EP0521815A1 - Dishwasher with an opening or similar connecting the washing compartment with the ambient air - Google Patents

Abstract

In a dishwasher (1) with a washing compartment (3) which can be closed by means of an appliance door (2), a vent (4) or the like for the dishwasher container in the appliance door (2), which vent connects the washing compartment to the ambient air, and a mixing chamber (5) for removal of the moist air from the washing compartment when the dishes are being dried, a separate fresh air duct (6) opens out into the mixing chamber (5). A fan (7), which is arranged downstream of the fresh air duct (6) and the vent (4) for the dishwasher container, is provided for transport of the mixing air. The mixing chamber (5) can be set to a modifiable mixing ratio of the fed-in fresh air to the moist air sucked from the washing compartment, while the volumetric flow rate of mixing air remains constant. By these measures, optimum removal of vapour from the washing container in order to improve drying of the dishes, with a shorter program running time and without the visible formation of vapour, is achieved for a small structural outlay and a very small space requirement. <IMAGE>

Description

The subject matter of the invention relates to a dishwasher with a wash chamber closable by a door and with a wash tank vent opening connecting the wash chamber to the ambient air or the like in the appliance door and a mixing chamber for removing the moist air from the wash chamber when drying dishes, in the mixing chamber a separate fresh air duct opens and a blower is provided for the transport of the mixed air.

Such a dishwasher is known from German Offenlegungsschrift 3,418,304.

The known dishwasher has a vent from the wash cabinet to remove the moist air from the wash container when drying dishes. The ventilation duct opens into a separate fresh air duct running in the appliance door, which is followed by a mixing chamber. A common blower with two fluidically separated impellers - each for one channel - ensures that the moist exhaust air is removed from the flushing tank. The air quantities conveyed by the two impellers are dimensioned so that the mixed air discharged into the environment does not fall below the dew point, so that no steam or vapors are visible. In the known device, a complex fan with two separate fan chambers is required. In addition, there is always a constant volume flow ratio over the entire running time of the fan. Furthermore, the program duration in the drying section of this known dishwasher cannot be shortened without disadvantages in the dish drying.

From DE-OS 38 42 997 it is also known in a dishwasher to provide a blower with only one impeller which conveys outside air drawn in in the floor area of the device in predeterminable amounts both into the fresh air duct and via an additional secondary air duct into the washing container. For this purpose, the fresh air duct and the secondary air duct are guided to a common flow chamber arranged in the base area of the device, which is connected on the pressure side to the blower. The wash cabinet has a ventilation opening in the appliance door that opens into the mixing chamber. To the mixing chamber the fresh air duct led over the flow chamber is also laid.

In this known state of the art, a flow chamber with a control flap mechanism is required in addition to the mixing chamber, which is not easily accessible in the case of service due to the concealed arrangement in the lower part of the device housing. It is also to be regarded as a disadvantage in the known device that an excess pressure is built up in the washing tank by the additional fresh air conducted in the drying section by the fan in the bypass through the washing tank, whereby it may be. U. to a visible steam leak at unwanted leaks in the rinse tank - z. B. under the worktop - can come. In addition, in the known embodiment, all air inlet and air outlet openings are in the immediate door area, that is to say far from the items to be dried. Due to this arrangement of the openings, which is unfavorable in terms of flow technology, the drying air often does not sufficiently flow around the wash ware. Likewise, there can be no optimal mixing between the moist process air and the fresh air in the drying phase. Furthermore, an additional opening in the rinsing tank for the fresh air to be supplied is required. For drying dishes, a long program duration that is not easily shortened is necessary.

Proceeding from a dishwasher of the type mentioned at the outset, the object of the invention is to achieve improved dish drying with a shorter program duration and optimum steam removal from the washing container without visible formation of vapors with little construction effort and minimal space requirements.

The object is achieved according to the invention by the features of claim 1.

Advantageous embodiments of the invention can be found in the subclaims.

Due to the invention, depending on the actual steam and vapor development in the wash cabinet, the correct mixing ratio between the externally supplied fresh air and the moist process air from the wash tank, and vice versa, is automatically set in a selectable volume ratio for drying the dishes, so that the optimally set Volume ratio can advantageously be achieved even shorter drying times. The variable mixing chamber allows maximum suction of the mixed air laden with moisture without any steam or vapor being visible. In addition, the direct connection of the mixing chamber and the fresh air blower in series as well as the avoidance of direct addition of fresh air to the process air in the rinsing tank means that short duct paths can be achieved with little effort without complex valve flap controls. The sucked-in drying air is preferably passed diagonally through the washing container so that a good flow and mixing and thus particularly effective moisture absorption of the drying air takes place on the dishes. The suction of the fan creates a uniform, low vacuum in the washing compartment. As a result, drying air is sucked in controllably through the pressure equalization openings (intended and / or desired leak points) or ventilation points of the washing compartment provided in the rear area of the washing compartment and guided over the dishes. Another advantage is the additional manual adjustment of the wash-chamber ventilation opening. If necessary, the machine operator can influence or set a desired drying condition separately.

• Fig. 1 eine programmgesteuerte Geschirrspülmaschine in der Seitenansicht im Längsschnitt, in schematischer Darstellung,
• Fig. 2 eine im Programmabschnitt Trocknen wirksame Einrichtung aus einer Mischkammer und einem Gebläse zum Entfernen der feuchten Prozeßluft aus dem Spülraum, gemäß Einzelheit "X" in Fig. 1, in vergrößerter Darstellung,
• Fig. 3a die in der Gerätetür angeordnete Mischkammer von der Spülraumseite aus gesehen, in einer von einer Mischkammer-Steuerung veranlaßten ersten Betriebsstellung,
• Fig. 3b die Mischkammer in einer zweiten Betriebsstellung,
• Fig. 3c die Mischkammer in einer dritten Betriebsstellung,
• Fig. 4a die Mischkammer in der Draufsicht in schematischer Darstellung vom Gerätetürinnenraum aus betrachtet, in der Betriebsstellung gemäß Fig 3b,
• Fig. 4b die Strömungsverhältnisse gemäß Betriebsstellung Fig. 3b,
• Fig. 5a die Mischkammer in der Betriebsstellung gemäß Fig. 3c,
• Fig. 5 b die Strömungsverhältnisse gemäß Betriebsstellung Fig. 3c,
• Fig. 6 ein per Hand ohne Werkzeug verstellbares Entlüftungsgitter in der Vorderansicht,
• Fig. 7 eine mit dem Entlüftungsgitter kombinierte verstellbare Entlüftungsblende in der Rückansicht,
• Fig. 8 ein mit einem Werkzeug verstellbares Entlüftungsgitter in der Vorderansicht,
• Fig. 9 die bei dem Entlüftungsgitter gemäß Fig. 8 eingesetzte Entlüftungsblende in der Vorderansicht.

The following description serves to explain the subject matter of the invention, an exemplary embodiment of which is shown in the drawings. Show it:

• 1 shows a program-controlled dishwasher in a side view in longitudinal section, in a schematic representation,
• 2 shows an effective device in the drying program section from a mixing chamber and a blower for removing the moist process air from the wash cabinet, according to detail "X" in FIG. 1, in an enlarged view,
• 3a seen the mixing chamber arranged in the appliance door from the wash cabinet side, in a first operating position caused by a mixing chamber control,
• 3b, the mixing chamber in a second operating position,
• 3c the mixing chamber in a third operating position,
• 4a, the top view of the mixing chamber in a schematic representation from the interior of the appliance door, in the operating position according to FIG. 3b,
• 4b, the flow conditions according to the operating position Fig. 3b,
• 5a, the mixing chamber in the operating position shown in FIG. 3c,
• 5 b the flow conditions according to the operating position Fig. 3c,
• 6 a ventilation grille that can be adjusted by hand without tools in the front view,
• 7 is an adjustable ventilation panel combined with the ventilation grille in the rear view,
• 8 a ventilation grille adjustable with a tool in the front view,
• FIG. 9 shows the ventilation screen used in the ventilation grille according to FIG. 8 in a front view.

1 shows a schematic representation of a program-controlled dishwasher in longitudinal section in side view in FIG. 1, the washing compartment (3) of which can be closed by an appliance door (2) or the washing container with the door closed in the drying program section via a washing compartment vent opening (4 ) or the like. In the appliance door (2) is connected to the ambient air for removing the steam-laden moist air. In the previous water-carrying program sections, pre-rinsing, cleaning, intermediate rinsing and rinsing a rinsing program, this vent opening (4) is preferably completely closed. This controls a mixing chamber (5) connected downstream of the wash chamber ventilation opening (4), into which a separate fresh air duct (6) also opens openly. The mixing chamber (5) is followed by a blower (7) which serves to remove the mixed air from the device.

The fresh air duct (6) formed in the appliance door (2) and the washing area vent (4) are each guided separately and open (Fig. 2) into the mixing chamber (5) connected to the blower (7) on the suction side. The mixing chamber (5) can be adjusted to a changeable mixing ratio between the fresh air supplied via the fresh air duct (6) and the moist air drawn off from the wash cabinet (3) in the sense of a reduction in the fresh air proportion and an increase in the proportion of moist air during the drying of the dishes, the Volume flow of the mixed air remains constant.

So is in the initial phase of drying, in which the moisture content of the process air is significantly higher than at the end of drying dishes over a predetermined period of time, for. B. over about 5 minutes, the volume fraction of the fresh air drawn in via the separate fresh air duct (6) is set to a multiple of the extracted moist air fraction from the wash cabinet (3). As the drying of the dishes progresses, the mixing ratio is preferably continuously changed, so that towards the end of the drying of the dishes, the proportion of moist air or process air extracted from the wash cabinet (3) is a multiple of the proportion of fresh air sucked in via the fresh air duct (6).

By direct connection of the mixing chamber (5) and the fresh air blower (7) in series, short duct paths can be implemented with little effort. In addition, depending on the actual steam and vapor development in the wash cabinet (3), the correct mixing ratio between externally supplied fresh air and the moist process air from the wash cabinet (3) and vice versa can always be preset in a selectable volume ratio for optimal dish drying, which means that optimally set volume ratio, shorter drying times can also be achieved in an advantageous manner. The variable mixing chamber (5) allows maximum suction of the mixed air loaded with moisture without vapors being visible.

The moist or process air supplied from the washing chamber (3) to the mixing chamber (5) is sucked in by the blower (7) via one or more regularly existing pressure equalization openings or ventilation points and sealing points (19) in the washing chamber (3), these desired leak points (19) in relation to the horizontal plane of the washing compartment ventilation opening (4) offset to neighboring ones and / or opposite washroom side walls (20, 21) are arranged. The wash chamber ventilation opening (4) upstream of the mixed air chamber (5) is preferably arranged in the left or right upper area (see FIG. 2) of the appliance door, with at least one pressure compensation opening or ventilation point (vat ventilation) (19) preferably diagonally for this purpose is formed on the opposite rear wall of the wash cabinet (21) in the right or left lower rear wall area or in the side wall of the wash cabinet (20). Advantageously, this is based on the regularly existing vat ventilation (22) z. B. is connected to the fresh water storage bag, not shown, provided outside the rinsing container, used as a leak or pressure compensation opening or ventilation point (19). This deliberate leak is effective in the Rinse program section or when adding fresh water. Other pressure equalization openings or ventilation points that may still be present (possibly also unconscious leaks) can also be used.

Because the drying air in the washing compartment (3) is preferably led diagonally through the washing container, there is a good flow and mixing and thus a particularly effective moisture absorption of the drying air on the dishes (24). In the wash cabinet (3), the running fan (7) creates a uniform, low vacuum which draws air through the tub ventilation (22) and leads specifically over the dishes (24) loaded in the dishes baskets (23).

Depending on the program, the setting or adjustment of the mixing chamber (5) to the correct mixing ratio depending on the progress of the drying of the dishes is initiated by the program switch (not shown) of the dishwasher (1), the mixing chamber (5) being infinitely variable or in stages during predeterminable time intervals during drying (Fig 3a to 3c), preferably in two adjustment stages (II, III). For this purpose, the mixing chamber (5) is assigned a separate mixing chamber control (8) which is connected to the program control of the dishwasher (1) and has an adjusting lever (18) with which the mixed air is regulated.

The mixing chamber control (8) can be designed as a thermal relay, thermal switch (wax switch), bimetal switch or the like. So z. B. one or more such trigger elements are connected in series, if adjustment in several stages is desired. A motor control (servo motor or the like) would, for example, also be able to achieve a continuous adjustment of the mixing chamber (5) to the mixture ratio between the moist air and the fresh air that can be determined by the progress of drying.

The mixing chamber (5) is designed with the downstream fan (7), possibly with the inclusion of the mixing chamber control (8), as a pre-testable installation module (Fig. 2), which is interchangeably arranged in the interior of the appliance door (9).

An advantageous construction of the mixing chamber (5) could be based on the shutter principle. In order to adjust the mixing chamber (5) to the correct mixing ratio of the fresh air to the process air, mutually adjustable closure elements are used, which are assigned to the fresh air duct (6) and the washing chamber ventilation opening (4).

One embodiment is easy to implement (see FIGS. 2, 3a to 3c and 4a, 4b, 5a, 5b), in which two concentrically inserted cylinder tubes (11, 12) that can be rotated relative to one another are provided as closure elements, the outer surfaces of the cylinder surfaces (13 and . 14) and / or their cylinder faces (15 or 16) embody closure diaphragms (17) and passage openings (18) which are opened or closed continuously when the cylinder tubes (11, 12) are turned. The passage openings (18) are opened and closed alternately in such a way that when the fresh air duct (6) is closed, the washing space ventilation is opened by a corresponding amount, and vice versa. For this purpose, the passage openings (18) and the closure panels (17) are located directly in front of the fresh air duct (6) and in front of the wash chamber ventilation opening (4).

The blower (7) connected downstream of the mixing chamber (5) is aligned coaxially with the cylinder tubes (11, 12) in order to achieve a low installation effort and to avoid long channel paths, one of the two cylinder tubes (11, 12) being fixed to the device in the door (2) is fixed and the second cylinder tube (12) rotatably mounted in the fixed tube.

3a shows that position (1) of the mixing chamber (5) in the water-carrying program steps that lies before the drying program section.

In this position (Fig. 3a), the wash cabinet vent (4) is closed and the fresh air duct (6) is opened.

At the beginning of the drying of the dishes or shortly thereafter, the mixing chamber control (8) causes the washing-up space ventilation opening (4) to open slightly (Fig. 3b, 4a, 4b) and the fresh air duct (6) to open completely. This makes sense since the moisture content of the process air is very high in the initial phase of drying. Over a predeterminable period of time based on empirical values or calculated values, e.g. B. over about 5 minutes, the mixing chamber (5) remains in this position. The volume fraction of the fresh air drawn in via the separate fresh air duct (6) is hereby set to a multiple of the extracted moist air fraction from the wash cabinet (3).

As the drying of the dishes progresses, the mixing ratio is changed either continuously or in stages, as shown in FIGS. 3, 4 and 5. In the example of the step-by-step setting shown here, towards the end of drying, the washing-room ventilation opening (4) is completely opened by the mixing chamber (5) (FIGS. 3c and 5a, 5b) and the fresh air duct (6) is almost closed. The proportion of moist air or process air extracted from the wash cabinet (3) is now a multiple of the fresh air drawn in via the fresh air duct (6). 4a and 4b or 5a and 5b, thick and thin arrows indicate the increased fresh air addition or the increased proportion of moist air. The variable mixing chamber (5) enables the drying air, which is optimally adapted to the progress of the drying process, to be sucked out of the drying air loaded with moisture in the correct mixing ratio, the volume flow rate of the mixed air removed from the device remaining constant.

In order to be able to carry out manual readjustment or fine adjustment by the customer, in addition to the automatically controlled mixed air control, in particular with regard to the visibility of the vapor, the wash cabinet ventilation opening (4) is a fixed ventilation grille (27) preferably arranged in the inner door panel (26) of the appliance door (2), see Fig. 2 and 6 to 9, upstream, which vents (28) z. B. in a segment-like arrangement. Behind the fixed ventilation grille (27) or behind the ventilation slots (28) there is an external space, for example by hand (Fig. 6, 7) or with a screwdriver (Fig. 8) in the existing empty space bounded to the rear by the mixing chamber (5) , 9) adjustable ventilation cover (29) with ventilation cutouts (30). By deliberately releasing or covering the ventilation slots (28), a desired moist air flow from the rinsing container can be regulated or influenced separately via the ventilation cutouts (30) independently of the program-dependent mixed air control. The customer has the option of setting any desired drying status. There is also the possibility of a readjustment or readjustment of the process air control depending on the delivery status or the series of a dishwasher produced.

For adjustment by hand, an adjustment pin (31) of the ventilation cover (29) engages through the ventilation slots (28) of the ventilation grille (27) according to FIG. 6. In the setting shown, the ventilation cover (29) partially covers all ventilation slots (28) of the ventilation grille (27) which are arranged in segments, while, according to FIG. 8, the ventilation slots (28) remain uncovered. According to FIG. 8, an aperture adjustment is to be carried out with the screwdriver, for which a screw slot (32) of the ventilation aperture (29) extends through the center of the ventilation grille (27). FIG. 7 shows the ventilation screen (29) combined with the ventilation grille (27) in the rear view. In contrast, the vent panel is shown in FIG. 9 as a single part in the front view. The ventilation panels (29) can be provided on the outer circumference with a slight toothing (33) or the like, which, in cooperation with counter-surfaces of the ventilation grille (27), produce latching positions, as a result of which the respective panel setting is secured. If necessary, fine adjustment of the aperture opening cross-section is possible in very small steps. In addition, an adjustment in larger or smaller adjustment ranges can also take place. Of course, a stepless aperture adjustment could also be implemented. In the examples shown here, only one aperture segment can ever be completely covered. However, a further selection of segments in the ventilation grille or a different arrangement of the ventilation cutouts could also be used to implement further aperture settings.

Claims (20)

Dishwasher with a washroom that can be closed by a door and with a washroom ventilation opening that connects the washroom with the ambient air or the like in the appliance door and a mixing chamber for removing the moist air from the washroom when drying dishes, whereby a separate fresh air duct opens into the mixing chamber and for a blower is provided for the transport of the mixed air,
characterized,
that the mixing chamber (5) can be adjusted to a variable mixing ratio between the fresh air supplied and the moist air extracted from the wash cabinet (3) in the sense of a reduction in the fresh air proportion and an increase in the proportion of moist air during the drying time of the dishes with a constant mixed air volume flow rate. Dishwasher according to claim 1,
characterized,
that in the initial phase of drying over a predeterminable period of time, the volume fraction of the fresh air drawn in via the separate fresh air duct (6) or, at the end of the drying of the dishes, the extracted moisture air fraction from the wash cabinet (3) is in each case a multiple compared to the sucked-in moist air fraction or fresh air fraction. Dishwasher according to claim 1 and 2,
characterized,
that the mixing chamber (5) is adjustable according to a selectable mixing ratio of the volume fractions of the fresh air drawn in and the moist air from the washing compartment (3). Dishwasher according to one or more of claims 1 to 3,
characterized,
that the mixing chamber (5) is continuously or in stages, preferably adjustable according to the shutter principle. Dishwasher according to one or more of claims 1 to 4,
characterized,
that the adjustment of the mixing chamber (5) is controlled depending on the program. Dishwasher according to one or more of claims 1 to 5,
characterized,
that the mixing chamber (5) can be actuated during the drying of dishes from a basic setting stage (I), preferably in two adjustment stages (II, III). Dishwasher according to one or more of claims 1 to 6,
characterized,
that the mixing chamber (5) is assigned a separate mixing chamber control (8) controlled by the device program in the form of a motor drive for stepless adjustment or a single or multi-stage thermal release, such as a wax switch or the like for adjustment according to fixed and / or variable increments. Dishwasher according to one or more of claims 1 to 7,
characterized,
that the mixing chamber (5) in the water-carrying program steps of the washing program preceding the drying program section keeps the washing-chamber ventilation opening (4) closed (FIG. 3a). Dishwasher (1) according to one or more of claims 1 to 8,
characterized,
that the mixing chamber (5) consists of two concentrically nested relatively rotatable cylinder tubes (11, 12) which are provided with mutually adjustable shutters (17) and passage openings (18) in front of the fresh air duct (6) and in front of the wash cabinet -Ventilation opening (4) are each arranged on the outer cylinder jacket (13, 14) and / or on a cylinder end face (15, 16). Dishwasher according to one or more of claims 1 to 9,
characterized,
that a cylinder tube (11) is rotatably connected to the appliance door (2) and the other cylinder tube (12) is rotatably mounted in the fixed tube and has an adjusting lever (18) movable by the mixing chamber control (8). Dishwasher according to one or more of claims 1 to 10,
characterized,
that the blower (7) is connected downstream of the fresh air duct (6) and the flushing space ventilation opening (4) in the appliance door (2), the mixing chamber (5) preferably being arranged between the blower (7) and the flushing space ventilation opening (4) and the separate fresh air duct (6) is guided through the appliance door (2). Dishwasher according to one or more of claims 1 to 11,
characterized,
that the moist or process air supplied from the washing compartment (3) to the mixing chamber (5) is sucked in by the blower (7) via one or more regularly existing pressure equalization openings or ventilation points (19) of the washing compartment (3), the pressure equalization openings or ventilation points (19) offset from the plane of the washroom ventilation opening (4) on adjacent and / or opposite washroom walls (20, 21). Dishwasher according to one or more of claims 1 to 12,
characterized,
that the wash chamber ventilation opening (4) upstream of the mixed air chamber (5) preferably in the left or right upper area of the appliance door (2) and at least one pressure equalization opening or ventilation point (19) preferably diagonally thereto on the opposite rear wall of the wash cabinet (21) in the right or left lower rear wall area or on the wash cabinet side wall (20). Dishwasher according to one or more of claims 1 to 13,
characterized,
that the tub venting (22) (connection to the fresh water storage bag or the like) required in the program section rinsing or when adding fresh water is selected as a pressure compensation opening or aeration and venting point (19). Dishwasher according to one or more of claims 1 to 14,
characterized,
that the fresh air duct (6) and the rinse tank vent are each separate are guided from one another and open into the mixing chamber (5) connected on the suction side to the blower (7), Dishwasher according to one or more of claims 1 to 15,
characterized,
that the mixing chamber (5) in the door interior (9) is exchangeably connected upstream of the fresh air duct (6) and the washing chamber vent opening (4). Dishwasher according to one or more of claims 1 to 16,
characterized,
that the mixing chamber (5) with the downstream blower (7) and optionally with the mixing chamber control (8) is designed as a pre-testable installation module, and that the blower (7) downstream of the mixing chamber (5) is coaxial with the cylinder tubes (11, 12 ) is aligned. Dishwasher according to one or more of claims 1 to 17,
characterized,
that the inlet cross-section of the washing compartment ventilation opening (4) is designed to be adjustable for the moist air. Dishwasher according to claim 18,
characterized,
that the washing chamber ventilation opening (4) in front of the mixing chamber (5) is assigned a fixed ventilation grille (27) with an adjustable ventilation cover (29). Dishwasher according to claim 18 and 19,
characterized,
that the ventilation panel (29) from the inner door side of the appliance door (2) is manually adjustable in steps or continuously.

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