WO2012072452A2

WO2012072452A2 - Water filter apparatus

Info

Publication number: WO2012072452A2
Application number: PCT/EP2011/070717
Authority: WO
Inventors: Michael John Smith; Stevan Paul Tortorella
Original assignee: Ge Healthcare Uk Limited
Priority date: 2010-11-29
Filing date: 2011-11-22
Publication date: 2012-06-07
Also published as: GB201020184D0; WO2012072452A3

Abstract

Embodiments of the invention relate to shower apparatus for filtering bacteria, in particular Legionella bacteria, from water supplies. Conventional bacterial filtration devices comprise a single filtration module that is fixed permanently within the device. Such constructions have a relatively short lifespan and at the end of the service life are disposed of and replaced; this continual routine of replacement may be costly and labour intensive. According to an embodiment of the present invention, a shower apparatus is provided comprising a handle portion withan opening for receiving water; a head portion, comprising one or more openings through which the water may pass to the exterior of the head portion; and a set of filters for fitting in the shower apparatus. A first filter is located in the handle and a second filter is located in the head portion such that water passes through both the first and second filters. The separation of the first and second filters extends the life of the apparatus due to an increase in effective filtration area.

Description

Water Filter Apparatus

Field of the Invention

The present invention relates to a shower apparatus and method for removal of bacteria from water and in particular, but not exclusively, to removal of bacteria of the genus Legionella.

Background of the Invention

Manmade water sources, such as water tanks in private houses, hospitals, residential homes and so on often contain bacteria, such as Legionella, that are harmful to human health. Such bacteria may be transmitted via water distribution and delivery systems, such as showers, which form a mist of droplets containing the bacteria that may be inhaled. Hospital-acquired Legionella pneumonia, otherwise known as "Legionnaires disease", has a very high fatality rate and, therefore, measures to prevent the spread of the Legionella bacteria are particularly important in the water distribution systems of healthcare facilities.

Growth of Legionella bacteria can be controlled by chemical or thermal treatments in water tanks. Dispersive treatments such as copper-silver ionisation, and hyperchlorinisation with chlorine dioxide or monochloramine can destroy bio-films that harbour Legionella bacteria. In addition, non- dispersive treatments such as ultraviolet irradiation or pasteurisation can kill Legionella bacteria. However, these treatments must be repeated regularly in order to remain effective. For many sources of Legionella bacteria this is difficult, impractical or highly costly. Another problem with treating water at its source is that there is a danger of re-contamination of the water at points further along a water distribution system.

A proposed solution to this problem for water distribution in hospitals and other healthcare facilities is to filter the water at the point of use. Taps and showerheads can be fitted with a filter that transmits water molecules but prevents the passage of the relatively large Legionella bacteria. However, this solution can be costly and requires a high degree of maintenance, as filters of this type have a very limited lifetime and need regular replacement. For example, Aquasafe produce a disposable shower containing a filter located in the handle for removing Legionella bacteria. Laboratories Anios also manufacture disposable filtration devices which can be fitted directly to a shower hose. However, these devices have a relatively low effective surface area, particularly as a result of the relatively limited space typically available in such devices; as a result, the filters of these devices quickly become saturated, resulting in the lifetimes of the devices being short relative to the lifetime of a standard shower unit. Existing filtration devices thus require frequent replacement, which can involve considerable effort and expense.

It is an object of the present invention to at least mitigate some of the problems of the prior art. Summary of the Invention

In accordance with a first aspect of the present invention, there is provided a shower apparatus for filtering bacteria from water, the shower apparatus comprising:

a handle portion having an opening for receiving water from a water supply;

a shower head portion fluidly connected to the handle portion to receive water therefrom, the shower head portion comprising one or more openings through which water received from the handle portion can pass to the exterior of the shower head portion;

a first filter located in the handle portion, the first filter being located such that water received from the water supply at the handle portion passes through the first filter;

a second filter located in the shower head portion, the second filter being located such that water received from the handle portion at the shower head portion, having passed through the first filter, passes through the second filter. By providing a filter in each of the shower handle portion and the shower head portion, the total effective filter surface area is increased, thus increasing the life of the shower apparatus, and reducing the frequency at which the filters need to be replaced. Furthermore, the two different filters may be used for different purposes.

In some embodiments, the first filter is coarser than the second filter. In some cases, each of the first filter and the second filter comprises a porous membrane, the porous membrane of the first filter having a pore size greater than the pore size of the porous membrane of the second filter. The second filter may be configured for removing bacteria, such as Legionella from the water. Thus, the first filter may act as a pre-filter, removing larger contaminants from the water, with the second filter being a bacterial filter.

Preferably, the second filter is removable from the shower head. Preferably, the shower head portion comprises a face portion and the one or more openings are located in the face portion, and a body portion which is arranged to be connected to the handle portion, the face portion being connected to the body portion, wherein the face portion is detachable from the body portion to enable removal of the second filter from the shower head portion. These features enable the second filter to be removed from the shower head portion and replaced. The second filter can thus be replaced, without a need to replace the entire apparatus.

Preferably, the first filter is removable from the handle portion. The handle portion may comprise a handle end portion and a handle body portion, the handle end portion being removable from the handle body portion to enable removal of the first filter from the handle portion. The first filter can thus be replaced, without a need to replace the entire apparatus.

In some embodiments, the shower head portion is detachable from the handle portion. This enables the first and/or second filter to be replaced without removing the filter from the shower handle portion or shower head portion, respectively. In some embodiments, at least one of the shower head portion and the shower handle portion is comprised of, or treated with, an antimicrobial material. This provides further protection against bacteria in the water.

One or both of the first filter and the second filter may comprise a repeatedly folded filter membrane. This provides a large filtration surface area.

The repeatedly folded filter membrane may be located in a filter holding device. Locating the filter membrane in a filter holding device can provide the filter with rigidity, which can aid insertion of the filter into the shower apparatus.

In accordance with a second aspect of the present invention, there is provided a set of filter assemblies for a shower apparatus, which enables the apparatus to be configured to remove bacteria from water, the set of filters comprising:

a first filter assembly for fitting in a handle portion of the shower apparatus, the first filter assembly being arranged such that, when fitted in said handle portion, water received from the water supply at the shower handle portion passes through said first filter assembly; and

a second filter assembly for fitting in a head portion of the shower apparatus, the second filter assembly being arranged such that, when fitted in said handle portion, water received from the head portion at the head portion passes through the second filter.

Such a set of filter assemblies may be used to configure shower apparatus for filtering bacteria, by fitting the filters into the apparatus, or to replace the filters described above in relation to the first aspect of the present invention.

The first filter assembly may comprise a cylindrical container and a repeatedly folded filter membrane located in the cylindrical container. The first filter assembly may be sealed at at least one end and comprise an opening in a said sealed end, the opening being arranged to form a seal with a connector associated with the shower handle portion, so that water can be received in the interior of the first filter assembly via said opening and so as to prevent water passing around a periphery of the first filter assembly.

The second filter assembly may comprise a filter holding device and a repeatedly folded filter membrane located on the holding device. The repeatedly folded filter membrane may comprise a cover over at least a portion of a surface adjacent to said holding device, the cover being arranged to form a seal with said filter holding device. The holding device may be configured to form a seal with said shower head portion, so as to prevent water passing around a periphery of the holding device. These features ensure effective filtering of water passing through a shower apparatus configured with the set of filters.

In accordance with a third aspect of the present invention, there is provided a method for filtering bacteria from water, comprising:

receiving water at a handle portion of a shower apparatus;

filtering the water received at the handle portion of the shower apparatus using a first filter, the first filter being located in the handle portion;

receiving water from the handle portion at a shower head portion of the shower apparatus, the water received at the shower head portion having been filtered by said first filter; and

filtering the water received at the shower head portion using a second filter, the second filter being located in the shower head portion.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, given by way of example only, which is made with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 shows an exploded view of a shower apparatus in accordance with a first embodiment of the present invention;

Figures 2a to 2c show perspective views of filters for use in embodiments of the present invention; Figure 3 shows a cross-sectional view of a shower apparatus according to a second embodiment of the present invention.;

Figure 4 shows an exploded view of a shower apparatus according to a third embodiment of the present invention;

Figure 5 shows a cross-sectional view of a shower apparatus indicating water flow paths when the shower apparatus is in use, in accordance with embodiments of the present invention.

Detailed Description of the Invention

Figure 1 is an exploded view of a shower apparatus 10 according to one embodiment of the invention, comprising a shower handle portion 11 and a shower head portion 12. The shower handle portion 11 includes an end portion which may comprise a connector 11a for connecting the shower handle portion 11 to a water supply; the connector 11a may be suitable for connecting to a shower hose (not shown), for example. The shower handle portion 11 also includes a handle l ib, which is hollow and has an opening 13 at an end, to which the connector 11a is adapted to be connected; the opening 13 enables water to flow into the shower handle portion 11 from the water supply.

The shower head portion 12 includes a shower head body portion 12a and a shower head face portion 12b; the shower head body portion 12a is connected to the shower handle portion 11 and, during use, water flows from the shower handle portion l ib into the shower head body portion 12a, which is hollow and roughly cylindrical in shape. The shower head face portion 12b, which can be referred to as a "sprinkler plate", includes a pattern of holes 14 through which water can flow to the exterior of the apparatus 10. Any pattern of holes 14 may be used in the shower head face portion 12b, as desired; in some cases, a single hole may be used instead of a pattern of multiple holes.

A filter holding device in the form of a holding cage 15, which may be constructed from plastic, or any other suitable material, and which has an external size and shape that enable it to be fitted into the shower handle l ib is located in the shower handle 1 lb. The holding cage 15 holds a first filter, which is referred to herein as a "handle filter" 16a; these parts are described in detail below.

A filter holding device in the form of a holder 17 is located within the shower head body portion 12a. The filter holder 17 may be constructed from plastic, or any other suitable material and corresponds in shape and size to the internal dimensions of the shower head body portion 12a. The filter holder 17 holds a second filter, which is referred to herein as a "head filter" 16b (these parts are described in more detail below).

In the embodiment shown in Figure 1, the connector 11a includes a threaded portion 18b, which interlocks with a corresponding threaded portion 18a in the handle 1 lb, allowing the handle filter 16a to be removed and replaced as required, by unscrewing the connector 11a from the handle l ib; thus the connector 11a may function both as a means for connecting the handle l ib to the water supply, as described above, and as a detachable means for providing access to the handle filter 16a to permit it to be removed from the handle 1 lb.

Further, the shower head face portion 12b includes a threaded portion 19b, that interlocks with a corresponding threaded portion 19a in the shower head body portion 12a, allowing the shower head face portion 12b to be unscrewed and removed from the shower head body portion 12a, which in turn allows the head filter 16b to be removed and replaced.

The handle filter 16a and the head filter 16b together act to filter water passing through the shower apparatus 10, and in particular, at least one of the filters 16a, 16b is arranged to remove bacteria, such as Legionella bacteria, from water passing through the shower apparatus 10. Each of the filters 16a, 16b is typically a surface filter, and may comprise a porous membrane, having a pore size selected so as to filter out bacteria but allow water molecules to pass through. The porous membrane may be repeatedly folded in order to provide an increased filtration surface area. In some embodiments, the handle filter 16a acts as a pre-filter and has a larger pore size than that of the head filter 16b, the handle filter 16a acting to remove larger contaminants from the water, such as limescale, and the head filter 16b acting to remove bacteria. Legionella bacteria have dimensions of the order 0.5 to 0.7 μπι, so in order to be effective against transmission of Legionella, the head filter 16b should comprise a membrane having a pore size of 0.5 μπι or smaller. Typically, the head filter 16b comprises a membrane having a pore size of approximately 0.2 μπι and the handle filter 16a, when acting as a pre-filter, has a pore size of approximately 1 μπι. The membranes may be constructed from polyethersulfone (PES), nylon, or polypropylene, for example, or from any other suitable material.

Figures 2a to 2c show an example of a filter construction which may be used in embodiments of the present invention. Figure 2a shows a filter 16, which for the filters 16a, 16b can be referred to as a "pleat pack" filter 16 . The "pleat pack" filter 16 is constructed from a flat sheet of filtering membrane 20. The membrane 20 is firstly folded to provide a plurality of pleats 21 and then the two ends 22 of the pleated membrane 20 are rolled towards one another and fixed together using, for example, an ultrasonic weld to form a continuous pleated loop as illustrated in Figure 2b. The continuous pleated loop has a substantially cylindrical configuration and has a hollow chamber 23 in its central portion by virtue of the joining of the two ends 22 of the pleated membrane. The ends of the cylinder formed by the folded and rolled pleated membrane 20 are covered with covers or sealing caps 24 as illustrated in Figure 2c. One or both of the sealing caps 24 may be provided with an opening 25 to coincide with the chamber 23; the function of the opening 25 will be described in more detail below.

It will be appreciated that by repeatedly folding, and thereby pleating the filter membrane 20, it is possible to provide a very large surface area for the handle filter 16a and the head filter 16b in embodiments of the present invention. Typically, the handle filter 16a has a total membrane surface area of approximately 1000 cm² and the head filter 16b has a total membrane surface area of approximately 400 cm².

Increasing the filter membrane surface area increases the lifetime of the filter, since contaminant residues can be collected over a larger area. Therefore, the filter membrane 20 takes longer to acquire a given amount of contamination per unit area of the membrane, and, as a result takes longer to "clog up" and become unusable. The effective filter surface area represents an additional increase over prior art filters in the provision of two filters, namely the handle filter 16a and the head filter 16b. In some embodiments, a further filter membrane may be wrapped around the circumference of the pleat pack filter 16, to still further increase the effective filter area.

In the embodiment shown in Figure 1, the handle filter 16a and head filter 16b are independently replaceable, as described above. This means that replacement filters may be provided, for example as a set including a handle filter 16a and a head filter 16b, and used to replace the filters in the shower apparatus 10 when required. This avoids replacing the entire shower apparatus 10 when a filter reaches the end of its useful life, saving costs. Further, since the filters 16a, 16b may have different lifetimes, for example in the case where the head filter 16a is a pre-filter, as described above, one filter may be replaced without replacing the other, avoiding unnecessary replacement of a filter prior to the end of its useable lifetime.

Locating the handle filter 16a and head filter 16b in the holding cage 15 and filter holder 17 respectively provides rigidity to the resulting filter assemblies (the term "filter assembly" as used herein, should be understood to refer to a filter 16a, 16b either alone or in combination with other parts, such as a holding cage 15 or filter holder 17). This facilitates insertion of the filters 16a, 16b into the shower apparatus 10. Replacement of the handle filter 16a or the head filter 16b may be performed by replacing the filter 16a, 16b together with its holding device 15, 17, or the holding device 15, 17 may be re-used, with only the filter 16a, 16b being replaced.

In addition, by appropriately dimensioning the first and second filters 16a, 16b, it may be possible to retro-fit a set of such filters 16a, 16b to existing shower apparatus to configure it to function in accordance with at least one embodiment of the present invention. However, in some embodiments of the invention, one or more of the handle filter 16a and the head filter 16b may be permanently fixed in their respective housings.

Figure 3 shows a cross-section of a shower apparatus 10, in accordance with a second embodiment of the invention, in which the handle filter 16a and the head filter 16b are permanently fixed in the shower handle l ib and the shower head body portion 12a respectively; this may be implemented by, for example, ultrasonically welding a connector 11c to the handle l ib and the shower head face portion 12b to the shower head body portion 12a. The shower handle portion 11 and the shower head body portion 12 are integral with one another. The connector 11c connects the handle l ib to a water supply, in a similar manner to 11a described above. In this embodiment, the handle filter 16a includes openings 25a, 25b at each end, which allows the handle filter to be located on a protrusion 26 of the holding cage 15 at one end 25b, and on a conduit 27 leading from the connector 11c at the other end 25a. The holding cage 15 also includes a number of openings 28 along its side walls, the function of which will be described in detail below in relation to Figure 5.

The head filter 16b includes an opening 25c at one end only, allowing it to fit around a central protrusion 29 in the filter holder 17. The central protrusion 29 includes a number of openings 30 in its side walls, the function of which will be described in detail below in relation to Figure 5.

In the embodiment of Figure 3, rather than replacing the individual filters 16a, 16b, the shower apparatus 10 as a whole can be replaced by disconnecting the connector 11c from the water supply. This embodiment has the same advantages of increased filter surface area discussed above, and thus increased filter lifetime; further, since the filters 16a, 16b are permanently sealed in the shower apparatus 10, the risk of filters being inadvertently removed without replacement is reduced.

Figure 4 shows an exploded view of a further embodiment of shower apparatus 10 in accordance with the present invention in which the shower handle l ib includes a threaded portion 31a which interlocks with a corresponding threaded portion 31b in the shower head body portion 12a. In this embodiment, the shower handle portion 11 includes a connector l id which in addition to connecting the handle 1 lb to a water supply, includes a cylinder portion 32 with a conduit 33 extending along a longitudinal axis of the cylinder portion 32 for receiving the filter 16a. The handle filter 16a may fit into the cylinder portion 32, with an opening (not shown) in one end fitting around the conduit tube 33. Since the handle filter 16a thus fits directly into the connector 1 Id in this embodiment, a filter holding device may be omitted.

The connector l id may be removably attached to the handle l ib, for example using a "snap fit" arrangement, or it may be permanently attached to the handle 1 lb using an ultrasonic weld, as described above in relation to Figure 3.

In Figure 4, the shower head face portion 12b and the shower head body portion 12a are each provided with respective threaded portions 19b, 19a to permit the shower head face portion 12b to be removed from the shower head body portion 12a. However, in some embodiments, the shower head face portion 12b may be permanently fixed to the shower head body portion 12a.

In the embodiment of Figure 4, since the shower head body portion 12a is detachable from the shower handle 1 lb, rather than removing and replacing individual filters 16a, 16b as per the embodiment of Figure 1, or replacing the entire shower apparatus 10, as per the embodiment of Figure 3, it is possible to unscrew the shower head portion 12 from the shower handle portion 11, and replace the shower head portion 11 or the shower handle portion 12 as a whole, without removing the filters 16a, 16b contained in these portions.

Operation of the shower apparatus 10 will now be described with reference to Figure 5. Although Figure 5 corresponds to the embodiment described above with reference to Figure 3, it will be understood that the same, or similar, operation of the shower apparatus will apply to other embodiments of the present invention.

The direction of the arrows in Figure 5 shows the direction of flow of water when the shower apparatus 10 is in use. Water enters the shower apparatus from a supply along the conduit 27 of the connector 11c, and flows into the handle filter 16a via an opening 25a at one end of the handle filter 16a. The sealing cap 24a located adjacent to the connector 11c forms a seal with the conduit 27 in order to prevent water escaping around the periphery of the handle filter 16a.

The protrusion 26 in the holding cage 15 is in sealing contact with the sealing cap 24b at an opposite end of the handle filter 16a. Accordingly, once water enters the handle filter 16a, it is forced through the filter membrane 20a, and exits the holding cage 15 through the openings 28 located in the side walls of the holding cage 15. The water then flows along the periphery of the holding cage 15 towards the shower head portion 12.

In embodiments in which no filter holding device 15 is used, such as that described above in relation to Figure 3, the opening 25b in the handle filter 16a located at its end furthest from the connector 1 lc is not required. In this case the sealing cap 24b would extend over the whole surface area of that end of the handle filter 16a, ensuring that no unfiltered water escapes via that end. Water exits the handle filter 16a by passing through the filter membrane 20a and flowing along the periphery of the handle filter 16a.

Once the water has exited the handle filter 16a, it flows to the shower head portion 12 of the shower apparatus 10. The head filter 16b is located in filter holder 17, and has a seal cap 24c located at an end of the head filter 16b adjacent the filter holder 17. The seal cap 24c is in sealing contact with the filter holder 17, which, in turn, is in sealing contact with the shower head face portion 12b. Further, an opposite end of the head filter 16b is sealed by a seal cap 24d. Accordingly, water is forced through the side walls of the head filter 16b, passing through the filter membrane to the interior of the head filter 16b. The filtered water then passes through openings 30 in the side of the central protrusion 29, along the interior of the central protrusion and through the shower head face portion 12b to the exterior of the shower apparatus 10. Although not shown in the diagrams, O-rings, gaskets and/or other suitable means for sealing may be used to ensure water-tight connections where required.

Some or all of the components described above which house the head filter 16b and the handle filter 16a, such as the shower handle l ib, shower head body portion 12a and shower head face portion 12b may be comprised of a moulded plastic, or any other suitable material. Further, one or more of these components may be comprised of an anti-microbial material or treated with an anti-microbial substance; this may be implemented by adding a suitable silver compound to the plastic, for example.

The above embodiments are to be understood as illustrative examples of the invention. Further embodiments of the invention are envisaged. For example, although in some embodiments described above, the shower head face portion 12b was fixed to the shower head body 12a using threaded portions 19b, 19a located on the shower head face 12b and shower head body 12a respectively, in other cases a snap-fit or other type of detachable connection may be used.

In the embodiment described above in relation to Figure 3, it was described that ultrasonic welding could be used to permanently fix different components together. Alternatively, an adhesive could be used for this purpose.

Further, although the cross-section of the shower handle portion 11 described above is circular, differently shaped cross sections, such as square or elliptical cross sections may be used. Using an elliptical cross-section has the advantage that it improves the ease of fitting of the handle filter 16a; this is due to the tendency of handle filter 16a to deform when gripped to itself form an elliptical cross section.

It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

1. A shower apparatus for filtering bacteria from water, the shower apparatus comprising:

a handle portion having an opening for receiving water from a water supply;

a first filter located in the handle portion, the first filter being arranged such that water received from the water supply at the handle portion passes through the first filter;

a second filter located in the shower head portion, the second filter being arranged such that water received from the handle portion at the shower head portion, having passed through the first filter, passes through the second filter.

2. A shower apparatus according to claim 1, wherein the first filter is coarser than the second filter.

3. A shower apparatus according to claim 2, wherein each of the first filter and the second filter comprises a porous membrane, the porous membrane of the first filter having a pore size greater than the pore size of the porous membrane of the second filter.

4. A shower apparatus according to any preceding claim, wherein the second filter is configured for removing bacteria, such as legionella from the water.

5. A shower apparatus according to any preceding claim, wherein the second filter is removable from the shower head portion.

6. A shower apparatus according to claim 5, wherein the shower head portion comprises:

a face portion and said one or more openings of the shower head portion are located in the face portion; and

a body portion which is arranged to be connected to the handle portion, the face portion being connected to the body portion,

wherein the face portion is detachable from the body portion to enable removal of the second filter from the shower head portion.

7. A shower apparatus according to any preceding claim, wherein the first filter is removable from the handle portion.

8. A shower apparatus according to any preceding claim, wherein the handle portion comprises a handle end portion and a handle body portion, the handle end portion being removable from the handle body portion to enable removal of the first filter from the handle portion.

9. A shower apparatus according to any preceding claim, wherein the shower head portion is detachable from the handle portion.

10. A shower apparatus according to any preceding claim, wherein at least one of the shower head portion and the shower handle portion is comprised of, or treated with, an antimicrobial material.

11. A shower apparatus according to any preceding claim, wherein the at least one of the first filter and the second filter comprises a repeatedly folded filter membrane.

12. A shower apparatus according to claim 11, comprising a filter holding device, wherein the repeatedly folded filter membrane is located in the holding device.

13 A shower apparatus according to any preceding claim, wherein the handle portion has an elliptical or circular cross-section.

14. A shower apparatus according to any preceding claim, wherein the shower handle portion comprises a connector for connecting the shower handle portion to a shower hose.

15. A set of filter assemblies for a shower apparatus, which enables the shower apparatus to be configured to remove bacteria from water, the set of filter assemblies comprising:

a first filter assembly for fitting in a handle portion of the shower apparatus, the first filter assembly being arranged such that, when fitted in said handle portion, water received from a water supply at the shower handle portion passes through said first filter assembly; and

a second filter assembly for fitting in a head portion of the shower apparatus, the second filter assembly being arranged such that, when fitted in said shower head, water received from the shower handle portion at the head portion passes through the second filter assembly.

16. A set of filter assemblies according to claim 15, wherein the first filter assembly comprises a cylindrical filter holding device and a repeatedly folded filter membrane located in the cylindrical filter holding device.

17. A set of filter assemblies according to claim 15, comprising a further filter membrane, the further filter membrane being located around a circumference of the repeatedly folded filter membrane.

18. A set of filter assemblies according to any of claim 15 to claim 17, wherein the first filter assembly comprises a repeatedly folded filter membrane, the first filter assembly being sealed at at least one end and comprising an opening in said sealed end, the opening being arranged to form a seal with a connector associated with the shower handle portion, so that water can be received in the interior of the first filter assembly via said opening and so as to prevent water passing around a periphery of the first filter assembly.

19. A set of filter assemblies according to any of claim 15 to claim 18, wherein the second filter assembly comprises a filter assembly holding device and a repeatedly folded filter membrane located on the holding device.

20. A set of filter assemblies according to claim 19, comprising a further filter membrane, the further filter membrane being located around a circumference of the repeatedly folded filter membrane.

21 A set of filter assemblies according to either of claim 19 and claim 20, wherein the second filter assembly comprises a cover over at least a portion of a surface adjacent to said holding device, the cover being arranged to form a seal with said filter holding device.

22. A set of filter assemblies according to any of claim 19 to claim 21, wherein the holding device is configured to form a seal with said shower head portion, so as to prevent water passing around a periphery of the holding device.

23. A method for filtering bacteria from water, comprising:

receiving water at a handle portion of a shower apparatus;

filtering the water received at the handle portion of the shower apparatus using a first filter, the first filter being located in the handle portion; receiving water from the handle portion at a shower head portion of the shower apparatus, the water received at the shower head portion having been filtered by said first filter; and