Self cleaning filter arrangement

Abstract

A self-cleaning system for a filter includes a filter element; a filter housing with first, second, and third ports; the first port being a fluid inlet; the second port being a fluid outlet, and the third port being a recirculation outlet, the first and second ports being on the upstream side of the filter element; the third port being on the downstream side of the filter element; enabling primary and transverse flow through the filter; whereby reverse flow via the third port is used to clean the filter element; the system including a one-way valve connected to the second port to inhibit reflux of drain fluid into filter. A recirculation pump and a drain pump are controlled to periodically drain the lint removed from the filter to the system drain.

1 . a filter arrangement for a domestic appliance comprising:
 a filter element and a filter housing; wherein the filter housing has a first port, a second port, and a third port; and
 wherein the first port and the second port are located on a first side of the filer element, and the third port is located on the second side of the filter element. 
   
     
     
         2 . The filter arrangement as claimed in  claim 1 , wherein the filter element divides the interior of the housing providing an unfiltered liquid path between the first port and the second port, and a filtered liquid path between the first port and the third port. 
     
     
         3 . The filter arrangement as claimed in  claim 2 , wherein the filter element includes a tubular filter. 
     
     
         4 . The filter arrangement as claimed in  claim 3 , wherein the filter element includes a first peripheral seal at a first end of the tubular filter and a second peripheral seal at a second end of the tubular filter;
 the first seal being located proximate the first port, and the second seal being located proximate the second port.   
     
     
         5 . The filter arrangement as claimed in  claim 1  further comprising a one-way valve on the downstream side of the second port, the valve being adapted to inhibit liquid to flow into the housing via the second port. 
     
     
         6 . The filter arrangement as claimed in  claim 5 , wherein the one-way valve includes a valve housing having a stepped through-bore defining a first bore and a second bore, the first bore being larger than the second bore and being on the downstream side thereof to provide a valve seat, the valve element being affixed to the valve seat at a distance from the rim of the smaller bore. 
     
     
         7 . The filter arrangement as claimed in  claim 6 , wherein it includes a second valve housing member having a third through bore larger than the first bore and adapted to fit within the second bore, the valve element being affixed by the interface between first valve housing member and the second valve housing member. 
     
     
         8 . The filter arrangement of  claim 1  used as part of a self-cleaning filter system, wherein the filter including a recirculation pump connected to the third port and a recirculation pipe having an outlet above the water level of a wash bowl. 
     
     
         9 . The self-cleaning filter system with filter arrangement as claimed in  claim 8 , wherein the filter including drain pump connected to the second port and adapted to draw water from the filter housing. 
     
     
         10 . The self-cleaning filter system with filter arrangement as claimed in  claim 9 , further comprising a one-way valve located downstream of the drain pump. 
     
     
         11 . The self-cleaning filter system with filter arrangement as claimed in  claim 10 , further comprising a programmable control means for controlling the operation of the recirculation pump and the drain pump. 
     
     
         12 . (canceled) 
     
     
         13 . The washing machine as claimed in  claim 22 , further comprising a programmable control means programmed to turn the recirculation pump off for a first period of time during the wash cycle, whereby water in the recirculation pipe is enabled to flow in a reverse direction through the third port of the filter housing to dislodge at least some of the matter entrapped in the filter. 
     
     
         14 . A method of operating a self-cleaning filter system in a washing machine having a wash bowl, a filter having an intake port, a drain port and a recirculation port, a recirculation path including a recirculation pump connected to the recirculation port and a recirculation pipe delivering recirculated water to the top of the tub, wherein the method comprising the steps of:
 operating the recirculation pump for a first time period, and turning the recirculation pump off to permit at least part of the liquid in the recirculation path to flow into the filter element to dislodge matter caught by the filter.   
     
     
         15 . The method of  claim 14 , further comprising the steps of:
 permitting at least part of the liquid in the recirculation path to flow transversely into the filter element to dislodge matter caught by the filter.   
     
     
         16 . A method as claimed in  claim 14 , further comprising the step of turning the recirculation pump on after a first time period after the recirculation pump was turned off. 
     
     
         17 . A method as claimed in  claim 16 , further comprising the step of repeated turning the recirculation pump on and off for a time interval two or more times. 
     
     
         18 . A method as claimed in  claim 17 , further comprising the step of turning the drain pump on to draw water out via the second port and beyond the one way valve after the recirculation pump has been turned on and off one or more times. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . A washing machine comprising:
 a wash bowl, the wash bowl having a base;   a self-cleaning filter system having a filter arrangement including a filter element and a filter housing, wherein the filter housing has a first port, a second port and a third port, and wherein the first port and the second port are located on a first side of the filter element and the third port is located on the second side of the filter element;   a recirculation path including a drain connection from the base of the wash bowl to the first port;   a recirculation pump, wherein the recirculation pump is connected to the third port;   a recirculation pipe connected to the outlet of the recirculation pump and extending above the maximum water level of the wash bowl;   a drain pump connected to the second port and adapted to draw water from the filter housing;   a one-way valve located downstream of the drain pump; and   programmable control means for controlling the operation of the recirculation pump and the drain pump.