Patent ID: 9744485
Date: 2017-08-29
CPC Classifications: B01D,C02F

Claim:
1. A method of filtering a liquid, comprising: providing a metal filter media contained in a filter housing, wherein the metal filter media is a wedge wire filter media; directing an inlet flow through a tangential inlet nozzle and thereby centrifugally spinning the liquid around the metal filter media in the filter housing to separate some heavier solids that gravitationally flow to a contaminant collection area above a debris outlet and at least partially beneath the filter media; filtering the liquid through the metal filter media in one direction during a filtration mode to separate filtered liquid and solids, at least some of the solids forming a solids cake on the filter media, wherein the liquid is production water from a gas or oil fracking production location, the liquid having entrained therein at least 3 components from the group consisting of frac gel, frac sand, formation solids, and hydrocarbon liquids; directing the filtered liquid through an outlet port of the filter housing; directing solids toward the debris outlet for eventual collection in a collection tank; and periodically releasing the solids cake on the metal filter media with a gas pulse wherein gas drives at least some of the filtered liquid in a reverse direction through the metal filter media, wherein the periodically releasing further comprises multiple stages, including an initial stage wherein said gas drives at least some of the filtered liquid in a reverse direction through the filter media, a transition stage wherein said gas drives a mixture of filtered liquid and said gas in a reverse direction through the filter media, and a final stage wherein the gas finishes cleaning the filter element after the filtered liquid is evacuated from the filter media, wherein the gas pushes the solids and any liquid toward the debris outlet.