WO2024078709A1

WO2024078709A1 - Articles treatment machine with tank assembly

Info

Publication number: WO2024078709A1
Application number: PCT/EP2022/078370
Authority: WO
Inventors: Maurizio Del Pos; Pietro ROMANAZZI
Original assignee: Electrolux Appliances Aktiebolag
Priority date: 2022-10-12
Filing date: 2022-10-12
Publication date: 2024-04-18

Abstract

Articles treatment machine with tank assembly The invention provides an articles treatment machine. The machine (2), in particular a dishwasher, comprises: a cabinet, a tub (8) for washing articles therein and being arranged in the cabinet, a sump (20) for collecting washing liquid from the tub (8), a circulation pump (24), a softener assembly (40) adapted to softening water flowing therethrough, a tank assembly (42) comprising a water tank (44) for storing fresh water and having a tank outlet (73), a heat exchanger (48), preferably a tube-in-tube heat exchanger, comprising a first passage (52) and a second passage (50) being in heat-exchanging contact with each other, a closed loop flow path (64) forming a flow circuit and comprising an inlet at the sump (20), the first passage (52) through the heat exchanger (48) and an outlet connected to the tub (8) or sump (20), wherein washing liquid is circulated along the closed loop flow path (64) via the circulation pump (24), and an inlet flow path (68) comprising an inflow connection to water mains (78), the softener assembly (40), the second passage (50) through the heat exchanger (48), the water tank (44) and the tank outlet (73) connected to the tub (8) or sump (20), wherein the second passage (50) is arranged downstream of the softener assembly (40) and upstream of the water tank (44).

Description

Articles treatment machine with tank assembly

The present invention relates to an articles treatment machine, in particular a dishwasher, having a tank assembly.

WO 2020/249224 Al discloses a dishwasher having a tank and a heat exchanger, wherein fresh water exchanges heat in the heat exchanger with washing liquid drained from the sump of the dishwasher via a drain water conduit. The heated fresh water may be stored in the tank.

It is an object of the invention to provide an articles treatment machine with an improved efficiency.

The invention is defined in independent claim 1. Particular embodiments are set out in the dependent claims.

According to claim 1, an articles treatment machine, in particular a dishwasher, is provided. The treatment machine comprises a cabinet, a tub for washing articles therein and being arranged in the cabinet, a sump for collecting washing liquid from the tub, a circulation pump, a softener assembly adapted to softening water flowing therethrough, a tank assembly comprising a water tank for storing fresh water and having a tank outlet, a heat exchanger, preferably a tube-in-tube heat exchanger, comprising a first passage and a second passage being in heat-exchanging contact with each other, a closed loop flow path forming a flow circuit and comprising an inlet at the sump, the first passage through the heat exchanger and an outlet connected to the tub or sump, wherein washing liquid is circulated along the closed loop flow path via the circulation pump, and an inlet flow path comprising an inflow connection to water mains, the softener assembly, the second passage through the heat exchanger, the water tank and the tank outlet connected to the tub or sump, wherein the second passage is arranged downstream of the softener assembly and upstream of the water tank. In the closed loop flow path, washing liquid from the sump is circulated through the first passage of the heat exchanger and may be guided back into the tub or sump. During circulation along the closed loop flow path, the washing liquid preferably does not contact the articles loaded within the machine. Thus, the whole or substantially the whole heat stored within the washing liquid can be exchanged in the heat exchanger.

In the inlet flow path, fresh water from the inflow connection to water mains is guided through the softener assembly and the second passage of the heat exchanger and heated softened water can be collected in the water tank. Under respective control the heated softened water in the water tank can be supplied via the tank outlet into the tub or sump. The fresh water flowing through the second passage of the heat exchanger can be heated up by exchanging heat with the washing liquid from the sump flowing in the closed loop flow path through the first passage of the heat exchanger.

Thus, the residual heat within the washing liquid in the sump can be reused by transferring the heat to the fresh water which can then be stored in the water tank until it is used for a further washing cycle or for a next phase within the same washing cycle. This improves the overall efficiency of the machine.

The heat exchanger and the water tank are preferably arranged next to each other. In particular, when considering the assembled state of the machine, the heat exchanger is arranged on one of the lateral sides of the water tank.

The closed loop flow path and the inlet flow path are preferably fluidly separated from each other, i.e. no fluid flowing through the closed loop flow path can flow into the inlet flow path and vice versa. Fresh water can be filled into the water tank via the inlet flow path. Thus, no dirty washing liquid from the sump flows into the water tank, but only fresh water, in particular, heated softened fresh water is collected in the water tank when the heat exchange mode is activated.

A tank valve (e.g. an on/off valve) may be arranged downstream of the water tank, in particular at the tank outlet such that the water tank can be kept filled with the fresh water or the water tank can be emptied completely or at least partially by control of the tank valve. When emptying the water tank, the fresh water flows from the tank outlet into the sump.

Preferably, a water inlet valve is arranged between the inflow connection to water mains and the softener assembly which is configured to control the fresh water flow into the treatment machine. Preferably, the water inlet valve is configured to apply a fresh water inlet flow rate less than 2,4 liters/min, for example in the range between 1,5-2 liters/min, 1, 6-2,1 liters/min or 1,7-2, 2 liters/min. This increases the time spent by fresh water in the heat exchanger, thus increasing the amount of heat recovered.

A high rotational speed of the circulation pump circulating the washing fluid along the closed loop flow path may create a critical waterjet exiting the tub connection of the closed loop path, with the risk of hitting the dishes close to such connection. Preferably, the rotational speed of the circulation pump is reduced compared to common rotation speeds such that the washing fluid does not contact the dishes to be washed and thus the dishes are not cooled by the washing fluid.

Preferably, for improving the heat exchange in the heat exchanger, warm washing liquid from the sump is circulated through the closed loop flow path and at the same time fresh water is filled into the water tank via the inlet flow path. When the water tank is completely or substantially completely filled, supplying of the fresh water and the circulation along the closed loop flow path is preferably stopped. Then, the remaining washing liquid in the sump can be drained via a drain pump. The heated fresh water within the water tank may be supplied into the sump for a subsequent wash cycle or next phase within the same wash cycle.

The machine may comprise a flow controller adapted to guide the washing liquid from the sump to one of, two of or any of a bottom, middle and top spray arm via a circulation pump.

The circulation pump for circulation of the washing liquid from the sump along the closed loop flow path may be the same pump as the circulation pump for circulating the washing liquid within the tub from the sump to the respective spray arms via the flow controller.

The flow controller may comprise an additional outlet connected to the first passage of the heat exchanger such that the washing liquid is guided along the closed loop flow path for heat exchange with fresh water. In this case the washing liquid from the sump flows through the additional outlet of the flow controller and from the additional outlet to the heat exchanger.

The flow controller may include a positioning device and a disk rotatably arranged in relation to the plurality of washing fluid outlets (for the spray arms) and the at least one extra outlet, wherein the disk comprises a plurality of apertures arranged for selectively closing and opening the plurality of washing fluid outlets and/or the at least one extra outlet of the sump during rotation of the disk. When the positioning device aligns at least one of the plurality of apertures of the disk with the at least one extra outlet of the sump, washing fluid is permitted to pass from the flow controller via the extra outlet to the first passage of the closed loop path, the other washing fluid outlets being closed so that no washing fluid flows through spray devices arranged in the tun of the dishwasher.

Alternatively, one circulation pump may be provided for circulation liquid from the sump through the respective spray arms, and another circulation pump may be provided for circulation of the washing liquid from the sump along the closed loop flow path. In this case, the washing liquid from the sump is preferably not guided through a or the flow controller.

Preferably the tank assembly extends in a vertical plane and/or is arranged at a side wall of the treatment machine. Preferably the tank assembly is arranged at the outside of the tub of the machine.

The softener assembly is preferably arranged at least partially below the tank assembly. The softener assembly preferably comprises a salt and resin container, wherein the fresh water from the inflow connection to water mains is guided either through the resin container (for softening the fresh water), or, if a regeneration of the resin in the resin container is necessary, through the salt container and then through the resin container (or at least one part of the fresh water is guided through the salt container and then through the resin and another part is directly guided through the resin container). A valve element such as an ON/OFF valve may be provided upstream of the salt container. Thus, fresh water is only guided through the salt container if a regeneration of the resin within the resin container is necessary.

Preferably, the heat exchanger is a tube-in-tube heat exchanger comprising an inner tube forming the first (or the second) passage of the heat exchanger and an outer tube forming the second (or first) passage of the heat exchanger, and the inner tube having a smaller cross section is arranged within the outer tube having a larger cross section.

Preferably the outer cross section of the inner tube is completely received in the outer tube and a free space is around the inner tube to enable a flow in the outer tube around the inner tube and/or the inner tube is a tube inserted into the outer tube after manufacturing at least a portion of the outer tube.

The inner tube of the heat exchanger is preferably a separate element that is mounted within the outer tube. For example, the inner tube may be made of a plastic. Preferably, the inner tube is made of a metal material. Thus, the heat exchange is increased. The outer tube is preferably made of a plastic material. The outer tube may comprise spacer elements arranged within the outer tube for ensuring the centering of the inner tube. Thus, flow unbalances can be prevented and a uniform heat exchange is achieved. The flow direction of the liquid flowing in the inner tube and of the liquid flowing in the outer tube may be co-current or in counterflow.

Preferably the first passage of the heat exchanger, which is part of the closed loop flow path, is formed by the inner tube of the heat exchanger and thus guides the circulated washing liquid. Alternatively or additionally, the second passage of the heat exchanger, which is part of the inlet flow path, is formed by the free space between the outer tube and the inner tube of the heat exchanger and thus guides the fresh water supplied from the inflow connection to water mains (preferably via the softener assembly) into the water tank.

Preferably, the first and/or second passages of the heat exchanger is/are formed integrally with the water tank, and/or a or the outer tube of the heat exchanger is formed integrally with the water tank.

'Formed integrally ' may mean that the water tank and the first and/or second passages and in particular the outer tube of the heat exchanger, are made in a single piece. For example, the water tank and the first and/or second passage, and in particular the outer tube, are made by injection molding.

When considering the normal operation position of the machine, the tank assembly may be divided vertically into a first part (e.g. a shell element) and a second part (e.g. a cover element), wherein both parts may be attached permanently to each other during assembly by e.g. by (ultrasonic) welding.

By permanently connecting both halves, the water tank and fluid channels arranged within the tank assembly are formed. I.e. the water tank and each fluid channel arranged within the tank assembly are preferably formed after the connection of the first and second part of the tank assembly. In this case, one part of the first and/or second passage of the heat exchanger may be integrally formed with the first part of the tank assembly and another part of the first and/or second passage of the heat exchanger may be integrally formed with the second part of the tank assembly. Preferably, the tank assembly and in particular the fluid paths and/or inlets and outlets comprised in the tank assembly, is/are made of plastic.

Preferably, the tank assembly comprises a flow channel being part of the inlet flow path, wherein the flow channel connects the outlet of the second flow passage of the heat exchanger to an inlet of the water tank, wherein preferably the flow channel is formed integrally with the water tank. The flow channel preferably extends in a vertical plane. Preferably the inlet of the water tank is arranged at a top region of the water tank.

The treatment machine may comprise a bypass conduit being part of the inlet flow path, wherein the bypass conduit is arranged downstream of the softener assembly and upstream of the heat exchanger and is connected to an outlet connected to the sump or tub.

Fresh water supplied from the inflow connection to water mains can be guided along the bypass conduit while bypassing the heat exchanger. Thus, it is possible to supply fresh water to the tub without guiding the fresh water through the heat exchanger and the water tank.

The treatment machine may comprise a control unit. The control unit is preferably adapted to selectively guide the fresh water via the outlet of the bypass conduit into the sump or tub and/or via the heat exchanger into the water tank.

Thus, exclusively fresh water may only be guided through one of the passages of the heat exchanger and stored in the water tank if heat exchange with the washing liquid from the sump is desired or if it is desired to fill the water tank with fresh water for a next cycle. Otherwise, the fresh water is guided along the bypass conduit bypassing the heat exchanger.

The tank assembly may comprise several different operation modes:

A passive heat exchange mode: In this case cold fresh water (e.g. 15°C) stored in the water tank may be heated up over several hours by absorbing ambient heat from the surroundings (to e.g. 23°).

An active heat exchange mode: Washing liquid is flowing along the closed loop flow path and through the first passage of the heat exchanger and fresh water is flowing along the inlet flow path and the second passage of the heat exchanger while the washing liquid exchanges heat with the fresh water within the heat exchanger. This mode may be applied e.g. at the end of the pre-wash, wash phase and/or the cold rinse before draining of the washing liquid in the sump. Thus, the residual heat from the washing liquid can be transferred to the fresh water and can be reused in a next washing cycle, e.g. a hot rinse. Therefore, the energy efficiency of the machine is improved.

A quick clean program: If it is necessary to fill up the sump faster and/or if the water stored in the tank is not enough to properly operate the circulation pump, the fresh water can be directly guided into the tub or sump via the bypass conduit bypassing the heat exchanger and the water tank.

The bypass conduit may be arranged external to the tank assembly for guiding fresh water into the sump or at least a portion of the bypass conduit may be comprised in the tank assembly for guiding fresh water into the tub via a tub outlet.

Preferably, at least a portion of the bypass conduit is arranged within the tank assembly and the outlet of the bypass conduit is a tub outlet arranged within the water tank. Preferably, the portion of the bypass conduit is formed integrally with the water tank.

At least a first part of the portion of the bypass conduit preferably extends next to the water tank from the bottom to the top, wherein a second part extends through the water tank to the tub outlet arranged within the water tank.

The tank assembly may comprise a return channel being part of the closed loop flow path, wherein the return channel connects the outlet of the first passage of the heat exchanger to the outlet connected to the tub or sump. The return channel is preferably formed integrally with the water tank. Preferably, the return channel is arranged between the heat exchanger and the water tank.

Preferably, the outlet of the closed loop flow path is a tub outlet arranged in proximity to or being at least partially surrounded by the water tank of the tank assembly. The tub outlet may be arranged at a side wall of the treatment machine. In case the tub outlet is at least partially surrounded by the water tank, the return channel guiding the washing liquid to the tub outlet may extend at least partially through the water tank.

The fluid connection from the outlet of the heat exchanger to the tub outlet is preferably a closed fluid connection without any connection to the fresh water stored within the water tank. I.e. the tub outlet arranged within the water tank is also preferably fluidly separated from the water tank (i.e. no fluid connection between water tank and tub outlet).

Preferably, the outlet of the closed loop flow path is fluidly connected to the tub and is forming a common outlet to the tub with the outlet of the bypass conduit. An outlet of an overflow conduit (described below) may also be the same outlet as the outlet of the closed loop flow path and the bypass conduit. I.e. in this case heated softened fresh water from the overflow conduit, washing liquid from the closed loop flow path and softened fresh water from the bypass conduit are guided via a common outlet to the tub. The tank assembly may comprise a draining path connected to an inlet at the sump, wherein the draining path is adapted to drain, using a drain pump, washing liquid from the sump out of the treatment machine. Preferably a portion of the draining path is formed integrally with the water tank.

The draining path is preferably arranged next to the heat exchanger, preferably at a side of the heat exchanger facing away from the water tank.

The draining path may comprise a siphon or air gap for preventing dirty water to flow back into the machine. In particular, the draining path may extend from the bottom to a top or upper region of the tank assembly and from the top or upper region to the bottom of the tank assembly, wherein the siphon/air gap is provided at the top portion of the draining path.

Thus, when the drain pump for draining the washing liquid is stopped, the remaining dirty washing liquid within the draining path preferably flows out of the draining path due to gravity. When the draining path has a clog or blockage downstream of the air gap, no dirty water can flow from the outside of the machine back into the machine via the draining path due to the siphon/air gap.

Preferably the inlets and outlets of the tank assembly are arranged at a bottom region of the tank assembly, and/or the tank assembly and the inlets and outlets of the tank assembly extend in a vertical or substantially vertical plane.

In particular an inlet and outlet of the draining path and/or the tank outlet and/or the inlets of the first and/or second passage of the heat exchanger and/or an inlet of the bypass conduit guiding fresh water to the tub outlet bypassing the heat exchanger are arranged at the bottom region of the tank assembly. If available, an inlet and outlet (or two outlets one connected to the salt container and the other connected to the resin container) of an air gap flow conduit comprising an air gap/break (described below) is preferably also arranged at the bottom region of the tank assembly.

The tank assembly may comprise an overflow conduit connected to a tub outlet and arranged within the water tank such that fresh water within the water tank exceeding a maximum water fill level is guided back into the tub via the overflow conduit. Preferably, the overflow conduit is formed integrally with the water tank. Preferably, the outlet of the overflow conduit is formed by a tub outlet which is arranged within the water tank. The tub outlet is preferably the same tub outlet that is connected to the return channel of the closed loop flow path and/or the tub outlet to which the bypass conduit is connected.

The overflow path is preferably arranged within a center of the water tank, wherein the inlet of the overflow path extends from a maximum water level to the tub outlet.

Preferably, the tank assembly comprises an air gap flow conduit being part of the inlet flow path and being arranged downstream of the inflow connection to water mains and upstream of the softener assembly, wherein the air gap flow conduit comprises an air gap. The air gap flow conduit is preferably formed integrally with the water tank.

The air gap is preferably arranged at or above the maximum water level of the water tank. The inlet and outlet (or two outlets one connected to the salt container and the other connected to the resin container) of the air gap flow conduit are preferably arranged at the bottom region of the tank assembly. I.e. the air gap flow conduit extends from the bottom to the top or upper region of the tank assembly, at least to the maximum water level where the air gap is arranged and from there back to the bottom region of the tank assembly.

When considering the normal operation position of the tank assembly, the air gap flow conduit is preferably arranged on a lateral side of the tank assembly, e.g. adjacent to the water tank.

The air gap is preferably in fluid communication with the water tank such that water leakage at the air gap flows into the water tank. When fresh water is supplied with a predetermined pressure along the first circulation, most of the water passes through the air gap. However a little leakage of water may be present. Since the air gap is preferably fluidly connected to the water tank, the water leakage at the air gap may flow due to gravity into the water tank.

The treatment machine may further comprise a valve arrangement which is arranged in the inlet flow path downstream of the water mains and upstream of the heat exchanger. The valve arrangement may comprise a housing with two valve inlets and at least two valve outlets, wherein a first valve inlet of the two valve inlets is fluidly connected to an outlet of the softener assembly, a second valve inlet of the two valve inlets is fluidly connected to the tank outlet, a first valve outlet of the two valve outlets is fluidly connected to the sump or the tub, wherein preferably the fresh water flowing via the first valve outlet out of the valve arrangement bypasses the heat exchanger (via the bypass conduit as described above and below), and a second valve outlet of the two valve outlets is connected to the second passage of the heat exchanger. The control unit may be adapted to control the valve arrangement such that it is switched to different switching states, wherein the fresh water is guided in each of the switching states along at least one of different flow paths.

Within its housing the valve arrangement integrates the function of guiding the softened water from the softener to different flow paths and the function of emptying the water tank by guiding the fresh water from the water tank into the sump.

“Valve arrangement” may be any device which is configured to direct the fresh water flowing through the two valve inlets into the housing and via the at least two valve outlets out of the housing along different flow paths. The valve arrangement may comprise a plurality of valves, or may comprise a (preferably rotatable) distributor which is configured to guide the fresh water along different flow paths depending on the rotation position of the distributor. Different switching states may mean that valves are controlled or that a rotatable distributor is rotated in specific rotation positions, wherein each rotation position connects the valve inlets and valve outlets of the valve arrangement differently.

By providing a valve arrangement integrating both functions in one housing, the installation of the valve arrangement and the tank assembly is facilitated and assembling and maintenance time is optimized.

The housing may comprise a cover element for closing the housing. In particular the cover element may form fluid paths within the housing when being mounted. The cover element may be connected to the housing by e.g. welding. Thus, a watertight connection can be achieved and leakage of water at the housing can be prevented. The housing preferably extends (or is arranged) in a horizontal or substantially horizontal plane when considering the normal operation position of the machine.

The valve arrangement may comprise the following switching states: a first switching state in which fresh water flows from the first valve inlet to the first valve outlet, a second switching state in which fresh water flows from the first valve inlet to the second valve outlet, a third switching state in which fresh water flows from the second valve inlet to the first valve outlet, and optionally a fourth switching state in which fresh water flows from the first valve inlet to the second valve outlet and fresh water flows from the second valve inlet to the first valve outlet. The control unit may be adapted to selectively control the valve arrangement such that it is switched to the selected one of the switching states. Only one of the switching states can be assumed by the valve arrangement at a time such that preferably only (exclusively) the fluid connection as defined for the switching state is established.

In the first switching state fresh water from the softener is guided to the sump or tub, wherein the heat exchanger is bypassed. In the second switching state fresh water from the softener is guided to the heat exchanger and into the water tank. In the third switching state heated softened fresh water from the water tank is guided to the tub or sump. In the optional fourth switching state fresh water from the softener is guided to the heat exchanger and into the water tank and at the same time water from the water tank is guided to the sump or tub.

In the first and third switching states, the water is preferably guided via a common valve outlet, namely the first valve outlet out of the valve arrangement to the sump or tub.

Alternatively, the valve arrangement may comprise three valve outlets (instead of only two valve outlets). In this case, the first valve outlet is connected to the tub, in particular the tub outlet, via the bypass conduit (as described above and below) guiding softened water received from the softener assembly via the first valve inlet into the tub while bypassing the heat exchanger, the second valve outlet is connected to the heat exchanger guiding the softened water to the second passage of the heat exchanger and into the water tank, and a third valve outlet is connected to the sump and guides water from the water tank into the sump.

The valve arrangement may comprise or may be a rotatable distributor having at least two flow paths, wherein the distributor is rotatable such that in a or the first switching state one of the flow paths provides a fluid connection from the first valve inlet to the first valve outlet, in a or the second switching state one of the flow paths provides a fluid connection from the first valve inlet to the second valve outlet, in a or the third switching state one of the flow paths provides a fluid connection from the second valve inlet to the first valve outlet, and optionally in a or the fourth switching state one of the flow paths provides a fluid connection from the first valve inlet to the second valve outlet and another of the flow paths provides a fluid connection from the second valve inlet to the first valve outlet.

The rotatable distributor is preferably connected to a motor for rotating the distributor. A position detector may be provided at the distributor for detecting the rotation position of the distributor. Each switching state preferably corresponds to a specific rotation position of the distributor which is detected by the position detector. The control unit may be adapted to control the motor such that the distributor is rotated to specific rotation positions corresponding to the switching states.

Preferably, only (exclusively) the fluid connection as defined for the switching state is established, i.e. in the first switching state there is no fluid connection between the second valve inlet and second valve outlet, in the second switching state there is no fluid connection between the second valve inlet and first valve outlet, and in the third switching state there is no fluid connection between the first valve inlet and second valve outlet.

Alternatively to the rotatable distributor, the following fluid paths are preferably arranged within the housing of the valve arrangement: a first fluid path connecting the first valve inlet to the first valve outlet such that fresh water from the softener assembly is guided to the sump or tub, a second fluid path connecting the first valve inlet to the second valve outlet such that the fresh water from the softener assembly is guided to the water tank via the heat exchanger, and a third fluid path connecting the second valve inlet to the first valve outlet such that fresh water from the water tank is guided to the sump or tub.

The first, second and third fluid paths are preferably arranged within the housing, more preferably are formed integrally with the housing. Preferably the fluid paths are not movable (compare above rotatable distributor).

The first and third fluid path may be connected to the same outlet, namely the first valve outlet. I.e. the flow path connected to the first outlet guides softened water from the softener assembly for bypassing the heat exchanger and water from the water tank into the sump or tub.

When the valve arrangement comprises three valve outlets as described above, the first fluid path guides water from the first inlet via the first valve outlet to the tub, the second fluid path guides water from the first inlet via the second valve outlet to the heat exchanger and water tank, and the third fluid path guides water from the second inlet via the third valve outlet to the sump. I.e. in this case the first, second and third fluid paths are fluidly separated from each other, each having its own outlet.

Preferably, the valve arrangement further comprises: at least one valve adapted to selectively guide fresh water along the first fluid path or the second fluid path, and a tank valve arranged in the third fluid path and being adapted to block or allow the flow of the fresh water out of the water tank into the tub or sump. Preferably, the at least one valve and the tank valve are integrated in the housing. Preferably, the fresh water inlet valve is integrated in the housing. 'Integrated’ preferably means that the housing, the at least one valve and the tank valve form a single unit. The at least one valve and/or the tank valve may be arranged within the housing or may be attached from the outside to the housing. Thus, assembly of the whole valve arrangement is simplified as the valve arrangement includes all components forming a single unit. Only fluid pipes have to be connected to the valve inlets and outlets of the valve arrangement.

Preferably, at least one of the following applies to the above switching states in case the valve arrangement comprises at least one valve and a tank valve:

In the first switching state only the first fluid path is in an open state and the second and third fluid paths are closed. In the second switching state only the second fluid path is in an open state and the first and third fluid paths are closed. In the third switching state only the third fluid path is in an open state and the first and second fluid paths are closed. In the fourth switching state the second fluid path and the third fluid path are in an open state and the first fluid path is closed.

Preferably, the at least one valve is a three-way valve, wherein the first fluid path arranged within the housing connects a first valve outlet of the three-way valve to the first valve outlet of the valve arrangement, wherein the second fluid path arranged within the housing connects a second valve outlet of the three-way valve to the second valve outlet of the valve arrangement, and wherein the housing preferably comprises a fourth fluid path connecting the outlet of the softener assembly to a valve inlet of the three-way valve. Preferably the three- way valve is attached to the outer surface of the housing, more preferably at the outer bottom surface of the housing when considering the normal operation position of the machine.

The first, second, third and fourth fluid paths are preferably arranged within the housing, more preferably are formed integrally with the housing.

Alternatively, the at least one valve comprises a first valve and a second valve, wherein the first valve is arranged in the flow path connected to the first valve outlet of the valve arrangement and the second valve is arranged in the flow path connected to the second outlet of the valve arrangement. By controlling the two valves with the control unit, the fresh water from the softener assembly can either be guided through the heat exchanger via the second valve outlet and/or directly into the tub/sump via the first valve outlet while bypassing the heat exchanger. The treatment machine further comprises a flow meter adapted to provide a signal indicating the amount of supplied fresh water, wherein the flow meter is arranged downstream of the inflow connection to water mains and upstream of the softener assembly. Preferably the flow meter is arranged upstream of the air gap flow conduit comprised in the inlet flow path as described above. The flow meter may be integrated in the valve arrangement, preferably in the housing of the valve arrangement. Preferably the housing comprises a fluid path in which the flow meter is arranged, and wherein the fluid path preferably comprises an inlet connected to the inflow connection to water mains and an outlet connected to an inlet of the softener assembly.

The flow meter may provide feedback for controlling either the amount of water reaching the water tank via the heat exchanger or the sump if the heat exchanger and the water tank are bypassed via the first valve outlet of the valve arrangement.

The valve arrangement may be integrated in the softener assembly, wherein preferably the valve arrangement is arranged at a side wall or at the top of the softener assembly.

The valve arrangement and the softener assembly may be fully integrated, i.e. with no visible physical separation between the softener element and the valve arrangement. Alternatively, the valve arrangement and the softener assembly can be detached from each other to have simpler modules consisting of only the softener assembly and the valve arrangement. In this case there are not only hydraulic quick connections between the valve arrangement /softener assembly and the tank assembly, but also between the valve arrangement and the tank assembly.

Preferably, all hydraulic connections facing upwards and/or laterally (i.e. there are no inlets and/or outlets at the bottom of the valve arrangement or the softener assembly). Thus the installation of the valve arrangement with the softener assembly and the tank assembly is facilitated and assembling and maintenance time is optimized.

Preferably, when the valve arrangement is integrated in the softener assembly, the height of the integrated assembly is kept the same as the vertical height of the softener assembly without integrated valve arrangement. Thus it can be ensured that the integrated assembly fits below the tub of the machine.

If the valve arrangement is arranged on top of the softener, the width and/or depth of the integrated assembly is preferably adapted such that the container volumes of resin and salt do not change or substantially not change. The valve arrangement is preferably arranged below the tub, and/or between the tank assembly and the sump and/or is arranged below the tank assembly.

In case the machine comprises a softener assembly as mentioned above, the valve arrangement is preferably arranged between the softener assembly and the sump. In case the valve arrangement is integrated with the softener assembly, the valve arrangement is preferably arranged below the tank assembly, in particular the valve arrangement is at least partially arranged vertically between the softener assembly and the tank assembly.

Any feature disclosed herein (for the above embodiments and/or configurations and from the below described detailed embodiments and modifications) can be combined with the claimed subject individually or in any sub-combination.

Reference is made in detail to preferred embodiments of the invention, examples of which are illustrated in the accompanying figures, which show:

Fig. 1 a perspective view of an article treatment machine with a tank assembly,

Fig. 2 another perspective view of the article treatment machine of Fig. 1 without a rear wall and a side wall of the tub,

Fig. 3 a perspective view of the article treatment machine of Fig. 1 without the cabinet and the tub,

Fig. 4 a perspective of a bottom region of Fig. 3,

Fig. 5 another perspective of the bottom region of Fig. 4,

Fig. 6 is a top view of the bottom region of Fig. 4,

Fig. 6 A an exploded view of the sump of Fig. 5,

Fig. 6B a perspective view of the valve arrangement of Fig. 5,

Fig. 7 a perspective of the tank assembly of Fig. 1,

Fig. 8 a front view of another tank assembly, Fig. 9 A an enlarged front view of the air gap of Fig. 7, and

Fig. 9B a schematic view of an air gap in a closed state.

Fig. 1 is a perspective view of an article treatment machine 2 with a tank assembly 42, and Fig. 2 is another perspective view of the article treatment machine of Fig. 1 without a rear wall 16 and a side wall of the tub 10. Exemplarily, the articles treatment machine 2 shown in the Figures is a dishwasher.

The dishwasher 2 comprises a cabinet (not shown) housing a tub 8 for washing articles therein. The tub 8 comprises side walls 10, 12, a top wall 14, a rear wall 16, and a tub bottom 18. The cabinet may further comprise a basement 6 arranged below the tub bottom wall 18.

Dishes, utensils, and other dishware (also referred to herein as 'articles' of the dishwasher 2) may be placed in the tub 8 for cleaning. The dishwasher 2 may also include slidable lower and upper racks or baskets (not shown) for holding the articles to be cleaned. The racks may be movable into and out of the tub 8. The dishwasher may further comprise a door (not shown) that may be pivotably connected with the tub 8 to selectively permit access to the tub 8 when the dishwasher 2 is operating (e.g. when the articles in the dishwasher 2 are washed and/or cleaned).

The dishwasher 2 comprises a sump 20 (as shown in Fig. 3) for collecting washing liquid, typically under the influence of gravity. The washing liquid is used by the dishwasher 2 to clean, wash, and rinse the articles. The sump 20 is arranged below the tub bottom 18, in particular the sump 20 is fluidly connected from below to the tub bottom 18, such that the washing liquid within the tub 8 can flow into the sump 20.

As shown in Fig. 3, the dishwasher 2 may comprise a washing liquid circulation path for circulating the washing liquid during a washing cycle. In particular, the washing liquid collected in the sump 20 may be pumped via a circulation pump 24 through a washing fluid conduit system (not shown). The washing fluid conduit system is preferably connected to one or more spray arms, in particular to a lower, a middle and a top spray arm. The washing fluid conduit system is configured to spray the washing liquid, under pressure, onto the articles contained in the tub 20 during a washing cycle. The dishwasher 2 may comprise a filtration assembly 22 that is connected to the sump 20. The filtration assembly 22 is configured to filter the washing liquid returning to the sump 20 after washing liquid has been deployed in the tub 8 via the water conduit system.

The dishwasher 2 may include a controller (not shown) in communication with one or more of the dishwasher's functional components. E.g. the controller may be in communication with the circulation pump 24 and may be configured to selectively operate the circulation pump 24 to pump washing fluid to at least one of the spray arms of the water conduit system.

As shown in Figs. 3 and 6, the dishwasher may comprise a flow controller 26 which is arranged downstream of the circulation pump 24 (i.e. connected to an outlet of the pump 24) and which is configured for guiding the washing liquid to at least one of the spray arms. In particular, the sump 22 may comprise a plurality of sump outlets 28, 30, 32, 33, 34, wherein the controller is adapted to control the flow controller such that the washing liquid is guided along one or more of the outlets. The sump outlets 28, 30, 32 and the surrounding surface covering the flow controller 26 may also be considered to be part of the flow controller 26 or as a separation wall with outlets between the flow controller and the sump.

The tank assembly 42 for storing heated fresh water and/or for exchanging heat between the washing liquid from the sump 20 is preferably arranged at a side wall of the dishwasher 2. E.g. the tank assembly 42 is arranged at a left side wall of the dishwasher 2 when considering the normal operation position of the dishwasher 2 (as shown in Fig. 1). The tank assembly is basically formed of a shell element 45b which is covered by a cover element 45a (shown in Fig. 1). The shell element 45b in an opened state is shown e.g. in Fig. 7 without the cover which - in the assembled state - is watertight mounted to the shell element. The cover element 45a may have a rib structure formed on the inner or outer side to stabilize against deformation. The shell element has partition elements that provide the lateral walls of tank sections and/or (liquid and/or air) conduits of the shell element.

As shown in Fig. 7, the tank assembly 42 comprises a water tank 44 for storing heated softened fresh water and a tube-in-tube heat exchanger 48 for exchanging heat between softened fresh water and washing liquid from the sump 20. The heat exchanger 48 is preferably arranged next to the water tank 44, more preferably on a lateral (e.g. left) side of the water tank 44. A second passage 50 (in this case an outer tube) of the heat exchanger 48 is preferably formed integrally, i.e. in one piece, with the water tank 44.

The dishwasher 2 comprises a closed loop flow path 64 forming a flow circuit and comprising an inlet at the sump 20, a pump (see below) a first passage 52 (in this case an inner tube) of the heat exchanger 48, and a tub outlet 46. In particular, the inlet at the sump 20 is connected to an inlet 62b of the inner tube 52 (see: Figs. 5-7). The closed loop flow path 64 may further comprise a return channel 66 connecting an outlet 62a of the inner tube 52 to the tub outlet 46. The return channel 66 may be arranged between the heat exchanger 48 and the water tank 44. The return channel 66 is preferably formed integrally, i.e. in one piece, with the water tank 44. The tub outlet 46 is preferably arranged within the water tank 44, wherein in particular at least a portion of the return channel 66 extends through the water tank 44 to the outlet 46 arranged within the water tank 44. The channels of the closed loop flow path 64 comprised in the tank assembly 42 are preferably fluidly separated from an inlet flow path 68 (described below) comprising the water tank 44. In particular, the tub outlet 46 is fluidly separated from the water tank 44. I.e. washing liquid circulated along the closed loop flow path 64 is not guided into the water tank 44. Thus, contamination of the tank by dirty washing liquid from the sump is avoided.

Washing liquid may be circulated along the closed loop flow path 64 via a circulation pump. As shown in the Figures, the circulation pump is the same as the circulation pump 24 for circulating the washing liquid along the water conduit system. Alternatively, an additional circulation pump may be provided for the closed loop flow path 64.

The dishwasher 2 further comprises the inlet flow path 68 having a connection to water mains 78 (see: Fig. 5), a softener assembly 40, the water tank 44, a tank outlet 73 connected to the sump 20, and the outer tube 50 of the heat exchanger 48, wherein the outer tube 50 is arranged downstream of the softener assembly 40 and upstream of the water tank 44.

The residual heat within the washing liquid in the sump 20 can be reused by transferring the heat of the washing liquid guided along the closed loop flow path 64 in the heat exchanger to the softened fresh water guided along the inlet flow path 68 which can then be stored in the water tank 44 until it is used for a further washing cycle. Thus, the overall efficiency of the machine is improved.

A tank valve 114 (see: e.g. Fig. 6) may be provided upstream of the heat exchanger 48 and in particular upstream of the softener assembly 40 for enabling or blocking flow of fresh water into the dishwasher 2. In particular, the connection to water mains 78 is connected to an inlet 60b of the outer tube 50 (see: Figs. 5-7).

As shown in Fig. 6, a flow meter 116 may be provided downstream of the valve 118 and upstream of the heat exchanger 48 and in particular upstream of the softener assembly 40 for providing feedback for the amount of supplied fresh water. Preferably, the flow meter 116 and/or the valve 118 are arranged upstream of the air gap flow conduit 74 described below. The flow meter 116 is preferably integrated in a flow path comprised in the housing 101 of the valve arrangement 100.

A fresh water inlet valve 118 (see: e.g. Fig. 5) may be provided downstream of the water tank 44 and upstream of the sump 20 for enabling or blocking water flow out of the water tank 44. The softener assembly 40 is preferably arranged at least partially below the tank assembly 42.

The inlet flow path 68 may further comprise a flow channel 70 connecting an outlet 60a of the outer tube 50 to an inlet 72 of the water tank 44. The flow channel 70 is preferably arranged next to the water tank 44. Preferably, the flow channel 70 extends from the outlet 60a upwards to the top of the tank assembly 42. The flow channel 70 is preferably formed integrally, i.e. in one piece, with the water tank 44.

Fig. 6A illustrates an exploded view of sump 20 (shown in FIG. 1) and the flow controller 26. Sump 20 includes a disk portion 53 formed within an external side of the sump 20. Flow controller 26 includes a disk 54 having a plurality of outlets, CAM disk 56, switch (not specifically shown), and motor 57. Disk portion 53 of sump is sized and shaped to receive disk 54. CAM disk 56, switch, and motor 57 are configured to rotate disk 54 relative to the first, second, third washing fluid outlets 2, 144, and 146. The flow controller 26 is preferably adapted to control the rotation of the disk 54 such that at least one opening of the disk 54 is aligned to at least one of the sump outlets 28, 30, 32, 33 and 34. I.e. outlets of sump are considered to be "open" when aligned with an opening of the disk and washing fluid can flow, and outlets are considered to be "closed" when not aligned with an opening of the disk and washing fluid can not flow. Depending on the rotation position of the disk, washing liquid can flow through selected outlets of the plurality of outlets 28, 30, 32, 33 and 34, where the selection is made via the rotational position of the disk. Preferably, the first outlet 28 is connected to the first spray arm, the second outlet 30 to the middle spray arm and the third outlet 32 to the top spray arm of the water conduit system. The third or fourth outlets 33, 34 may enable washing fluid to be supplied from sump 20 to a variety of components of the dishwasher 2. For example, third or fourth outlet 33, 34 may provide washing fluid from sump 20 to a component of dishwasher 2 outside of the tub 8. As shown in Fig. 6, the outlet 33 is fluidly connected to the first passage 52 of the heat exchanger. However, generally, in the exemplary embodiment, the controller may signal to the switch and motor 156 to rotate CAM disk 154 at the intervals and times (rotational positions) consistent with the dishwasher cycle and as a result, the disk 152 is suitably moved relative to the sump and outlets. A housing 58 fits around or envelops the disk 54 when the disk 54 is positioned within disk portion 53 of sump 20. In use, the disk 54 is located between the housing 58 and sump 20. CAM disk 56, switch, and motor 57 are located within an internal compartment (not specifically shown) of the housing 58 such that at least the CAM disk is in contact with the disk 54 through the housing 53. The housing 58, the CAM disk 56, the switch, and the motor 57 may have a different configuration. For example, the CAM disk 56, switch, and motor 57 may be immediately adjacent disk 54 rather than separated by a portion of the housing body as shown in Fig. 6A. In particular, such that the housing 58 is below the CAM disk 56, the switch, and the motor 57.

As shown in Fig. 7, the tank assembly 42 may comprise an air gap flow conduit 74 being part of the inlet flow path 68, wherein the flow conduit 74 is arranged downstream of the connection to water mains 78 and upstream of the softener assembly 40. In particular, the connection to water mains 78 is connected to an inlet 75 of the air gap flow conduit 74. The air gap flow conduit 74 comprises an air gap 76 which is arranged at the top of the tank assembly 42, preferably at or above the maximum water level of the water tank 44 (enlarged view of the air gap 76 is shown in Fig. 9A). The air gap flow conduit 74 is preferably arranged next to the water tank 44, preferably on a right side of the water tank 44 when considering the normal operation position of the dishwasher 2. The air gap flow conduit 74 is connected to the air gap, wherein the air gap 76 is connected to the softener assembly 40. In particular, the flow conduit 74 connecting the outlet the air gap 76 to the softener assembly 40 comprises two outlets, wherein one outlet 40a is connected to a salt container of the softener assembly 40, and the other outlet 40b is connected to a resin container of the softener assembly 40.

As shown in Fig. 7, the inlet 73 and outlets 40a, 40b of the air gap flow conduit 74 are arranged at the bottom region of the tank assembly 42. In particular, the air gap flow conduit 74 extends from the inlet 63 at the bottom to the top or upper region of the tank assembly 42 where the air gap 76 is arranged and from there back to the bottom region of the tank assembly to outlets 40a, 40b. Preferably, the air gap 76 is in fluid communication with the water tank 44 such that water leakage at the air gap 76 flows into the water tank 44. When fresh water is supplied with a predetermined pressure along the inlet flow path 68, most of the water will pass through the air gap. However a little leakage of water may be present. This water leakage at the air gap 76 flows automatically due to gravity into the water tank 44.

The fresh water flowing through the air gap flow conduit 74 may be guided either through the outlet 40b connected to the resin container (for softening the fresh water), or, if a regeneration of the resin in the resin container is necessary, through the outlet 40a connected to the salt container and then through the resin container. A valve element such as a two-way valve may be provided upstream of the salt container and preferably downstream of the outlet 40a for enabling or blocking water flow into the salt container.

As shown in Fig. 7, the tank assembly 42 may further comprise an overflow conduit 80 connected to the tub 8, in particular to the tub outlet 46 for guiding fresh water exceeding a maximum water fill level automatically back into the tub 8. The overflow conduit 80 is preferably arranged within the water tank area, preferably arranged within a lower center region of the area of the water tank 44. The inlet of the overflow conduit 80 may extend from a top region of the tank assembly 42, in particular a maximum water level, downwards to the tub outlet 46. The overflow conduit 80 is preferably formed integrally with the water tank 44.

The outlets and inlets of the tank assembly 42, in particular the outlets 40a, 40b, 96b, the inlet 60b, 62b, 96a, 75, and the tank outlet 73 are arranged at the bottom region of the tank. Thus, the assembly of the tank assembly 42 is facilitated since all fluid connections can be connected at the bottom region of the tank assembly 42.

The inlet flow path 68 may further comprise a bypass conduit 111 (flow path connected to first valve outlet 106 as shown in Fig. 6) arranged downstream of the softener assembly 40 and upstream of the heat exchanger 48 for bypassing the heat exchanger 42. Thus, fresh water from water mains can be supplied into the sump 20 while bypassing the heat exchanger 48 and the water tank 44.

The dishwasher 2 may comprise the following different operation modes:

- A passive heat exchange mode in which cold fresh water (e.g. 15°C) from water mains is guided via the inlet flow path 68 into the water tank 44 in which it is stored and heated up over several hours by absorbing ambient heat from the surroundings (to e.g. 23°). I.e. in this case no washing liquid is circulated along the closed loop flow path 64 and thus no heat is exchanged in the heat exchanger 48 between fresh water and washing liquid from the sump 20.

- An active heat exchange mode in which washing liquid and fresh water flow through the heat exchanger 48 and exchange heat with each other. This mode is e.g. used at the end of a pre-wash, wash phase and/or a cold rinse before draining of the washing liquid in the sump 20. Thus, the heat from the washing liquid can be transferred to the fresh water and the heated fresh water can be stored in the water tank 44. The heated fresh water in the water tank 44 may be reused in a next phase of a washing cycle. Therefore, energy needed for the next phase, e.g. a hot rinse, is reduced.

- A quick clean program which can be used, if it is desired to fill up the sump 20 faster and/or if the water stored in the tank is not enough to properly operate the circulation pump. In this case the fresh water supplied via the water mains and being guided through the softener assembly 40 can be directly guided into the sump 20 via the bypass conduit 111 (see: Fig. 6) bypassing the heat exchanger 48 and the water tank 44.

As shown in Figs. 4 and 5, the dishwasher 2 may further comprise a draining path 92 for draining the washing liquid in the sump 20, via a drain pump 90, out of the dishwasher 2. The draining path 92 may comprise a first, second and third draining path section 94a-c. The first draining path section 94a is connected to an inlet at the sump 20 and an inlet 94 of the second draining path section 94b which is arranged at the tank assembly 42. The second draining path section 94b (see: Fig. 7) is preferably comprised in the tank assembly 42. Preferably, the second draining path section 94b is arranged next to the heat exchanger 48, more preferably laterally of the heat exchanger 48 (i.e. at a side of the heat exchanger 48 facing away from the water tank 44). The second draining path section 94b may be integrally formed with the water tank 44. An outlet 96b of the second draining path section 94b is connected to the third draining path section 94c guiding the washing liquid out of the dishwasher 2.

The second draining path section 94b may comprise a siphon or air gap for preventing dirty water to flow back into the dishwasher 2. In particular, the second draining path section 94b may extend from the bottom to the top and from the top to the bottom of the tank assembly forming a siphon. Thus, when the drain pump 90 for draining the washing liquid is stopped, the remaining dirty washing liquid within the second draining path section 94b flows out of the draining path due to gravity. When the draining path 92 has a clog or blockage downstream of the air gap/siphon, no dirty water can flow from the outside of the dishwasher 2 back into the dishwasher 2 via the second draining path section 94b due to the siphon/air gap. Further, the draining path section 94b may comprise a ventilation valve 81 fluidly connecting the draining path section 94b via a flow connection pipe to the tank inlet 72. The flow connection pipe is preferably formed integrally with the tank assembly. The ventilation valve 81 is preferably arranged at the highest vertical point of the draining path section 94b. If washing fluid rises above the ventilation valve 81, the washing fluid is guided via the tank inlet 72 into the tank 44. Thus, the ventilation valve 81 is operating as an overflow channel for the draining path section 94b. As shown in Fig. 6, the valve arrangement 100 may be provided for guiding fresh water from the water tank 44 to the sump 20 and/or from the softener assembly 40 along different flow paths. In particular, the valve arrangement 100 comprises a housing 101 having a first inlet 102 connected to an outlet of the softener assembly 40, a second inlet 104 connected to the tank outlet 73 (see: Figs. 5, 7), a first outlet 106 connected to the sump 20 or tub 8, and a second outlet 108 connected to the outer tube 50 of the heat exchanger 48. Fresh water flowing via the first outlet 106 out of the valve arrangement 100 preferably bypasses the heat exchanger 48.

As shown in Figs. 6 and 6B, the housing 101 comprises at least the following fluid paths: A first fluid path 110a connecting the first inlet 102 to the first outlet 106 such that fresh water from the softener assembly 40 is guided to the sump 20 or tub 8. A second fluid path 110b connecting the first inlet 102 to second outlet 108 such that the fresh water from the softener assembly 40 is guided to the water tank 44 via the heat exchanger 48 (see: Fig. 7). A third fluid path 110c connecting the second inlet 104 to the first outlet 106 such that fresh water from the water tank 44 is guided to the sump 20 or tub 8. The first, second and third fluid paths HOa-c are preferably formed integrally with the housing 101.

The housing may comprise at least one valve and in particular a three-way valve 112 as shown in Figs. 6 and 6B adapted to selectively guide fresh water along the first fluid path 110a or the second fluid path 110b, and the tank valve 114 arranged in the third fluid path 110c and being adapted to block or allow the flow of the fresh water out of the water tank 44 into the sump 20. The three-way valve 112 and the tank valve 114 are preferably integrated in the housing 101, i.e. the valves and the housing 101 form a single unit. The three-way valve 112 may be attached from below to the housing 101. The tank valve 114 may be arranged at least partially within the housing 101.

In case of a three-way valve the following preferably applies: The first fluid path 110a connects a first outlet 113b of the three-way valve 112 to the first outlet 106 of the valve arrangement 100. The second fluid path 110b connects a second outlet 113c of the three-way valve 112 to the second outlet 108. The outlet of the softener assembly 40 is connected to an inlet 113a of the valve 112. Preferably, the housing 101 comprises a fourth fluid path 1 lOd connecting the outlet of the softener assembly 40 to the inlet 113a of the valve 112. The fourth fluid path is preferably formed integrally with the housing 101.

Alternatively to the three-way valve, a first valve and a second valve may be provided, wherein the first valve is arranged in the conduit guiding the fresh water from the first outlet 106 to the sump 20 and the second valve is arranged in the conduit guiding the fresh water from the second outlet 108 to the heat exchanger 48. By controlling the two valves with the controller, the fresh water can either be guided through the heat exchanger 48 and/or directly into the sump 20 bypassing the heat exchanger 48.

The controller may control the valve arrangement 100 such that at least one of the following switching states is applied:

- In a first switching state only the first fluid path 110a guiding fresh water from the softener assembly 40 to the sump 20 is in an open state and the second and third fluid paths 110b, 110c are closed.

- In a second switching state only the second fluid path 110b guiding fresh water from the softener assembly 40 to the water tank 44 via the heat exchanger 48 is in an open state and the first and third fluid paths 110a, 110c are closed.

In a third switching state only the third fluid path 110c guiding fresh water from the water tank 44 to the sump 20 is in an open state and the first and second fluid paths 110a, 110b are closed.

- In a fourth switching state, the second fluid path 110b and the third fluid path 110c are in an open state and the first fluid path 110a is closed.

Alternatively to the valve arrangement 100 shown e.g. in Fig. 6, the valve arrangement 100 may comprise a third outlet (not shown), wherein the third fluid path 110c connects the second inlet 104 to the third outlet which is connected to the sump 20. In this case, the first fluid path 110b preferably connects the first inlet 102 to the first outlet 106 such that the fresh water from the softener assembly 40 is guided to the tub via the tub outlet 46. 1.e. the first and third fluid paths 110a, 110c are fluidly separated from each other and each has its own outlet (compare Fig. 5 in which first and third fluid path 110a, 110c share the same first outlet 106 which is connected to the sump). The first fluid path 110b is connected to the portion 11 la of the bypass conduit which is preferably at least partially comprised in the tank assembly 42 connecting the first outlet 106 to the tub outlet 46. The bypass conduit comprised in the tank assembly 42 is preferably formed integrally with the water tank 44.

Alternatively to the at least one valve (three-way valve) 112 and the tank valve 114, the valve arrangement 100 may comprise a rotatable distributor (not shown) having at least two flow paths, wherein the distributor is rotatable such that in a first switching state one of the flow paths provides a fluid connection from the first inlet 102 to the first outlet 106, in a second switching state one of the flow paths provides a fluid connection from the first inlet 102 to the second outlet 108, in a third switching state one of the flow paths provides a fluid connection from the second inlet 104 to the first outlet 106, and in a fourth switching state one of the flow paths provides a fluid connection from the first inlet 102 to the second outlet 108 and another of the flow paths provides a fluid connection from the second inlet 104 to the first outlet 106. The distributor is preferably connected to a motor for rotating the distributor. The controller may be adapted to control the motor such that the distributor is rotated to specific rotation positions corresponding to the switching states.

Preferably, the housing 101 of the valve arrangement 100 may comprise a bracket which is configured for receiving a fluid connection of the closed loop path connecting the inlet at the sump to the heat exchanger and in particular to the first passage 52 (inner tube) of the heat exchanger. The fluid connection is preferably held in its position by the bracket. The bracket may be formed integrally with the housing 101. Preferably, the bracket is arranged below the housing 101 (i.e. the fluid connection extends below the housing 101).

The tank assembly 42a as shown in Fig. 8 is similar to the tank assembly 42 as shown in Fig. 7. The features described with respect to the Fig. 7 are also applicable to Fig. 8, except the differences which are described in the following. A portion of the bypass conduit 11 la is preferably at least partially comprised in the tank assembly 42 connecting the first outlet 106 to the tub outlet 46. An inlet 11 lb of the portion of the bypass conduit I l la may be provided at the bottom region of the tank assembly 42a. The portion 11 la of the bypass conduit comprised in the tank assembly 42 is preferably formed integrally with the water tank 44. In this case, washing liquid flowing along the closed loop flow path, fresh water from the bypass conduit I l la and fresh water flowing through the overflow conduit 80 share a common outlet, namely tub outlet 46 guiding the washing liquid and/or the fresh water back into the tub 8. Further, the tank assembly 42 comprises an air gap 72a which is described in more detail with respect to the Fig. 9B.

The air gap 72a is a dynamic air gap which comprises a fluid connection to the water tank 44. A porous element 122 is arranged within the connection to the water tank 44. Further, an air gap control element 120 which is e.g. a ball as shown in Fig. 9 is arranged within the air gap 72a adjacent to the porous element 122. When the ball 120 is in a resting position, i.e. no forces are applied to the ball 120, the ball 120 is not in contact with the porous element 122 and a connection to the water tank 44 and the ambient pressure is present (see Fig. 9). This is e.g. the case when the water tank 44 is empty and no fresh water is filled into the tank 44.

When the water tank 44 is filled with fresh water, fresh water is flowing along the air gap flow conduit 74. At the start of the filling process, the fresh water contacts the ball 120 from below such that the ball 120 is moved to the porous element 122 until the ball 120 contacts the porous element 122 such that the connection to the water tank 44 and the connection to the ambient pressure is closed. During the movement of the ball 120 to the porous element 122 (i.e. until the ball 120 contacts the porous element 122) some minor leakage can be released to the water tank 44.

When the filling process is completed, no fresh water is guided along the air gap flow conduit 74 and thus the ball preferably moves back to its resting position (start position) due to gravity. Thus, the connection to the water tank 44 and to the ambient pressure is open again and leakage can be released to the water tank 44.

The dynamic air gap 72a minimizes the water leakage and/or pressure losses at the air gap. Thus all or substantially all fresh water supplied via the connection to the water mains passes the air gap 72a and flows through the second passage of the heat exchanger 48. Therefore, all or substantially all fresh water can be heated before being supplied to the tank. This improves the efficiency of the machine.

Reference Numeral List

2 Articles treatment machine (e.g. dishwasher)

6 basement

8 tub

10, 12 side wall (tub)

14 top wall (tub)

16 rear wall (tub)

18 tub bottom

20 sump

22 filtration assembly

24 circulation pump

26 flow controller

28 first washing fluid outlet

30 second washing fluid outlet

32 third washing fluid outlet

33 fourth washing fluid outlet

34 fifth washing fluid outlet

40 softener assembly

40a outlet to salt container

40b outlet to resin container

42, 42a tank assembly

44 water tank

45a cover element

45b shell element

46 tub outlet of tank

48 heat exchanger (e.g. tube-in-tube heat exchanger)

50 second passage (outer tube of heat exchanger)

52 first passage (inner tube of heat exchanger)

53 disk portion

54 disk

56 CAM disk

57 motor

58 housing of flow controller

59 inlet of flow controller

60a outlet of outer tube

60b inlet of outer tube

62a outlet of inner tube

T1 62b inlet of inner tube

64 closed loop flow path

66 return channel

68 inlet flow path

70 flow channel

72 inlet of tank

72a air gap

73 tank outlet

74 air gap flow conduit

75 air gap flow conduit inlet

76, 76a air gap / air break

78 inflow connection to water mains

80 overflow conduit

81 ventilation valve

90 drain pump

92 draining path

94a-c first / second / third draining path sections

96a, b inlet / outlet of second draining path

100 valve arrangement

101 housing

102 first valve inlet

104 second valve inlet

106 first valve outlet

108 second valve outlet

1 lOa-d first / second / third / fourth fluid path

111 bypass conduit

I l la portion of bypass conduit

111b inlet of portion of bypass conduit

112 valve element (e.g. three-way valve)

113a valve inlet of valve element

113b first valve outlet of valve element

113c second valve outlet of valve element

114 tank valve

116 flow meter

118 fresh water inlet valve

120 air gap control element

122 porous element

Claims

Claims:

1. Articles treatment machine (2), in particular a dishwasher, comprising: a cabinet, a tub (8) for washing articles therein and being arranged in the cabinet, a sump (20) for collecting washing liquid from the tub (8), a circulation pump (24), a softener assembly (40) adapted to softening water flowing therethrough, a tank assembly (42) comprising a water tank (44) for storing fresh water and having a tank outlet (73), a heat exchanger (48), preferably a tube-in-tube heat exchanger, comprising a first passage (52) and a second passage (50) being in heat-exchanging contact with each other, a closed loop flow path (64) forming a flow circuit and comprising an inlet at the sump (20), the first passage (52) through the heat exchanger (48) and an outlet connected to the tub (8) or sump (20), wherein washing liquid is circulated along the closed loop flow path (64) via the circulation pump (24), and an inlet flow path (68) comprising an inflow connection to water mains (78), the softener assembly (40), the second passage (50) through the heat exchanger (48), the water tank (44) and the tank outlet (73) connected to the tub (8) or sump (20), wherein the second passage (50) is arranged downstream of the softener assembly (40) and upstream of the water tank (44).

2. Articles treatment machine of claim 1, wherein the heat exchanger (48) is a tube-in-tube heat exchanger comprising an inner tube (52) forming the first (or the second) passage of the heat exchanger (48) and an outer tube (50) forming the second (or first) passage of the heat exchanger (48), and wherein the inner tube (52) has a smaller cross section is arranged within the outer tube (50) having a larger cross section.

3. Articles treatment machine of claim 1 or 2, wherein the first and/or second passages (52, 50) of the heat exchanger (48) is/are formed integrally with the water tank (44), and/or wherein a or the outer tube (50) of the heat exchanger is formed integrally with the water tank (44).

4. Articles treatment machine of claim 1, 2 or 3, wherein the tank assembly (42) is made of plastic, and/or wherein the heat exchanger (48), in particular the inner tube (52) of the heat exchanger (48), is made of metal such as stainless steel.

5. Articles treatment machine of any of the preceding claims, wherein the tank assembly (42) comprises a flow channel (70) being part of the inlet flow path (68), and wherein the flow channel (70) connects the outlet of the second flow passage (50) of the heat exchanger to an inlet (72) of the water tank, wherein preferably the flow channel (70) is formed integrally with the water tank (44).

6. Articles treatment machine of any of the preceding claims, wherein the treatment machine comprises a bypass conduit (111, I l la) being part of the inlet flow path (68), and wherein the bypass conduit (111, I l la) is arranged downstream of the softener assembly (40) and upstream of the heat exchanger (48) and is connected to an outlet connected to the sump (20) or tub (8).

7. Articles treatment machine of claim 6, wherein a control unit is adapted to selectively guide the fresh water via the outlet of the bypass conduit (111, I l la) into the sump (20) or tub (8) and/or via the heat exchanger (48), in particular via the second passage 50, into the water tank (44).

8. Articles treatment machine of claim 6 or 7, wherein at least a portion of the bypass conduit (11 la) is arranged within the tank assembly (42) and wherein the outlet of the bypass conduit (11 la) is a tub outlet (46) arranged within the water tank (44), and wherein preferably the portion of the bypass conduit (11 la) is formed integrally with the water tank (44).

9. Articles treatment machine of any of the preceding claims, further comprising a flow controller (26) for controlling washing fluid flow in the treatment machine (2), wherein the sump comprises a plurality of washing fluid outlets (28, 30, 32) for supplying washing fluid to a washing fluid conduit system, and at least one extra outlet (33, 34) in fluid communication with the first passage (52), wherein preferably the flow controller (26) includes a positioning device (57) and a disk (54) rotatably arranged in relation to the plurality of washing fluid outlets (28, 30, 32) and the at least one extra outlet (33, 34), and/or wherein preferably the disk (54) comprises a plurality of apertures arranged for selectively closing and opening the plurality of washing fluid outlets (28, 30, 32) and the at least one extra outlet (33, 34) of the sump (20) during rotation of the disk, and/or wherein preferably, when the positioning device (57) aligns at least one of the plurality of apertures of the disk (54) with the at least one extra outlet (33, 34) of the sump (20), washing fluid is permitted to pass from the flow controller (26) via the extra outlet (33, 34) to the first passage (52) of the closed loop path (64), in particular such that the washing fluid conduit system is bypassed.

10. Articles treatment machine of any of the preceding claims, wherein the tank assembly (42) comprises a return channel (66) being part of the closed loop flow path (64), wherein the return channel (66) connects the outlet of the first passage (52) of the heat exchanger to the outlet connected to the tub (8) or sump (20), and wherein preferably the return channel (66) is formed integrally with the water tank (44).

11. Articles treatment machine of any of the preceding claims, wherein the outlet of the closed loop flow path (64) is a tub outlet (46) arranged in proximity to or being at least partially surrounded by the water tank (44) of the tank assembly.

12. Articles treatment machine of any of claims 7 to 11, wherein the outlet of the closed loop flow path (64) is fluidly connected to the tub (8) and is forming a common outlet (46) to the tub (8) with the outlet of the bypass conduit (111, 11 la).

13. Articles treatment machine of any of the preceding claims, wherein the tank assembly (42) comprises a draining path (92) connected to an inlet at the sump (20), wherein the draining path (92) is adapted to drain, via a drain pump (90), washing liquid from the sump (20) out of the treatment machine (2), and wherein preferably a portion of the draining path (92) is formed integrally with the water tank (44).

14. Articles treatment machine of any of the preceding claims, wherein the inlets (60b, 62b, 75, 96a) and outlets (40a, 40b, 73, 96b) of the tank assembly (42) are arranged at a bottom region of the tank assembly (42), and/or wherein the tank assembly (42) and the inlets (60b, 62b, 75, 96a) and outlets (40a, 40b, 73, 96b) of the tank assembly (42) extend in a vertical or substantially vertical plane.

15. Articles treatment machine of any of the preceding claims, wherein the tank assembly (42) comprises an overflow conduit (80) connected to a or the tub outlet (46) and being arranged within the water tank (44) such that fresh water within the water tank (44) exceeding a maximum water fill level is guided back into the tub (8) via the overflow conduit (80), and wherein preferably the overflow conduit (80) is formed integrally with the water tank (44).

16. Articles treatment machine of any of the preceding claims, wherein the tank assembly (42) comprises an air gap flow conduit (74) being part of the inlet flow path (68) and being arranged downstream of the inflow connection to water mains (78) and upstream of the softener assembly (40), wherein the air gap flow conduit (74) comprises an air gap (76).

17. Articles treatment machine of claim 16, wherein the air gap (76) is in fluid communication with the water tank (44) such that water leakage at the air gap (76) flows into the water tank (44).