CANE SUGAR. 



FIG. 210. 



are also produced in quantity where a large local demand exists as in Natal 

 and South American countries. The special methods of clarification have 

 been described in Chapter XTII. ; in curing these sugars water and then steam 

 are used. 



In many factories specializing in 

 these sugars the writer has seen the 

 water thrown into the basket from a 

 saucepan or other simple receptacle. A 

 more efficient scheme is shown in Fig. 

 210 \ the water leaves the nozzle in a 

 fine spray and is evenly distributed 

 over the sugar; the pipe is jointed at b 

 so that the part be may be swung out 

 of the basket during charging. After 

 the water has been used, steam is admitted to the interior of the basket. In 

 Mauritius steam at 60 Ibs. per square inch pressure is led to the basket from 

 the main steam pipe by means of a flexible hose ; the action of the steam is 

 two-fold ; the elevation of temperature makes the molasses more limpid, and 

 condensation of the steam and water already present dissolves out some crystal 

 sugar. Superheated dry steam does not dissolve sugar, and hot air would have the 

 the same effect, but some solution and temporary loss of sugar is necessary so as 

 to entirely remove the film of molasses and to obtain a really high class article ; 

 actually a massecuite which would give say 64 per cent, of raw sugar will 

 give 50 per cent, of plantation refined. The sugar thus obtained remains in 

 the basket as a hard compact mass and before bagging has to pass through a 

 sugar breaker or mixer; dry sugar ' polarizing 99-7 ' at 28 C. may be obtained 

 with this scheme. 



Classification of Syrups. When sugars are washed the last run- 

 nings are of high purity and should be collected separately. One method 

 consists of the use of two gutters as shown in Fig. 211 ; when the molasses 



^ ^ proper is running it is 



directed to gutter b, the 

 spout c being in the position 

 shown ; when water or 

 steam are being used the 

 spout c is raised so as to 

 occupy the position shown 

 by the dotted lines and the 

 runnings pass into the 

 gutter a. Owing to the 

 slowness with which mo- 



FIG. 211. 

 lasses flow, only a very partial separation occurs. 



280 



