In the production of polyaluminum chloride, liquid polyaluminum chloride is generally obtained first, and then the liquid product is dried to obtain a solid polyaluminum chloride product. There are also various drying methods derived. Spray drying polyaluminium chloride is the most common high performance PAC chemical on the market.
Production Process of Spray Drying Polyaluminium Chloride
Spray drying is a drying method that uses an atomizer to disperse the raw material liquid into droplets, and use hot air (air, nitrogen or superheated steam) to dry the droplets to obtain a product. The carburetor component part that disperses the material liquid into droplets is a key component of spray drying, and its function is to disperse the material liquid into droplets. At present, there are three commonly used atomization forms for spray drying.
Airflow nozzle atomization.This method uses compressed air or steam to spray out from the nozzle at a high speed, and disperses the material liquid into droplets by means of the friction force generated by the relative velocity of the air and the material liquid. The air-flow atomizer can atomize high-viscosity materials, and the processing is simpler. However, the efficiency of its compressed air conversion function is very low, so the specific energy consumption of its atomization is large, and the atomization particle size distribution is uneven.
Pressure nozzle atomization.This method is a device that pressurizes the solution through a high-pressure pump and releases the pressure in the small hole to zeroize it. It is characterized by low specific energy consumption.
Centrifugal nozzle atomization.The material liquid is thrown out from the edge of the disc by centrifugal force in the high-speed turntable and atomized. The rotating speed of the turntable is inversely proportional to the diameter of the droplets, and when the rotating speed increases, the spray distance of the droplets is shortened, and the droplet distribution tends to be uniform. Thereby, the diameter of the dry explosion tower can be reduced, the heating degree of the processed materials can be reduced, and the common phenomenon of wall sticking can be eliminated.
Advantages of Spray Drying Polyaluminium Chloride
- The surface area of the droplet group is large and the drying time is short.
- Suitable for heat-sensitive materials. In the high-temperature air flow, the temperature of the surface wetting material does not exceed the wet bulb temperature of the drying medium. Due to the rapid drying, the temperature of the final product is not high.
- Flexible operation, which can meet the quality index requirements of various products.
- The process flow can be simplified. The solution can be directly made into a powder product in one step in the drying tower.