Closed Loop Chlorination and Placement

Chlorination control has come of age. Recent advancements in instrumentation have enabled the water treatment industry to accomplish economically what was in the past a hit-or-miss proposition. Residual analyzers are now playing a major role in the efficient operation of both existing and newly constructed water treatment plants. To better evaluate these developments, a number of factors should be considered. Of prime importance would be the initial benefits of residual control. Equally relevant is its economic justification. Various aspects of system design are explored with particular emphasis being placed on the areas of major concern, such as control loop lag time, chlorinator sizing, and proportional control. Problems inherent to water and sewage treatment are studied and recommendations for improvement are proposed. Specific cases are cited and described in some detail to illustrate these points.