Ring Dryers Ring Dryer

Provides control of residence time and particle size; resulting in efficient and even drying.

The presence of a "manifold" or "internal classifier" and it's position in the Ring drying system is what differentiates it from the Flash dryer and other Ring Dryers. The manifold provides selective recirculation of semi-dry material, lowering exhaust temperatures, increasing efficiency and improving product quality. When used in combination with one of GEA's proprietary disintegrator mills, the system provides control of residence time and particle size resulting in efficient and even drying.

The Ring Drying Process

The manifold uses the centrifugal forces created through passing a product containing airstream around a curve to concentrate the product into a moving layer. The adjustable splitter blades are used to cut this layer and return the heavier, semi-dried material back to the hot air stream at the inlet of the dryer for another pass through the system while the lighter, drier product exits the manifold and proceeds to the product collection system. Manifolds can have single or multi classification blades and are often used in combination with disintegrators for greater control of particle size, product moisture and exhaust temperature.

This selective extension of residence time enables the Ring Dryer to process many materials which were traditionally regarded as difficult to dry in a Flash Dryer. Depending on the specific application, GEA offers custom designed systems based on proven configurations and technology to provide flexibility in design and optimal performance.

The Ring Dryer has been used to dry products in many industries including food, chemical, mineral and plastics. A broad range of feed materials including powders, cakes, granules, flakes, pastes, gels, and slurries can be processed. For slurries, pastes, or sticky materials, our specifically designed feed system allows back-mixing of the wet feed with a portion of dry product to produce a suitable conditioned material for feeding into the dryer. Special extrusion systems are also used for viscous products such as vital what gluten.

 

Features

  • Multi or single stage classifier
  • Choice of various disintegrators and dispersers
  • Choice of a buffer hopper or back-mixing system if required
  • Product recirculates to hottest air
  • Feed introduced at reduced inlet temperature
  • Can be designed for open circuit, partial gas recycle and SSD™
  • Can be designed for operation in an inert atmosphere

Benefits

  • Uses centrifugal forces to provide extended residence time for the heavier wetter particles while allowing the lighter dryer particles to be transferred to product collection
  • Use of the disintegrator/disperser in combination with the manifold provides close control of particle size, product moisture and exhaust temperature to ensure the best product quality
  • Flexibility to work with different dewatering systems and to enable use with friable and non-friable wet feeds
  • Provides the highest driving force to minimize required airflow and resulting dryer size and fan power.
  • Reduces risk of thermally damaging product quality
  • Enables energy savings and system integration
  • Suitable for operation with solvent and recovery thereof.

 

Process Flow Diagram

Full Ring Dryer