The Solar Dryer, Part 4: Construction

  There were few hand tools available at the farm, and almost none (except quite a few hammers) in working condition. The Taneeb family maintains a strangely large collection of—for example—old wire-cutters fused by corrosion into immovable wire-cutter-shaped hunks of iron. There were no power tools, and anyway no grid power at the farm. Fayez was able to borrow a diesel generator and a gigantic hammer-drill; and we purchased, among other things, a screwdriver, hand saw, sets of drill- and screwdriver bits for the power-drill. For one day, one student brought both a battery powered screwdriver and a circular saw.

Assembling the base and legs.

Assembling the base and legs.

 Use of the generator with the huge hammer-drill to drive #4 screws into up-cycled lumber was not the most efficient or ecological solution, but it made it possible to make progress quickly on the construction and complete the solar dryer in the time we had. After spending much of the two weeks on discussion, other activities with the larger Global Campus group, recovering and preparing the materials, tracking down and purchasing new materials when needed; the final design choices, cuts, and assembly took place in a dense, intense, and surprisingly well choreographed final few days. By this time, everyone had a clear idea of what we were doing, and the group worked smoothly to create the final product we had imagined together and prepared for.

This was when we realized that something was really taking shape.

This was when we realized that something was really taking shape.

 In addition to purchasing new fasteners (although many were recovered from the found lumber) we also bought new polyethylene sheeting, plastified metal mesh for the drying trays, and of course the solar panel. The three fans were recovered from old computers out of necessity; new 12V computer fans were simply not available in Tulkarm. I would have preferred to buy these new, and intend to replace them next time I visit the farm. Three kitchen strainers were purchased for use as inlet filters over the fans.

placing the main working surface

placing the main working surface

 The final product differs from the designs in Lorenz-Ladener in several ways: The roof is more peaked, simply because this is the way the students built it and I didn’t notice until after the roof beams were cut and assembled. Readers of this report should be aware that in Northern Europe, with less intense sunlight and lower ambient temperatures, this could be a problem; in Palestine, the inside of the dryer immediately reached temperatures of around 40C on a mild autumn day, despite the high roof and the light color of the dryer interior.

the team in consultation

the team in consultation

 

Our initial idea was to paint the floor of the dryer a slightly darker color—the recovered plywood we used had been painted white—or to lay brown paper on part or all of the floor. But as mentioned, the dryer quickly reached ideal temperatures as it was; we have left it for now. There is a thermometer in the dryer, and the Taneeb family will experiment with it to determine if we need to darken the Solar Dryer interior.

fabricating the trays

fabricating the trays

 Lorenz-Ladener make no mention of it, but in Tamera we learned that it was an absolute necessity to protect the Solar Dryer from ants. As in Tamera, we incorporated water-traps into the legs of the Solar Dryer.

Both the roof beams, and a tray, are visible here.

Both the roof beams, and a tray, are visible here.

 

 

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *