design and fabrication of a maize de-husker

Description

Abstract

This study is on dehusking and shelling of maize under existing machineries or practices. On the basis of survey there is need of a compact dehusking cum shelling unit. A small portable single phase electric operated dehusker cum sheller was design and developed at SVCAET & RS with the help of M/s Punjab Agriculture Engineering, Dhamtari in year 2017-18. The portable medium size (600 kg/h capacity) electric motor (2.24 kW) operated Maize Dehusker cum Sheller was designed to resolve the issue by considering engineering properties of maize. The rectangular shaped machine having overall dimension length (610 mm), width (390 mm) and height (650 mm) made off up 35×35×5 mm angle iron. The selected operational parameters viz, cylinder peripheral speed (9 m/s), concave clearance (25 mm) and feed rate (600 kg/h) were studied for machine-performance and seed-quality parameters. The performance of machine under these parameters show the maximum dehusking was observed 99.00% with zero stalk cutting length at 10.63% moisture content, whereas 98.98% was found out at 1.91 m/s roller speed and at 800 kg/h feed rate. The minimum blower loss (1.37%) was obtained with roller speed (1.7 m/s) and at a feed rate of 600 kg/h. The maximum shelling efficiency (>98.86%) was obtained at cylinder speed of 7.35 m/s and feed rate of 800 kg/h at 14.12% moisture content. The minimum broken loss (0.63%) was obtained at 6.62 m/s cylinder speed and 12.14% moisture content. The minimum unshelled grain percentage was found as 1.04 at 6.62 m/s at 12.14%, cylinder speed and moisture content respectively. The seed germination percentage was found in the range of 91.12 to 95.79% for the developed maize dehusker Sheller. Overall machine performance was found satisfactory for maize dehusking cum shelling operation as well as to produce the maize grains for seeding purpose.

 

Keywords: Design, maize cob, dehusker, dehusking, and shelling

CHAPTER ONE

1.1 Introduction

Recently farmers have seen a shortage of skilled labour available for agriculture. Because of this shortage, the farmers have transitioned to using harvesters. Maize harvesting is one of the most important filed operations of maize production. One of the most important crop processing activities is threshing or shelling, which is used to extract the grains from the ear heads and prepare the quality for sale. Farmers must introduce advancements in technologies that meet their needs in order to increase their benefit from maize crop. Making maize crop into high-quality types not only increases farmers’ net profits, but also extends the useful life of maize products. (Nwakaire et al., 2011). Maize cobs are manually plucked by hand, and then harvested cobs are dried in the open yard to reduce moisture content by up to 15% to 21% (db). The common shelling and dehusking methods, such as rubbing crop cobs against each other, rubbing on bricks, stone, and wire mesh with an iron cylinder, are time- consuming and drudgery, and crop exposure to natural hazards such as rain, fire, livestock, birds, and insects over time results in losses in quantity and quality of grains. (Naveenkumar 2011). Dehusking is removing the outer sheath and shelling for kernels from ear heads are also part of maize harvesting. Dehusking is the process of separating the husk from the ear head without damaging the seeds, and shelling is the process of removing the maize kernel from the cob. (Oriaku, et al., 2014)

A maize dehusker could be develop, considering the following facts. It should be portable easy to carry from one place to other, electric power operated, as source of power cheap and pollution free, according to crop characteristics and system parameters (Dula, 2019). The machine could have a capacity of 500 to 800 kg per hour, with optimal dehusking efficiency, and is best suited for marginal, small and medium farmers.

1.2                                   PROBLEM STATEMENT

Traditionally, dehusking process of maize is done manually by labour and it consumes time and at the same time wastes maize. The purpose of mechanized maize harvesting is to replace manual labor to dehusk maize from fields in time with minimum loss while maintaining high quality.

1.1     AIM AND OBJECTIVES OF THE PROJECT

The main aim of this project is to design and fabricate a machine that will eliminate the skilled operator involved in de-husking the maize and to completely automate the dehusking and crown removing process. The objectives are:

1. To design a maize dehusking machine
2. To fabricate the maize dehusking machine

• To improve number of cobs produced per hour

1. Reduction of human
2. Reduction of manpower
3. Improvement on number of nuts processed per

1.2                     SCOPE/LIMITATION OF THE PROJECT

The scope of this work covers fabricating a maize dehusking machine which A dehusker removes the husk from cob and this is done with the help of two rubber roller rotating in opposite directions and at different speeds, the difference of surface speeds of two rubber rolls develop a shearing force on cob surface resulting in the opening and breaking of husk. Similarly surface of the rubber rolls rotating at lower speed tries to hold the cob but the faster rubber roll pushes the grain resulting in shelling of breaking of husk.

1.3     ECONOMIC IMPORTANCE OF THE PROJECT

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

iii) industries that might be using extracts from for other productions etc.

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

1.5                         CONTRIBUTION TO KNOWLEDGE

There are many existing ways of dehusking maize starting from traditional way to mechanical means. Some of these methods are time consuming, tiring, and difficult operation to perform and involves much human drudgery. Dehusking with traditional hand tools like machete or a spike depends on the skill of worker and involves training. Nowadays there is shortage of such skilled workers. The mechanized or the power operated machines are developed to eliminate the drawbacks of manual tools. Using this method serves as a means of eliminating the above mentioned drawbacks of the existing tools and machines.