ARTIFICIAL DRYING OF FORAGE CROPS 7 



crops of different maturity, and for different methods of processing. 

 Other factors incidental to these observations were time length of the 

 drying run, drier-inlet and exit-gas temperatures, moisture content 

 of forage entering and leaving the drier, the weight of the material 

 entering the drier, and if possible the weight of the material leaving the 

 drier. When it was not practicable to obtain the weight of the 

 material both entering and leaving the drier the unknown weight was 

 computed from the known weight and the moisture content of the 

 forage (wet basis) before and after drying. Under normal operating 

 conditions it is assumed that the difference between the weight of the 

 forage as it enters and leaves the drier represents the water evaporated 

 and that the quantity of dry matter is constant. 



From observations and tests of the two driers at the Iberia Station, 

 which have been summarized in tables 1 and 2, the following is noted: 



1 . In drying alfalfa (whole) on the apron-conveyor drier the average 

 percentage loss in weight is about the same for the seasons 1932 and 

 1934. Not much forage was dried during the 1933 season. The 

 power consumed per unit weight of material dried, and per unit weight 

 of water evaporated was reduced in 1934 from that shown during the 

 1932 season. The same holds true for the heat requirements of the 

 drier per unit weight of material dried and per unit weight of water 

 evaporated, although the hourly output and evaporation weight do not 

 show an increase. This more efficient utilization of power and heat 

 in the apron-conveyor drier was due to the scheme of blowing the air 

 counter current to the apron travel for the first half of the apron length. 

 The intake and exhaust system on the apron-conveyor drier was 

 arranged so that the drying gases after first being forced through a 

 section of the apron might be drawn into a fan and then forced through 

 another section of the apron either toward the feed end or discharge 

 end of the drier. If the air moved toward the feed end the counter- 

 current system was obtained. If toward the discharge end (fig. 4), the 

 air moved concurrently with the hay. The air velocity through the 

 mat of forage ranged from 80 to 150 feet per minute in all of these 

 observations. 



