COMPARATIVE STUDY OF POT SKIRTS WITH DIFFERENT INSULATION THICKNESSES

Abstract

One of the major losses of heat from cooking stoves is through the body of the pot, which is exposed to the surrounding air. Design and fabrication of pot skirts was undertaken in this work to minimize the heat losses. The design improvement of the stove focused on the provision of insulation with different thicknesses of the skirt body to reduce conduction heat loss to the environment. In the study five pot skirts with insulation thicknesses of 0, 1, 2, 3 and 4 cm were made. For comparison, conventional charcoal stove was also used with no pot skirt. Three parameters (time of initiation of cooking or time to initially reach 75oC, maximum temperature reached during the cooking process and effective cooking time or the time range over which the food temperature was ≥ 75oC) were used for comparison. The comparisons were made using one-way ANOVA followed by pair comparisons whenever the ANOVA result showed significant differences. Skirt body and smoke outlet temperatures were also additional tests made. The plots of the two temperatures were integrated (using MATLAB software) to estimate relative heat losses from the body and the smoke outlets of the stoves. ANOVA and pair comparisons tests showed significant differences (at p = 0.05 level) between conventional and stoves with pot skirts of 2, 3 and 4 cm in terms of early initiation of cooking time. The stove with pot skirt of 4 cm exhibited the earliest initiation of cooking of 6 minutes and the maximum effective cooking time of 57 minutes and hence it was better than the rest. In terms of maximum temperature attained, Both pot with skirt 1 cm and 2 cm are different from the conventional stove. The maximum temperature seems to be negatively correlated with insulation thickness. In terms of effective cooking time, the one with skirt thickness of 4 cm showed significant differences from 1 and 2 cm skirts and the conventional stove. The effect of pot skirt insulation on food temperature is slightly subdued. Skirt insulations of 2 – 4 cm tend to reduce both skirt body temperatures, especially after maximum temperature is reached.