A Brief on Spray Drying Process: Its Uses And Working Method!!

Posted by Enurga on May 4th, 2019

Spray drying is basically a method of producing dry powder from a liquid by rapidly drying it with a hot gas. This is one of the most preferred methods of drying many sensitive materials including foods and products of pharmaceuticals. These days, many different industries including dairy production, pharmaceuticals, optical diagnostics, and many more industries are utilizing spray drying methods for drying some of their liquid products into the dried state. Unlike some other drying methods that create cakes which further requires grinding and sizing, a spray drying method can make free-flowing particles with narrow size distribution in its first attempt.

The feed that is used for spray drying the liquid can be a paste, suspension or a solution and can easily be modified into granules, powders or agglomerates. Once any product is spray dried, its finished form largely depends on various factors including physical and chemical properties of the feed and the design and operation of the spray dryer.

Spray drying working process

Atomization:

The method of spray drying usually starts with a process named as atomization where a nozzle turns the liquid substance into small liquid droplets. In this step, various types of feeding systems can be used to atomize the liquid such as two-fluid atomization, high-pressure nozzle or a rotary atomization. In most of the spray drying cases, the degree of atomization can be changed to increase or decrease the liquid droplet size of the feed.

Drying process:

After the atomization of the liquid gets completed, the drying process takes place. When the liquid droplets exit the nozzle of the dryer, they are then dried to form a powder in order to get packed and transported. The drying of the powder is generally done using air that is heated from natural gas.

Recovery process:

The recovery process is the final stage in the process of spray drying in which the powder gets recovered with the use of separation equipment known as a bag filter. The powder is then collected followed by the steps of cooling and packaging.

What is the purpose of a spray drying method?

Spray drying is one of the most flexible processes that can provide quick and instant results. This process can easily resolve various drying issues that take place with sensitive materials including food ingredients and other related items. These days, several types of spray dryers’ are available each having different features and characteristics. Besides, some major parts of a spray dryer include a feed pump, a nozzle, air heater, air dispenser, process control systems, drying chamber, and powder recovery systems.

However, to ensure that you are getting powder particles that have no imperfections, you just need to have a good collection of solid content, required amount of information on drying kinetics and proper understanding of the atomization method. Having all these will ensure that you’ll get amazing results and that too without any imperfections and mistakes.