400 



FARMERS' RfiGlSTER. 



[No. 7 



Concentration operates by the intervention of 

 fire, which reiluces the waier to the stale of va- 

 por; and as the tension of vapor is reiTulated by 

 the temperature, it follo\vs that, to produce the 

 ■qnici<est pos>ihle evaporation, under the atmos- 

 pheric pressure, it will be necessary to ex|)ose it to 

 the highest teirijierature that it can lake under this 

 pressure, which is that, of ebullition. 



There are oilier n)elhods of producinj? concen- 

 'tration. Achard, for instance, by steam, (not 

 hiiih pressure, J actinj? on tiie boiler which con- 

 tained the juice to be evaporated. This he eli'ect- 

 -ed without ebullition, but very slowly. In Euirland 

 syrups are often evaporated by means of sieam ; 

 but there it is so hifrbly compressed ihai the liquor 

 enters into ebullition as if it were exposed to a na- 

 ked fire. All these means of evaporation are more 

 or less complicated, and on that account rather de- 

 viate from the common routine of atrpicultural op- 

 erations. The author therefire confines himself 

 to the most simple mode of evaporation f()r con- 

 centrating the juice of the beet root. The great 

 problem is, 



"To exhibit the simplest apparatus for concen- 

 trating the juice in the shortest possible space of 

 time, and with the least alteration in the quality."* 



§ 1. Of Evaporating /Apparatus, or Boilers for 

 Concentration. 



Boilers of cnpperare thought to be the most suit- 

 able li)r this purpose. It has been proved both by 

 theorv and practice that the vapori?;ation of liquids 

 is best effected in wide open vessels. It is then 

 important that the evaporatmirsurlaces should be 

 -as large as possible, and exposed to the direct ac- 

 tion of the tire. But herein a difficulty presents 

 itself, which is this : — 



The beet root juice will suffer by concentration 

 a reduction nearly equal to four-fifihs or five-sixths 

 of its volume, according to its richness, and this 

 reduction ouirht to take place in a very short time, 

 wliich, of course, is only to be effected by a fierce 

 fire. The irreat difficulty in this case is to prevent 

 thesuirar from burmiii''. But the better way per- 

 haps will be to give a brief analysis of the several 

 modes actually in use. 



I. jfcharcfs Plan (f Concentratinn. 



This chemist recommended from experience the 

 concentration by steam, for which purpose he had 

 two boilers (ilaced for one delineating boiler. These 

 were charired only about six inches deep, conse- 

 quently the process is very slow, and, in the au- 

 thor's opinion, by no means advantageous to fol- 

 low. 



2. Plan adopted at Chatillon-sur- Seine. 



Here the concentration is effected in boilers 

 equal in capacity to those of defecation, thus each 

 defecating boiler has its evaporating boiler. The 

 process of concentration requires ten or twelve 

 hours to bring the juice to 22 areometrical degrees 

 boiling. This is a very imperfect systetn. 



3. M. ChaptaVs Plan of Concentration. 

 This chemist employs one evaporating boiler for 



* In the process of boiling, f^reat improvements have 

 recently been made in France, steam beinjj now g;en- 

 erally employeil for that purpose in the several sugar 

 estdliiiishnieiits. 



one of defecation, and this boiler, 15 inches deep? 

 receives all the juice of one operation. The sur- 

 fice of I his boiler is calculated to contain about 

 8G10 Enu'lish sijuare inches, (SoS^ square decime- 

 tres^ capable of evaporating per hour as many 

 killoiri'ammes of water (555^ killo n: r2211bs.3 

 M. Chaptal concentrates the syrup to 28° boiling, 

 which corresponds with 32^ cold. To obiain this 

 result it was neces-sary to reduce the body nearly 

 to a sixih, which would require three or t()ur hours, 

 a period considered to be too long. M. Dubrun- 

 ti^iut therefijre does not advise a single boiler tor 

 ihis oj aeration. 



4. Plan nf Concentration generally in Use. 



This method consists in the adoption of two 

 evaporating boilers, jbr one of defecation. All 

 three have boitotas of the same dimensions; and 

 as the two former are capable of receiving all the 

 juice furnished by one defecation, they are made 

 rather more than half the height of ihe' latter. 

 'I'lms admitting that the one contained 2000 hires, 

 (Id cubic feetjj each of the others world contain 

 rather more than 1000 litres, (^5 cubic feet). 

 This plan is practised iit many of the mannfacto- 

 ries. Siill some are of opinion that it is not the 

 most advantageous to adopt. 



5. M. Crespefs Plan of Concentration. 



Each boiler of concentration is 2m. 32 Cabout 91 

 inches) lonir, nnd Im.OG (39inclresJ wide, and pre- 

 sents a surface of 3000 square inches. There are 

 six of these for one of defincalion. An evaporaiion 

 takes place during the defe-cation of about an 18th 

 part of the mass.* About 280 to 300 litres (62 to 

 67 callonsj are poured into each concentrating 

 boiler, which is nearly four inches deep. The 

 juice is kepi boiling till it had reached 31° of 

 Heaume. This operation will require five hours. 

 The ISOO litres (400iral|ons or so) contained in the 

 si.K concentrating boilers will be reiluced to 220 or 

 240 litres (50 or 54 gallons) of syrup, according to 

 the richness of the beet foots in saccharine matter. 



The above is !VI. Crespel's own account, but 

 since it was written he has made many improve- 

 ments, and particulaily in bis evaporatinu; appara- 

 tus, which is conjposed of" two rows (batteries) of 

 six boilers each, fomiing a set for each of the two 

 defecating boilers v»'ith which they are intended lo 

 act. 



Each of" these boilers may be about four ftnet in 

 diameter by one foot in hei<rht. The following is 

 the mode of using them: The chargeof one of the 

 defecating boilers being drawn ofi clear, is distri- 

 buted by equal portions over the six boilers which 

 compose one of the batteries. They are then sub- 

 mitted to a brisk evaporation till the juice has ac- 

 quired a density of 20° or nearly so. The con- 

 tents of the six boilers are then united in one, to 

 be clarified, which process will be described here- 

 after. The concentration thus advanced but lo 

 20° (areometrical,) does not expose the juice tO' 

 the risk accruiiiir from too thin a body.t 



This JVl. Dubrunfaut thinks the best plan he had 

 hitherto seen adopted, although in his opinion it 



* This reduction arises not so much from evapora- 

 tion as from the scum and froth removed during the 

 defecatinsc process. 



f M. Crespej, I am informed, has materially altered 

 his plan since this wa^ written. 



