Pilot plant installation for the purification of raw juices – Part II: Optimization of the operating parameters in the preliming and main liming units

Results obtained from the operation of the pilot plant when modifying the operating parameters of the preliming and main liming units are presented. The operating parameters considered were the modification of the pH curve through the prelimer, the retention time in the preliming tank and the final pH value of the prelimed juice. Lime dosage and retention time were modified when main liming was considered.

Average data from the statistical treatment showed that the best purified juices were obtained when a linear pH curve through the prelimer was maintained. A retention time of 15 min and a final pH = 11.0 for prelimed juice were enough to ensure good quality of the second carbonatation juices.

The lime dosage necessary to obtain purified juices of adequate quality corresponded to a FCaO of 0.6–0.7 and the minimum retention time in the main liming tank had to be 20 min.