India is a major pulse producing country and accounts for 1/4th of worlds pulse production. Around 14 to 15 million tones of pulses are produced in India. There are 1400 pulses processing unit in the country which accounts for a large employment among rural and semi urban population. In the last decade the dal processing units due to space constraint have shifted from open drying to conventional fossil fuel fired dryers or processing unit. This brings more pressure to the already burden energy sector. Hot air at 60 -65 Deg C is used by buring diesal.
By using solar heated air at 60 Deg C , the firewood consumption for the Drier could be reduced. The solar heating unit saves fuel consumption around 60 to 80%. The system doesnt need big maintance except cleaning of glass which takes two hours of two workers for every week. The switching over from solar heating to conventional heating during rainy day is very easy. In nutshell the working of the system is satisfactory and it saves fuel consumption.
What is the PEN solution
Sanga Dal Mill has adopted to use solar heat to reduce diesel consumption. The south facing roof of the factory has been covered by 167 m2 area solar collector panel. On a normal sunny day the collector delivers hot air above 650C. A 3 Hp power blower is used to deliver the hot air from the solar panel to the point of usage. Insulated metal duct are used to avoid temperature losses. The System installed in 2001 to save 60 to 90 liters of diesel per day.