Applications

Spray drying

Spray drying is a process whereby liquid is atomised in a warm flow of air. During this process, suspensions and/or solutions are sprayed in small droplets. The great increase in surface area leads to a speedier transfer of substances and heat between the droplets and the carrier gas.

This approach is used in the production and processing of industrial products such as washing powder, rubber and sintered materials (e.g. aluminium oxide). It has thus become one of the most widely used applications.

Basic principle
The fluid is atomised into a hot stream of gas where the solid content within the droplets dries as it falls to the bottom of the chamber. It is not unusual for particles between 20 and 200 micrometres to be generated.

The aim of spray drying is to achieve as compact a droplet size distribution as possible in order to reduce the undesirable fine or coarse proportion to be sieved out of the dry product as much as possible.

A fluidised bed that forms part of the spray-drying process enables a more precise regulation of the core size and processes, such as product agglomeration.