Design and Production of a Rice Threshing Machine to Enhance Rice Harvesting in Nigeria

The work ‘’Design and Production of a Rice Threshing Machine to Enhance Rice Harvesting in Nigeria’’ has been carried out with the intent of boosting rice production in Nigeria. The work started with structural design of the machine using AutoCAD. This was followed by detail machine parts design, design calculations, materials specification and selection, detail parts production, and assembly. After the assembly process the machine was subjected to performance evaluation and testing, the outcome showed that the research work designed, and produced a rice threshing machine for rice threshing, after rice harvest. The research work evaluated the cost of producing a unit of the machine and put the cost at ₦450,000 ($331.6), while the performance evaluation cost was put at ₦100,000 ($73.69). The study evaluated the performance of the produced rice threshing machine and measured parameters such as stripping efficiency, threshing efficiency, cleaning efficiency, total weight of chaff, separation efficiency, grain losses and threshing throughput capacity. The study carried out DOE and analysis of data. The research study revealed that the stripping efficiency of the rice threshing machine was 3.23%, the threshing efficiency was 80.72%, the cleaning efficiency was 85.72%, and the separation efficiency was 81.11%. The research work showed that grain losses were as follows: drum losses 19.28%, cleaning losses 4.42%, and separation 6.16%. The study showed that the weight of grain produced decreased with increased efficiency. The study developed model equations for cleaning efficiency, separation efficiency, cleaning losses, separation losses and total grain loss. The study observed that the throughput capacity of the rice thresher was significantly affected by the threshing time. The ANOVA results showed that the model for the throughput capacity was highly significant (P = 0.0000) with an exceptionally high R2 value of 99.92%. This indicates an excellent model fit. Threshing time was found to be extremely significant (P= 0.0000), whereas moisture content was not significant (P = 0.375). This confirms that throughput capacity is primarily determined by the rate at which the machine processes material over time.