate and no one takes action to solve their problems. Since the byproducts have a very good market in other industries like food, fuel and coir industry, which now is considered to be the booming field in agriculture. The outer shell (husk) of the coconut is removed for various purposes like extraction of oil, coir products, preparation of food items, etc. Until now the shell from the coconut is removed manually. The manual dehusking involves risk due to injury and consumes more time to dehusk (peel) the coconut shell and labour fatigue. This leads to less productivity and more labor cost.To overcome this, there is a need to automate the dehusking process.While automating the process the usefulness of the by-products are to be considered.

CHAPTER 3

BY PRODUCTS

Some of the byproducts of coconut are:

The nut

The shell

The coir

3.1 The Nut:

It is used in food processing industry and is most commonly used in home made foods, sweets, etc. Coconut oil is also extracted from the nut (dried) which is also used as hair oil and used even in cooking. The waste of coconut after extraction of oil is used as food for cows.

3.2 The Shell:

In ancient period the shell was used as weapon by people. Even now the shell is used as a fuel in many small scale industries due to high carbon content. It is normally used in houses of rural areas as cooking fuel. Now a day the shell is used in modern paintings and carvings.

3.3 The Coir:

Though the coir industry predominantly works on traditional finished yarns for ropes, matting and carpets, new avenues have emerged for the use of coir in the manufacture of panel boards as replacement to timber, side walls, floors and train seats. The coconut pith is used as soil former and agricultural nutrient. In Tamil Nadu, Karnataka and Andhra Pradesh, coconut husk was extensively used as fuel by the brick industry and sugar mills

CHAPTER 4LITERATURE SURVEY

We studied various methods of dehusking like;

1.The manual traditional process

2.The roller type blade mechanism

3.Imported hydraulic dehusking machine

4.1 The Manual Traditional Method:

The manual dehusking involves risk due to injury and consumes more time to dehusk (peel) the coconut shell. This leads to less productivity and more labor cost. In day today life the labour for peeling coconut is 16paise/coconut. Therefore for 1hour the labour is around Rs. 40/person. At the end of the day the cost for the labour itself touches 400/labour. Now for peeling of coconut its not just one labour is enough, we need at least 3 persons for peeling 1000 coconuts. The output is so poor that only averages of 200 coconuts are peeled off by one labour. Also due to labour fatigue the output further decreases.

4.2 The Roller Type Blade Mechanism:

The roller type mechanism is that two rollers each having an elongated configuration are disposed in spaced apart, substantially parallel relation to one another on the base and in readily accessible relation. A drive means is provided also in supported relation on the base and in direct driving engagement with the rollers.Interconnection of the rollers to the drive means is such that the rollers are forced to rotate in an opposite direction relative to one another and, in a preferred embodiment to be described in greater detail here in after, at relatively different speeds. Collectively, the rollers define two outer exposed surfaces which may be considered the upper portions of the roller.In such an orientation, the rollers rotate in a direction towards the center such that a coconut, placed thereon, will be forced into the spacing between the rollers. But the operator or the labour has to hold it to the center of the rollers till the roller catches hold of the coconut. This risks the labour to accident.And it is not energy efficient.

4.3 The hydraulic dehusking machine:

There are many hydraulically operated coconut dehusking machine available in the market which are used to remove the outer coconut husk from the coconut fruit. They are capable of dehusking 350 pieces of coconut fruit per hour with a single operator.Basically these hydraulically operated machines require more care and maintenance. They are reliable to certain extent because they cause breakage during the operation.The operation involves skillful labour who has to know the hydraulic components working and must be properly trained to operate and maintain it. More over the machine is much more expensive that iscannot be afforded by normal person. The technology involved in this machine also complex and inaccessible.

CHAPTER 5

COMPARISON TABLE

BASIC WORKING PRINCIPLE:

The power from the 1hp motor is transferred through a v-belt-pulley arrangement to the shaft on which the blades are arranged. There are two such shafts which rotate in the opposite direction, each containing four blades on it. The two shafts are rotated using two gears positioned on each shafts with same number of teeths. The coconut is placed in between the teeths of the shaft so that when pressure is applied from the top, the coconut gets engaged in the blades and the process of dehusking occurs. The expected number of coconuts to be dehusked by this machine is 900 coconut per hour.

DESIGN OF COMPONENTS.

DESIGN

DEHUSKING FORCE CALCULATION

Dehusking force= 8 Kgf ( tender coconut)

= 10 Kgf(dry coconut)

BEARING:

F=10Kgf

S=1.2(service factor)

Equivalent Load (P) =FS

=101.2 =12Kgf

Dynamic capacity , (K=3 for ball bearings.)

Life of bearing(L) = = 175.2 million revolutions C = 401.1 Kgf

Bearing selection: Self aligning ball bearing

SKF NO:2206 ,d=30mm, D=62mm, static capacity()=560Kgf,

dynamic capacity(C)=1200kgf, maximum permissible speed=13000 rpm.

PULLEY AND V-BELT DESIGN:

D =75mm, N =200rpm

D =id = 3.675= 270mm

equivalent pitch diameter (De) =85.5mm

Belt cross-section symbol is A

Belt speed (s) =(DN)/60 =2.356 m/s

Rated power for belt cross-section A =1.559 KW

Design power = (rated power service factor)/(lengthFactorangle correction factor)

= (1.5591.11.02)/(0.97) = 1.803 KW

Number of belts = design power/rated power = 1.15

1

Centre distance(C) =700mm

Length of belt = =1872mm

Top Width of belt = 13mm

Thickness= 8mm

DIMENSION OF V-GROOVED PULLEY:

Groove cross-section=A

Pitch width=11mm

Minimum depth below pitch line=8.7mm

Edge of pulley to first groove centre (f)=10mm

POWER REQUIREMENT

Power,

=

= 205.46 W

= 0.27 hp

Hence , 1 hp slow speed motor is selected

SHAFT DESIGN

=

The diameter of shaft selected is 7 cm.

SLOPE DESIGN

Coefficent of friction for coconut= 0.522

For coconut to slide =

Selected value of slope = 28.072

MACHINE COMPONENTS

The main components of the machine are as follows:

Machine frame

Drive mechanism

Holding mechanism

Blades

MACHINE FRAME

DRIVE MECHANISM

The drive mechanism plays a vital role since the complete operation is mechanically oriented.It consist of: A motor

Pulley arrangement

Shaft with blades

Bearings

Gears

THE MOTOR:

A single phase AC 1hp slow speed induction motor is used to drive the machine. The motors output shaft is connected directly to the pulley arrangement. The motor bed is rigidly fixed to the frame of the machine. The speed of the motor is 960 rpm.

PULLEY ARRANGEMENT

This arrangement transmits power from the motor to the rotating shaft. It consists of two pulleys and a V belt providing a speed reduction of 4.8.

Dimensions:

SHAFT WITH BLADES

Two rotating shafts of diameters 30cm are provided with blades for the peeling action. Each shaft consists of four blades. These shafts rotate in the opposite direction with same speed.

Dimensions

BEARINGS

Bearings are provided to support the shafts and also to maintain a smooth rotation of the shafts. The bearings used in this machine are self aligning ball bearings and they accommodate any misalignments in the shaft.

Dimensions

GEARS

Gears are used to rotate the two shafts with same speed and in opposite direction. The gears used in this machine are spur gears.

Dimensions

HOLDING MECHANISM

BLADES

MATERIAL USED:

Mild steel

COST ESTIMATION

Material cost:rs 2000/-

Bearing cost:rs 1250/-

Motor cost:rs 2000/-

Belt and pulley:rs 2500/-

Gears:rs 1500/-

Manufacturing costs:rs 7500/-

Other costs:rs 1250/-

Total cost estimate:rs 18000/-

RESULT

CONCLUSION