Humidifier for fuel cells with heatable outlet for condensed water

Abstract

The invention relates to a humidifier (1) for humidifying a dry first gas flow (4) by means of a moist second gas flow (5), in particular for a fuel cell system, - wherein a condensate trough (14) for collecting condensate is formed in a housing (2), - wherein the housing (2) has a heating channel (15) in the region of the condensate trough (14), through which heating channel a heating agent (16) can flow, - wherein the housing (2) has a condensate discharge opening (19) within the condensate trough (14). Improved de-icing can be achieved if - the condensate discharge opening (19) has an internal thread (20), - the humidifier (1) has a hollow screw (21) which is made of metal, is led out of the housing (2), contains a screw channel (22) and has an external thread (23) by means of which the hollow screw (21) is screwed into the condensate discharge opening (19), - the humidifier (1) has a connecting element (28) which is fastened, by means of the hollow screw (21), to the cover (12), said cover containing a condensate channel (30) which fluidically connects the screw channel (22) to a condensate outlet (29) for discharging condensate.

Description

[0001] October 6, 2025

[0002] 1

[0003] humidifier

[0004] The present invention relates to a humidifier for humidifying a dry first gas stream by means of a moist second gas stream according to the preamble of claim 1.

[0005] Such a humidifier can be used, in particular, in a fuel cell system to humidify dry cathode supply air using moist cathode exhaust air. However, any other application for such a humidifier is also conceivable. For example, in building air conditioning systems, moist building exhaust air can be used to humidify dry building supply air. The same applies to climate-controlled rooms and climate chambers where constant humidity with air exchange is required. In this context, moisture refers to water, which can be liquid, gaseous, droplet-shaped, or vaporous – i.e., gaseous and droplet-shaped.

[0006] A typical humidifier is, for example, made from the

[0007] DE 10 2021 204 250 A1 is known and has a housing with a condensate trough for collecting condensate accumulating in the housing, wherein the housing has a heating channel in the area of ​​the condensate trough through which a heating medium can flow, and wherein the housing has a condensate drain opening within the condensate trough. A condensate outlet for discharging the condensate from the housing is located on the outside of the housing and is fluidically connected to the condensate drain opening. In the known humidifier, the condensate outlet is located directly on the housing. 06.10.2025

[0008] Two outlet nozzles are formed, into which the condensate outlet opening transitions directly. Condensate drainage is achieved using the condensate drain opening and the condensate outlet.

[0009] Furthermore, the housing of the known humidifier has a membrane receiving chamber into which at least one membrane insert is placed. This membrane insert is fluidically separated from the first and second gas streams and transfers moisture from the second gas stream to the first as the fluid flows through it. The housing has an opening through which the respective membrane insert can be inserted into the membrane receiving chamber. The housing is also equipped with a lid that closes the opening and forms a condensate basin on the inside of the lid facing the membrane receiving chamber. This basin collects condensate accumulating in the membrane receiving chamber. The lid also has a heating channel in the area of ​​the condensate basin. This channel is permeable to the heating medium and has a heating medium inlet for supplying the heating medium and a heating medium outlet for discharging it.Furthermore, the lid has a condensate drain opening on the inside of the condensate basin, through which the condensate accumulating in the condensate basin can be drained from the housing and fed to the condensate outlet located on the outside of the housing.

[0010] With a humidifier that has a condensate drain, it can be advantageous to control the condensate drainage, for example, to prevent the intake of ambient air from the humidifier's surroundings during operation of a system equipped with the humidifier. If the system operating with the humidifier is switched off, the condensate drain may be blocked, meaning that condensate may still be present in the condensate tray. In unfavorable circumstances, 06.10.2025

[0011] At ambient temperatures of 3°C, the condensate can freeze and block the condensate drain. When the system is subsequently put into operation, heating fluid is pumped through the humidifier's heating channel, which liquefies the condensate within the condensate tray. However, it has been observed that condensate located outside the condensate tray in the drainage system does not thaw, or does not thaw quickly enough, even when the condensate tray is heated. As a result, the drainage system remains blocked by frozen condensate. Depending on the ambient temperature, it can therefore take a relatively long time for the condensate drain to thaw completely and function again. By then, a considerable amount of new condensate may have accumulated, reducing the humidifier's efficiency.

[0012] The present invention addresses the problem of providing an improved embodiment for a humidifier of the type described above, which is characterized in particular by improved defrosting of the condensate drain.

[0013] This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments are the subject matter of the dependent claims.

[0014] The invention is based on the general concept of using a heat-conducting hollow screw, preferably made of metal, in the condensate drain, which connects directly to the condensate drain opening. Metal components are characterized by a significantly higher thermal conductivity compared to plastic components, which means that when the condensate in the condensate tray heats up, heat can be transferred via the hollow screw into the condensate drain. In this way, 06.10.2025

[0015] 4. The condensate drainage system will break free more quickly overall.

[0016] Specifically, the invention proposes that the condensate drain opening has an internal thread and that the humidifier includes a heat-conducting hollow screw, preferably made of metal, extending from the housing. This hollow screw contains a screw channel and has an external thread with which it is screwed into the condensate drain opening. The hollow screw penetrates the housing. Optionally, the humidifier can also include a connecting element that is attached to the housing by the hollow screw. This connecting element has the condensate outlet and contains a condensate channel that fluidically connects the screw channel to the condensate outlet. The hollow screw thus fulfills a dual function: it secures the connecting element to the lid while simultaneously transferring heat from the condensate basin to the connecting element, which facilitates the defrosting of the condensate channel.

[0017] According to an advantageous embodiment, the housing can have a membrane receiving chamber. The humidifier can then have at least one membrane insert placed in the membrane receiving chamber, through which the first and second gas streams can flow in a fluidically separated manner, and which transfers moisture from the second gas stream to the first gas stream as the fluid flows through it. The housing can have a housing opening through which the respective membrane insert can be inserted into the membrane receiving chamber. The housing can also have a lid that closes the housing opening. A particularly advantageous configuration is one in which the lid forms a condensate basin on its inner surface facing the membrane receiving chamber for collecting condensate accumulating in the membrane receiving chamber, with the heating channel located in the area of ​​the condensate basin.

[0018] The lid has a recess formed in the 5-well, with the heating channel having a heating medium inlet formed in the lid for supplying the heating medium and a heating medium outlet formed in the lid for discharging the heating medium. The condensate drain opening is formed on the inside of the lid within the condensate recess. In this configuration, the hollow screw penetrates the lid such that an inlet end of the screw channel is open at an inner screw end facing the condensate recess, while an outlet end of the screw channel is open outside the lid at an outer screw end facing away from the condensate recess. In this configuration, the connecting element is attached to the lid by the hollow screw, with the condensate channel of the connecting element fluidically connecting the outlet end of the screw channel of the hollow screw to the condensate outlet.

[0019] According to an advantageous embodiment, the humidifier can have a control valve for controlling the fluidic connection between the screw channel and the condensate channel. The control valve allows the discharge of condensate from the condensate basin to be controlled, for example, as needed and / or in such a way as to prevent air from being drawn in from the humidifier's surroundings. Advantageously, the control valve can be attached to the connecting element and interact with the hollow screw to control the outlet of the screw channel. This gives the connecting element an additional function and also simplifies the control of the fluidic connection between the screw channel and the condensate channel by the control valve.

[0020] According to an advantageous embodiment, the control valve can have an adjustable valve element for controlling the outlet end of the screw channel, 06.10.2025

[0021] 6 which is adjustable on the hollow screw. This gives the hollow screw an additional function, as it interacts with the valve element to control the condensate drainage.

[0022] A particularly advantageous configuration is one in which the hollow screw has a screw head that presses the connecting element against the cover and features an axially open annular groove that encloses a central area of ​​the screw head and into which the valve element engages. The screw channel can expediently extend into the screw head, so that the outlet end of the screw channel is open in the central area. This results in a particularly simple and effective operation for the control valve.

[0023] According to another advantageous embodiment, the cover can have a plastic cover plate attached to the housing, which includes a heating section of the heating channel open towards the membrane receiving chamber, the heating medium inlet, and the heating medium outlet. The cover can also be equipped with a metal trough plate attached to the inside of the cover plate, which forms the condensate trough and closes the open heating section. The condensate drain opening with the internal thread is formed on the trough plate, so that the internal thread is also made of metal. This ensures that the metal hollow screw is in direct contact with the metal trough plate, allowing the heat supplied by the heating medium to pass directly from the trough plate into the hollow screw, thus promoting the heating of the condensate outside the condensate trough.

[0024] In principle, the connecting element can be a metal component. However, a preferred embodiment comprises a plastic support body and a channel body forming the condensate channel. (06.10.2025)

[0025] 7

[0026] The metal component is enclosed by the support body. The connecting element and the hollow screw are designed so that the hollow screw is directly supported by the channel body and presses the support body against the cover via the channel body. This creates direct contact between the metallic hollow screw and the metallic channel body, enabling direct heat transfer from the hollow screw to the channel body, which promotes the heating of the condensate contained in the condensate channel. In particular, a combination of the two aforementioned embodiments can now promote heat transfer from the condensate basin to the condensate outlet. The heating medium heats the metallic basin plate, which is in direct contact with the metallic hollow screw, which in turn is also in direct contact with the metallic channel body.Through heat conduction, the heat is transferred from the trough plate via the hollow screw to the channel body, thus allowing the condensate to be heated from the condensate drain opening to the condensate outlet.

[0027] Suitable metals for the hollow screw and especially for the recess plate and the channel body are light metals or light metal alloys, for example based on aluminum, which are characterized by particularly high thermal conductivity.

[0028] The hollow screw can be used to pass through the cover plate in a through-hole, pressing the recessed plate against the cover plate from the inside and pressing the support body against the cover plate from the outside. This allows the hollow screw to also secure the recessed plate to the cover plate.

[0029] In another embodiment, the channel body can have a sleeve section 06.10.2025

[0030] 8. The channel body has a section on which the hollow screw is supported and which is fluidically connected to the outlet end of the screw channel. Furthermore, the channel body can have a pipe section that fluidly connects the sleeve section to the condensate outlet, which can be formed, in particular, on the support body. The sleeve section facilitates the interaction between the hollow screw and the control valve. The pipe section carries the condensate away from the sleeve section, so that a position for the condensate outlet away from the control valve is possible, which facilitates the drainage of the condensate.

[0031] According to an advantageous embodiment, the pipe section can connect tangentially to the sleeve section, for example, on a side of the sleeve section facing away from the cover. This allows for an increased distance between the pipe section and the membrane receiving chamber, which can be used, for example, to design cooling fins and / or stiffening ribs on an outer surface of the cover. Additionally or alternatively, the sleeve section can coaxially enclose the hollow screw, forming an annular space. This annular space is fluidically connected to the interior of the pipe section. Condensate flows from the outlet end of the screw channel into the annular space and from there via the pipe section to the condensate outlet.

[0032] An advantageous embodiment includes a humidifier with a condensate filter element located on the inside of the lid, separating the condensate basin from the membrane receiving chamber. The condensate filter element can conveniently be attached to the basin plate mentioned above. This filter element retains particulate impurities that may be present in the condensate, allowing filtered condensate to enter the condensate basin and be drained away. 06.10.2025

[0033] 9

[0034] Advantageously, the condensate filter element can be flat and, in particular, circular in shape, recessed into the inside of the lid, and can also feature a particle filter material permeable to condensate. This results in a particularly compact design for the condensate tray equipped with the condensate filter element.

[0035] Alternatively, the condensate filter element can be conical and incorporate a particle filter material permeable to condensate. The conical condensate filter element can also have a tip projecting into the membrane receiving chamber and a circumferential rim, which is conveniently recessed into the inside of the lid. Using such a conical condensate filter element provides a larger surface area for the particle filter material with the same diameter than, for example, using a flat, plate-shaped condensate filter element.

[0036] In an alternative embodiment, the condensate filter element can be cylindrical and have an end plate projecting into the membrane receiving chamber, a cylinder wall connecting the end plate to the cover, and a particle filter material permeable to condensate. The particle filter material can be formed on the end plate and / or on the cylinder wall.

[0037] In another embodiment, the hollow screw can be sealed with a first radial seal against the cover and with a second radial seal against the connecting element. This results in a particularly reliable seal of the condensate tray against the humidifier's surroundings. Additionally or alternatively, the connecting element can be sealed with an axial seal against the cover. Particularly in combination with the two radial seals, this results in a two-stage and therefore- 06.10.2025

[0038] 10 with particularly effective sealing of the condensate basin from the humidifier's surroundings. The hollow screw necessarily has a screw axis that defines a longitudinal axis for the hollow screw. The respective radial seal then rests radially to the longitudinal axis of the hollow screw against the sealing partners, while the axial seal rests parallel to the longitudinal axis of the hollow screw against the sealing partners.

[0039] In another advantageous embodiment, the condensate trough can be cylindrical and define a cylinder axis. The condensate drain opening, together with its internal thread, defines a longitudinal thread axis. Advantageously, the condensate drain opening is arranged on the condensate trough such that the longitudinal thread axis extends in a plane perpendicular to the cylinder axis. Thus, the condensate drain opening is oriented transversely to the cylinder axis. In particular, the longitudinal thread axis can extend radially to the cylinder axis, i.e., perpendicular to the cylinder axis. The hollow screw extends coaxially to the longitudinal thread axis, so that the hollow screw also extends transversely and, in particular, radially to the cylinder axis. The connecting element can now be configured such that the condensate channel defines a longitudinal channel axis that extends perpendicular to both the cylinder axis and the longitudinal thread axis.This creates a deflection of the condensate, enabling a compact design for the condensate drainage on the outside of the lid.

[0040] An advantageous embodiment includes a heating channel with a straight inlet section connecting the heating medium inlet to the heating section and a straight outlet section connecting the heating section to the heating medium outlet. The inlet and outlet sections can extend parallel to each other and parallel to the longitudinal direction of the thread. Thus, the inlet and outlet sections each extend transversely. 06.10.2025

[0041] 11 to the cylinder axis. The hollow screw can now be conveniently connected to the condensate tray between the inlet and outlet sections. This results in a particularly compact design on the cover.

[0042] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0043] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention as defined by the claims. Components of a higher-level unit, such as a device, apparatus, or arrangement, mentioned above and those to be mentioned below, which are designated separately, can form separate parts or components of this unit or be integral areas or sections of this unit, even if this is depicted differently in the drawings.

[0044] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0045] They show, schematically,

[0046] Figure 1 shows an isometric view of a humidifier.

[0047] Figure 2 shows a longitudinal section of the humidifier corresponding to section lines II in Figure 1, 06.10.2025

[0048] 12

[0049] Figure 3 shows an isometric external view of a humidifier lid.

[0050] Figure 4 shows an isometric interior view of the lid,

[0051] Figure 5 shows a top view of the lid from the outside,

[0052] Figure 6 shows a longitudinal section of the lid corresponding to section lines VI in Figure 5.

[0053] Figure 7 shows a cross-section of the lid corresponding to section lines VII in Figure 5.

[0054] Figure 8 is an enlarged detail VIII from Figure 2.

[0055] Figure 9 is an enlarged detail IX from Figure 8.

[0056] Figure 10 is an isometric sectional view of the detail from Figure 8 in the area of ​​section lines X in Figure 9,

[0057] Figure 11 shows an isometric view from inside the lid with a condensate filter element.

[0058] Figure 12 shows an isometric view of the condensate filter element from Figure 11.

[0059] Figure 13 is an isometric view as in Figure 12, but with a different embodiment of the condensate filter element, 06.10.2025

[0060] 13

[0061] Figure 14 shows an isometric view as in Figures 11 and 12, but in a further embodiment of the condensate filter element.

[0062] As shown in Figure 1, a humidifier 1 has a housing 2 that encloses or contains a membrane receiving chamber 3, for example, as shown in Figure 2. The humidifier 1 serves to humidify a dry first gas stream 4 by means of a moist second gas stream 5. The humidifier 1 is preferably intended for use in a fuel cell system and serves there to humidify cathode supply air by means of cathode exhaust air.

[0063] Advantageously, the housing 2 has at least one dry gas inlet 6 for supplying the dry first gas stream 4 to be humidified, in particular the dry cathode supply air to be humidified. Furthermore, the housing 2 has at least one moist gas outlet 7 for discharging the humidified first gas stream 4, in particular the humidified cathode supply air. The housing 2 is also equipped with at least one moist gas inlet 8 through which the moist second gas stream 5, in particular the moist cathode exhaust air, is supplied. In the example shown in Figure 1, two such moist gas inlets 8 are provided. In addition, the housing 2 is equipped with at least one dry gas outlet 9, which serves to discharging the dried second gas stream 5, in particular the dried cathode exhaust air. In the example shown in Figure 1, two such dry gas outlets 9 are provided. The individual gas streams are indicated by arrows in Figure 1.The first gas stream 4 is dry upon entry and moist upon exit, thus forming, as shown in Figure 1, a dry first gas stream 4t and a moist first gas stream 4f. The second gas stream 5, on the other hand, is supplied moist and discharged dry, so that, as shown in Figure 1, the second gas stream 5 forms a moist second gas stream 5f and a dry second gas stream 5t. 06.10.2025.

[0064] 14

[0065] In its installed state, humidifier 1 is integrated into a first gas supply system (not shown here), which carries the first gas 4, and a second gas supply system, which carries the second gas 5. In a fuel cell application, the first gas supply system is a cathode air supply system, while the second gas supply system is a cathode air exhaust system.

[0066] According to Figure 2, the humidifier 1 is also equipped with at least one membrane insert 10, which is inserted into the membrane receiving chamber 3, wherein the membrane insert 10 is fluidically separated from the first gas stream 4 and the second gas stream 5. As the fluid flows through the membrane insert 10, it transfers moisture from the second gas stream 5 to the first gas stream 4. Typically, the membrane insert 10 can be formed by a stack of appropriately arranged membranes made of a suitable membrane material. For example, the membrane material can be semipermeable or selectively permeable.

[0067] The housing 2, as shown in Figures 1 and 2, has a housing opening 11 dimensioned such that the respective membrane insert 10 can be inserted into the membrane receiving chamber 3 through the housing opening 11. According to the example shown in Figure 1, two membrane inserts 10 can be inserted into the membrane receiving chamber 3, each with a moist gas inlet 8 and a dry gas outlet 9. The housing 2 also has a cover 12 that closes the housing opening 11. As shown in Figures 2, 4, 6, 8 to 11, the cover 12 forms a condensate basin 14 on an inner surface 13 facing the membrane receiving chamber 3. This basin is designed to collect condensate, usually water, that forms in the membrane receiving chamber 3. Advantageously, the cover 12 is in the installed state shown on October 6, 2025.

[0068] 15

[0069] Humidifier 1 on the underside of the housing 2, so that condensate accumulating inside the housing 2 flows by gravity to the lid 12 and from there into the condensate trough 14.

[0070] As shown in Figures 3 to 11, the lid 12 has a heating channel 15 in the area of ​​the condensate tray 14, through which a heating medium 16 can flow, indicated by arrows in Figures 2 to 6 and 8 to 10. Preferably, a liquid heating medium 16 is used. The heating channel 15 has a heating medium inlet 17 for supplying the heating medium 16 and a heating medium outlet 18 for discharging the heating medium 16. During operation of the humidifier 1, the heating medium 16 flows through the heating channel 15 and thus heats the lid 12 in the area of ​​the condensate tray 14. Condensate within the condensate tray 14 can thereby be heated and more easily evaporated. Frozen condensate located in the condensate tray 14 can thus be thawed and liquefied. In the installed state of humidifier 1, the heating channel 15 is integrated into a heating circuit (not shown here) in which the heating medium circulates.When the humidifier 1 is used in a fuel cell system, the heating circuit can also be a cooling circuit for cooling a component of the fuel cell system, in particular a fuel cell stack.

[0071] As shown in Figures 8 to 10, the lid 12 has a condensate drain opening 19 on its inner surface 13 within the condensate basin 14, which is open towards the condensate basin 14. The condensate drain opening 19 is tubular in shape and has an internal thread 20. The humidifier 1 presented here is also equipped with a hollow screw 21, which is made of metal and includes a screw channel 22 and has an external thread 23 that is complementary to the internal thread 20. The hollow screw 21 is inserted into the condensate drain opening 19 via the external thread 23.

[0072] The screw is screwed into the lid 12. The hollow screw 21 penetrates the lid 12. An inlet end 24 of the screw channel 22 is axially open at an inner screw end 25 facing the condensate trough 14. An outlet end 26 of the screw channel 22 is axially open outside the lid 12 at an outer screw end 27 facing away from the condensate trough 14.

[0073] The humidifier 1 also has a connecting element 28, visible in Figures 2, 3, and 5 to 10, which is attached to the cover 12 by the hollow screw 21. The connecting element 28 has a condensate outlet 29 for draining condensate 16 and contains a condensate channel 30. The condensate channel 30 fluidically connects the outlet end 26 of the screw channel 22 to the condensate outlet 29. The humidifier 1 is also equipped with a control valve 31, which serves to control the fluidic connection between the screw channel 23 and the condensate channel 30. Thus, the control valve 31 controls the condensate drainage from the condensate basin 14. The control valve 31 is attached to the connecting element 28 in such a way that it interacts with the hollow screw 21 to control the outlet end 26 of the screw channel 22.For this purpose, the control valve 31 can have an adjustable valve element 32, which serves to control the outlet end 26 of the screw channel 22 and which is adjustable relative to the hollow screw 21. The embodiment shown here, in which the valve element 32 is adjustably arranged on the hollow screw 21, is preferred. The valve element 32 is visible at least in Figures 8 and 9 and partially in Figure 10.

[0074] As shown in Figure 9, the hollow screw 21 can have a screw head 33 that presses the connecting element 28 against the cover 12. The screw head 33 has an axially open annular groove 34 that surrounds a central area 35 of the screw head 33 and into which the valve member 32 engages axially. The screw channel 22 now extends into the screw head 33, as shown in Figure 9.

[0075] 17 that the outlet end 26 of the screw channel 22 is open in the central area 35. In the example shown, the valve element 32 is essentially cup-shaped and has a through-opening 36 opposite the outlet end 26 of the screw channel 22, which interacts with a valve seat 37 of the control valve 31. Figure 9 shows an intermediate position of the valve element 32 in which the through-opening 36 is a small distance from the valve seat 37. This allows condensate from the screw channel 22 to pass through the through-opening 36 into the condensate channel 30. When the control valve 31 is fully open, the distance between the through-opening 36 and the valve seat 37 is greater. When the control valve 31 is closed, the valve element 32 rests against the valve seat 37, so the distance is zero and the through-opening 36 is closed.

[0076] A particularly advantageous embodiment includes a cover plate 38 made of plastic, which is attached to the housing 2. The cover plate 38 has a heating section 39 of the heating channel 15, visible in Figures 6 to 10, which is open towards the membrane receiving chamber 3. The cover plate 38 also has the heating medium inlet 17 and the heating medium outlet 18. In particular, the heating section 39, the heating medium inlet 17, and the heating medium outlet 18 can be integrally formed on the cover plate 38. The cover 12 also has a recessed plate 40, visible in Figures 2, 4, and 6 to 11, which is made of metal and is attached to the inner surface 13 of the cover plate 38. The trough plate 14 has the condensate trough 14 and closes the heating section 39. As a result, the trough plate 40 is in direct contact with the heating medium 16.It is noteworthy that the condensate drain opening 19 is formed with the internal thread 20 on the tray plate 40. This means that the metallic hollow screw 21 is in direct contact with the metallic tray plate 40. 06.10.2025.

[0077] 18

[0078] The connecting element 28, as shown in Figure 10, can have a support body 41 made of plastic and a channel body 42 made of metal. The condensate outlet 29 is formed on the support body 41. The channel body 42 forms the condensate channel 30 and is enclosed by the support body 41. As shown in Figures 8 to 10, the hollow screw 21 is supported directly on the channel body 42. The hollow screw 21 presses the support body 41 against the cover 12 or the cover plate 38 via the channel body 42. Thus, the metal hollow screw 21 is also in direct contact with the metal channel body 42. The hollow screw 21 passes through the cover plate 38 in a through-opening 43 and presses the recessed plate 40 against the cover plate 38 from the inside. The hollow screw 21 also presses the support body 41 against the cover plate 38 from the outside.

[0079] As shown in Figure 10, the channel body 42 has a sleeve section 44 against which the hollow screw 21 is supported and which is fluidically connected to the outlet end 26 of the screw channel 22. The channel body 42 also has a pipe section 45 that fluidically connects the sleeve section 44 to the condensate outlet 29. The metallic channel body 42 can be a one-piece sheet metal forming part produced from a single sheet by forming. In the preferred embodiment shown here, the pipe section 45 connects tangentially to the sleeve section 44. Furthermore, the sleeve section 44 encloses the hollow screw 21 at the screw head 33, forming an annular space 46. Thus, when the control valve 31 is open, the condensate 16 flows from the condensate trough 14 through the screw channel 22 into the annular space 46 and from the annular space 46 through the pipe section 42 to the condensate outlet 29.

[0080] According to Figures 11 to 14, the humidifier 1 can expediently be equipped with a condensate filter element 47. The condensate filter element 47 06.10.2025

[0081] The 19 has a particle filter material 48 that is permeable to the condensate 16 but impermeable to solid impurities carried in the condensate 16 above a certain particle size. The condensate filter element 47 is arranged on the inside of the lid 13 such that it covers the condensate trough 14 and thus separates it from the membrane receiving chamber 3. Only filtered condensate 16 therefore enters the condensate trough 14.

[0082] The condensate filter element 47 can advantageously be attached to the tray plate 40. The condensate filter element 47 can be attached to the cover 12 or to the tray plate 40 in a replaceable manner, so that it can be replaced or cleaned for maintenance purposes. Alternatively, an embodiment is also conceivable in which the condensate filter element 47 is permanently attached to the cover 12 or to the tray plate 40.

[0083] The condensate filter element 47 can, in principle, be designed in any way, as long as it adequately fulfills the filtering function. Different embodiments of the condensate filter element 47 are explained in more detail below with reference to Figures 12 to 14, purely as examples.

[0084] As shown in Figure 12, the condensate filter element 47 can be flat and plate-shaped or circular, and as shown in Figure 10, it can be recessed into the inner surface 13 of the lid. In the example shown in Figure 12, the particle filter material 48 is segmented by means of several webs 49. The webs 49 can stiffen or stabilize the condensate filter element 47.

[0085] In the embodiment shown in Figure 13, the condensate filter element 47 is conically shaped, having a tip 50 projecting into the membrane receiving chamber 3 and a circularly circumferential rim 51, analogous to the disc-shaped condensate filter element 47 according to Figure 11 in the 06.10.2025

[0086] 20

[0087] The inner surface of the cover 13 can be recessed. Here, too, optional ribs 49 can be provided to stabilize and stiffen the condensate filter element 47, which simultaneously segment the particle filter material 48.

[0088] In the embodiment shown in Figure 14, the condensate filter element 47 is cylindrical, featuring a circular, flat end plate 52 projecting into the membrane receiving chamber 3 and a cylinder wall 53 which, in the assembled state, connects the cover 12 to the end plate 52. An edge 54 of the cylinder wall 53, facing away from the end plate 52, can be recessed into the inner surface 13 of the cover, analogous to the disc-shaped condensate filter element 47 shown in Figure 11. Here, too, optional webs 49 can be provided to connect the edge 54 to the end plate 52, which also stabilize and stiffen the condensate filter element 47. Furthermore, the webs 49 can again segment the particle filter material 48, which, in the example shown, is formed exclusively in the cylinder wall 53.

[0089] According to Figures 8 to 10, the hollow screw 21 can be sealed against the cover 12, in particular against the recessed plate 40, by a first radial seal 55. Furthermore, the hollow screw 21 can be sealed against the connecting element 28, in particular against the support body 41, by a second radial seal 56. In addition, the connecting element 28 can be sealed against the cover 12 by an axial seal 57. In the embodiments shown here, the axial seal 57 seals the support body 41 against the cover plate 39.

[0090] As can be seen in particular from Figures 4 and 6, the condensation- 06.10.2025

[0091] The 21 atmosphere well 14 is cylindrically shaped, thus defining a cylinder axis 58, which is also shown in Figures 3 and 5. The condensate drain opening 19, with its internal thread 20, defines a thread longitudinal axis 59, which is shown in Figures 3 and 5 and lies in a plane perpendicular to the cylinder axis 58. This plane extends parallel to the drawing plane in Figure 5. In particular, the thread longitudinal axis 59 can be perpendicular to the cylinder axis 58. The hollow screw 21 extends coaxially to the thread longitudinal axis 59 and therefore also runs transversely to the cylinder axis 58 and can, in particular, be radially oriented to the cylinder axis 58. The condensate channel 30 defines a channel longitudinal axis 60, at least in a longitudinal section leading to the condensate outlet 29, which is shown in Figures 3, 5, 7, and 10.The connecting element 28 is configured here such that the channel longitudinal axis 60 extends perpendicular to the cylinder axis 58 and perpendicular to the thread longitudinal axis 59.

[0092] As shown in Figures 3 and 5, the heating channel 15 has an inlet section 61 that connects the heating medium inlet 17 to the heating section 39. The heating channel 15 also has an outlet section 62 that connects the heating section 39 to the heating medium outlet 18. Inlet section 61 and outlet section 62 are both straight and aligned parallel to each other and parallel to the longitudinal thread direction 59. The hollow screw 21 is located between the inlet section 61 and the outlet section 62 and is connected to the condensate trough 14. In the example shown here, the heating section 39 extends along a circular arc over 180° to connect the inlet section 61 to the outlet section 62. Preferably, the inlet section 61 and the outlet section 62, as well as the heating medium inlet 17 and the heating medium outlet 18, are integrally formed on the cover 12. October 6, 2025

[0093] 22

[0094] In particular, Figures 3 and 5 also show connection elements 63, one of which is attached to the heating medium inlet 17 and one to the heating medium outlet 18 to simplify integration into a heating circuit. Figures 3, 5, and 7 also show a condensate connection element 64, which is connected to the condensate outlet 29 and serves to drain the condensate from the condensate outlet 29. The condensate connection element 64 can be electrically heated.

[0095] The trough plate 40 can have several cooling fins 65 as shown in Figure 4, which project into the membrane receiving chamber 3 and / or into the condensate trough 14.

[0096] A22036WG 0.2025

[0097] 23

[0098] Reference symbol list

[0099] humidifier

[0100] Housing

[0101] Membrane receiving space dry first gas stream moist second gas stream

[0102] Dry gas inlet

[0103] Moist gas outlet

[0104] Moist gas inlet

[0105] T dry gas outlet

[0106] Membrane insert

[0107] Case opening

[0108] Lid

[0109] Inside of lid

[0110] Condensate well

[0111] heating channel

[0112] Heating element

[0113] Heating medium inlet

[0114] heating medium outlet

[0115] Condensate drain opening

[0116] internal thread

[0117] Hollow screw

[0118] screw channel

[0119] external thread

[0120] Recessed inner screw end

[0121] Omitted 025

[0122] 24 outer screw end connecting element condensate outlet condensate channel control valve valve element screw head ring groove

[0123] Central area, passage opening, valve seat

[0124] Cover plate heating section

[0125] Trough plate, support body, channel body, through opening, sleeve section, pipe section, annular space

[0126] Condensate filter element, particle filter material, bridge

[0127] Pointed edge end plate cylinder wall edge first radial seal second radial seal

[0128] Axial seal

[0129] Cylinder axis

[0130] Thread longitudinal axis

[0131] Canal longitudinal axis

[0132] Entrance section

[0133] outlet section

[0134] Connection element

[0135] Condensate connection element

[0136] cooling fin

Claims

October 6, 2025 26 Claims 1. Humidifier (1) for humidifying a dry first gas stream (4) by means of a moist second gas stream (5), in particular for a fuel cell system, comprising a housing (2) having a condensate trough (14) for collecting condensate accumulating in the housing (2), wherein the housing (2) has a heating channel (15) in the region of the condensate trough (14) through which a heating medium (16) can flow, wherein a condensate drain opening (19) is located inside the condensate trough (14), wherein a condensate outlet (29) for discharging condensate is located on the outside of the housing (2) and is fluidically connected to the condensate drain opening (19), characterized in that the condensate drain opening (19) has an internal thread (20), and that the humidifier (1) has a hollow metal screw (21) extending from the housing (2), which contains a screw channel (22) and has an external thread (23). exhibitswith which the hollow screw (21) is screwed into the condensate drain opening (19), that the humidifier (1) has a connecting element (28) which is attached to the housing (2) by the hollow screw (21), which has the condensate outlet (29) and which contains a condensate channel (30) which fluidically connects the screw channel (22) to the condensate outlet (29).

2. Humidifier (1) according to claim 1, characterized in that the housing (2) has a membrane receiving chamber (3), 27 that the humidifier (1 ) at least one in the membrane receiving space (3) inserted membrane insert (10) which is supplied by the first gas stream (4) and is fluidically separated from the second gas stream (5) and, during its flow, transfers moisture from the second gas stream (5) to the first gas stream (4), that the housing (2) has a housing opening (11) through which the respective membrane insert (10) can be inserted into the membrane receiving chamber (3), that the housing (2) has a cover (12) which covers the housing opening (11) closes off that the lid (12) forms the condensate basin (14) on an inner side (13) of the lid facing the membrane receiving space (3) for collecting condensate accumulating in the membrane receiving space (3), that the heating channel (15) is located in the area of ​​the condensate basin (14) on the lid (12) is designed such that the heating channel (15) has a heating medium inlet (17) formed on the cover (12) for supplying the heating medium (16) and a heating medium outlet (18) formed on the cover (12) for discharging the heating medium (16), that the condensate drain opening (19) on the cover (12) is formed on the inside (13) of the cover within the condensate trough (14), that the hollow screw (21) penetrates the cover (12), that an inlet end (24) of the screw channel (22) is open at an inner screw end (25) facing the condensate trough (14), that an outlet end (26) of the screw channel (22) is open outside the cover (12) at an outer screw end (27) facing away from the condensate trough (14), that the connecting element (28) with the hollow screw (21) on the cover (12) is attached, October 6, 2025 28 that the condensate channel (30) fluidically connects the outlet end (26) of the screw channel (22) with the condensate outlet (29).

3. Humidifier (1 ) according to claim 1 or 2, characterized in that the humidifier (1 ) has a control valve (31 ) for controlling the fluidic connection between the screw channel (22) and the condensate channel (30), that the control valve (31 ) is attached to the connecting element (28) and cooperates with the hollow screw (21 ) to control an outlet end (26) of the screw channel (22).

4. Humidifier (1 ) according to claim 3, characterized in that the control valve (31 ) has an adjustable valve element (32) for controlling the outlet end (26) of the screw channel (22), which is adjustably arranged on the hollow screw (21 ).

5. Humidifier (1) according to claim 4, characterized in that the hollow screw (21) has a screw head (33) which presses the connecting element (28) against the cover (12), that the screw head (33) has an axially open annular groove (34) which encloses a central area (35) of the screw head (33) and into which the valve element (32) engages, that the screw channel (22) extends into the screw head (33) so that the outlet end (26) of the screw channel (22) is open in the central area (35). October 6, 2025 29 6. Humidifier (1) according to one of the preceding claims, but at least according to claim 2, characterized in that the lid (12) has a lid plate (38) made of plastic, which is attached to the housing (2), which has a heating section (39) of the heating channel (15) open towards the membrane receiving chamber (3), the heating medium inlet (17) and the heating medium outlet (18), that the lid (12) has a trough plate (40) made of metal, which is attached to the inside (13) of the lid plate (38), which has the condensate trough (14) and which closes the open heating section (39), that the condensate drain opening (19) is formed with the internal thread (20) on the trough plate (40).

7. Humidifier (1 ) according to one of the preceding claims, characterized in that the connecting element (28) has a support body (41 ) made of plastic and a channel body (42) made of metal forming the condensate channel (30), which is enclosed by the support body (41 ), that the hollow screw (21 ) is supported directly on the channel body (42) and presses the support body (41 ) against the housing (2), in particular against the cover (12) via the channel body (42).

8. Humidifier (1 ) according to claims 6 and 7, characterized in that the hollow screw (21 ) passes through the cover plate (38) in a through-opening (43), presses the trough plate (40) against the cover plate (38) from the inside and presses the support body (41 ) against the cover plate (38) from the outside. October 6, 2025 30 9. Humidifier (1) according to claim 7 or 8, characterized in that the channel body (42) has a sleeve section (44) on which the hollow screw (21) is supported and which is fluidically connected to the outlet end (26) of the screw channel (22), and that the channel body (42) has a pipe section (45) which fluidically connects the sleeve section (44) to the condensate outlet (29).

10. Humidifier (1 ) according to claim 9, characterized in that the pipe section (45) connects tangentially to the sleeve section (44), and / or that the sleeve section (44) coaxially surrounds the hollow screw (21 ) forming an annular space (46).

11. Humidifier (1) according to one of the preceding claims, characterized in that the humidifier (1) has a condensate filter element (47) that covers the condensate basin (14), so that condensate accumulating in the housing only enters the condensate basin (14) through the condensate filter element (47).

12. Humidifier (1 ) according to claim 11 , characterized in that the condensate filter element (47) is arranged on the inside of the lid (13) and separates the condensate trough (14) from the membrane receiving chamber (3), and / or that the condensate filter element (47) is attached to the trough plate (40). October 6, 2025 31 13. Humidifier (1) according to claim 11 or 12, characterized in that the condensate filter element (47) is plate-shaped and flat and can be recessed in the inside of the lid (13) and has a particle filter material (48) permeable to condensate, or that the condensate filter element (47) is conically shaped and has a particle filter material (48) permeable to condensate, a tip (50) projecting into the membrane receiving chamber (3) and a circumferential rim (51) which can be recessed in the inside of the lid (13), or that the condensate filter element (47) is cylindrically shaped and has an end plate (52) projecting into the membrane receiving chamber (3), a cylinder wall (53) connecting the end plate (52) to the lid (12) and a particle filter material (48) permeable to condensate which is attached to the end plate (52) and / or to the cylinder wall (53) is formed.

14. Humidifier (1 ) according to one of the preceding claims, characterized in that the hollow screw (21 ) is sealed with a first radial seal (55) against the cover (12) and with a second radial seal (56) against the connecting element (28), and / or that the connecting element (28) is sealed with an axial seal (57) against the cover (12).

15. Humidifier (1) according to one of the preceding claims, characterized in that the condensate trough (14) is cylindrical and defines a cylinder axis (58), .2025 32 that the condensate drain opening (19) with the internal thread (20) defines a thread longitudinal axis (59) which is perpendicular to the cylinder axis (58) plane, that the hollow screw (21) extends coaxially to the longitudinal axis of the thread (59), that the condensate channel (30) defines a channel longitudinal axis (60) which is perpendicular to the cylinder axis (58) and perpendicular to the longitudinal axis of the thread (59) extends.

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