A drain system and a shower or shower cabin

Abstract

A drain system for recovering thermal energy from a flow of shower or faucet greywater comprises a first drain system inlet for receiving greywater; a drain system outlet for discharging greywater to a drain; and a heat exchanger comprising a grey water inlet arranged downstream of the drain system inlet, and a grey water outlet arranged upstream of the drain system outlet, the heat exchanger being configured to heat a flow of incoming cold water with the greywater flowing from the grey water inlet to the grey water outlet. The drain system further comprises a second drain system inlet for receiving greywater; a by-pass conduit arranged downstream of the second drain system inlet and upstream of the drain, the by-pass conduit being configured to provide a greywater by-pass of the heat exchanger; and an indicator configured to indicate a flow of greywater bypassing the heat exchanger in the by-pass conduit.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to drain systems for recovering thermal energy from a flow of greywater. The present invention also relates to showers or shower cabins comprising such drain systems.BACKGROUND OF THE INVENTION

[0002] A shower typically comprises a shower head fluidly connected to a shower mixer configured to mix hot water from a hot water supply and cold water from a cold-water supply. The hot water supply may e.g. be water heated by a domestic boiler (using a combustible fuel, electricity, district heating, or a heat pump). Thus, showers are energy-intensive units, consuming a lot of energy to heat the hot water used for showering.

[0003] Devices that recover heat from the shower greywater (i.e. the wastewater discharged from a shower floor into a shower drain system) are known from the prior art, e.g. from GB2232749, U.S. Pat. No. 4,619,311, GB2052698 and DE29615555. Such devices are typically installed in the shower drain system to recover heat from the shower greywater, for example from a shower tray, using a heat exchanger. Such drain systems may be referred to as heat-recovering drain systems.

[0004] The greywater flow capacity of the heat recovery drain system can be impaired due to various problems in the drain system, e.g. clogging of the drain system due to accumulation of debris, such as textile fibers and hair, as well as grease and shower products. In some situations, the amount of greywater in the heat-recovering drain system exceeds the capacity of the heat exchanger, e.g. causing flooding.

[0005] Thus, there is a need in the industry for an improved drain system.SUMMARY

[0006] An object of the present invention is to overcome the above problems, and to provide a drain system for recovering thermal energy from a flow of shower or faucet greywater which is improved compared to prior art solutions. The drain system comprises a heat exchanger configured to recover thermal energy from the greywater and a by-pass conduit for receiving a flow of greywater when the amount of greywater exceeds the capacity of the heat exchanger and / or the capacity of the heat recovery system comprising the heat exchanger (and e.g. any conduit or filter arranged upstream of the heat exchanger). The drain system further comprises an indicator for indicating to a user that greywater is flowing through, or is expected to flow through, the by-pass conduit. Thereby, the user is given an indication that the flow of greywater through the heat exchanger, or through the heat recovery system comprising the heat exchanger, has reached, or has exceeded, its capacity. A flow of greywater through the by-pass conduit can be a consequence of problems in the drain system preventing, or at least reducing, the flow of greywater through the heat exchanger or through a filter of the heat recovery system, e.g. clogging due to accumulation of debris, such as textile fibers, hair, grease and / or shower products. The indicator may thus inform the user of such clogging, and allow the user to take measures to improve the function of the drain system.

[0007] According to at least a first aspect of the present invention, a drain system for recovering thermal energy from a flow of shower or faucet greywater is provided. The drain system comprises:

[0008] a first drain system inlet for receiving greywater,

[0009] a drain system outlet for discharging greywater to a drain,

[0010] a heat exchanger comprising a grey water inlet arranged downstream of the drain system inlet, and a grey water outlet arranged upstream of the drain system outlet, the heat exchanger being configured to heat a flow of incoming cold water with the greywater flowing from the grey water inlet to the grey water outlet,

[0011] a second drain system inlet for receiving greywater,

[0012] a by-pass conduit arranged downstream of the second drain system inlet and upstream of the drain, the by-pass conduit being configured to provide a greywater by-pass of the heat exchanger, and

[0013] an indicator configured to indicate a flow of greywater bypassing the heat exchanger in the by-pass conduit.

[0014] Hereby, an improved drain system for recovering thermal energy from a flow of greywater is provided. As the drain system includes a by-pass conduit to prevent flooding, and an indicator to indicate the flow of greywater through the by-pass conduit bypassing the heat exchanger, an impaired heat recovery performance of the drain system can be detected.

[0015] During use of the drain system, greywater flows to the heat exchanger, to pre-heat incoming cold water, e.g. provided to the shower arrangement.

[0016] Thereby, the heat of the greywater can be recovered to lower energy consumption. However, in some situations the heat exchanger is not capable of handling the full flow of greywater in the drain system. As the flow of greywater through the heat exchanger is reduced, the greywater level within the drain system typically rises, and greywater is (in addition to being received by the first drain system inlet), directed to the second drain system inlet and the by-pass conduit. Thus, the second drain system inlet and the by-pass conduit are arranged to be passively activated when the greywater level within the drain system rises above a predetermined threshold. Hence, there is no need to actively open (e.g. by using a controllable valve or the like) the second drain system inlet and / or the by-pass conduit in response to that the greywater level within the drain system rises above the predetermined threshold. The greywater being received by the by-pass conduit is directed to the drain, e.g. via the drain system outlet, without passing through the heat exchanger, and the thermal energy of this portion of the greywater is thus not heat exchanged, at least not with said heat exchanger of the drain system. As greywater flows through the by-pass conduit, the indicator is activated. The user thus receives an indication that the flow of greywater through the heat exchanger has reached, or has exceeded, its present capacity. This allows the user to be properly notified. The user may upon such notification investigate the drain system and possibly take measures to improve the function of the drain system.

[0017] According to at least one example embodiment, the heat exchanger is a plate heat exchanger.

[0018] A plate heat exchanger typically provides an efficient heat transfer between the greywater and the incoming cold water. For example, the grey water outlet of the plate heat exchanger is arranged in an upper half of the heat exchanger.

[0019] According to at least one example embodiment, the drain system comprises a first side wall, the first side wall delimiting an enclosure housing the second drain system inlet, wherein the indicator is configured to be arranged within the enclosure.

[0020] Hereby, greywater is only allowed to flow into the by-pass conduit when the level of greywater in the drain system exceeds the height of the first side wall. Thus, greywater is prevented from flowing into the second drain system inlet and the by-pass conduit as long as the level of greywater in the drain system is lower than the height of the first side wall. Thus, the indicator will indicate a flow of greywater bypassing the heat exchanger only as the greywater level exceeds the height of the first side wall, and the greywater flows over the first side wall and into the enclosure, activating the indicator.

[0021] That is, as the indicator is arranged within the enclosure, it is activated first when the greywater level exceeds the height of the first side wall. Thus, the previously mentioned predetermined threshold may correspond to the height of the first side wall. Thereafter, the greywater is discharged to the by-pass conduit. The first side wall typically extends from a base portion of the drain system, the base portion comprising a planar horizontal surface wherein the first side wall extends vertically from the planar horizontal surface. The planar horizontal surface may be a greywater collecting surface configured to receive greywater from the shower or faucet, wherein the first drain system inlet and second drain system inlet are formed as openings in the planar horizontal surface. The height of the first side wall is referring to the extension of the first side wall in such vertical direction.

[0022] According to at least one example embodiment, the first side wall forms a circumferential wall housing the enclosure. According to at least one example embodiment, the enclosure defines an open greywater receiving area outwardly delimited by the first side wall.

[0023] According to at least one example embodiment, the indicator is configured to be activated before the greywater reaches the by-pass conduit, thereby providing an early indication to the user that greywater is expected to by-pass the heat exchanger. For example, the enclosure housing the indicator is arranged in between the second drain system inlet and the by-pass conduit, or alternatively, upstream of the second drain system inlet.

[0024] Thus, the second drain system inlet may define an upstream end of the enclosure, or define a downstream end of the enclosure. Thus, the previously mentioned open greywater receiving area may form the second drain system inlet, or an outlet in the downstream end of the enclosure forms the second drain system inlet.

[0025] According to at least one example embodiment, the drain system comprises a second side wall extending into the enclosure to partition the enclosure into a first sub-enclosure and a second sub-enclosure, wherein the indicator is arranged in the first sub-enclosure and the second drain system inlet is arranged in the second sub-enclosure.

[0026] Hereby, the control of the indicator can be improved. For example, the indicator may be activated by the presence of greywater, or a flow of greywater, in the first sub-enclosure, prior to the greywater reaching the second sub-enclosure and the second drain system inlet. Moreover, by housing the indicator in a separate sub-enclosure as compared to the second drain system inlet, any disturbances from the flow of greywater into the second drain system influencing the indicator may be reduced.

[0027] With reference to the previously mentioned embodiment comprising a base portion comprising a planar horizontal surface, the second side wall typically extends vertically from such planar horizontal surface correspondingly to the first side wall. Thus, the height of the second side wall extends in the same direction as the height of the first side wall. According to at least one example embodiment, the second side wall extends into the enclosure from the first side wall. That is, the second side wall may extend horizontally from the first side wall into the enclosure. Thus, the first sub-enclosure may be delimited by the first side wall and the second side wall, and the second sub-enclosure may be delimited by the first side wall and the second side wall. For example, the second side wall extends from a first portion of the first side wall to a second portion of the first side wall, the second portion being distant to the first portion. According to at least one alternative example embodiment, the second side wall is encompassed by the first side wall. Thus, the first sub-enclosure may be delimited fully (or only) by the second side wall.

[0028] According to at least one example embodiment, the first sub-enclosure and the second sub-enclosure are arranged to be in fluid connection with each other. Hereby, greywater may flow from the first sub-enclosure to the second sub-enclosure.

[0029] According to at least one example embodiment the second side wall comprises a slot, the slot being arranged to allow for greywater to flow from the first sub-enclosure to the second drain system inlet in the second sub-enclosure.

[0030] Hereby, greywater flow out of the first sub-enclosure into the second sub-enclosure in a controlled manner. Thus, in case the flow of greywater into the enclosure, e.g. the first sub-enclosure, decreases (e.g. in response to that the flow of greywater through the heat exchanger is increased, or a reduced total flow of greywater into the drain system), the indicator may indicate the lack of presence of greywater, or lack of flow of greywater, in the first sub-enclosure. Hereby, an efficient reset of the indicator is provided.

[0031] According to at least one example embodiment, the slot is sized to allow a predetermined flow of greywater from the first sub-enclosure to the second sub-enclosure. By sizing the slot to allow a predetermined flow of greywater from the first sub-enclosure to the second sub-enclosure, greywater may be accumulated in the first-sub enclosure depending on the inflow of greywater into the enclosure, or first sub-enclosure. For example, the indicator may be arranged in the first sub-enclosure to indicate the presence of greywater at a predetermined level of accumulated greywater in the first sub-enclosure. For example, the indicator may be arranged at a predetermined height in the first sub-enclosure.

[0032] According to at least one example embodiment, the slot is configured to evacuate greywater in the first sub-enclosure into the second sub-enclosure.

[0033] According to at least one example embodiment the slot is configured to extend along the entire height of the second side wall.

[0034] According to at least one example embodiment, the slot is configured as a recess at an upper portion of the second side wall, allowing the greywater to flow out of the first sub-enclosure as it reaches a predetermined level.

[0035] According to at least one example embodiment, the slot is arranged to be blocked by the indicator until a predetermined amount of greywater has been accumulated in the first sub-enclosure.

[0036] According to at least one example embodiment, the first side wall, the second side wall and / or the indicator comprises a guiding structure configured to guide the indicator in relation to the first side wall and / or the second side wall.

[0037] Hereby, the indicator can be guided to different positions depending on the amount of greywater in the first sub-enclosure, e.g. indicating corresponding flow of greywater in the by-pass conduit, to achieve a more precise indication of the greywater flow.

[0038] According to at least one example embodiment, the guiding structure comprises ribs arranged on the first side wall and / or the second side wall, the ribs being configured to guide the indicator in a vertical direction.

[0039] According to at least one example embodiment, the ribs are arranged helically on the first and / or the second side wall in the enclosure, such that the indicator is configured to be guided in a rotating manner. The rotation of the indicator can be used to indicate the amount of greywater in the first sub-enclosure, e.g. indicating corresponding flow of greywater in the by-pass conduit by displaying different fields to the user depending on the rotation angle of the indicator (e.g. differently colored fields).

[0040] According to at least one example embodiment, the height of the first and second side walls are sized such that, in use, greywater first flow into the first sub-enclosure before reaching the second sub-enclosure and the second drain system inlet.

[0041] Hereby, the flow of greywater through the enclosure can be controlled in a predetermined manner. By the configuration providing that greywater first flow into the first sub-enclosure and then into the second sub-enclosure, e.g. by the previously described slot, greywater is prevented from reaching the by-pass conduit without reaching the first sub-enclosure, and typically the indicator.

[0042] According to at least one example embodiment, the height of the first side wall varies around its circumference. With reference to the previously mentioned embodiment in which the first sub-enclosure is delimited by the first side wall and the second side wall, and according to at least one example embodiment, the portion of the first side wall having the lowest height is arranged to delimit the first sub-enclosure, and the portion of the first side wall having the highest height is arranged to delimit the second sub-enclosure.

[0043] Thus, as the greywater level within the drain system rises, greywater is allowed to flow into the first sub-enclosure and reach the indicator, before it is allowed to flow into the second sub-enclosure.

[0044] According to at least one example embodiment, the indicator comprises a floater.

[0045] Hereby, the buoyancy of the greywater can be utilized to activate the indicator, whereby an indicator with low complexity can be achieved. For example, and with reference to the previously described first sub-enclosure, the floater is sized and dimensioned to be arranged within the first sub-enclosure. For example, the floater is arranged to move at least in the vertical direction, e.g. by the guiding structure, in the first sub-enclosure as the greywater level increases in the first sub-enclosure (i.e. as water accumulates in the first sub-enclosure).

[0046] According to at least one example embodiment, the floater comprises a first part and a second part, wherein the second part is movably adjustable in relation to the first part. Hereby, the floater can be adapted with regards to the variations in the installation space, e.g. with regards to the height of the first sub-enclosure. It should be noted that another mechanical indicator than a floater may comprise such first and second parts. Thus, and according to at least one example embodiment, the mechanical indicator comprises a first part and a second part, wherein the second part is movably adjustable in relation to the first part.

[0047] According to at least one example embodiment, the floater is configured to be displaced in at least the vertical direction by greywater being accumulated within the first sub-enclosure.

[0048] Thus, as greywater is accumulated within the first sub-enclosure, the buoyancy of the greywater displaces the floater at least in the vertical direction. This displacement can either be directly or indirectly observed by a user of the system, whereby a simple and robust indication is provided.

[0049] According to at least one example embodiment the drain system further comprises a cover plate covering the first drain system inlet and the second drain system inlet, wherein the indicator is configured to be arranged through an indicator opening in the cover plate to provide the user with an indication of greywater flowing in the by-pass conduit.

[0050] Hereby, the user can receive a direct visible indication that the indicator has been activated, while at the same time hiding the indicator during normal use, in which no greywater flows through the by-pass conduit. For example, and with reference to the previously mentioned base portion comprising the planar horizontal surface, the cover plate and the planar horizontal surface may be parallel. That is, the cover plate may extend in a horizonal plane in parallel to the planar horizontal surface, wherein the cover plate is arranged at a vertical distance from the planar horizontal surface.

[0051] Thus, the indicator is configured to be moved vertically along the direction of the vertical distance to reach the opening in the cover plate. With reference to the previously mentioned embodiment comprising a first sub-enclosure, the indicator is configured to be arranged through the indicator opening in the cover plate to provide the user with an indication of the amount of greywater flowing in the by-pass conduit, as greywater accumulates in the first sub-enclosure. For example, the indicator is configured to reach the indicator opening in the cover plate in response to that a predetermined amount of greywater is accumulated in the first sub-enclosure. Hereby, the amount of greywater flowing in the by-pass conduit may be indicated to the user.

[0052] According to at least one example embodiment, the indicator comprises a protruding member, such as a rod, arranged to protrude through the indicator opening of the cover plate. The rod is an example of a mechanical indicator and / or an optical indicator.

[0053] According to at least one example embodiment, the indicator comprises an indicator plate so that, when greywater causes the indicator to a position close to, or in, the indicator opening of the cover plate, the indicator plate is clearly visible to a user. The indicator plate is an example of a mechanical indicator and / or an optical indicator.

[0054] According to at least one exemplary embodiment, the indicator comprises an indicator plate having a plurality of distinguishable indicator plates (e.g. distinguishable colors, shapes or patterns) so that, when the indicator is present at the indicator opening of the cover plate, at least one of the distinguishable indicator plates is clearly visible to a user, each of the distinguishable indicator plates corresponding to an amount of greywater flowing through the by-pass conduit.

[0055] According to at least one example embodiment, the drain system further comprises drain manifold comprising a first manifold inlet arranged to receive greywater from the heat exchanger, a second manifold inlet arranged to receive greywater from the by-pass conduit by-passing the heat exchanger and a manifold outlet arranged to supply any received greywater to the drain system outlet.

[0056] Thus, in case of flooding, or in order to handle a flow of greywater exceeding the capacity of the heat exchanger or the heat recovery system comprising the heat exchanger, the drain system is configured to guide the greywater to the drain manifold and the drain outlet via the by-pass conduit.

[0057] The drain manifold may thus have a function of providing a structure capable of collecting various greywater flows and guiding them to a common drain outlet.

[0058] According to at least one example embodiment, the indicator is a mechanical indicator.

[0059] Hereby, a robust indicator can be achieved. For example, the previously mentioned floater is a mechanical indicator. The mechanical indicator, such as e.g. the floater, may be combined with an optical indicator as described in the present disclosure.

[0060] According to at least one example embodiment, the indicator is an indicator paper, the indicator paper being arranged below a transparent surface of the cover plate, so that a user is able to observe a change to the indicator paper induced by greywater flowing through the by-pass conduit. Thus, the indicator paper is an example of an optical indicator.

[0061] According to at least one example embodiment, the indicator is arranged in the second drain system inlet or in the by-pass conduit.

[0062] Hereby, apart from the indicator, no additional structure may be required in the drain system to indicate a greywater flow in the by-pass conduit. Thus, a construction with low complexity can be achieved.

[0063] According to at least one example embodiment, the indicator is arranged, such as at least partly arranged, in the space between the cover plate and the base portion (such as between the cover plate and the planar horizontal surface). According to one example embodiment, the indicator is arranged in the cover plate, e.g. by being integrated in the cover plate, or the indicator is at least partly arranged in the cover plate. The indicator may be arranged inside the previously mentioned enclosure, e.g. the first sub-enclosure, or outside of the enclosure. The indicator may e.g. be arranged to indicate the presence of water in the enclosure, such as e.g. the first sub-enclosure, but arranged outside of the enclosure. For example, the indicator may be arranged outside of the enclosure at the same height as the first side wall.

[0064] According to at least one example embodiment, the indicator is an electronic indicator, preferably a battery driven electronic indicator.

[0065] Hereby, an indicator can be provided which allows flexibility with regards to its placement, as a sensor part of the indicator can be arranged hidden from a user. Furthermore, an electronic indicator can in some cases provide a more reliable indication of the greywater flow in the by-pass conduit. The electric indicator may e.g. be arranged in the previously mentioned enclosure, such as e.g. the first sub-enclosure. According to at least one example embodiment, the indicator is a mechanical indicator and / or an electrical indicator arranged in the enclosure, such as e.g. the first sub-enclosure. According to at least one example embodiment, the electrical indicator is arranged outside of the previously mentioned enclosure, but is configured to indicate the presence of water inside the enclosure, such as e.g. inside the first sub-enclosure. For example, the electrical indicator is a radar sensor, or a radar level measuring device. The radar sensor may e.g. be configured to transmit a radar signal by an antenna system of the radar sensor to the enclosure, whereby by the radar signal is reflected by the water surface in the enclosure (or of the first sub-enclosure), and be configured to receive the reflected radar signal by the antenna system. The time from emission to reception of the radar signal is proportional to the water level in the enclosure (or of the first sub-enclosure). Such radar sensor may e.g. be arranged in the cover plate, or on a surface of the cover plate facing the enclosure.

[0066] According to one embodiment, the electronic indicator comprises a water detector arranged in the by-pass conduit or at the second drain system inlet to indicate that greywater is flowing into the by-pass conduit.

[0067] According to one embodiment, the electronic indicator comprises a flow sensor to indicate the greywater flow rate in the by-pass conduit.

[0068] According to at least one example embodiment, the indicator is configured to indicate the presence of water, such as greywater, and / or is configured to indicate a flowing water, such as a flow of greywater.

[0069] According to at least one example embodiment, the indicator is an optical indicator, arranged to be visual for a user of the drain system. The optical indicator is typically configured to indicate the presence of water, such as greywater, and / or is configured to indicate a flowing water, such as a flow of greywater. The optical indicator may advantageously be combined with the previously mentioned electrical indicator and / or the mechanical indicator, such as e.g. the floater.

[0070] According to at least one example embodiment, the indicator is a combination of at least two of the previously mentioned types of indicators, i.e. a combination of at least two of: a mechanical indicator, an electrical indicator and an optical indicator. For example, the previously mentioned floater being a mechanical indicator may be provided with a visual indicator to indicate the position of the floater to a user.

[0071] Thus, the indicator may be a mechanical indicator, an electronic indicator, an optical indicator, or a combination thereof.

[0072] According to at least one example embodiment, the indicator comprises, or is comprised of, smart materials such as e.g. thermochromic, hydrochromic and / or shape shifting materials. Such smart materials may e.g. be actuated by the presence of water, or water at a predetermined temperature. Such indicator comprising smart materials may preferably be arranged in the cover plate.

[0073] According to a second aspect of the present invention, A shower or shower cabin is provided. The shower or shower cabin comprising:

[0074] a shower arrangement having a shower mixer configured to mix hot water from a hot water supply and pre-heated cold water from a cold-water supply, and a shower head fluidly connected to the shower mixer for supplying shower water;

[0075] a drain system according to the first aspect of the invention.

[0076] Effects and features of the second aspect of the invention are largely analogous to those described above in connection with the first aspect of the invention. Embodiments mentioned in relation to the first aspect of the invention are largely compatible with the second aspect of the invention, of which some are exemplified below.

[0077] The shower or shower cabin may comprise a shower floor or a shower tray, or alternatively be replaced with a shower tray (i.e. a shower cabin without the enclosing walls). The drain system of the first aspect of the invention may e.g. be integrated into such shower floor or shower tray.

[0078] Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0079] These and other aspects of the present inventive concept will now be described in more detail, with reference to the appended drawings showing an example embodiment of the inventive concept, wherein:

[0080] FIG. 1 schematically illustrates a shower or shower cabin comprising a drain system for recovering thermal energy from a flow of greywater, in accordance with at least some example embodiments of the invention;

[0081] FIG. 2 illustrates an embodiment of the drain system of FIG. 1 according to at least one example embodiment of the invention,

[0082] FIG. 3 illustrates at least parts of the drain system of FIG. 1 in more detail, according to at least one example embodiment of the invention,

[0083] FIG. 4 illustrates details of a drain system according to at least one example embodiment of the invention,

[0084] FIG. 5 illustrates details of a drain system according to at least one example embodiment of the invention, and

[0085] FIG. 6 is a cross section view illustrating further details of a drain system according to at least one example embodiment of the invention.DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0086] In the present detailed description, various embodiments of the invention are described mainly with reference to a shower (or shower cabin) comprising a drain system for recovering thermal energy from a flow of greywater.

[0087] FIG. 1 is a schematic view illustrating a shower or shower cabin 1. The shower or shower cabin 1 comprises a shower tray or shower floor 3, and shower walls 5 (of which only one shower wall is shown). The shower walls 5 are either attached to the building in which the shower 1 is installed or are separated from the building and thus forming part of a shower cabin 1.

[0088] Correspondingly, the shower tray or floor 3 is either attached to the building (i.e. constituting a shower floor of a shower), or is separated from the building (i.e. constituting a shower tray of a shower cabin). For simplicity, the shower or shower cabin 1 will in the following be described simply as a shower 1, and the shower tray or floor 3, as a shower floor 3.

[0089] The shower 1 comprises a shower mixer 10 and a shower head 12, the shower head 12 being fluidly connected to the shower mixer 10 by a shower conduit 14, being for example a shower hose or shower pipe. The shower mixer 10 is configured to mix hot water from a hot water supply, e.g. a hot tap water supply, and pre-heated cold water from a cold water supply, the latter being pre-heated cold water from a heat exchanger 70 in a drain system 30 as will be described in the following. During use, the shower mixer 10 mixes the desired amount of pre-heated cold water and hot water, supplies the mixed water to the shower head 12 via the shower conduit 14, whereby shower water for showering is provided. The shower water subsequently encounters the shower floor 3, and enters the shower drain system 30 as greywater. The greywater typically comprises debris, such as textile fibers and hair, as well as grease and shower products, as a result of the showering.

[0090] In the embodiment of FIG. 1, the drain system 30 is arranged in a pocket of the shower floor 3, wherein the pocket is covered with a cover plate 7 (shown better in the embodiment of FIG. 5), and wherein the cover plate 7 is provided with at least one opening, e.g. in the form of a plurality of punched holes 9a (shown in FIG. 5 only). However, it should be noted that the at least one opening may instead of a plurality of punched holes 9a be comprised of one or more gaps or slits arranged in the cover plate 7, for example one or more gaps or slits arranged along one or more of the lateral sides of the cover plate 7. Thus, the greywater may enter the drain system 30 via the at least one opening in the cover plate 7.

[0091] The drain system 30 comprises a first drain system inlet 32 for receiving greywater entering the drain system 30 and a drain system outlet 136 for discharging greywater to a drain 160, and subsequently to sewage. Moreover, the heat exchanger 70 comprises a greywater inlet 72 arranged downstream of the first drain system inlet 32 and being configured to receive greywater from the drain system inlet 32. The heat exchanger 70 further comprises a grey water outlet 74 arranged upstream of the drain system outlet 136, and being configured to receive greywater from the greywater inlet 72, and to discharge greywater to the drain system outlet 160.

[0092] The drain system 1 further comprises a second drain water inlet 133 for receiving greywater, and a by-pass conduit 138 arranged downstream of the second drain water inlet 133 and upstream of the drain 160. Thus, the by-pass conduit 138 is configured to received greywater form the second drain water inlet 133 and to discharge the greywater to the drain 160, possibly via the drain system outlet 136. The by-pass conduit 138 is adapted to provide a greywater by-pass of the heat exchanger 70, and the heat recovery system comprising the heat exchanger 70. Such heat recovery system may e.g. be defined to extend from the first drain system inlet 32 to the drain system outlet 136, via the heat exchanger 70, e.g. including conduits and / or filters. In the embodiment of FIG. 1, the by-pass conduit 138 is arranged to supply greywater to the drain system outlet 136 instead of, or in addition to, guiding greywater via the first drain system inlet 32 and the heat exchanger 70. Thus, in case of flooding, or in order to handle a flow of greywater exceeding the present capacity of the heat exchanger 70, the drain system 30 is configured to guide the greywater to the drain 160 via the by-pass conduit 138. The by-pass conduit 138 may be referred to as a by-pass pipe.

[0093] During use, greywater flowing into the drain system 30 is received by the first drain system inlet 32 and transported to the grey water inlet 72 of the heat exchanger 70. In the heat-exchanger 70, the greywater heats a flow of incoming cold water from a cold-water supply. Subsequently, the greywater flows out from the heat-exchanger 70 though the greywater outlet 74, and is discharged via the drain system outlet 136 to the drain 160 or sewage. In some cases, the amount of greywater in the drain system 30 exceeds the present capacity of the heat exchanger 70 and / or of the heat recovery system comprising the heat exchanger 70. For example, the inflow of greywater to the drain system 30 is increased, or the flow of greywater through the heat exchanger 70 is reduced, e.g. due to clogging of the heat exchanger 70 or of the heat recovery system as a result of the accumulation of debris, such as textile fibers, hair, grease and / or shower products. This may cause the greywater level within the drain system 30 to rise, and as a result the greywater will, in addition to being received by the first drain system inlet 32, be directed to the second drain system inlet 133 and the by-pass conduit 138. The greywater being received by the by-pass conduit 138 is directed to the drain system outlet 136 (or directly to the drain 160) without passing through the heat exchanger 70.

[0094] Turning briefly to FIG. 2, showing an alternative embodiment of the drain system30 of FIG. 1. Thus, like numbers refer to like elements without necessarily re-introducing them in the drain system 130 of FIG. 2. The drain system 130 of FIG. 2 comprises a drain manifold 180 arranged upstream of the drain system outlet 136. The drain manifold 180 comprises a first manifold inlet 182 arranged downstream of the heat-exchanger 70, and a manifold outlet 184 arranged to supply any received greywater to the drain 160. In the embodiment of FIG. 2, the manifold outlet 184 and the drain system outlet 136 are the same (i.e. the coincide). The drain 160 is only shown symbolically. The by-pass conduit 138 is arranged to supply greywater to a second manifold inlet 186 so that the drain system 130 may be configured to instead of, or in addition to, guiding greywater via the first drain system inlet 32 and the heat exchanger 70 to the drain manifold 180, guide greywater via the second drain system inlet 133 and the by-pass conduit 138 to the drain manifold 180 without passing through the heat exchanger 70. Thus, in case of flooding, or in order to handle a flow of greywater exceeding the present capacity of the heat exchanger 70, the drain system 130 is configured to guide the greywater to the drain manifold 180 via the by-pass conduit 138. In other example embodiments, the drain manifold 180 could be omitted, allowing the greywater to flow directly to the drain system outlet 136 or drain 160.

[0095] In the following, the drain system 30 will be described in further detail with additional reference to FIG. 3, in which details of the drain system 30 being arranged vertically below the cover plate 7 is shown in greater detail. In FIG. 3, the first drain system inlet 32 and the second drain system inlet 133 are shown. As shown in FIG. 3, the first drain system inlet 32 may be surrounded by one or more filters 33 configured to filter debris and the like prior to that the greywater reaches the first drain system inlet 32. The second drain system inlet 133 is arranged within an enclosure 22 delimited by a first side wall 23a. The first side wall 23a typically extends from a base portion 31 of the drain system 30, the base portion 31 comprising a planar horizontal surface 31a wherein the first side wall 23a extends vertically from the planar horizontal surface 31a. A height of the first side wall 23a is referring to the extension of the first side wall 23a in such vertical direction. The planar horizontal surface 31a may be a greywater collecting surface configured to receive greywater from the shower 1, wherein the first drain system inlet 32 and second drain system inlet 133 are formed as openings in the planar horizontal surface 31a. Owing to the first side wall 23a, greywater will, during normal operation of the drain system 30, flow into the first drain system inlet 32 and the heat exchanger 70, and not into the second drain system inlet 133 and the by-pass conduit 138. However, as previously described, in case the inflow of greywater to the drain system 30 is increased, or the flow of greywater through the heat exchanger 70 or of the heat recovery system comprising the heat exchanger 70 is reduced, the greywater level will rise to allow greywater to flow over the first side wall 23a and into the second drain system inlet 133 and the by-pass conduit 138. In other words, the height of the first side wall 223a is sized such that, in use, greywater flows into the first drain system inlet 23 rather than (or before) flowing into the second drain system inlet 133. Thus, and as shown in FIG. 3, the first drain system inlet 32 and second drain system inlet 133 are arranged on opposite sides of the first side wall 23a. Thus, the first drain system inlet 32 is arranged outside of the enclosure 22, and the second drain system inlet 133 is arranged inside of the enclosure 22.

[0096] FIG. 3 further schematically illustrates an indicator 20, 20′ arranged at the second drain system inlet 133. The indicator 20, 20′ can be a mechanical indicator 20′ and / or an electronic indicator 20 and is arranged to indicate to a user that greywater is flowing through, or is expected to flow through, the by-pass conduit 138. Thereby, the user is given an indication that the flow of greywater through the heat exchanger 70 has reached, or has exceeded, its capacity, as in use, greywater is only allowed to flow into the by-pass conduit 138 when the level of greywater in the drain system 30 exceeds the height of the first side wall 23a as previously described. Thus, greywater is prevented from flowing into the second drain system inlet 133 and the by-pass conduit 138 as long as the level of greywater in the drain system 30 is lower than the height of the first side wall 23a. Thus, the indicator 20, 20′ will indicate a flow of greywater bypassing the heat exchanger 70 only as the greywater level exceeds the height of the first side wall 23a, and the greywater flows over the first side wall 23a and into the enclosure 22, activating the indicator 20, 20′. Thereafter, the greywater flows into the by-pass conduit 138. Moreover, as a result of the first side wall 23a, a sudden, but short, increase in the greywater flow into the drain system 30 causing the greywater level to increase (potentially exceeding the greywater flow capacity of the heat exchanger 70 and / or of the heat recovery system) may occur without activating the indicator 20, 20′, as the greywater level does not exceed the height of the first side wall 23a.

[0097] FIG. 4 illustrates an alternative embodiment of at least parts of the drain system 30 of FIGS. 1 and 3. Like numbers refer to like elements (e.g. the second drain system inlet 133). In FIG. 4, an enclosure 222 is delimited by a first side wall 223a correspondingly to the embodiment of FIG. 3. However, in FIG. 4, the enclosure 222 is further divided into a first sub-enclosure 222a and a second sub-enclosure 222b by a second side wall 223b, as compared to the embodiment of FIG. 3. Each one of the first and second side walls 223a, 223b extends vertically from the planar horizontal surface 31a correspondingly as previously described to the first side wall 23a of FIG. 3.

[0098] The height of the second side wall 223b extends in the same direction as the height of the first side wall 223a. The second side wall 223b extends into the enclosure 222 from the first side wall 223a. That is, the second side wall 223b extends horizontally, or in a horizontal direction, from a first portion of the first side wall 223a into the enclosure 222 to a second portion of the first side wall 223a. Thus, the first sub-enclosure 222a is delimited by the first side wall 223a and the second side wall 223b, and the second sub-enclosure 222b is delimited by the first side wall 223a and the second side wall 223b. The height of the first and second side walls 223a, 223b are sized such that, in use, greywater first flow into the first sub-enclosure 222a before reaching the second sub-enclosure 223b and the second drain system inlet 133.

[0099] An indicator, e.g. as the previously mentioned indicators 20, 20′ of FIG. 3, or indicator 200 of FIG. 5, is configured to be arranged in the first sub-enclosure 222a. The second sub-enclosure 222b houses the second drain system inlet 133. The second side wall 223b comprises a slot 224, which in FIG. 4 extends along the entire height of the second side wall 223b. The slot 224 is arranged to allow for greywater to flow from the first sub-enclosure 222a to the second drain system inlet 133 in the second sub-enclosure 222b. The slot 224 can be sized to allow a predetermined flow of greywater from the first sub-enclosure 222a to the second sub-enclosure 222b so that greywater flow out of the first sub-enclosure 222a into the second sub-enclosure 222b in a controlled manner. The first side wall 223a further comprises a guiding structure 225 configured to guide the indicator in relation to the first side wall 223a. The guiding structure 225 is in FIG. 4 exemplified as a vertically extending rib on an inner surface of the first side wall 223a facing the enclosure 222.

[0100] FIG. 5 illustrates an alternative embodiment of at least parts of the drain system 30 of FIGS. 1 and 3. Like numbers refer to like elements. In large, the embodiment in FIG. 5 is the same as the embodiment in FIG. 4, why the differences thereof are mainly described. In FIG. 5, the indicator 220 is shown in the first sub-enclosure 222a. A guiding structure 225′ is in this embodiment arranged on the indicator 220, in the form of a plurality of vertically extending ribs, instead of, or in addition to, the guiding structure 225 of the first side wall 223b of FIG. 4. The indicator 220 is a mechanical indicator in the form of a floater. The floater is arranged to be movable at least in the vertical direction in the first sub-enclosure 222a, guided by the guiding structure 225′ and / or the guiding structure 225.

[0101] With reference to both FIGS. 4 and 5, the first sub-enclosure 222a housing the indicator 220 is arranged upstream of the second drain system inlet 133. Thereby the indicator 220 may be activated by the presence of greywater, or a flow of greywater, in the first sub-enclosure 222a, prior to the greywater reaching the second sub-enclosure 222b and the second drain system inlet 133. The buoyancy of the greywater is utilized to activate the indicator 220. Thus, as greywater is accumulated within the first sub-enclosure 222a, the buoyancy of the greywater displaces the floater at least in the vertical direction. This displacement can either be directly or indirectly observed by a user of the drain system.

[0102] The indicator 220 in FIG. 5 may be arranged in the first sub-enclosure 222a to indicate the presence of greywater at a predetermined level of accumulated greywater in the first sub-enclosure 222a. This may e.g. be achieved by adapting the floating buoyancy of the indicator 220. In case the flow of greywater into the first sub-enclosure 222a decreases (e.g. in response to that the flow of greywater through the heat exchanger 70 is increased, or a reduced total flow of greywater into the drain system 30), the water level in the second sub-enclosure 222b will successively decrease as greywater flows out of the first sub-enclosure through the slot 224. The indicator 220 may thus indicate the lack of presence of greywater, or lack of flow of greywater, in the first sub-enclosure 222a, as the indicator 220 is reset.

[0103] FIG. 6 is a cross section side view of an alternative embodiment of at least parts of the drain system 30 of FIGS. 1 and 3. Like numbers refer to like elements. In large, the embodiment in FIG. 6 is the same as the embodiment in FIG. 5, why the differences thereof are mainly described. In FIG. 6 the indicator 220′, in the form of a floater, is arranged in the first sub-enclosure 222a. The floater 220′ of FIG. 6 comprises a first part 220a and a second part 220b, the first part 220a being movably adjustable in relation to the second part 220b. By adjusting the first part 220a of the floater 220′ in relation to the second part 220b of the floater 220′, the height of the floater 220′ can be adapted with regards to the variations in the installation space, e.g. with regards to the height of the first sub-enclosure 222a, or the distance to the cover plate 7. For example, the second part 220b may comprises an internal cavity comprising an internal thread, and the first part 220a may comprises a protrusion comprising an external thread, wherein the protrusion can be threaded into the internal cavity by interaction of the internal and external threads. Hereby, the first part 220a may be moved in the vertical direction relative to the second part 220b as the protrusion is threaded out of the internal cavity.

[0104] As further illustrated in FIG. 6, the cover plate 7 is parallel to the previously mentioned planar horizontal surface 31a. That is, the cover plate 7 extends in a horizonal plane in parallel to the planar horizontal surface 31a, wherein the cover plate 7 is arranged at a vertical distance from the planar horizontal surface. In addition to the punched holes 9a for receiving greywater into the drain system 30, the cover plate 7 comprises an indicator opening 71. In the embodiment of FIG. 6, the indicator 220′ comprises a protruding member, such as a rod 220c, arranged to protrude through the indicator opening 71 of the cover plate 7. The indicator 220′ is configured to be moved vertically along the direction of the vertical distance such that the rod 220c reaches the opening in the cover plate 7. The indicator 220′ is thus configured to reach the indicator opening 71 in the cover plate 7 in response to that a predetermined amount of greywater is accumulated in the first sub-enclosure 222a. Hereby, the amount of greywater flowing in the by-pass conduit 138 may be indicated to the user, as the rod 220c becomes visible at the indicator opening 71. The indicator opening 71 thus allows a user to receive a direct visible indication that the indicator 220′ has been activated. The presence of the indicator 220′ at the indicator opening 71 could also be detected without the provision of the rod 220c.

[0105] Even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art. For example, the drain system may be installed for heat recovery of greywater from a faucet, or a bathtub, instead of a shower.

[0106] Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A drain system for recovering thermal energy from a flow of shower or faucet greywater, the drain system comprising:a first drain system inlet for receiving greywater,a drain system outlet for discharging greywater to a drain,a heat exchanger comprising a grey water inlet arranged downstream of the drain system inlet, and a grey water outlet arranged upstream of the drain system outlet, the heat exchanger being configured to heat a flow of incoming cold water with the greywater flowing from the grey water inlet to the grey water outlet,a second drain system inlet for receiving greywater,a by-pass conduit arranged downstream of the second drain system inlet and upstream of the drain, the by-pass conduit being configured to provide a greywater by-pass of the heat exchanger, andan indicator configured to indicate a flow of greywater bypassing the heat exchanger in the by-pass conduit.

2. The drain system according to claim 1 further comprising a first side wall, the first side wall delimiting an enclosure housing the second drain system inlet, wherein the indicator is configured to be arranged within the enclosure.

3. The drain system according to claim 2, further comprising a second side wall extending into the enclosure to partition the enclosure into a first sub-enclosure and a second sub-enclosure, wherein the indicator is arranged in the first sub-enclosure and the second drain system inlet is arranged in the second sub-enclosure.

4. The drain system according to claim 3, wherein the second side wall comprises a slot, the slot being arranged to allow for greywater to flow from the first sub-enclosure to the second sub-enclosure.

5. The drain system according to claim 3, wherein the first side wall the second side wall and / or the indicator comprises a guiding structure configured to guide the indicator in relation to the first side wall and / or the second side wall.

6. The drain system according to claim 3, wherein the height of the first and second side walls are sized such that, in use, greywater first flow into the first sub-enclosure before reaching the second sub-enclosure and the second drain system inlet,7. The drain system according to claim 1, wherein the indicator comprises a floater.

8. The drain system according to claim 7, wherein the floater is arranged to be displaced in a vertical direction by greywater being accumulated within the first sub-enclosure.

9. The drain system according to claim 1, further comprising a cover plate covering the first drain system inlet and the second drain system inlet, wherein the indicator is configured to be arranged through an indicator opening in the cover plate to provide the user with an indication of greywater flowing in the by-pass conduit.

10. The drain system according to claim 1, further comprising a drain manifold comprising a first manifold inlet arranged to receive greywater from the heat exchanger a second manifold inlet arranged to receive greywater from the by-pass conduit by-passing the heat exchanger and a manifold outlet arranged to supply any received greywater to the drain system outlet.

11. The drain system according to claim 1, wherein the indicator is a mechanical indicator.

12. The drain system according to claim 1, wherein the indicator is arranged in the second drain system inlet or in the by-pass conduit.

13. The drain system according to claim 1, wherein the indicator is an electronic indicator.

14. A shower or shower cabin comprising:a shower arrangement having a shower mixer configured to mix hot water from a hot water supply and pre-heated cold water from a cold-water supply, and a shower head fluidly connected to the shower mixer for supplying shower water;a drain system according to claim 1.

15. The drain system according to claim 9, wherein the indicator comprises an indicator plate configured to, during use when greywater causes the indicator to a position close to, or in, the indicator opening of the cover plate, be clearly visible to a user.

16. The drain system according to claim 15, wherein the indicator plate comprises a plurality of distinguishable indicator plates, wherein each of the distinguishable indicator plates corresponds to an amount of greywater flowing through the by-pass conduit.

17. The drain system according to claim 9, wherein the indicator comprises a protruding member configured to protrude through the indicator opening if the cover plate.

18. The drain system according to claim 7, wherein the floater comprises a first part and a second part, the second part being movably adjustable relative to the first part to allow height customization.

19. The drain system according to claim 1, wherein the indicator comprises an electrical indicator configured to indicate the presence of water inside the enclosure.

20. The drain system of claim 1, wherein the indicator comprises a material selected from the group consisting of thermochromic, hydrochromic, and shape-shifting materials that are activated by greywater presence or temperature.

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