Method of and apparatus for filtering

Claim 2

In a deep bed filter, a pressure tank, a plurality of vertically disposed and spaced perforate tubes depending into said tank and arranged in concentric inlet and outlet groups, means joining the inlet group of said tubes to a source of dirty liquid, means joining the upper Ends of the outlet group of said tubes to an outlet for clean liquid, means joining the lower ends of said outlet tubes to a drain conduit, and a body of granular, finely divided alumina disposed in said tank and interposed between said tubes, the withdrawal of clean liquid from the upper ends of the outlet tubes preventing the flow of alumina particles from the tubes with the clean liquid, and the means joining the lower ends of said outlet tubes accommodating the drainage of liquid and any alumina from said outlet tubes.

Claim 3

In a method of filtering dirt from liquid at elevated temperatures and/or pressures, the steps of flowing the liquid through a filter bed consisting essentially of finely divided granular alumina to a plurality of outlet tubes embedded in said bed and precoated with alumina, accreting the dirt in the alumina, interrupting the flow of liquid, gravitationally transferring the filter bed and the precoated alumina to a separation location, thoroughly admixing liquid with the alumina and accreted dirt, decanting at least some of the liquid and the dirt admixed therewith, flowing a stream of liquid from a source of such liquid to the bed location, educting the alumina from the separation location into said stream, thereby transferring the alumina back to the bed location, and circulating liquid from said tank through said bed and out through said outlet tubes to precoat a portion of said bed onto said outlet tubes.

Claim 4

In a method of filtering ultra-fine particles from steam condensate in a turbine power plant, the condensate being a liquid at an elevated temperature in excess of 150* F., the steps of passing the condensate through a filtration medium in the form of a bed consisting essentially of grandular, at least 99 percent pure alumina, the bed being at least partially precoated on a tubular support, the bed having a thickness measured in the direction of liquid flow, of at least 1 inch, and the average particle size of said alumina ranging from about 44 to about 149 microns.

Claim 5

In a method of filtering in a filter having spaced inlet and outlet openings for the flow therethrough of an aqueous suspension at a temperature in excess of 150* F., the step of passing the suspension from said inlet opening to said outlet opening through a filter media interposed between said openings and consisting essentially of granular, finely divided aluminum oxide of a purity on the order of 99 percent and having an average particle size ranging from about 44 microns to about 149 microns.