The possible problems in the production of lab spray dryer and their causes and remedial measures are summarized as follows for reference during operation.
1 Severe wall sticking phenomenon is mainly manifested by sticky wet powder everywhere in the lab spray dryer room. The reasons are:
(1) The feed volume is too large to fully evaporate;
(2) The drying chamber is not heated enough before spraying starts;
(3) When spraying starts, the feed flow rate is adjusted too large;
(4) The lab spray dryer feed liquid is not enough stable. In view of the different causes of the above-mentioned problems, the following measures can be taken in sequence: Appropriately reduce the amount of feed; appropriately increase the inlet and outlet temperature of the hot air; when starting to spray, the flow rate should be small, gradually increase, and adjust to the appropriate time; check the pipeline Whether it is blocked, adjust the solid content of the material to ensure the fluidity of the material and liquid.
2 Product moisture content in lab spray dryer experiment is too high. The exhaust temperature is the main factor affecting the moisture content of the finished product. Therefore, the reason for the high moisture content of the product is generally that the exhaust temperature is too low. The exhaust air temperature can be adjusted by the amount of feed. Therefore, the corresponding measure is to appropriately reduce the feed volume to increase the exhaust air temperature.
3 The product purity is low, and the possible reasons for this situation caused by excessive impurities are as follows:
(1) The air filtration effect is not good;
(2) The dust is mixed into the finished product;
(3) The purity of the raw material is not high;
(4) The lab spray dryer equipment incomplete cleaning. The remedial measures that can be adopted are: Check whether the filter material in the air filter is evenly laid, whether the filter has been used for too long, if it should be replaced immediately; Check the coke powder at the hot air inlet to overcome the turbulence; The material liquid should be filtered before spraying ; Re-clean lab spray dryer equipment.
5 The phenomenon of powder tail dust is serious, the product yield is low, and the loss of powder tail dust is too much, which greatly affects the yield of the finished product. The general reason is that the lab spray dryer separation effect of the cyclone separator is poor. If this happens, check whether the cyclone separator is deformed due to knocks or collisions; improve the air tightness of the inlet and outlet of the cyclone separator, and check whether the inner wall and the discharge port are blocked by material accumulation. Of course, the lab spray dryer separation efficiency is also related to the specific gravity and particle size of the powder. For some materials, a second-stage dust removal can be added as needed.
6 The low speed of the centrifugal lab spray dryer nozzle is mainly due to the malfunction of the centrifugal nozzle components, so stop using the nozzle and check the internal components of the nozzle.
7 The reasons for the low evaporation rate may be:
(1) The air volume of the entire lab spray dryer system is reduced;
(2) The inlet temperature of the hot air is low;
(3) The labv spray dryer equipment has air leakage and cold air enters the drying room.
The remedial measures are:
(1) Check whether the speed of the centrifuge is normal;
(2) Check whether the position of the centrifuge regulating valve is correct;
(3) Check whether the air filter and air heater pipes are blocked;
(4) Check whether the grid voltage is normal
(5) Check whether the electric heater is working normally;
(6) Check whether the connection of each component of the lab spray dryer equipment is sealed.
8 Noise or vibration during the operation of the centrifugal lab spray dryer nozzle is mainly due to the residual material in the nozzle or the bending and deformation of the spindle caused by improper cleaning and maintenance of the nozzle. It may also be caused by the poor dynamic balance of the centrifugal disk. Solution: Check if there is any residual substance in the spray plate, if there is any, clean it in time; if the spindle is found to be abnormal, replace it; re-adjust or replace the dynamic balance of the centrifugal plate.