High speed centrifugal spray dryer is one of the most popular equipment in drying equipment. It is suitable for special drying methods of emulsification, suspension, paste, liquid and other equipment. The centrifugal spray dryer has ideal effect and high efficiency. The size of the dust particles does not need to increase the grinding process. At present, high-speed centrifugal spray dryer is widely used in chemical industry, light industry, food industry and so on.
Observing the production process of centrifugal spray dryer, it is easy to see the crux of the problem of energy consumption. From the source, we can gradually solve the problem of optimization so as to fundamentally solve the problem, such as using heat exchangers to contact the tail gas with higher temperature and the low temperature air intake, so as to increase the intake temperature. This can make full use of the heat in the tail gas, thus reducing the use of heat transfer oil and reducing the production cost. This is also one of the feasible ways.
Here are three ways to save energy and reduce consumption for spray dryer.
1. Increase the inlet temperature of hot air:
Under the condition of constant temperature at the outlet of the spray dryer, the higher the inlet temperature of the hot air is, the higher the total heat will be brought into the unit. The more the heat of the unit mass passes to the droplet, the more water evaporated by the unit hot air. When the production capacity of the spray dryer is constant, the required hot air volume is reduced (that is, the heat taken away from the tower when the hot air is removed), which reduces the heat consumption of the centrifugal spray drying mechanism powder, and improves the utilization ratio and the thermal efficiency of the hot air. However, the temperature of hot air entering the tower should not be too high (no more than 600 ℃), if the temperature is too high, the top air distributor will be burned out.
2. Reduce the temperature of hot air out of the tower:
Under the condition of certain hot air temperature in the inlet of the spray dryer, the lower the temperature of the hot air tower, the greater the temperature difference between the inlet and outlet. The greater the heat transferred to the mud for drying, the higher the utilization rate of hot air. However, the exhaust temperature should not be too low. When the temperature is lower than 75 ℃, it will affect the normal drying because the powder is too wet.
3. Recycling of hot air (waste gas) out of Tower:
After the spray dryer is pulverizing, if the hot air from the tower is directly discharged into the atmosphere, this part of the heat loss will be very considerable (about 10% to 20% of the energy consumption of the pulverizing process). Therefore, this part of the waste heat should be fully utilized. For example, the hot air from the tower can be recycled to the preheating and drying process. In addition to the direct recycling of the hot air from the tower, the heat exchanger can also be used to store or exchange this part of the waste heat for reuse.