Ceramic foam filter
AssigneeSwiss Aluminium Ltd.
InventorsJohn C. Yarwood, James E. Dore, Robert K. Preuss
Life of this patent
Estimating the term…
Abstract
The disclosure teaches an improved ceramic foam filter particularly useful for filtering molten metal, and also a method for filtering molten metal. The filter is characterized by a combination of properties which makes it particularly suitable for use in filtering molten metal.
Claims14
A ceramic foam filter for use in filtering molten metal having an open cell structure characterized by a plurality of interconnected voids surrounded by a web of said ceramic, said filter having an air permeability in the range of from 400 to 8000 .times. 10.sup.-.sup.7 cm.sup. 2, a porosity of 0.80 to 0.95, a pore size of 5 to 45 pores per linear inch and a thickness of from 1/2 4 inches, said filter having substantial structural uniformity with a plurality of homogeneously distributed pore blockages throughout the foam.
A ceramic foam filter for use in filtering molten metal having an open cell structure characterized by a plurality of interconnected voids surrounded by a web of said ceramic, said filter having an air permeability in the range of from 400 to 2500 .times. 10.sup.-.sup.7 cm.sup.2, a porosity of 0.80 to 0.95, a pore size of 20 to 45 pores per linear inch and a thickness of from 1/2 to 4 inches, said filter having substantial structural uniformity with a plurality of homogeneously distributed pore blockages throughout the foam.
A ceramic foam filter having substantial structural uniformity for use in filtering molten aluminum having an open cell structure characterized by a plurality of interconnected voids surrounded by a web of said ceramic, said filter having an air permeability of from 1000 to 1500 .times. 10.sup.-.sup.7 cm.sup.2, a porosity of from 0.85 to 0.90, a pore size of from 25 to 35 pores per linear inch and a thickness of from 11/2 to 21/2 inches, said filter having a plurality of homogeneously distributed pore blockages throughout the foam.
A method of filtering molten metal through a disposable filter which comprises:
- A providing a mass of molten metal;
- B providing a ceramic foam filter having an open cell structure characterized by a plurality of interconnected voids surrounded by a web of said ceramic, said filter having an air permeability in the range of from 400 to 8000 .times. 10.sup.-.sup.7 cm.sup.2, a porosity of 0.80 to 0.95, a pore size of 5 to 45 pores per linear inch and a thickness of from 1/2 to 4 inches and having substantial structural uniformity with a plurality of homogeneous pore blockages throughout the foam;
- and
- C pouring said molten metal through said material at a rate of from 5 to 50 cubic inches per square inch of filter area per minute,
- thereby removing entrained solids from the molten metal.
Dependencies are inferred from the claim text.