Gravity-flow filtration cartridge for the removal of microorganisms and/or other contaminants

A filter cartridge for use in a gravity-flow filtration unit for removing water-borne parasites from water, the filter cartridge comprising:

• a housing having a container and a cover, wherein said container comprises a top end, a bottom end, a sidewall having at least one air vent wherein said sidewall has an inner surface defining an inner space, an opening near the container top end for access to the inner space, a water outlet near the container bottom end, and wherein said cover covers said container opening and has a central axis, an outer flange, and a water inlet perforating cover near said central axis;
• and
• an open-topped filter cup received in the inner space of said housing body inner space and having a cup wall comprising a generally vertical cup sidewall and a cup bottom wall positioned near the container bottom end, said cup wall having an interior surface in fluid communication with the cover water inlet and defining a cup interior space and an outer surface in fluid communication with said housing container water outlet, said cup wall comprising a porous plastic layer 0.15-0.50 inch thick and having pores with a median pore size in the range of 10-20 microns for allowing flow of water through the pores of said porous plastic layer under force of gravity and for retaining parasites in said porous plastic layer;
• and
• wherein said container sidewall has a plurality of protrusions extending radially inward from the container wall inner surface and contacting and frictionally engaging said cup sidewall outer surface, for securing said filter cup in said housing;
• whereby unfiltered water flows through the cover water inlet, into said filter cup interior space though said filter cup wall, and out of said housing through said housing container water outlet.

A filtration system for removing inorganic and organic contaminants from drinking water, comprising:

• a filter cartridge;
• a filtration unit comprising an upper reservoir for receiving unfiltered water, a lower reservoir for receiving filtered water, a support means for supporting said filter cartridge near a bottom area of said upper reservoir;
• wherein said filter cartridge comprises:
• a housing having a top, a bottom, a sidewall, a housing inner space, at least one air vent in said sidewall near said top, a water inlet near said top and a water outlet near said bottom;
• and
• a filter received in said housing inner space, the filter comprising a porous plastic layer having an inlet side, an outlet side, and pores with a median pore size in the range of 10-20 microns which form a matrix of tortuous pathways for retaining water-borne parasites;
• wherein said inlet side of the porous plastic layer is in fluid communication with the housing water inlet and said outlet side of the porous plastic layer is in fluid communication with the housing water outlet wherein gravity is the only force used to pull the unfiltered water from the upper reservoir, through the housing water inlet, the porous plastic layer, and the housing water outlet, to the lower reservoir.

A filter cartridge for use in a gravity-flow filtration unit for removing water-borne parasites from water, the filter cartridge comprising:

• a housing having a body and a cap, the body having a top end, a bottom end, a body sidewall with an inner surface defining an inner space, an opening near the body top end for access to the inner space, an opening near the body top end for access to the inner space, and an outlet near the body bottom end, and wherein said cap covers said body top end and has a central axis, an outer flange, and a water inlet perforating said cap near said central axis, and
• an open-topped filter cup having a cup wall comprising a cup sidewall and a cup bottom wall positioned near said body bottom end, said cup wall having an interior surface in fluid communication with said housing body water outlet, said cup wall comprising a porous plastic layer 0.25-0.50 inch thick and having pores with an average pore size in the range of 10-20 microns for allowing flow of liquid through the pores of the porous plastic layer under force of gravity and for retaining parasites in the porous plastic layer;
• and
• wherein the body sidewall comprises an air vent and a plurality of protrusions extending radially inward from the body sidewall inner surface contacting and frictionally engaging said cup sidewall outer surface, for securing said filter cup in said housing body;
• whereby unfiltered liquid flows through said cap water inlet, into the filter cup interior space, through the filter cup wall, and out of the housing through the housing body water outlet.