Browsing by Author "Trim, D.S."

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    The development of a forced convection solar dryer for red peppers
    (2007) Trim, D.S.; Ko, H.Y.
    The construction of a solar dryer of a double-skin tent design, (the inner skin of black plastic sheet, the outer of clear sheet), with forced air draught provided by an electric fan, is described. The performance of the solar dryer in the drying of capsicum peppers was compared with traditional sun drying; drying times with the solar dryer were reduced by some 65%. The quality of the solar dried peppers was found to be fully acceptable
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    Development of a three stage solar drying system for coffee
    (1986) Trim, D.S.; Brenndorfer, B.
    The traditional practice of sun drying arabica coffee on tables is proving inadequate during the peak processing periods in some cooperative factories in Kenya. A three year programme to develop a solar drying system capable of maintaining a daily throughput of 3t of dried parchment coffee is described. The system consists of three separate stages; initial skin drying, intermediate sun drying on tables - mandatory for Kenyan coffee - and final drying. The skin trying and final drying stages take place in a purpose-designed building which incorporates a solar collector within the roof. Power is provided by a diesel-driven engine directly coupled to an axial-flow fan capable of maintaining an air flow of 8 m's-1. Waste heat from the engine is used to heat the air thereby enabling drying to proceed in all but the worst weather and at night. The solar collector performed well within design specification with a collection efficiency of nearly 50%. In routine operating conditions system-dried coffee equalled that of control batches dried by the traditional method under ideal conditions.