Dust Abatement System for Wheat Thresher

Abstract

Wheat is the major cereal crop after rice in India. India s share is about 13 per cent of total worlds production of wheat. Threshing of the crop is carried out manually or mechanically with commercial wheat threshers or combines. The commercial wheat threshers when operated produce a sizeable amount of dust and the farm workers are exposed to it. The inhalation of such particulate matter has been established as the main route of exposure to organic dust that can cause adverse health effects. In order to curb this issue, three commonly used commercial wheat threshers with capacity 600, 800-1000 and 1200-1500 kg/h, were assessed for their particulate matter emissions. The mean dust concentrations of PM5 and PM10 were measured at the personal breathing zone of the workers feeding crop in the feeding chute and collecting threshed grains at the grain outlet of the thresher at the personal level exposure. Mean dust concentration of PM1, PM2.5, PM4, PM10 and TSP were recorded at three locations i.e., 3 meters left, right and back of the blower outlet of operating threshers at environmental level exposure. The thresher with capacity 800-1000 kg/h emitted the highest dust emissions at both personal and environmental level. Therefore, it was selected for the design and development of the dust abatement system. The integral part of developed dust abatement system (DAS) involved two divergent Stairmand high flowrate type cyclone separators of diameter 0.32 m, a bifurcating connection between the cyclone separators and the thresher blower outlet and the stand to support the assembly. The material of construction was MS sheet of 2 mm thickness both for cyclone separators and the bifurcating connection. Contd.....