WATER FILTRATION DEVICE WITH SEQUENTIAL BACKWASH AND METHOD OF ITS OPERATION

Abstract

Disclosed is a water filtration device which includes various hoses for connection between different parts of the filtration device and a rotatable cam system which, during backwash cycles, is rotated so as to clamp various the hoses in predetermined sequences for thereby controlling the direction of the flow of water through the tubing system. Electrical pinch valves are use alternatively to a cam shaft.

Claims

1. A water filtration device comprising a dirt water inlet for receiving dirt water for filtration; a clean water outlet for dispensing of filtered water for consumption; a backwash water outlet for release of backwash water from the device; a panel for user operation of the device, wherein the panel comprises a switch for switching between on and off for filtration of water; a filtration system for filtering dirt water from the dirt water inlet and for providing clean water to the clean water outlet; the filtration system comprising a first water filter; a tubing system with a plurality of hoses connecting the dirt water inlet and the clean water outlet with the filtration system, the plurality of hoses comprising a backwash hose in a flow path from the filtration system to the backwash outlet for backwash water release from the device through the backwash hose and through the backwash outlet during backwash of the filtration system when the device is in backwash mode; the plurality of hoses comprising a clean water hose in a flow path from the filtration system to the clean water outlet for release of clean water from the device when the device is in filtration mode; a multi flow arrangement with a plurality of compartment through which said plurality of hoses extend, wherein each of the compartments comprises a clamping function for closing one of the plurality of hoses extending through the corresponding compartment by clamping it; wherein the device is configured for activating the clamping function of the compartments in the multi flow arrangement sequentially for closing the hoses in accordance with a predetermined sequence for shifting between the filtration mode and the backwash mode.

2. The device according to claim 1, wherein the panel is functionally connected to the clamping function for operating the clamping function in the multi flow arrangement by user operation; wherein the activation of the clamping function is configured to be caused by the user operation from the panel.

3. The device according to claim 1, wherein the filtration system comprises a second water filter, wherein the device is configured for filtering of water by the second water filter and supply this filtered water in reverse flow through the first water filter for backwashing the first water filter during filtration of the water by the second water filter and with the water filtered by the second water filter, and wherein the device is configured for filtering of water by the first water filter and supply this filtered water in reverse flow through the second water filter for backwashing the second water filter during filtration of the water by the first water filter and with the water filtered by the first water filter; wherein the device is configured for a corresponding backwash flush sequentially, as part of the predetermined sequence, from the filtration mode for normal water filtration by both water filters to a first backwash mode with backwash of the first water filter with filtered water from the second water filter, and to a second backwash mode with backwash of the second water filter with filtered water from the first water filter.

4. The device according to claim 3, wherein the wherein device further is configured for forward flush as part of the predetermined sequence from the first backwash mode to a first forward flush mode with forward flush of the first water filter, from the second backwash mode to a second forward flush mode with forward flush of the second water filter.

5. The device according to claim 1, comprising a pressure regulator in a flow path between the dirt water inlet and the filtration system for limiting the pressure to below a predetermined value for preventing damage to the filtration system due to overpressure, wherein the predetermined value is in the range of 0.2 to 2 bar above ambient atmospheric pressure.

6. The device according to claim 5, wherein the switch in the off-state is configured for causing blockage of water flow at a position in the flow path between the pressure regulator and the filtration system.

7. The device according to claim 6, wherein a dirt water hose is provided in a dirt water flow path between the pressure regulator and the filtration system, and wherein the switch comprises a clamp for clamping the dirt water hose and for preventing flow through the dirt water hose when the clamp is activated in the off-state of the switch.

8. The device according to claim 1, wherein the device is a portable device with a weight in the range of 5 to 20 kg; the device comprising a casing, and wherein the dirt water inlet, the backwash water outlet, the filtration system, the hoses, and the multi flow arrangement, are provided in the casing.

9. The device according to claim 1, wherein the clamping function for each compartment comprises an electrical pinch valve activatable in accordance with the predetermined sequence by at least one of: corresponding user operation on the panel, automatic activation determined by a timer after a predetermined time lapse, and automatic activation after dispensing of a predetermined volume of filtered water.

10. The device according to claim 9, comprising a pinch valve controller configured for receiving user command from the panel and upon user command activating the pinch valves of the multi flow arrangement by automatic clamping in accordance with the predetermined sequence for automatically shifting between the filtration mode and the backwash mode upon user command.

11. The device according claim 1, wherein the device comprises a cam shaft that is rotatable with respect to a rotation axis and with multiple cams provided in parallel planes perpendicular to the rotation axis on the cam shaft for rotation therewith, each of the multiple cams being arranged for activating the clamping function in one of the compartments when attaining a predetermined individual angular clamping position during rotation of the cam shaft; wherein the cams are provided at different angular locations of the cam shaft for closing the hoses in the compartments in accordance with the predetermined sequence, when the cam shaft is rotated, and for shifting between a filtration mode of the device to a backwash mode for backwash of the filtration system by the rotation.

12. The device according to claim 11, wherein the device is configured for a corresponding backwash flush sequence by turning the cam shaft in steps from a first orientation for normal water filtration by both water filters to a second orientation in a first backwash mode with backwash of the first water filter with filtered water from the second water filter, and to a further orientation in a second backwash mode with backwash of the second water filter with filtered water from the first water filter.

13. The device according to claim 12, wherein the wherein device is configured for a backwash and forward flush sequence by turning the cam shaft in steps after the second orientation further to a third orientation in a first forward flush mode with forward flush of the first water filter, and further to a fourth orientation in the second backwash mode with backwash of the second water filter with filtered water from the first water filter, and further to a fifth orientation in the second forward flush mode with forward flush of the second water filter.

14. The device according claim 1, wherein the panel comprises a manually rotatable handle that is functionally connected to the clamping function for operating the clamping function in the multi flow arrangement by manual rotation of the handle, the manual rotation of the handle in a single direction causing the sequential closing and opening of the hoses in accordance with the predetermined sequence for shifting between the filtration mode and the backwash mode.

15. The device according to claim 14, wherein the switch comprises a blocking member for blocking rotation of the handle when the switch is in the off-state.

16. The device according to claim 1, wherein the first water filter comprises a first water inlet at an up-stream side of the first water filter for receiving water for filtration by the first water filter and a first water outlet at a downstream side of the first water filter for delivering water filtered by the first water filter, wherein the first water filter has a water flow direction during filtration from the upstream to the downstream side and a water flow direction during backwash from the downstream side to the upstream side; wherein tubing system comprises a first inflow hose connected to the first water filter and provided as part of a water flow path from the dirt water inlet to the first water inlet for flow of water through the first inflow hose to the first water inlet; a clean water hose connected to the first water outlet for receiving filtered water from the first water filter; a first backwash hose connected between the backwash water outlet and the upstream side of the first water filter for flow of backwash water from the first water filter to the backwash water outlet during backwash of the first water filter; wherein the device in a first filtration mode is configured for clamping and closing the first backwash hose in the multi flow arrangement by activating clamping on the first backwash hose in one of the compartments while maintaining flow through the inflow hose and the clean water hose; wherein the device in a first backwash mode is configured for clamping and closing the first inflow hose in the multi flow arrangement by activating clamping on the first inflow hose in another one of the compartments while maintaining flow in the multi flow arrangement in reverse through the clean water hose and flow through the first backwash hose.

17. The device according to claim 16, wherein the first water filter also comprises a first flush outlet at the upstream side of the first water filter for release of water during forward flush with a water flow into the first water inlet through the first water filter and out of the first flush outlet for forward flushing along the upstream side inside the first water filter; wherein the first backwash hose is connected to the first flush outlet; wherein the device further comprises a first forward flush mode; wherein the device in the first forward flush mode is configured for clamping and closing the clean water hose for preventing filtered water flow from the first water filter into the clean water hose, and for maintaining flow in the multi flow arrangement through the first inflow hose and the first backwash hose for flow of water from the first inflow hose into the first water filter through the upstream side of the first water filter, and out of the first water filter through the first flush outlet.

18. The device according to claim 1, wherein the filtration system comprises a second water filter for filtering dirt water and for providing filtered water; the second water filter comprising a second water inlet at an upstream side of the second water filter for receiving water for filtration by the second water filter and a second water outlet at a downstream side of the second water filter for delivering water filtered by the second water filter, wherein the second water filter has a water flow direction during filtration from its upstream to its downstream side and a water flow direction during backwash from its downstream side to its upstream side; wherein the clean water hose is also connected to the second water outlet for receiving filtered water from the second water filter; wherein the device, in the first backwash mode, is configured for filtration of water by the second water filter and supply of this filtered water to the clean water hose and from the clean water hose in reverse flow through the first water filter for backwashing the first water filter with the water filtered by the second water filter during filtration of the water by the second water filter.

19. The device according to claim 8, wherein the device further comprises: a second inflow hose connected to the second water filter and provided as part of a flow path from the dirt water inlet to the second water inlet for flow of water from the dirt water inlet through the second inflow hose to the second water inlet; a second backwash hose connected between the backwash water outlet and the upstream side of the second water filter for flow of backwash water from the second water filter to the backwash release during backwash of the second water filter; wherein the second inflow hose and the second backwash hose extend through corresponding compartments in the multi flow arrangement; wherein the device in the first filtration mode is configured for clamping and closing the second backwash hose in the multi flow arrangement by activating clamping the second backwash hose in the corresponding compartments while maintaining flow in the multi flow arrangement through the second inflow hose and the clean water hose; wherein the device in the first backwash mode is configured for clamping and closing the second backwash hose of the second water filter in the multi flow arrangement while maintaining flow in the multi flow arrangement through the second inflow hose and maintain filtration of water by the second water filter and flow thereof into the clean water tube and further in reverse into the first water filter.

20. A method for operating a water filtration device, the device comprising a dirt water inlet for receiving dirt water for filtration; a clean water outlet for dispensing of filtered water for consumption; a backwash water outlet for release of backwash water from the device; a panel for user operation of the device, wherein the panel comprises a switch for switching between on and off for filtration of water; a filtration system for filtering dirt water from the dirt water inlet and for providing clean water to the clean water outlet; the filtration system comprising a first water filter; a tubing system with a plurality of hoses connecting the dirt water inlet and the clean water outlet with the filtration system, the plurality of hoses comprising a backwash hose in a flow path from the filtration system to the backwash outlet for backwash water release from the device through the backwash hose and through the water outlet during backwash of the filtration system when the device is in backwash mode; the plurality of hoses comprising a clean water hose in a flow path from the filtration system to the clean water outlet for release of clean water from the device when the device is in filtration mode; a multi flow arrangement with a plurality of compartment through which said plurality of hoses extend, wherein each of the compartments comprises a clamping function for closing one of the plurality of hoses extending through the corresponding compartment by clamping it; wherein the method comprises: activating the clamping function of the compartments in the multi flow arrangement sequentially; and closing and opening the hoses for flow in accordance with a predetermined sequence for shifting between the filtration mode and the backwash mode.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0095] The invention will be explained in more detail with reference to the drawing, where

[0096] FIG. 1 shows a portable filtration device according to the invention;

[0097] FIG. 2 shows an arrangement with serial connection between four filtration devices;

[0098] FIG. 3A shows the interior of a filtration device with two water filters;

[0099] FIG. 3B shows the interior of a filtration device with two water filters and a decontamination stage;

[0100] FIG. 4A illustrates some components inside the filtration device;

[0101] FIG. 4B Illustrates the interior with details of the tubing of the filtration device;

[0102] FIG. 4C illustrates a different view of the interior of the device;

[0103] FIG. 4D illustrates the interior of the device when a decontamination stage is added;

[0104] FIG. 5 illustrates a cam controller;

[0105] FIG. 6 is a side view of the cam controller;

[0106] FIG. 7A illustrates the switch when in a filtration mode;

[0107] FIG. 7B illustrates the switch when not in filtration mode and blocking the upper handle from rotation;

[0108] FIG. 7C illustrates the switch when not in filtration mode and when partially squeezing the first hose by the lever;

[0109] FIG. 7D illustrates the switch when not in filtration mode and when fully squeezing the first hose by the lever;

[0110] FIG. 8A illustrates a first of four steps of the cam driver;

[0111] FIG. 8B illustrates a first of four steps of the cam driver;

[0112] FIG. 8C illustrates a first of four steps of the cam driver;

[0113] FIG. 8D illustrates a first of four steps of the cam driver;

[0114] FIG. 8E shows an enlarged part of FIG. 8A;

[0115] FIG. 9A is a flow illustration through the hoses;

[0116] FIG. 9B illustrates the flow in filtration mode;

[0117] FIG. 9C illustrates the idle state;

[0118] FIG. 9D illustrates a first backwash mode for backwashing the first water filter;

[0119] FIG. 9E illustrates a first forward flush mode for flushing the first water filter;

[0120] FIG. 9F illustrates a second backwash mode for backwashing the second water filter;

[0121] FIG. 9G illustrates a second forward flush mode for flushing the second water filter;

[0122] FIG. 10 illustrates an alternative embodiment with pinch valves;

[0123] FIG. 11 illustrates a further alternative embodiment with a pinch valve on the dirt water hose.

DETAILED DESCRIPTION/PREFERRED EMBODIMENT

[0124] FIG. 1 illustrates a filtration device 1 that comprises a casing 2 with a demountable lid 3 that is held by a plurality of detachable clamps 4. In the current embodiment, the clamps are slidable, and a locking mechanism depends on the position of the clamp as the clamps lock the lid 3 to the lower part of the casing 2 in one position and release it in another position.

[0125] A cartridge access cap 5 is integrated in the lid 3 and can be unscrewed from the lid 3 for giving access to a pre-filter cartridge. The front panel 2A of the casing 2 comprises a tap 6, a switch 7 and a manually operated rotational handle 8A, for example for rotationally driving a cam driver 8 by rotating the handle 8A. An example thereof is explained in more detail below, where also alternatives to the cam driver 8 are discussed and where the handle 8A is explained to be applicable for controlling electrical pinch valves as alternatives to a cam driver 8.

[0126] The tap 6 is configured for dispensing filtered water when the device 1 is in filtration mode. The switch 7 is used to regulate the dispensing of water.

[0127] In the case of an embodiment with a cam driver 8, the handle 8A is used for driving a cam shaft 20 and for regulation of a backwash sequence. The functions of the switch 7 and the cam driver 8 will be explained in greater detail below.

[0128] As a further alternative, the cam 20 driven by a motor, which is not illustrated, however. Although, the device 1 is illustrated and explained in the following with a manual cam driver 8, it is understood that the driving of the cam 20 could alternatively be performed by an automated electrical motor.

[0129] FIG. 2 shows an arrangement with parallel connection of 4 identical filtration devices 1. The taps 6 at the front panel 2A are connected for supplying filtered water through a common dispenser tube 6′. Each of the devices 1 has a dirt water inlet 10 and a backwash water outlet 11. The dirt water inlets 10 of the four devices 1 are connected to a common water supply tube 12 for supplying dirt water for filtering, for example from a supply pump (not shown). The backwash water outlets 11 are connected to a common release tube 13 for release of backwash water through the release tube 13. By connecting the filtration devices 1 in parallel with a common water supply tube 12, the capacity can be increased in a simple manner, for example in emergency situations where a large capacity of water is requested but only few water supply sources available.

[0130] FIG. 3A illustrates some of the components in the interior of the device 1 when the lid 3 is removed. Notice that not all of the internal components of the device 1 are shown for the sake of giving a better overview. Visible in FIG. 3A is a pre-filter housing 9 without the cartridge access cap 5 so that there is given access to a pre-filter cartridge with three pre-filter elements 9A, 9B, 9C having decreasing pore size from the inner first filter element 9A to the second filter element 9B and then to the third filter element 9C inside the pre-filter housing 9. Downstream of the dirt water inlet 10, a pressure regulator 14 regulates the water pressure to below a predetermined maximum level inside the device 1 in order to prevent damage to the components inside the device 1. For example, the pressure is regulated to a predetermined pressure level that has a fixed value within the range of 0.2 to 2 bar above ambient pressure.

[0131] As illustrated in FIG. 3a, two microporous water filters 15A and 15B are provided for microfiltration or ultrafiltration inside the casing 2.

[0132] As illustrated in FIG. 3b, optionally also a third cartridge 16 is provided, which is a decontamination stage for decontamination of chemical contaminants, configured in accordance with the type of contaminants that are to be removed, typically by absorption or adsorption, for example lead, arsenic, iodine and/or chlorine. For examples an activated-carbon filter is provided in the third cartridge 16 in order to remove chemicals, for example iodine or chlorine, prior to consumption, especially if added to the water for reducing germ content. Other options are resins that remove lead or arsenic. Whereas the water filters 15A, 15B can be used in parallel, the activated-carbon filter 16 would typically be used serially, downstream of the water filters 15A, 15B.

[0133] The filtered water from the water filters 15A and 15B enters a common connector, which is exemplified as a tubular bar 36. As illustrated in FIG. 3a, the filtered water exits the tubular bar 36 at bar connection 36A and enters a clean water hose 24 which leads the filtered water to the tap 6. In the alternative embodiment of FIG. 3b, the filtered water exits the tubular bar 36 at bar connection 36A and enters from there directly the decontamination stage 16 and gets decontaminated, after which the water exits the decontamination stage 16 at its top and enters clean water hose 24.

[0134] As seen in FIG. 3a, a cam shaft 20 with cams 20A is provided for activating valves in a multi flow arrangement 17.

[0135] FIGS. 5 and 6 illustrate the function of the cam shaft 16. A multi flow arrangement 17 comprises multiple pairs of axially aligned apertures 18A, 18B on either end of the corresponding compartment 17A of the multi flow arrangement 17, through which hoses 21 are extending, typically pushed through these apertures. For each pair of apertures 18A, 18B, there is provided a lever 19 that is operated by one of the cams 20A on the cam shaft 20 in dependence of the rotational orientation of the cam shaft 20. When the cam shaft 20 is rotated, one of the cams 20A presses the lever 19 onto the respective hose for a certain angular orientation of the cam shaft 20, so that the moving end 19A of the lever 19 squeezes part 21A of the hose 21 in the compartment 17A, as illustrated in FIG. 6. By changing the rotational orientation of the cam shaft 20, various differently arranged cams 20A press onto various corresponding levers 19 in dependence on the rotational angular position of the cam shaft 20A. By adjusting the angular orientation of the cam shaft 20, the water flows through the various hoses 21 that extend through the pairs 18A, 18B of apertures are controlled and changed.

[0136] In particular, the cam shaft 20 and the respective cams 20A are configured for stepwise change from normal filtering mode of the device 1 through a backwash sequence, and back to normal filtering mode. This will be explained in greater detail below after an explanation of the tubing inside the device 1.

[0137] FIG. 4A illustrates some of the tubing inside the device casing 2. From the dirt water inlet 10, pressurized dirt water enters the pressure regulator 14, which limits the pressure to below a pre-set upper limit, for example to less than 2 bar, for example less than 1 bar or less than 0.5 bar, above ambient pressure, in order to protect the device 1 and its components against breakage because of overpressure. The dirt water downstream of the pressure regulator 14 flows into dirt water hose 22. It is pointed out that the tubing for the optional decontamination stage for examples carbon-filter 16 is not shown in FIG. 4A but in FIG. 4D.

[0138] FIG. 4b illustrates the configuration of the dirt water hose 22. It is positioned in and along a canal 35 around the switch 7. After the canal 35, the dirt water hose 22 bends up to the pre-filter housing 9 where the water flows through pre-filter housing 9 in for removal of particular matter by the pores in the pre-filter, for example particular matter with a grain size above 10 microns.

[0139] As best shown in FIG. 4A, the pre-filtered water leaves the pre-filter housing 9 through pre-filter outlet into a first water inflow hose 23A for water filter 15A and a second water inflow hose 23B to second water filter 15B. FIG. 4A also illustrates the inflow hoses 23A, 23B bending from the pre-filter 9 through the multi flow arrangement 17 and down to the bottom of the first and second water filter 15A, 15B.

[0140] FIG. 4B illustrates the inflow hoses 23A, 23B extending from the multi flow arrangement 17 to water filter inlets 26A, 26B. After filtration, for example microfiltration, the filtered water leaves the water filters 15A, 15B through clean water outlets 27A, 27B and into tubular cross bar 36. FIG. 4A illustrates a clean water hose 24 being connected to the connector 36A of the tubular cross bar 36 and then extending through the multi flow arrangement 17. FIG. 4B, which illustrates the hose arrangement from the opposite side, shows the clean water hose 24 extending through the multi flow arrangement 17. As further illustrated in FIG. 4B, the clean water hose 24 bends towards the back of the front panel 2A and is connected to the tap 6.

[0141] Accordingly, the flow of water for such circuit is from the dirt water inlet 10, through pressure regulator 14, through the dirt water hose 22, through the canal 35, into the pre-filter 9, from the pre-filter 9 through inflow hoses 23A, 23B into the water filters 15A, 15B, from the water filters 15A, 15B through the tubular bar 36 and, optionally through decontamination stage 16 as shown in FIG. 4D, and through clean water hose 24 and to the tap 6, from which it can be released when the switch 7 is in the on-state orientation.

[0142] The flow through the water tap 6 is regulated by the switch 7 as shown in the semi-transparent illustration of the back side of the front panel 2A in FIG. 7A through D. In the water flow position for the tap 6, the flow though the dirt water hose 22 is not obstructed.

[0143] The switch comprises a first cams 28 and a second cam 38, the different functions of which will be explained in the following. When the switch 7 is rotated, as illustrated in the sequence of FIGS. 7B, 7C, and 7D, the first cam 28 presses a lever 29 onto the dirt water hose 22 in canal 35 in order to squeeze the dirt water hose 22 to a closed position. This implies that the control for the water flow is made by squeezing the dirt water hose 22 between the pressure regulator 14 and the pre-filter 9, thus turning off the pressure on the water filters 15A, 15B ad well as the pressure on the pre-filter 9. This is a safety mechanism for preventing pressure overload on the filters 15A, 15B even in case of a malfunctioning pressure regulator 14. When the switch is turned off, and the connection between the pressure regulator 14 and the pre-filter 9 is inhibited by squeezing of the dirt water hose 22, it is also possible without inlet pressure to perform maintenance of the pre-filter 9 without having to disconnect dirt water hose 22.

[0144] This implies that the path from the tap 6 backwards to the water filters 15A and 15B is not closed by the switch 7. However, in order to prevent contamination from the water tap 6 backwards into the water filters 15A, 15B, a blocking or non-return mechanism, optionally non-return valve, for example a duckbill valve, is advantageously installed between the water filters 15A, 15B and the tap 6, for example between the clean water hose 24 and the tap 6.

[0145] When the switch 7 is rotated, as illustrated in the sequence from FIG. 7B to FIG. 7D, the second cam 38 of the switch 7 enters a recess 30 in the cam driver 8, preventing the cam driver 8 from rotating. As explained in greater detail below, the cam driver 8 is only used for backwash and forward flush, and the blocking function of the rotation of the cam driver 8 when the tap 6 is closed, implies that backwash can only be performed when the water flow through tap 6 is open. In particular, for the user, this would function as follows. The user would keep the switch 7 in the open position where flow of water occurs through the tap 6. This indicates to the user that there is pressure on the system and water flow through the filters 9, 15A, 15B and out of the tap 6. When the cam driver 8 is then turned for backwash, the water flow out of the tap 6 would stop and the water flow would be reversed through the filters 15A, 15B in a sequence as described below, until the backwash cycle has been finished, after which, a renewed flow out of the tap 6 would indicate to the user, that the backwash cycle has been finished. Thus, the flow out of tap 6 prior to rotating the cam driver 8 shows the user the capability of backwash due to the water flow through the system, and the flow out of tap 6 after the backwash cycle indicates to the user that the backwash cycle has ended.

[0146] In order to ease the backwash cycle and prevent mishandling by the user, the cam driver 8 can only be turned in one direction. This is illustrated in the encircled region FIG. 8A and in enlarged illustrating in FIG. 8E, where cooperating grooves and teeth 32 form a one-way ratchet mechanism for the cam driver 8, such that the cam driver 8 after one backwash step can only be proceeded to the next step by a one-way only turning of the cam driver 8.

[0147] By turning the cam driver 8, as illustrated by the sequence of FIGS. 8A, B, C, and D, the cam shaft 20 as illustrated in FIG. 5 and as illustrated in the lower right corner of FIG. 9A is rotated and the various cams 20A in cooperation with corresponding levers 19 open and close the hoses 23A, 23B, 24, 25A, 25B in a predetermined sequence for assuring proper water flow from one component to the other according to a predetermined backwash procedure.

[0148] The cam shaft 20 with the cams 20A and the multi flow arrangement 17 in the lower right corner of FIG. 9A illustrates valves V1, V2, V3, V4, V5 provided as combinations of a cam 20A and lever 19A for a corresponding compartment 17A and which are illustrated throughout FIG. 9A to FIG. 9G. FIG. 9A is an overview of the system as described above with the various component numbers indicated. For the backwash hoses 25A and 25B and the backwash flush outlets 33A and 33B, reference is also made to FIG. 4B, where these components are indicated.

[0149] V1 opens or closes off the clean water hose 24 between the end 36A of the tubular cross bar 36 and the tap 6.

[0150] V2 opens or closes off the second backwash hose 25B between the backwash release 11 and second flush outlet 33B of the second water filter 15B.

[0151] V3 opens or closes off the second inflow hose 23B between the pre-filter 9 and the second water inlet 26B of the second water filter 15B.

[0152] V4 opens or closes off the first backwash hose 25A between the first flush outlet 33A of the first water filter 15A and the backwash release 34.

[0153] V5 opens or closes off the first inflow hose 23A between the pre-filter 9 and the first water inlet 26A of the first water filter 15A

[0154] As illustrated in FIG. 9A, the pre-filter elements 9A, 9B, 9C are shown with a bottom plug 37 plugged into the backwash release 34 for ease of removal and simultaneous emptying of the water in the pre-filter 9. The flushing of the pre-filter is performed by pulling out a pre-filter support to perform cleaning/maintenance of the element 9A, 9B, 9C.

[0155] In the FIGS. 9B through 9G, there are no numerals indicated, however, the terminology and numerals of FIG. 9A will be used.

[0156] FIG. 9B illustrates normal filtering mode and is read in combination with some of the elements illustrates in FIG. 4B and FIG. 7A. The switch 7 is in water filtration orientation and the cam driver 8 in FIG. 9B is in filtration orientation, causing V2 and V4 closed by clamping on the first and second backwash hoses 25A, 25B. The orientation of the cam driver 8 for this mode is indicated in the lower right corner of FIG. 9B. Water enters through the inlet 10 and flows through the pressure regulator 14, through the dirt water hose 22 and the canal 35, as illustrates in FIG. 4B, pass the first cam 28 and lever 29, which are not squeezing the dirt water hose 22 (see FIG. 7A for comparison), and into the pre-filter 9, which contains a pre-filter element 9A, typically with multiple layers 9B, 9C, as illustrated in FIG. 9B when read with the numeral of FIG. 9A.

[0157] From the pre-filter 9, the water flows through inflow hoses 23A, 23B, as already described above and into water inlet 26A, 26B in water filters 15A, 15B, through the filters 15A, 15B, and out of clean water outlets 27A, 27B and into clean water hose 24 and through and out of tap 6. In this mode, as illustrated in FIG. 9B, V2 and V4 are blocked in order to prevent the pre-filtered water from leaving the water filters 15A, 15B through the flush outlets 33A, 33B.

[0158] FIG. 9C illustrates the mode for the idle state of the device 1. The cam driver 8 has been left in orientation for the filtration mode. However, the switch 7 is in closed orientation and blocks for water flowing from the pressure regulator 14 to the pre-filter element 9A and further through the water filters 15A, 15B to the tap 6. In this mode, V2 and V4 are kept blocked to prevent drying out of the water filters 15A, 15B during longer storage. The function of the switch 7 on the dirt water hose 22 was explained in relation to FIG. 7D. In this idle state, it is safe to open the cartridge access cap 5 in order to access pre-filter support 9D and the interconnected pre-filter 9A, 9B and 9C to perform cleaning/maintenance of the pre-filter.

[0159] FIG. 9D illustrates the mode for the first backwash step, in which the first water filter 15A is backwashed by the filtered water from the second water filter 15B. The switch 7 is in water filtration orientation and the cam driver 8 is in orientation for the first backwash mode (BW1), which is a backwash mode for the first water filter 15A. The orientation of the cam driver 8 for this mode is indicated in the lower right corner of FIG. 9D. In this mode, V1, V2 and V5 are blocked by clamping, using the levers 19 of the multi flow arrangement 17 and cams 20A of the cam shaft 20. Water flows from the from the pre-filter 9 through the second inflow hose 23B and through the second water filter 15B for being filtered by the second water filter 15B. From the second water filter 15B, the filtered water flows out of the second water filter 15B thorough clean water outlet 27B and into the tubular cross bar 36 and further in reverse into the first clean water outlet 27A of the first water filter 15A and in backwash direction across the membrane (not shown) inside the first water filter 15A from the clean side to the dirt side. As V5 is closed, corresponding to the first inflow hose being clamped and closed, the water on the dirt side of the membrane in the first in water filter 15A can only leave through the flush outlet 33A at the top of the first water filter 15A and is then discarded through the first backwash hose 25A and the backwash release 34.

[0160] FIG. 9E illustrates the mode for the first forward flush step. The switch 7 is in water filtration orientation and the cam driver 8 is in orientation for the first forward flush (Direct flow 1) through the first water filter 15A. The orientation of the cam driver 8 for this mode is indicated in the lower right corner of FIG. 9E. In this mode, V1, V2 and V3 are closed by using the cams 20A of the cam shaft 20. The water flows from the pre-filter 9 through the first inflow hose 23A through the water inlet 26A into the first filter 15A but is prevented from traversing the membrane due to the closed valves V1, V2, and V3, which implies clamping of the clean water hose 24 so that no clean water is dispensed from the clean water hose 24. The only way out of the first water filter 15A is though the first flush outlet 33A, resulting is a forward flush, flushing out debris that has been removed from the dirt water side of the filter membrane (not shown) during the foregoing backwash step. The forward flush water from the first water filter 15A is discarded through the first backwash hose 25A and out of the device through the backwash release 34.

[0161] FIG. 9F illustrates the mode for the backwash step of the second water filter 15B. In this backwash mode, the second water filter 15B is backwashed by the filtered water from the first water filter 15A. The switch 7 is in water filtration orientation and the cam driver 8 is in orientation for the second backwash mode (BW2), which is a backwash mode for the second water filter 15B. The orientation of the cam driver 8 for this mode is indicated in the lower right corner of FIG. 9F. In this mode, V1, V3, and V4 are blocked by using the cams 20A of the cam shaft 20. Water flows from the from the pre-filter 9 through the first inflow hose 23A and into the first water filter 15A, where it is filtered, before it leaves the first water filter 15A into the tubular cross bar 36. As the water in the clean water hose 24 cannot be dispensed through the tap 6, due to closed V1, it is pressed in reverse through the second clean water outlet 27B of the second water filter 15B and in backwash direction across the membrane inside the second water filter 15B from the clean side to the dirt side. As V3 is closed, the water on the dirt side of the membrane in the second water filter 15B can only leave through the flush outlet 33B at the top of the second water filter 15B and is then discarded through the second backwash hose 25B and the backwash release 34.

[0162] FIG. 9G illustrates the mode for the forward flush step for the second water filter 15B. The switch 7 is in water filtration orientation and the cam driver 8 is in orientation for the second direct flow mode (Direct flow 2), which is a forward flush mode through the second water filter 15B. The orientation of the cam driver 8 for this mode is indicated in the lower right corner of FIG. 9G. In this mode, V1, V4 and V5 are closed by using the cams 20A of the cam shaft 20. The water flows from the pre-filter 9 through the second inflow tube 23B and through the second water outlet 26B of the second water filter 15B but is prevented from traversing the membrane due to the closed valve V1. The only way out for the water is though the second flush outlet 33B of the second water filter 15B, resulting is a forward flush, flushing out debris that has been removed from the dirt water side of the filter membrane (not shown) in the second water filter 15B. The forward flush water from the second water filter 15B is discarded through the second backwash tube 25B and the backwash release 34.

[0163] FIG. 10 illustrates and alternative embodiment, in this the combination of cam driver 8 and the clamping member in the form of a lever 19A has been substituted by an alternative multi flow arrangement 17′ in which pinch valves 39, also called squeeze valves in the technical field, presses on the flexible hoses extending though the compartments 17A in order for the closing of the hoses for flow through the hoses. Operating each of the pinch valves 39 electrically by sending electrical signals by cable to the electrical connectors 41, the corresponding pinch valve 39 closes or opens for flow through the hose that is extending through the related compartment 17A.

[0164] In order to operate the pinch valves 39, the front panel 2A, as illustrated in FIG. 1 would use a switch, for example a button, instead of the handle 8A. Alternatively, a rotatable handle could be provided, for example a similar handle 8A as for manually operating the cam driver 8. This would imply the advantage that a user would have to operate the device in largely the same way, namely by rotating the handle 8A, irrespective of the backwash sequence being done by a cam driver 8 or by pinch valves 39. In these cases, the illustrations in FIGS. 7 and 8 as well as the backwash principles illustrated in FIG. 9 apply equally well. Merely, the cam driver 8 and the multi flow arrangement 17 would be exchanged.

[0165] This implies that there would be no requirements for further instructions, once a user has learned the operation of the device 1 and the device is exchanged from a version with a cam driver to a version with electrical pinch valves, as the handle 8A and its operation remains the same.

[0166] For the sequential activation of the pinch valves 39 according to a predetermined sequence, a pinch valve controller is provided, which is electrically connected to the electrical connectors 41 of the pinch valves 39 and configured for activating the pinch valves 39 of the multi flow arrangement 17′ sequentially for closing the hoses 23A, 23B, 24, 25A, 25B in accordance with a predetermined sequence for shifting between the filtration mode and the backwash mode, and optionally with the addition of the forward flush mode after backwashing.

[0167] FIG. 11 illustrated a further alternative embodiment which relatively to the embodiment in FIG. 10 is different in that the dirt water hose 22 is operated by an electrical dirt water pinch valve 40. With respect to user operation for opening or closing for flow through the dirt water hose 22, the front panel 2A, as illustrated in FIG. 1, could be provided with a switch, for example a button.

[0168] The switch for the pinch valve activation could also be of the rotatable type of switch 7 as illustrated in FIG. 1. For the user, there would be no difference in operating the rotatable switch 7 for activating a squeeze valve as illustrated in FIG. 7 with a cam 28 and lever 29 for squeezing dirt water hose 22 in canal 23, or operating the rotatable switch 7 for activating an electrical pinch valve 40. This also implies that there would be no requirements for further instructions, once a user has learned the operation of the device 1 and the device is exchanged from a version with switch 7 with a squeeze valve 28, 29 to a version with an electrical dirt water pinch valve 40, as the rotatable switch 7 and its operation remains the same.

[0169] The dirt water pinch valve 40 is illustrated in combination with the multi flow arrangement 17′ with pinch valves 39 of the multi flow arrangement 17′. However it may alternative be combined with the multi flow arrangement 17 that is operated by the cam drive, as illustrated in FIG. 4B and 5. The above arguments for similar operation and applicability of FIGS. 7, 8, and 9 apply equally well in this case, irrespective of the closing by squeezing being done by cams 20A and levers 19 or by electrical pinch valves 39.

[0170] In further alternative embodiment, the backwash cycle is performed automatically with a timer or initiated after a certain volume of filtered water. This implies some logic, for example a small computer functionally connected to an automated backwash function.

[0171] In even further alternative embodiments, the switch 7 is coupled to a card reader, a contactless reader, or a SIM card where the activation of the dirt water pinch valve 40 is dependent on a predetermined amount of water to be dispensed. For example, the volume to be dispensed depends on credit that is available for purchasing clean water, for example with one of the cards mentioned above, optionally in dependence on a code sent by SMS. It is thus possible to use the device in an automated fashion for delivery of clean water in dependence of payment.

REFERENCE NUMBERS

[0172] 1 filtration device

[0173] 2 casing

[0174] 2A front panel of casing 2

[0175] 3 demountable lid

[0176] 4 slidable/lockable clamps

[0177] 5 pre-filter cartridge access cap

[0178] 6 tap

[0179] 6′ common dispenser tube

[0180] 7 switch

[0181] 8 cam driver

[0182] 8A handle

[0183] 9 pre-filter with housing

[0184] 9A pre-filter element (large size filtration)

[0185] 9B pre-filter element (medium size filtration)

[0186] 9C pre-filter element (small size filtration)

[0187] 9D pre-filter support 10 dirt water inlet

[0188] 11 backwash water outlet

[0189] 12 common water supply tube

[0190] 13 common release tube

[0191] 14 pressure regulator

[0192] 15A, 15B first and second water filter

[0193] 16 optional decontamination stage, for example activated-carbon filter

[0194] 17 multi flow arrangement

[0195] 17′ alternative multi flow arrangement with pinch valves 39

[0196] 17A Compartments in multi flow arrangement 17

[0197] 18A, 18B pair of aligned apertures

[0198] 19 clamping member in the form of a lever

[0199] 19A moving end of the lever 19

[0200] 20 cam shaft

[0201] 20A cam on cam shaft 20

[0202] 21 hose

[0203] 21A squeezed part of hose 21

[0204] 22 dirt water hose for transport of dirt water from the pressure regulator 14 to canal 23 around switch 7

[0205] 23A, 23B first and second water inflow hoses for flow of pre-filtered water from pre-filter 9 through multi flow arrangement 17 and to first and second water filters 15A, 15B

[0206] 24 clean water hose connected between tubular bar 36 and tap 6

[0207] 25A, 25B first and second backwash hose

[0208] 26A, 26B water inlets into water filters 15A, 15B

[0209] 27A, 27B clean water outlet of filters 15A, 15B

[0210] 28 first cam on switch 7

[0211] 29 lever at switch 7 for squeezing dirt water hose 22 in canal 23

[0212] 30 recess in cam driver for cooperating with second cam 29

[0213] 31 enlarged circle of FIG. 8

[0214] 32 one way ratchet mechanism

[0215] 33A, 33B flush outlets of water filter 15A, 15B

[0216] 34 fitting with backwash water outlet 11

[0217] 35 canal for the dirt water hose 22 around the switch 7

[0218] 36 tubular bar connected to clean water outlets 27A, 27B 36A hose connector

[0219] 37 bottom plug for pre-filter element 9A

[0220] 38 second cam on switch 7

[0221] 39 pinch valve in multi flow arrangement 17

[0222] 40 dirt water pinch valve for dirt water hose 22

[0223] 41 electrical connectors in pinch valves 39, 40