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BULLETIN 1166, U. S. DEPARTMENT OF AGRICULTURE. 
In the United States the steam-heated rotary dryer (Fig. 1) seems 
to be held in greatest favor, owing to the absence of danger from 
scorching the product. The pomace is run first through a picker and 
then through the rotating drum which is the real dryer. From the 
lower end of the drum the dried pomace is conveyed to the storage 
bin. The older slatted-floor kiln, commonly used in the evaporation 
of apples, is also employed in drying pomace. 
A simple calculation serves to show that 1 ton of dried pomace 
with a moisture content of 10 per cent can be obtained from 4^ tons 
of wet pomace containing 80 per cent of moisture. 6 
In France it has long been the custom to recover the apple seeds, 
which are sold to orchardists and nurseries. Elutriation is some- 
Fig. 1. — Steam-heated rotary pomace dryer. 
times used for this purpose. This separation is also accomplished by 
shaking machines, fans, or winnowers which are put into operation 
after the water content of the pomace has been reduced to 25 per 
cent. Precautions must, of course, be taken not to impair the via- 
bility of the seeds by letting the temperature become too high. 
The cost of drying pomace containing 65 to 70 per cent of water 
down to a moisture content of 12 to 13 per cent is given by War- 
collier {138) as 3.5 francs per 100 kilos ($6.14 normal exchange per 
ton) of the dried material. 7 This agrees with a recent estimate on 
the cost of drying obtained from an American authority, who states 
that with a steam dryer of the rotary type, capable of handling be- 
tween 21 and 24 tons of wet pomace in 24 hours, and a consequent 
output of from 5 to 7 tons of dried pomace, the cost of drying will 
e Under present conditions of American factory practice, pomace which has been 
pressed a second time in the manufacture of vinegar stock contains from 74 to 78 per 
cent of moisture. This means that from 3^ to 4 tons of the press cake will yield 1 ton 
of the dried product 
7 This refers to conditions in. France just before the World War. 
