Abstract
Improving rice threshing unit performance and structure significantly optimizes the thresher's overall efficiency by raising production per unit time while lowering costs and power consumption. This study introduced a new threshing device for rice combine (drum-shaped). It evaluated the threshing device performance using two threshers' structures under different rotating speeds of 1100, 1300, and 1500 rpm and feeding rates of 0.8, 1.1, and 1.4 kg/s. The studied parameters were evaluated through statistical analysis regarding thresher throughput, efficiency, seed damage, and specific energy. The experimental parameters greatly affected the whole performance of the threshing unit as the throughput, seed damage, and threshing efficiency positively correlated with the thresher speed and feeding rate. Also, the specific energy is reduced while increasing the thresher rotating speed. The newly designed thresher increased the threshing throughput from 2304 to 2448 kg/h and maximized the efficiency from 98.6 to 99.07% at 1500 rpm rotation speed and 1.8 kg/s feeding rate. Moreover, it reduced the specific energy from 3.37 to 3.15 kW.h/ton for the experimental variables 1100 rpm speed and 1.4 kg/s feeding. The new thresher's lowest damage rate of 0.24% was recorded at a feeding rate of 0.8 kg/s and 1100 rotating speed. These results highlight the distinct effect of the new thresher structure and operating parameters on the rice threshing device's overall effectiveness for medium-sized combine harvesters.