UTILIZATION OF THE FISH WASTE OF THE PACIFIC OCEAN. 31 



chamber of brickwork. Hot gases from crude petroleum burners are 

 admitted to the chamber surrounding the cylinder and are drawn 

 thence into the cylinder through apertures constructed at intervals in 

 the walls. The scrap to be dried is admitted at the hot end of the 

 cylinder and removed at the cool end, thus traveling with the current 

 of air. From the cylinder it drops into an elevator and is carried 

 therein directly to the bagging room. The current of gases through 

 the drier is maintained by a rotary fan situated behind the drier. 

 By means of this the gases drawn from the drier are forced through 

 a chamber where they are washed free from suspended particles by 

 means of a water spray. Thence they are driven through the fire box 

 beneath the factory boilers. In this manner odors arising from the 

 hot-air drier, and constituting, perhaps, the only objection to its use, 

 are completely destroyed. 



In the fertilizer plants of the Pacific coast the steam drier is em- 

 ployed most commonly, owing possibly to the simplicity of its in- 

 stallation and operation and to the fact that of all the driers it is 

 most readily available in the desired capacities. It is not intended 

 that the idea shall be conveyed by this statement that the steam drier 

 inherently is more simpry installed and operated. Such is not 

 believed to be the case. But at present the hot-air driers advertised 

 for sale and actually in use are large in both size and capacity and 

 are unfit for the treatment of small amounts of material. The manu- 

 facturers have failed to meet, or perhaps to create, a demand 

 for driers cf small capacity, and for that reason the steam drier is 

 in most common use. An additional advantage possessed by the 

 steam drier is its simplicity of regulation. Overheating being im- 

 possible, it remains only to admit the steam and wait for the charge 

 to dry. It can not be regarded as the most efficient or as the most 

 economical except in cases where exhaust steam is employed. 



The type of steam drier found in use in drying scrap from salmon 

 waste usually is a horizontal cylinder provided with steam coils in- 

 side, or encircled by a steam jacket. For stirring, the cylinder is 

 equipped with paddles revolving in it, or the cylinder itself is 

 rotated on a horizontal axis. 



A third type of drier, recently installed in a certain manufactory, 

 is unique in that it makes use of the waste heat from the fires be- 

 neath the factory boilers. As this drier was designed by the operator 

 from ideas suggested by his experience, and is not advertised for sale 

 by the manufacturers of driers, the writer does not feel justified 

 in publishing here the details of its construction. It should suffice 

 to say that the drier is reported as being quite efficient and satis- 

 factory, and the scrap coming from it is of a very high quality. Its 

 lack of importance as a type is more than made up by its value 

 as an illustration of what is possible in the enhancement of economy 

 in a fish-rendering plant. 



