Paper

A Re-designed Kiln for Ashing Cocoa Pod Husk (CPH) in Cocoa Growing Areas of Ghana


Authors:
P. S. Kwawukume; Albert Essuman; P. S. Kwawukume Jnr
Abstract
A redesigned downdraft kiln for ashing cocoa pod husk in cocoa growing areas of Ghana was calculated using three-layer brick wall structure derived from thermal conductivity calculations yielding outer wall temperature of 85 oC capable of withstanding cyclical heat and cold temperatures without shelter over the structure. All calculations were based on the length of the bricks and their thermal conductivities. Activities on cocoa farms led to tons of leftover cocoa pod husks (CPH) as waste after harvest seasons when nearly all useful products have been extracted and sold to marketing boards. Farmers on their own have attempted to ash the CPH by bonfires but ended up unintentional bushfires, which even destroyed their farms As an improvement in bonfires, up-draft kilns were used but did not serve the purpose entirely due to technical problems in some elements of kiln design parameters that led to low quality of ash from high percentage of unburned husks. The approach used was the prototype design of down-draft kiln with three new features, namely, an dedicated chamber to provide heating fuel in the raining season when only the drying husks are required; an empty chamber in front of the chimney duct which eventually reduces the speed of hot air on escape through the chimney by natural draft principle and maintains a steady temperature in the main combustion chamber; the suspending metal grates with high density bricks which turn into the suspension brick platform. Compared with the unburned lumpy ash from the previous kilns, the re-designed kiln with drying and incinerating chambers produced good ashes throughout the year for industrial use.
Keywords
Cocoa Pod Husk (CPH); Kiln Design; Uniform Heat Distribution; Chimney Wall/ Height; Suspension Grate Design
StartPage
30
EndPage
36
Doi
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