﻿FISH-SCRAP FERTILIZER INDUSTRY OF ATLANTIC COAST. 25 



automatic conveyor which supplies the fish to be cooked, while along 

 either side of the double row are placed other I rack's running to the 

 presses. 



Fish are dumped into the vats in quantities depending on the 

 capacity of the vats, usually 50 to 100 barrels, some water is added, 

 and the steam is turned on. They are cooked about 20 minutes, or a 

 sufficient length of time to cause them to break up easily, but not long 

 enough to disintegrate them entirely. The object of the cooking is 

 to break the oil cells or to bring about that condition which admits of 

 a more ready expressing of the oil. If the cooking is too prolonged 

 tli is is accomplished also, but the flesh is so thoroughly disintegrated 

 that it becomes a mush from which it is difficult to separate the oil. 

 The oil, water, and fine particles of flesh would squeeze out of the 

 presses together. 



PKESSING (OLD METHOD). 



The cooked fish are thrown from the vats into the curbs of the 

 presses by means of a modified shovel which retains the solid matter 

 and permits the water to run back into the vats. The curbs are 

 mounted on trucks and are brought alongside the vats by means of 

 the track, spoken of above, which parallels the rows of vats. The 

 curbs are generally tubs, whose cross section is a circle, constructed 

 of metal slats with an outward slant. The spaces between the slats 

 are of a suitable width to permit the water and oil to escape when the 

 pressure is applied, but to retain the solid matter. The spaces are of 

 the same width from top to bottom, since the outward slant of the 

 slats is compensated for by the increased width of the slats. The 

 bottom is hinged, and, while securely fastened, its lock is readily 

 manipulated and the bottom easily released. An iron shield is gen- 

 erally placed around the curb to protect the workmen from the jets 

 of water and oil which escape from the curb when pressure is applied. 



The curb, when it has received its charge of fish, is rolled back 

 beneath the press and the power is applied. In certain of the smaller 

 factories in the Beaufort region screw presses, manipulated by hand, 

 are still in use. Most of the other plants using the older, discon- 

 tinuous method of expressing the fish, however, are equipped with 

 hydraulic presses. 



The escaping water and oil is caught by the properly slanting 

 floor as is also that escaping from the curb during charging and 

 conveyed to the oil room for settling and further treatment. When 

 the maximum pressure has been applied and no more liquid is being 

 forced out the pressure is released, and the curb is rolled over an 

 opening in the floor for emptying. The bottom is then released and 

 swings downward, and the mass of fish scrap falls in a solid cake to 

 the floor below. The slanting sides of the curb are designed to 

 5781°— 13 4 



