cause

1. Wall sticking problem

Material properties: Traditional Chinese medicine decoctions have complex ingredients and contain substances such as sugars and proteins that are prone to sticking to the walls.

Equipment factors: blockage of the spray gun nozzle or wear of the spray blade, resulting in poor atomization of the liquid slurry; The sealing at the tower door and spray gun mouth is not tight, resulting in cold air entering the tower body and causing a local temperature drop; Leakage of air in the flip plate feeder at the bottom cone of the tower.

Operational factors: The inlet air temperature is too low, which prevents the atomized liquid slurry from drying quickly inside the tower; Excessive feed concentration and speed result in insufficient drying; The design of the drying tower is unreasonable, such as improper positioning of the atomizer or uneven distribution of airflow inside the tower.

2. Agglomeration problem

　　Chinese medicine spray dryerMainly due to the material sticking to the tower wall staying on the tower wall for a long time, it becomes hard and clumped when baked by hot air.

3. Coking problem

Usually, it is due to the local high temperature of the tower wall, which causes the material sticking to the wall to soften, melt, or even coke.

prevention

1. Wall sticking prevention

Adjust material properties: reduce viscosity by adding drying aids (such as maltodextrin) and adjust pH to reduce wall sticking.

Optimization of equipment design: spray drying equipment with reasonable design shall be selected for correct installation and commissioning. For example, drying tower with vertical cylinder structure shall be selected to ensure correct position of atomizer and uniform airflow distribution. Use anti stick wall coating or regularly clean the tower wall.

Control operating parameters: Dilute the material appropriately to reduce concentration, adjust the feeding speed according to the drying capacity, and avoid being too fast. Properly increase the inlet air temperature to ensure rapid drying of mist droplets.

Using auxiliary equipment: Install a row of nozzles near the tower wall to form an air broom, allowing it to rotate slowly and uniformly on the tower wall, thereby peeling off the material adhered to the tower wall. Use vibration devices or air sweepers to reduce the residence time of materials on the wall.

2. Prevention of clumping

The key is to prevent wall sticking problems. Once the wall sticking problem is solved, the agglomeration problem will also be reduced accordingly.

3. Coking prevention

Ensure effective cooling device: The tower wall is equipped with a jacket cold air cooling device to ensure that the liquid material will not soften, melt or even coke due to local high temperature.

Adjust the tower structure: increase the taper and install an air vibrator on the cone. Use a compressed air vibrator to shake the cylinder and smoothly shoot down the powder adsorbed on the cylinder.

Optimize operating conditions: Avoid prolonged high-temperature operations and ensure that the hot air temperature is moderate, which not only ensures drying efficiency but also avoids material coking.

　　Chinese medicine spray dryerThe causes of wall sticking, agglomeration, and coking problems involve multiple aspects such as material properties, equipment design, and operating parameters. To effectively prevent these problems, it is necessary to approach from multiple perspectives, comprehensively consider and take targeted measures.