What is the process of spray dryer？

The spray process of a spray dryer is a crucial step during which liquid materials undergo transformation into tiny droplets using atomization technology. This step significantly influences the size and shape of the final particles.

Here are the key steps involved in the spray process of a spray dryer:

1. Liquid Supply: Initially, the liquid material is conveyed from the liquid supply system to the spray dryer using equipment such as liquid storage tanks and pumps.

2. Liquid Atomization: Upon entering the spray chamber, the liquid material undergoes atomization through the spray system. This typically involves high-pressure nozzles, rotating disks, or similar atomizing equipment. There are two main spray methods:

   • Pressure Nozzle Atomization: Here, liquid materials are sprayed through high-pressure nozzles, forming tiny droplets. The adjustment of pressure and flow rate plays a crucial role in controlling droplet size.

   • Centrifugal Atomization: Alternatively, liquid materials can be sprayed towards a rotating disk or disc, forming a mist due to centrifugal force. This method proves effective, especially for handling sticky materials.

3. Atomized Droplet Formation: During atomization, the liquid material undergoes a transition from a large volume to numerous tiny droplets. Droplet size and uniformity are heavily dependent on equipment design and operating parameters.

4. Droplets Enter the Drying Chamber: Subsequently, the formed droplets enter the drying chamber, where they come into contact with hot airflow, resulting in rapid water evaporation and solid particle formation.

5. Particle Formation: As water evaporates, the droplets gradually condense into solid particles. Particle size and shape are controlled by atomization during spraying and influenced by factors such as temperature, humidity, and airflow velocity in the drying chamber.

6. Particle Collection: Finally, solid particles are expelled from the spray chamber and collected using a collection system at the bottom, such as a cyclone or bag filter.

In summary, precise control of liquid atomization, drying chamber temperature, humidity, and airflow speed is paramount to achieve the desired particle characteristics in the final product. Different applications may necessitate varying operating parameters and spray equipment designs.