Development And Performance Evaluation Of Rice Destoning Machine

This implies that a single belt of the above standard and specification is sufficient for transmitting the power.
3.4    Material Selection
The particular conditions under which the various parts of the de-stoning machine are subjected to, makes it necessary to select adequate materials for the fabrication based on functionality, durability, ability to withstand vibration and the cost of such materials. In choice of material, their physical properties of metals and behavior are considered such that when subjected to the machine, running condition should be able to withstand the service condition.
In this design, the strength of the materials, serviceability of parts and availability were put into consideration.(Olugboji and Jiya,2014)
3.5    Fabrication Procedure and Assembly
Machine frame
The de-stoner machine frame carries every other component of the machine. It is made from mild steel angle iron of 38mm×38mm×5mm thickness. The lengths of the angle iron were cut to the required sizes with a hacksaw after appropriately measuring and marking out the length of each stands. The top and bottom bracings were also measured, marked out with the scriber and cut with the grinding disc ensuring that they were neatly cut out for ease welding, an engineering square was used to enhance perpendicular and straight cut.
Furthermore, the prime mover seat was measured and slotting mount measured and marked out with a sharp scriber. The prime mover seat angle iron cut was then taken to the drilling machine; the drilled point was cut into dimension. The frame materials are then brought to the welding machine and carefully assembled with a few tacks to hold the materials together, when an assurance is made as to the designed position and orientation of the assembled machine frame part, then full weld of the parts is done.
Upper vibrating sieves
The machine has two mechanically agitated sieves. It was constructed from 2mm thick galvanized metal sheet. The length, breadth, and height known to be 390mm×380mm×200mm were measured and mark out with a sharp scriber. This was cut with a grounding disc and fold to design shape on an anvil. The folded vibrating sieve is then welded with 8 bearings to the frame. An eccentric shaft was welded at the center of the vibrating sieve to the machine frame to enhance the oscillatory movement of the vibrating sieve.