Belt dryer

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The belt dryer is an apparatus used in thermal process engineering for the continuous drying and cooling of bulk goods, pastes, fibers, molded parts and panels with the aid of air, inert gas or flue gas. A special application of this device allows the shrinking of PE film or POL film in the packaging or printing industry (see also shrink film packaging ).

functionality

The belt dryer or belt cooler is an apparatus for particularly gentle product treatment. The wet material is fed continuously and evenly into an inlet chamber and mostly runs through the drying chambers on horizontally arranged, perforated drying belts. Heating gases flow through or over it and dry. The drying room is divided into several chambers, each of which can be equipped with a circulating air fan and a heating register. Each dryer cell can be controlled individually. The product flow velocities of the drying / cooling air can be varied in each cell. In addition, the transport speed of the goods to be dried can be varied, which gives an additional parameter for setting the drying time of the goods. The cells can be heated or cooled directly or indirectly, using all heating media such as oil, steam, hot water or hot gases.

Design features

The belt dryer is designed according to the modular principle . Each belt dryer consists of the inlet head, the dryer cells and the outlet head. There are various types of dryers such. B.

  • Cover dryer
  • Multi-stage dryer
  • Multi-day dryer
  • Multi-belt dryer

Ventilation variants

A basic distinction can be made between throughflow and overflow dryers. Depending on the treatment process, the direction of flow can be selected from top to bottom, from bottom to top, through or laterally across the product.

Exemplary conveyor belt variants

  • Chain-guided wire mesh belt
  • Chain-guided hinge plate conveyor
  • Chain-guided sheet metal belt
  • Chained wire mesh tape

Product task variants

  • Roller granulator - filter cake or shapeless or pasty products
  • Swivel belt - sensitive, pourable products
  • Distribution screw
  • Rotary arm feeder - dimensionally stable products
  • Plate task

Typical use cases

The belt dryer is used in the following industries:

  • Chemical industry
  • Pharmaceutical Industry
  • Food and feed industry
  • Stone and earth industry
  • Plastic industry
  • Wood industry (e.g. veneer dryer)
  • Ceramics industry
  • Printing industry

Product examples

Wood veneers , wood fiber insulation boards , color pastes, molding compounds, synthetic rubber, superabsorbents , stearates , catalyst compounds, coke, fruit, vegetables, herbs, cereals, wood chips .

literature

  • Klaus Sattler: Thermal separation processes. 3. Edition. Wiley-VCH, Weinheim 2001, ISBN 3-527-30243-3 .
  • J. Draxler: Script for the lecture thermal process engineering. Montan University, Loeben 2002.
  • O. Krischer, W. Kast: The scientific foundations of drying technology. (= Drying technology. Volume 1). 3. Edition. Springer, Berlin 1992, ISBN 3-540-08280-8 .

Individual evidence

  1. ↑ Bernd Thier: Apparatus: Technology - Construction - Application. 2nd Edition. Vulkan – Verlag, Essen 1997, ISBN 3-8027-2172-1 .