THE EXTRACTION OF THE JUICE BY MILLS 203 



The Trash Turner. — The object of the trash turner is to direct the material 

 trom the top and the front rollers to the top and the back rollers. In per- 

 forming this function it acts in combination with the top roller, the lower por- 

 tion of which, in combination \\dth the trash turner, defines a passage through 



Fig. 100 



which the material is constrained to travel. A second dut\' of the trash 

 turner is that it acts as a scraper for the front roller. 



Evidently the setting of the trash turner is controlled by the quantity 

 of cane or rather the quantity of fibre which has to be passed in a unit of time. 

 An increase in the quantity of fibre necessitates a deeper passage, unless an 

 undue pressure is to be exerted by the bagasse. On the other hand, if the 

 bagasse is not compressed to a certain limit, it will lack the cohesion and 

 compactness necessary to make it " flow." 



In its passage over the bar, power is absorbed in friction, and this absorp- 

 tion increases as the width of the trash turner increases, or as the apical 

 angle of the mill becomes flatter. Various designs of mills intended to 



Fig. ioi 



Fig. 102 



diminish the width or to eliminate the trash turner have already been re- 

 ferred to. 



The proper curve for the trash turner has been the subject of much dis- 

 cussion. The following analysis was given by Bergmanns^° in 1889. 



