Theoretical and Experimental Studies of Uneven Dust Suction from a Multi-Cyclone Settling Tank in a Two-Stage Air Filter

Abstract

In this paper, the uneven air stream distribution problem of individual cyclones is studied in the multi-cyclones of intake air filters in special vehicles’ engines. This problem increases in multi-cyclones, in which several dozen cyclones have a common dust trap from which the collected dust is continuously removed by ejection suction. The aim of this study is the recognition of the theoretical and experimental possibility of reducing the streams’ unevenness, which should result in an efficiency increase in multi-cyclone separation. The methods that led to obtaining a relative stream uniformity from the suction of individual cyclones was analyzed. The method for creating equal pressure drops between the suction streams in the channels was used to achieve this goal. For this purpose, the internal structure of the multi-cyclone settler was changed. The multi-cyclone settling tank space was divided by vertical partitions into independent segments. The settling tank segment was then divided with horizontal shelves into suction channels of different heights, which were assigned a specific number of individual cyclones. The suction channels’ height was theoretically selected in terms of the equal resistance to air stream flow through the channels. For this purpose, the multi-cyclone dust settler segment model was developed. The theoretically determined suction channel’s height was verified by performing experimental flow tests in four (A, B, C, D) dust settler variants. Suction streams of satisfactory uniformity from the cyclones of the variant D settling tank were obtained at a level of 5%. In the next stage, experimental tests of the segment cyclones were carried out with dust before and after the division into suction channels of variant D for the settling tank. A significant increase was achieved from 93.73% to 96.08% in the cyclones’ separation efficiency, which were located as far away from the suction stub as possible and led to a reduction in the non-uniformity of cyclone efficiency in the segment. It follows that the multi-cyclone dust settling segment’s internal structure change gave the expected results.