Study On The Technology Of Bulk Curing In Flue Cured Tobacco

Intensive curing, the need to adapt to the development of modern tobacco agricultural production, is not only the inevitable demand for small-scale planting changed to specialization and farming, but also one of the important ways to reduce the heavy workload of farmers to grow tobacco, which, owing the advantages of large energy of curing, low curing cost, low labor intensity, etc. will affect China’s reform of tobacco production and have the prospect of broad application. About it, there are3kinds of new curing skills, that is, cutting the stem before curing, curing with waste heat and cased intensive curing, which have different impacts on tobacco. The summarized effects are as follows:1The skill of cutting the stem before curing can significantly reduce the amount of smoke with a rate of12%-13%, which is proportional to the stem’s length, the same to the condition of tobacco leaves’freshness and dryness. This skill can shorten the time for drying, consequently reducing the time of curing process more than16hours, which is contrary to the skill of cased intensive curing.2About cutting the stem before curing, there is a tendency of decreasing the temperature in leaves’dryness, about3degrees compared with conventional control; or curing with waste heat can meet the demand of tobacco curing after48hours, whose exhaust air in conducive to yellow the leaves and improve its qualities; or the cased intensive curing, basically the same humiture with the traditional hang-pole curing during the early curing and then lengthening the period of color-setting and dryness, is slow in the process.3The2skills of cutting the stem before curing and curing with waste heat, to some extent, can reduce energy consumption, improve tobacco’s quality, increase the proportion of middle-and high-level leaves, raise the average price of leaves and the income of farmers. While cased intensive curing apparently can save labors, but increase the energy consumption of dry tobacco per kilo, easy to produce black-tank tobacco and wet-stem tobacco and decrease in the ratio of middle-and high-level tobacco and the average price.4In general, these3skills are coordinated and appropriate in chemical composition of tobacco leaves; however, cutting the stem before curing is not conducive to degrade the starch, contrary to the latter two skills with comparatively decreased starch content. For cutting the stem before curing, it is not easy to control the yellowing-temperature and with low water content, not suitable to consume and degrade starch. While curing with waste heat, it would release the humiture in the last yellowing stage and keep the dry-bulb temperature between32and40degrees and wet-bulb between31.5and36degrees in the curing room which is conducive to amylase activity and accelerate decomposition and consumption; about cased intensive curing would make tobacco’s composition coordinated through lengthened curing time to consume the starch in tobacco leaves.5Nevertheless, the existed curing skills obviously cannot meet the technology of cased intensive curing, which should keep finding and solving the problems from technology and endeavor to innovate and further improve. And it is found that the bottom height of box cart is short, easy to make poor air flow in one side of door and lead to improper humiture distribution, which is not favorable to improve the quality of tobacco leaves.