Study of seed corn threshing process

Abstract

A high yield of grain and green mass of corn can be obtained only when using the seeds of the first generation of zoned hybrids, which are threshed in the conditions of processing enterprises after pre-drying the cobs to a humidity of 12…18 %. At this humidity, the strength of the shell of corn grains is maximal and the connection of the grain with the rod is weakened, which allows for threshing with minimal damage to the grain. An experimental design of an axial-rotary threshing device, which rotor is equipped with multi-helical spiral winding of variable height, is developed. The winding height decreases from the entrance to the threshing chamber to the exit from it. Rotor fully covered pneumatic-adaptive studded deck is installed so that the gap between the rotor shaft and the independent movable pins decreases from the input to the output. All pins are pressed against the deck by means of rubber pneumatic bags with an internal overpressure. In addition, the threshing chamber has the ability to change its spatial position relative to the horizon. These dimensional characteristics are justified foe a stationary axial-rotary threshing device with a productivity of up to 4.5 t•h -1 . As the result of experimental studies, the following rational intervals of values of the modes of operation of the threshing device were established: the rotor speed 150…170 min -1 , the angle of inclination of the threshing chamber 10…14º, the force of pressing the movable pins to the cobs 35…55 N, feed 0.8…1.1 kg•s -1 . As a result, the productivity of the axial-rotary threshing device is in the range 2.88…3.96 t•h -1 and the energy intensity of the threshing process is 0.5…0.7 kWh•t -1 , grain on the cob after threshing is less than 1.5 %, free grain in threshed corn cobs 1.16 %.

Factors, Harms, and Control of Corn Kernel Breakage: A Review

“…The threshing force exerted on the cob by too slow a rotational speed or too large a plate spacing will make it difficult to meet the threshing conditions, and too high a rotational speed and a small plate gap will exert too much force on the cob, resulting in excessive kernel breakage. When corn threshing is carried out, the drum speed, drum diameter, ripple spacing, concave plate gap, feeding volume and feeding direction of the threshing machine have an effect on the threshing efficiency and breakage rate [33], and the results of the study show that reducing the drum speed is the most effective way to eliminate or reduce the kernel breakage, but the reduction of the drum speed also reduces the efficiency of threshing work [34].…”

Сoncept of corn threshing by a rotary threshing-and-separating unit with an air curtain of the discharge port

“…Наличие заслонки выгрузного окна создает противоход части обмолачиваемой массы, что позволяет использовать более короткий ротор (на 10…15%) [2][3][4]. Кроме того, заслонка позволяет разрушать направленный воздушный поток, создаваемый лопастями ротора в конце молотильной камеры, что минимизирует сход свободным зерном в выгрузное окно.…”

Low-Damage Corn Threshing Technology and Corn Threshing Devices: A Review of Recent Developments

“…The size of the corn kernel, the surface shape of the corn kernel, and the arrangement of holes on the concave screen all impacted the threshing time of the corn kernel. In the subsequent study, Bakharev D. et al [47] designed an axial flow rotary threshing device. The concave clearance of this device decreased along the entrance to the exit direction of the threshing chamber.…”