Spray Dryer - Technology and Art!
Spray Dryer is both art and technology. The technique transforms a fluid body into a dry powder/granule form using an atomization process inside a heated chamber. The reduction of the wet slurry into small individual droplets is called Atomisation. With sufficient retention time inside the spray dryer chamber, the water evaporation continues until the desired moisture content is obtained.
Several factors are involved in setting up the drying process. The final target moisture is the most fundamental factor. Other factors include the color, flavor, particle size, bulk density and flow properties. The end product qualities are very important depending on the application. For example, in case of a beverage the ability of the powder to sink and disperse in water is decisive to the success.
Achieving results from Spray Dryers
While the spray dryer fundamentals may seem simple, a lot of planning is required to achieve the right results in terms of formulation. The end powder formula to be achieved has a huge impact when it comes to the design of the drying conditions. In food and beverage it means, for example, a low density verses a high density powder, a low fat verses a high fat powder, a low protein verses a high protein product. The designs may differ based on whether the powder will be used in a dry mix or in a mixed in a hot liquid or will flavor a cold beverage. The emulsified powder should be able to to retain its integrity and properties in the target pH environment where its ultimately used. For products such as dyes, it is important to consider if environmental characteristics that need to be considered in the design of the product.
Factors such as hydration rates, relative particle size must be considered in order to provide necessary overruns. Drying considerations also include slurry feed, the type of atomizer nozzle and its configuration, air supply system, heating conditions, and transport for packaging.
Spray Dryer Conditions
Plant trials are the litmus test and must be conducted prior to introducing a powder formulation in a plant environment. The pilot plant study will help to establish and validate the spray dryer conditions. The parameters help to gain a better understanding of the behavior of various elements such as slurry solids, process or inlet outlet temperatures, feed drying rates, moisture content changes and the bulk density. The powder produced in the pilot plant can then be tested for performance attributes that are desired in the application of the product. Shachi Engineering has a full scale pilot plant in Pune, India that includes spray drying capabilities for production of small scale samples for customer evaluation prior to scale up to production.
What are Your Spray Drying Needs?
Please contact our representative to discuss product development efforts. Our sales team and Technical Staff can assist you in the design of a powder for any of your customized applications.