SPEED OF GRAIN FALL IN A RISING AIR FLOW

Abstract

Parameters of the movement of wheat and oats seeds in the ascending air stream have been investigated. Laboratory installation with the vertical channel 50 × 50 mm square section which is able to fix air consumption has been used. Process of grain fall was videotaped that helped to observe the movement of purposefully painted grains. By processing the video recordings, the time span which grains need to pass the control site has been defined. The obtained data have allowed to determine the speed of grain fall at various speed of the ascending air stream. The inversely proportional dependence between the speed of falling of wheat and oats seeds with increase in speed of a vertical air stream in the range to critical is established (wool-gathering speed). Speed of the free fall of grains without action of the air stream was 1.145…1.313 m / s. The reduction in the rate of falling of wheat and oats seeds at various speed of the ascending air stream can reach 4.42…4.51 times in comparison with the speed of free fall of seeds and has to be considered when choosing the parameters of the corresponding processing equipment.

Table 1. Fig. 3. Ref.: 8 titles.