Thesis Abstract

Abstract
The design of a melon de-husking and separation machine is essential to improve the efficiency of melon processing in agricultural settings. Melons are popular fruits with high water content and nutritious seeds, but their tough outer husks make manual de-husking a time-consuming and labor-intensive task. This research project focuses on developing a mechanized solution to automate the de-husking and separation process for melons, enhancing productivity and reducing the physical strain on farm workers. The machine design incorporates elements such as a feeding mechanism to introduce melons into the de-husking chamber, rotating blades or rollers to remove the outer husk, and a separation system to isolate the seeds from the pulp and husk debris. The de-husking mechanism is optimized to minimize damage to the seeds while efficiently removing the tough outer husk. Additionally, the separation system employs methods such as air blowing, sieving, or gravity separation to achieve clean seed extraction. Key considerations in the design process include the size and shape variability of melons, as well as the need for adjustable settings to accommodate different melon varieties. The machine is designed to be user-friendly, with simple controls and maintenance requirements to ensure practicality in agricultural operations. Safety features are also integrated to protect operators from potential hazards during machine operation. The efficiency of the melon de-husking and separation machine is evaluated through performance metrics such as processing capacity, de-husking effectiveness, seed purity, and energy consumption. By automating the de-husking process, the machine aims to significantly reduce processing time and labor costs while improving overall yield and seed quality. The design is optimized for durability and reliability to withstand the rigors of continuous operation in agricultural environments. Overall, the development of a melon de-husking and separation machine offers a promising solution to enhance melon processing efficiency and productivity for farmers and food processors. The mechanized approach not only streamlines the de-husking process but also ensures consistent seed quality and reduces reliance on manual labor. Future research may focus on further optimization of the machine design, as well as potential adaptations for processing other fruits or vegetables with similar de-husking requirements.

Thesis Overview

INTRODUCTION

     Nigeria is an agricultural nation. Melon (Citrullus Vulgaris) is widely cultivated in Nigeria, among other seedlings during the planting season yearly. Several tones of the melon seeds are gathered each harvesting period but only very low percentage of the total harvest are dried by atmospheric draught and bagged for storage. High percentage waste is encored due to lack of good processing and storage facilities.

Melon when properly processed yields a lot of by-products, which could be used as food or as raw material for small and large scale industrial manufacture melon is highly enriched with oil. It has about 45% oil content. The oil could be extracted to form a very good source of vegetable oil.

After pressing out the oil, the remaining product can be used as food for human of as an additive in agro-feed manufacture. Melon without oil can be grounded and used as thickener or binder in the chemical and pharmaceutical industries.

The outside shell of the melon seeds when properly harvested in large quantity can equally be used in preparation of agric feed. The shell has about (12-55) MJ/kg calorific value and therefore can be used as a source of energy for industrial use.

The major problems encountered in the processing of melon seeds are the removal of the yellow outside shell and the separation of the broken shells form the white seeds. Locally as at now, manual approach is used for the de-husking and separation. The consequence of this is low productivity, increase in processing time, and increase in human labour.

A mechanized method of de – husking and separation will definitely increase productivity, reduce processing time and bring down human labour input to the minimum.

These problems arising form the manual de-husking and separation of the melon white seed from the shell necessitated the idea of designing, constructing and testing a melon de-husking and separation machine for our local communities and industries.

1.2 DESCRIPTION OF THE DESIGNED MELON

    DE-HUSKING AND SEPARATION MACHINE

The assembly drawing of the designed de-husking and separation is shown in appendix.

The machine consists of the following components namely.

• Impeller
• Inlet hopper
• De-husking casing
• Inlet channel
• Casing cover
• Chequer linings
• Exit channel
• Adapter
• Blower

10) Electric Motor

11) Structural Stand

12) Blower Casing

13) Blower Impeller

14) Blower Casing Cover

15) Blower Suction Channel

16) Air exit channel

17) Blower mounting base

18) Flange bearings

19) Bolts and Nuts

20) Blower shaft

The de-husking impeller is housed by the de-husking casing. The casing is lined with cylindrical chequers. The cylindrical impeller is mounted very closely to the inside walls of the cylindrical casing leaving a minimal gap to contain the melon seeds as they flow through this gap from inlet channel to the exit channel. The casing is covered with a cover plate. The impeller is connected to the shaft of the electric motor through an adapter. The blower impeller is housed by the blower casing. The blower sucks air from outside through the suction channel and the impeller forces the air through exist channel as required. All the arrangements of the machine are carried by the structural base. Bolts and nuts are used to ensure proper mounting of components on the structural base.

1.3 PRINCIPLES OF OPERATION          

The principle used by this machine to achieve the melon de-husking is attrition and density differential between the cracked shells and the white seeds is applied to achieve the required separation.

The electric motor provides the primary motion which rotates the de-husking impeller. The melons are introduced through the inlet hopper of gravity. The melons are directed to flow towards the walls of the casing to the chequers. The rotating impeller then rub the melons on the chequers in the direction of rotation of the impeller. The melon must be properly treated with water (moisture) arieated properly before de-husking.

The rubbing action peels the shells of the melons and equally move them along with the broken shells in the direction of rotation to the exit channel.

        The blower shaft transmits motion from the electric motor to the blower impeller, thereby delivering certain quantity of air which is channel to meet the broken shells and white seeds coming out from the de-husking casing.

The broken shells being lighter than the white seeds are carried away by the air to a different direction while the white seeds move into a receiver where they are collected.

1.4 ADVANTAGES

1. i) The machine combines two processes in one ie de-

Husking and separation.

1. The machine is portable and occupies

very little space.

1. The machine is cheap when constructed locally,

compared to cost of importation.

1. The machine can be confidently be driven by a

single phase electric motor thereby making power

consumption rate very low.

Vi. De-husking and separation time is highly

reduced by using this machine.

vii. Labour input in de-husking and separation is also

drastically reduced.

viii. Productivity in de-husking and separation is

highly increased.

1.5 OBJECTIVE

(i) The objective of this project is to design, fabricate and test a melon de-husking and separation machine in order to increase productivity in melon processing and reduce human labour of manual de-husking and separation to the bearest minimum.

(ii) This project will improve the living standard of million of rural dweller who may engage in melon processing.

(iii) It will encourage the growth of small and medium scale industrial enterprise in the agric – processing nation wide.

(iv) This project will contribute to the overall economic development of the nation by encouraging indigenous engineers technologists and technicians in designing, fabricating and testing of processing machines.

1.6 SCOPE

This machine only handles treated melon. The designed machine is expected to de-husk and separate about 450 kg of melon in an hours work. This is result in about 3, 600kg or 3.6 tonnes in eight (8) hours work.

1.7 BENEFICIARIES

1. i) The major beneficiaries of this project are rural dweller who might engage themselves in melon processing.
2. ii) Small, and medium scale agro-industrial set up who produce products like vegetable oil and food items.

iii) Chemical and pharmaceutical industries who might be using extracts from melon as binders, thickeners for drugs etc.

1. iv) Agro – feed industries who might be using melon as additive in feed production.