Annual Report 1961 - BEEP

and well mixed. A one-litre aliquot portion istaken, 2 to 4 g Celite filter aid arc added andstirred in, and the mixture filtered in a Buchnerfunnel through a tared filter paper. The latteris then washed well with distilled water and driedto constant weight in an oven at 105°C. Mudsolids per cent in the original amount of feedor cake is then calculated from the increase inweight of the filter paper after deduction ofthe amount of filter aid added.(b)FibreFilter feed (50 g) or cake (20 g) is weighedand washed over a tared 200 mesh sieve untilthe water runs clear. Excess water is drainedoff and the sieve and contents dried in an ovenat 105°C to constant weight. Fibre per cent IScalculated from the increase in weight.Method No. 2.In this method and in the following ones,mud solids are obtained from the relationMud solids % 0= dry substance %- fibre%- Brix %(a)Dry substanceCalculated by drying a weighed amount offeed or cake to constant weight at 105°C.(b)(c)FibreDetermined as in Method No. 1 above.BrixBrix of feed is calculated from the expressionBrix =Pty.Pol o,~ feedclarified juicewhere Pol % feed is obtained by the sameanalytical procedure as that currently used forthe determination of pol in cake, and purityPol % g clarified juiceclarified juice C~---------- x 100Brix (dens.)Brix = --------- x 100Pty. 60/40 mixture-90 -x 100Brix of cake is caleulated from the expressionwhere the 60/40 mixture is one contammg 60per cent of cloudy filtrate and 40 per cent ofclear filtrate. The purity of the mixture is givenby the relationship.Method No. 3.Pol %s 60/40 mixture---------- x 100Brix (dens.)This method is similar to Method No. 2above. but instead of assuming a 60/40 mixture,a certain amount of cake is placed in a pieceof calico cloth and juice expressed. The purityof the expressed juice is calculated from therelationshipPol % g expressed juieeBrix(dens.)x 100and the Brix of the cake obtained by dividingpol ~.~ cake by purity of expressed juice andmultiplying by 100.Method No. 4.This method is similar to Method No. 2exeept that the Brix of feed and eake, instead ofbeing obtained by calculation, arc measureddirectly with the help of a refractometer. Forthis purpose a little feed is filtered throughcotton wool whilst a few millilitres of juice areexpressed from the cake with the help of apiece of calico cloth.Method No. 5.The only difference between this methodand No. 2 lies in the Brix calculation of thefeed and cake. Instead of determining thepurity of a 60/40 mixture, feed is strained in acalico cloth and the pol and densimetric Brixof the filtrate are measured.Then,Pol ~.~ g. filtratePurity of juice in feed =- x 100Brix (dens.)Pol % cake Pol % feedand Brix of feed-------- x 100Pty, juice in feed