CASTOR-OIL INDUSTRY. 



19 



at the middle, and 0.025 inch at the discharge end, all bound together 

 by massive clamping bars. A horizontal screw rotating on the axis 

 of the cage carries the charge of oilseed forward and discharges it 

 at the other end of the cage over a cone, which may be moved in or 

 out, according as greater or less pressures are sought. The charge of 

 oil-bearing material is introduced through a hopper into the cage or 

 barrel and the slowly rotating worm engages it and carries it forward. 

 As the charge reaches the small aperture around the cone it encoun- 

 ters more resistance, which operates to build up pressures within the 

 barrel. These pressures are regulated by varying the size of the 

 aperture between the cone and the walls of the barrel. The farther 

 the cone is moved into the barrel, the smaller is the aperture through 

 which the cake may be discharged. Inasmuch as the screw moves 

 forward at a constant rate and thus delivers a continuous quantit} r 

 of material to the 

 barrel, it follows that 

 the oil yield is readily 

 controlled by simply 

 adjusting the cone and 

 varying the size of the 

 discharging aperture. 

 For ordinary materials 

 these expellers can be 

 adjusted to yield cakes 

 containing as low as 5.5 

 per cent of oil. 



These machines are 

 very generally used for 

 peanut and copra crush- 

 ing and for many other oleaginous materials, all of which, however, 

 must have such fiber content as to present sufficiently effective binding 

 properties to prevent squirting of the meats through the interstices 

 of the bars. There is, of course, great wear of the parts, but since 

 these are standardized they can readily be supplied. It has been 

 stated that with properly cleaned material and with right care of the 

 machine the upkeep is no greater than the cost of the cloth in plate 

 presses. An average for more than seven prewar years shows the 

 upkeep to have been about SI 00 for each machine per annum. 



Figure 12 represents a battery of such machines set up somewhat 

 as they appear in good factory installation. Manifestly, the small 

 labor charge attendant on their operation is much in their favor, 

 together with the cleanliness and mechanical simplicity of their 

 action. One man can operate the whole battery, and even more. 



Fig. 11. — A cage carriage . 



