EJECTION METERING DEVICES FOR LIQUID REAGENTS

摘要

The problem of treating liquids with chemical reagents, for example, with corrosion and scale inhibitors is urgent in many branches of industry - chemical, petroleum, petrochemical, power engineering, and water supply. As a rule, required regents are employed in liquid form. The problem consists in ensuring a feed of liquid reagent to the liquid being treated so as to maintain a constant proportioned batch as the flow rate of the latter varies: K = q″/q′, (1) where q″ is the flow rate of reagent, and q′ is the flow rate of liquid being treated. Metering devices that automatically maintain a given proportioned batch are used to achieve this goal. The operation of ejection-type metering devices is based on the use of a pump with a regulated delivery of liquid reagent. An automatic control system, which includes a flow transducer for the liquid being treated, a microprocessor regulator, and an actuating mechanism, is employed to control the operation of this pump. Devices of this type ensure rather high batching accuracy; they are, however, structurally complex, and require an external power source, and highly qualified adjustment and maintenance. These devices are therefore used preferentially in the chemical departments of electric power plants and petroleum-refining establishments.