Design, Finite Element Analysis, and Development of a Portable Electric Yam (Dioscorea alata) Grating Machine for Small-Scale Agro-Processing Applications

Introduction:
The manual grating of yams is still labor intensive, time consuming and inefficient for domestic and small scale agro-processing especially in rural and resource limited settings. The present study is engineering development of a portable electric yam (Dioscorea alata) grating machine to increase processing efficiency, avoid labour intensive and increase food production productivity by mechanization.
Methods:
The machine was designed in Autodesk Inventor 2019 and structurally analyzed with Ansys Static Structural finite element analysis (FEA). The key design parameters were determined and they include hopper volume (4.177 x 10-3 m3), hopper capacity (3.717 kg), drum torque (12.88 Nm), minimum diameter of the shaft (3.86 mm), selected power rating (1.447 hp) and bearing selection (No. 206, C = 12.35 kN). The system was made of food-grade stainless steel and subjected to load testing conditions to determine its viability in operation. Fabrication cost and practical viability was also evaluated by performing a techno-economic analysis.
Results:
FEA results revealed a maximum Von Mises stress of 3.289 MPa and max total deformation of 3.391 × 10–3 mm, both of which are excellent and suggest a safety factor of about 76 for the material yield strength. Experimental testing verified the stable operation under working loads conditions with no structural failures and less vibration. The total fabrication cost was estimated at ₦144,050 (around USD 90) which is very expensive for small-scale adoption.
Conclusion:
The developed yam grating machine has the characteristics of structural reliability, high efficiency and economy. It is compact, made of stainless steel, it has direct motor coupling and is also low cost, which makes it a suitable mechanized solution for small-scale agro-processing. The study shows the development of sustainable food processing equipment by using mechanical design, simulation and economic evaluation successfully.