DESIGN OF AUTOMATIC COCONUT DESHELLER

DESIGN OF AUTOMATIC COCONUT DESHELLER

ABSTRACT:

Coconut plays an important role in the economic, social and cultural activities of millions of people in our country. India is a major producer of coconut in the world. Coconut provides food, edible oil, industrial oil and health drink to humanity. Coconut oil, which comes under edible-industrial group, is used as a cooking oil, hair oil, massage oil and industrial oil. Coconut oil can be blended with diesel, straight in an adapted engine or turned into biodiesel. India has unbeatable quality advantage in this sector. Refined coconut oil is mainly used in the manufacture of biscuits, chocolates and other confectionery items, ice cream, pharmaceutical products and costly paints.

In order to obtain the oil from the coconut, there are number of process to be done. The processes are coconut plucking, dehusking, breaking shell, drying, deshelling the kernel from the shell and finally extracting the oil from the kernel. In the above process, the time consuming is the coconut deshelling, since it is done by using manual labours. Most of the regions use manual deshelling at present. The coconut is deshelled by means of using knifes, hooks, etc. Due to manual process, time is consumed, other major disadvantage is the labour problem and by using the external devices there may be a chance of accidents takes place. In order to avoid such kind of difficulties we go for the automation process. The objective of the project is to deshell the kernel from the coconut.

The ‘Automatic Coconut Desheller’ system which concerns about the deshelling process of Cocos nucifera (coconut) for oil extraction process is introduced. It consists of three parts, they are conveyor and clamper unit, stepper motor with blade setup and double acting cylinder. In this automatic coconut deshelling machine the dried coconut is automatically loaded in the gravity feed mechanism clamper setup and the kernel is removed from the shell by means of specially designed blade which is attached to the double acting cylinder with stepper motor arrangement. Thus the shell and kernel are collected separately by using AUTOMATIC COCONUT DESHELLING machine. Thereby reducing the  human intervention in the process of deshelling the coconut. Thus  reducing the labour wages and time consumption.

INTRODUCTION:

                Coconut plays an important role in the economic, social and cultural activities of millions of people in our country. India is a major producer of coconut in the world. Coconut provides food, edible oil, industrial oil and health drink to humanity. All parts of coconut tree is useful in one way or other and the crop profoundly influences the socio-economic security of millions of farm families. Coconut oil, which comes under edible-industrial group, is used as a cooking oil, hair oil, massage oil and industrial oil. Coconut oil can be blended with diesel, straight in an adapted engine or turned into biodiesel.

Now a days the shell and kernell are removed manually using knife and hooks. Automation results in reduction of human effort and improves productivity of the industry by leaps and bounds. The ‘Automatic Coconut Desheller’ preheats the partially dry coconut (reducing drying time), deshell the kernel. 

 PROBLEM DEFENITION:

At present the deshelling process is performed manually. Insufficient labour strength, skillful work requirement makes the process tedious and time consuming. There are chances of accidents during manual process. The labour cost also collectively adds up to the cost of the product. The problems like time consumption and labour insufficiency can be overcome by automating the process.

SCHEMATIC DIAGRAM:

                                  Fig : Schematic Diagram

BLOCK DIAGRAM:

                                         Fig : Block Diagram

OVER ALL VIEW OF THE PROJECT:

Fig : Over all view of the project

DESIGN PROCEDURE:

                The design of the project consists of the following steps

1. Design of blade

2. Selection of cylinder and solenoid

3. Design of clamper

4. Selection of sensor

5. Selection of stepper motor

6. Programming Microcontroller

7. Design of Relay

8. Power supply circuit

9. Conveyor design

COMPONENTS USED:

                The main components used in the project are

1. Pneumatic Supply

2. Double Acting Cylinder

3. Blade Setup

4. Clamping Setup

5. Conveyor Setup

6. Proximity Sensor

7. Stepper Motor

8. Microcontroller

9. Relay Circuit

10. Power Supply

The objective of the project is to deshell the kernel from the coconut. The above mentioned components are integrated together to achieve the objective of the project. Thereby reducing the human intervention in the process of deshelling the coconut. Thus reducing the labour wages and time consumption.

PNEUMATIC SUPPLY:

COMPRESSOR:

Fig : Positive displacement compressor

SPECIFICATIONS OF THE COMPRESSOR:

Table : Specification of compressor

Motor	3 HP
Tank Capacity	250 liters
Work pressure	12 kg/cm2
Displacement	310 lts/mm
RPM	720 rpm

DOUBLE ACTING CYLINDER:

                A "double-acting" cylinder as shown in fig 3.4 has two ports through which the supply of air is reversed to cause displacement in either direction. The general specification for a pneumatic cylinder is in terms of the bore diameter of the cylinder, the stroke length of the piston and the maximum operating pressure range.

Fig :  Double acting cylinder

To return the piston to its resting position, not only apply pressure to the second port, but also open up the first port so that the gas in it can be expelled. In this project double acting cylinders are used for the obtaining upward and downward movement of the blade setup.

Table : Specifications of Double Acting Cylinder

PARAMETER	VALUE
Make	JANATICS
Stroke Length	160mm
Bore Diameter	40mm
Max Pressure	20 bar

Fig :Schematic representation of Double acting cylinder

Fig : Double acting cylinder with stepper motor and blade

BLADE SETUP:

        The blade with ‘S’ shaped hook as shown in fig 3.9 is used for deshelling the coconut. The thickness of the blade is 1 cm. The blades are having the diameter of 7cm. The fixed blade is mounted to the rotor spindle of stepper motor at 90-degree angle for easiest removal of the kernel due to ‘twist and pierce’ action. The blade setup is fixed to the stepper motor, when the stepper motor provides the rotating motion it causes the rotating movement in the blade to seperate the coconut shell and kernel.

               

Fig : Blade with proximity sensor

                The specifications of the blade used are,

Corrosive resistant steel

n  Tensile strength  = 630 N/mm²

n  Yield strength     = 480 N/mm²

n  Brinell hardness number = 241

n  Heat treatment

               Heated to 1000°C, Air cooled and tempered at 600°C.

                                    

Fig : Front View of Blade Setup                                                       Fig : Top View of Blade Setup

CLAMPING SETUP:

          Clamping mechanism plays an important role in the project because the clamping and declamping need not involve any human assistance. Therefore considering above criteria it is decided to use ‘Gravity Feed Mechanism’ for the clamping purpose.  As shown in figure clamping setup consists of two shells one of which is fixed and the other is movable one. A weight is attached to the movable shell of the clamper through a lever.

                The clamping setup as shown in fig 3.12 is attached to the conveyor, it moves along with the conveyor. When the clamping setup is loaded with the dried coconut, due to the gravitational force acting over the weight the clamper holds the coconut shell tightly. After the deshelling process is over, the clamping setup reaches end of the conveyor and it becomes upside down so that the clamp releases the coconut shell, which falls into the collecting basket.   

                                            

Fig : Front view of clamper               Fig : Top view of clamper

Fig : Clamper with shell

 CONVEYOR DESIGN:

CONVEYOR SETUP:

                A belt conveyor consists of two or more pulleys, with a continuous loop of material - the conveyor belt - that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The belt consists of one or more layers of material they can be made out of rubber. Many belts in general material handling have two layers. An under layer of material to provide linear strength and shape called a carcass and an over layer called the cover.

• Available in different widths and lengths to suit customer requirement. These may be flat belt type, toughed belt type and even cleated belt type. Belt conveyors are used in conveying powdered material or bulk material. They are also extensively used in packing lines, assembly lines, inspection lines. In certain applications metal detectors can be coupled to belt conveyors which facilitate online inspection and avoid any metal particle to remain in the material. These also find good application in conveying material to a long distance.
• Automation Systems has developed special belt conveyors wherein material can be transferred in 90^o and even 180^o.

BELT CONVEYOR ADVANTAGE:

A belt conveyor has the advantages of simplicity of construction, high efficiency and low frictional loss resulting in low power requirements and economy in upkeep. It may be horizontal or inclined or a combination of both and can be arranged to convey material up or down an incline.

Fig : Belt conveyor with clamper

PROXIMITY SENSOR:

                Inductive proximity sensors as shown in fig 3.15 are widely used in various applications to detect metal devices. They can be used in various environments (industry, workshop, lift shaft...) whenever high reliability is required.

                Inductive proximity sensors generate an electromagnetic field and detect the eddy current losses induced when the metal target enters the field. The field is generated by a coil, wrapped round a ferrite core, which is used by a transistorised circuit to produce oscillations.

Fig : Proximity Sensor

The target, while entering the electromagnetic field produced by the coil, will decrease the oscillations due to eddy currents developed in the target. If the target approaches the sensor within the so-called "sensing range", the oscillations cannot be produced anymore, the detector circuit generates then an output signal, which controls a relay or a switch.

STEPPER MOTOR:

                A stepper motor is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps, for example, 200 steps. Thus the motor can be turned to a precise angle.

POWER SUPPLY:

Block diagram:

               

                The ac voltage, typically 220V rms, is connected to a transformer, which steps that ac voltage down to the level of the desired dc output. A diode rectifier then provides a full-wave rectified voltage that is initially filtered by a simple capacitor filter to produce a dc voltage. This resulting dc voltage usually has some ripple or ac voltage variation.

A regulator circuit removes the ripples and also remains the same dc value even if the input dc voltage varies, or the load connected to the output dc voltage changes. This voltage regulation is usually obtained using one of the popular voltage regulator IC units.

Fig :Block diagram of Power supply

SYSTEM DESCRIPTION:

The dried coconuts are collected and they are placed in the clamping setup one by one. The loaded clamper setup moves along with the conveyor. When the clamping setup approaches the proximity sensor, the conveyor stops moving and the double acting cylinder gets actuated. As the double acting cylinder moves down, stepper motor starts rotating so that the blade attached to it rotates piercing into the kernel and made a rotation to separate the kernel from the shell. Then the double acting cylinder retracts so that the blade moves up along with the kernel thus separating the kernel and shell. After deshelling process the clamper with empty shell starts moving in the conveyor, when top portion of conveyor becomes downwards, so that using the gravity feed mechanism does the declamping process. Then with empty clamper is moved and is get ready to load for the next shell.                                                                                                                            

                                         Fig: System Working

RESULTS:

                By practically we have made cost analysis from the small scale industries, by means of manual deshelling process the time taken for deshell one coconut is nearly about 2 minutes and by using this machine the time taken is 10sec per coconut to deshell. The cost for deshelling 100 coconuts by manually is about 35 rupees, by means of using this machine we can reduce the amount as compare to the manual process.

Table: Cost Analysis

SL.NO.	COMPONENTS	COST (approximately)
01	Conveyer Belt + Rollers	1,500.00
02	Stepper Motor	500.00
03	Microcontroller (8051 Family)	500.00
04	Circuit Construction	1,000.00
05	Mechanical Design	4,000.00
06	Double Acting Pneumatic Cylinder	2,000.00
07	Blade Setup	500.00
	TOTAL	10,000.00

 CONCLUSION:

               

                Thus a low cost automated project has been implemented in the field of coconut based oil industries to reduce the manpower completely and to increase the productivity.

SCOPE FOR FUTURE WORK:

The implemented Automatic Coconut Deshelling Machine can be made further advanced by the following ways

·         Spring arrangements can be made for accommodating coconut of different sizes.

·         Separate collecting box can be used, one for collecting the kernel and the other for the shell.

·         Proper weighing setup is used to weight the shell and kernel separately.

·         Solar heater can be attached, so it reduces drying time and the deshell process can takes places even in the winter season.

REFERENCES:

1.                   Anthony Espasito (2000) “Fluid Power with Applications”, Pearson Education., Sixth Edition.

2.                   Jack.D.Lane, Society of manufacturing Engg. Michigan, (1986) –“Automated Assembly”.

3.                   Dr.Radhakrishnan.V professor, IIT, Madras. Engg. Staff college of Hyderabad. (1986) – “Assembly and Assembly Automation”.

4.                   Thereja.B.L (2000), “Fundamental of Electrical Engineering and Electronics”, S.Chand and Company Pvt.Ltd, First Edition.