612 



U. S. BUREAU OF FISHERIES 



joint. These pipes also connect by swivel joints with the brine- 

 feeding and discharge headers, so that the pans can be raised, one at 

 a time, turned up side down on the swivel joints, and the cakes 

 dumped. The pans are counterpoised by weights on pulleys. 



For loosening the cakes of frozen fillets in the pans a measured 

 quantity of warm calcium-chloride brine is admitted from a tank 

 into the wall spaces of the pan, forcing the cold brine out and back 

 into the refrigeration system. When a quantity of warm brine just 

 sufficient to displace the cold brine has been pumped in, a double- 

 throw valve is operated to circulate the warm brine in a circuit of 

 its own. Thus, the cakes are loosened and fall out. When the re- 



Fig. 45. — Cooke's method of freezing cakes of fillets. Machine in the foreground 

 closed and freezing. Machine in background opened and being discharged. Cour- 

 tesy, Atlantic Coast Fisheries Co. 



ceptacles are empty the valves are reversed, driving all of the warm 

 brine back into its tank, when, as the cold brine just fills the recep- 

 tacle wall spaces, a valve is thrown, which puts the receptacles 

 entirely in the cold-brine circuit again for freezing. An indicator 

 guides the operator in operating the valves so as to loosen the cakes 

 in the receptacles without mixing the hot and cold brine. The ex- 

 posed surfaces of the freezing molds are insulated with corkboard. 



While this apparatus is somewhat complicated and perhaps more 

 expensive to construct than some of the others, it undoubtedly pro- 

 duces frozen fish of excellent quality, frozen rapidly and without 

 contact with brine. With about one hour required, from the begin- 

 ning of freezing of one batch to the beginning of the next when the 

 brine is at 10° below zero, one battery of five double molds will freeze 



