Thermal efficiency improvement and technology transfer of chimney stove for producing stove; Amphoe Bo Kluea, Nan Province

Salt production by evaporation of brine drawn from deep wells in of Bo Kluea District, Nan, has been carried out for many centuries by using traditional wood-based stoves. This study aims to improve thermal efficiency of traditional stoves, while tradition stove structures and salt making methods were maintained. The prototype and tradition stove were compared by thermal efficiency method. The tradition stove was constructed with clay. The prototype chimney stoves have been making from brick plastered with cement. The prototype chimney stove was insulated by filling rich hush in the gap of stove wall which has 3 cm. thicknesses and the end of the chimney. The stove can put 2 pans. Eucalyptus woods were used be fuel for testing the thermal efficiency. The prototype stove increases thermal efficiency approximately by 5.3 percents form normally 9.6 percents. This is achieved by using carbonized rice husk as stove insulating materials to reduce heat loss through stove walls. Salt production cycles are decreased by 25 minutes from 4.5 - 5 hours and the rate of fuel per day decreased 14 - 15 kilograms from 257 kg of firewood. Costs to improve salt production stoves 1,545 THB have a Pay-back period 107 days. The improved prototype chimney stove can help to decrease fuel costs and increase the salt production rate. This research is not only saving energy but also keep tradition of local living.