THE PRODUCTION OF CORN OIL. 11 



a day for each press. These figures do not include the cost of re- 

 pairing the cloths, which must constantly be done in order to make 

 the set last 60 days. In the expellers this expense is eli m inated. 

 It is estimated that the cost of repairs on an expeller amounts to 

 about $200 a year, or about 66 cents a day. It is evident, there- 

 fore, that the replacing of parts in the expeller costs less than the 

 press cloths for a press. 



It is estimated that the presses will deliver 1,400 pounds of oil 

 in a 24-hour run, which is the oil equivalent of about 1,000 bushels 

 of corn when degerminated by the wet process. The expeller will 

 deliver 3,000 to 4,000 pounds of oil in 24 hours, or the equivalent of 

 2 ,400 to 3,000 bushels of corn. The capacity of the expeller, therefore, 

 is much greater than that of the press. However, the power required 

 to operate the expeller is much greater, and the depreciation of the 

 machine is also greatly in excess of that of the presses. The one 

 great advantage of the press over the expeller is the exceedingly 

 low upkeep and the practically indestructible character of the 

 machine. 



HANDLING AND DISPOSING OF THE CRUDE OIL. 



FILTERING. 



Crude corn oil as it comes from the exyellers or presses is pumped 

 through filter presses, which remove the fine meal and other sediment 

 which has had time to settle. It is then placed in storage tanks until 

 shipped. 



BUYING AND SELLING. 



Operators who do not themselves refine the oil sell it to refiners, 

 soap makers, brokers, and in some cases to bakers. The use of crude 

 corn oil for industrial and edible purposes will be considered later. 

 The price obtainable depends largely on the grade of the oil, and 

 especially on the amount of free fatty acids present. Prime crude 

 oil is usually limited to not more than 2 per cent of free fatty acids. 

 The next lower grade must not as a rule contain more than 3.5 per 

 cent. Refiners protect themselves from a heavy refining loss by 

 paying less for an oil which contains such acids in excess of the 

 specified quantity. Under normal operating conditions with average 

 corn the crude oil contains from 1 to 3 per cent of free fatty acids. 

 It appears that the oil from wet-process germs has a somewhat higher 

 percentage of free acids than that obtained from dry-process germs. 



Large refiners, in order to have enough to supply the demand for 

 their refined oil, have found it profitable to buy considerable quan- 

 tities of the crude oil and refine it in addition to their own production. 

 Producers who market their . refined oil as package goods for the 

 retail trade find this practice especially desirable in order to supply 

 the demand created by their extensive advertising. This practice 



