- May 08, 2018 -
1) Increase the inlet temperature and reduce the outlet temperature
Increasing inlet temperature can reduce heat consumption (constant production capacity). Heat consumption of desiccator is usually expressed as heat consumption (the amount of heat needed to evaporate 1kg water and sometimes the heat required per kg product).
2) Increase the solid content of the material and liquid
Spray drying process is an expensive method for evaporation and volatiles. Therefore, to obtain the best condition of heat utilization, it is always to improve the liquid solid content to the maximum value as far as possible.
3) Increase the temperature of the material
Increasing the feed liquid temperature (using waste heat preheating or indirect steam heating) can reduce heat consumption per unit dry product. The preheating of the liquid can reduce the viscosity of the liquid and improve the atomization, prevent the crystallization of the liquid and block the atomizer. When the temperature of the material is high, the droplet can be evaporated directly in the dryer, and there is no preheating stage.
4) partial recirculation of the exhaust air
In the open cycle process, exhaust air is discharged into the atmosphere, which can lose about 10%-40% of total heat. Especially when the temperature of the dry air outlet is particularly high, the heat loss is greater.
If the outlet temperature exceeds 120℃, the use of partial exhaust air recycling technology can save up to 20% fuel.
5) Recovery of waste heat by heat exchanger
Using heat exchanger to recover heat from exhaust air can significantly save energy. There are two types of heat exchangers, namely air-air and air-liquid-air, which can be used.
6) two or three-grade drying
Two - or three - stage drying has the following characteristics:
a. In the last stage of drying, the product can achieve lower moisture content.
b. Lower product temperature can be obtained.
c.Particle size distribution can be changed by grading or agglomerate.
d.To improve the thermal efficiency of the drying process.