Microbiological problems in the manufacture of sugar from beet. Part I. Corrosion in the diffusion battery and in the recirculation system

• Published in: Journal of the Society of Chemical Industry (Online) 1948-02, Vol.67 (2), p.70-77
• Main Authors: Allen, L. A., Cairns, A., Eden, G. E., Wheatland, A. B., Wormwell, F., Nurse, T. J.
• Format: Article
• Language: English
• ISSN: 0368-4075; 1934-9971
• DOI: 10.1002/jctb.5000670210

Corrosion in the return water circuit of a beet sugar factory is due to acids produced by the growth of lactobacilli of the L. delbrücki type which lower the pH value to the region of 4·0‐4·5. Laboratory tests showed that these organisms grew well at 50° and 60° but not at 70°, and that they were destroyed by a dose of 40 p.p.m. chlorine acting for 25‐30 minutes at 55°. In factory trials addition of lime to the recirculating liquor reduced total corrosion but gave rise to localized attack; this might be avoided by suitable control of pH value. Doses of chlorine of 200 lb. a day (18·7 p.p.m.) or more, applied continuously to the battery supply water, were found to raise the pH value of the return water to the region of 5·5‐6·25. Corrosion was reduced by about 90% in the sand tank and by a substantial though smaller amount in the battery pit. Chlorination made little difference to the corrosion occurring in the diffusion cells. During chlorination the amount of moisture retained by the pressed pulp was considerably increased.