【摘要】 本文从理论上分析了种子在气流管道中的运动规律,采用电测的方法,对八种农作物种子、十种不同形式的气流输种管道,在各种气流速度 Ua 下进行试验。结果表明:(a)在直管中,种子运动速度的变化规律和理论分析基本一致;(b)在弯管中,种子速度呈指数函数衰减;(c)输种管倾角小时,Ua 增大,输种均匀性提高;倾角大时,Ua 过大或过小都不利均匀输种;(d)Ua 较小的情况下,弯管半径对输种均匀性影响很大,当 Ua>18.5m/s 时,影响并不显著;(e)水平→水平形式弯管输种均匀性最差;水平→垂直上升和垂直下降→水平这两种形式输种均匀性较好。更多还原

【Abstract】 This paper describes the moving regularity of seeds in the pneu- matic pipes theoretically.Electric determination is adopted.Seeds of 8 crop varieties and the pneumatic pipes of 10 different types are tested under the different velocities(Ua)of air current.Results indi- cate that(a)the varying regularity of the seed moving velocity is basically agreeable to the theoretical analysis in the wertical pneuma- tic pipe;(b)the seed velocity appears to be reduced in the exponen- tial function in the crooked pneumatic pipe;(c)when the inclination of seed conveying pipe is small,the velocity(Ua)of air current tends to increase,thus the uniformity of seed conveys is improved.When the inclination of seed conveying pipe is large,either too high or too low velocities are unfavourable to the uniformity of seed conveys; (d)when Ua is small,the radii of the crooked pipe might have a great effect on the uniformity of seed conveys,when Ua is more than 18.5m/s,the effect of radii of the crooked pipe on seed conveys is not significant;and(e)the uniformity of seed conveys by the crooked pipe from level to level is the poorest and that by the crooked pipe upward from level to vertical and downward from vertical to level is much better.更多还原