Drying device, in particular recirculating air drying device

Abstract

The invention relates to a drying device, in particular a circulating air drying device, for a dishwasher, comprising an intake duct (10) providing an air intake opening (11), an outlet duct (12) providing an air outlet opening (13), and a fan (14) to which the intake duct (10) on the air intake side and the outlet duct (12) on the air outlet side are fluidically connected, wherein the intake duct (10) and the outlet duct (12) are arranged next to one another at least in sections with a partition (17) interposed, and wherein the intake duct (10) and the outlet duct (12) each have a condensate channel (18, 19) which are each arranged on an inner surface (26, 27) of the duct, wherein the partition (17) has an opening (20) through which the two condensate channels (18, 19) interact fluidically.

Description

[0001] The invention relates to a drying device, in particular a circulating air drying device, for a dishwasher, having an attachment channel providing an air intake opening, an outlet channel providing an air outlet opening and a fan to which the intake channel is fluidically connected on the air intake side and the outlet channel on the air outlet side, wherein the intake channel and the outlet channel are arranged next to one another at least in sections with a partition wall interposed, and wherein the intake channel and the outlet channel each have a condensate gutter, each of which is arranged on an inner surface of the channel.

[0002] Dishwashers in general and those with a drying device of the type mentioned above in particular are well known from the state of the art, which is why there is no need for separate printed evidence at this point.

[0003] A dishwasher, particularly a household dishwasher, of the typical design has a wash tub that provides a wash chamber and serves to hold the items to be cleaned. In the case of a household dishwasher, the items to be washed are, in particular, crockery and cutlery.

[0004] When a dishwasher is used as intended, the dishes are dried after cleaning. Various drying methods are known in the art, including hot-air drying, in which the dishes to be dried are exposed to previously heated drying air. The air in the dishwasher's wash tub can be used as the drying air, in which case hot-air drying takes place in recirculation mode. Alternatively and / or in combination with this, fresh air drawn from the atmosphere surrounding the dishwasher can also be used for drying.

[0005] Regardless of whether hot-air drying is carried out using recirculated air and / or fresh air, a drying device is used for air flow and heating. This device provides appropriate air ducts and is equipped with a fan and a heating element. Furthermore, temperature sensors can be provided to regulate the heating output and monitor the system.

[0006] A generic drying device for hot-air drying has an intake duct and an outlet duct. The intake duct provides an air intake opening, while the outlet duct has an air outlet opening. During intended use, the intake duct is supplied with drying air through the air intake opening, which is then conveyed through the outlet duct to the air outlet opening. The drying air leaving the drying device through the air outlet opening then enters a washing compartment of a dishwasher that interacts with the drying device.

[0007] The drying system is equipped with a fan to convey the drying air. The intake duct on the air intake side and the outlet duct on the air outlet side are connected to this fan.

[0008] To heat the drying air, the drying device also has a heating element. This is typically located in the outlet duct, meaning that the air drawn in by the fan passes through the heating element before leaving the drying device through the air outlet.

[0009] When a dishwasher is used as intended, water spray from the washing tub can enter the drying unit through the air outlet and / or the air intake. Furthermore, steam generated in the washing tub during a wash cycle can enter the drying unit through the openings on the drying unit side, where it then condenses inside the ducts, resulting in the formation of condensate.

[0010] To prevent a failure of the drying device's fan, the entry of large quantities of water into the drying device must be prevented. For this purpose, condensate gutters are used according to a prior art solution. These are formed on the inner surface of the duct and intercept condensate forming inside a duct before it can flow down the inner surface of the duct and reach the fan. The condensate gutters guide intercepted condensate to the respective duct opening. According to the state of the art, both the intake duct and the outlet duct each have a condensate gutter, with the condensate gutter of the intake duct interacting fluidically with the air intake opening, and the condensate gutter of the outlet duct interacting with the air outlet opening.

[0011] Although this prior art design has proven itself in everyday practical use, there is still room for improvement. This is particularly true because, depending on the design of the intake and exhaust ducts, or the respective duct layout, the previously described condensate channel design is not always possible due to space constraints. Therefore, the object of the invention is to propose an alternative solution to the previously known condensate channel design that effectively prevents excessive amounts of water from entering the fan of the drying device.

[0012] To achieve this object, the invention proposes a drying device of the generic type, which is characterized in that the partition wall has an opening through which the two condensate channels interact fluidically.

[0013] The special feature of the inventive design is that a pressure-side condensate channel, i.e., a condensate channel in the outlet channel, interacts fluidically with a vacuum-side condensate channel, i.e., a condensate channel in the intake channel. For this purpose, the partition wall separating the two channels is equipped with an opening through which the two condensate channels are fluidically connected. Condensate can be transferred from one condensate channel to the other through this opening.

[0014] According to the current state of the art, a condensate channel in a duct is fluidically associated with the corresponding opening of the duct. The condensate channel of the intake duct drains through the air intake opening, and the condensate channel of the exhaust duct drains through the air outlet opening. A fluidic connection between the two condensate channels is not provided.

[0015] In contrast to this previously known solution, the inventive design now provides a fluidic connection between the two condensate channels of the outlet channel and the intake channel, which opens up the possibility of draining through only one of the two openings of the drying device, preferably the opening located at the bottom in vertical direction. Depending on the design of the drying device, this can thus be the opening of the outlet channel or the opening of the intake channel, thus the air intake opening.

[0016] The design possibility provided by the inventive embodiment of draining the condensate forming in both channels exclusively through a single opening advantageously provides the option, in particular, of positioning the condensate gutter of the outlet channel at a different location in the outlet channel than has previously been provided for in the prior art. This creates the possibility of being able to use the available installation space in a different way. In particular, it is advantageously possible to equip both channels with a raised section for improved protection against the ingress of splash water and to arrange the heating device provided for heating the drying air on the outlet channel side in the region of the raised section on the outlet channel side. This enables optimized heating of the drying air and, at the same time, improved protection against the ingress of splash water.Such use of installation space is not possible according to the state of the art due to the design of the condensate gutters.

[0017] The design according to the invention makes this possible because, in contrast to the prior art, condensate channels are provided that are fluidically connected to one another via an opening in the partition wall separating the two channels. As a result of this structural design, drainage is possible, as described above, solely via the opening in the drying device, which is located at the lowest point in height.

[0018] Therefore, according to a further feature of the invention, it is proposed that the condensate channels interact fluidically with the opening located at the lowest vertical position. When used as intended, condensate forming within the channels can be trapped and discharged to the outside via the opening of the drying device located at the lowest vertical position. In the case of recirculation drying, the condensate is discharged into the dishwasher's wash chamber.

[0019] According to a further feature of the invention, it is provided that the opening is designed to minimize cross-flow of drying air from the intake duct into the outlet duct and vice versa.

[0020] The aperture provided for the fluidic connection of the condensate channels allows not only condensate to flow through, but also drying air during intended use. In particular, due to the different pressures prevailing in the ducts, drying air can be drawn, virtually bypassing the fan, from the intake duct on the negative pressure side into the outlet duct on the positive pressure side. The associated pressure losses must be avoided or at least minimized, which is why it is recommended to prevent, as far as possible, any crossflow of drying air through the aperture during intended use. The aperture is designed accordingly for this purpose.

[0021] According to a first alternative of the invention, this device can be formed in that the edge contour of the partition wall surrounding the opening has an offset oriented transversely to the partition wall. Alternatively, according to a further feature of the invention, the opening is equipped with a labyrinth guide. Other contours are also conceivable. The decisive factor is that, through a corresponding design of the opening, the static pressure difference between the suction and pressure sides and the negative pressures generated by air flows cancel each other out. Undesired pressure losses in the air flow are thus avoided, while at the same time it is ensured, as already described, that condensate forming on the pressure side can pass through the opening to the negative pressure side and thus to the air outlet opening.

[0022] According to a further feature of the invention, it is provided that a condensate channel is provided by a strip-shaped rib which is applied to the inner surface of the channel.

[0023] According to this embodiment, the condensate channel is formed by a rib. This protrudes from the inner surface of the channel into the channel space provided by the channel. The rib is essentially placed on the inner surface of the channel. The rib preferably has a height of at least 3.5 mm, preferably 4 mm or more. This ensures that even larger condensate drops can be safely guided by the channel and directed to the air intake opening.

[0024] According to a further feature of the invention, the rib can be L-shaped in cross-section. This design serves to improve the guidance of a droplet through the condensate channel; in particular, the design ensures that a condensate droplet guided by the condensate channel cannot easily overflow the channel's longitudinal edge.

[0025] According to an alternative embodiment, the condensate channel is formed as a recess. The recess can be designed either as an indentation or as a bulge in the channel wall. A bulge has the advantage that it does not increase the channel width. However, when used as intended, less favorable flow conditions arise within the channel. This disadvantage is not inherent in the design of the recesses as bulges. However, the geometric dimension of the channel increases in the width direction, which may not be possible due to space constraints. In this respect, the design of recesses as bulges is preferred.

[0026] According to a further feature of the invention, the facing inner surfaces of two channel walls of a channel each have a condensate channel. Thus, at least two channel channels are provided per channel, arranged opposite each other on the associated inner surfaces. Both large surfaces of a channel are thus equipped with a condensate channel, so that the condensate accumulating on both large surfaces can be drained away in the manner described above.

[0027] According to a further feature of the invention, the condensate channels are arranged offset from one another in the vertical direction. This configuration is particularly preferred when the condensate channels are formed by depressions or indentations. Potential negative influences on the pressure loss that occurs during intended use can thus be minimized.

[0028] In order to drain water droplets effectively, the condensate gutters should protrude into the air duct of a duct to a height of at least 3.5 mm, although 4 mm or more is better. The height of the condensate gutters can be selected depending on the overall incline of the respective condensate gutter. The steeper the condensate gutter is from the highest to the lowest point, the smaller the height can be in order to drain water droplets efficiently. The condensate drainage should therefore be as steep as possible, as long as the air duct allows it. For example, for an incline of 45° or more, a gutter height of 3.5 mm is sufficient. For an incline of only 15°, for example, the gutter height should be greater, for example 4 mm or more.

[0029] The inventive design provides a construction that helps prevent undesirably large amounts of water from entering the fan. Splash water and condensate forming on the walls of the ducts can be channeled back into the wash chamber by means of the grooves provided according to the invention. The grooves of the two ducts are fluidly connected and drain through one and the same opening, namely the opening located lowest in height. This creates the structural possibility of being able to use the duct space provided by the outlet duct in a different way, especially in the area of ​​elevation, for example, to accommodate a heating device and / or heat protection panels.

[0030] The invention further proposes a dishwasher having a drying device of the type according to the invention. Such a dishwasher offers the advantages already described.

[0031] According to a further feature of the invention, the dishwasher comprises a washing compartment for receiving the items to be cleaned, wherein the channels of the drying device are arranged outside the washing compartment on a washing compartment wall, preferably a washing compartment side wall, with the air intake opening and the air outlet opening each opening into the washing compartment provided by the washing compartment. This results in a design that uses minimal installation space, enabling a standard-sized washing compartment. Furthermore, this design advantageously permits recirculation operation of the drying device.

[0032] Further features and advantages of the invention will become apparent from the following description with reference to the figures. Fig. 1 shows a schematic perspective view of a dishwasher according to the invention; Fig. 2 in a schematic side view the dishwasher according to Fig. 1; Fig. 3 in a schematic side view, a section of the drying device of the dishwasher according to the Fig. 1 and Fig. 2; Fig. 4 shows a schematic side view of a drying device according to the invention according to a first embodiment; Fig. 5 shows a schematic side view of a drying device according to the invention according to a second embodiment; Fig. 6 schematic side views of alternatively designed condensate gutters; Fig. 7 shows a schematic perspective view of a condensate channel according to a first embodiment; Fig. 8 shows a schematic perspective view of a condensate gutter according to a second embodiment; Fig. 9 shows a schematic perspective view of a condensate gutter according to a third embodiment; Fig. 10 shows a schematic perspective view of a condensate gutter according to a fourth embodiment; Fig. 11 shows a schematic perspective view of a condensate gutter according to a fifth embodiment; Fig. 12 shows a schematic perspective view of a condensate gutter according to a sixth embodiment.

[0033] Fig. 1 shows a schematic perspective view of a dishwasher 1 according to the invention.

[0034] The dishwasher 1 has, in a manner known per se, a washing container 2 providing a washing chamber 3, which, when used as intended, serves to hold items to be cleaned.

[0035] For the purpose of hot air drying of dishes in the washing container 2, the dishwasher 1 has a drying device 9.

[0036] As can be seen from a summary of the Fig. 1 and Fig. 2, the drying device 9 has an intake duct 10 on the one hand and an outlet duct 12 on the other hand for guiding drying air. Furthermore, the drying device 9 has a fan 14, to which the intake duct 10 on the air intake side and the outlet duct 12 on the air outlet side are fluidically connected.

[0037] The fan 14 of the drying device 9 is arranged in the base area, ie in the vertical direction 8 below the washing container 2. The two channels, ie the intake channel 10 and the outlet channel 12, are arranged on the outside of the washing container 2 on a washing container side wall 4 of the washing container 2.

[0038] As can be seen particularly from the presentation after Fig. 1, the washing container 2 has two washing container side walls 4, a ceiling part 5, a base part 6 and a rear wall 16. Opposite the rear wall 16 there is a loading opening 7 through which the washing container 2 can be loaded with items to be washed when used as intended.

[0039] As can be further seen from a summary of the Fig. 1 and Fig. 2, the intake duct 10 of the drying device 9 provides an air intake opening 11.

[0040] Accordingly, the outlet channel 12 has an air outlet opening 13. Both openings, ie the air intake opening 11 and the air outlet opening 13, both open into the washing chamber 3. Accordingly, in the intended use, an air flow can take place, as shown in Fig. 2 arrows can be seen.

[0041] In accordance with the representation according to Fig. 2, when the drying device 9 is used as intended, recirculation mode occurs. The fan 14 draws in drying air from the wash cabinet 3 through the air intake opening 11. This drying air passes through the intake duct 10 and through the fan 14 to the outlet duct 12. A heating device 15 is integrated into the outlet duct 12, by means of which the drying air passing through the outlet duct 12 is heated. The heated drying air leaves the drying device 9 through the outlet opening 13 provided by the outlet duct 12, where it is returned to the wash cabinet 3.

[0042] As can be seen particularly from the detailed presentation after Fig. 3, the intake duct 10 and the outlet duct 12 are arranged next to one another at least in sections, with a partition wall 17 interposed. By means of the partition wall 17, the negative pressure side of the intake duct 10 and the positive pressure side of the outlet duct 12 are thus separated from one another in terms of flow.

[0043] Both the intake duct 10 and the outlet duct 12 each have a condensate channel 18 and 19 respectively, as can be seen from the illustration according to Fig. 4. The condensate channels 18 and 19 are each arranged on a channel surface 26 and 27 of the channel wall 24 and 25 of the corresponding channel 10 and 12, respectively.

[0044] According to the invention, the partition wall 17 has an opening 20 through which the two condensate channels 18 and 19 are fluidically connected to one another, as can be seen from a first embodiment of Fig. 4 and using a second embodiment from Fig. 5 results.

[0045] The condensate channels 18 and 19 of the two channels 10 and 12 interact fluidically by means of the opening 20 provided in the partition wall 17, which advantageously enables drainage via only one of the two openings 11 and 13, namely, in the illustrated embodiment, via the lower air intake opening 11 in the vertical direction 8. Thus, not only the intake channel 10 is drained via the air intake opening 11, but also the outlet channel 12.

[0046] As can be seen from a summary of the Fig. 2 to 4, both the intake duct 10 and the outlet duct 12 each provide a raised portion 22. This serves to allow spray water that inevitably penetrates through a respective opening 11 or 13 during intended use to flow out again through the respective opening, without there being a risk that the spray water can reach the fan 14 in significant quantities. The structural design according to the invention now makes it possible to better utilize the available installation space with a view to optimized drying. In particular, it is possible to arrange the heating device 15 in the flow direction in the immediate vicinity of the raised portion 22 of the outlet duct 12 on the air outlet opening side, as is the case Fig. 2. This is only possible because the condensate channel on the outlet channel side is fluidically connected to the condensate channel 19 on the intake channel side, thus enabling drainage of both channels via the air intake opening 11.

[0047] This is how Fig. 4, a drainage of possible condensate takes place via a further opening 21, which is formed on the intake duct side, namely in the raised wall 23.

[0048] In order to avoid possible pressure losses between the pressure side and the suction side due to the opening 20 provided according to the invention during normal operation, the opening 20 is designed to minimize cross-flows of drying air from the intake duct 10 into the outlet duct 12 and vice versa. For this purpose, according to the embodiment according to Fig. 4, an edge contour 28 surrounding the opening 20 is provided, which has an offset aligned transversely to the partition wall 17. Alternatively, a labyrinth guide 29 can be provided, as in Fig. 5. These design measures achieve pressure equalization between the suction and pressure sides, so that undesirable suction effects of drying air from the intake duct 10 into the outlet duct 12 through the opening 20 are largely avoided.

[0049] How Fig. 6 shows two exemplary embodiments, a condensate channel 18 can be oriented differently with regard to the angle of inclination to the horizontal. Fig. 6 shows a first condensate trough 18 which is at an inclination angle 31 of 45° and a second condensate trough 18 which has an inclination angle 32 of 15°.

[0050] It is desirable that a water droplet caught by a condensate gutter 18 or 19 does not flow over the longitudinal edge of the gutter, but is guided from the gutter in the longitudinal direction of the gutter to one of the openings 11, 13 in the flushing chamber (i.e. to the air outlet opening 13 or air intake opening 11). To ensure this, the gutter must have a certain extension into the duct space provided by the duct. The rule here is that the smaller the angle of inclination, the greater the extension must be. If, for example, the gutter has an angle of inclination 31 of 45°, an extension of the gutter into the air duct of 3.5 mm is sufficient. For smaller angles of inclination, the extension must be correspondingly greater.

[0051] Since it is desirable to keep the extension of a gutter into the sewer space as small as possible in order to avoid unnecessary pressure losses, larger angles of inclination are preferred.

[0052] The Fig. Figures 7 to 13 each show different gutter designs in a schematic perspective view.

[0053] The Fig. 7 and Fig. 8 show a condensate channel design, according to which a condensate channel is provided by a strip-shaped rib 33, which is applied to the channel inner surface 26 of a channel wall 24. The rib 33 has a height of at least 3.5 mm.

[0054] The embodiment according to Fig. 7 shows a rib which is L-shaped in cross section. Fig. 8, however, shows a merely web-shaped design of the rib 33.

[0055] The Fig. 9 and Fig. 10 show the embodiment of a condensate channel, according to which a condensate channel is provided by a recess 34 introduced into the channel wall 24 of the associated channel inner surface 26. The recess 34 is produced according to Fig. 9 by a curvature 35 of the channel wall 24, whereas the embodiment according to Fig. 10 shows a depression 34 which results as a bulge 36 of the channel wall 24.

[0056] As the representation according to Fig. As can be seen in Figure 11, the formation of a depression 34 by a curvature 35 ensures that the clear outer width of the channel does not increase. However, the protrusion of the depressions 34 into the channel space provided by the channel results in a pressure loss with respect to the drying air flowing through the channel. To minimize this pressure loss, the depressions 34 or condensate channels 18 are preferably arranged offset from one another in the vertical direction 8, as can be seen from Fig. 11 results.

[0057] Fig. 12 shows depressions 34 resulting from a bulge 36 of the channel wall 24. The advantage of this design is that pressure losses within the flow can be avoided, although the clear outer dimensions of the channel increase in the area of ​​the depressions 34, which may not be desirable for space-related reasons. Therefore, depending on the installation situation, either a design according to Fig. 11 or an execution according to Fig. 12 to choose. Reference symbol 1 dishwasher 2 rinsing containers 3 Washing-up area 4 Rinse tank side wall 5 Ceiling part 6 Base part 7 Loading opening 8 Altitude direction 9 Drying device 10 intake duct 11 Air intake opening 12 exhaust channel 13 Air outlet opening 14 blowers 15 Heating device 16 Rear wall 17 Partition wall 18 Condensate gutter 19 Condensate gutter 20 Breakthrough 21 Breakthrough 22 Cant 23 superelevation wall 24 Channel wall 25 Channel wall 26 Channel inner surface 27 Channel inner surface 28 Edge contour 29 Labyrinth tour 30 exterior wall 31 angles 32 angles 33 rib 34 Deepening 35 Vaulting 36 bulge

Claims

[1] Drying device, in particular a circulating air drying device, for a dishwasher, with an intake duct (10) providing an air intake opening (11), an outlet duct (12) providing an air outlet opening (13) and a fan (14), to which the intake duct (10) on the air intake side and the outlet duct (12) on the air outlet side are fluidically connected, wherein the intake duct (10) and the outlet duct (12) are arranged next to one another at least in sections with a partition (17) interposed, and wherein the intake duct (10) and the outlet duct (12) each have a condensate channel (18, 19) which are each arranged on a duct inner surface (26, 27), characterized by that the partition wall (17) has an opening (20) through which the two condensate channels (18, 19) interact fluidically. [2] Drying device according to claim 1, characterized bythat the condensate channels (18, 19) interact fluidically with the opening (11) arranged at the bottom in the height direction (8). [3] Drying device according to claim 1 or 2, characterized by that the opening (20) is designed to minimize cross flows of drying air from the intake duct (10) into the outlet duct (12) and vice versa. [4] Drying device according to claim 3, characterized by that the edge contour (28) of the partition wall (17) surrounding the opening (20) has an offset aligned transversely to the partition wall (17). [5] Drying device according to claim 3, characterized by that the opening (20) provides a labyrinth guide (29). [6] Drying device according to one of the preceding claims, characterized by that a condensate channel (18; 19) is provided by a strip-shaped rib (33) which is applied to the channel inner surface (26, 27). [7] Drying device according to claim 6, characterized by that the rib (33) has an L-shaped cross section. [8] Drying device according to one of the preceding claims 1 to 5, characterized by that a condensate channel (18, 19) is provided by a recess (34) made in the channel wall (24, 25) of the associated channel inner surface (26, 27). [9] Drying device according to claim 8, characterized by that the recess (34) is formed by a bulge (35) or by a bulge (36) of the channel wall (24, 25). [10] Drying device according to one of the preceding claims, characterized by that the mutually facing channel inner surfaces (26, 27) of two channel walls (24, 25) of a channel (10, 12) each have a condensate groove (18, 19). [11] Drying device according to claim 10, characterized bythat the condensate channels (18, 19) are arranged offset from one another in the height direction (8). [12] Drying device according to one of the preceding claims, characterized by that a condensate channel (18, 19) has an extension into the channel space provided by a channel (10, 12) of 3.5 mm or more. [13] Drying device according to one of the preceding claims, characterized by that the inclination of a condensate trough (18, 19) is between 15° and 45° to the horizontal. [14] Dishwasher with a drying device (9) according to one of the preceding claims 1 to 13. [15] Dishwasher according to claim 14, with a washing container (2) providing a washing chamber (3) for receiving items to be cleaned, wherein the channels (10, 12) of the drying device (9) are arranged on the outside of the washing container (2) on a washing container wall (4) and wherein the air intake opening (11) and the air outlet opening (13) open into the washing chamber (3).

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