System for separating hydrocarbons from water

Claim 1

In a system for removing hydrocarbon pollutant from a water stream to provide a purified effluent stream, that improvement comprising a separator for removing from said stream free and entrained hydrocarbon, said separator having separate hydrocarbon and water outlets, a mechanical emulsion breaker for removing emulsified hydrocarbon from said stream, said emulsion breaker having an inlet connected to said separator water outlet, a control mounted to continuously sense the hydrocarbon-water interface in said separator, and valves for controlling the flow rates through said outlets, said control being connected to said valves for adjustment of said flow rates in response to changes in the position and said interface to counteract changes therein, said system being closed and pressurized and a fluid analyzer and associated conduit means for continuously sampling the water effluent from said emulsion breaker and returning the sample to said effluent stream, said analyzer including means for initiating the recycling of said effluent when hydrocarbon concentration therein reaches a threshold, while continuing to sample said effluent.