\ Mr. S. N. Gundu ' ~ao presented the following paper.

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1 r I 464 CHEMICAL ANALYSIS AND FACTORY REPORTING 9. Prinsen Geerligs, H.C., " Cane Sugar and its Manufacture " McClery, M.C Z.S.J. July Behne, E.R. Queensland Proceedings, VI, Ann. Conf Douwes Dekker, K Z.S.J. May, 122.,+ 13. Farnell. "Principles pf Sugar Teclznology " by P. Honig Birkett. L.S *, studies in the Exhaustion of Cane Molasses. Sugar Nov Douwes Dekkef, 5. Judging soiling House Work. Proc. VZZZ Congress of I.S.S.C.T. 677., I 16. Gundu Rao and Kulkarni Exhaustibi!ity of molasses from drought affected cane. Proc. 23rd Any. Con. S.T.A. (India) Part \ Mr. S. N. Gundu ' ~ao presented the following paper. Paper 1 FURTHER STUDIES ON BOILING HOUSE EFFICIENCY INDICATORS S. N. GUNDU RAO and H. G. KULKARNI 1 Ravalgaon Sugar Farm Ltd, Ravalgaon, India It is now recognised that B.H.E.N., B.H.P. and Winter Rendement are similar in form and derivatiod and have the same drawback of dependence on juice purity. The Java Experiment Station (I) did not favour the Winter Rendement as a comparison figure due to this drawback and evolved the " Old Comparison figure of the Java Experiment Station ", the so-called " Technical Result ". This comparison figure is the first to recognise the importance of referring the molasses Ioss to a standard juice purity of 85, and is the forerunner of the Reduced Boiling House Recovery. Noel Deerr used the principle involved in the " Technical Result " of Java Experiment Station in arriving at a recovery figure at 85 juice purity. But in this procedure of arriving at the R.B.H.R., a wrong concept of virtual purity was involved and hence the resulting figure favoured factories having low purity juices and handicapped factories having high purity juices. This has been overcome by the procedure evolved by Gundu Rao (2) and we have-now a correct method of finding the actual recovery at 85 juice purity. The old comparison figure of the Java Experiment Station was discarded in favour of the New Comparison Figure of the Java Experiment Station. In this figure, instead af the ratio of actual recovery to ideal recovery as in Winter Rendement, the difference between the ideal recovery and the actual recovery I

2 S. N. GUNDU RXO, H. G. KULICARNI used to arrive at the comparison figure. his was a decided improvement the Winter Rendement as the influence of mixed juice purity in a range of units (74 to 94) was reduced from 4.45 in the case of B.H.P. to 2.87 in the case of New Comparison Figure as shown by Kripashanltar (3). Even so, the influence of juice purity thus remained. This drawback in the New Comparison Figure could be overcome, if the actual and the basic recoveries are referred to a standard fixed juice purity 85. The improved comparison figure, which is free from the drawbacks of the Winter Rendement and the new comparison figure of Java would be : 100-(Basic Recovery at 85-Actual Recovery at 85) This new figure thus combines the essential principles sought to be applied in,jhe Old and New Comparison Figures of the Java Experiment Station and tke Reduced Boiling House Recovery concept of Noel Deerr. In this formula, the Basic Recovery at 85 would be calculated by the usual formula, taking J as 85 'and &I as The Actual Recovery at 85 would be the R.B.H.R. as obtained by Gundu Rao's formula. So long as the quantity factor only is considered, the R.B.H.R. (Gundu Rao) can be directly used for international comparison. However, if any efficiency figure is required, the modified'java procedure would, be better. INTRODUCING THE QUALITY FACTOR The next step would be to make this efficiency formula correct in respect ]of the quality of non-sugars. Considering the difficulties involved in asse"ssing the influence of non-sugar components, individually and in the presence of each other, on the recovery and the wide variation of these non-sugars, with soil and climate, it would not be in the immediate future that quality factors applicable to different countries are found. Even assuming that such factors are found out, the best way of allowing for the variation in the quality of non-sugars and their influence on exhaustibility (or recovery) is to arrive at the target purity of final molasses corresponding to the non-sugar composition. It is obvious that the envisaged quality correction should be incorporated into a formula which is quantitatively correct. As we have established the Modified lava Comparison Figures quantitatively correct, we proceed to correct this figure for quality as follows : When the target purity of final molasses is fixed for the particular non-sugar composition, the basic recovery 85, in the new formula, which call now be called the target iecovery, could be calculated by the usual procedure by using the target purity of molasses in place of the fixed figure of The new efficiency figure which is thus corrected for quality and whicll we propose to call " International Comparison Figure " would be : 100-(Target Rewvery at 85 Purity-Actual Recovery at 85 Purity)

3 I 466 CHEMICAL ANALYS~S AND FACTORY REPORTING This can be further reduced as follows : International Comparison Figure = 100-(Target Recovery 85-Reduced Recovery 85) = 100-Target Recovery 85 +Reduced Recovery 85 But 100-Target Recovery 85=Target Loss. Therefore, International Comparison Figure =Reduced Recovery 85fTarget Loss. The target loss at,vari,bus target purities of molasses is given in Table I. TABLE I SHOWING (i) TARGET RECOVERY, (ii) TARGET LOSS and(iii) QUALITY :CORRECT~ON FOR R.B.H.R. Target Purity Basic Recovery Target Quality Correction of Molasses for R.B.H.R. This new efficiency figure is superior to the figure of B.H.P. previously suggested by Gundu Rao. This is because, when varying target purities are used in calculating the Basic Boiling House Recovery at 85 juice purity, it will influence the final figure in the same manner as varying juice purities influenced the Winter Rendement or B.H.P. In this connection, it is pointed out that, when target purities begin to be considered in B.H.P. or B.H.E.N.or Winter Rendement, apart from the accepted influence of varying juice purity, the influence of varying target purity further complicates the accuracy of the result. The influence of juice purity is eliminated in the new figure by taking 85 standard purity and the influence of variation in target purity, which, however, is smaller, is further reduced by taking the difference in recoveries and not the ratios. From all points of view, therefore, the best efficiency figure is the "International Comparison Figure" now suggested. It is further pointed out that till such time as it becomes possible to" fix target purities an the basis of non-sugar composition, the constant figure of will continue to be the molasses purity figure in calculating the Basic Recovery in the "International Comparison Figure". CORRECTING R.B.H.R. FOR QUALITY It has already been mentioned, that the Reduced Boiling House Recovery Figure on a quantitative basis can be directly used for efficiency comparisons, but with the quality factor being intraduced, it becomes necessary to correct the

4 S.N. GUNDU RAO, M. G. KULKARNI re for quality differences, if direct comparison is to be made of the recovery res. This can be done by adding to the R.B.H.R. obtained a figure which to the difference between the target recoveries. In order to be able ch both the quantity and quality of non-sugars have been considered. REFERENCES DISCUSSION Dr. Douwes Dekker drew attention to the last paragraph of Dr. Honig's paper. He said that he was amazed that Dr. Honig should recommend a factory control based on apparent analysis. The System of Factory Control aimed at control on a sucrose basis and the proposal to revert to pol for control purposes was revolutionary. Why, he asked. further, should 'determination of Boiling House Efficiency be based on the purity of the syrup. Whilst this.procedure would eliminate the problem of how to deal with clarification, it would have the effect Mr. Gundu Rao agreed with Dr. Douwes Dekker. He felt that pol did not provide a that the measurement of Boiling House Efficiency should start with the mixed juice. If the calculations were based on clzrified juice or syrup, then it would be necessary to take account 'of the method of clarification although this would not be involved directly in the efficiency results. 'He believed that the clarification process should be incorporated in the stages over which Boiling House Efficiency was measured. ' Dr. Douwes Dekker commented that, perhaps, Dr. Honig proposed that clarificatio~l.should not be included and that Boiling House Efficiency should be applied only to the results {of actual sugar boiling. i Mr. Gundu Rao considered that the formula proposed by Dr. Honig was similar to the Winter formula with a target purity of final molasses. As such, it had the disadvantage of being a ratio, 'which was unsatisfactory for varying purities of original material. The adoption of various I ' :target purities for final molasses would complicate the issue further.. Mr. Kelly expressed the opinion that, for satisfactory control, it was necessary to concentrate on sucrose figures. Variations in the quantity and nature of the reducing sugars made pol figures,unreliable. He was concerned about the target purity of molasses which he thought must be based on sucrose. Dr. Honig's formula was statistically satisfactory but could not be reconciled with the theoretical approach. He cited the foimula devised in Taiwan wherein the target purity

5 I 468 CHEMICAL ANALYSIS AND FACTORY REPORTING as a function of the dextrose in the reducing sugar's and the conductivity ash measured as potassium chloride. He hoped that any formula adopted for target purity of molasses would be in a form which would satisfy both theory and practice.. Dr. Douwes Dekker emphasised that boiling house results represented the comparison of certain actual losses with theoretical or standard allowances. The losses were undetermined loss, loss in filter cake and molasses loss. would it not be better to evaluate and judge each of I Ih6se separately?