(51d) Materials as Inherent Ignition Sources for Dust Explosions During Spray Drying

During spray drying a solution is dispersed through a nozzle in small droplets to evaporate the water by means of hot air. In a large number of these processes organic materials are processed so three out of four factors for dust explosions to occur are already present. The only thing missing for a dust explosion to occur is an ignition source. In order to prevent explosions in spray dryers we try to remove all possible ignition sources.

During spray drying large amounts of material can accumulate. These accumulations are exposed to high temperatures, can cause self heating and change into an ignition source for dust explosions.

In order to prevent your material changing into an ignition source you need to investigate the self heating properties of the material. From this you can deduct which amount of accumulation is safe in your processes and help you in designing inspection and cleaning schemes in order to prevent your material changing into an ignition source. This paper describes an overview of methods to asses your material as an ignition source and how you can use this information to prevent dust explosions in your spray drying processes.