Filtration of fluid media

Claim 3

A method as recited in claim 1 comprising the further step of periodically cleaning the filter by effecting a reverse pulse of compressed air therethrough.

Claim 4

A method as recited in claim 1 wherein the fluid media is an acidic or alkaline gas having a temperature of about 1600° C. or more; and comprising the further step of reusing the hot gas in a constructive process after filtration.

Claim 5

An elongated tubular filter comprising: a plurality of porous ceramic material tubular portions, each tubular portion comprising ceramic fiber and a binder; said plurality of tubular portions comprising a first plurality having a first cross-sectional area, and further comprising a second plurality having a second cross-sectional area greater than said first cross-sectional area, so that said second portions are adapted to receive said first portions therein; and means for holding said first and second pluralities of said tubular portions in axially aligned end-to-end relation, respectively, to form a composite elongated tubular filter, comprising means defining an overlapping configuration of the portions including said second portions receiving said first portions, and an adhesive at bonding points associated with said overlapping configuration including between the ends of said axially aligned first and second pluralities of said tubular portions, respectively, and wherein the bonding points between the portions of said first plurality are off-set axially with respect to the bonding points between said second plurality.

Claim 6

An elongated tubular filter comprising: a plurality of porous ceramic material tubular portions, each tubular portion comprising ceramic fiber and a binder; said plurality of tubular portions comprising a first plurality having a first cross-sectional area, and further comprising a second plurality having a second cross-sectional area greater than said first cross-sectional area, so that said second portions are adapted to receive said first portions therein; and means for holding said first and second pluralities of said tubular portions in axially aligned end-to-end relation, respectively, to form a composite elongated tubular filter, comprising means defining an overlapping configuration of the portions including said second portions receiving said first portions, and an adhesive at bonding points associated with said overlapping configuration including between the ends of said axially aligned first and second pluralities of said tubular portions, respectively, and wherein the bonding points between the portions of said first plurality are off-set axially with respect to the bonding points between said second plurality.

Claim 7

A filter as recited in claim 4 wherein said ceramic fiber is selected from the group consisting of alumina fibers, alumino-silicate fibers, and mixtures of alumina and alumino-silicate fibers, said fibers present in an amount from 35-95% by weight.

Claim 8

A filter as recited in claim 5 wherein said binder is a colloidal oxide hydrosol.

Claim 9

A filter as recited in claim 4 wherein said tubular portions are vacuum formed from an aqueous slurry of ceramic fiber and binder.

Claim 10

A filter as recited in claim 7 wherein said aqueous slurry further includes a flocculating agent.

Claim 11

A filter as recited in claim 8 wherein said flocculating agent is a cationic starch.

Claim 12

A filter as recited in claim 4 wherein said porous ceramic tubular portions have a porosity of between 50-95%.

Claim 13

A filter as recited in claim 10 wherein the resistance to flow of air through the filter is in the range of from about 1×10 5 to about 1×10 8 Nm -4 s.

Claim 14

A filter as recited in claim 4 wherein the resistance to flow of air through the filter is in the range of from about 1×10 5 to about 1×10 8 Nm -4 s.

Claim 15

A filter as recited in claim 4 wherein said binder is a colloidal oxide hydrosol.

Claim 16

A filter as recited in claim 4 wherein said holding means consists of said overlapping second and first portions and said adhesive.

Claim 17

A filter as recited in claim 4 wherein said filter is comprised of substantially continuously extending outer and inner tubular portions defining a dual thickness filter at substantially each axial position therealong.