Apparatus for water purification

1. An apparatus for water purification comprising

a flexible, collapsible water container ( 2 a , 2 b ) comprising a container wall ( 22 , 26 ) made of a flexible sheet material, the container ( 2 a , 2 b ) comprising a water inlet ( 25 ) at a top and a water outlet at a bottom ( 22 ) of the container ( 2 a , 2 b );

a flexible tube ( 3 ) comprising a first end ( 5 ) and a second end ( 9 ) and with a length of at least 30 cm between the first end ( 5 ) and the second end ( 9 ); wherein the first end ( 5 ) is connected to a water outlet ( 60 );

a water purification unit ( 4 ) that is connected to the second end ( 9 ) of the tube ( 3 ) for receiving water from the container ( 2 a , 2 b ) via the tube ( 3 ); the purification unit ( 4 ) comprising purifying media ( 16 ) configured for purifying water through removal of bacteria and sub-micron particles by gravity-forced flow of water through the water purification unit ( 4 );

further comprising a pre-filter chamber ( 23 ) provided at the bottom ( 22 ) of the flexible, collapsible container ( 2 a , 2 b ); the pre-filter chamber ( 23 ) comprising an opening towards the interior of the flexible, collapsible water container ( 2 a , 2 b ), the opening being in fluid-flow communication with a pre-filter material ( 32 ) in the pre-filter chamber ( 23 ) for pre-filtering the water prior to entering the tube ( 3 ); the pre-filter material having a porosity of a predetermined limit preventing particles larger than the predetermined limit to pass the pre-filter material ( 32 ) but allowing smaller particles to pass through the pre-filter material ( 32 ) and into the tube ( 3 );

wherein the predetermined limit is a specific size selected from the interval of 10 to 120 microns, wherein a lateral extension of the pre-filter chamber ( 23 ) is smaller than the lateral extension of bottom ( 22 ) of the container ( 2 a , 2 b ), and wherein the opening ( 30 ) of the pre-filter chamber is provided only at a height of between 1 and 5 cm above the bottom ( 22 ) of the container ( 2 a , 2 b ), thereby providing a volume around the pre-filter chamber ( 23 ) at the bottom ( 22 ) for collecting water with impurities at the bottom ( 22 ) without the impurities having access to the opening ( 30 ).

2. An apparatus for water purification comprising:

a flexible, collapsible water container ( 2 a , 2 b ) comprising a container wall ( 22 , 26 ) made of a flexible sheet material, the container ( 2 a , 2 b ) comprising a water inlet ( 25 ) at a top and a water outlet at a bottom ( 22 ) of the container ( 2 a , 2 b );

a flexible tube ( 3 ) comprising a first end ( 5 ) and a second end ( 9 ) and with a length of at least 30 cm between the first end ( 5 ) and the second end ( 9 ); wherein the first end ( 5 ) is connected to a water outlet ( 60 );

a water purification unit ( 4 ) that is connected to the second end ( 9 ) of the tube ( 3 ) for receiving water from the container ( 2 a , 2 b ) via the tube ( 3 ); the purification unit ( 4 ) comprising purifying media ( 16 ) configured for purifying water through removal of bacteria and sub-micron particles by gravity-forced flow of water through the water purification unit ( 4 );

further comprising a pre-filter chamber ( 23 ) is provided at the bottom ( 22 ) of the flexible, collapsible container ( 2 a , 2 b ); the pre-filter chamber ( 23 ) comprising an opening towards the interior of the flexible, collapsible water container ( 2 a , 2 b ), the opening being in fluid-flow communication with a pre-filter material ( 32 ) in the pre-filter chamber ( 23 ) for pre-filtering the water prior to entering the tube ( 3 ); the pre-filter material having a porosity of a predetermined limit preventing particles larger than the predetermined limit to pass the pre-filter material ( 32 ) but allowing smaller particles to pass through the pre-filter material ( 32 ) and into the tube ( 3 );

wherein the predetermined limit is a specific size selected from the interval of 10 to 120 microns, wherein a lateral extension of the pre-filter chamber ( 23 ) is smaller than the lateral extension of bottom ( 22 ) of the container ( 2 a , 2 b ), and wherein the opening ( 30 ) of the pre-filter chamber is provided only at a height of between 1 and 5 cm above the bottom ( 22 ) of the container ( 2 a , 2 b ), thereby providing a volume around the pre-filter chamber ( 23 ) at the bottom ( 22 ) for collecting water with impurities at the bottom ( 22 ) without the impurities having access to the opening ( 30 ), wherein the pre-filter chamber ( 23 ) comprises a rigid base ( 29 ) and a rigid cap ( 28 ) mutually connected to form an interior volume ( 33 ) inside the pre-filter chamber ( 23 ); wherein the cap ( 28 ) forms a ceiling of the interior volume ( 33 ) and is provided inside the flexible container bag ( 2 a , 2 b ); and wherein the cap ( 28 ) is provided manually removable from the base ( 29 ) for manual access to the pre-filter material ( 32 ); wherein the base ( 29 ) is attached irremovably to the container wall ( 26 ) at the bottom ( 22 ) of the flexible container ( 2 a , 2 b ) by a water tight glued or welded connection ( 38 ); wherein the base ( 29 ) comprises a connector unit ( 21 ) to which the tube ( 3 ) is connected for flow of water from the interior volume ( 23 ) of the pre-filter chamber ( 23 ) through the connector unit ( 21 ) into the tube ( 3 ).

3. An apparatus according to claim 2 , wherein the cap ( 28 ) is provided with the opening and wherein the opening is covered by the pre-filter material ( 32 ) for pre-filtering the water prior to flow into the interior volume ( 33 ) of the pre-filter chamber ( 23 ).

4. An apparatus according to claim 3 , wherein the cap ( 28 ) has an upper side that is provided with a plurality of openings and an underside of the cap that is covered by the pre-filter material ( 32 ), which is a sheet of fabric or paper extending laterally across the cap.

5. An apparatus according to claim 2 , wherein the interior volume ( 33 ) of the pre-filter chamber ( 23 ) is formed as a torus confined by a pre-filter chamber bottom ( 41 ), a central tubular elevation ( 42 ) extending upwards from the pre-filter chamber bottom ( 41 ), and an upstanding wall ( 39 ) extending upwards from the pre-filter chamber bottom ( 41 ) and surrounding the central tubular elevation ( 42 ), and the torus being further confined by the cap ( 28 ) which in combination with the pre-filter material is forming the ceiling for the interior volume ( 33 ) of the pre-filter chamber ( 23 ); wherein the central tubular elevation ( 42 ) is fluid-flow connected to the connector unit ( 21 ) or is part of the connector unit ( 21 ) for flow of water from the interior volume ( 33 ) through the central tubular elevation ( 42 ) and through the connector unit ( 21 ) into the tube ( 3 ).

6. An apparatus according to claim 5 , wherein the interior volume ( 33 ) has a height H from a bottom of the pre-filter to the cap ( 28 ), and wherein a quick connector unit ( 21 ) in combination with the central tubular elevation ( 42 ) comprises an inlet ( 43 ) for receiving pre-filtered water from the interior volume ( 33 ), the inlet ( 43 ) being provided at a distance D from the cap, the distance being less than 20% of H.

7. An apparatus according to claim 2 , wherein a quick connector unit ( 21 ) is fastened to the pre-filter chamber ( 23 ), the quick connector unit ( 21 ) comprising a central channel ( 40 ) with a resiliently operated snap-lock ( 50 , 51 ) for receiving and fixing a cooperating quick connector at the first end ( 5 ) of the tube ( 3 ) inside the central channel ( 40 ).

8. An apparatus according to claim 2 , wherein the interior volume ( 33 ) of the pre-filter chamber ( 23 ) contains a granular purification material comprising at least one of the following: activated carbon, ion exchange resin, zeolites, ferrous hydroxide, ferric oxide, activated alumina.

9. An apparatus according to claim 8 , wherein the interior volume ( 33 ) comprises a cartridge ( 53 ) with the granular purification material ( 52 ), the cartridge comprising a water impermeable top wall ( 54 ), a water permeable side wall ( 55 ) extending across the pre-filter material ( 32 ) for guiding the water from the openings ( 31 ) in the cap ( 28 ) and from the pre-filter material ( 32 ) towards a side wall and around the cartridge ( 53 ) for water flow ( 56 ) through the granular material ( 52 ) prior to entering the water outlet ( 60 ).