fruits of the silk road - facilitating east west trade

Electrical cabinet drier

The electrical cabinet drier is simple to build from readily available plywood and other materials.

Operation:

The cabinet can dry 50kg fruit in 24 hours at 50 celcius. Timer is set by timer on wall socket. Temperature is set by thermostat on electric convector heater. Air flow is provided by bathroom fan.

Fruit is pre-treated as appropriate, and then loaded one fruit thick onto drying trays. Cabinet is closed. After 12 hours, trays are rotated to ensure even drying.

When fruit is no longer sticky to touch, it is removed for equilibration.

Construction steps:

1. 5 sheets of standard 1.5*1.5*.006m plywood are cut in half. 2 of the half-sheets are cut in half again to give 4 pieces of size .75*.75*.006. 2 of the half sheets are further reduced in size to 1.5*.71*0.006m.

2. A circular hole is cut in the middle of the .75*.75*.006 pieces to accommodate the top and bottom air vents.

3. The sheets are edged with straps of .02*.03m. Foil backed fibreglass batts insulation, of 0.03m thickness, is fitted to the area between the edging straps. A same sized piece of plywood is sandwiched on top.

4. The 2 of 1.5*.71*0.006m pieces are edged with the strap and filled with insulation. Reinforcing straps are placed to accommodate hinge screws. The two edged pieces are then placed in the middle of two 1.5*1.5*.006m plywood sheets. These will form back wall and door.

5. The 2 of .75*.75*.006 sandwich pieces are then fixed to top and bottom ends of 2 of 1.5*1.5*.006m pieces to create rectangular frame. Back piece of 1.5*.71*0.006m then fitted, and second 1.5*.71*0.006m fitted for door. Hinges and closure added.

6. 10 mesh drying trays of dimensions .69*0.69*.02 are then constructed. Supports are placed on side walls.

7. Bathroom fan fitted to centre of cabinet.

8. Electric convector heater (500W) placed in base of heater, with drip tray above. Drip tray place in base of drier. Cables run through lower air vent.

9. 4 castors fitted to base of cabinet.

10. Flexible hose run from top air vent to outside.

Material List