Flotation machine

Claim 2

In a flotation machine comprising a flotation cell having an air inlet pipe for introducing air into the liquid being treated, a rotatable impeller for mixing the air with the liquid and circulating same in the cell, and an annular dispersing unit having a central opening in which said impeller is disposed and having a series of circumferentially spaced guide vanes defining flow passages for directing flow of the air and the liquid from the impeller, the improvement which comprises: each guide vane has an integral projecting portion on its leading side, in the direction of rotation of said impeller, said portion projecting toward the trailing side of the adjacent leading guide vane and defining therewith a zone which converges and then diverges in a direction away from the central opening of the dispersing unit, for causing subdivision of air bubbles in the liquid.

Claim 3

A flotation machine according to claim 1, in which said dispersing unit comprises a series of guide vanes which are forwardly curved in the direction of rotation of said impeller, said dispersing unit being stationarily mounted on the lower end of said air inlet pipe and adjacent to the bottom wall of the cell, said dispersing unit being coaxial with the axis of the rotation of said impeller.

Claim 4

In a flotation machine comprising a flotation cell having an air inlet pipe for introducing air into the liquid being treated, a rotatable impeller for mixing the air with the liquid and circulating same in the cell, and an annular dispersing unit having a central opening in which said impeller is dIsposed and having a series of circumferentially spaced guide vanes defining flow passages for directing flow of the air and the liquid from the impeller, the improvement which comprises: each guide vane has a concavo-convex shape with the concave side thereof being the leading side of the vane in the direction of rotation of said impeller, each guide vane having a member disposed in contact with the concave side thereof and extending partway across the flow passage defined between said vane and the convex side of the adjacent leading vane, and defining therewith a flow passage zone which converges and then diverges in a direction away from the central opening of the dispersing unit.

Claim 5

In a flotation machine comprising a flotation cell having an air inlet pipe for introducing air into the liquid being treated, a rotatable impeller for mixing the air with the liquid and circulating same in the cell, and an annular dispersing unit having a central opening in which said impeller is dIsposed and having a series of circumferentially spaced guide vanes defining flow passages for directing flow of the air and the liquid from the impeller, the improvement which comprises: each guide vane has a concavo-convex shape with the concave side thereof being the leading side of the vane in the direction of rotation of said impeller, each guide vane having a member disposed in contact with the concave side thereof and extending partway across the flow passage defined between said vane and the convex side of the adjacent leading vane, and defining therewith a flow passage zone which converges and then diverges in a direction away from the central opening of the dispersing unit.

Claim 6

A flotation machine according to claim 3, in which said dispersing unit comprises a series of guide vanes which are forwardly curved in the direction of rotation of said impeller, said dispersing unit being stationarily mounted on the lower end of said air inlet pipe and adjacent to the bottom wall of the cell, said dispersing unit being coaxial with the axis of rotation of said impeller.

Claim 7

In a flotation machine comprising a flotation cell having an air inlet pipe for introducing air into the liquid being treated, a rotatable impeller for mixing the air with the liquid and circulating same in the cell, and an annular dispersing unit having a central opening in which said impeller is disposed and having a series of circumferentially spaced guide vanes defining flow passages for directing flow of the air and the liquid from the impeller, the improvement which comprises: projecting portions integral or contiguous with the guide vanes and located thereon between the central opening and the periphery of said dispersing unit, each portion projecting toward the opposing surface of the adjacent guide vane and extending partway across the flow passage defined between said adjacent guide vanes and forming a narrowed zone in said flow passage for causing subdivision of air bubbles in the liquid, said flow passage being enlarged relative to said narrowed zone on opposite sides of said zone.

Claim 8

In a flotation machine comprising a flotation cell having an air inlet pipe for introducing air into the liquid being treated, a rotatable impeller for mixing the air with the liquid and circulating same in the cell, and an annular dispersing unit having a central opening in which said impeller is disposed and having a series of circumferentially spaced guide vanes defining flow passages for directing flow of the air and the liquid from the impeller, the improvement which comprises: projecting portions integral or contiguous with the guide vanes and located thereon between the central opening and the periphery of said dispersing unit, each portion projecting toward the opposing surface of the adjacent guide vane and extending partway across the flow passage defined between said adjacent guide vanes and forming a narrowed zone in said flow passage for causing subdivision of air bubbles in the liquid, said flow passage being enlarged relative to said narrowed zone on opposite sides of said zone.

Claim 9

IN A FLOTATION MACHINE COMPRISING A FLOTATION CELL HAVING AN AIR INLET PIPE FOR INTRODUCING AIR INTO THE LIQUID BEING TREATED, A ROTATABLE IMPELLER FOR MIXING THE AIR WITH THE LIQUID AND CIRCULATING SAME IN THE CELL, AND AN ANNULAR DISPERSING UNIT HAVING A CENTRAL OPENING IN WHICH SAID IMPELLER IS DISPOSED AND HAVING A SERIES OF CIRCUMFERENTIALLY SPACED GUIDE VANES DEFINING FLOW PASSAGES FOR DIRECTING FLOW OF THE AIR AND THE LIQUID FROM THE IMPELLER, THE IMPROVEMENT WHICH COMPRISES: A PROJECTING PORTION DISPOSED IN EACH OF SAID FLOW PASSAGES BETWEEN THE OPPOSING SURFACES OF THE ADJACENT GUIDE VANES THAT DEFINE THE FLOW PASSAGE, THE PROJECTING PORTION BEING LOCATED IN THE FLOW PASSAGE BETWEEN AND SPACED RADIALLY FROM SAID CENTRAL OPENING AND THE PERIPHERY OF SAID DISPERSING UNIT, THE PROJECTING PORTION EXTENDING FROM ONE SIDE OF THE FLOW PASSAGE TOWARD THE OTHER SIDE OF THE FLOW PASSAGE PARTWAY ACROSS THE FLOW PASSAGE AND NARROWING THE WIDTH OF SAID FLOW PASSAGE, WITH THE WIDTH OF SAID FLOW PASSAGE BEING ENLARGED ON OPPOSITE SIDES OF SAID PROJECTING PORTION.

Claim 10

IN A FLOTATION MACHINE COMPRISING A FLOTATION CELL HAVING AN AIR INLET PIPE FOR INTRODUCING AIR INTO THE LIQUID BEING TREATED, A ROTATABLE IMPELLER FOR MIXING THE AIR WITH THE LIQUID AND CIRCULATING SAME IN THE CELL, AND AN ANNULAR DISPERSING UNIT HAVING A CENTRAL OPENING IN WHICH SAID IMPELLER IS DISPOSED AND HAVING A SERIES OF CIRCUMFERENTIALLY SPACED GUIDE VANES DEFINING FLOW PASSAGES FOR DIRECTING FLOW OF THE AIR AND THE LIQUID FROM THE IMPELLER, THE IMPROVEMENT WHICH COMPRISES: A PROJECTING PORTION DISPOSED IN EACH OF SAID FLOW PASSAGES BETWEEN THE OPPOSING SURFACES OF THE ADJACENT GUIDE VANES THAT DEFINE THE FLOW PASSAGE, THE PROJECTING PORTION BEING LOCATED IN THE FLOW PASSAGE BETWEEN AND SPACED RADIALLY FROM SAID CENTRAL OPENING AND THE PERIPHERY OF SAID DISPERSING UNIT, THE PROJECTING PORTION EXTENDING FROM ONE SIDE OF THE FLOW PASSAGE TOWARD THE OTHER SIDE OF THE FLOW PASSAGE PARTWAY ACROSS THE FLOW PASSAGE AND NARROWING THE WIDTH OF SAID FLOW PASSAGE, WITH THE WIDTH OF SAID FLOW PASSAGE BEING ENLARGED ON OPPOSITE SIDES OF SAID PROJECTING PORTION.

Claim 11

A flotation machine as claimed in claim 6, in which said projecting portion is located closer to said central opening than to the periphery of said dispersing unit.

Claim 12

A flotation machine as claimed in claim 6, in which said projecting portion extends from the leading side of one vane, in the direction of rotation of the impeller, partway toward the trailing side of the adjacent guide vane.