REFRIGERATION OF FISH 541 



breaking off. Gutted fish are panned bellies downward, so that the 

 water may run out of the belly cavity. Round fish are packed 

 bellies up. Usually the fish are not panned in two layers, because a 

 two-layer cake is difficult to break, if a part of the cake is wanted, 

 without separating the whole. The bellies are left exposed, as 

 the appearance of the belly of a fish is often indicative of the 

 quality. Squid and butterfish are not arranged definitely in the 

 pans but are dumped in promiscuously. Shrimp are better scattered 

 thinly over the bottom of the pan, as otherwise they entrap so much 

 air as to freeze slowly. Sometimes mackerel and shad roes are 

 placed alone on the bottom of the pan, so that they can be wrapped 

 separately after they are frozen. The time required for panning 

 ranges from y 2 to 4 minutes for each pan, depending on the size 

 and style of arrangement of the fish and the skill of the operator. 

 For example, a skilled worker can fill a pan of Spanish mackerel, 

 small lake trout, or ciscoes in 1 to \y 2 minutes. It is generally 

 desirable to put as nearly as possible the same weight of fish in each 

 pan, but nowhere are the pans weighed as they are packed. When 

 the pans are filled, they are stacked on trucks, sometimes 8 or 10 

 deep. The pressure exerted on the fish in the bottom pans obviously 

 does the fish no good and by crushing and bruising may promote 

 autolysis. 



FREEZING IN THE SHARP FREEZER 

 DESIGN AND CONSTRUCTION 



Sharp freezers are usually small and several in number. The 

 sizes most commonly found have a capacity ranging from 15,000 to 

 40,000 pounds at a charge. Usually they are long, narrow rooms, 

 side by side, with doors at the ends. 



Small rooms usually are preferred to large ones, because such 

 rooms can be filled and left unmolested until the charge is frozen. 

 In large rooms the temperature is more stable because of the large 

 reserve of brine in the coils, but this advantage is offset by the 

 disadvantage of frequent opening and closing of doors to put in 

 and take out small lots of fish. 



The side-by-side arrangement reduces the necessity for heavy 

 insulation, except on outside walls, which should be covered with 6 

 or 8 inches of corkboard. It is always advisable to have storage 

 rooms, glazing rooms, or chill rooms, rather than warm rooms or 

 outside walls, adjacent to the sharp freezers. The same applies 

 to rooms above and below the sharp freezers. Anterooms also are 

 desirable to prevent excessive loss of cold air when the doors are 

 opened. Sometimes a narrow corridor is built, into which all of 

 the sharp freezers open. Often this is used as a glazing room. 



PIPING IN SHARP FREEZERS 



Along each side is a bank of refrigeration coils made of iy 2 or 

 2 inch iron pipe, arranged to make shelves on vertical centers of 6, 

 8, or 10 inches. Direct-expansion ammonia or calcium-chloride brine 

 from the refrigeration system circulates in these coils. If ammonia 

 is expanded directly into the coils the expansion valves preferably 



