Minimization of seasonal sucrose losses across Robert's-type evaporators in raw sugar manufacture by pH optimization.

Factory staff must consider all costs to make sound economic decisions on how to improve the performance of evaporators, which includes knowing optimum pH levels to minimize sucrose losses. A factory study was conducted to determine the effects of target final evaporator syrup (FES) pH values across the season on sucrose losses. The factory operated Robert's type calandria evaporators, with two (2787 and 2322 m2) preevaporators in parallel and three sets of triple-body evaporators (1148 m2 each) in parallel; Rt values were 11.4 and 9.5 min in the two preevaporators, respectively, and increased from 10.0 to 21.8 min across the triple bodies. Gas chromatography was used to determine sucrose losses as Δ%glucose/%sucrose ratios on a °Brix basis. Most sucrose losses to acid hydrolysis occurred in the preevaporators. Increasing the target pH of the FES or clarified juice (CJ) systematically reduced losses of sucrose; however, scaling effects overrode pH effects in later bodies. Seasonal effects on evaporator su...