UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAN. 39 



RENDERING APPARATUS. 



The equipment and operation of the large-scale rendering stations 

 now in successful operation have been described compositely in 

 foregoing paragraphs. A strictly conservative procedure would be 

 to adhere to demonstrated methods. However, since these methods 

 once were in universal use on the Atlantic coast and now have been 

 discarded almost universally to make way for new methods, a dis- 

 cussion of new methods, and even a recommendation of their cautious 

 adoption may be justified. 



The only process which has been applied with any success to the 

 rendering of this class of material on the Pacific coast, it has been 

 shown, is discontinuous. The apparatus required by this process 

 may be installed and operated in small units, necessitating a multi- 

 plication of the labor involved, or in large units, involving more 

 labor than the small units, of course, but not proportionately. Since 

 the material to be treated is secured in irregular and uncertain 

 amounts, a number of small units would afford more of the required 

 elasticity than an equivalent number of large units, but the cost of 

 labor required to operate such a number of small units soon would 

 become prohibitive. So, by nature, this apparatus offers serious 

 objections to its adoption in the large-capacity plants. 



The continuous and automatic machines for cooking, pressing, and 

 drying in use in the fish-rendering industry of the Atlantic coast 

 should lend themselves readily to adaptation to that industry on the 

 Pacific coast. These make possible the cooking, pressing, drying, 

 and intermediate handling of the fish entirely by machinery, with a 

 high efficiency and minimum expenditure of labor. The unloading 

 is done by elevators, which deposit the fish in storage bins, from 

 which they are fed into continuous steam cookers, long tubular cham- 

 bers through which the fish are moved by a rotating screw, being 

 played upon by jets of steam. Thence they are transported by con- 

 veyors, into which they are fed, to the power presses. These are steel- 

 slatted cones, through which the cooked fish are forced by a rotating 

 screw. As they move toward, and before they can pass out of, the 

 small end of the cone, they are squeezed into a very small compass. 

 This pressure rids them of the greater portion of their water and 

 oil. From the press they are conveyed, again entirely automatically, 

 into a direct-heat, rotary, hot-air drier. 



A plant designed for the treatment of 100 tons of cannery waste 

 per day and equipped with the automatic machinery complete would 

 cost about $35,000. This estimate x is based on the following items. 



1 The itemized statement of the cost of equipment and plant is made possible through 

 the courtesy of Mr. Philip Renneburg and Mr. P. Burgess, of Baltimore, Md. 



