| Our country is the world’s largest tobacco grower, the flue-cured tobacco is one of the largest tobacco cultivated area type。 In2006, our country flue-cured tobacco planting area is1.215million hm2, account for more than80%of the national tobacco area, while the average dry tobacco production is1800kg-1950kg per hectare. In the flue-cured tobacco process,we need to remove more than90%of the moisture in fresh tobacco leaves which have the moisture content of85%-85%, tobacco leaf baking is to spend a lot of energy. We need to consume2.0-3.0kg coal for1.0kg dry tobacco.Therefore, in the process of tobacco leaf baking, implement energy-saving optimization has the great potential.Tobacco planting amount is so big that in the baking process, we will inevitably consume more energy, therefore, energy conservation becomes more important. Current the way of tobacco leaf baking is similar to that of convection drying process, using hot air to give energy to tobacco leaf by leaf tobacco surface makes its internal moisture evaporate, and through the air flow out of the evaporation of moisture. In the process, energy dissipation is mainly wet and heat dissipation, exhaust heat dissipation loss, incomplete combustion of fuel, and maintenance of the structure heat losses, etc. Row of damp heat dissipation includes most of the effective heat dissipation and invalid row of damp heat loss, this part of occupies the30%to50%of the total dissipation energy, as is often the case, the heat is not treated directly and discharged into the atmosphere, caused great waste of energy.In the tobacco leaf baking process, tobacco leaf will undertake a series of physiological and biochemical process, various organic matter is decomposed into a small molecular compound, the small molecular compound is the root of fragrance of tobacco leaf, In the process of dehumidification of tobacco leaf baking, not only to pack a lot of heat out of the smoke chamber, and tobacco leaf decomposition of organic material will be out of the outdoor, which reduces the degree of the aroma of tobacco leaves after baking. From the above, in the current bulk curing barn process, because of the existence of dehumidification process, it can greatly increase the energy consumption in the process of baking, and can reduce the content of aroma substance of install smoke indoor chamber, causing baking dry tobacco defects, such as cost increase, the scent of the leaves is not enough. It is necessary to study a new method of dehumidification to solve the problem radically. Aiming at this defect, this paper proposes a new intensive way of dehumidification-all closed-cycle moisture removal way, using the finned tube heat exchanger,cooling dehumidification methods to remove moisture, from the source to eliminate contact between the intensive curing barn and outside, thereby avoiding energy waste and tobacco aroma substances not enough caused by the defects in the process of dehumidification.Conclusion from this article:when finned tube heat exchanger is used for dehumidification, the wind’s dry bulb temperature, relative humidity and wind speed have great influence on state parameters of hot wet air after the dehumidification. Under the dry bulb temperature and relative humidity certain circumstances, the greater wind speed, the dry bulb temperature of hot wet air will be higher, the higher the moisture content, moisture absorption coefficient is smaller, and dehumidification effect is bad, on the contrary, the dehumidifying effect is better; Under the wind speed certain circumstances, the dry bulb temperature and relative humidity is higher, after dehumidified, hot wet air’s difference of moisture content is higher, dehumidification is more, moisture absorption coefficient is larger. |
PDF Full Text Request