598 



SUGAR-BEET 



SUGAR-BEET 



At all times it is very desirable to load the kiln 

 with nothing but uniform sizes of rock. No rock 

 smaller than one-half the size of a man's fist should 

 be put into the kiln, as the small pieces will tend 

 to stop the draft ; and no pieces much larger 

 than the size of the two fists should be used, as the 

 very large rocks will not be burned through entirely. 

 The top of the rock should alwa"s be four to six 



Fig. 825. backs of beet-sugar ready for shipment. 



feet below the gas pipe in the kiln. The coke should 

 be of open grain, and at the same time be fairly 

 compact, for then it will hold its heat during the 

 required time to give the best results. The coke 

 should be free from sulfur, as there is a possibility 

 of sulfuretted hydrogen being generated, which, 

 when carried into the carbonatation tanks, might do 

 considerable harm. 



The importance of care in addition of lime to the 

 ' juices cannot be overestimated, and, if the liming 

 is not done according to the various rules that have 

 been applied only after years of experience, the 

 succeeding operations will prove failures and the 

 iinal product will be of little value as a marketable 

 commodity. The changes which take place during 

 the carbonatation are both mechanical and chemical. 

 In the chemical nature, the lime forms compounds 

 with the sugar and the impurities present in the 

 juice. Some of these compounds are of complex 

 combination, while others are very simple in their 

 composition. 



The gas. — The gas which is produced in the kiln 

 and pumped into the tanks of this first carbonatation 

 station has a great afiinity for the lime, breaking 

 up the compound it forms with the sugar and form- 

 ing an insoluble lime carbonate, thus setting the 

 sugar free and leaving it in solution in the juice. 

 The gas is pumped into the tanks through pipes 

 which extend to the bottom of the tanks and are 

 there divided into three sections. From each of 

 these sections it passes through the perforations in 

 the pipes and bubbles upward through the juice. 

 The moment the gas comes in contact with the juice 

 it causes a change to take place ; there is a thicken- 

 ing of the juice in proportion to the degree of con- 

 centration and the amount of sugar present. Dur- 

 ing this period there is no precipitation, but rather 

 a gelatinous consistency, which decreases with the 

 length of time that the juice is acted on by the gas. 

 At the beginning of the carbonatation there is ex- 



tireme frothing, which gradually diminishes and 

 finally ceases altogether. At this point the precipi- 

 tate forms, settling rapidly and easily, and is read- 

 ily filtered. The juice is then ready for filtration, 

 and is pumped through the filter presses, leaving 

 behind the heavy deposit, while the translucent yel- 

 lowish liquid passes on into the second carbonatation 

 tanks. 



The filter. — The filter presses consist of a series 

 of iron frames, every alternate one of which is 

 hollow. The solid frames are covered with heavy 

 duck cloth, which allows the juice to pass through 

 but prevents the passage of the heavy deposit 

 formed in the tanks. This deposit is called lime- 

 cake and is an excellent material for fertilizing 

 the farm lands. After the presses have been 

 filled with lime-cake, they are washed, emptied of 

 the cake and made ready for filtering more juice. 

 The presses are screwed together under great pres- 

 sure in order to prevent the possibility of any loss 

 due to leaky joints in the press. 



Second carbonatation. — Prom the presses of the 

 first carbonatation the juice passes to the second 

 carbonatation station to be treated as before, with 

 the exception that only a small quantity of lime is 

 added and the time of carbonatation is not so long. 

 The action of the lime and the introduction of the 

 gas at this station produce a clear liquid of bright 

 amber color which filters with more ease than at 

 the first station, and is then ready for the treat- 

 ment with sulfur gas. As the juice leaves the first 

 presses it has a high alkalinity, which must be 

 reduced before it is ready for boiling. The greatest 

 epurating action has been found to be after the 

 lime has been added twice to the juice and the 

 juice carbonated after each addition. Usually .25 

 per cent to .50 per cent of lime is used in the 

 second carbonatation. 



In all operations in the process of making the 

 sugar the juices must be kept hot and at specified 

 temperatures. The cake formed at the second 

 presses is softer, whiter and more chalky than that 

 of the first presses, but at the same time it is 

 inferior for agricultural purposes. 



Sulfuring. — Leaving the second presses, the 

 juices are pumped to the sulfur station to be 

 further treated before the first evaporation. Here 

 the juices are brought into contact with the gas 

 secured by passing air over burning sulfur. This 

 gas is carried into the tanks in the same way as in 

 the tanks of the first and second stations. The 

 action of this gas on the coloring substances that 

 are in the beet juices varies, destroying only in 

 part the coloring matter present. While sulfuring 

 has hardly any effect on the purity of the juices, it 

 gives a sparkle and has a brightening influence, 

 and causes the juices to crystallize better. It is also 

 important to note that the sulfurous acid decom- 

 poses the organic lime salts, while the carbonic 

 acid does not. 



Evaporating. — After sulfuring, the juices are 

 filtered through special filter presses, or mechanical 

 filters, and are then ready for the evaporators, in 

 which they are boiled under a vacuum in order to 

 concentrate them without the danger of destroying 



