In the drying process of the dryer machine , the thermal efficiency varies greatly. The thermal efficiency is about 20% -50% in the general chemical industry. The main measures to improve the thermal efficiency of the dryer during the drying process are as follows:
(1) to enhance thermal management of the existing dryer, such as to prevent leakage of the drying medium to realize the full combustion in the combustion furnace; as for the dryers with hot air circulating, they should maintain the maximum amount of circulating air as much as possible.
(2) to improve the insulation of the equipment. The heat loss of the general dryers is 3% -30%. Based on the measured amount of heat of the dryer, taking measures to improve the equipment insulation to reduce heat loss.
(3) to prevent the excessive drying of the product. In the drying process, the water content of the product should be strictly controlled within the required amount to avoid excessive drying of the product and the increase of the energy consumption.
(4) to reduce the initial moisture content of the dried material. If the material to be dried is the solution. The film evaporator is available to concentrate it and then conduct the spray drying; if the material to be dried is the suspension, it can be dried after most of the water is removed by filtration, which can reduce thermal energy consumption of the per unit mass.
(5) to recover the heat taken by the exhaust gas. If the inlet temperature of the convection dryer is not too high , the ration of the heat taken away by the exhaust way and the total heat is great and sometimes it can be up to 40% of the total heat. To adopt the heat exchanger to recycle the hat taken by the exhaust gas has been carried out in the industry.
