Wood & Furniture

Development of solar-enhanced dryer plants for agricultural and forestry products in Brazil

As part of this project, the participants developed a solar dryer and constructed two major plants for wood drying. These are the world's largest solar wood drying plants. The project partners revised and adapted the control system to facilitate use of the dryer for other goods such as medicine plants, manioc and coffee. 

 

Summary

Presently, the Brazilian market lacks suitable drying methods for many important agricultural and forestry products. This results in substantial quality impairments and post-harvest losses.

The project therefore aimed to develop and produce at industrial scale an economically and energetically adapted dryer plant for the Brazilian market. For demonstration purposes, several solar-enhanced dryer plants for agricultural and forestry products such as lumber (particularly eucalyptus), medicine plants, manioc and coffee were constructed and examined. For greater understanding of the physical correlations and to facilitate prediction of the plant behaviour under different weather conditions as well as for expansion of the solar plant's scope of application, a simulation program was developed and tested.

Results:

  • The drying experiments using eucalyptus wood showed that both the electrical and the thermal energy consumption as well as the drying costs were reduced by 40 to 60% compared with conventional plants.
  • Compared with traditional sunlight or outdoor dryer methods, product quality was substantially improved.
  • With an annual drying capacity of 35,000 m³, the world's largest solar-enhanced dryer plant was built. Series production was initiated.
  • The computer simulation was able to supply important findings in terms of further distribution of the dryer plant in other climate zones.
  • Furthermore, a low-cost, microprocessor-controlled climate control system that is easy to adapt to different requirements was developed.
  • Wood that is very difficult to dry could be dried without loss of quality to a final moisture content of 10 to 12% as is required for local furniture production.

More Project Informations

Project number:  0329759

Project period:  1997 - 2000

Project region:  Germany (Baden-Württemberg), Brazil

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Source: German National Library of Science and Technology Hannover (TIB)