AU664320B2 - Water filter with back wash function - Google Patents

Description

WATER FILTER WITH BACK WASH FUNCTION BACKGROUND OF THE INVENTION The present invention relates to water filters and relates more particularly to a water filter which provides a bac!: wash function to remove dirts from a filter elem'ent thereof through a back wash process.

A variety of water filters are known and widely used for removing dirts from water. Hn~ever, regular water filters reguires regular cleaning or replacement. Because the average individual lacks either the time or the knowledge necessary to carry out the task of cleaning the filter element, often the filter element is left uncleaned. U.S. Patent No.

5,080,788 discloses a water filter with fluid actuated cleaner which uses a rotator with roller brushes actuated by the intake flow of water to scrape off dirt adhered to the surface of the porous ceramic core thereof, therefore the frequency of cleaning or replacing the filter element can be reduced without affecting the performance of the water filter. Since the roller brushes can only remove dirts adhered to the surface of the filter element, dirts may be tangled in holes on the filter element to contaminate the flow of 1 p.

water passing through and create a restriction to the water flow volume.

SUMMARY OF THlE INVENTION The present invention eliminates the aforesaid problems. According to the present invention, a. water reservoir is disposed by the side, of a water filter device. The water reservoir has a bottom input/output port connected between a center hole through the longitudinal axiq of the filter element of the water filter device and the drinking water control valve thereof to hold a volume of water from the water filter device. As the washing water control valve of the water filter device was opened, a flow of water is forced to flow through the filter element inside out, 1s in carrying dirts from holes on the filter element for draining from the washing water control valve.

*4 4 BRIEF DESCRIPTION OF THE DRAWINGS (i rig. 1 is a sectional elevation of the preferred embodiment of the water filter of the present invention; Fig. 2 is an exploded perspective view of the water filter,- and 2I I~ Fig. 3 is a pergpective elevation of the water filter* flTAhRD DFlIRVRTPTTON -OF THTV PRFFERQF VSOT NT Referring to Figs. 1 and 2, a water filter as onstructed in acordanee with the present invention is generally comprised of a cylindrieal housing 1, a top cover 2, a filter eleaent 3, and a rotator A. The filter element 3 is vertically fastened inside the housing 1 at the center and supported on a washer 31.

The filter element 3 can be a porous eeramic core with J active carbon for removing solid matters from the flow of water passing through. The cylindrical housing 1 has San upper open end covered by the top cover 2 and sealed by a washer 21. The rotator A ia fastened inside the cylindrical housing 1 around the filter element 3, having upper and lower floats 4,4' and blades 41,41' assembled together with screws S and locknuts 51, Projecting posts 42,42' are disposed on a side of each i of the upper and lower blades 41,41 1 Access holes 61 on each end of the roller brushes 6 accommodate the Sprojecting portas for nmounting the roller brushes 6 thereon. An angled water spray inlet 13 is positioned adjacent the upper and lower blades 41,41', Isuch that flowing water drives the blades 41,41', after 3 I

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the openingj of either drinkingj water control valve 11 or wanhing water control valve 12# causing rotator to rotate. In this manner, the roller brushes 6 scrape of f dirt adhered to the surfaco of the filter element 3.

U1pon opening the washing wator control valve 12, the water containing the dislodged dirt will drain from the washing water control valve 12, without passing through the filter element 3. clean water quality is thereby mantained.

In order to main~tain the high performance of the filter element 3 and eliminates restrictions imposed to the water flow volume by dirts, an enclosed water reservoir 7 is disposed by the water filter and connected to the drinking water outlet pipe Ill by a bottom water pipe 72- As the driving And washing water control valves 11,12 are turned off, a continuous flow of water is filled into the water filter. Because the water reservoir 7 is communicated with the drinking water outlet pipe 111, continuoualy filling water into the water filter causes a flow of water to flow into the enclosed water reservoir 7 in compressing the inside air 71. As soon as the air pressure of the compressed air 71 and the water pressure of the intake flow of water 4

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are equalized, water is stopped from entering the water filter. Once the drinking water control valve 11 waF, opened, the compressedair 71 fore:: alow: of water to flow backwards through the bottom water pipe 72 into the filter element 3 continuously flows from the inside to the outside in carrying dirts from small holes on the filter element 3 while the roller brushes are rotated to scrape off dirt adhered to the surface of the filter element 3. As the performance of the filter element 3 is improved# a satisfactory filtration rate is constantly maintained, and therefore the water flow volume through the drinking water control valve 11 is never restricted.

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