CN114521121A - Warewasher with dirt discharge system - Google Patents

Abstract

A warewasher includes at least one washing system (51, 52), and a soil capture system (70). The dirt capture system has a sump cover filter (20; 20-1, 20-2) configured to separate dirt particles from the sprayed wash liquid flowing back into the wash sump (14; 14-1, 14-2) due to gravity. The dirt capture system includes a dirt collection area (71) disposed at least partially in the wash tank and open upwardly to collect the dirt particles separated from the wash liquid by the tank cover filter. A dirt discharge system fluidly connected to the dirt collection area includes a dirt discharge conduit system (72; 72-1, 72-2) for evacuating the dirt collection area when desired. The dirt collection region includes a pressure equalization system (90) for equalizing a negative pressure locally formed in the dirt collection region when the dirt collection region is evacuated.

Description

Warewasher with dirt discharge system

Technical Field

The present invention relates in particular to a commercial warewash machine for washing dishes or utensils, which is configured as a box-type warewash machine or a conveyor-type warewash machine.

Accordingly, the present invention relates to a warewasher that includes at least one wash zone configured as a recirculation loop. The wash zone configured as a recirculation loop comprises: a nozzle system having at least one washing nozzle for spraying washing liquid onto the washware to be washed; a wash tank for capturing at least a portion of the sprayed wash liquid; and a washing pump for supplying the washing liquid collected in the washing tank to the at least one washing nozzle. In addition, the warewasher includes a dirt capture system associated with the at least one wash zone and having at least one sump cover filter for separating dirt particles from the sprayed wash liquid flowing back into the wash sump due to gravity.

Background

A box-type warewasher is a warewasher that can be manually loaded and unloaded. Box-type warewashers (otherwise known as "batch dishwashers") may be rack-type push-through warewashers (also known as hood-type warewashers) or front-end loaders ("front-end loaders") for washing dishes. The front-end loader may be an in-counter machine, an on-counter machine, or a self-contained warewasher with front-end loading ("self-contained front-end loader").

Warewashers configured as box-type warewashers typically include a treatment chamber for washing the washware. Usually, a washing tank is arranged below the treatment chamber, into which washing tank liquid can flow back from the treatment chamber due to gravity. The washing tank is filled with washing liquid, which is usually water, to which washing liquid cleaning agents can be supplied, where appropriate.

The warewasher configured as a box-type warewasher also includes a washing system having a wash pump, having a line system connected to the wash pump, and having a nozzle system having at least one wash nozzle. The washing liquid contained in the washing tank can be delivered by a washing pump via a line system to at least one washing nozzle and sprayed in the treatment chamber through the at least one washing nozzle onto the washware to be washed. Then, the sprayed washing liquid flows back into the washing tub due to gravity.

In particular, the conveyor warewasher is a long gantry warewasher or a rack conveyor warewasher. Conveyor warewashers are commonly used in the commercial field. In contrast to box-type warewashers, in which the washware to be washed remains stationary in the machine during washing, in a conveyor warewasher, the washware is conveyed through different treatment zones of the conveyor warewasher.

Conveyor warewashers typically include at least one pre-wash zone and at least one main wash zone, which is arranged downstream of the pre-wash zone(s), as seen in the conveying direction of the washware. Downstream of the main wash zone(s), as seen in the conveying direction, there is usually arranged at least one post-wash zone or pre-wash zone and at least one final-wash zone connected downstream of the post-wash zone(s). Washware received directly on the conveyor belt or washware held by the racks, as seen in the conveying direction, generally travels in the conveying direction through the inlet channel, the subsequent pre-wash zone(s), the main wash zone(s), the post-wash zone(s), the final rinse zone(s), and the drying zone into the outlet section.

The wash zones of the conveyor-type warewasher each have associated therewith a wash system which comprises a wash pump and a line system connected thereto (wash line system) by means of which wash liquid is supplied to the nozzle system or to at least one wash nozzle of the nozzle system. The washing liquid supplied to the at least one washing nozzle of the nozzle system is sprayed onto the washware in the respective washing zone of the conveyor warewasher, which washware is being conveyed through the respective washing zone by the conveyor of the conveyor warewasher. Each washing zone has associated therewith a tank in which the liquid sprayed through the washing nozzles is received and/or in which the liquid of the nozzle system for the respective treatment zone is provided.

In the case of the conveyor-type warewashing machines generally known from the prior art, the final rinse liquid in the form of fresh water, which can be pure or mixed with other additives, such as rinse aids, is sprayed onto the washware through the spray nozzles of the final rinse zone. At least a portion of the sprayed final rinse liquid is transferred from zone to zone in a direction opposite the direction of conveyance of the washware through the cascade system.

The sprayed final-rinse liquid is captured in a sump of the post-washing zone (post-washing sump), from which the captured liquid is delivered by a washing pump belonging to the washing system of the post-washing zone to the spray nozzles of the post-washing zone (post-washing nozzles). The washing liquid is rinsed off from the washware in the after-washing zone. The liquid present here flows into the wash tank of at least one main wash zone, which is connected upstream of the post-wash zone, as viewed in the conveying direction of the washware. Here, the liquid is usually supplied with cleaning agent and sprayed onto the washware by means of a pump system (wash pump) of a washing system belonging to the main washing zone through nozzles (wash nozzles) of the main washing zone. Subsequently, if no further main washing zone is provided, the washing liquid flows from the washing tank of the main washing zone into the pre-washing tank of the pre-washing zone. The liquid in the pre-wash tank is sprayed onto the washware by means of a pump system (pre-wash pump) of a washing system belonging to the pre-wash zone through pre-wash nozzles of the pre-wash zone in order to remove coarse impurities from the washware.

Warewashers are usually equipped with a wash pump which supplies the line system of the final rinse zone with the final rinse liquid to be sprayed. This ensures in particular that the volume flow of the final-rinse liquid in the final-rinse zone is almost constant. However, it is also conceivable to conduct the final-rinse liquid to the line system of the final-rinse zone with the line pressure on site (e.g. the pressure of the fresh-water supply). In this last-mentioned case, an actuatable valve can be provided between the line system of the final-rinse zone and the spray nozzle, in order to be able to achieve an intermittent or complete interruption of the supply of final-rinse liquid to the spray nozzle.

Whether the warewasher is configured as a box-type warewasher or as a conveyor-type warewasher, a commercial warewasher for washing dishes therefore typically includes at least one wash zone that is configured as a recirculation loop and that includes: a nozzle system having at least one washing nozzle for spraying washing liquid onto the washware to be washed; a wash tank for capturing at least a portion of the sprayed wash liquid; and a washing pump for supplying the liquid collected in the washing tank to the at least one washing nozzle.

Since the washing zone configured as a recirculation circuit is used for washing the washware, at least a portion of the washing liquid which has been sprayed in this washing zone is guided in the circuit and there is therefore the following risk: due to the permanent circulation of the washing liquid, dirt particles removed from the washware are repeatedly crushed and may therefore no longer be easily separated from the washing liquid by means of filter devices or the like. Accordingly, for a washing zone configured as a recirculation loop, the risk of contamination of the wash liquid in the washing zone with dirt increases with increasing washing time, as a result of which the risk of recontamination of the washware is greater and the washing effect as a whole deteriorates.

This problem occurs in particular in the case of a pre-wash zone or a main wash zone of a dishwasher configured as a conveyor-type dishwasher. Since in a conveyor warewasher the wash liquid used flows in cascade in a direction opposite to the direction of conveyance of the washware to be washed, the soil concentration in the wash liquid in at least one pre-wash zone is greatest compared to the soil concentration of the wash liquid in the remaining treatment zones, since the pre-wash zone is where the most soil occurs.

On the other hand, it is unavoidable that during operation of a dishwasher configured as a conveyor-type dishwasher, a portion of the heavily contaminated washing liquid in the pre-washing zone is "entrained" by the conveyance of the washing ware into at least one main washing zone connected downstream of the pre-washing zone. This makes the wash liquid in the main wash zone more heavily soiled with dirt and, therefore, the washing effect in the main wash zone may also deteriorate.

In order to separate dirt particles introduced into a warewasher from the wash liquid used to wash the washware, it is generally known to use a filter device in the form of a dirt filter basket in which the dirt particles introduced into the warewasher are collected. In the case of a warewasher configured as a box-type warewasher, such a dirt filter basket is typically disposed in the sump of the treatment chamber above the wash tank.

On the other hand, with regard to warewashers configured as conveyor-type warewashers, it is known to equip at least a pre-wash tank (which is associated with a pre-wash zone) and preferably also a main wash tank (which is associated with at least one main wash zone) with a flat filter and a dirt-filtering basket.

During operation of the warewasher (configured as a box-type warewasher or as a conveyor-type warewasher), dirt particles washed off the wash ware by means of the circulating wash water then fall onto the planar filter as a result of gravity. At the flat filter, dirt particles are separated from the washing liquid flowing back into the respective washing tank. The separated dirt particles are then typically screened in a dirt filter basket.

The present invention is based on the following problems: in the solutions known hitherto from the prior art (in which the dirt particles are separated from the circulating washing liquid using a flat filter or dirt filter basket), there is a risk that dirt particles which have accumulated on the flat filter or in the dirt filter basket are comminuted to such an extent as a result of the permanent circulation of the washing liquid and are thus comminuted with increasing washing time until their particle size is no longer covered by the mesh size of the flat filter or dirt filter basket, so that despite the provision of the flat filter or dirt filter basket, the increasing accumulation of dirt particles in the washing liquid with increasing washing time cannot be prevented anymore.

Against this background, document DE 102009048810 a1 has disclosed that at least one washing zone of a dishwasher is equipped with a dirt-catching system which comprises a sump cover filter for separating dirt particles from the sprayed washing liquid which flows back by gravity into the washing sump of the washing zone (configured as a recirculation circuit). The dirt capture systems known from this prior art comprise a dirt collection region in which dirt particles separated from the washing liquid by means of a sump cover filter are collected. The dirt collection area is fluidly connected to the dirt discharge conduit system such that dirt particles collected in the dirt collection area of the dirt capture system can be removed when required by means of the dirt discharge pump.

However, the dirt capture system known from the document DE 102009048810 a1 has disadvantages in practical use, in particular with regard to the dirt-removing capacity actually achieved during operation of the dishwasher. It has been found that in order to empty the dirt collection area, the dirt discharge pump must be operated continuously for a relatively long period of time. During this period of time, the recirculation of the washing liquid in the washing zone should also be interrupted. However, this can result in continuous rinsing or washing operations being affected by conventional soil removal systems. In particular, the soil evacuation system known from DE 102009048810 a1 leads to an extension of the program cycle, which is generally not acceptable to the dishwasher operator, or to a reduction in the number of washware washed by the dishwasher per unit time.

Disclosure of Invention

Starting from the dirt capture system known from DE 102009048810 a1 (at least in principle), the invention is therefore based on the following objects: the soil capture system is further developed such that (in an efficient, but easily implementable manner) on the one hand the risk of recontamination of the washware can be reduced and the washing result can be improved overall, and on the other hand the operation of the washware, in particular the washing capacity, is not adversely affected.

According to the invention, this object is achieved in that, in a dishwasher of the type mentioned in the introduction, a dirt capture system is provided which is associated with at least one washing system of the dishwasher, wherein the dirt capture system has associated therewith a sump cover filter which is configured to separate dirt particles from the sprayed washing liquid which flows back into the washing sump as a result of gravity. As in the case of the dirt capture system known from the document DE 102010063711 a1, the dirt capture system according to the invention comprises a dirt collection area which is at least partially arranged in the washing tank and is open upwards and serves for collecting dirt particles which are separated from the washing liquid by means of the tank cover filter.

In addition, in the solution according to the invention, the dirt discharge system, which is in fluid connection with the dirt collection area, is provided with a dirt discharge conduit system, by means of which the dirt collection area can be emptied when required.

The solution according to the invention is characterized in particular in that the dirt collection area of the dirt capture system has a pressure equalization system associated therewith in order to be able to equalize the negative pressure which is locally formed in the dirt collection area by means of said pressure equalization system when the dirt collection area is emptied.

The advantages obtainable with the solution according to the invention are evident: the dirt collection area has associated therewith a pressure equalization system for equalizing the negative pressure locally formed in the dirt collection area when the dirt collection area is emptied, the length of time required for the process of emptying the dirt collection area, in particular for this purpose, being shortened in comparison with dirt capture systems with dirt collection areas as known from the document DE 102010063711 a 1. It has been recognized here that by means of the pressure equalization system, it is possible not only to reduce or equalize the negative pressure which is locally formed in the dirt collection area, but in addition to this, to form a vortex in the dirt collection area when the dirt collection area is emptied, by means of which vortex the washing liquid laden with dirt particles is rotated in the dirt collection area, and in this way the emptying of the dirt collection area is considerably accelerated.

Thus, during continuous operation of the warewasher, periodic draining of soil can be achieved without having to extend the operating time of the warewasher for this purpose. Thus, not only is the risk of recontamination of the wash ware reduced (since the quality of the wash liquid is optimized for the periodic draining of the soil), but also the capacity of the warewasher is not adversely affected.

There are many possibilities to implement a pressure equalization system. In particular, it is advantageous if the pressure equalization system is at least partially arranged in a side wall of the dirt collection area. In this case, the pressure equalization system can comprise, for example, a flexible wall region which deforms during the emptying process of the dirt collection region into the dirt collection region in order in this way to equalize the negative pressure which builds up locally in the dirt collection region when the dirt collection region is emptied.

Advantageously, however, the pressure equalization system comprises a wall area permeable to washing liquid and preferably impermeable to dirt particles, such as a filter, in particular a fine screen filter. Alternatively, slit-shaped openings or punctiform openings are also conceivable. Preferably, the permeable wall area or filter and/or the slit-like or point-like openings are formed in the side wall of the dirt collection area along the periphery in such a way that a vortex of the washing liquid laden with dirt particles is promoted in the dirt collection area when the dirt collection area is emptied.

In accordance with an embodiment of the warewasher according to the invention, the dirt discharge system comprises a dirt discharge pump, the suction side of which is fluidically connected or can be fluidically connected to the dirt collection area. As an alternative to the dirt discharge pump, it is also conceivable to provide an actuatable valve in the dirt discharge conduit system, so that the dirt collection area can be emptied by gravity when required (in particular when the valve is open). However, the provision of such a dirt evacuation pump is preferred, since the time provided for emptying the dirt collection area can be significantly reduced by using the dirt evacuation pump.

On the other hand, if a dirt discharge pump is used, it must be ensured that substantially only the washing liquid laden with dirt particles and collected in the dirt collection region is actually removed by the dirt discharge pump. For this purpose, according to an embodiment of the invention, it is proposed that the pressure equalization system is arranged in a side wall of the dirt collection area between a connection by means of which the dirt collection area is fluidly connected or can be fluidly connected to the dirt discharge duct system and an opposite upper end region of the dirt collection area. In particular, in this case, the pressure equalization system should be arranged as far as possible in the central or upper region of the dirt collection area. It is particularly effective that the pressure equalization system is arranged in an area of the side wall of the dirt collection area which is above the level of 30% of the length of the dirt collection area measured from the connection to the upper end area of the dirt collection area.

The capacity of the dirt collection area should be at least 0.5l and at most 3.0 l. Preferably, the dirt collection area has a capacity in the range between 1.0l and 2.0 l. This involves a compromise in which both the time required for emptying the dirt collection area and the frequency with which the dirt collection area is subjected to an emptying process are taken into account.

Furthermore, it is proposed according to the invention in particular that the effective diameter of the dirt discharge conduit system and of the suction-side inlet and pressure-side outlet of the dirt discharge pump is larger than the effective diameter of the washing pump used in the warewasher, in particular the effective diameter is at least 5 cm. This also has a positive effect on the time required to empty the dirt collection area.

The provision of a pressure equalisation system makes it possible to empty the dirt collection area in a very short time. In particular, this allows the solution according to the invention to use a dirt discharge pump with a pump capacity of at least 100l per minute, and preferably with a pump capacity of at least 110l per minute.

In particular, the solution according to the invention provides an efficient method for draining dirt particles from a washing liquid, so that a longer service life of the washing liquid can be achieved compared to conventional solutions. In this way, it is possible to use the washing liquid for more washing cycles before it has to be replaced. This saves in particular fresh water, cleaning agent and heating energy.

Preferably, the dirt discharge pump is designed to remove the dirt particles collected in the dirt collection region from the washing zone continuously or at a given time and/or event.

The solution according to the invention thus allows dirt particles collected in at least one washing zone of the warewasher by means of the dirt capture system to also be automatically removed from the warewasher. Such automatic soil removal relieves the personnel operating the warewasher from stress. Furthermore, it is possible to prevent in an effective manner the recirculation of washing liquid in the washing zone from being affected or blocked by an overfilling of the dirt collection area.

Drawings

Exemplary embodiments of the solution according to the invention will be described in more detail below with reference to the accompanying drawings.

In the drawings:

FIG. 1 schematically illustrates a warewasher configured in the form of a conveyor warewasher according to a first embodiment of the invention;

FIG. 2 schematically illustrates a warewasher configured in the form of a conveyor warewasher according to a second embodiment of the present invention;

FIG. 3 schematically illustrates a warewasher configured in the form of a conveyor warewasher according to a third embodiment of the invention; and

fig. 4 schematically illustrates a wash tank of a wash zone of a warewasher configured as a conveyor warewasher or as a box-type warewasher, with an embodiment of a soil capture system.

Detailed Description

Fig. 1 illustrates an example of a conveyor warewasher 50 configured in accordance with the teachings of the present invention in a schematic longitudinal cross-sectional view. The conveyor warewasher 50 according to the illustration in fig. 1 comprises a pre-wash zone 51 and a main wash zone 52, which is arranged downstream of the pre-wash zone 51 (as seen in the conveying direction T of the washware (not shown in fig. 1)). In the conveyor-type warewasher 50 illustrated in fig. 1, as viewed in the conveying direction T, downstream of the main wash zone 52 there is arranged a post-wash or pre-rinse zone 53 and a final-rinse zone 54, which is connected downstream of the post-wash or pre-rinse zone 53. Washware (received directly on the conveyor belt 58 or held by the racks) travels in the conveying direction T through the inlet channel 55, the subsequent pre-wash zone 51, the main wash zone 52, the post-wash zone 53, the final rinse zone 54, and the drying zone 56 into the outlet section 57.

The treatment zones 51, 52, 53, 54 of the conveyor warewasher 50 each have associated therewith a spray nozzle 13-1, 13-2, 13-3, 13-4 through which liquid is sprayed onto the washware being conveyed by the conveyor belt 58 through the respective treatment zone 51, 52, 53, 54. At least the pre-wash zone 51, the main wash zone 52 and the post-wash or pre-rinse zone 53 each have a sump (wash sump 14-1, 14-2, 14-3) associated therewith, in which the sprayed washing liquid is received and/or in which the washing liquid for the spray nozzles 13-1, 13-2, 13-3 of the respective zone 51, 52, 53 is provided.

The pre-wash zone 51, the main wash zone 52 and the post-wash zone 53 of the conveyor warewasher 50 according to the first embodiment of the invention shown in fig. 1 each comprise a wash system 10-1, 10-2, 10, 3. Each washing system 10-1, 10-2, 10-3 comprises: wash pumps 11-1, 11-2, 11-3, line systems 12-1, 12-2, 12-3, which line systems are connected to the wash pumps 11-1, 11-2, 11-3, and spray nozzles 13-1, 13-2, 13-3, which spray nozzles are connected to the line systems 12-1, 12-2, 12-3.

Furthermore, a control device 100 (schematically illustrated in the drawings) is provided for (among other things) actuating the respective washing pump 11-1, 11-2, 11-3 of the washing system 10-1, 10-2, 10-3 in a suitable manner during the washing process in order to at least intermittently supply washing liquid through the associated line system 12-1, 12-2, 12-3 to the spray nozzles 13-1, 13-2, 13-3 of the nozzle system associated with the respective washing system 10-1, 10-2, 10-3.

In the conveyor warewasher 50 illustrated in fig. 1, final rinse liquid in the form of fresh water, which may be mixed with further chemical additives, such as rinse aids, is sprayed onto the washware (not illustrated in fig. 1) through spray nozzles 13-4 of the final rinse zone 54 arranged above and below the conveyor belt 58. As illustrated in fig. 1, laterally arranged spray nozzles 13-5 may also be provided in the final-rinse zone 54.

A portion of the final rinse liquid sprayed in the final rinse zone 54 is conveyed through the cascade system from zone to zone in a direction opposite the conveyance direction T of the washware. The remaining portion of the final rinse liquid is conducted directly to the pre-wash tank 14-1 of the pre-wash zone 51 through valve 59 and bypass line 60.

The final rinse liquid sprayed in the final rinse zone 54 is captured in a sump of the post-wash or pre-rinse zone 53 (post-wash or pre-rinse sump 14-3), from which the captured liquid is delivered to the spray nozzles 13-3 of the post-wash or pre-rinse zone 53 (post-wash or pre-rinse nozzles) by the wash pump 11-3 of the wash system 10-3 belonging to the post-wash or pre-rinse zone 53. The wash liquid is rinsed from the washware in the post-wash or pre-rinse zone 53.

The liquid which here emerges flows into the washing tank 14-2 of the main washing zone 52, is usually supplied with chemical cleaning agent and is sprayed onto the washware by means of the washing pump 11-2 of the washing system 10-2 belonging to the main washing zone 52 through the spray nozzles 13-2 (washing nozzles) of the washing system 10-2 belonging to the main washing zone 52.

The wash liquid then flows from wash tank 14-2 of main wash zone 52 into pre-wash tank 14-1 of pre-wash zone 51. In the pre-washing zone 51, the washing liquid collected in the pre-washing tank 14-1 is sprayed onto the washware by means of the washing pump 11-1 of the washing system 10-1 belonging to the pre-washing zone 51 through the spray nozzles 13-1 (pre-washing nozzles) of the washing system 10-1 belonging to the pre-washing zone 51 in order to remove coarse impurities from the washware.

In the conveyor warewasher 50 shown in FIG. 1, the main wash zone 52 includes a sump cover filter 20-2 disposed above the main wash sump 14-2. During operation of the conveyor warewasher 50, wash liquid is sprayed onto the wash ware through the spray nozzles 13-2 (wash nozzles) of the washing system 10-2. The sprayed wash liquid flows back into the wash tank 14-2 of the main wash zone 52 due to gravity, wherein the dirt particles rinsed from the washware in the main wash zone 52 are retained by the tank cover filter 20-2, provided that they are larger than the mesh size of the tank cover filter 20-2. Preferably, the mesh size of the slot cover filter 20-2 is about 1mm to 4 mm.

In the conveyor warewasher 50 schematically illustrated in fig. 1, for the purpose of cleaning the tank cover filter 20-2, the rinsing operation must be interrupted in order to allow manual cleaning of the tank cover filter 20-2.

A portion of the washing liquid sprayed in the main washing zone 52 enters the washing tank (pre-washing tank 14-1) of the pre-washing zone 51 through an overflow system 61. Like the main wash zone 52, the pre-wash zone 51 is also equipped with a sump cover filter 20-1, which is configured as a planar filter. The sump cover filter 20-1 is arranged above the washing sump (pre-washing sump 14-1) of the pre-washing zone 51 in order to separate dirt particles from the washing liquid which has been sprayed in the pre-washing zone 51 and which flows back into the pre-washing sump 14-1 due to gravity. Preferably, the mesh size of the slot cover filter 20-1 is in the range of between about 1mm and 4 mm.

Since the soil concentration in the wash liquor (as explained in the introduction to the introduction) is greatest in the pre-wash zone 51 (since the pre-wash zone is where the most soil is present), the conveyor warewasher 50 illustrated in fig. 1 is equipped with a soil capture system 70 that is associated with the pre-wash zone 51 and that includes a soil collection area 71-1 disposed in the pre-wash zone 51 and, in particular, within the pre-wash tank 14-1. The construction and function of the soil capture system 70 used in the conveyor warewasher 50 shown in FIG. 1 will be described in more detail below with reference to the illustration in FIG. 4.

In the embodiment of the conveyor warewasher 50 illustrated in FIG. 1, the dirt collection area 71 is used to collect dirt particles separated from the wash liquid by the sump cover filter 20-1. In particular, and as described in more detail below with reference to the illustration in fig. 4, the dirt collection area 71-1 is configured as a chamber, which is arranged in the pre-wash tank 14-1, is open towards the top and comprises a pressure equalization system at its side. Through the upper opening, dirt particles separated by means of the slot-cover filter 20-1 can pass into the chamber-like dirt collection region 71-1. The fact that the dirt collection area 71 comprises a pressure equalization system on the side means that a particularly rapid emptying of the dirt collection area 71 can be achieved.

In particular, and as will be described in more detail below with reference to the illustration in fig. 4, it is preferred that the slot cover filter 20-1 is arranged above the dirt collection area 71-1 and comprises a drainage ramp in the form of a ramp directed towards the feed opening 22, wherein the dirt collection area 71-1, which is configured to be open upwards, is arranged below the feed opening 22 in such a way that dirt particles separated by means of the slot cover filter 20-1 can pass through the feed opening 22 into the dirt collection area 71-1.

Here, it is particularly conceivable for the trough-cover filter 20-1 to be configured at least partially in a funnel-shaped manner, wherein the supply opening 22 is configured inside the funnel-shaped region 21 of the trough-cover filter 20-1 and preferably at the apex of the funnel-shaped region 21 of the trough-cover filter 20-1 (in this respect also in particular with reference to the illustration in fig. 4).

The dirt capture system 70 used in the embodiment illustrated in fig. 1 further comprises a dirt discharge conduit system which is connected to the dirt collection area 71-1, which comprises a vertical conduit 72-1 and a sewer line 73-1, and which is used to discharge dirt particles collected in the dirt collection area 71-1 from the pre-wash zone 51. As shown, the dirt discharge pump 74-1 is disposed in the dirt discharge piping system 72-1, 73-1. The inlet of the dirt discharge pump 74-1 on the suction side is connected to the lower region of the dirt collection area 71-1 via a vertical conduit 72-1 belonging to the dirt discharge conduit system. The outlet of the dirt discharge pump 74-1 on the pressure side leads into a sewage line 73-1 belonging to the dirt discharge pipe system.

In the embodiment illustrated in fig. 1, the sewer line 73-1 leads to an external soil capture container 80, which is arranged outside the pre-washing zone 51 upstream of the inlet channel 55 of the conveyor warewasher 50. Preferably, this external dirt capture container 80 includes a filter, and a connection 81 to a waste water system.

Since when the washing liquid is sprayed in the pre-washing zone 51, it is not possible to prevent a portion of the sprayed washing liquid from entering the soil collection area 71, not only the soil particles separated by means of the sump cover filter 20-1 are delivered out of the pre-washing zone 51 by the soil discharge pump 74-1, but also a portion of the washing liquid is delivered out of the pre-washing zone by the soil discharge pump. The material removed from the dirt collection area 71-1 (dirt particles and wash liquid) is filtered in the dirt capture receptacle 80, wherein the liquid component (wash liquid) can be fed to the waste water system via the outflow connection 81 and the solids (dirt particles) remaining in the dirt capture receptacle 80 can subsequently be disposed of.

As an alternative to the embodiment illustrated in fig. 1, it is also conceivable, as illustrated in fig. 2, to pump dirt particles together with the waste water out of the pre-washing zone 51 into a waste treatment system 82, wherein the system 82 may be positioned in a position directly adjacent to or further away from the conveyor-type warewasher 50. An extrusion system for separating solids from liquids, and/or a comminution system (grinding system, shredding system, etc.) may be used as the waste treatment system 82.

Preferably, the material removed from the dirt collection area 71-1 (dirt particles and wash liquid) is also filtered in the waste disposal system 82, wherein the liquid component (wash liquid) can be fed to the waste water system through the outflow connection 83 and the remaining solids (dirt particles) in the waste disposal system 82 can then be disposed of.

According to an embodiment of the solution of the present invention, it is proposed to feed the material removed from the soil collection area 71-1 (soil particles and wash liquid) to a heat recovery system (heat exchanger) in order to "recover" at least a part of the thermal energy of the material removed from the soil collection area 71-1 and use this at least part of the thermal energy for heating the liquid (wash liquid or eventually rinse liquid) to be sprayed in the warewasher.

For example, it is conceivable that first the material removed from the dirt collection area 71-1 is filtered, wherein subsequently only the liquid component (washing liquid) is supplied to the heat recovery system. In this way, the risk of clogging or malfunction due to dirt particles can be reduced in an efficient manner.

Alternatively or additionally, it is also contemplated that after separating the soil particles from the material removed from the soil collection area 71-1, the liquid component (wash liquid) may be treated in a manner such that the liquid component may be fed back into the washing system of the warewasher. The processing that may be performed may be filtering.

Fig. 3 illustrates an additional embodiment of a conveyor warewasher 50 configured in accordance with the teachings of the present invention. This embodiment is substantially the same as the embodiment described above with reference to the illustration in fig. 1 or fig. 2, but differs in that not only the pre-wash zone 51 is equipped with a soil capture system 70, the construction and function of which will be described in more detail below with reference to the illustration in fig. 4, but also the main wash zone 52.

In contrast to the embodiment illustrated in fig. 1, in the conveyor-type dishwasher 50 illustrated in fig. 3, as a result, a sump cover filter 20-2 comprising a feed opening 22 (see fig. 4) is provided in or above the main wash sump 14-2, wherein an upwardly open configured dirt collection area 71-2 is arranged below the feed opening 22. In said dirt collection area 71-2, dirt particles separated by means of the slot cover filter 20-2 are introduced into the dirt collection area 71-2 through the feed opening 22.

In the embodiment of the solution according to the invention illustrated in fig. 3, at the lower region of the dirt collection area 71-2, there is provided a dirt discharge pipe system comprising a sewer line 73-2 and a vertical pipe 72-2. The material collected in soil collection area 71-2 (wash liquid and separated soil particles) is passed by soil discharge pump 74-2 into a soil capture container 80 formed outside of main wash zone 52 or into a waste treatment system 82 formed outside of conveyor warewasher 50.

The construction and function of the dirt capture system 70 will be described in more detail below with reference to the illustration in FIG. 4.

The soil capture system 70 is disposed within the wash tank 14 of the conveyor warewasher 50 or a warewasher configured as a box-type warewasher. Soil capture system 70 includes a sump cover filter 20, which is preferably disposed in wash sump 14 above the level of wash liquid received in wash sump 14. The sump cover filter 20 serves to separate dirt particles from the washing liquid which has been sprayed and flows back into the washing sump due to gravity. For this reason, the slot cover filter 20 is provided with a suitable mesh size.

A dirt collection area 71 configured as an upwardly open chamber also belongs to the dirt capture system 70. Dirt particles separated by the slot cover filter 20 are fed to the dirt collection area 71 through the opening of the dirt collection area 71 configured as a chamber. For this purpose, it is preferred that the slot cover filter 20 comprises a drainage ramp in the form of a ramp leading towards the feed opening 22, wherein the dirt collection area 71 in an upwardly open configuration is arranged below the feed opening 22.

As shown in fig. 4, in particular a pressure equalization system 90 (which is schematically shown in the figure) is provided in the upper region of the side wall of the dirt collection region 71. In the described embodiment of the soil capture system 70 schematically illustrated in fig. 4, the pressure equalization system 90 is formed by a wall area in the sidewall of the soil collection area 71, which wall area is permeable to wash liquid. In particular, it is conceivable to use a fine filter as a pressure equalization system.

Alternatively or additionally, other openings (in particular slit-shaped openings or punctiform openings) are also conceivable, in particular for promoting the formation of vortices of the washing liquid laden with dirt particles in the dirt collection area 71.

Furthermore, it can be seen in fig. 4 that the pressure equalization system 90 is arranged in an area of the side wall of the dirt collection area 71 above the height of 30% of the length of the dirt collection area 71 measured from the connection 75 to the upper end area 76 of the dirt collection area 71. Due to this arrangement, the following is prevented in an effective manner: during operation of the soil evacuation pump, uncontaminated wash liquid is drawn in through the pressure equalization system 90 (e.g., configured as a fine filter).

As illustrated in fig. 4, it is conceivable, for example, for the trough-cover filter 20 to be configured at least partially in a funnel-shaped manner, wherein the supply opening 22 is arranged inside the funnel-shaped region 21 of the trough-cover filter 20 and preferably in the conical region of the funnel-shaped region 21 of the trough-cover filter 20.

Furthermore, it is preferred that the dirt collection area 71 is configured at the upper end in a funnel-shaped manner (see funnel-shaped area 75 in fig. 4) so as to be able to be inserted into or received inside the supply opening 22 of the channel cover filter 20.

During operation of the dishwasher (not shown in fig. 4), washing liquid is sprayed in the washing zone, wherein a portion of the sprayed washing liquid flows back into the washing tank 14 through the tank cover filter 20. The remainder of the sprayed washing liquid flows directly into the dirt collection area 71 due to gravity through the supply opening 22 provided in the sump cover filter 20. Dirt particles rinsed from the washware during the washing process are prevented by the tank cover filter 20 from entering the wash liquor collected in the wash tank 14 if they are larger than the mesh size of the tank cover filter 20. In fact, dirt particles separated by the trough cover filter 20 move through the drainage ramp to the feed opening 22 and thus into the dirt collection area 71.

In order that the dirt collection area 71 may preferably be emptied automatically, the dirt capture system 70 preferably also comprises a dirt discharge conduit system. In the embodiment of the dirt discharge system illustrated in fig. 4, the dirt discharge conduit system comprises a vertical conduit 72 connected to a lower region of the dirt collection area 71. The vertical pipe 72 is connected to the inlet of the dirt discharge pump 74 on the suction side. The outlet of the dirt discharge pump 74 on the pressure side opens into the sewer line 73, as a result of which the contents of the dirt collection area 71 can be removed from the washing zone when the dirt discharge pump 74 is activated.

The dirt discharge pump 74 is preferably designed to remove the dirt particles collected in the dirt collection area 71 continuously or at given times and/or events together with the wash liquid also collected in the dirt collection area 71. It is particularly conceivable here for the dirt discharge pump 74 to be actuated by the already mentioned control unit 100 as a function of the amount of dirt particles collected in the dirt collection area 71.

However, it is of course conceivable that dirt is pumped out of dirt collection area 71 depending on, for example, the height in dirt collection area 71, the height in sink 14, or other factors.

If a soil capture system 70 is used in the conveyor warewasher 50 (see, e.g., fig. 1-3), it is further contemplated that the soil evacuation pump 74 is activated, for example, based on the conveyance speed at which wash ware is conveyed through the treatment zone of the conveyor warewasher 50, or, for example, based on the amount of final rinse liquid sprayed per unit time in the final rinse zone 54.

The invention is not limited to the embodiments described in connection with the figures.

In this respect, it is for example conceivable that the slot-cover filters 20, 20-1, 20-2 of the dirt capture system 70 do not comprise a substantially centrally arranged supply opening 22 through which dirt particles separated off by means of the slot-cover filters 20, 20-1, 20-2 pass into the dirt collection areas 71, 71-1, 71-2. In fact, the supply opening 22 may also be configured as a gap provided at an edge region of the slot cover filter 20, 20-1, 20-2.

Furthermore, it is basically conceivable for the feed opening 22 to be covered by means of a coarse filter, wherein the mesh size of the coarse filter should preferably be larger than the mesh size of the slot cover filter 20, 20-1, 20-2. The provision of such a coarse filter may prevent, for example, cutlery or other implements (other than dirt particles) from inadvertently entering the dirt collection areas 71, 71-1, 71-2 in an effective manner.

Although the description of the solution according to the invention in fig. 1 to 3 has been given in connection with a conveyor-type warewasher 50, it is of course also conceivable that a warewasher configured as a box-type warewasher is equipped with a soil capture system 70.

Claims (15)

1. A dishwasher, in particular a machine for washing dishes or utensils, with at least one washing system (51, 52) configured as a recirculation loop, the dishwasher being configured as a box-type or conveyor-type dishwasher (50), wherein the at least one washing system (51, 52) comprises: a nozzle system having at least one washing nozzle (13; 13-1, 13-2) for spraying washing liquid onto the washware to be washed; a wash tank (14; 14-1, 14-2) for capturing at least a portion of the sprayed wash liquid; and a washing pump (11; 11-1, 11-2) for supplying washing liquid collected in the washing tank (14; 14-1, 14-2) to the at least one washing nozzle (13; 13-1, 13-2), and wherein a dirt capture system (70) associated with the at least one washing system (51, 52) is additionally provided, wherein the dirt capture system (70) has associated therewith a sump cover filter (20; 20-1, 20-2) configured to separate dirt particles from the sprayed washing liquid flowing back into the washing tank (14; 14-1, 14-2) due to gravity, wherein the dirt capture system (70) comprises a dirt collection area (71) arranged at least partially in the washing tank (14; 14-1, 14-2) and open upwards for collecting the liquid by means of the slot-cover filter (20; 20-1, 20-2) of the dirt particles separated from the washing liquid, and wherein a system of dirt discharge ducts (72; 72-1, 72-2), which dirt discharge system is fluidically connected to the dirt collection area (71), by means of which dirt discharge conduit system the dirt collection area (71) can be emptied when required,

it is characterized in that the preparation method is characterized in that,

the dirt collection area (71) has a pressure equalization system (90) associated therewith for equalizing a locally formed negative pressure in the dirt collection area (71) when the dirt collection area (71) is emptied.

2. The warewasher of claim 1,

wherein the pressure equalization system (90) is at least partially arranged in a side wall of the dirt collection area between a connection (75) by means of which the dirt collection area (71) is fluidly connected or can be fluidly connected to the dirt discharge conduit system (72; 72-1, 72-2) and an opposite upper end area (76) of the dirt collection area (71).

3. The warewasher of claim 2,

wherein the pressure equalization system (90) is arranged in an area of the side wall of the dirt collection area (71) above a height of the dirt collection area (71) of 30% of a length measured from the connection (75) to the upper end area (76) of the dirt collection area (71).

4. Warewasher according to one of claims 1 to 3,

wherein the pressure equalization system (90) comprises a flexible wall region.

5. Warewasher according to one of claims 1 to 4,

wherein the pressure equalization system (90) comprises a wall region permeable to washing liquid, in particular a filter, and preferably a fine filter.

6. Warewasher according to one of claims 1 to 5,

wherein the dirt collection area (71) has a capacity between 0.5l and 3.0l, and preferably a capacity between 1.0l and 2.0l, and wherein the effective diameter of the dirt discharge conduit system (72; 72-1, 72-2) is at least 5 cm.

7. Warewasher according to one of claims 1 to 6, in particular according to claim 6, wherein the soil evacuation system comprises a soil evacuation pump (74); 74-1, 74-2, the suction side of the dirt discharge pump being fluidly connected or fluidly connectable to the dirt collection area (71) and the pressure side of the dirt discharge pump being fluidly connected or fluidly connectable to a dirt capture container (80), wherein the pump capacity of the dirt discharge pump is at least 100l per minute, and preferably at least 110l per minute.

8. Warewasher according to one of claims 1 to 6,

wherein the dirt discharge system comprises at least one actuatable valve arranged in the dirt discharge conduit system (72; 72-1, 72-2) for fluidly connecting the dirt collection area (71) to a dirt capture container (80) when needed or according to a given time and/or event.

9. Warewasher according to one of claims 1 to 8,

wherein the tank cover filter (20; 20-1, 20-2) is arranged above the dirt collection area (71) and comprises a flow-guiding slope in the direction of the feed opening (22), wherein the dirt collection area (71) which is configured to be open upwards is arranged below the feed opening (22) in such a way that the dirt particles separated from the washing liquid by means of the tank cover filter (20; 20-1, 20-2) pass through the feed opening (22) into the dirt collection area (71).

10. The warewasher of claim 9,

wherein the tank cover filter (20; 20-1, 20-2) is at least partially configured in a funnel-shaped manner, and wherein the supply opening (22) is configured inside a funnel-shaped region (21) of the tank cover filter (20; 20-1, 20-2), and preferably in a conical region of the funnel-shaped region (21) of the tank cover filter (20; 20-1, 20-2).

11. Warewasher according to claim 9 or 10,

wherein the supply opening (22) is arranged in the center of the tank cover filter (20; 20-1, 20-2).

12. Warewasher according to one of claims 9 to 11,

wherein a coarse filter is additionally provided, which covers the feed opening (22) at least partially and has a mesh size which is larger than the mesh size of the slot-lid filter (20; 20-1, 20-2).

13. Warewasher according to one of claims 1 to 12,

wherein at least an upper end region of the dirt collection area (71) is configured as a funnel-shaped region (75).

14. Warewasher according to one of claims 1 to 13,

wherein the dirt discharge system comprises a dirt discharge pump (74); (74-1), (74-2), the suction side of the soil evacuation pump being fluidly connected or connectable to the soil collection area (71), and the pressure side of the soil evacuation pump being fluidly connected or connectable to a soil capture receptacle (80), and in particular to a soil capture receptacle (80) provided outside the warewasher, wherein a control unit (100) is additionally provided for actuating the soil evacuation pump (74), in particular depending on the amount of collected soil particles in the soil collection area (71); (74-1) and (74-2).

15. Warewasher according to one of the preceding claims,

wherein the dishwasher is configured as a conveyor-type dishwasher (50), wherein the at least one washing system (51, 52) is configured as at least one washing zone, and wherein, in addition to the at least one washing system (51, 52) configured as a washing zone, the conveyor-type dishwasher (50) comprises at least one final-rinse zone (54) for conveying the washware to be washed past the at least one washing system (51, 52) configured as a washing zone and the final-rinse zone (54), which is connected downstream of the at least one washing system (51, 52) in a conveying direction (T) of the washware, and a conveying device (58); or

Wherein the warewasher is configured as a box-type warewasher and includes a treatment chamber, the washing system (51, 52) being configured within the treatment chamber.

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