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McMullin & Co
Florence Diemont


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The sun-drying case

The sun-drying case on our grounds has undergone a fundamental revision after 10 years. It's not that it no longer works properly; but rather it's just that the wood frame was wearing out in places. Luckily, a lot of work was saved by a hardening process that involves using pieces of wood covered with a polyurethane layer. At the moment when we were busy making our box young again, we received a phone call from a friend and supporter in equatorial Africa...They want to make sun-drying box here. Do you have a suitable design?? he asked. We immediately drew up a design, and what we came up with is the following:
In the first place, the sun-dryer we use was intended for use in our region (northern Europe). Consideration was made for an angle of from around 58°, which we use to denote the average position of the sun in the spring, summer and (early) fall. The sun-drying case is made in such a way that direct sunlight cannot reach its contents (vegetables) and therefore no quality is lost, which is especially important with mushrooms. In our sun-drying case there is as much a warm convection stream as radiant heat*, the latter resulting from the (painted) black metal plates (we use an old aluminum offset plate (size A1)) behind the glass, which serves as a repository. The plate is positioned in such a ways as to leave an opening on the top of the case (of around 10 cm), through which the hot air streams into the box. Deeper inside the box is a partition with a comparable opening, which opens out under the lower drying rack. Via this opening the (moist, cooler) air is sucked out of the box; this occurs as a result of the flue in the top of the box. We use a short flue of approximately 1 meter in length, which in practice works very well. The Plexiglas tube is sealed off from the innermost tube.

The box is made of concrete-plex (plastic multiplex). The box is made so that it can rotate. Inside there are five drying racks, covered with wire screens. Underneath is the largest rack: 100 x 110 cm. The smallest rack, on top, is much smaller: 55 x 110 cm.



Our 'equatorial drying case' is square-cornered and has five equal-sized drying racks of approximately 100 x 100 cm and a sun-collecting pointed roof, which catches the sun's rays when the sun is medium-high in the sky and also late in the afternoon. The sun flues are placed at an angle on the sun-collecting roof; we recommend that angle to be 45° to 50°. Further construction and operation is the same, except that the zenith case does need to be rotated.