608 



U. S. BUREAU OF FISHERIES 



bottom of the can brine must be in contact. If the depth of the lid 

 is calculated for this condition in the top can, the others also will be 

 bathed on the bottom. Of course, a leak, even a tiny one, in the lid, 

 would allow the air to escape and brine would strike the fish. 



Kolbe has also devised re an ingenious method of freezing fillets 

 and fish individually. The apparatus, consisting of a shallow, insu- 

 lated tank, is fitted with galvanized sheet-iron partition baffles that 

 divide the tank into a labyrinth or devious channel returning to a 

 point near which it starts. Cold brine is pumped in and flows 

 through this circuitous channel at a moderate rate of speed. 



The fillets or fish are put in circular pans or boats made of gal- 

 vanized sheet iron, 18 inches in diameter and 3 inches deep. These 



Fig. 43. — Kolbe's method for fillets and small fish. The maze tank, uncovered to 

 show arrangement of baffles. Courtesy, Kolbe Fish Co. 



boats are laid in the floating brine, whereupon they follow the stream 

 through the channel, returning to a point near the starting point, 

 The same operator loads the cans, starts them on their way, and re- 

 ceives them on their return. 



At the completion of freezing the pans are removed, drained for 

 a moment, inverted, and knocked against the wooden table. The 

 tank is heavily insulated and has an insulated cover. The fillets 

 or individual fish fall out and the pan is ready for repacking. The 

 pans, being circular, do not jam in their course through the freezer, 

 and the freezer may be filled to capacity with them without inter- 

 ference. Fillets of blue pike freeze in from 20 to 30 minutes with 

 brine at about zero. Whitefish, being thicker, freeze in about 3 

 hours at this temperature. More rapid freezing can be obtained, 

 of course, in brine of lower temperature. 



79 Patent pending (December, 1925.) 



