Improving the process of grain separation from the straw of a field machine for collecting not winnowed heaps

Abstract

Under market conditions in the agricultural sector, profitable production of crop products due to high prices for fuel and equipment is impossible without using resource-saving technologies. In the priority direction of development of agricultural production, a key place is given to the harvesting of grain crops. Research on combine technology has revealed its shortcomings: grain losses in the field exceed agrotechnical requirements; chaff is completely lost; complex design of harvesting machines and numerous technological adjustments. All this prompted the development of resource-saving cleaning technologies. The technology of harvesting with the collection of not winnowed heaps (small grain heaps) deserves great attention. A field machine which is manufactured on the basis of a grain harvester is used as a harvesting unit. It is planned to dismantle the grain tank and accompanying transport devices, the sieve frame, the straw filler and the chaff filler from the combine. A pneumatic conveyor is used to remove small grain heaps from under the threshing apparatus and grain passages from the straw walker. Not winnowed heap is transported by air flow to a tractor trailer running parallel or coupled with the field machine. The coarse heap from the threshing apparatus goes to a conveyor-key type straw separator. The novelty of the process of separating grain from straw lies in the fact that the coarse heap moves along the straw walker at a speed that ensures thin-layer grain separation, and the kinematic mode of the two-shaft conveyor-type straw walker is chosen such that the efficiency of grain separation is several times higher than that of a serial straw walker. A method for calculating the main parameters and dimensions of the conveyor-key straw walker of a field machine is presented: the speed of movement of the heap with a rake conveyor, the length of the fingers, and the length of the zone where straw flows from the fingers, the revolutions of the key shaft of the proposed straw separator.