Regenerating of casting sand

Claim 2

In a method of regenerating casting sand, the steps of subjecting contaminant-coated spent casting sand to mechanical agitation; accelerating fresh uncontaminated casting sand; and contacting the accelerated fresh casting sand with said spent casting sand so that said fresh and said spent casting sand are admixed and the contaminant coating on said spent casting sand is at least partially scoured off by said fresh casting sand.

Claim 3

A method as defined in claim 1, wherein the contacting step is performed prior to the agitating step.

Claim 4

A method as defined in claim 1, wherein the contacting step is performed substantially simultaneously with the agitating step.

Claim 5

A method as defined in claim 1, wherein at least 10 percent of said fresh sand is admixed with said spent sand.

Claim 6

A method as defined in claim 1, wherein the accelerating step comprises entraining said fresh sand in a stream of gaseous fluid and the contacting step comprises entraining said spent sand in said stream of gaseous fluid; and wherein said mechanical agitation comprises impacting the entrained sand against an obstacle.

Claim 7

In an apparatus for regenerating casting sand, a combination comprising upright conduit means having an inlet at a lower region thereof for the introduction of pressurized gaseous fluid and an outlet at an upper region thereof; first admitting means at a level of said conduit means equal to at least the level of said inlet for the admission of fresh uncontaminated casting sand into said conduit means so as to permit entrainment of said fresh casting sand by said gaseous fluid; second admitting means intermediate said first admitting means and said outlet for the admission of spent contaminant-coated casting sand into said conduit means so as to permit entrainment of said spent casting sand by said gaseous fluid and an at least partial scouring off of the contaminant coating on said spent casting sand by said fresh casting sand; and impact baffle means adjacent said outlet for impaction of the entrained fresh and spent casting sand so as to permit mechanical agitation of said fresh and said spent casting sand.

Claim 8

In an apparatus for regenerating casting sand, a combination comprising upright conduit means having an inlet at a lower region thereof for the introduction of pressurized gaseous fluid and an outlet at an upper region thereof; first admitting means at a level of said conduit means equal to at least the level of said inlet for the admission of fresh uncontaminated casting sand into said conduit means so as to permit entrainment of said fresh casting sand by said gaseous fluid; second admitting means intermediate said first admitting means and said outlet for the admission of spent contaminant-coated casting sand into said conduit means so as to permit entrainment of said spent casting sand by said gaseous fluid and an at least partial scouring off of the contaminant coating on said spent casting sand by said fresh casting sand; and impact baffle means adjacent said outlet for impaction of the entrained fresh and spent casting sand so as to permit mechanical agitation of said fresh and said spent casting sand.

Claim 9

A combination as defined in claim 6, wherein said first and second admitting means each comprise a funnel surrounding said conduit means and communicating with the interior of the latter via a respective aperture.

Claim 10

A combination as defined in claim 6, wherein said first and second means are so arranged relative to one another that said fresh sand has a higher speed than the admitted spent sand at the time of contact with the latter.