Solar dryer

Solar dryers are devices that use solar energy to dry substances, especially food . There are two general types of solar dryers: Direct and indirect. [1]

Direct

Direct solar dryers exposes the substance to be dehydrated to direct sunlight . Historically, food and clothing was dried by using lines , or laying the items on rocks or on top of tents. [2] In Mongolia cheese and meat are still traditionally dried using the top of the ger (tent) as a solar dryer. [3] In these systems the solar drying is assisted by the movement of the air (wind) that removes the most saturated air of the items being dried. [2] More recently, complex drying racks [4] and solar tents [5] [6] were constructed as solar dryers.

One modern type of solar dryer has a black absorbing surface which collects the light and converts it to heat; the substance to be dried directly on this surface. These driers may have enclosures, glass covers and / or winds to in order to increase efficiency . [7]

Indirect

In indirect solar dryers, the black surface heats incoming air, rather than directly heating the substance to be dried. This heat is then passed over the substance to be dried and exited up often by a chimney , taking moisture released from the substance with it. [2] They can be very simple, just a cold tilted frame with black cloth [8] to an insulated brick building with active ventilation and a back-up heating system. [9] One of the advantages of the indirect system is that it is easier to protect the food, or other substance, from contamination or wind-blown by birds, insects, or animals. [2] [9]Also, direct sun can chemically alter some foods making them less appetizing. [2] [9]

See also

  • Solar cooker

References

  1. Jump up^ Norton, Brian (2013). Harnessing Solar Heat . Springer. ISBN  978-94-007-7275-5 .
  2. ^ Jump up to:e Heinz Gunter & Hautzinger, Peter (2007). “Meat drying”. Meat processing technology for small- to medium-scale producers . RAP Publication 2007/20. Bangkok, Thailand: Regional Office for Asia and the Pacific, Food and Agriculture Organization of the United Nations. ISBN  978-974-7946-99-4 . Archived from the original on May 23, 2010.
  3. Jump up^ Oyunbayar, N. “Mongolian Food: Meat, Milk and Mongolia” . Mongoluls.Net. Archived from the original on 5 April 2005.
  4. Jump up^ Shaffer, Marcella (1999). “Solar Food Drying” . Backwoods Home Magazine . No. 58. Archived from the original on 16 August 2000.
  5. Jump up^ Trim, DS & Curran, CA (1983). “Solar dryers”. Comparative Study of Solar and Sun Drying of Fish in Ecuator . London: Tropical Products Institute. ISBN  978-0-85954-158-9 . Archived from the original on September 2, 2015.
  6. Jump up^ Olokor, Julius Oghenekaro & Omojowo, Funso Samuel (2009). “Adaptation And Improvement Of A Simple Solar Tent Dryer To Enhance Fish Drying” (PDF) . Nature and Science . 7 (10): 18-24. Archived (PDF) from the original on September 2, 2015.
  7. Jump up^ Fodor, Eben (2006). “Build a Solar Food Dehydrator” (PDF) . Mother Earth News . Flight. 2006 no. August / September. pp. 66-70. Archived from the original on September 2, 2015.
  8. Jump up^ Robishaw, Sue (1999). “Drying Food with the Sun” . Countryside & Small Stock Journal . 1999 (July / August). Archived from the original on September 2, 2015.
  9. ^ Jump up to:c Weiss, Werner & Buchinger, Josef (2001). “Solar Drying” (PDF) . Austrian Development Cooperation and Institute for Sustainable Technologies (AEE INTEC). Archived (PDF) from the original on 26 May 2012.

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