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

Centrifugal spray dryers are one of the widely used dryers in industrial production. On the surface of the dispersal 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 the feeding rate, as well as on certain physical properties of the material liquid. The liquid is added to the dispersal disc rotating at high speed, and after being thrown into droplets by the centrifugal force, it is dried in the dryer.

Working Principle

The processed liquid after the initial stage is fed into the spray nozzles at the top of the pumping drying chamber. The pressure evenly atomizes the liquid into a 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 flowing into the drying chamber through the hot air ducts. After contacting the mist droplets, the high temperature solidifies and pyrolyzes into the product. The dried finished product, along with the air, passes through a cyclone separator for gas-solid separation, with the finished fine powder recovered. The exhaust gas containing trace amounts of powder is then purified through a bag dust collector, and the exhaust gas meeting environmental protection standards is exhausted through a blower.

System Description

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

2. Feed Material: Liquid material is pumped to the top nozzle by a peristaltic pump.

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 hot air heated and micron droplets atomized by the nozzle.

5. Product Discharge and Dust Removal: Cyclone Separator, Bottom Collection 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 strict filtration equipment, and the liquid channel is rarely blocked by fibrous liquids in the feedstock.

2. Suitable for liquids with higher viscosity (compared to pressure spray drying).

3. Due to the ease of adjusting the nebulizer'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 volume, there is no need to alter the atomizer's operating status; a ±25% variation in feed rate can yield the same product.

5. Due to the centrifugal atomizer, the fog group is primarily on the same horizontal plane, with droplets moving in a composite radial and tangential direction, with almost no initial axial velocity. Therefore, the dryer's diameter is relatively large. With a smaller diameter-to-length ratio, the space within the drying chamber can be utilized more efficiently.