Gravity filter designs configured for increased residence time

Abstract

Embodiments of water filters comprise a filter housing configured to be disposed in a pour tray of a water filter pitcher, wherein a filter media cartridge is disposed inside the filter housing. The filter housing includes a housing floor, housing sidewalls extending upwardly, away from the housing floor, and at least one filter housing outlet disposed in one or more of the housing floor or the housing sidewalls. The filter media cartridge includes filter media, where the filter media cartridge comprises a cartridge floor spaced above the housing floor, cartridge sidewalls extending upwardly, away from the cartridge floor, and at least one filter media cartridge outlet disposed along one or more of the cartridge floor or the cartridge sidewalls. The water filter pitcher further includes a riser extending upwardly, away from the housing floor, and spaced between the housing sidewalls and the cartridge sidewalls, where the riser extends a distance above the cartridge floor. The riser forms a conduit volume.

What is claimed is: 
     
         1 . A water filter configured to be inserted into a filter housing disposed in a pour tray of a water filter pitcher, wherein the filter housing comprises a housing floor; housing sidewalls extending upwardly from the housing floor; at least one filter housing outlet disposed in the housing floor, the housing sidewalls, or both; and a riser extending upwardly from the housing floor, wherein the water filter comprises:
 a filter media cartridge configured to be accommodated inside the filter housing and comprising filter media, wherein the filter media cartridge comprises a cartridge floor spaced above the housing floor, cartridge sidewalls extending upwardly, away from the cartridge floor, and at least one filter media cartridge outlet disposed along one or more of the cartridge floor or the cartridge sidewalls,   wherein, when the filter media cartridge is accommodated inside the filter housing, the riser is spaced between the housing sidewalls and the cartridge sidewalls and extends vertically above the cartridge floor, thereby forming a conduit volume.   
     
     
         2 . The water filter of  claim 1 , further comprising a water outlet flowpath defined from the pour tray to the filter housing outlet, such that the water introduced to the pour tray is operable to enter into the filter media cartridge, exit the filter media cartridge into the conduit volume, and then pass over the riser before exiting the filter housing via the at least one filter housing outlet. 
     
     
         3 . The water filter of  claim 1 , wherein the riser and the housing floor form the conduit volume. 
     
     
         4 . The water filter of  claim 1 , wherein the riser and the cartridge floor form the conduit volume. 
     
     
         5 . The water filter of  claim 4 , wherein the riser is configured to be attached to the cartridge sidewalls by at least one rib. 
     
     
         6 . The water filter of  claim 1 , further comprising a cavity disposed between the housing sidewalls and the cartridge sidewalls, wherein the cavity is configured to be in fluid communication with the conduit volume. 
     
     
         7 . The water filter of  claim 1 , wherein the filter media comprises a permeable membrane located adjacent to the cartridge floor and loose fill filtration media adjacent to the permeable membrane and the cartridge sidewalls. 
     
     
         8 . The water filter of  claim 1 , wherein the filter media cartridge is coupled to the filter housing to form a water-tight seal between the pour tray and the filter media cartridge, and is configured such that water introduced to the pour tray exits through the at least one filter media cartridge outlet. 
     
     
         9 . The water filter of  claim 1 , wherein the filter media cartridge further comprises a retention lip that extends in a radial direction outward from the cartridge sidewalls. 
     
     
         10 . The water filter of  claim 9 , wherein the retention lip is operable to interlock with the pour tray. 
     
     
         11 . The water filter of  claim 9 , wherein the retention lip of the filter media cartridge comprises at least one key, and is configured such that when the filter media cartridge is accommodated in the filter housing, the at least one key is operable to engage at least one keyway of the pour tray. 
     
     
         12 . The water filter of  claim 11 , wherein the filter media cartridge is rotatable within the filter housing and is configured such that when the at least one key engages the at least one keyway and the filter media cartridge forms a water-tight seal with the pour tray, that water introduced to the pour tray exits through the at least one filter media cartridge outlet. 
     
     
         13 . A water filter pitcher comprising:
 a pitcher body comprising a pitcher floor and pitcher sidewalls extending from the pitcher floor; and   a pour tray coupled to the pitcher body, the pour tray comprising:
 a pour tray floor; 
 pour tray sidewalls extending upwards from the pour tray floor; 
 a filter housing extending below the pour tray floor, the filter housing comprising a housing floor, housing sidewalls extending between the housing floor and the pour tray floor, and at least one filter housing outlet disposed along one of more of the housing floor or the housing sidewalls; 
 a filter media cartridge disposed inside the filter housing and comprising filter media, wherein the filter media cartridge further comprises a cartridge floor spaced above the housing floor, cartridge sidewalls extending upwardly, away from the cartridge floor, and at least one filter media cartridge outlet disposed along one or more of the cartridge floor or the cartridge sidewalls; and 
 a riser extending upwardly from the housing floor and spaced between the housing sidewalls and the cartridge sidewalls, wherein the riser extends vertically above the cartridge floor, the riser forming a conduit volume. 
   
     
     
         14 . The water filter pitcher of  claim 13 , further comprising a water outlet flowpath defined from the filter media cartridge outlet to the filter housing outlet, and configured such that the water exiting the filter media cartridge must exit via the at least one filter media cartridge outlet into the conduit volume and then pass over the riser before exiting the filter housing via the at least one filter housing outlet. 
     
     
         15 . The water filter pitcher of  claim 13 , wherein a vertical distance from the pitcher floor to the at least one filter housing outlet is less than about 50% of a vertical distance that the pitcher sidewalls extend from the pitcher floor. 
     
     
         16 . The water filter pitcher of  claim 13 , wherein the riser extends from the housing floor, the riser and the housing floor forming the conduit volume. 
     
     
         17 . The water filter pitcher of  claim 13 , wherein the riser extends from the cartridge floor, the riser and the cartridge sidewalls forming the conduit volume. 
     
     
         18 . The water filter pitcher of  claim 13 , further comprising further comprising a diffusion tray located below the at least one filter housing outlet, the diffusion tray comprising a diffusion tray floor comprising a plurality of depressions that form an undulating surface, and a plurality of weep holes passing through the diffusion tray floor at locations corresponding to at least one of the depressions, wherein the diffusion tray is configured such that water exiting from the at least one filter housing outlet is directed to the depressions and passes through the plurality of weep holes. 
     
     
         19 . A method of maintaining wetness of a filter media cartridge, comprising:
 providing a water filter pitcher comprising:
 a filter housing comprising a housing floor, housing sidewalls vertically extending from the housing floor, and at least one filter housing outlet disposed in the housing floor adjacent to one or more of the housing sidewalls; 
 a filter media cartridge disposed inside the filter housing and comprising filter media, wherein the filter media cartridge comprises a cartridge floor spaced above the housing floor, cartridge sidewalls extending upwardly, away from the cartridge floor, and at least one filter media cartridge outlet disposed in one or more of the cartridge floor or the cartridge sidewalls; 
 a riser extending upwardly, away from the housing floor and spaced between the housing sidewalls and the cartridge sidewalls, wherein the riser extends a vertical distance above the cartridge floor, the interior of the riser forming a conduit volume; and 
 a water outlet flowpath defined from the filter media cartridge outlet to the filter housing outlet, such that the water exiting the filter media cartridge must exit via the at least one filter media cartridge outlet into the conduit and then pass over the riser before exiting the filter housing via the at least one filter housing outlet; 
   introducing water to the water filter pitcher;   passing water into the filter media cartridge;   filtering water with the filter media;   allowing water to exit the filter media cartridge through at least one filter media cartridge outlet;   pooling water in the conduit volume to wet at least a portion of the filter media cartridge; and   displacing water over the riser and through the at least one filter housing outlet.   
     
     
         20 . The method of  claim 19 , wherein depth of the pool corresponds with a vertical distance the riser extends above the cartridge floor. 
     
     
         21 . The method of  claim 19 , wherein the riser extends from the housing floor, and the riser and the housing floor together form the conduit volume. 
     
     
         22 . The method of  claim 19 , wherein the riser extends from the cartridge floor, the riser and the cartridge floor forming the conduit volume.