Development of a novel harvester for grass seeds and cereal crops

Involves study of the grass seed industry in Central Queensland by conducting a market survey to determine the existing mechanisation in the seed industry and the problems faced by farmers. The main aim of the study is the design of an improved, effective grass seed harvester.. This research project sponsored by the Centre for Agricultural Technology(CAT) is seen as assistance to the Agricultural and Beef Industries which are among the major contributing industries to the Australian economy. The project involves a study of the grass seed industry in Central Queensland by conducting a market survey to determine the existing mechanisation in the seed industry and the problems faced by this group of farmers. The main aim of the study was to arrive at a design of an improved and more effective novel grass seed harvester, specifically designed by considering all the characteristics unique to grass seeds and the details which earlier research had indicated would help to increase the quality and the total yield, from the current 40-60% to about 80-95%. Earlier research on an air-assisted brush type of harvester indicated the problem of having to draw the seeds through the fan before separation. This seemed to cause trauma to the seeds which revoked the seed germination capacity. This research work has therefore been focused on designing a seed separator to be located ahead of the fan which could successfully separate the seeds of various shapes and sizes, from the large volume of conveying air required for suction, before entering the fan. A curved duct concentrator and a uniflow cyclone were selected as part of the experimental work and a theoretical approach was developed to understand and define the problems unique to the separation of the grass seeds. The results of tllese experiments and their comparison with the previous existing separators and harvesters have been discussed in this thesis. The technique for fan design for the harvester and finally the design specifications of a self driven harvester and a tractor mounted harvester were developed by incorporating all the harvester units, i.e the header unit, the separator and the fan.