农用拖拉机、谷物联合收割机等作业时,作业场所周围的环境一般都比较恶劣,风沙和粉尘较多,干旱季节更是如此,尤其干旱少雨的风沙区更为严重.拖拉机进行耕、耙地、谷物联合收割机进行小麦收割等作业时,因作业机械高速旋转与被加工对象接触,使土壤或物料破碎而产生大量粉尘,随高速旋转的机械四散飞扬,再加上拖拉机轮胎因打滑抛起的粉尘,致使作业机组周围空气被污染 Agricultural tractors, grain combine harvesters and other operations, the environment around the workplaces are generally harsh, wind and dust more, more so in the dry season, especially in the arid and dry windy and sandy areas more serious tractor farming, harrowing, Grain combine harvester for wheat harvesting and other operations, due to high speed rotation of the working machinery with the object to be contacted, so that the soil or material broken produce a lot of dust, with high-speed rotation of the machinery scattered flying, coupled with the tractor tires due to the skid thrown Dust, causing the air around the operation unit is polluted