CASEIN : ITS OKIGIN, PREPARATION AND PROPERTIES. 7 



Steam, or even hot water, can also be used for heating the 

 pans, and a steam pan of this character is illustrated in Fig. 

 2. The advantage in this case is that the heating surface 

 exposed to the steam is very large and therefore utilises the 

 heat fully. A very useful form of pan is the " duplicator " 

 (Fig. 3), made by A. Pfanhauser of Vienna, for casein, jam 

 boiling and for evaporating or cooling milk, etc. It consists 

 of two copper pans (of one-eighth to one-twelfth inch sheet 

 copper), mounted in an iron frame, so that the whole can be 

 tilted. The trunnions are hollow, to admit steam on the one 

 side and cold water on the other, branches from the trunnions 



FIG. 8. " Duplicator " Pan for Casein. 



entering the jacket space and terminating in perforated pipes 

 to ensure more perfect distribution of heat. D represents the 

 steam valve, W the water tap, and C the discharge tap. The 

 cold water runs away through the overflow, Ue. 



No special boiler is needed for generating the necessary 

 steam, no high steam pressure being required. A very con- 

 venient steam generator for this purpose is supplied by Pfan- 

 hauser (Fig. 4). Where water can be drawn from the mains, 

 the boiler is filled through the pipe (a), but in other cases 

 a tundish must be used. The steam leaves through the pipe 

 (B), which can be fitted with several branch cocks, as shown 



