278 



CHAPTER XIV 



tank are a number of deflecting plates by means of which the juice is made 

 to change its direction. During its passage the juice is continually deposit- 

 ing its suspended solids. 



Flotation of the scums has also been applied to continuous setthng, as 

 for example in Harvey and Scard's patent 6093 of 1899. It also forms a 

 part of Rillieux's second patent on multiple effect evaporation. In the 

 Hatton continuous defecator, Fig. 163a, the cold limed juice enters the 

 vessel by the pipe C through the valve B and header A . As the vessel fills, 

 juice flows into the interior vessel D, which is closed at the bottom, and thence 



Fig. 163a 



upwards through the pipe C, and away by the pipe F to the clear juice conduit. 

 The scums collect on the surface of the juice and are removed from time to 

 time. Heavier particles which settle are distributed by occasional rotation 

 of the scraper, and are then intended to be carried upwards to join the 

 floating layer. The temperature is controlled b}^ a thermostat, consisting of 

 a tube (shown below D) filled with water, the expansion of which acting on 

 the diaphragm fixed at the right hand side of the defecator (as shown in 

 the figure) operates the balanced valve above it. 



The Williamson continuous defecator (U.S. patent 1,317,607) has been 

 installed and successfully operated in one or two American refineries on 



