Development and performance evaluation of a guided horizontal conveyor rice harvester
A guided horizontal conveyor rice harvester that uses slider-crank mechanism to drive the cutter bar was designed and constructed. Most Nigerian farms are segregated and this makes it difficult to make use of combine harvester as mechanical means of harvesting. Essential parts of the harvester are cutter bar, conveyor, transmission system and crop reel. The machine constructed was operated and tested on the rice field of National Cereals Research Institute (NCRI), Moor plantation, Ibadan, to evaluate the performance of the machine. A 22 x 3 factorial experimental design with two replicates was used to analysis the effect of engine speed (1200, 1400 and 1800rpm), ecology (irrigated and rainfed-lowland) and moisture content (18.3% and 21.2%) on field capacity, field efficiency, cutting efficiency and operation loss. The test result revealed that moisture content had a significant effect on both the cutting efficiency and operation loss of the machine while the ecology had a significant effect only on the field capacity and field efficiency. At moisture content of 21.2%, the average cutting efficiency was higher with the highest value of 97.2% at 1200rpm. At moisture content of 18.3%, lower operation losses were recorded. The lowest average operation loss of 23.9% was recorded against the 1800rpm. The rainfed-lowland ecology gave a higher field capacity and efficiency. The highest field capacity of 0.0525ha/hr and field efficiency of 49.1% was recorded at 1400rpm. Maximum cutting efficiency of 97.2% was recorded at 1200rpm and 21.2% moisture content, and, lowest operation loss at 1800rpm and 18.3% moisture content.
Keywords: Guided rice harvester, horizontal conveyor, slider-crank, cutter bar