ARTIFICIAL DRYING OF FORAGE CROPS 



15 



SLIDING RINGS 



Steel 



g rings 



Figure 8.— Cylindrical furnace, with sliding rings for controlling air flow. 



POWER REQUIREMENTS 



In a forage drying plant, power is needed for the following purposes: 

 CI) Processing the undried forage. This includes chopping, chop- 

 ping and shredding, or crushing depending upon the type of drier and 

 the operator's preference. 



(2) Transporting the dried forage to a storage structure or proces- 

 sing plant either by a drag conveyor or a pneumatic system or a com- 

 bination of both. 



(3) Conveying the drying gases to the drier from the furnace, and 

 removing them after they have performed their work in vaporizing 

 the moisture from the forage. 



(4) Miscellaneous uses such as operating fuel pump and blower for 

 the burner, rotating the drum or actuating the apron conveyor of the 

 drier, operating the unloading hoist, baling or grinding the dried 

 material, etc. 



The choice of the power unit depends somewhat on its availability 

 and the cost per unit of energy. From the standpoint of convenience, 

 electric power has the advantage. Where electric energy is available, 

 in most instances the rates are low enough so that it can be used 

 profitably. 



Apron-conveyor driers are not adapted to handling finely chopped 

 forage, especially the single-apron machines, because the apron screen 

 allows a considerable portion of the material to drop through and 



