FISH MEAL AND OIL 



477 



through the screen on each wheel. It is calculated that this press has a capacity of 

 from 4 to 12 tons per hour, depending on the type of material being pressed and 

 the amount of pressure desired to remove the moisture. 



It is possible to purchase cooker-press equipment built as a single unit. These 



{Courtesy P and L Welding and Machine Works) 

 Fig. 22-6. Continuous de-watering press for removing the water from fish meal. 



units are graded as to size by the amount of fish which can be handled per hour. 

 Butler (1949) gives the following estimates as to cost and size. 



"Although units of from 1- to 5-ton per hour capacity are available, the most common 

 continuous steam-cooker screw-press type of equipment usually installed has a raw- 

 material capacity of 10 tons per hour. Such an installation includes the grinders, con- 

 veyors, cooker, press, drier, the oil-settling tanks, sacking and meal-collecting equipment, 

 all motors, valves, and similar equipment, but not piping and wiring. The cost f.o.b. 

 manufacturer's plant for the 10-ton per hour plant is approximately $64,000 for the 

 steam-tube meal drier design and $54,000 for the direct-heat drier design. A recently 

 announced fish-scrap processing plant is designed to handle from 1 to 2 tons per hour 

 by the wet reduction process. Equipment is similar to that just listed except that no 

 drier is included. The price quoted is approximately $17,000. The press cake could be 

 handled in either a small direct-heat or steam drier, as for the 10-ton size plant, or in a 

 single dry-rendering type batch-drier described below. The latter drier unit, complete 

 with the grinders, conveyors, collecting and sacking assembly, and motors, would cost 

 approximately $22,000. If the fish scrap is wet-processed prior to the batch-drying by this 

 method, the capacity of the combined equipment may be estimated at about 24 tons of 

 raw fish scrap per 12-hour day." 



Drying the Fish Meal. When the pressed material leaves the presses, it is con- 

 veyed to a grinder where it is broken up into small pieces. It then passes into 

 one of several types of drying equipment where the moisture is reduced to 6 to 8 

 per cent. 



