What are the principles of the spray dryer and the precautions during production?

Spray drying is a method of systematic technology applied to material drying. After the thinner is atomized in the drying room, the water vaporizes quickly in contact with the hot air, and the dry product is obtained. This method can directly dry the solution and emulsion into powder or granular products, which can save the evaporation, crushing and other processes.

Through mechanical action, the material to be dried is dispersed into very fine mist-like particles, which increases the evaporation area of ​​water and accelerates the drying process) and contacts with hot air to remove most of the water in an instant, so that the solid matter in the material Dry to powder.

During the production process of the spray dryer, the speed of the nozzle is too low, the evaporation rate is too low, and there is noise or vibration when the centrifugal nozzle is running. How to deal with it?

The speed of the nozzle is too low, the evaporation is too low, mainly because the centrifugal nozzle part is faulty, so stop using the nozzle and check the internal parts of the nozzle. The reasons may be: the air volume of the whole system is reduced; the inlet temperature of the hot air is low; the equipment has air leakage, and cold air enters the drying room.

The remedial measures are: check whether the speed of the centrifuge is normal; check whether the position of the regulating valve of the spray drying equipment centrifuge is correct; check whether the air filter and air heater pipes are blocked; check whether the grid voltage is normal; check whether the electric heater is working normally; Check whether the connection of each component of the spray drying equipment is sealed.

There is noise or vibration when the centrifugal nozzle is running. It is mainly due to the residual material in the nozzle or the bending and deformation of the main shaft caused by improper cleaning and maintenance of the nozzle of the spray drying equipment. It may also be that the dynamic balance of the centrifugal disk is not good. Solution: Check whether there are residual substances in the spray disc, and if so, clean it in time; if there is any abnormality in the main shaft, replace it and readjust or replace the dynamic balance of the centrifugal disc.



When the spray dryer is in operation, do not touch the rotating parts (atomizer, atomizing disc, belt, motor blade). The surface temperature of the spray dryer is relatively high during the operation of the spray dryer or after a period of time after it has been shut down. Please do not use it. Hand touch bag filter, cyclone separator, air duct, atomizer, exhaust fan, observation window and other components. When the temperature of the drying tower of the spray dryer does not drop to normal temperature, please do not enter the tower. When the oxygen concentration is less than 21%, it is strictly forbidden to open the door of the spray dryer for inspection; otherwise, it is easy to cause the operator to be hypoxic and suffocate.



Every time before opening the spray dryer, the two filling ports of the atomizer must be filled. When turning on the freezer, the circulating water must be turned on; when opening and closing the door of the spray dryer, disassembling and disassembling the air duct, cyclone separator, and atomizer, be careful not to pinch your hands and fingers. During the closed operation of the spray dryer, when spraying organic solvents (such as ethanol, xylene, etc.), the oxygen concentration must be controlled below 5% (by introducing N2 again or restarting the machine, the oxygen concentration can reach the required value), otherwise organic Solvents present a fire and explosion hazard.