Small low temperature spray dryer is a drying equipment often seen in industry. It is widely used because of its high drying efficiency and good quality of dried products. The quality of spray drying operation has a great impact on the quality of finished products. The process operation procedures must be strictly followed and the operation sequence must be observed.
1、 Preparation before startup
Remove residual dust from the drying room and other systems, clean and sterilize the balance tank, high-pressure pump or milk pump and their input pipelines, and install atomizers.
2、 Start up
1. Close all the doors of the drying tower. Start the intake and exhaust fans, adjust the intake and exhaust air volume to maintain the negative pressure in the drying room at 98-196Pa, and turn on the fluidized bed and other components.
2. Steam supply heating: Slowly open the steam valve to supply steam to the air heater. After the condensed water is drained, close the bypass valve to allow steam to pass through the condenser valve and discharge the condensed water, stabilizing the steam pressure at the required value. After hot air enters the drying room and system, it needs to be maintained at 95 ℃ for 10 minutes for pre sterilization.
3. Feeding spray
Pressure spray: start the high-pressure pump to deliver concentrated emulsion to the nozzle (open the valve in order) to start spray, observe the atomization and adjust it in time.
Centrifugal spray: start the feeding pump, first send water to the centrifugal disk for spray, adjust the flow of the pump, when the inlet and exhaust air temperatures reach normal, formally send milk, observe the atomization accuracy and adjust it in time.
3、 Running operations
1. During operation, it is necessary to maintain stable inlet and exhaust temperatures, stable temperature and concentration of concentrated milk, and good atomization state. Generally, the operation of maintaining stable exhaust temperature and adjusting other aspects is adopted.
2. Strictly implement hygiene regulations to avoid contamination by foreign bacteria.
3. To prevent weaning or other sudden malfunctions such as water, electricity, or other problems, and to avoid quality issues.
4、 Parking
1. Stop the high-pressure pump or milk pump;
2. Close the main steam valve;
3. Stop the exhaust fan;
4. Open the drying room door and sweep the powder.