Method for treating a liquid with a gas using an impeller
OwnerCharles E. Eckert, Nicholas G. Walkerinventors
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Abstract
An improved impeller head is provided for treating molten metals and other liquid systems with a gas. A multiple-vaned impeller head is adapted for mounting on a hollow impeller shaft for rotation within the liquid The edges of the impeller vanes are extended by an axial groove which intercepts the hub and the vanes of the impeller head. Extension of the trailing edge of the vanes creates greater turbulence in the liquid as the impeller is rotated in the liquid and increases the impeller's efficiency. The impeller vanes may also have canted leading surfaces which create an upward axial flow of liquid to discourage formation of a surface vortex. Multiple impellers may also be mounted on a shaft in the vessel and the gas may be introduced remotely.
Claims38
A method for treating a liquid with a gas comprising the steps of:
- a) containing the liquid in a vessel having an impeller mounted on a shaft for rotation about an upright axis, providing a predetermined number of radially projecting vanes on the impeller, and submerging the top and bottom faces of the impeller in the liquid;
- b) introducing a gas into the liquid below the surface of the liquid;
- c) intermixing the gas and the liquid by creating predominantly radial flow to maximize shear by rotating the impeller below the surface of the liquid;
- and
- d) suppressing downward flow along said upright axis to prevent the formation of a surface vortex in the liquid.
A method for treating a liquid with a gas comprising the steps of:
- a) containing the liquid in vessel having an impeller mounted on a shaft for rotation about an upright axis, said impeller having a predetermined number of radially extending vanes, said vanes each having a leading and trailing surface, and submerging the top and bottom faces of the impeller in the liquid;
- b) introducing a gas into the liquid below the surface of the liquid;
- c) intermixing the gas and the liquid by creating predominantly radial flow to maximize shear by rotating the impeller below the surface of the liquid;
- d) creating an upward flow of liquid along the upright axis by providing a canted leading surface on the vanes relative to the trailing surface which is operable to suppress downward flow upon rotating the impeller.
Dependencies are inferred from the claim text.