Spray Dryer

Prepare the Feed Solution: The feed solution is made up of a liquid like water or a solvent along with the product. The various ingredients of the product need to be thoroughly mixed together to ensure a homogenous mixture. It is important to balance the ratio of water/solvent with the product. Insufficient liquid can result in a thick slurry that does not atomize effectively, and too much liquid will increase energy costs as more heat is needed for evaporation and powder formation.

Set Up the Spray Dryer: The spray dryer must first be set up prior to use, this can include placing the equipment in the correct positions as per the system flow diagram and connecting the required piping and power lines to the various components and subsystems.

Load the Feed Solution: Once the feed solution has been mixed it can be transferred into the feed solution tank. Make sure that no contaminants are brought into the mixture during the loading process. Some feed tanks may already have the capacity to prepare the feed solution in situ, removing the need for a separate loading activity.

Adjust Operating Parameters: Key parameters such as feed pump flow rate, drying air temperature, and air flow rate must all be set. These values depend on factors such as the viscosity of the feed solution and the desired particle size.

Start the Air Flow and Heating: Many industrial air dryer systems will have a pre-defined start up process which only requires the operator to start the plant. Usually these systems will activate the drying air flow and air heater first to ensure the drying chamber has reached the required operating condition.

Begin Atomization: The solution is atomized by pumping it through a nozzle. There are many different nozzle designs such as: rotating disc, pneumatic, pressure, and ultrasonic. The end goal of all of these designs is the same, i.e., disperse the solution such that evenly sized droplets are formed.

Monitor the Drying Process: Low production rates, poor size distribution, and product sticking to the equipment are all signs that the drying process is not working correctly, monitor all the parameters and ensure they are maintained at their optimum operating points.

Collect the Product: The dried product can either be collected once a batch of feed solution has been processed or it can be collected, packaged, and stored if the process is continuous in nature. Finished product is usually collected from a cyclone that collects the material from the air stream.

Shut Down the System: Once the product has been collected the system can be shut down. Systems must be shut down in sequence, starting at the beginning of the process and shutting down subsequent equipment and subsystems until the entire system has been shut down.

Clean the Spray Dryer: Before performing any cleaning activities, make sure the system has been locked and made safe to work on. The types of cleaning processes are based on the size of the system, the feed solution, and relevant industry standards.