CASTOR-OIL INDUSTRY. 9 
not ¥et Houghton the above-suggested basis, but sooner or later such 
will doubtless be the practice. The only objection to this seems to 
be the desire of those interested not to change present methods, 
fearing that complications would be added to transactions unfavor- 
able to growth in trade. 
MANUFACTURE ‘OF CASTOR OIL. 
CLEANING. 
The castor beans of commerce come mixed with such amounts of 
trash that it is absolutely necessary to remove this at the earliest 
stages of the. operation. An ordinary grain cleaner is used, with 
special perforations in the screens for castor beans. These cleaners 
are a combination of screens and fans, which remove the straw, 
hulls, and dirt in successive operations of sieving and fanning and 
deliver the cleaned beans. Such machines vary greatly in size, 
with attendant capacities of 30 to 1,200 bushels of beans per hour. 
DECORTICATION. 
“Owing to the peculiar structure of the castor bean, its millmg 
technology has developed along lines peculiar to itself. Several 
special machines have been built to decorticate castor beans. The 
process depends on cracking the brittle seed coats between rolls set 
so as to exert a cracking pressure rather than a crushing and mangling 
one. The beans with their broken seed coats are dropped on a 
shaking screen which serves to shake the kernels out of the adhering 
seed coats and otherwise loosen up the mass. As the charge falls 
over the end of the shaker, a current of air blows out the seed coats, 
_ while the kernels fall into a hopper below. 
It is very difficult to make a perfect separation of hulls from kernels 
by the mechanical decortication of castor beans as they are usually 
delivered from the warehouse. One of the factors contributing to 
this difficulty is the irregularity in the size of the beans, the small 
ones dropping between the rolls unaffected, while the large ones are 
crushed. This requires a grading of the beans, which of course can 
readily be done mechanically. 
Such decortication would be all the better effected if the beans 
were given a preliminary drying, such as could easily be accomplished 
in the heaters described later. With regard to the question of added 
moisture for optimum pressing conditions, see under “‘ Heating.”’ 
The advantages of decorticating consist in giving a somewhat hehter 
colored oil and at the same time removing the constituents which 
wear out the equipment. The literature persistently reports that 
the Italians produce a very superior medicinal grade of oul, which is 
practically tasteless, by pressing beans which have been decorticated 
or dehulled and carefully picked over by hand to remove the bits of 
adhering hull. On the other hand, the lack of sufficient fiber neces- 
182601 °—20——_2 
