SOYBEAN THRESHING MECHANICS .2. IMPACT

An experimental device was built to study the use of mechanical impact to thresh soybeans from standing plants. The maximum threshing efficiency of the impact device was 92.5%. Threshing efficiency increased significantly with decreasing pod moisture content. The seed damage was within acceptable levels despite an increasing trend with increasing impact speeds and decreasing pod moisture content. The estimated energy absorbed per pod at 10% moisture content (w.b.) was 0.0127 J. The energy used by conventional combines was 20% higher than that required by the impact device, and approximately 30 times higher than the total energy absorbed by pods during shattering.