FLUID INJECTION APPARATUS AND METHOD

摘要

An additive fluid is selectively injected into a process fluid in a pipeline or well using an injection line (11a, lib, lie, Hd, He) in which there is a directional control valve (25). The valve is operated in a pulsed mode such that it is pulsed between open and closed positions, the pulse rate in effect controlling the flow rate of the additive fluid in the injection line. The pulse rate is selected in response to a parameter of the fluid additive such as, for example, the pressure difference between the fluid in a supply line (13) and in the injection line.