Abstract: Flotation apparatus (10) for removing finely divided bodies of an insoluble substance dispersed in an aqueous medium, such as oil and solids dispersed in water, comprises a vertical flotation column (12) having a feed inlet (14) and an outlet (22) for the aqueous medium, a sparging system (16) for generating gas bubbles rising upwardly in the aqueous medium to capture and raise the finely divided bodies of the insoluble substance to the surface of the aqueous medium in the column to form a layer (31) of the insoluble substance on the surface of the aqueous medium, a launder (18) for receiving an overflow of the insoluble substance and an outlet (20) for the insoluble substance in the launder. The apparatus (10) can be used in both countercurrent and co-current fashion. In a particular embodiment, the apparatus includes a mechanism for the intermittent dumping of the layer (31) of insoluble substance from the column (12).

Abstract: A sparger (100) for producing gas bubbles in a liquid comprises a body member (102) having a gas inlet (105) and an outlet portion (106) provided with a gas outlet (108). The outlet portion (106) has an internal bore (110) which is in communication with the gas inlet (105) and the gas outlet (108). The bore (110) has opposite sides which converge in the direction of the outlet (108) to form a tapered region (112) in the bore (110). The bore (110) has a substantially constant diameter along at least a part of its length in an area between the tapered region (112) and the outlet (108). The sparger (100) further comprises a valve member (114) which is moveable into said tapered region (112) towards the outlet (108) for controlling the flow of gas through the outlet (108).

Abstract: Flotation apparatus (10) for removing finely divided bodies of an insoluble substance dispersed in an aqueous medium, such as oil and solids dispersed in water, comprises a vertical flotation column (12) having a feed inlet (14) and an outlet (22) for the aqueous medium, a sparging system (16) for generating gas bubbles rising upwardly in the aqueous medium to capture and raise the finely divided bodies of the insoluble substance to the surface of the aqueous medium in the column to form a layer (31) of the insoluble substance on the surface of the aqueous medium, a launder (18) for receiving an overflow of the insoluble substance and an outlet (20) for the insoluble substance in the launder. The apparatus (10) can be used in both countercurrent and co-current fashion. In a particular embodiment, the apparatus includes a mechanism for the intermittent dumping of the layer (31) of insoluble substance from the column (12).

Abstract: Flotation apparatus (10) for removing finely divided bodies of an insoluble substance dispersed in an aqueous medium, such as oil and solids dispersed in water, comprises a vertical flotation column (12) having a feed inlet (14) and an outlet (22) for the aqueous medium, a sparging system (16) for generating gas bubbles rising upwardly in the aqueous medium to capture and raise the finely divided bodies of the insoluble substance to the surface of the aqueous medium in the column to form a layer (31) of the insoluble substance on the surface of the aqueous medium, a launder (18) for receiving an overflow of the insoluble substance and an outlet (20) for the insoluble substance in the launder. The apparatus (10) can be used in both countercurrent and co-current fashion. In a particular embodiment, the apparatus includes a mechanism for the intermittent dumping of the layer (31) of insoluble substance from the column (12).