Water treatment in aqueous heat transfer apparatus

摘要

A capsule 1 (FIG. 1) for the treatment of water in an aqueous heat transfer apparatus comprises open top compartments 2, 3 and luges 6 to bear against and grip the inside of a passage in which the capsule is located. The open tops of the compartments are closed by means of covers of controlled release glass which dissolve in water at different rates. The capsule can be arranged to release a first dose of corrosion inhibitor on exposure to water under relatively milder conditions and a second dose of corrosion inhibitor on exposure to water under relatively severer conditions.