Performance of modified thresher for mustard

Effect of feed rate (F) and peripheral speed (PS) on threshing efficiency, cleaning efficiency, grain damage, losses from various outlets of a modified spike tooth cylinder type multicrop thresher was studied. Cylinder concave clearance was kept 25 mm. Number of spikes used was 12 (two/row in helical pattern) instead of 36 spikes used in wheat thresher. Three feed rates of 4.3, 5.0 & 5.8 q/h and four peripheral speeds 13.4, 16.4, 17.5 & 20.1 m/s were selected. The straw grain ratio was 4.02. Threshing efficiency was more than 99.5 per cent and statistically comparable for the studied range of feed rates and peripheral speeds. Cleaning efficiency varied from 97.62 to 99.26 per cent. Cleaning efficiencies were slightly lower at lower peripheral speeds and higher feed-rates. However these were statistically comparable for all the treatment combinations. Grain breakage varied from 0.2 to 0.3% for different feed rates and peripheral speeds except for peripheral speed PS4 (0.79). Per cent broken grains were minimum for treatment combination F2PSI and these were statistically comparable with F3PS1. Total non-collectable losses varied from 0.04 to 0.11 per cent for different feed rates and peripheral speeds of threshing cylinder except for PS4. Percent non collectable losses were statistically comparable for all peripheral speeds except PS4. These were statistically lower for federates F2 and F3 as compared to Fl. Therefore thresher can be operated at peripheral speed PS1 (13.4 m/s) at feed-rates F2 (5.0 q/h) and F3 (5.8 q/h).