FRONT-LOADER DISHWASHING MACHINE WITH HEAT RECOVERY

A dishwashing machine for commercial use is provided, which has a dishwashing chamber with a front door which can be opened for loading and unloading the dishwashing chamber with items to be cleaned. Furthermore, the dishwashing machine has at least one condensation precipitation device, which is connected to the dishwashing chamber and is equipped with at least one fan for sucking and/or blowing vapor and/or air out of the closed dishwashing chamber. The condensation precipitation device also has at least one condensation surface for condensation of vapor. The dishwashing machine additionally has an inlet-air channel for supplying ambient air into the dishwashing chamber. The inlet-air channel is provided with an inlet-air fan.

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Description

This nonprovisional application claims priority to German Patent Application No. DE 102007007133.9, which was filed in Germany on Feb. 13, 2007, and to U.S. Provisional Application No. 60/907,330, which was filed on Mar. 28, 2007, and which are both herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a dishwashing machine for commercial use. Dishwashing machines such as these are used, for example, in large kitchens, in order to clean plates and dishes, glasses, flatware, trays or similar articles.

2. Description of the Background Art

In addition to conveyor-belt transportation and basket transportation dishwashing machines, single-chamber systems are also used in large kitchens, in particular in large kitchens for hotels, guest houses, factory canteens, hospitals, the authorities, schools or similar facilities. Single-chamber systems such as these with a single dishwashing chamber are frequently also referred to as “front-loaders” and have a dishwashing chamber with a front door which can be opened for loading and unloading the dishwashing chamber with items to be cleaned. Dishwashing machines of this type may be designed for various purposes and, for example, may be used as free-standing appliances or else as so-called appliances used below work surfaces.

In contrast to domestic appliances, dishwashing machines for commercial use are subject to the problem that the throughput times must be considerably reduced. While dishwashing programs of up to more than 2 hours are normal for domestic appliances, dishwashing cycles from a few 10 s of seconds up to a few minutes are normal in the field of commercial applications. For this purpose, dishwashing machines for commercial typically have a plurality of tanks so that a final washing liquid is heated (for example in a final washing tank) separately during a washing cycle (for which purpose, for example, a washing tank is used), in order then to carry out a final washing cycle immediately after completion of the washing cycle, or with only a short time delay. After final washing (although a further drying cycle may also be provided), the front door can be opened so that the items that have been cleaned can be removed.

However, one problem with commercial dishwashing machines such as these is that, when the front door is opened, considerable amounts of vapor in. the form of water vapor can escape into the working environment, for example a large kitchen, thus considerably increasing the temperature and the air humidity in this area. This water vapor makes the work of the operator considerably harder. For example, operation of machines such as these by those wearing spectacles is subject to considerable difficulties.

In order to overcome this problem, it is normal practice before unloading the dishwashing machines to wait until the dishwashing chamber has cooled down, in order to reduce the vapor load in the working environment. However, in practice, this procedure is not only associated with the disadvantage of reduced throughput of plates and dishes to be cleaned, but also leads to plates and dishes that have been cleaned and dried being subjected to increased moisture as a result of vapor precipitating on the surfaces of the plates and dishes as they cool down.

By way of example, in order to solve this problem, DE 10 2005 023 428 A1 discloses a commercial dishwashing machine having a spraying chamber for holding items to be cleaned, which has a fan in order to produce an air flow. This air flow is passed from an air inlet underneath the area for the items to be cleaned, for example a gap underneath a folded door of the dishwashing machine, through the spraying chamber to an air outlet, with a deflector device being used. The air flow is then passed to an outlet by the fan.

However, the solution proposed in DE 10 2005 023 428 A1 has the particular disadvantage that the air supply is uncontrolled and is essentially associated with a leak in the form of a gap underneath the front door. However, water vapor, or even liquid, can easily escape through this gap into the working environment during operation of the dishwashing machine. Furthermore, this gap can easily become dirty thus greatly reducing the functionality of the suction process.

In addition, further solutions have been proposed to solve the problem of water vapor formation, in particular once again in the field of small appliances for domestic use. For example, WO 2006/12062 A1 and WO 2006/123947 A1 each disclose small appliances which are provided with vapor suction. However, these appliances have the disadvantage that, in these appliances, the vapor is emitted directly into the working environment.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a dishwashing machine for commercial use which avoids the disadvantages of the dishwashing machines known from the prior art and, in particular, offers a reliable, low-maintenance solution to the problem of water-vapor formation in the working environment.

As described above, the proposed dishwashing machine is designed for commercial use. It is designed to clean many types of item to be cleaned, in particular plates and dishes, flatware, trays, boxes, glasses and/or similar items to be cleaned that are used in large kitchens. However, other types of items to be cleaned may, of course, also be used, for example items to be cleaned from the field of nursing and hospitals.

The dishwashing machine has a dishwashing chamber with a front door which can be opened for loading and unloading the dishwashing chamber with items to be cleaned. This front door will normally have a hinge in order, for example, to allow the front door to be tilted downwards, upwards or to the side, in order in this way to provide access to the dishwashing chamber. Other types of front doors are, however, also feasible. For example, it is possible to provide a combination of a sliding door and folding door. In this case, by way of example, when the lower half of the door is folded down, the upper half can be pushed upwards by means of a linkage.

Furthermore, the dishwashing machine has at least one condensation precipitation device, which is connected to the dishwashing chamber and has at least one fan for sucking or blowing vapor and/or air out of the closed dishwashing chamber. This condensation precipitation device has at least one condensation surface for the condensation of vapor.

In contrast to the prior art, however, the dishwashing machine also has an inlet-air channel for supplying ambient air into the dishwashing chamber. This inlet-air channel is provided with an inlet-air fan.

The refinement according to the invention of the dishwashing machine avoids the disadvantages of the prior art as described above in that ambient air can be introduced into the dishwashing chamber, for example by means of the inlet-air fan, thus ensuring pressure equalization within the dishwashing chamber. The inlet-air channel may, in particular, be designed so as to virtually completely preclude this inlet-air channel from becoming dirty during practical use. The emergence of liquid can also be avoided by appropriate design of this inlet-air channel. By way of example, damage to sensitive items to be cleaned can be avoided by avoiding the problem of a vacuum pressure being formed within the dishwashing chamber.

By way of example, the condensation precipitation device may be accommodated entirely or partially in a top part of the dishwashing chamber, and/or this condensation precipitation device may be accommodated (once again entirely or partially) in a rear wall of the dishwashing chamber.

In order to avoid the pressure equalization problem described above and in order to improve the reliability of the supply of ambient air, the dishwashing machine may, for example, be designed such that the fan and the inlet-air fan are operated synchronized in time. For example, an appropriate controller can be provided for this purpose, synchronizing these fans in time. In particular, this synchronization can be carried out in such a manner that the fan and the inlet-air fan are started at the same time and/or with a predetermined time offset. After the suction process, the inlet-air fan can then be stopped, for example, at the same time as or at a time before the fan. This allows the remaining vapor to be sucked out of the dishwashing chamber.

The at least one inlet-air channel can be in the form of an elongated channel, although it may also be in the form of a connecting stub or short piece of channel. This inlet-air channel can be at least partially arranged in the area of the rear wall of the dishwashing chamber. The inlet-air channel may have an inlet air opening to the working environment on the rear face and/or the top face of the dishwashing chamber. Furthermore, the inlet-air channel may comprise a blowing-in opening in the bottom area of the dishwashing chamber. The combination of these refinements is particularly advantageous since, in this case, an air flow and/or a vapor flow can be produced within the dishwashing chamber, flowing upwards from the bottom area of the dishwashing chamber. In this case, the expression “in the bottom area” should not necessarily be understood as meaning an arrangement in the bottom of the dishwashing chamber itself, but an arrangement in the side walls of the dishwashing chamber is preferable, which is adjacent to the bottom of the dishwashing chamber and/or which is no more than ⅓ to ½ of the overall height of the dishwashing chamber away from the bottom.

In order to prevent water vapor from flowing out through the inlet-air channel, the inlet-air channel may, for example, be equipped with an inlet air valve. This inlet air valve is intended to be designed to switch quickly and to allow large amounts of inlet air to pass through it so that, by way of example, inlet air flaps (for example spring-loaded control flaps) can advantageously be used.

In order to provide further routing for the flow within the dishwashing chamber and to ensure more uniform drying of the items that have been cleaned, flow guiding devices can be provided, in particular in the area of the top of the dishwashing chamber. These flow guiding devices may in particular have flow laminates and/or perforated intermediate covers.

In order to further assist the drying process and to allow pressure equalization as well, the condensation precipitation device may additionally be designed such that at least a portion of the flow of the air which is sucked out of the dishwashing chamber is passed back again into the dishwashing chamber after flowing through the condensation precipitation device (and therefore after at least partial drying).

In particular, the condensation precipitation device may have at least one chamber with at least one inlet and at least one outlet, as well as at least one condensation outflow for emission of condensation. By way of example, this condensation outflow can be passed back again into the dishwashing chamber, into one or more tanks of the dishwashing machine, or the condensation outflow can be connected to an outflow and/or outlet. The fan of the condensation precipitation device may be connected to the inlet and/or to the outlet of the condensation precipitation device, or it may also be provided in the intermediate area, for example at a point within a flow channel of the condensation precipitation device.

In particular, the condensation precipitation device may have at least one cold plate, at least one cold plate which is sprayed with a cooling medium, at least one heat exchanger through which a cooling medium flows (for example a plate-type heat exchanger and/or a serpentine cooling coil-type heat exchanger), or any desired combination of these condenser elements. The at least one condenser element is preferably aligned at an angle to the horizontal. Furthermore, the at least one condenser element may have a laminate arrangement, for example an arrangement of a plurality of cooling surfaces which are arranged essentially parallel. Alternatively or additionally, a meandering arrangement can also be provided, for example by inserting a plurality of cooling surfaces into one another with an offset with respect to one another. This in turn makes it possible to define a flow channel which likewise has a meandering profile. Any desired parallel arrangement of at least two condenser elements is also feasible.

The condensation precipitation device may, for example, have one or more passive condenser elements in the form of cooling surfaces. Alternatively or additionally, the condensation precipitation device may, however, also have at least one condenser element which can be cooled with water, in which case at least one first condenser connection of the condenser element can be connected to a water supply, in particular to a fresh-water supply. In this case, it is particularly advantageous for at least one second condenser connection of the condenser element to be connected to a tank for the dishwashing machine, in particular to a final washing tank. This allows at least a portion of the condensation heat which has been emitted from the vapor to the cooling water to be fed back and reused, in order for example to appropriately heat the final washing liquid.

In particular, the dishwashing machine can be designed in order to carry out a dishwashing program. For example, as mentioned above, the dishwashing machine may for this purpose have one or more controllers, for example an electronic controller, in particular a controller which has one or more computers (for example microcomputers). In particular, this computer can be appropriately programmed to carry out the dishwashing program.

In this case, the condensation precipitation device is intended to be operated in at least one program step in the dishwashing program in order to suck vapor and/or air out of the dishwashing chamber (suction step). For example, this suction program step can be carried out at the end of the dishwashing program. By way of example, as described above, the fan and the inlet-air fan can be operated synchronized in time in order to carry out this suction program step.

In this case, it is particularly advantageous for items to be cleaned which are accommodated in the dishwashing chamber to be finally washed in at least one final washing program step using a final washing liquid from a final washing tank. Cooling water from the condensation precipitation device can then be heated in a. subsequent suction program step by vapor and/or air from the dishwashing chamber, with the heated dishwashing water being passed into the final washing tank. This results in heat being partially recovered, and the time required for subsequent heating of the final dishwashing water can be shortened. This saves energy, and the dishwashing cycle of the dishwashing machine can be shortened further.

In particular, the final washing tank may have a two level control system, for example with the final washing program step being carried out until the level in the final washing tank has reached a lower level. The level in the final washing tank can then be raised again in the subsequent suction program step, until the upper level is reached again. Other program configurations are, however, also feasible.

A liquid valve for controlling a supply of the cooling medium can also be provided when using a liquid-cooled condenser element, in particular a water-cooled condenser element. The dishwashing machine is advantageously designed such that the timings of the operation of this liquid valve and the operation of the fan (and if appropriate the operation of the inlet-air fan as well) are synchronized. In particular, the liquid valve can also be opened and the fan can be started essentially at the same time. The stopping of these two elements can also be synchronized in time, although it is preferable to stop the fan with a certain lag.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 shows a front view of an embodiment of a dishwashing machine according to the invention;

FIG. 2 shows a section illustration in the form of a side view of the embodiment of the dishwashing machine shown in FIG. 1;

FIGS. 3A to 3D show various embodiments of condensation precipitation devices;

FIGS. 4A and 4B show two embodiments of a condenser element with liquid cooling;

FIG. 5 shows an embodiment of a condensation precipitation device with partial feedback of the dried air to the dishwashing chamber; and

FIG. 6 shows an embodiment of a liquid system for one preferred dishwashing machine, illustrated schematically.

DETAILED DESCRIPTION

FIGS. 1 and 2 show an embodiment of a dishwashing machine 110 according to the invention, illustrated schematically. The dishwashing machine 110 is in the form of a front-loader and has a dishwashing chamber 112 with a housing 114. On its front, the housing 114 has a front door 116, which can be folded downward in this embodiment, in order to allow items to be cleaned to be loaded in the dishwashing chamber 112. This loading process can be carried out either directly, by placing items to be cleaned in appropriate holders within the dishwashing chamber 112, or this can be done by the use of baskets for the items to be cleaned. Items to be cleaned and the corresponding devices are not illustrated in FIGS. 1 and 2.

As can be seen in particular from the section illustration in the form of a side view shown in FIG. 2, the dishwashing machine 110 has a cover part 118 which is in the form of a condensation precipitation device 120. Furthermore, this exemplary embodiment of the dishwashing machine has an inlet-air channel 122 in its rear wall (that is to say the side opposite the front door 116). This inlet-air channel has an inlet air opening 124 on the upper face of the dishwashing machine 110. An inlet-air fan 126 is accommodated in the inlet-air channel 122 in the area of this inlet air opening 124. The inlet-air channel 122 opens into the dishwashing chamber 112 at a blowing-in opening 128. This blowing-in opening 128 is in this case arranged in the lower area of the dishwashing chamber 112, that is to say immediately above a liquid level in a washing tank 130 which is accommodated underneath the dishwashing chamber 112. In this embodiment, a spring-loaded inlet air flap 132 is also arranged within the inlet-air channel 122, can be used as a flow valve and makes it more difficult, for example, for water vapor to emerge from the dishwashing chamber 112 into the working environment.

The condensation precipitation device 120 has a chamber 134 with an inlet 136 and an outlet 138. In this case, the outlet is arranged on the upper face of the dishwashing machine 110, although, alternatively or additionally, as is indicated by way of example in FIG. 1, the outlet 138 could also be arranged at the side of the dishwashing machine 110.

In the embodiment illustrated in FIG. 2, a condenser element 140 is arranged within the chamber 134 and, in this simple exemplary embodiment, is a simple cold plate 142 with condensation surfaces 144. The cold plate 142 defines a flow channel 146 within the condensation precipitation device 120. A fan 148 is arranged in the outlet 138, and is preferably operated in synchronism with the inlet-air fan 126, as described above.

Furthermore, the condensation precipitation device 120 has a condensation outflow 150. In this embodiment, condensation can flow directly out of the condensation precipitation device 120 into the washing tank 130 via this condensation outflow 150. Alternatively, an outlet could also be provided into an outflow or, as will be described in more detail further below, condensation could be transferred to a final washing tank.

A flow guiding device 152, for example in the form of a perforated cover plate, is provided substantially immediately underneath the condensation precipitation device 120, in the trough area of the dishwashing chamber 112. This perforated cover plate is used to homogenize air flows within the chamber 112, in order in this way to dry the items that have been cleaned, more uniformly.

The fan 148 of the condensation precipitation device 120 and the inlet-air fan 126 are preferably operated in synchronism, as described above. This allows vapor and/or moist air to be sucked out of the dishwashing chamber 112 into the chamber 134 of the condensation precipitation device 120 without any need for pressure equalization, as a result of leaks in the housing 114 of the dishwashing chamber 112 (for example a gap underneath the front door 116). The condensation precipitation device ensures that moisture is reliably extracted from the air from the dishwashing chamber 112, before it can escape into the working environment.

FIGS. 3A to 3D show various alternative exemplary embodiments of the condensation precipitation device 120 which can be used as alternatives to the exemplary embodiment shown in FIG. 2. It should be noted that, in addition to the condensation precipitation device 120 being formed in the cover part, an analogous configuration on the rear face of the dishwashing chamber 112 (that is to say oriented vertically) is also feasible.

The arrangement in FIG. 3A shows a meandering arrangement of passive cold plates 142, that is to say in this example cold plates 142 which are not liquid-cooled, with condensation surfaces 144. These are arranged at an angle (that is to say at an angle to the horizontal) and thus allow the condensation to flow away to the condensation outflow 150. In addition, a connecting stub of the inlet 136 can additionally be equipped with a rim 154 which extends into, the chamber 134 in order to prevent the condensation from flowing away into the inlet 136. Otherwise, the exemplary embodiment of the condensation precipitation device 120 corresponds essentially to that of the condensation precipitation device 120 in the exemplary embodiment shown in FIG. 2. An outlet air flow 156 flows through the flow channel 146 of the chamber 134 in a meandering form, flowing a number of times over the condensation surfaces 144 of the condenser plates 142. Furthermore, in the exemplary embodiment shown in FIG. 3A, an outflow 158 is provided into which the condensation can run away. As described above, this refinement is also optional.

FIG. 3B shows one exemplary embodiment of a condensation precipitation device 120, whose function and design correspond essentially to those of the example shown in FIG. 3A, but in which the cold plates 142 are sprayed via spraying elements 160 with cooling liquid, for example with cold water. This cooling liquid runs, together with the condensation, away into the condensation outflow 150 and can be supplied either to a waste water connection or, alternatively or additionally, to one or more tanks for the dishwashing machine 110, as well. Spraying the cold plates 142 with cooling liquid therefore represents an intermediate step between a passive configuration of the condenser elements 140 and an active configuration, and increases the efficiency of the precipitation of the condensation in the outlet air flow 156 from which moisture is to be removed.

FIG. 3C shows a further exemplary embodiment, likewise showing a modified form of the condensation precipitation device 120 as illustrated in FIG. 3A. Once again, cold plates 142 are used as the condenser elements 140 and are incorporated in the chamber 134 at an angle to the horizontal (for example at an angle of about 2 to 10°, preferably about 5°, as is also the case in the other exemplary embodiments). In contrast to the exemplary embodiment in FIGS. 3A and 3B, this exemplary embodiment does not have a meandering arrangement, and, instead, the cold plates 142 are in the form of perforated cold plates, each having one or more openings 162 through which the air 156 from which moisture is to be removed can flow from the inlet 136 to the outlet 138. The refinements shown in FIGS. 3A and 3C can, of course, also be combined so that, for example, openings 162 can also be provided in the cold plates 142 in the meandering arrangement shown in FIGS. 3A and 3B.

In contrast to the passive or semi-passive embodiments shown in FIGS. 3A to 3C, active cooling is provided in FIG. 3D. In this case, the condensation precipitation device 120 once again, as in FIGS. 3A to 3C as well, initially has a chamber 134, for example at an angle to the horizontal, with an inlet 136 and an outlet 138, a condensation outflow 150 and a condenser element 140. However, in this case, no passive cooling is provided for the condenser element 140, with cooling being provided via serpentine cooling coils 164, instead. In this case, there are various possible ways to design the condenser element 140, and examples of these are illustrated in FIGS. 4A and 4B.

For example, in the embodiment shown in FIG. 4A, the condenser element 140 is in the form of a pure serpentine cooling coil 164, having a first condenser connection 166 for supplying cooling liquid, and a second condenser connection 168 as the outflow for the cooling liquid. The serpentine cooling coil 164 therefore forms a heat exchanger 170 in which an amount of heat is transferred from the air 156 from which moisture is to be removed to the cooling liquid of the heat exchanger 170.

In contrast, in the embodiment shown in FIG. 4B, the heat exchanger 170 of the condenser element 140 is in the form of a plate-type heat exchanger 172, with flat condensation surfaces 144. Once again, serpentine cooling coils 164 can be provided in the interior of the plate-type heat exchanger 172 and are once again passed, for example in a meandering shape, through the heat exchanger 170, or a cooling medium can flow completely and homogeneously through the plates.

Other types of heat exchangers are also possible as alternatives to the embodiments of the condenser elements 140 illustrated in FIGS. 3D and 4A, 4B. Combinations of the illustrated heat exchangers 170 with other types of condenser elements 140, for example with passive cold plates 142, are also feasible.

In the embodiment of the condensation precipitation device 120 which is illustrated in FIGS. 2 and 3A to 3D, the fan 148 is in each case arranged in the area of the outlet 138. However, this fan 148 can also be designed in an alternative form, for example with the chamber 134 of the condensation precipitation device 120 not being connected directly, but via one or more tubes. In this case, the fan 148 should be designed and configured to ensure that the flow of outlet air 156 through the condensation precipitation device 120 from the dishwashing chamber 112 is as great as possible, with the amount of air in each case being matched to the capability for separation of condensation on the condenser elements 140.

In this case, however, the fan 148 can also be connected to the inlet 136 of the condensation precipitation device 120. Alternatively or additionally, this fan 148 can also be arranged in the flow channel 146 (for example in the meandering configuration shown in FIG. 3A) between the cold plates 142. In order to increase the suction performance, a plurality of fans 148 can also be provided, although this increases the design complexity and the operating costs. In order to overcome this disadvantage, FIG. 5 shows one exemplary embodiment of the condensation precipitation device 120 which not only sucks air out of the dishwashing chamber 112, but passes it over condenser elements 140. In this case, in the illustrated exemplary embodiment, these condenser elements 140 are once again in the form of cold plates 142 although, in this exemplary embodiment, they are arranged vertically rather than horizontally. This would be worthwhile, for example, for an arrangement of the condensation precipitation device 120 on the rear face of the dishwashing machine 110. In an analogous manner, the condensation precipitation device 120 as shown in FIG. 5 may, however, also be designed as a horizontal condensation precipitation device. Alternatively or additionally, in addition to the use of cold plates 142, other refinements are also feasible, for example once again the refinements with heat exchangers 170 as described above.

However, the flow channel 146 splits immediately adjacent to the fan 148 that is incorporated in. the flow channel 146 (with the motor 174 for the fan 148 in this case being arranged outside the chamber 134). While a portion of the air 156 is allowed to escape via the outlet 138 into the working environment, a portion of the flow is once again fed back into the dishwashing chamber 112 via a return line 176, where it assists the pressure equalization ˜process, in order then to be passed back again via the input suction to the inlet 136 of the condensation precipitation device 120. This results in at least a portion of the flow of air 156 passing over the condenser elements 140 repeatedly. In addition to assisting the pressure equalization process, this refinement therefore results in a further reduction in the water vapor escaping into the working environment. The ratio between the flow element that is fed back and the flow element that is ejected may, for example be governed by the opening cross sections of the outlet 138 and the return line 176 and may be adjusted, for example by means of one or more slides and/or valves, in order to achieve optimum drying.

FIG. 6 schematically illustrates one preferred refinement of the dishwashing system in the dishwashing machine 110, including the condensation precipitation device 120. In this case, in this exemplary embodiment, a heat exchanger 170 is provided in the condensation precipitation device 120, and is represented symbolically here in the form of a serpentine cooling coil 164. Air 156 is passed via the heat exchanger 170 through the inlet 136 by means of the fan 148 from the dishwashing chamber 112 (indicated only symbolically here), in order finally to be ejected into the surrounding area via the outlet 138. The inlet-air channel 122, in which the inlet-air fan 126 is arranged, opens into the dishwashing chamber 112 at a blowing-in opening 128. Essentially, reference should be made to the exemplary embodiment shown in FIG. 2 with regard to the possible configuration of the dishwashing chamber 112. The figure does not show a washing tank 130 which, for example, is arranged in the bottom area of the dishwashing chamber 112, or is in the form of a separate tank.

By way of example the heat exchanger 170 can be designed according to one of the embodiments shown in FIGS. 4A and 43. Alternatively however, it is also feasible to use the condensation precipitation device 120 in the “semi-active” embodiment shown in FIG. 33. In this case, a first condenser connection 166 of the heat exchanger 170 is connected to a cold water connection 178. The second condenser connection 168 is in contrast preferably connected via a free outflow 180 (for example via a free-running section) to a final washing tank 182 for the dishwashing machine 110. The inlet flow of fresh water. via the cold water connection 178 into the heat exchanger 170 can be controlled via a liquid valve 184, for example a solenoid valve.

The final washing tank 182 in this exemplary embodiment is preferably in the form of a two-level tank, having an upper level sensor 186 and a lower level sensor 188. The final washing tank 182 is connected via a pump 190 and a pipeline system 192 to a spraying system 194, in order to apply liquid to the items to be cleaned.

Furthermore, the dishwashing machine 110 may have a controller 196 which, for example, can be designed as described above, that is to say in particular may comprise one or more computers, and which is preferably programmed to carry out a dishwashing program. By way of example (not illustrated in FIG. 6), the controller 196 can check information from the level sensors 186, 188, can operate the pump 190 and can operate the liquid valve 184 and the fan 148 and/or 126.

Thus, as already described above, it is possible to carry out a final washing program step first of all, in which (for example following one or more washing steps in which the dishwashing machine 110 is operated in the circulation mode), the plates and dishes in the dishwashing chamber 112 are finally washed using final washing liquid from the final washing tank 182. For example, in this case, the level of the final washing liquid in the final washing tank 182 can fall from the level of the upper level sensor 186 to the level of the lower level sensor 188. When this lower level is reached, the controller 196 preferably automatically stops the pump 190. The liquid valve 184 is preferably closed during this final washing program step.

The fan 148 can then be started in a suction program step, as well as the inlet-air fan 126 (at the same time or preferably with just a slight time offset). Furthermore, the liquid valve 184 can be opened (likewise at the same time or preferably with a slight time offset). During this process, cooling water flows through the heat exchanger 170, and condensation can be precipitated on the heat exchanger 170. At least some of the air 156 which has been sucked out of the dishwashing chamber 112 has the moisture removed from it before it is allowed to escape to the surrounding area again.

“Consumed” cooling water, which has absorbed heat from the vapor from the dishwashing chamber 112 after flowing through the heat exchanger 170, is supplied via the free outflow 180 to the final washing tank 182 until the upper level, as defined by the upper level sensor 186, is reached again. The liquid valve 184 is then closed. The fan 148 (and if appropriate the inlet air fan 126) can be switched off, and the suction program step ended, at the same time as the liquid valve 184 is closed, or a certain lag can preferably be made use of, within which air 156 is still sucked out of the dishwashing chamber 112.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.

Claims

1. A dishwashing machine comprising:

a dishwashing chamber with a front door that is configured to be opened for loading and unloading the dishwashing chamber with items to be cleaned;
at least one condensation precipitation device connected to the dishwashing chamber, the condensation precipitation device having at least one fan for sucking and/or blowing vapor and/or air out of the closed dishwashing chamber, the condensation precipitation device having at least one condensation surface for condensation of vapor; and
an inlet-air channel for supplying ambient air into the dishwashing chamber, the inlet-air channel being provided with an inlet-air fan.

2. The dishwashing machine according to claim 1, wherein the condensation precipitation device is accommodated entirely or partially in a top part of the dishwashing chamber.

3. The dishwashing machine according to claim 1, wherein the condensation precipitation device is accommodated entirely or partially in a rear wall of the dishwashing chamber.

4. The dishwashing machine according to claim 1, wherein the dishwashing machine operates a second fan and the inlet-air fan such that they are synchronized in time to start them at a same time and/or with a predetermined time offset.

5. The dishwashing machine according to claim 4, wherein the dishwashing machine stops the inlet-air fan at the same time as or at a time before the second fan.

6. The dishwashing machine according to claim 1, wherein the inlet-air channel is arranged at least partially in an area of the rear wall of the dishwashing chamber.

7. The dishwashing machine according to claim 1, wherein the inlet-air channel has an inlet air opening to a working environment on the rear face and/or a top face of the dishwashing chamber.

8. The dishwashing machine according to claim 1, wherein the inlet-air channel comprises a blowing-in opening provided in a bottom area of the dishwashing chamber.

9. The dishwashing machine according to claim 1, wherein the inlet-air channel has an inlet air valve and/or an inlet air flap.

10. The dishwashing machine according to claim 1, wherein at least one flow guiding device is provided in a cover area of the dishwashing chamber and is designed to assist flow to pass uniformly through the dishwashing chamber, and wherein the flow guiding device comprises flow laminates and/or a perforated intermediate cover.

11. The dishwashing machine according to claim 1, wherein the condensation precipitation device is designed such that at least a portion of the flow of the air which is sucked out of the dishwashing chamber is passed back again into the dishwashing chamber after flowing through the condensation precipitation device.

12. The dishwashing machine according to claim 1, wherein the condensation precipitation device has at least one chamber with at least one inlet and at least one outlet and at least one condensation outflow.

13. The dishwashing machine according to claim 4, wherein the second fan is connected to the inlet and/or to the outlet.

14. The dishwashing machine according to claim 12, wherein the at least one chamber defines at least one flow channel.

15. The dishwashing machine according to claim 4, wherein the second fan is connected to the flow channel.

16. The dishwashing machine according to claim 1, wherein the condensation precipitation device has at least one condenser elements, the condenser elements including: at least one cold plate; at least one cold plate that is sprayed with a cooling medium; and/or at least one heat exchanger through which a cooling medium flows, in particular a plate-type heat exchanger and/or a serpentine cooling coil-type heat exchanger.

17. The dishwashing machine according to claim 16, wherein the at least one condenser element has at least one of the following arrangements: the at least one condenser element is aligned at an angle to the horizontal; the at least one condenser element has a laminate arrangement; the at least one condenser element has a meandering arrangement; or the at least one condenser element has a parallel arrangement of at least two condenser elements.

18. The dishwashing machine according to claim 1, wherein the condensation precipitation device has at least one condenser element that is cooled with water, wherein the condenser element includes at least one first condenser connection that is connected to a water supply, in particular to a freshwater supply, and wherein the condensation precipitation device includes at least one second condenser connection connected to a tank for the dishwashing machine, in particular to a final washing tank.

19. The dishwashing machine according to claim 1, wherein the dishwashing machine performs a dishwashing program, with the condensation precipitation device being operated in at least one program step in the dishwashing program in order to suck vapor and/or air out of the dishwashing chamber.

20. The dishwashing machine according to claim 19, wherein at least one suction program step is carried out at an end of the dishwashing program.

21. The dishwashing machine according to claim 1, wherein items to be cleaned which are accommodated in the dishwashing chamber are finally washed in at least one final washing program step using a final washing liquid from a final washing tank with cooling water being heated in a subsequent suction program step in the condensation precipitation device by vapor and/or air from the dishwashing chamber and with the heated cooling water being passed into the final washing tank.

22. The dishwashing machine according to claim 21, wherein the final washing tank has a two-level control system, with the final washing program step being carried out until a level in the final washing tank has reached a lower level, and with the subsequent suction program step being carried out until the level in the final washing tank has reached an upper level.

23. The dishwashing machine according to claim 1, wherein at least one liquid valve is provided for controlling a supply of a cooling medium, with the dishwashing machine being designed in order to synchronize the time of the operation of the liquid valve and the operation of the fan.

24. The dishwashing machine according to claim 23, wherein the dishwashing machine is designed such that the liquid valve is opened and a second fan is started substantially at the same time.

Patent History
Publication number: 20090038661
Type: Application
Filed: Feb 13, 2008
Publication Date: Feb 12, 2009
Inventor: Karl HILDENBRAND (Oberkirch)
Application Number: 12/030,761
Classifications
Current U.S. Class: 134/56.0D; Heat-exchange Means External To Work-treating Chamber, Vat Or Zone (134/107)
International Classification: A47L 15/46 (20060101); A47L 15/42 (20060101);