Dishwasher,

Abstract

Dishwasher, comprising a first wash circulation system ( 7 ) with a wash circulation pump ( 6 ) to circulate washing liquid from a sump ( 5 ) to at least one spray device ( 3, 4 ) arranged in a wash tank ( 2 ), wherein a second circulation system ( 10 ) comprising a further pump and a filtration device ( 11 ) is provided to filter washing liquid independently from actuation of the circulation pump ( 6 ) of the first circulation system ( 7 ).

1 . Dishwasher, comprising a first wash circulation system with a wash circulation pump to circulate washing liquid from a sump to at least one spray device arranged in a wash tank, characterised in that a second circulation system comprising a further pump and a filtration device is provided to filter washing liquid independently from actuation of the circulation pump of the first circulation system. 
     
     
         2 . Dishwasher according to  claim 1 , wherein the filtration device comprises at least one of a micro fine filter and a fine filter. 
     
     
         3 . Dishwasher according to  claim 2 , wherein at least one filter of the filtration device forms part of the wall of the wash tank. 
     
     
         4 . Dishwasher according to  claim 3 , wherein a device for backwashing the filter is provided in the wash tank. 
     
     
         5 . Dishwasher according to  claim 4 , wherein the device for backwashing the filter comprises nozzles located at the outwardly facing ends of at least one spray arm. 
     
     
         6 . Dishwasher according to  claim 1 , wherein the first circulation system also comprises a filtration device. 
     
     
         7 . Dishwasher according to  claim 1 , wherein one of an additional filtration device and part of the filtration device is located in the sump. 
     
     
         8 . Dishwasher according to  claim 1 , wherein the further pump is the drain pump. 
     
     
         9 . Dishwasher according to  claim 8 , wherein a backflow valve is provided upstream of the drain pump. 
     
     
         10 . Dishwasher according to  claim 8 , wherein the second circulation system comprises a sedimentation chamber located downstream of the drain pump and having a micro fine filter in its upper part. 
     
     
         11 . Dishwasher according to  claim 10 , wherein the dishwasher comprises a junction having at least one inlet connected to the outlet side of the drain pump and at least two outlets, wherein a first outlet is connected to the sedimentation chamber and a second outlet is connected to a drain tube for final drainage of washing liquid. 
     
     
         12 . Dishwasher according to  claim 11 , wherein a u-like bend of the drain tube for finally draining washing liquid is located higher than the sedimentation chamber of the second circulation system. 
     
     
         13 . Dishwasher according to  claim 11 , wherein a switch is provided at the junction, wherein the switch is adapted selectively connect at least the inlet and the first outlet and the inlet and the second outlet. 
     
     
         14 . Dishwasher according to  claim 13 , wherein an outlet in the upper part of the sedimentation chamber is connected to the drain tube such that an overflow for a completely filled sedimentation chamber is formed. 
     
     
         15 . Dishwasher according to  claim 14 , wherein the drain pump is controllable to effect a tangential cleaning of the filter. 
     
     
         16 . Dishwasher according to  claim 14 , wherein a backflow valve is provided downstream of the outlet of the sedimentation chamber. 
     
     
         17 . Dishwasher according to  claim 13 , wherein the junction comprises a second inlet connected to an outlet in the upper part of the sedimentation chamber such that an overflow for a completely filled sedimentation chamber is formed and the switch can be actuated so that the first inlet is connected to the first outlet and at the same time the second inlet is connected to the first outlet, and so that the first inlet is connected to the second outlet. 
     
     
         18 . Dishwasher according to  claim 17 , wherein the switch can additionally be actuated so that the first inlet is connected to the first outlet and at the same time the second inlet and the second outlet are closed. 
     
     
         19 . Dishwasher according to  claim 1 , wherein the further pump is an additional pump. 
     
     
         20 . Dishwasher according to  claim 19 , wherein the additional pump draws washing liquid to be filtered from the sump. 
     
     
         21 . Dishwasher according to  claim 19 , wherein the additional pump draws washing liquid from an area of the sump separated by a fine filter from which area also the circulation pump draws washing liquid. 
     
     
         22 . Dishwasher according to  claim 20 , wherein the outlet of the additional pump is connected to an inlet located in the upper part of a sedimentation chamber, wherein a part of the sedimentation chamber's wall is formed as a micro fine filter, and the lower part of the sedimentation chamber has an outlet connected to a feeding tube leading from the sump to a drain pump, the backflow of washing liquid from the sedimentation chamber to the sump being prevented by a backflow valve. 
     
     
         23 . Dishwasher according to  claim 22 , wherein a u-like bend of the drain tube for finally draining washing liquid is located higher than the sedimentation chamber of the second circulation system. 
     
     
         24 . Dishwasher according to  claim 22 , wherein a sensor device adapted to sense a clogging of the filter is provided. 
     
     
         25 . Dishwasher according to  claim 24 , wherein the sensor device is a hydrostatic sensor. 
     
     
         26 . Dishwasher according to  claim 25 , wherein the second circulation system comprises a sedimentation chamber, wherein the sensor is connected to the upper end of the sedimentation chamber.