Stable water quality thanks to controlled ClO₂ disinfection in a large brewery

The Challenge

A large brewery in South Africa was struggling with highly fluctuating water quality and varying disinfectant concentrations from the local water supplier. These fluctuations jeopardized both microbiological safety and process stability, and thus the consistent quality of the beer. Disinfectant concentrations that are too low risk contamination, while concentrations that are too high can cause corrosion and interfere with the fermentation process. At the same time, monitoring and control had to be carried out continuously during ongoing brewing operations. A solution was sought for stable, controlled water disinfection for the entire brewery water supply.

The sera solution

sera implemented a central chlorine dioxide generation and dosing system based on the standardized sera CDG 250. In the system, sodium chlorite and hydrochloric acid are dosed using diaphragm pumps, converted to ClO₂ in the reactor, and then diluted to a stable solution of 2 g/l. Multiple dosing points in the brewery are supplied from a single storage tank, which reduces installation and investment costs. The measurement and control technology was implemented using the sera AQUASENSO transmitter and matching sensors. The retrofit of the existing systems was carried out during ongoing operations between two brewing processes, including integration into the Profibus control system.

Customer Benefits

• Stable, controlled disinfection of the entire brewery water supply despite fluctuating raw water quality
• Protection against under- and overdosing of disinfectant and the resulting process risks
• Central generation and flexible distribution of ClO₂ to multiple dosing points
• Successful retrofit without production downtime between two brewing processes

Summary

The project demonstrates that consistent product quality in breweries is only possible with controlled, monitored water disinfection—and that centralized ClO₂ generation with precise measurement technology provides a robust solution for this.