Technical and economic evaluation of a modified rice mill (Kato steel huller) for dehulling dry coffee

Date

1993

Abstract

This study assessed the operating characteristics of a modified Kato rice mill adapted for dehulling dry coffee berries. The machine was evaluated to determine the effect of factor variables: huller blade clearance, hopper opening and cylinder speed on the responses: hulling capacity, hulling efficiency, and percentage whole green coffee beans. The Kato steel huller had an average hulling capacity of 120 kg/hr of dry coffee berries, an average hulling efficiency of 98.84 percent, and an average percentage whole green coffee beans of 91.34 percent. It had an average hulling recovery of 53 percent. An increase in hopper opening from 4 cm to 6 cm decreased the hulling efficiency from 99.6 percent to 98.8 percent. An increase in blade clearance from 4mm to 6mm increased the percentage whole green coffee beans from 88.6 percent to 91.8 percent, but reduced the hulling efficiency from 99.8 percent to 96.4 percent. An increase in the angular speed of the rotating cylinder from 600 rpm to 800 rpm increased the hulling capacity from 1.7 kg/min (102 kg/hr) to 2.35 kg/min (141 kg/hr). The Kato steel huller gave an optimum performance at hopper opening of 6 cm, blade clearance of 5 mm and an angular speed of the rotating cylinder of 800 rpm. It had an optimum capacity of 2.4 kg/min (144 kg/hr), hulling efficiency of 98.89 percent, and percentage whole green coffee beans of 93.23 percent. The existing coffee mills had an average payback period of 1.66 years and 1.94 years for Escuata and Jewels, respectively. Escueta had an average break-even point of 31 days per year while Jewels had 34 days per year. The net present value of Escueta and Jewels was P287,067 and P259,382, respectively. The BCR was 1.99 for Escueta and 1.88 for Jewels. Existing kiskisan used for both rice and coffee milling had a payback period of 1.39 years, a break-even point of 25 days, a net present P248,890, and a BCR of 1.71. For a new acquisition of kiskisan to be used for both rice and coffee milling, the payback period is 1.81 years, the break-even point is 38 days, the net present value is P108,117, and the BCR is 1.49. The adaption of kiskisan rice mills for coffee dehulling was technically and economically feasible.

Document Type

Master Thesis

Degree

Master of Science in in Agricultural Engineering

Language

English

LC Subject

Rice, Kato steel huller, Coffee

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 995 1993 A2 P65

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