An Overview of the Principle and System Composition of Centrifugal Spray Drying Equipment

Centrifugal spray drying equipment is one of the most widely used dryers in industrial production. On the surface of the dispersing disc, the liquid spreads out as a thin film and is ejected at high speed around the circumference. The atomization effect depends on the circumferential line speed and feeding rate, as well as certain physical properties of the liquid. The liquid is added to the dispersing disc rotating at high speed, and then dried in the dryer after being thrown into droplets by the centrifugal force.

Operation Principle

After the initial process, the liquid material is pumped into the spray nozzle at the top of the drying chamber. The air pressure atomizes the liquid into a fine mist of micrometer-sized droplets, which then enter the drying chamber. Atmospheric air enters the heating system and is heated to the required temperature, uniformly distributed through the hot air ducts into the drying chamber, where it contacts the mist droplets, causing them to solidify at high temperatures and pyrolyze into the final product. The dried product, along with the air, passes through a cyclone separator for gas-solid separation, with the fine product powder recovered. The exhaust gas containing trace amounts of powder is then passed through a bag filter for further purification, and the exhaust gas meeting environmental standards is exhausted through a blower.

System Description

1. Heating: Composed of electric heaters and ceramic electric heating wires, it provides the high-temperature air required for the atmospheric air heating process.

2. Material Inflow: The liquid material is pumped through a peristaltic pump to the top nozzle.

3. Spray: The liquid material is atomized into micron-sized droplets by the nozzle and then enters the drying tower.

4. Drying: The sample is instantly dried by the combination of heated air and micron-sized droplets atomized by the nozzle.

5. Product Discharge and Dust Removal: Cyclone Separator, Bottom Collector Bottle.

The characteristics of centrifugal spray drying equipment are primarily determined by the features of the atomizer.

The centrifugal spray drying process does not require stringent filtration equipment, and the liquid channel is rarely clogged if there are no fibrous liquids in the feed solution.

2. Suitable for higher viscosity fluids (compared to pressure atomized spray drying).

3. Due to the ease of adjusting the atomizer's speed, it is relatively simple to control the particle size of the product, with a narrower particle size distribution.

4. During the adjustment of processing capacity, there is no need to alter the atomizer's operational state; achieving the same product quality is possible with feed rate variations of ±25%.

5. Due to the mist groups generated by the centrifugal atomizer being predominantly on the same horizontal plane, the droplets move in a combined radial and tangential direction, with almost no initial axial velocity. Therefore, the diameter of the dryer is relatively large. With a smaller ratio of diameter to length, the space within the drying chamber can be utilized efficiently.