# US 5,348,647 A · Water filter with back wash function

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- Number: US 5,348,647 A
- Document ID: US5348647A
- Status: Granted
- Kind: A
- Application number: 08/031,968
- Filed: 1993-03-16
- Granted: 1994-09-20
- Earliest claimed: 1993-03-16
- Inventors: T. H. Chen
- Web page: https://patentgrep.com/patent/US5348647A

## CPC

- B01D 29/33: arranged for inward flow filtration
- B01D 29/6415: {with a rotary movement with respect to the filtering element}
- B01D 29/904: {directing the mixture to be filtered on the filtering element in a manner to clean the filter continuously (B01D29/115, B01D29/118, B01D29/17, B01D29/25, B01D29/336, B01D29/356, B01D29/902, B01D29/908 take precedence)}
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)

## Abstract

A water filter is disclosed having a water reservoir in fluid communication with the porous ceramic core filter element and the drinking water control valve of a filter assembly, for holding a volume of water therein. The water reservoir provides a compressed air space, the air being compressed by an intake flow of water from the filter assembly. The compressed air in the water reservoir is released as a washing water control valve of the filter assembly is opened, thereby causing water from the reservoir to flow backwards through the filter element from inside out. This reverse flow carries dirt from small holes in the filter element, for draining from the washing water control valve.

## Claims

### Claim 1

An apparatus for cleaning water, comprising:
means for filtering water, said water filtering means including, (1) a first housing having at least one housing wall and a pair of opposing end members, one of said pair of end members having an orifice formed therethrough, (2) a porous ceramic core filter element disposed within said housing and having a longitudinally directed bore formed therein for passage of filtrate therethrough, said longitudinally directed bore of said porous ceramic core filter element being coupled in fluid communication with said orifice, (3) a water inlet formed in said housing wall for entry of raw water therethrough, (4) a conduit extending from said orifice external to said first housing, (5) a drinking water control valve coupled to a distal end of said conduit, said conduit providing fluid communication between said drinking water control valve and said longitudinally directed bore of said porous ceramic core filter element, and (6) a washing water control valve coupled to said housing wall and in fluid communication with an inlet chamber defined between said housing wall and an external surface of said porous ceramic core filter element, said filtrate being defined by water passing through said porous ceramic core filter element from said external surface thereof to said longitudinally directed bore; and
(7) means for back washing said porous ceramic core filter element with filtrate simultaneous with providing a flow of said raw water past said external surface thereof responsive to opening of said washing water control valve, said back washing means including means for storage of said filtrate and compressed air, said storage means including, (a) a second housing having a plurality of wall members for defining a closed cavity space therein, and (b) an inlet/outlet port formed on one end of said second housing, said back washing means further including means for conveying said filtrate from said storage means via said inlet/outlet port to said conduit disposed external to said first and second housings, wherein said compressed air within said storage means produces a flow of said filtrate through said porous ceramic core filter element from said longitudinally directed bore to said inlet chamber responsive to said washing water control valve being in an open condition for removing dirt particles from pores of said porous ceramic core filter element.