Copra and its Preparation 405 



The tunnels are some 35 ft. in length, 4 ft. 

 in width, and 5 ft. in height. The drying 

 trucks upon which the nuts are to be spread 

 are fitted with trays of expanded metal or 

 strong wire netting. These trucks run on 

 bearings and can be moved about with ease. 

 The hot air from the " Chula " patent heater is 

 forced by a fan into one end of the tunnel and 

 is exhausted by regulated outlets at the other 

 end. Being under pressure the air flows 

 evenly along the tunnel and is in contact with 

 the nuts on both sides of the trays, thus 

 ensuring an even and positive rate of drying. 



The " Chula" patent air heater has been 

 developed in connection with tea drying and is 

 a simple and highly efficient apparatus. Any 

 kind of fuel can be used in the furnace, but 

 the makers strongly recommend charcoal as 

 being the cleanest and most economical 

 fuel; as in tea drying the pure carbonic 

 acid fumes from the burning charcoal are 

 cooled to a normal temperature and passed 

 through valves to mix with the hot air, of 

 which a large volume is heated by passing- 

 through tubes placed over the furnace. Except 

 for slight losses by radiation every available 

 unit of heat in the fuel is utilized, thus giving 

 the exceptional economy for which this heater 

 is noted. 



Coco-nut shells make first-rate charcoal and 

 naturally this kind would be used for copra 

 drying when possible. Where any difficulty is 



