22 
BULLETIN 1010, U. S. DEPARTMENT OF AGRICULTURE. 
flows into the general sewer, whereby any entrained oil may be recov- 
ered. If more than traces of moisture remain, the oil must be agi- 
tated and heated in order to dry it. The fuller's earth, previously 
weighed out in room e on the mezzanine floor over the tanks, is 
dropped into the oil in the tank C, which is covered during this opera- 
tion to prevent the spreading of the dust. After agitating for about 
half an hour, the batch is pumped through the filter press E and 
allowed to run back into tank (7 by the sliding funnel until the cloths 
Fig. 7.— Plan of an equipment designed for refining 2.5, 000 pounds of corn oil at one time. 
of the press have been covered and the oil flows clear. It is then run 
into tank F, which serves as a storage tank for the deodorizer. 
Up to this point each unit of the equipment has been large enough 
to handle a batch of about 25,000 pounds of oil. The deodorizer, 
however, is designed for only half of this quantity. In the first place 
the larger the batch of oil the longer it must be subjected to the deo- 
dorizing treatment. This treatment benefits an oil up to a certain 
point, but if it is continued beyond that point the oil deteriorates. 
The smaller installation also means a lower overhead in the nature 
of certain fixed charges. The distribution of labor among the several 
