Design modification of seed distributor of pneumatic seeder for corn sowing

Abstract

A feature of the pneumatic sowing machines is to mount the opener sowing apparatus. Analytical studies of serial row planters have found that the free fall of seed from the sowing apparatus to the bottom of the furrow leads to spreading seeds, both along and across the furrow. The spread worsens crop uniformity and lowers the yield. To overcome this limitation it is necessary to reduce the height and angle of the seed fall, the magnitude and direction change their speed at the time of reset. This study designed a sowing unit with seminal duct, having accelerator of seed. The regularities of seed movement in the seminal duct pneumatic sowing machine with the influence of the speed of aggregate movement are substantiated. The factors that allow the seed to reach the speed at the exit of the seminal duct, equal to the rate of seed unit are: the air speed in an accelerator, the accelerator length, the angular speed of the seed disc. The parameters and operating modes of the sowing machine, equipped with the seminal duct with the accelerator: the inner diameter of the seminal duct is 16 mm, the height of the start and end sections of 0.14 m, 0.01 m; the radius of curvature of the second portion of the seminal duct is 0.076 m, the angle of descent of the seeds with the seed disc - 200, the accelerator length - 0.12 m, the angular speed of the seed disc 2.5-3.0 s-1, the air flow rate in the accelerator 18...20 m.s-1. The experimentally determined average interval between sowing seeds of corn at a pneumatic device with the seminal duct without accelerator totaled 342 mm, with the vas deferens with the accelerator - 304 mm; the coefficient of variation was 41.4 % and 38.8 %; percentage of seeds at intervals in the prescribed initial requirements is respectively 52 % and 92 %. Using of the seminal duct with the accelerator allows to manage the process of delivery of seeds from the seed unit to the bottom of the furrow with the seed feed rate at the output of up to 3.5 ms-1.