Hydraulic powered mixing apparatus

Claim 2

Mixing apparatus comprising: a tank for holding a volume of liquid; means for establishing an operating level for the liquid in the tank and a gas space above the liquid; an upright draft tube disposed within the tank extending from above the operating level of the liquid to below the operating level of the liquid, the draft tube being in fluid communication with the tank at a level below the operating level of the liquid; an impingement surface transverse to the draft tube below the level of fluid communication, the upper portion of the draft tube being in communication with gas above the liquid for admitting gas into the draft tube to be mixed with the liquid in the tank; a nozzle disposed within the draft tube at a substantial distance below the operating level for the liquid in the tank for directing a stream of liquid downwardly against the impingement surface; a flange on the draft tube and spaced between about 0.1" and about 1" above the impingement surface; and means for forcing the stream of liquid through the nozzle against the impingement surface to entrain bubbles of gas in the stream of liquid, the impingement surface and flange being disposed to deflect the stream of liquid and entrained bubbles radially outwardly from the draft tube into the volume of liquid in the tank.

Claim 3

Apparatus of claim 1 in which the impingement surface is spaced from the bottom of the tank by no more than about 1/4 of the operating level of the liquid in the tank.

Claim 4

The apparatus of claim 1 in which the impingement surface is a portion of the bottom of the tank.

Claim 5

The apparatus of claim 1 in which the nozzle is between about 1/8 inch and about 5 draft tube diameters above the impingement surface.

Claim 6

The apparatus of claim 1 further including means for adjusting the volumetric flow rate of liquid through the nozzle.

Claim 7

The apparatus of claim 1 further including means for adjusting the volumetric flow rate of gas through the gas tube.

Claim 8

Mixing apparatus comprising: a tank having a bottom and a side wall for holding a volume of liquid; means for establishing an operating level for the liquid in the tank; an upright draft tube disposed within the tank having an upper end in communication with a gas space above the operating level of liquid and a lower open end near the bottom of the tank; a liquid feed pipe extending downwardly within the draft tube for a substantial distance below where the upper end of the draft tube communicates with the gas space, the pipe being disposed within the draft tube to leave a path for the flow of gas between them, the pipe terminating in a nozzle disposed a substantial distance below the operating level for the liquid in the tank for directing a stream of liquid downwardly against the bottom of the tank; a flange on the draft tube and spaced between about 0.1" and about 1" from the bottom of the tank; and means for forcing a stream of liquid through the nozzle and out the space between the flange and the bottom of the tank to draw gas down the draft tube and create a pattern of bubbles flowing radially outwardly from the draft tube across the bottom of the tank and upwardly into the volume of liquid in the tank.

Claim 9

Mixing apparatus comprising: a tank having a bottom and a side wall for holding a volume of liquid; means for establishing an operating level for the liquid in the tank; an upright draft tube disposed within the tank having an upper end in communication with a gas space above the operating level of liquid and a lower open end near the bottom of the tank; a liquid feed pipe extending downwardly within the draft tube for a substantial distance below where the upper end of the draft tube communicates with the gas space, the pipe being disposed within the draft tube to leave a path for the flow of gas between them, the pipe terminating in a nozzle disposed a substantial distance below the operating level for the liquid in the tank for directing a stream of liquid downwardly against the bottom of the tank; a flange on the draft tube and spaced between about 0.1" and about 1" from the bottom of the tank; and means for forcing a stream of liquid through the nozzle and out the space between the flange and the bottom of the tank to draw gas down the draft tube and create a pattern of bubbles flowing radially outwardly from the draft tube across the bottom of the tank and upwardly into the volume of liquid in the tank.

Claim 10

The apparatus of claim 7 in which the nozzle is between about 1/8 inch and about 5 draft tube diameters from the bottom of the tank.

Claim 11

Apparatus of claim 7 further comprising means for adjusting the volumetric flow rate of liquid through the nozzle.

Claim 12

The apparatus of claim 7 comprising a plurality of said upright draft tubes, liquid feed pipes, and nozzles.

Claim 13

Flotation apparatus comprising: a first tank having a bottom and an upwardly extending wall; means for introducing into the first tank a two-phase liquid mixture having a liquid component and an immiscible component; a first mixing unit for adding and mixing gas with the two-phase liquid mixture to form gas bubbles which attach themselves to some of the immiscible component to buoy it to the surface in the form of a froth; a second tank adjacent to the first tank and having a bottom and an upwardly extending wall; an inlet in the second tank connected to an outlet in the first tank to receive a portion of the two-phase liquid mixture from the first tank; a second mixing unit for adding and mixing gas with the two-phase liquid mixture in the second tank to form gas bubbles which attach themselves to some of the insoluble component to buoy it to the surface in the form of a froth; means for establishing an operating level for liquid in each tank; each mixing unit for adding and mixing gas including an upright draft tube disposed within the tank having an upper end in communication with a gas space above the operating level of the liquid and a lower open end near the bottom of the tank, a liquid feed pipe extending downwardly within the draft tube for a substantial distance below where the upper end of the draft tube communicates with the gas space, the pipe being disposed within the draft tube to leave a path for the flow of gas between them, the pipe terminating in a nozzle disposed a substantial distance below the operating level for the liquid in the tank for directing a stream of liquid downwardly against the bottom of the tank; a flange on each draft tube and spaced between about 0.1" and about 1" above the bottom of the corresponding tank; and means for forcing the stream of liquid through each nozzle and out the space between the flange and the bottom of the corresponding tank to draw gas down the draft tube and create a pattern of bubbles flowing radially outwardly from each draft tube across the bottom of the corresponding tank and upwardly through the volume of liquid in the tank.

Claim 14

Flotation apparatus comprising: a first tank having a bottom and an upwardly extending wall; means for introducing into the first tank a two-phase liquid mixture having a liquid component and an immiscible component; a first mixing unit for adding and mixing gas with the two-phase liquid mixture to form gas bubbles which attach themselves to some of the immiscible component to buoy it to the surface in the form of a froth; a second tank adjacent to the first tank and having a bottom and an upwardly extending wall; an inlet in the second tank connected to an outlet in the first tank to receive a portion of the two-phase liquid mixture from the first tank; a second mixing unit for adding and mixing gas with the two-phase liquid mixture in the second tank to form gas bubbles which attach themselves to some of the insoluble component to buoy it to the surface in the form of a froth; means for establishing an operating level for liquid in each tank; each mixing unit for adding and mixing gas including an upright draft tube disposed within the tank having an upper end in communication with a gas space above the operating level of the liquid and a lower open end near the bottom of the tank, a liquid feed pipe extending downwardly within the draft tube for a substantial distance below where the upper end of the draft tube communicates with the gas space, the pipe being disposed within the draft tube to leave a path for the flow of gas between them, the pipe terminating in a nozzle disposed a substantial distance below the operating level for the liquid in the tank for directing a stream of liquid downwardly against the bottom of the tank; a flange on each draft tube and spaced between about 0.1" and about 1" above the bottom of the corresponding tank; and means for forcing the stream of liquid through each nozzle and out the space between the flange and the bottom of the corresponding tank to draw gas down the draft tube and create a pattern of bubbles flowing radially outwardly from each draft tube across the bottom of the corresponding tank and upwardly through the volume of liquid in the tank.

Claim 15

The apparaus of claim 11 in which the means for forcing the liquid through the nozzles includes a manifold connected to each liquid feed pipe, a pump connected to the manifold, and means for conveying a stream of treated liquid from an outlet of the second tank to the pump, whereby the pump forces treated liquid through the nozzles.

Claim 16

The apparatus of claim 11 further including gas tight cover means on the tanks for defining a sealed space in gas communication with the upper end of each draft tube, and means for admitting gas to the sealed space.