# US 5,702,612 A · Method and apparatus for flotation separation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,612 A - Document ID: US5702612A - Status: Granted - Kind: A - Application number: 08/504,819 - Filed: 1995-07-20 - Granted: 1997-12-30 - Earliest claimed: 1995-07-20 - Assignees: University of Kentucky Research Foundation - Inventors: Xiang-Huai Wang - Web page: https://patentgrep.com/patent/US5702612A ## CPC - C02F 1/24: by flotation (C02F1/465 takes precedence) - B03D 1/028: {Control and monitoring of flotation processes; computer models therefor} - B03D 1/1406: {with special arrangement of a plurality of flotation cells, e.g. positioning a flotation cell inside another} - B03D 1/1431: {Dissolved air flotation machines} - B03D 1/1475: {Flotation tanks having means for discharging the pulp, e.g. as a bleed stream} - B03D 1/24: Pneumatic {(mixing gases or vapours with liquids B01F23/20)} - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B03D: FLOTATION; DIFFERENTIAL SEDIMENTATION (sedimentation in general B01D21/00; in combination with other separation of solids B03B; sink-float separation B03B5/28; detergents, soaps C11D) ## Abstract A flotation method and apparatus for separating a selected constituent from an effluent of an industrial process is provided. The apparatus includes a conditioning tank and a flotation cell. The conditioning tank allows mixing a flotation reagent with an effluent and includes a mechanism for also dissolving gas in the effluent within the conditioning tank. The flotation cell includes a dissolved gas flotation chamber having an overflow for recovering the selected constituent and a tailings drain. In addition, the flotation cell also includes an added gas flotation chamber having a sparger for injecting gas into the effluent, an overflow for recovering the selected constituent and a tailings drain. ## Claims ### Claim 1 A method of separating a selected constituent from an effluent of an industrial process comprising the steps of: mixing the effluent with a flotation reagent; dissolving gas into the effluent; introducing a resulting effluent, flotation reagent and dissolved gas mixture into a third chamber of a flotation cell acting as a rougher separator in fluid communication with a first chamber of the flotation cell under conditions promoting a release of dissolved gas as microbubbles in the mixture, said third chamber having a longitudinal axis extending at an angle substantially perpendicular to a longitudinal axis of said first chamber; recovering floated selected constituent from the first chamber and delivering non-floated tailings from the first chamber to a second chamber of the flotation cell; sparging gas into the non-floated tailings delivered to the second chamber; and recovering the selected constituent from the non-floated tailings being processed in the second chamber. ### Claim 2 (depends on 1) The method set forth in claim 1, wherein said introducing of the mixture into the first chamber is completed at a rate of between substantially 2-20 lpm. ### Claim 3 (depends on 2) The method set forth in claim 2, wherein said introducing the mixture into the third chamber is completed at a rate of between substantially 2-10 lpm. ### Claim 4 (depends on 3) The method set forth in claim 3, wherein said sparging of gas into the second chamber is completed at a rate of between substantially 0.2-3.5 liters of gas per minute. ### Claim 5 A flotation apparatus for separating a selected constituent from an effluent of an industrial process, comprising: a conditioning tank for mixing flotation reagent with the effluent; means for dissolving gas in the effluent; (1) a dissolved gas flotation chamber for completing dissolved gas flotation under otherwise quiescent conditions, said dissolved gas flotation chamber including an overflow for recovering the selected constituent and a tailings drain; (2) a sparged gas flotation chamber for completing sparged gas flotation, said sparged gas flotation chamber including a means for sparging gas into the tailings from the dissolved gas flotation chamber, an overflow for recovering the selected constituent and a tailings drain; and (3) conduit means for feeding a mixture of effluent and flotation reagent from said conditioning tank to said dissolved gas flotation chamber and tailings from said dissolved gas flotation chamber to said sparged gas flotation chamber. ### Claim 6 (depends on 5) The apparatus set forth in claim 5, wherein said gas dissolving means is a pressurized gas source for delivering gas under pressure to said conditioning tank. ### Claim 7 (depends on 5) The apparatus set forth in claim 5, further including a rougher separator chamber in fluid communication with said dissolved gas flotation chamber, said rougher separator chamber having a longitudinal axis extending substantially perpendicular to a longitudinal axis of said dissolved gas flotation chamber. ### Claim 8 (depends on 7) The apparatus set forth in claim 7, wherein said dissolved gas flotation chamber and said sparged gas flotation chamber are concentrically disposed relative to each other. ### Claim 9 (depends on 7) The apparatus set forth in claim 7, wherein said dissolved gas flotation chamber, said injected gas flotation chamber and said rougher separator chamber have a relative volume ratio of between 1:10:1 to 1:10:4. ### Claim 10 (depends on 5) The apparatus set forth in claim 5, wherein said sparging means is a sparger for producing bubbles having a size of substantially 400-900 .mu.m .