Metering device for introducing chlorine or similar - gas into town water supplies or sewers

摘要

A feed pipe leads from the gas pipe to the water pipe and the gas pipe contains both a restrictor and a control valve which is power-driven under the control of a regulator to which a pressure drop is transmitted by pressure sensor/transmitters upstream and downstream of the restrictor. A signal generator measures fluctuations in the flow per unit time in the water pipe and transmits a corresponding signal to the regulator to control the gas flow in accordance with the water flow. The control valve drive is by gas through a branch from the gas pipe, or by means of a separate air supply.