MACHINERY AND PLANT 65 



The drying house (Fig. 1) which is used in 

 other tropical industries is often used for copra. 

 The floor A consists of thin perforated galvanized 

 iron sheets. The furnaces are fed with shell, 

 fibre, wood or other fuel, and the heat given off 

 by the flues C raises the temperature of the air 

 to about 70 C. The floor is charged and dis- 

 charged at intervals depending on the weather, 



FIG. l. 



the design of the plant, and its management; 

 usually twice a day. In more recent designs 

 steam piping is used in place of the flues, and 

 fans are used to circulate the air. 



Rotating drying cylinders and drying con- 

 veyors are also used. The tunnel dryer (Fig. 2) 

 is a great favourite in some districts. The green 

 copra is charged on to light pallets or frames A, 

 which are stacked on trucks B. A current of 



F 



