How to use the DRYIT semi-continuous tray dryer
Practical Action
The graph shown to the left (and featured earlier in the report) is an easy way of determining
the fuel use of the drying system. This graph though is for a particular drying condition of
ambient air of 18 °C, RH of 60% and a drying temperature of 50 °C. There will be slight
changes depending on the changing ambient conditions. However, for most purposes, the
graph shown earlier will be sufficient to obtain approximate fuel consumption values.
If the temperature lift is at about 60 °C, the for example if ambient is 20 °C and the desired
drying temperature is 50 °C, the approximate fuel consumption is
((50 – 20) / 50) x 1.6 = 0.8 gals / hr
However, a simple was to calculate the percentage time the heater is on and hence calculate
the average fuel consumption is to measure by observation using a watch.
References and further reading
Drying of Foods, Practical Action Technical Brief
Drying Technologies, Practical Action Technical Brief
Anagi Tray Dryer, Practical Action Technical Brief
Solar Drying, Practical Action Technical Brief
Drying Food for Profit: A Guide for Small Businesses Barrie Axtell, ITDG Publishing, 2002
Producing Solar Dried Fruit and Vegetables for Micro- and Small-scale Rural Enterprise
Development Natural Resources Institute, 1996
Drying Food For Profit: A Guide for Small Business, Barrie Axtell, 2002, ITDG Publishing
ISBN 1 85339520 X
Setting up a Food Drying Business: A Step-by-step Guide, Fabrice Thuillier, 2002, ITDG
Publishing, ISBN 1 85339 498 X
Drying Foodstuffs, Jean Françoia Rozis, 1997, Backuys Publishers
Construction and Use of a Simple Solar Dryer to Preserve Food for Off Season HEDON
Household Energy Network
Try Drying It: Case Study, Axtell B, et al, Intermediate Technology Publishing, London, 1991
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