Design and fabrication of an engine operated turmeric grinding machine.

Abstract

Turmeric grinding is one of the most important stages in turmeric processing. In the grinding process, materials are reduced in size by fracturing them, the material is stressed by the action of mechanical moving parts in the grinding machine. Local farmers undertake the grinding process of turmeric by use of manual methods for example grinding stones, mortar and pestle. These methods produce low quality powder that is to say; powder contaminated with dirt, small stones and small wood particles which prove to be dangerous to human health. In addition, the methods are time consuming (farmers spend several hours only to finely grind 0.4kg/hr of dry rhizome manually basing on the physical capability of the person) and tedious (pestle weighs up to 4kg). The automatic machines have a very high initial and maintenance cost. The purpose of this project was to design and construct engine powered turmeric grinding machine for helping turmeric farmers improve on the quality of the ground turmeric powder (free from contamination) which would yield high market prices hence improving their economic wellbeing. Also increase on productivity. The design and construction of an engine powered turmeric grinding machine consisted of determining the appropriate angle of repose for the turmeric rhizome, analysis of forces acting on the machine components to avoid failure during operation. Force analysis led to selection of proper materials to withstand forces. Stainless steels of various grades were the main materials recommended to be used because they are food grade, strong and durable. Engineering drawings of the various components were designed before the grinding machine was constructed and assembled. The turmeric grinding machine was successfully constructed and tested with an efficiency of 98.3% and capacity of 100kg/hr. The machine can be used in production by small, medium and large-scale processors for quick, cheap and hygienic way to grind turmeric to powder due to high grinding efficiency and capacity. Also, the machine is cheap and affordable in terms power requirement, its maximum power requirement is 9HP. however during grinding, some unground particles tend to be kicked out through the feed gate. This is attribute to the type of hopper used. The machine has an NPV of Ushs368,384,867.8 for a period of 3 years. Hence the initial investment of Ushs1,300,000 and a salvage of Ushs 579,670. The cost of the machine is relatively, hence the machine would be welcomed by local farmers and processors.