SUGAR BOILING AND CRYSTALLIZATION-IN-MOTION 391 



from first principles what should be the elevation of the boiling point or the 

 indicated degree BrLx to conform to the saturation coefficients demanded for 

 these conditions. For each and every factory these will have to be deter- 

 mined by trial and error, and when once the}' have been determined the oper- 

 ation of pan boiling can be reduced to the execution of formal rules with 

 elimination of the personal error of the operator. When once the proper 

 factors for a few purities have been found, those for other purities can be 

 interpolated from the fonnulae already given in connection with the develop- 

 ment of the theory of sugar boiling. 



A special application of the brasmoscope lies in the determination of 

 the strike point of massecuites boiled blank. Such massecuites are usually 

 less than 50 polarization gravity purity, and for each purity the brasmoscope 

 indication at which exhausted molasses are afforded can be found. Since 

 the brasmoscope is graduated on a sugar scale, a higher indication \vi\\ be 

 sho\vn than is given in the table, this being due to the effect of the presence 

 of non- sugars of less molecular weight than cane sugar. The indications 

 corresponding to the different purities can only be fcund empirical^, but 

 when once one is determined the others can be calculated and definite 

 instructions given to the operator for each and every purity. 



Similarh' when boiling grained strikes, especiall}' those in the two and 

 three massecuites processes which are intended to afford waste molasses, 

 and which are boiled at unvarying purities, a constant Brix indication or 

 boiling point elevation at the striking point maybe determined, to which the 

 operator is tied. In this case it should be remembered that the indication 

 only gives the concentration of the mother liquor, and not that of the 

 whole mass. In this way a definite routine becomes established which, 

 when intelligently operated, tends to give regular and predetermined results 

 without the irregularities which too frequently occur when sugar boiling is 

 regarded as an art or craft. 



The Actual Processes employed. — The oldest scheme followed is one of 

 repeated boilings and extraction of sugar by a number of stages without 

 return of low products to process. In this sj'stem the syrup is concentrated 

 to a certain point, discharged from the pan and separated into crystals and 

 molasses. These first molasses may be regarded as a syrup of lower purity, 

 and the process repeated until eventually the purity is so much reduced 

 that the massecuite can be concentrated to a point where the mother liquor 

 has the composition of waste molasses. As conducted \nth a juice of high 

 purity the routine might be as foUows : — 



1. S\Tup is boiled to grain, discharged to receiver and dried at once, 

 giving first sugar and first molasses. 



2. The first molasses are boiled to grain, discharged to receiver and dried 

 at once, giving second sugar and second molasses. The sugar obtained in 

 this operation maj- be of 96 test, or if a little under it may be mixed with the 

 first sugar, which will probably be well ov^r 96 test. 



3. The second molasses are boiled blank and discharged into smaD 

 cans holding up to 500 lbs. each, allowed to cool and granulate for 3 to 4 

 days and then separated into third sugar and third molasses. The resulting 

 sugar will be from 88 to 90 test, and as such is not easily marketed. It 

 would then be remelted and returned to the syrup or used as seed grain in 

 the pans. In either case it appears eventually as first product. 



