348 



MARINE PRODUCTS OF COMMERCE 



"Blizzard" and in York air-blast freezers. The "tunnel" will hold 2 trucks, each 

 loaded with approximately 1,000 pounds of fish. 



The temperature of the air used in freezing fish by the air-blast system is 

 usually between -10 and - 20° F (-23.3 and - 28.9° C) although lower 

 temperatures are sometimes used. The air velocity employed usually varies be- 

 tween 500 and 2,000 feet per minute; the greater the velocity, the more rapid 

 the freezing (Fig. 16-7). 



The Kolbe "Diving Bell" Freezer. R. E. Kolbe (1925) has developed 2 types of 

 machines for freezing fish. The first, which is known as the "diving bell" system, 



Fig. 16-8. Lowering a frame 

 of Kolbe "Diving bell pans" filled 

 with fish into the cold brine. 



{Courtesy Union Fish Co.) 



freezes fish in shallow metal pans fitted with telescopic covers. This is still in use. 

 A number of these pans are placed in a frame and then lowered in a brine tank 

 (Fig. 16-8). The brine is prevented from entering the pans by the entrapped air 

 in the covers of the cans. 



Kolbe's Floating Pan System. In 1927 Kolbe received a patent on a system of 

 freezing individual fish or fillets in pans floating on brine in a trough of re- 

 frigerated brine. The pans are circular and about 20 inches in diameter and 3 

 inches deep. The usual form of Kolbe's apparatus consists of a shallow insulated 

 brine tank with longitudinal baflles, alternately fitting close to one end and lack- 

 ing about 2 feet of meeting the opposite end of the tank. Brine entering one end 

 flows through this series of troughs formed by the baffles and carries the pans 

 containing a single layer of fillets, steaks, or small fish. The system of troughs is 

 so arranged that the pans start and complete their trip at the same point. The 



