Floating valve assembly for removing lighter phase - from immiscible heavier phase via flexible pipe double float arrangement such that valve closes at predetermined depth of lighter layer

摘要

A light liquid such as oil is creamed from the surface of a heavier liquid with which it is immiscible such as water by means of a pair of floats attached to a discharge hose. The floats are so desinged that one floats on the surface of the lighter fluid whilst the other floats at the interface between the heavier and the lighter fluid. a valve within the lower float is opened and closed by the movement of the upper float so that the valve only opens when the depth of th e lighter fluid exceeds a predetermind value. The lighter fluid discharges via a central hole in the lower float in which there is a valve seat. The valve stem is coaxial with this hole and is attached to the upper float, suitably restrained by support/guide bushes. Valve seat components are pref. of Teflon. (RTM). Weights can be added to a retaining arrangement on the lower float to accurately control its buoyancy. The floats are pref. restrained to move in a vertical axis by means of guide cables attached to the storage vessel. The float ensure that there is no carryover of heavier fluid with the lighter fluid that is drawn off.