Drying Coffee 75 



circulation of cold air, I think it wise to 

 mention that I have come across some planters 

 who put as much faith in the amount of dry air 

 in the drying cylinder as in its temperature. 

 I might also remark that the majority of 

 planters increase the speed of the fans given by 

 the manufacturers with excellent results. 



When generating heat by means of a direct Saving 

 fire heater a certain amount of fuel can be saved fuel - 

 in the following way. If the chimney of the 

 heater runs vertically through the building it 

 may be jacketted, and the jacketted space con- 

 nected by means of piping to the inlet of the 

 fan ; the result would be that the surrounding 

 hot air between the chimney plates and the 

 outer casing would be drawn into the heater by 

 the fan, thus the minimum amount of fuel 

 would be necessary to heat this over to the 

 required temperature, therefore an economy in 

 fuel would be experienced. In order to main- 

 tain the highest efficiency of the heated air, 

 particularly referring to the Guardiola dryers, 

 in which, due to their design, the air has to 

 travel through a considerable quantity of piping 

 before it enters the drying drum, the hot-air 

 piping could be covered with asbestos rope. 

 This is not necessary with the Okrassa dryer, 

 because the air is forced into the drying drum 



