TWM679529U - Wastewater flow restriction device and drinking water purification equipment - Google Patents

Abstract

This invention relates to a wastewater flow limiting device and a drinking water purification equipment, applicable to the field of drinking water purification equipment. It includes a shell, a cover, and a scale inhibitor. The shell includes an inlet, an outlet, and a flow limiting orifice. The cover is connected to the shell and defines a purification channel between the cover and the shell, allowing wastewater to contact the scale inhibitor. The purification channel connects the inlet and the outlet. The flow limiting orifice connects the outlet and the purification channel, and the flow cross-sectional area of the flow limiting orifice is smaller than the flow cross-sectional area of the purification channel. The scale inhibitor fills the purification channel. This novel device fills the purification channel with a scale inhibitor. As wastewater flows through, the scale inhibitor reacts with calcium, magnesium, and other scale-forming ions in the wastewater, preventing scale formation. This enhances the device's long-term stable operation in complex water quality environments and avoids flow control failures and frequent maintenance issues caused by scaling. The flow-limiting orifice effectively prolongs the contact time between the water flow and the scale inhibitor, allowing for a more complete scale-inhibiting reaction and improving descaling efficiency.

Description

Wastewater flow restriction device and drinking water purification equipment

This invention relates to the field of water purification equipment, and in particular to a wastewater flow limiting device and water purification equipment.

In various water systems, wastewater flow restriction structures are usually installed at the wastewater outlet of the water circuit board. Their core function is to precisely control the flow rate of wastewater discharged from the system. By designing the flow restriction orifice, they balance the water pressure and ensure that the entire water system operates stably according to the preset flow parameters. They are one of the key components for maintaining the normal operation of the water system.

However, most wastewater flow limiting devices on the market currently only have basic flow limiting functions. Since wastewater often contains calcium, magnesium, and other ions that are prone to scaling, these ions tend to deposit on the inner wall of the wastewater flow limiting orifice during long-term use, forming scale, which gradually narrows or even completely blocks the orifice.

Therefore, it is necessary to provide a wastewater flow limiting device and a drinking water purification system to address the problem that scale deposits easily occur at the flow limiting orifice of the wastewater flow limiting device, which affects the stable operation of the water system.

Firstly, this invention provides a wastewater flow limiting device, employing the following technical solution:

A wastewater flow limiting device is used in the wastewater path of a filter element. The wastewater flow limiting device includes at least a shell, a cover, and a scale inhibitor. The shell includes an inlet, an outlet, and a flow limiting orifice, with the inlet and outlet spaced apart. The cover is connected to the shell and defines a purification channel between the cover and the shell for contact between the wastewater and the scale inhibitor. The purification channel is connected between the inlet and the outlet. The flow limiting orifice is connected between the outlet and the purification channel, and the flow cross-sectional area of the flow limiting orifice is smaller than the flow cross-sectional area of the purification channel. The scale inhibitor is filled in the purification channel.

In one embodiment, the wastewater flow limiting device further includes a barrier having a plurality of spaced flow gaps that connect the flow limiting orifice and the purification channel, and the width of the flow gaps is smaller than the diameter of the scale inhibitor.

In one embodiment, the wastewater flow limiting device further includes at least two barrier members, which are fixed to the inner wall of the shell and spaced apart along the outer periphery of the flow limiting hole. A flow gap is formed between adjacent barrier members for water supply, and the width of the flow gap is smaller than the diameter of the scale inhibitor.

In one embodiment, the wastewater flow limiting device includes a partition disposed within the housing, the partition being fixed to the inner wall of the housing so that the purification channel extends in a "C" shape.

In one embodiment, the wastewater flow limiting device includes multiple partitions disposed within the shell, with two adjacent partitions respectively fixed to the two opposing inner walls of the shell and the cover, so that the purification flow channel extends in a serpentine shape.

In one embodiment, the wastewater flow limiting device further includes a check valve installed in the housing, the check valve being located between the inlet and the scale inhibitor, for controlling the unidirectional flow of wastewater from the inlet to the outlet.

In one embodiment, the wastewater flow limiting device further includes a plurality of connectors disposed between the shell and the cover, all of which are spaced apart circumferentially along the shell, and the connectors are used to fix the cover to the shell.

In one embodiment, the connector includes a locking portion, a first connecting portion, and a second connecting portion. The first connecting portion is fixed to the cover, and the second connecting portion is fixed to the shell. Along the assembly direction of the cover and the shell, the locking portion passes through and connects the first connecting portion and the second connecting portion.

In one embodiment, the wastewater flow limiting device further includes a seal installed between the housing and the cover, such that the cover is sealed to the housing.

Secondly, this invention provides a water purification device, which adopts the following technical solution:

A water purification device includes a water circuit board and the aforementioned wastewater flow limiting device. The water circuit board has a wastewater inlet and a wastewater outlet arranged at intervals. The wastewater flow limiting device is installed on the water circuit board and connected between the wastewater inlet and the wastewater outlet of the water circuit board.

The aforementioned wastewater flow restriction device, by filling the purification channel with scale inhibitor, allows the scale inhibitor to react with calcium, magnesium, and other easily scale-forming ions in the wastewater as it flows through, preventing scale formation. This enhances the device's long-term stable operation in complex water quality environments and avoids flow control failures and frequent maintenance issues caused by scaling. Furthermore, the flow restriction orifice, while balancing water pressure, effectively prolongs the contact time between the water flow and the scale inhibitor, resulting in a more complete scale inhibition reaction and improved descaling efficiency.

To make the above-mentioned objects, features, and advantages of this invention more apparent, the specific embodiments of this invention are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this invention. However, this invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of this invention. Therefore, this invention is not limited to the specific embodiments disclosed below.

In the description of this invention, it should be understood that if terms such as "center", "longitudinal", "horizontal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this novel invention, the term "multiple" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

In this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can be a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

In this invention, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact, or that they are indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "under," and "below" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

If an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element present. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only and do not represent the only embodiments.

The embodiments of this invention will be further described in detail below with reference to Figures 1 to 6.

Referring to Figures 1 and 6, Figure 1 shows a schematic diagram of the assembly of the wastewater flow limiting device in one embodiment of the present invention. Figure 6 shows a drinking water purification device A provided in one embodiment of the present invention, which includes at least a water circuit board C and a wastewater flow limiting device B installed on the water circuit board C. The water circuit board C includes a wastewater inlet and a wastewater outlet arranged at intervals, and the wastewater flow limiting device B is installed on the water circuit board C and connected between the wastewater inlet and the wastewater outlet of the water circuit board C.

In the actual water production process, wastewater enters from the wastewater inlet of water circuit board C and is discharged from the wastewater outlet of water circuit board C after flowing through the wastewater flow limiting device B. The wastewater flow limiting device B is used to regulate the flow rate of wastewater discharged by the system in order to maintain the normal operation of the water circuit system.

Furthermore, the wastewater flow limiting device B is equipped with a fixing component 10, which has a threaded hole. After the wastewater flow limiting device B is installed on the water circuit board C and the water circuit connection is completed, it is tightly locked to the water circuit board C by screws or bolts passing through the threaded hole on the fixing component 10, thereby achieving a stable connection between the wastewater flow limiting device B and the water circuit board C, making the water circuit structure more stable.

In this new embodiment, only one implementation method is shown as an example. It is understood that in some other embodiments, the wastewater flow limiting device B can also achieve a stable connection with the water circuit board C by means of other structures, which will not be described in detail here.

Referring to Figures 2 and 3, Figure 2 shows a three-dimensional structural schematic diagram of the wastewater flow limiting device B in an embodiment of the present invention, and Figure 3 shows a cross-sectional schematic diagram of the wastewater flow limiting device B in an embodiment of the present invention.

In some embodiments, the wastewater flow limiting device B includes a housing 1 and a cover 2 installed on the housing 1. The cover 2 and the housing 1 can be fixedly connected by spin welding or bonding. In other embodiments, the cover 2 and the housing 1 can also be detachably connected.

In this new embodiment, the wastewater flow limiting device B includes multiple connectors 7 disposed between the cover 2 and the shell 1. All connectors 7 are distributed at intervals along the circumference of the shell 1, preferably evenly distributed along the circumference of the shell 1, thereby stably fixing the cover 2 to the shell 1.

Specifically, the connector 7 includes a locking part 71, a first connecting part 72, and a second connecting part 73. The first connecting part 72 is a block-shaped connecting structure fixed to the cover 2, and the second connecting part 73 is also a block-shaped connecting structure fixed to the shell 1. The locking part 71 can be a screw or bolt structure. Along the assembly direction of the cover 2 and the shell 1, the locking part 71 passes through and connects between the first connecting part 72 and the second connecting part 73, thereby locking the cover 2 to the shell 1 to complete a stable and detachable connection between the cover 2 and the shell 1.

Furthermore, in some embodiments, the wastewater flow limiting device B also includes a seal 8, which may be a sealing ring made of a flexible material such as rubber or silicone. A groove (not shown) is formed at the joint between the shell 1 and the cover 2 for the installation of the seal 8. After the cover 2 is installed into the shell 1, the seal 8 is pressed against the cover 2 and the shell 1 to improve the sealing performance of the connection between the cover 2 and the shell 1.

Referring to Figure 3, the housing 1 includes an inlet connector 11 and an outlet connector 12 spaced apart. Both the inlet connector 11 and the outlet connector 12 are inserted into the water circuit board C. This wastewater flow limiting device B can be used with filter cartridges of different sizes, has a wide range of applications, and is easy to replace.

Specifically, the inlet connector 11 has an inlet 111 for connecting to the wastewater inlet of the water circuit board C, and the outlet connector 12 has an outlet 121 for connecting to the wastewater outlet of the water circuit board C. In this embodiment of the invention, in order to improve the sealing performance after the wastewater flow limiting device B and the water circuit board C are inserted, sealing rings can be provided at the insertion points of the inlet connector 11 and the outlet connector 12 with the water circuit board C to achieve a seal.

It is understood that the connection between the wastewater flow limiting device B and the water circuit board C is not limited to a plug-in connection. In some other embodiments, the wastewater flow limiting device B and the water circuit board C may also be connected by a threaded lock or other forms of sealed connection. This invention does not impose any restrictions on this.

Referring again to Figure 3, the cover 2 is installed at the end of the shell 1, and together with the shell 1, defines the purification channel 5 for wastewater to come into contact with the scale inhibitor 9. The purification channel 5 is connected between the inlet 111 and the outlet 121. During the water purification process of the drinking water equipment, the purification channel 5 is filled with a sufficient amount of scale inhibitor 9. When the wastewater flows through the purification channel 5, it can fully react with the scale inhibitor 9, thereby inhibiting the formation of scale.

In this novel embodiment, the purification channel 5 is configured in a tortuous shape. The scale inhibitor 9 is a granular or blocky chemical agent that can effectively react with calcium, magnesium, and other easily scale-forming ions in wastewater to inhibit scale formation. Specifically, it can be silicon phosphate crystals, SP3, etc. The scale inhibitor 9 can form soluble complexes with calcium and magnesium ions in water, thereby effectively preventing calcium and magnesium ions from forming scale in the wastewater solenoid valve and wastewater pipe, thus ensuring that the wastewater pipe will not be blocked, and making the water purifier have a longer service life.

In this new invention, scale inhibitor 9 is filled into the purification channel 5. When wastewater flows through, scale inhibitor 9 can react with calcium, magnesium and other scale-forming ions in the wastewater to prevent scale formation. This fundamentally solves the problem of scale formation in the flow restriction orifice 6, effectively improves the long-term stable operation of the device in complex water quality environments, and avoids flow control failure and frequent maintenance problems caused by scale formation.

Furthermore, due to the tortuous structure of the purification channel 5, on the one hand, the contact area and contact time between the water flow and the scale inhibitor 9 are increased, making the scale inhibition reaction more complete and improving the scale inhibition efficiency; on the other hand, the tortuous channel design disperses the impact force of the water flow on the inner wall of the device, reducing the scouring and wear of the water flow on the flow limiting hole 6 and the overall structure of the device. Compared with the traditional straight-cylinder channel, it greatly extends the service life of the device and reduces the replacement cost caused by equipment damage, meeting the requirements of energy saving, emission reduction and sustainable use.

Referring to Figures 3, 4, and 5, Figure 4 shows a cross-sectional view of the wastewater flow limiting device B in one embodiment of the present invention from another angle, and Figure 5 shows a schematic diagram of the water flow inside the wastewater flow limiting device B in one embodiment of the present invention. The wastewater flow limiting device B includes a partition 3 disposed within the shell 1. The partition 3 is specifically a plate-shaped blocking component. The partition 3 is located within the purification channel 5 and fixed to the inner wall of the shell 1, so that the purification channel 5 extends in a "C" shape, thereby lengthening the flow path of wastewater within the wastewater flow limiting device B, making the reaction between wastewater and descaling agent more complete, and improving descaling efficiency.

In some other embodiments, the wastewater flow limiting device B includes multiple partitions 3 disposed within the housing 1, each partition 3 also being configured as a plate-shaped blocking component. Two adjacent partitions 3 are respectively fixed to the two opposing inner walls of the housing 1 and the cover 2, so that the purification channel 5 extends in a serpentine manner, thereby further extending the flow distance of wastewater within the wastewater flow limiting device B, and thus further increasing the contact time between wastewater and descaling agent.

In some embodiments, the separator 3 is integrally formed on the inner wall of the shell 1, and the outer wall of the separator 3, the cover 2, and the inner wall of the shell 1 define a tortuous purification channel 5. In other embodiments, the separator 3 and the shell 1 can also adopt a separate structure, with the separator 3 fixed to the inner wall of the shell 1 by bonding or welding, which can also cooperate with the cover 2 and the shell 1 to define a tortuous purification channel.

Referring again to Figure 5, in some embodiments, the wastewater flow limiting device B also includes a check valve 4 installed in the housing 1. Specifically, the check valve 4 is installed between the inlet 111 and the scale inhibitor 9, and is sealed to the housing 1. It is used to control the wastewater to always flow into the inlet 111 of the inlet connector 11 and out of the outlet 121 of the outlet connector 12, maintaining a stable unidirectional flow of wastewater, thereby preventing the scale inhibitor 9 in the purification channel 5 from flowing back into the water system and causing pollution to the purified water.

Referring to Figures 3 and 5, in some embodiments, the housing 1 further includes a flow-limiting orifice 6, which connects the outlet 121 and the purification channel 5. The flow-limiting orifice 6 has a flow cross-sectional area smaller than that of the purification channel 5, and the inner diameter of the flow-limiting orifice 6 is smaller than that of the scale inhibitor 9, in order to limit the flow of wastewater flowing out of the wastewater flow-limiting device B.

Referring to Figure 4, in some embodiments, the wastewater flow limiting device B further includes a barrier 13 fixed to the inner wall of the housing 1. The barrier 13 has a plurality of flow gaps 14 through which water flows. All the flow gaps 14 are spaced apart on the surface of the barrier 13 and are used to connect the aforementioned flow limiting orifice 6 to the purification channel 5. In this new embodiment, the width of the flow gaps 14 is set to be smaller than the diameter of the scale inhibitor 9 to achieve the function of blocking the scale inhibitor 9 particles and preventing the scale inhibitor 9 from clogging the flow limiting orifice 6.

Specifically, the barrier 13 can be constructed in a C-shape or other structures. When the scale inhibitor 9 blocks the opening on the top surface of the barrier 13, the side opening of the barrier 13 can still allow water to flow smoothly, thereby effectively solving the problem that water cannot pass through after the scale inhibitor 9 blocks the flow restrictor 6.

In some other embodiments, the wastewater flow restrictor B also includes at least two baffles 13 fixed to the inner wall of the housing 1. All baffles 13 are spaced along the outer periphery of the flow restrictor 6, preferably evenly distributed along the circumference of the flow restrictor 6. A flow gap 14 is formed between two adjacent baffles 13 for water supply to pass through. Water purified by the scale inhibitor 9 can pass through this gap smoothly into the flow restrictor 6 and be discharged from the outlet 121. Specifically, the gap size of the flow gap 14 is set to be smaller than the diameter of the scale inhibitor 9, so as to ensure that the scale inhibitor 9 will not enter the area enclosed by the barrier 13 during the water purification process, and to prevent the scale inhibitor 9 particles from clogging the flow limiting hole 6, thereby improving the operational reliability of the wastewater flow limiting device B.

In other embodiments, the barrier 13 may be integrally formed on the inner wall of the housing 1 to simplify the manufacturing process.

Referring to Figures 1 to 3, in this embodiment of the novel, the wastewater flow limiting device B is inserted into the water circuit board C. Wastewater enters the purification channel 5 through the inlet 111. After passing through the check valve 4, it comes into contact with the scale inhibitor 9 and begins to dissolve, thus inhibiting scale formation in the wastewater. As the water volume increases, it overflows the intermediate partition 3 and overflows from the top. During this process, it continues to contact the scale inhibitor 9 and inhibit scale formation in the wastewater. Finally, the wastewater passes through the flow limiting hole 6 in the shell 1 and is discharged through the outlet 121.

In this new embodiment, the wastewater flow limiting device B, through the scale-inhibiting design within the purification flow channel 5, ensures that the flow limiting orifice 6 will not be blocked by scale, maintaining a stable orifice diameter. This guarantees precise control of the wastewater flow rate, enabling the entire water system to operate stably according to the preset flow parameters. It avoids damage to other water system components caused by flow fluctuations, improves the overall operational stability and reliability of the water system, and effectively solves the problem of flow control accuracy being affected by scale in the prior art.

The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The embodiments described above are merely examples illustrating several implementations of this invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this invention, and these modifications and improvements all fall within the scope of protection of this invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

1: Shell 11: Inlet 111: Inlet 12: Outlet 121: Outlet 2: Cover 3: Divider 4: Check Valve 5: Purification Flow Channel 6: Flow Restriction Orifice 7: Connector 71: Locking Part 72: First Connector 73: Second Connector 8: Seal 9: Scale Inhibitor 10: Fixing Part 13: Barrier Part 14: Flow Gap A: Drinking Water Purification Equipment B: Wastewater Flow Restriction Device C: Water Circuit Board

Figure 1 is a schematic diagram of the wastewater flow limiting device assembly in one embodiment of the present invention. Figure 2 is a three-dimensional schematic diagram of the wastewater flow limiting device in one embodiment of the present invention. Figure 3 is a cross-sectional schematic diagram of the wastewater flow limiting device in one embodiment of the present invention. Figure 4 is a cross-sectional schematic diagram of the wastewater flow limiting device in one embodiment of the present invention from another angle. Figure 5 is a schematic diagram of the water flow inside the wastewater flow limiting device in one embodiment of the present invention. Figure 6 is a schematic diagram of the wastewater flow limiting device installed in the drinking water purification equipment of the present invention.

1: Shell

11: Water Inlet Connector

111: Water Inlet

12: Water outlet connector

121: Water outlet

2: Cover Body

3: Separator

4: Check valve

5: Purified flow channel

6: Flow limiting orifice

72: First Connecting Section

73: Second Connecting Section

8: Seals

9: Scale inhibitors

13: Barrier component

14: Flow gap

Claims (10)

A wastewater flow limiting device for the wastewater path of a filter element, characterized in that the wastewater flow limiting device includes at least: a shell (1), including an inlet (111), an outlet (121) and a flow limiting hole (6), wherein the inlet (111) and the outlet (121) are spaced apart; A cover (2) is connected to the shell (1) and defines a purification channel (5) between the cover (1) and the shell (1), the purification channel (5) being connected between the inlet (111) and the outlet (121); a flow restrictor (6) is connected between the outlet (121) and the purification channel (5), and the flow cross-sectional area of the flow restrictor (6) is smaller than the flow cross-sectional area of the purification channel (5); and a scale inhibitor (9) is filled in the purification channel (5). According to claim 1, the wastewater flow limiting device further includes a barrier (13), the barrier (13) having a plurality of spaced flow gaps (14) that can connect the flow limiting orifice (6) and the purification channel (5), and the gap width of the flow gaps (14) is smaller than the diameter of the scale inhibitor (9). According to claim 1, the wastewater flow limiting device further includes at least two baffles (13), which are fixed to the inner wall of the shell (1) and spaced along the outer periphery of the flow limiting hole (6). A flow gap (14) is formed between adjacent baffles (13) for water to flow through, and the width of the flow gap (14) is smaller than the diameter of the scale inhibitor (9). According to claim 1, the wastewater flow limiting device includes a partition (3) disposed within the shell (1), the partition (3) being fixed to the inner wall of the shell (1) so that the purification channel (5) extends in a “C” shape. According to claim 1, the wastewater flow limiting device includes multiple partitions (3) disposed in the shell (1), and two adjacent partitions (3) are respectively fixed to the two opposing inner walls of the shell (1) and the cover (2) so that the purification channel (5) extends in a serpentine shape. The wastewater flow limiting device according to any one of claims 1 to 5, wherein the wastewater flow limiting device further includes a check valve (4) installed in the housing (1), the check valve (4) being located between the inlet (111) and the scale inhibitor (9) for controlling the unidirectional flow of wastewater from the inlet (111) to the outlet (121). The wastewater flow limiting device according to any one of claims 1 to 5, wherein the wastewater flow limiting device further includes a plurality of connectors (7) disposed between the shell (1) and the cover (2), all of the plurality of connectors (7) being distributed circumferentially along the shell (1), the plurality of connectors (7) being used to fix the cover (2) to the shell (1). According to the wastewater flow limiting device of claim 7, the plurality of connectors (7) include a locking part (71), a first connecting part (72) and a second connecting part (73), the first connecting part (72) is fixed to the cover (2), the second connecting part (73) is fixed to the shell (1), and the locking part (71) passes through and connects the first connecting part (72) and the second connecting part (73) along the assembly direction of the cover (2) and the shell (1). The wastewater flow limiting device according to any one of claims 1 to 5, wherein the wastewater flow limiting device further includes a seal (8) installed between the housing (1) and the cover (2) such that the cover (2) is sealed to the housing (1). A beverage purification device, characterized in that the beverage purification device (A) includes at least: a water circuit board (C) disposed in the beverage purification device (A) and having a wastewater inlet and a wastewater outlet disposed at intervals; and a wastewater flow limiting device (B) as described in any one of claims 1 to 9, installed in the water circuit board (C) and connected between the wastewater inlet and the wastewater outlet of the water circuit board (C).