Vacuum cleaning system

Abstract

A vacuum cleaning system comprising a vacuum cleaner having a vacuum motor, a dirt bin, a primary separation system, a membrane filter, and an air valve arrangement configured to control air flow through at least the membrane filter. The vacuum cleaner is configured to be operable in a surface cleaning mode and a self-cleaning mode. In the surface cleaning mode, the vacuum motor draws dirty air from a dirty-air inlet through the dirt bin, the primary separation system, and the membrane filter in a first airflow direction. In the self-cleaning mode, the vacuum cleaner permits air to flow from the air valve arrangement through the membrane filter in a second airflow direction to clean dirt from the membrane filter. The membrane filter may be positioned upstream from the vacuum motor or positioned downstream from the vacuum motor, when considered in an airflow direction during a surface cleaning mode.

Amendments to the claims: 
     
         1 . A vacuum cleaning system comprising a vacuum cleaner having a vacuum motor, a dirt bin, a primary separation system, a membrane filter, and an air valve arrangement configured to control air flow through at least the membrane filter;
 wherein the vacuum cleaner is configured to be operable in a surface cleaning mode of operation and a self-cleaning mode of operation;   wherein, in the surface cleaning mode of operation, the vacuum cleaner is configured such that the vacuum motor draws dirty air from a dirty-air inlet through the dirt bin, the primary separation system and the membrane filter in a first airflow direction, and   wherein, in the self-cleaning mode of operation, the vacuum cleaner is configured to permit air to flow from the air valve arrangement through the membrane filter in a second airflow direction to clean dirt from the membrane filter.   
     
     
         2 . The vacuum cleaning system of  claim 1 , wherein the air valve arrangement is further configured to cause air to flow across a surface of the membrane filter during the self-cleaning mode. 
     
     
         3 . The vacuum cleaning system of  claim 1 , wherein the membrane filter is selected from: an ePTFE membrane, PP membrane, PU membrane, Polyamide membrane, and a PVDF membrane. 
     
     
         4 . The vacuum cleaning system of  claim 3 , wherein the filter element has a filter efficiency of at least 50% at a particle size of 0.3 micrometres. 
     
     
         5 . The vacuum cleaning system of  claim 3 , wherein the filter element has an average fibril diameter of less than 100 nm. 
     
     
         6 . The vacuum cleaning system of  claim 1 , wherein the membrane filter is movably mounted within the vacuum cleaner, wherein movable mounting of the membrane filter is configured to assist in dislodging dirt from the membrane filter. 
     
     
         7 . The vacuum cleaning system of  claim 6 , wherein the membrane filter is movable from a first position to a second position when the vacuum cleaner enters the self-cleaning mode of operation to assist in dislodging dirt from the membrane filter. 
     
     
         8 . The vacuum cleaning system of  claim 7 , wherein in moving from the first position to the second position the membrane filter contacts an impactor configured to provide a mechanical impact pulse to the membrane filter. 
     
     
         9 . The vacuum cleaning system of  claim 6 , wherein movement of the membrane filter from the first position to the second position is caused by operation of the air valve arrangement. 
     
     
         10 . The vacuum cleaning system of  claim 6 , wherein movement of the membrane filter from the first position to the second position is caused by opening of the dirt bin door. 
     
     
         11 . The vacuum cleaning system of  claim 1 , wherein the membrane filter is at least a pre-motor filter, such that it is positioned upstream of the vacuum motor when considered in the direction of airflow in the surface cleaning mode of operation. 
     
     
         12 . The vacuum cleaning system of  claim 1 , wherein the membrane filter is at least a post-motor filter, such that it is positioned downstream of the vacuum motor when considered in the second airflow direction in the surface cleaning mode of operation. 
     
     
         13 . The vacuum cleaning system of  claim 1 , further comprising a docking station, wherein the docking station comprises a dirt storage chamber and an interface configured to mate with a dirt bin of the vacuum cleaner such that dirt expelled from the dirt bin through a bin opening is ejected into the dirt storage chamber of the docking station,
 wherein the vacuum cleaner is configured to evacuate air from the dirt storage chamber when docked with the docking station, wherein, in the self-cleaning mode, the vacuum cleaning system is configured to:   operate the vacuum motor to generate a partial vacuum in the dirt storage chamber, and   once a negative pressure level has been generated, operate the air valve arrangement to cause a pulse of air to flow from the air valve arrangement through the membrane filter in the second airflow direction.   
     
     
         14 . The vacuum cleaning system of  claim 13 , wherein one a negative pressure level has been generated, the air valve arrangement is operated to cause a pulse of air to flow into the dirt bin of the vacuum cleaner thereby to eject dirt from the dirt bin through the bin opening and into the dirt storage chamber. 
     
     
         15 . The vacuum cleaning system of  claim 13 , wherein the vacuum cleaner is configured such that the pulse of air admitted into the dirt bin during the self-cleaning mode flows firstly through the membrane filter. 
     
     
         16 . The vacuum cleaning system of  claim 15 , wherein the primary separation system includes at least one of a surface filter, a depth filter and a cyclonic separator. 
     
     
         17 . The system of  claim 1 , wherein the air valve arrangement has a total area that is configured to be not less than 0.5 times the cross sectional area of the dirt bin. 
     
     
         18 . The system of  claim 1 , wherein the air valve arrangement is configured to be operated by differential pressure between the dirt bin and ambient environment. 
     
     
         19 . The system of  claim 1 , wherein the air valve arrangement is configured to be operated repeatedly during sustained operation of the suction generator, thereby permitting a plurality of sequential air pulses to flow through the dirt bin.