Dried turmeric rhizomes are generally polished to remove the outer dirty skins, roots and soil, and to transform them to relatively smooth, bright and yellowish rhizomes. In farm level, turmeric polishing is carried out manually following conventional methods, which are slow, tedious and labor-intensive operation. To overcome these problems, a medium-size turmeric polisher was designed and fabricated in Farm Machinery and Postharvest Process Engineering (FMPE) Division of Bangladesh Agricultural Research Institute (BARI) during 2013–14. Length, width and height of the polisher were 1040 mm, 850 mm and 1450 mm, respectively. Weight of the turmeric polisher was 90 kg. A 0.37-kW single-phase induction-type electric motor was used as the source of power for operating the polisher. The polisher was tested in FMPE Division, Regional Spices Research Station (RSRS), Magura and Hill Agricultural Research Station (HARS), Khagrachari. The polisher took 25 minutes to polish a batch of 30 kg dried turmeric. The price of the polisher was Tk 30000. The average cost of polishing by the polisher was Tk 1.42 per kilogram turmeric against the hand beating polishing cost of Tk 5.12 per kilogram. The polisher can save 81% time and 78% cost of polishing than that of hand beating method. Payback period of the polisher is 97 hours. Therefore, the polisher can be recommended for turmeric polishing in Bangladesh as well as for other turmeric growing countries.J. Bangladesh Agril. Univ. 16(2): 303-308, August 2018
Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics
