Principles of Spin Flash Dryer

Author: Svaar Process

Spin flash dryers are considered suitable for drying wet cakes, slurries, pastes that are usually difficult to dry in other dryers. The material is fed vertically to the drawing chamber by a screw feeder with a variable speed drive where it is heated by hot air and at the same time divided by a specially designed disintegrator. Air heating can be direct or indirect depending on the application. The dry powder is collected by a cyclone separator / bag filter or maybe a combination of both. The decomposed material is brought into contact with hot drying media, which dries the particles and pneumatically conveys them to separate in a hurricane or bag filter. The product clarifier ensures the desired size and leaves the dried particles only to dry chamber.

Flash Drying systems are in which particulate solids are dried during transport in a hot gas stream usually air or combustion gases. The simple flash drying system includes six basic components: the gas heater, the wet material feeder, the drying duct, the separator, exhaust fan, and a dried product collector. The wet particles are fed into the hot gas stream sometimes with special mixing devices. The stream flows up the drying tube. The gas velocity must be greater than the free-fall velocity of the largest particle to be dried. The gas velocity in relation to the particle velocity is high. Thermal contact between the conveying air and the solids as mentioned above is usually very short and therefore flash dryers are most suitable for removal of external moisture (surface moisture) and are less suitable for removal of internal moisture. At the end of the drying process a dust separation arrangement is installed. Spin flash dryer are easy procedures for the Drying Filter Pastes, Cakes, as well as highly sticky liquid.

Principles of Spin Flash Drying

  • Spin flash drying generally corresponds to an up-floated bed structure. A drying agitator acts as a rotor for breaking bundles and the hot air travels at reasonable elevated velocities to provide dynamic actions for disintegrating and drying the products
  • New and fresh air can be sucked through hot air producers which may be direct and indirect in the nature. The admission for drying the chambers is peripheral for giving rotating air suctions across the dryer. Liquid, Solid, or Gaseous fired are the hottest air producer.
  • A supply screw forces the material in the direction of the drying chamber. The rotor is provided from the bottom in the drying chamber. This rotor is a specially designed scraper disintegrator and blade for breaking lump mass for small pieces.
  • Using the rotor the broken lumps starts to dry and at the same time disintegrates with the flow of hot air.
  • The particles of aerated powder remain on top of the dry chambers that pass through the classifiers which classify them to the essential size. Particles with larger diameters return to the chambers, while the retracted pulse travels finely with air for final collection through a filter, through which about 100% powder recovery can be completed.

Applications where Spin Flash Dryers used:

  • Food items
  • Bleach clay
  • Ceramics
  • Organic chemicals
  • Organic salt
  • Agro chemicals
  • DCP gluten
  • Starch
  • Sugar factory
  • Pigments & Dyestuffs
  • Dye and dye intermediates

Spin Flash Dryer Manufacturer use Spin Flash drying technology of high-viscosity products, pastes and wet cakes. Industrial Spin Flash Dryer Manufacturer mostly prefers this process as it provides a faster and more energy-efficient alternative way to spray drying.