AU2012203276B2

AU2012203276B2 - Dishwasher vented through clearance at door frames

Info

Publication number: AU2012203276B2
Application number: AU2012203276A
Authority: AU
Inventors: Oliver Buschor; Ernst Dober; Ingo Gau; Albert Johann Loichinger
Original assignee: V-Zug AG
Current assignee: V-Zug AG
Priority date: 2011-06-06
Filing date: 2012-06-01
Publication date: 2016-08-18
Anticipated expiration: 2032-06-01
Also published as: EP2371258A3; CN102813494B; EP2371258A2; AU2012203276A1; CN102813494A

Abstract

Abstract During a part of the drying phase the door (2) of the laundry drier is opened by a gap (3). At the 5 same time, a first airflow (11) is fed through the tub (1), while a second air flow (12) is led along the out side of the tub (1). The two airflows are mixed in the region of the gap '(3). In this manner, the drying effi ciency can be increased, the temperature in the rinsing 10 phase can be decreased, and condensation at the gap is reduced. 13, Fig. 1

Description

The invention relates to a dishwasher having a tub for receiving dishes, a control unit: for controlling a cleaning process and. door opening drive for opening the door at least cartiaily· The control unit of the device is adapted to clean the dishes during a cleaning phase using water and to thereafter dry them in a drying phase. Further, the control unit is adapted to open the door by means of the door opening drive during at least part of the drying phase to form a clearance or gap and to generate an air flow at the gap for carrying off vapour during at least part of the drying pnase. ,¾ dishwasher of this type is described in WO 2008/101597. The device is designed to automatically open the door to form a gap while drying the dishes. At the same time, an air flow is generated, which flows along an outer wall of the tub towards the gap·., 'where it. in particular, warms up the bottom side of a. working plate arranged above the device, by means of which the risk of condensation of humidity can be decreased at that location.

It is desirable that embodiments' of the invention provide a dishwasher and a method of this type that has improved drying efficiency.

According to a first aspect of the present invention, there is provided a dishwasher having a tub for receiving dishes, a door for closing the tub, a control unit for controlling a cleaning process, and a door opening drive for at least partially opening the door, wherein the control unit is adapted to clean the dishes during a cleaning phase using water and thereafter to dry them: in a drying phase, and wherein the control unit is further adapted to open the door, by a gap, by means of the door opening drive during at least a part of the drying phase and to generate an air flow· at the gap by means of a fan assembly for carrying off vapour, and wherein at least one opening is arranged at the tub and that, by means of the fan assembly a first air flow can be generated through the opening, the tub and the gap, wherein, by means of the fan assembly, a second air flow can be generated along an outer side of at least a wall of the tub to the gap, and wherein the second airflow does not extend through the tub.

According to a second aspect of the present invention, there is provided a method for operating the dishwasher as described above comprising the following steps: cleaning, in a cleaning phase, the dishes in the tub by means of water, drying, in a drying phase after the cleaning phase, the dishes in the tub, wherein, during the drying phase, a door opening drive is operated in order to open the door to form a gap during at least part of the drying phase, wherein a first air flow is generated at the gap by means of a fan assembly for carrying off vapour, and wherein the first air flow extends from the fan assembly through the tub to the gap.

By means of this first air flow, humidity can be carried off from the tub efficiently and in controlled manner.

Advantageously, the fan assembly allows to also generate a second air flow, which runs along the outer side of at least one wall of the tub towards the gap, but not through the tub. This measure has the advantage that, by mixing the two air flows at the gap, a comparatively dry air flow can be generated at all times, in order to prevent condensation in this region, even if, during some parts of the drying phase, the first air flow exiting from the tub is comparatively humid. In addition, the walls of the tub are cooled by the second air flow such that they are colder than the dishes whereby the drying process is improved further.

Advantageously, in this case, the fan assembly is designed such that, by means of it, air can be fed into the first and the second air flow at the same time. The flow ratio (i.e. the ratio of the average volume flows) of the first and the second air flow can be changed by the control unit. Thus, the control unit can adapt the ratio to the current process parameters .

The control unit can, in particular, be designed to feed, during a first venting phase, a smaller fraction of the air from the fan assembly through the tub than in a second, later venting phase. In other words, the fraction of the air fed from the fan assembly through the tub increases during the drying process. This accounts for the fact that, while the dishes are still very wet, only a small amount of air should be fed through the tub in order to avoid very humid air from exiting at the gap. In order to not get too close to the dew point and to have a defined distance from the dew point, the condensation rate is decreased by lowering the temperature of the rinsing phase, advantageously to at most 50 °C, in particular at most 40°C.

The invention will now be described, by way of nonlimiting example only, with reference to the accompanying figure, which shows a sectional view of the dishwasher.

The dishwasher of Fig. 1 comprises a tub 1 for receiving the dishes. At. its front side (i.e. at the side facing the user) tub 1 is closed by a door 2. Door 2 can be pivoted about a pivoting axis in the region of its bottom edge. Fig, 1 shows door 2 in a slightly opened position in which a gap 3 is formed at its upper edge, A door openixxg drive 4 caxx move door 2 from its closed (vertical) position at least into the slightly open position shown in Fig. 1. Door opening drive 4 is controlled by a control unit (not shown} of the appliance.

Further, the appliance comprises a fan assembly, which, in the shown embodiment, comprises a fan 6 and a switching device 7 arranged after fan 6, Fan 6 is e.g. located at a back side of the appliance below tub 1. It aspirates air from the environment, advantageously through a base section 8 of the. appliance, and. feeds the same towards the back side of tub 1, The aspirated air can be room air or air from a neighbouring appliance space of the kitchen or air from the base of the appliance. The air from faxx 6 arrives at a switching device 7, which splits it with variable ratio into a first air flow 11 and a second air flow 12. The ratio can be controlled by the·control unit of the appliance. In Fig. 1, switching device 7 is only shown schematically and it can e.g. consist of a controllable flap, a valve or a throttle member, which can be pivoted into the path of second air flow 12 by a larger or smaller degree.

First air flow 11 enters tub 1 through an opening 13 arranged in the wall of the tub, crosses the tub, and leaves it through gap 3 of the partially opened door 2.

Second air flow 12 does not run through tub 1, but rather along the back wall (and/or along at least another outer wall) of tub 1 and leaves the niche of the appliance through gap 3 above and laterally to the door. Advantageously, an air guide is provided for this purpose, which is e.g. designed as a duct or hood extending over or around tub 1.

Both air flows 11, 12 can, in addition, leave the niche of the appliance in part through gaps extending laterally along the partially opened door 2.

In the region of gap 3 the air flows 11, 12 are mixed, such that condensation at gap 3 (laterally thereof as well as above, in particular in it supper half) and in particular at the working plate 10 located above gap 3, is reduced or eliminated even if the air exiting from tab 1 is very humid.

The operation of the appliance is controlled by its control unit. In at least one operating mode, e.g. selected by the user, a method is used as it is described in the following.

First, the dishes in tub 1 are cleaned in conventional manner, in a cleaning phase, by means of water and detergent while door 2 is closed. The cleaning phase can be followed by an intermediate watering phase with fresh water. Now follows a final rinsing phase, during which the dishes are rinsed with fresh water and a sparkling detergent. In this phase the dishes can be heated up again by heating the rinsing water, such that the drying in the subsequent drying phase can be improved. The technique requires, however, only a comparatively low temperature during the. final rinsing pha.se, e.g, of at most. 500C, in particular at moat 4D°C (rinsing water temperature), The lower water temperature leads to a reduction in condensate at the gap during the later drying phase* At. the end of the rinsing phase, the water is pumped off.

The rinsing phase is followed by the drying phase. Advantageously, the latter consists of a first and a second section, with door 2 remaining closed during the first section..

During the first section, fan assembly 6, 7 feeds air into second air flow 12 (but not into first air flow 11) along at least one wall of tub 2 such that the same is cooled, down in known manner and water condensates at its inner side.

Between the first arid the second section, door 2 is partially opened such that gap 3 forms. Gap 3 has a width that is, advantageously, between 1 and 10: cm.

During the second section, fan assembly 6, 7 feeds at least part of the air into first air flow 11. Advantageously and after opening door 2, in a first venting phase of the second section, a comparatively small fraction of the air is led through tub 1, while a -comparatively large amount of .air is fed into second, air flow' 1.2. In this manner it can be; made sure that the humidity of the overall air exiting through gap 3 is •not too high even if, at the beginning, the humidity -of first air: flow 11 exiting from tub X is considerable. In a later, second venting phase of the second section of the drying phase, the fraction of the air fed through, tub 1 is larger, 'while the air in second airflow 12 is reduced. Thus, the drying efficiency remains high even when the dishes become dryer.

The duration of the first section of the drying phase (i.e. the section where door 2 is closed) is e.g. between 10 - 35 minutes, in particular between 20 -25 minutes. The second section (i.e. the section where door 2 is partially open) lasts at least 10 minutes.

Notes :

The operating mode for drying with partially opened door can be switched on and off by the user.

The appliance can further be equipped with a humidity and/or temperature sensor by means of which the relative environmental humidity (i.e. the humidity in the space where the appliance is located) or the humidity at gap 3 can be measured or estimated. If this environmental humidity is high, the time for opening door 2 can be selected automatically to be later, and/or the flow in first air flow 11 can be reduced as in contrast to second air flow 12. If the humidity is very high, door 2 remains closed even during the whole drying process and/or no air flows through first air flow 11. In other words, the control unit of the appliance can be designed such that the time for opening door 2 depends on the signal of the humidity sensor.

In the above embodiment, the amount ratio between the first and second airflow is defined by switching device 7. It is also possible to define the amount ratio at least partially by slowly increasing the width of gap 3 by means of opening drive 4 (i.e. continuously or in several steps) during the second section of the drying phase, such that the air resistance for first air flow 11 decreases slowly. In this case the switching device of the appliance is formed at least partially by the control unit, and it is designed to change the width of gap 3 continuously or in several steps by means of door opening drive 4.

To generate the first and second air flow, the fan assembly can also comprise two separate fans.

While, in the present application, advantageous embodiments of the invention are described, it is to be pointed out that the invention is not limited thereto and can also be carried out in different manner within the scope of the following claims.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference numerals in the following claims do not in any way limit the scope of the respective claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS;

1. A dishwasher having a tub for receiving dishes, a door for closing the tub,. a control unit for controlling a cleaning process, and a door opening drive for at least partially opening the door, wherein the control nn.it is adapted to clean the dishes during a cleaning phase using water and thereafter to dry them in a drying phase, and wherein the control unit is further adapted to open the door, by a gap, by means of the door opening drive during at least a part of the drying phase arid to generate an air flow at the gap by means of a fan assembly for carrying off vapour, and wherein at least one opening is arranged at the tub and that, by means of the fan assembly a first air flow can be generated through the opening, the tub and the gap, wherein, by means of the fan assembly, a second air flow can be generated along an outer side of at least a wall of the tub to the gap, and wherein the second airflow does not extend through the tub,
2. The dishwasher of claim 1 wherein the fan assembly is arranged such that it aspires environmental air,
3. The dishwasher of either one of the preceding claims, wherein an air gui.de is provided for guiding the second air flow,
4. The dishwasher of claim 3, wherein the air guide is a channel or hood.
5. The dishwasher of any one of the preceding claims,. .^l-ierein, by means of the fan assembly air can be fed to the and the second air flow at the same time, wherein a ^rnount ratio of the first and the second air flow can by varied ργ the control nn.lt,
6. The dishwasher of claim S, wherein the control ,,ri.it is adapted to feed a smaller amount of air from the fan gjssembly through the tub during a first venting phase of the prying phase than during a second, later venting phase.
7. The dishwasher of either one of claims S and © ^-herein the fan assembly comprises a fan with a subsequent pitching device, wherein, by means; of the switching device air ££om the fan can be fed with a variable amount ratio into the £irst and the second air flow.
8. The dishwasher of. claim 7, wherein the switching ^Vice- is designed to vary a width of the gap continuously or .: ji several steps by means of the door' opening drive.
9. The dishwasher of any one of the preceding -claims herein the control unit is adapted to keep the door closed in * first section- of the drying phase and to open it partially in ^rder to fox® the gap during a second section or, the crying pliase .
10. The dishwasher of any one of the preceding claims comprising a humidity sensor for measuring an environmental humidity and/or a humidity at the gap, wherein the control unit is adapted to determine a time for opening the door and/or a flow through the first air flow as a function of a signal from the humidity sensor.
11. The dishwasher of any one of the preceding claims wherein said first, airflow enters the tub througn said opening and exits the tub through said gap.
12. A method for operating the dishwasher of any of the .preceding claims comprising the following steps; cleaning, in a cleaning phase, the dishes in the tub by means of water, drying, in a drying phase after the cleaning phase, the dishes in the tub, wherein, during the drying phase, a door opening drive is operated in order to open the door to form a gap during at least part of the drying phase, wherein a first air flow is generated at the gap by means of a fan assembly for carrying off vapour, and wherein the first air flow extends from the fan assembly through the tub to the gap.
13. The method of claim 12 wherein, during a first section of the drying phase, the door is kept closed: and, during a second section of the drying phase, the door is partially opened for forming the gap, wherein a duration of the first section, is 10 - 35 minutes and a duration of the second section, is at least id: minutes,
14. The method of claim 13, wherein the duration of the first section is 20 ~ 25 minutes,
15 . The: method of any of the claims 12 ho 14, wherein, before the drying phase, a. rinsing phase is carried out, 'wherein a 'water temperature in. the rinsing phase is at most S0°"C.
16. The method of claim 15, wherein the water temperature in the rinsing phase is at most 40°C.