What Are The Different Aspects Of Spray Drying?
The method of producing a dry powder from a liquid by rapid drying with a hot gas is known as spray drying. Many thermally sensitive materials such as foods and pharmaceuticals prefer this method of drying. All types of spray dryers are using some of atomizer or spray nozzle for the dispersion of liquid or slurry into a controlled drop size spray. The first stage drying generates fine powders which can be recycled in continuous flow at the top of the chamber. The drying of powder is finalized on an external vibrating fluidized bed.
Spray drying does not produce a full microencapsulation and it is used to change a liquid into a powdered form. The spray drying process creates a dispersion or emulsion of an ingredient within another ingredient. It is creating a dispersion or emulsion of an ingredient within another ingredient. It then dries this emulsion very quickly. Spray drying services are provided at an easy cost and there are companies specializing in the services.
Key points in the process of spray drying
· The process is effectively turning liquids into powder
· The spray drying process starts with an emulsion or dispersion
· The spray dried materials are not fully encapsulated
How does the process of spray drying works?
There can be many facets to this complex process. There are different types of spray dryers with different features to meet the various spray drying requirements. They are mainly used for food products, chemicals, and pharmaceuticals.
The basic parts of the spray dryer –
· Feed Pump
· Atomizer or Spray Nozzles
· Air Heater
· Air Dispenser
· Drying Chamber
· Powder Recovery Systems
· Process Control Systems
The first step in the process is “atomization”. In this process, a nozzle or rotary atomizer turns the liquid feedstock into small liquid droplets. Also, many of the desired qualities for the final product like particle size and viscosity are developed.
The next process is “drying”. Once the droplet exits the nozzles, they need to be dried to form a powder that can be easily packed & transported. Powder drying is done using air that is heated with natural gas. Final moisture of the powder is controlled by fine-tuning the hot air temperature.
The “recovery” is the final process and its take minimal time to recover the powder from the exhaust gas using a bag filter or cyclone.
The Principles of Spray Drying
The basic principle hinges on water removal and the removal of water make a significant difference in the total product quality. A primary starting point needs to be considered for determining the product moisture and particle size requirements. It also impacts the atomizer choice. The other factor is the used type of dryer. You must have more surface area for drying if it is a tall form dryer. It impacts the achievement of product specs. The services should be carefully selected for getting the optimum result.
