Application Research Of Far-infrared Carbon Fiber Electric Heating Technology In Tobacco Bulk Curing

In present, bulk curing barn is more and more widespread because of its own advantages. But the bulk curing barn, which fueled with coal was limited by some troubles, such as Low heat utilization rate, high energy consumption, etc.. To the contrary, bulk curing barn heated by Far Infrared Carbon Fiber Electric Heating Machine FICFE was of highly accurate in controlling the temperature and humidity, easy for operation and no harmful gas emission etc. To some extent, bulk curing barn heated by the FICFE just can make up for the coal. The current thesis was attention to the intensive application of FICFE technology in the bulk curing barn, aiming to provide a reference for the further development of bulk curing barn technology. The main results were showed as follows:1. In the bulk curing barn heated by FICFE, the temperature difference, regardless of the same layers or different layers were much lower than those in bulk curing barn fueled with coal during the yellowing stage, color fixing stage and Stem-drying stage. In detail, the temperature difference in same layers ranged0to0.60C when the temperature stable, which was1℃lower than the bulk curing barn with fuel. The maximum temperature difference was1℃during the temperature rise period0C, which was20C lower than the bulk curing barn with fuel. the temperature difference in different layers ranged0to1℃at temperature period and maximum with2.40C at temperature rise period, which was0.50C and0.60C lower the latter, respectively. The heating rate in bulk curing barn heated by FICFE was2-3times faster than that in bulk curing barn fueled with coal. To the contrary, the temperature difference between the two temperature sensors in the FICFE barn was1-1.50C lower than the latter. For the bulk curing barn heated by FICFE, it had no use for to open the barn door that can maintain the enough heat quantity to launch the generators for continue flue-curing, so it was be favorable to prevent tobacco altering for the worse. The bulk curing barn, not only the FICFE mode, but also coal-fueled mode, can match the set temperature and humidity. In another word, the bulk curing barn with two heating mode could meet the needs of tobacco flue-curing.2. The changes of temperature and humidity in the two heating mode bulk curing barn were similar during different flue-curing stages, so did the transition metabolism of carbohydrates and nitrogenous compounds. The rates of water loss and dry matter content change were almost similar between the two heating mode of bulk curing barn during the early of yellowing stage and the stem drying stage. By contrast, the rates of water loss and dry matter content change in FICFE mode bulk curing barn were faster than in coal mode by5%during the later of yellowing stage and the whole color fixing stage. In further, the single weight of tobacco leaves in FICFE mode bulk curing barn was Greater than that of coal-fueled mode, so did the Stem ratio of tobacco leaves.3. Comparing the FICFE mode and the coal-fueled mode bulk curing barn, the Accuracy in controlling temperature and humidity of the FICFE mode was2-3times to that coal-fueled mode. The total cost of FICFE mode at the whole fuel-curing period was lower than the coal-fueled mode by2000yuan. The cost of energy and labor per kilogram dry tobacco leaves in FICFE mode was lower by0.4yuan. For the quality of tobacco, the FICFE mode could evidence elevated the presentation quality of tobacco leaves, increase the average price of tobacco leaves by0.35yuan, and raise the rate of superior tobacco by6.11%. In a word, the FICFE mode bulk curing barn could ensure the improving quality of tobacco leaves.4. For three humidity treatments (low humidity, medium humidity and high humidity) during tobacco fuel-curing, a much more stable and highest grade in presentation quality presented in medium humidity treatment. There were a obvious advance for aroma concentration in medium humidity treatment, but no significant difference in tobacco aroma concentration were showed in the three treatment. The application of bulk stacking fuel-curing could effectively elevate the presentation quality grade of flue-cured tobacco leaves, it also could make more enough aroma concentration and taste good. A relative higher humidity fuel-curing was propitious to raise the total aroma concentration in fuel-cured tobacco leaves.