12 BULLETIN 867, U. 8. DEPARTMENT OF AGRICULTURE. 
the height of the racks. By adjusting the slides at the bottom, 
controlled by levers, the discharge may be made continuous or 
intermittent. Usually the latter practice is followed. 
The heating is effected by rismg columns of hot air. This air-is 
drawn in by a fan at the bottom and side of the bean-holding equip- 
ment and passed over hot closed steam pipes. ‘To prevent the beans 
from drying out, and also to increase the heating effect of the hot air, 
ft 
fl 
F 
z 
4 
4 
Fb 
2 
a 
Fic. 3.—Bean racks, showing steel uprights Fia. 4.—Section of bean rack showing it (at the 3 
and shelves, saddles, and slide levers. left) discharging at intervals and (at the right) 
Every surface on which beans are sup- right) in continuous flow. By throwing the 
ported is inclined so the beans and dust small levers at the bottom of the racks the 
will flow out when the slides are open, method of discharge is instantly changed from 
leaving the racks clean. These racks are one to the other. The upper large lever oper- 
of smooth galvanized steel and are fitted ates the slides for discharge at intervals, but ; 
un closely, without bolts. is not used when the beans are flowing con- 3 
tinuously. ; 
a jet of live steam is sometimes introduced into the hot-air stream as 
it emerges from the nests of steam pipes. It is found that an air 
temperature of about 180° F. will raise that of the beans when deliy- 
ered to the machines to about 110° F. 
‘Although the above is a method of procedure now followed in com- 
mercial practice, it might be well to consider the followmg facts with 
regard to improved operation. It is generally conceded in expeller 
practice that better oil yields are obtained when appreciable quan- 
