Water Recycling System for Mobile Surface Cleaners

Abstract

A mobile surface cleaner has a mobile body configured to travel to areas to be cleaned. A dispensing system attached to the mobile body dispenses liquid on a surface as dispensed liquid. A recovery system attached to the mobile body recovers dispensed liquid as recovered liquid. A regenerative media filter attached to the mobile body filters the recovered liquid to form filtered liquid that can be dispensed by the dispensing system.

What is claimed is: 
     
         1 . A mobile surface cleaner comprising:
 a mobile body configured to travel to areas to be cleaned;   a dispensing system attached to the mobile body for dispensing liquid on a surface as dispensed liquid;   a recovery system attached to the mobile body for recovering dispensed liquid as recovered liquid; and   a regenerative media filter attached to the mobile body for filtering the recovered liquid to form filtered liquid that can be dispensed by the dispensing system.   
     
     
         2 . The mobile surface cleaner of  claim 1  further comprising at least one back flow path through the regenerative media filter whereby fluid is passed along the back flow path to cause a redistribution of regenerative media on the regenerative media filter. 
     
     
         3 . The mobile surface cleaner of  claim 2  wherein the recovery system comprises a vacuum source to draw liquid from a surface and to draw liquid along the back flow path to cause the redistribution of the regenerative media. 
     
     
         4 . The mobile surface cleaner of  claim 3  further comprising a pressure sensor positioned between the recovery system and the regenerative media filter. 
     
     
         5 . The mobile surface cleaner of  claim 4  further comprising a controller that controls whether the regenerative media filter filters recovered liquid to form filtered liquid or liquid passes through the back flow path to redistribute the regenerative media based at least in part on a sensor signal provided by the pressure sensor. 
     
     
         6 . The mobile device of  claim 5  further comprising at least one valve assembly such that:
 in a first configuration, the valve assembly connects the recovery system to the delivery system through the regenerative media filter to permit liquid from the recovery system to be filtered by the regenerative media filter to produce filtered liquid; and 
 in a second configuration, the valve assembly connects the delivery system to the recovery system through the regenerative media filter to permit liquid from the delivery system to back flow through the regenerative media filter. 
 
     
     
         7 . The mobile surface cleaner of  claim 1  further comprising a regenerative media reservoir located between the recovery system and the regenerative media filter. 
     
     
         8 . The mobile surface cleaner of  claim 7  wherein the regenerative media reservoir comprises a removable container. 
     
     
         9 . The mobile surface cleaner of  claim 8  wherein the regenerative media reservoir comprises a disposable container. 
     
     
         10 . The mobile surface cleaner of  claim 2  wherein the recovery system comprises a recovery tank and at least one level detector that detects when liquid in the recovery tank is above a threshold level and wherein the mobile surface cleaner indicates that the regenerative media should be replaced when liquid in the recovery tank is above the threshold level. 
     
     
         11 . An apparatus comprising:
 a movable body;   a tank movable with the movable body and receiving liquid recovered from an external surface; and   a regenerative media filter movable with the movable body and filtering liquid from the tank to form filtered liquid that can be dispensed on an external surface for cleaning.   
     
     
         12 . The apparatus of  claim 11  wherein in a first state, liquid from the tank is filtered by the regenerative media filter and in a second state, filtered liquid passes back through the regenerative media filter to redistribute regenerative media. 
     
     
         13 . The apparatus of  claim 12  further comprising a pressure sensor and a controller that controls whether the apparatus is in the first state or the second state based on a signal from the pressure sensor. 
     
     
         14 . The apparatus of  claim 12  wherein the tank continues to receive liquid recovered from the external surface while the apparatus is in the second state. 
     
     
         15 . The apparatus of  claim 12  further comprising a valve having three fluid path connections wherein a first fluid path connection is connected to a first path to the tank, a second fluid path connection is connected to a second path to the tank and a third fluid path connection is connected to a fluid path to the regenerative media filter and wherein the valve connects the first fluid path to the third fluid path when the apparatus is in the first state and connects the second fluid path to the third fluid path when the apparatus is in the second state. 
     
     
         16 . The apparatus of  claim 11  further comprising a vacuum source connected to the tank to draw liquid from the external surface into the tank and to draw filtered water through the regenerative media filter when the apparatus is in the second state. 
     
     
         17 . The apparatus of  claim 11  further comprising a regenerative media reservoir for providing regenerative media for the regenerative media filter. 
     
     
         18 . The apparatus of  claim 11  further comprising a level detector wherein the tank stops receiving liquid from the external surface when the level detector indicates that the liquid in the tank crosses a threshold. 
     
     
         19 . The apparatus of  claim 11  further comprising an electrolysis cell configured so that the filtered liquid is passed through the electrolysis cell before being dispensed on the external surface. 
     
     
         20 . A machine-implemented cleaning method comprising:
 dispensing liquid from a mobile cleaner on a surface to be cleaned;   drawing the dispensed liquid into the mobile cleaner to form recovered liquid;   passing the recovered liquid through a regenerative media filter in the mobile cleaner to form filtered liquid; and   dispensing the filtered liquid from the mobile cleaner on a surface to be cleaned.   
     
     
         21 . The method of  claim 20  further comprising:
 regenerating the regenerative media filter at least once without adding new regenerative media; 
 after regenerating the regenerative media filter, passing additional recovered liquid through the regenerative media filter in the mobile cleaner to form additional filtered liquid; and 
 dispensing the additional filtered liquid from the mobile cleaner on a surface to be cleaned. 
 
     
     
         22 . The method of  claim 21  further comprising:
 determining that the regenerative media needs to be replaced based on a level of liquid in a tank. 
 
     
     
         23 . The method of  claim 21  further comprising before regenerating the regenerative media filter, measuring a pressure in a conduit and using the measured pressure to determine that the regenerative media filter should be regenerated. 
     
     
         24 . The method of  claim 21  further comprising adding new regenerative material by adding a paste or dissolvable cake of regenerative material to the mobile cleaner. 
     
     
         25 . The method of  claim 21  wherein regenerating the regenerative media filter comprises using a vacuum source attached to a recovery tank to draw the filtered liquid through the regenerative media filter. 
     
     
         26 . The method of  claim 25  further comprising while using the vacuum source attached to the recovery tank to draw the liquid through the regenerative media filter, simultaneously using the same vacuum source to draw the dispensed liquid into the mobile cleaner to form the recovered liquid.