Comparison Of Three Bulk Curing Barn And Baking Performance Of Key Technology Supporting

This paper takes the three different material heat interchangers widely used in Fujian as research objects,which are the metal heat interchanger of HAIDISHENG Bulk Curing Barn,the refractory heat interchanger of LONGYAN Bulk Curing Barn,and the ceramic flue heat interchanger of SANMING Bulk Curing Barn,and carries on comparative analysing the temperature equilibrium,humidity equilibrium,energy consumption and cost of curing and energy efficiency of bulk curing during tobacco leaf curing.Then, the paper studies on the comprehensive techniques for bulk curing,and conducts the experiment of several essential temperature sections during tobacco leaf curing,in the hope of synthetic evaluation the function of bulk curing barn and research into the optimum index of tobacco leaf bulk curing process parameters.From the study of function of bulk curing barn of the three different material heat interchangers,we can find that the function of bulk curing barn of SANMING ceramic flue heat interchanger is good,the barn plane temperature difference is relatively balanced,the barn vertical temperature difference is smaller, and each layer temperature equilibrium is better during tobacco leaf curing; match equalization of thermo-hygrometer and the plane humidity difference is better, the vertical humidity difference is smaller and and each layer humidity equilibrium is better; The heat loss of tail-gas chimney is small.the consumption per kg of dry bituminous coal and power are1.07 kg,0.42kw·h-1 respectively,the comprehensive cost of dry tobacco leaf per kg is 0.97 yuan,the cost of energy consumption relatively high.The energy efficiency of bulk curing barn is high to 52.48%.Because the heat interchanger of bulk curing barn is ceramic flue,the cost of construction is low correspondingly.The function of bulk curing barn of HAIDISHENG metal heat interchanger,the barn vertical temperature difference is smaller and each layer temperature equilibrium is better during tobacco leaf curing; match equalization of thermo-hygrometer is worse, the plane humidity difference is big, equalization is relatively poor; The heat loss of tail-gas chimney is relatively large.the consumption per kg of dry bituminous coal and power are 1.08 kg,0.34kw·h-1 respectively,the comprehensive cost of dry tobacco leaf per kg is 0.93 yuan,the cost of energy consumption relatively low.The energy efficiency of bulk curing barn is high to 51.53%.Because the heat interchanger of bulk curing barn is metal,the cost of construction is high correspondingly.The function of bulk curing barn of LONGYAN refractory heat interchanger,the barn plane temperature difference is relatively balanced,the barn vertical temperature difference is bigger, and each layer temperature equilibrium is worse during tobacco leaf curing; match equalization of thermo-hygrometer and the plane humidity difference is better; The heat loss of tail-gas chimney is small.the consumption per kg of dry bituminous coal and power are 1.00 kg,0.37kw·h-1 respectively,the comprehensive cost of dry tobacco leaf per kg is 0.89 yuan,the cost of energy consumption relatively low.The energy efficiency of bulk curing barn is low to 47.36%.Because the heat interchanger of bulk curing barn is refractory,the cost of construction is low correspondingly.The results of different air velocity test in bulk curing barn were showed as follows. Energy consumption of the air velocity in bulk curing barn during curing process, low speed during yellowing stage, high speed during color fixing stage, low speed during the stem-drying stage was lower than other treatments. The temperatures in the different parts of bulk curing barn of that treatment were more uniform. The single leaf weight, appearance quality, chemical composition and sensory quality of that treatment were all the best.The test of different times at yellowing stage and color fixing stage were showed as follows. The optimal choice for lugs leaf was dry bulb temperature 42℃, wet bulb temperature 38℃, duration time of 12h; dry bulb temperature 54℃, wet bulb temperature 39℃, duration time of 12h. The energy consumption, ratio of high quality leaves, appearance quality, chemical composition and sensory quality of that treatment were all the best. The optimal choice for cutter leaves and upper leaves was dry bulb temperature 42℃, wet bulb temperature 38℃, duration time of 16h; dry bulb temperature 54℃, wet bulb temperature 39℃, duration time of 12h. The energy consumption, ratio of high quality leaves, appearance quality, chemical composition and sensory quality of that treatment were all the best.