EP2277430A1 - Dishwasher with an optimised filter system - Google Patents

Abstract

The dishwasher has a screening system (20) including a micro screen (28) for filtering fine dirt from a rinsing fluid (S) during operation of a circulation pump. The micro screen includes a screen surface in a range between 18 square cm and 24 square cm. The micro screen is arranged between a circulation chamber (31) and a collection chamber (30). The screening system includes a fine screen (23) arranged upstream of the micro screen based on a component current (US1) of a circulation current (US). The fine screen is arranged concentric to the micro screen.

Description

The present invention relates to a dishwasher, in particular a domestic dishwasher, having a rinsing chamber which can be loaded with a predetermined number of place settings, with a sieve system having a micro sieve for filtering out micro-dirt from a rinsing liquor circulated as circulating flow during operation of a circulating pump, wherein during operation of the circulation pump, the microsieve flows through a first partial flow of the recirculation flow and a second partial flow of the recirculation flow is conducted past the microsieve.

Commercial household dishwashers have a washing chamber, which are equipped with a receiving device for receiving items to be washed. The receiving device may comprise, for example, baskets or the like. The capacity of the washing chamber for items to be washed is in particular structurally predetermined by the internal volume of the washing container and the design of the receiving device.

In domestic dishwashers, the capacity is indicated by the number of place settings, which can be introduced simultaneously with associated serving parts in a washing chamber of the household dishwasher simultaneously. For example, a placemat according to the European standard EN 50242 consists of a dinner plate with a diameter of 26 cm, a soup plate with a diameter of 23 cm, a dessert plate with a diameter of 19 cm, a saucer with a diameter of 14 cm and a cup of 0.2 l capacity 0.25 I glass, 184 mm long fork, 195 mm long soup spoon, 203 mm long knife, 126 mm long teaspoon and one dessert spoon with a length of 156 mm.

For the testing of the capacity of household dishwashers an intended number of place settings and in addition a collection of serving parts is used. With an intended capacity of six or less place settings will be a 32 cm diameter oval plate, a 16 cm diameter serving bowl, a 13 cm diameter serving bowl, two 260 mm long serving spoons, a 192 mm long serving fork and a 175 mm long sauce spoon used. With a planned capacity of seven or more place settings, a 19 cm diameter serving bowl and, instead of the 32 cm diameter oval plate, a 35 cm diameter oval plate is also used.

Commercially available dishwashers have a control device for automatically controlling a sequence of a rinse cycle after a rinse program. In this case, a plurality of washing programs are generally stored in the control device, of which by a user in each case a washing program for performing a rinse cycle is selectable. The different washing programs are adapted to each different requirements, which in particular z. B. from the actually introduced amount of dishes, the type of dishes and the degree of contamination of the dishes can result.

The washing programs usually each include in particular a respective cleaning phase, during which at least temporarily a circulating pump is switched on, which generates a circulation flow from washing liquor, which acts on the washware, in order to detach dirt from the washware and to rinse off it. The rinsing liquor is a disperse system whose main component is water. Depending on the course of the cleaning phase, the wash liquor may comprise detergents, such as surfactants, and dirt from the washware. In order to prevent the dirt contained in the rinsing liquor being applied in the circulation stream back to the items to be washed, a screening system is provided by which the circulation flow from rinsing liquor is guided so that the dirt contained in the rinsing liquor is at least partially retained in the screening system. The screen system is designed so that the retained dirt at a certain time by means of a Abpumpstromes from rinsing liquor, which can be generated by operation of a drain pump can be pumped out of the screen system, ultimately clogging of the screen system by a large amount of dirt to avoid.

A sieve system of a dishwasher has in particular a micro sieve for removing micro-dirt particles from a circulated rinsing liquor. In this case, a first part of the circulating pump conveyed by the circulating pump is guided in a first direction through the microsieve. A second part of the recirculation flow is directed past the microsieve via a bypass. In this way, a high circulation flow can be generated.

In recent years, a need has developed for ever more economical household dishwashers. The reasons for this lie in particular in the fact that prices for electricity and water have risen steadily. In addition, environmental awareness has increased in many parts of the population.

A disadvantage of the known dishwashers is that they no longer meet today's requirements in terms of economy and environmental compatibility.

The object of the present invention is to increase the efficiency of a known dishwasher.

The object is achieved in that the microscreen has a screen area of at least 14 cm ² and at most 28 cm ² , in particular a screen area of at least 16 cm ² and at most 26 cm ² , particularly preferably a screen area of at least 18 cm ² and at most 24 cm ² , has per intended Maßwerkeck.

In the dishwasher according to the invention, the microsieve is dimensioned larger in relation to the intended number of place settings than the corresponding microsieve of a known dishwashing machine. Thus, the microscreen has a screen area of at least 14 cm ² , in particular a screen area of at least 16 cm ² , particularly preferably a screen area of at least 18 cm ² , depending on the intended place setting. In this way, the microsieve can absorb a larger amount of dirt without clogging. As a result, during the execution of the cleaning phase, it is less frequently necessary to pump the retained micro-dirt out of the screening system by means of a pump-off stream of rinsing liquor. The drain pump must therefore during the cleaning phase less often be turned on, so that less total flushing solution is pumped. As a result, the dishwasher also has to be supplied with less fresh water during the cleaning phase. In this way, a considerable reduction of the water consumption of the dishwasher can be achieved.

With a corresponding design of the micro sieve, it is possible, for example, to achieve the same cleaning effect with a wash program whose cleaning phase provides only exactly one cleaning cycle for which a washing program is required in a standard dishwasher whose cleaning phase has a pre-wash and a cleaning cycle. In this case, the dishwasher water consumption during the cleaning phase can typically be halved from 8 liters to 4 liters.

However, it is also possible in many cases, a cleaning effect, to achieve this in a known dishwasher a pre-wash and two cleaning cycles are required to achieve now by a prewash and a single cleaning cycle. In this case, the water consumption drops during the cleaning phase after all by one third, for example from 12 I to 8 I. Generally, it can be stated that in the dishwasher according to the invention while maintaining the cleaning effect rinsing programs are possible whose cleaning phase requires less Teilspülgänge than in a known Dishwasher is the case.

Due to the now possible discontinuation of the pre-wash cycle, a saving of electrical energy can be achieved in addition to the described water saving. Namely, if a rinse is started immediately with a cleaning cycle, the heater of the dishwasher is switched on immediately. This increases the average temperature of the rinse liquor during the cleaning phase compared to a cleaning phase, in which a preliminary rinse with relatively cold water is first carried out. Due to the higher average temperature results in a higher thermal cleaning effect, so that the duration of the cleaning phase can be abbreviated frequently. It is too In many cases it is possible to lower the maximum temperature during the cleaning phase. Both lead to energy savings.

By the intended lower limits or minimum limits for the sieve surface of the microsieve of at least 14 cm ² , in particular of at least 16 cm ² , more preferably of at least 18 cm ² , and by the intended upper limits for the sieve surface of the microsieve of at least 28 cm ² , in particular of not more than 26 cm ² , more preferably of at most 24 cm ² , depending on the intended place setting a small size of the microsieve can be realized, the efficiency increase according to the invention can still be achieved.

According to an expedient development of the invention, the microsieve has passage openings for the wash liquor, which have a cross-sectional area of at least 0.025 mm ² and at most 0.06 mm ² , in particular a cross-sectional area of at least 0.03 mm ² and at most 0.05 mm ² preferably has a cross-sectional area of at least 0.035 mm ² and at most 0.045 mm ² . The proposed lower limits for the cross-sectional area of the passage openings can ensure a sufficiently low flow resistance of the microsieve. At the same time, the proposed upper limits for the cross-sectional area of the passage openings can ensure a sufficient filtering effect of the microsieve.

According to an expedient development of the invention, the proportion of the total area of the through openings of the microsieve on the entire screen surface of the microsieve is at least 25% and at most 50%, preferably at least 30% and at most 45%, more preferably at least 35% and at most 40%. These proposed values provide a favorable ratio of flow resistance and microsieve stability.

According to an expedient development of the invention, the micro-sieve is at least flowed through during operation of a drain pump by a first partial flow of Abpumpstroms, the flow direction of the first partial flow of Abpumpstroms opposite to the flow direction of the first partial flow the recirculation flow runs. In this way, an automatic cleaning of the microsieve can be achieved.

According to an expedient development of the invention, the microsieve between a circulation chamber and a collection chamber is arranged. A circulation chamber is understood to mean a chamber from which the rinsing liquor can be guided to the circulating pump. Thus, for example, a connecting line can be provided, through which the rinsing liquor passes by gravity to the circulation pump. The rinsing liquor purified by the microsieve is therefore immediately available for further circulation. By contrast, a collection chamber is understood to mean a chamber from which rinsing liquor and / or dirt can be pumped out by means of the drainage pump. The proposed arrangement of the microsieve can ensure that the dirt filtered through the microsieve from the rinsing liquor is collected in the collecting chamber and consequently can be removed in a simple manner by switching on the suds pump.

According to an advantageous development of the invention, the sieve system has a fine sieve, which is arranged upstream of the micro sieve relative to the first sub-stream of the circulating stream, the fine sieve having a sieve surface which is at least as large as the sieve surface of the micro sieve.

The use of an additional fine sieve allows pre-cleaning of the recirculation flow. Finer micro-dirt that has passed through the fine screen can then be retained at least partially with the microsieve. As a result of the now two-stage sieve arrangement, the tendency of the micro sieve to become blocked can be further reduced. The proposed dimensioning of the micro-sieve thereby causes a clogging of the micro-sieve is largely prevented even with a large micro-dirt amount.

According to an advantageous development of the invention, the microsieve is an upright microsieve cylinder. The formation of the micro sieve as a stationary microsieve cylinder leads to a good flow through the micro sieve and to a deposition of micro dirt in a lower region of the collection chamber, so that the deposited micro-dirt at best a small part of the sieve surface of the Microsieve can clog. In addition, a compact design of the screen system is possible.

According to an expedient development of the invention, the fine sieve is an upright arranged fine sieve cylinder, which is arranged concentrically to the microsieve cylinder. This results in further advantages in terms of the flow through the two-stage filter assembly and with respect to a space-saving arrangement.

According to an expedient development of the invention, the screening system comprises another, i. second fine sieve, through which during operation of the drain pump the first partial flow of the pumped-off flow and / or during operation of the circulating pump the second partial flow of the circulation flow from the wash chamber is guided into the circulation chamber. The further fine sieve can serve to purify the first partial flow of the pumping off flow during a pumping operation, before it passes from the flushing chamber into the interior of the circulation chamber in order to enter from there through the microscreen and through the optionally existing first fine sieve into the collecting chamber to stream. As a result, the microsieve and the possibly existing, first fine sieve are flowed through in a pumping operation with a pre-cleaned rinsing liquor. In this way it can be prevented that fine dirt accumulates on the microsieve on the side of the circulation chamber, which could not be detached and removed. In addition, the further fine sieve serves to pass the first partial flow of the circulating flow during a circulating operation on the microsieve and possibly on the first fine sieve and thereby to clean it. This allows a higher recirculation flow and yet prevents uncleaned rinse water from entering the recirculation chamber.

According to an expedient development of the invention, the further, second fine sieve is designed as a surface sieve, which is arranged in a bottom of the rinsing chamber. In this way, a large screen area can be realized, which reduces the tendency of the further filter screen to clog.

According to an advantageous development of the invention, the screening system may comprise a coarse screen, through which during operation of the drain pump, a second partial flow of Abpumpstroms and / or during operation of the circulation pump the first partial flow of the circulating flow from the washing chamber is guided into the collecting chamber, wherein the coarse sieve is formed so that objects which are not abpumpbar due to their size by means of Abpumpstromes are retained. The coarse screen may be designed so that larger items such as cutlery, toothpick and the like can not get into the interior of the screen system. As a result, blockage of the screen system is prevented by such objects. Likewise, damage to the microsieve and optionally the fine sieve is prevented. In addition, damage to the drain pump and / or the circulation pump is prevented.

According to an expedient development of the invention, the coarse screen is an upright coarse screen cylinder. This results in further advantages in terms of a compact design of the screening system.

According to a further development of the invention, a fleet storage is provided, which is designed for temporary absorption of rinsing liquor.

By means of such a fleet storage tank, it is possible to store a quantity of rinsing liquor which is not required at a certain time during a rinse cycle. This amount of rinse liquor can then be used at a later time. In this way it can be prevented that a wash liquor, although in principle still usable, has to be pumped out of the dishwasher if it is disturbing at a certain time or is not needed. The reuse of stored rinse liquor leads to a further reduction in the water consumption of the dishwasher.

According to a particularly preferred embodiment of the invention, the fleet storage device for receiving rinsing liquor is provided at the end of an intermediate rinse cycle and / or rinse cycle of a rinse cycle and for dispensing rinse liquor at the beginning of a cleaning phase of a subsequent rinse cycle. In conventional dishwashers, the rinsing liquor is pumped off at the end of an intermediate rinse cycle so as to be able to carry out a subsequent rinse with fresh water. Likewise, at the end of a rinse cycle, the rinsing liquor is completely or partially pumped off, since this during a subsequent drying cycle is not needed. The rinsing liquors of an intermediate rinse cycle or a rinse cycle are generally only slightly soiled. Therefore, such rinsing liquors can be used as a rule in a cleaning phase of a later rinse cycle. The use of the proposed fleet storage means that at the beginning of a cleaning phase of a later rinse less fresh water or no fresh water must be taken. This can bring about a further significant reduction in the water consumption of the dishwasher.

Figur 1

ein Ausführungsbeispiel einer erfindungsgemäßen Haushaltsge- schirrspülmaschine in einer schematischen Seitenansicht,

Figur 2

eine Detailansicht der erfindungsgemäßen Geschirrspülmaschine,

Figur 3

einen zeitlichen Ablauf eines Normalspülgangs bei einer aus dem Stand der Technik bekannten Geschirrspülmaschine, und

Figur 4

einen beispielhaften zeitlichen Ablauf eines Normalspülgangs bei einer erfindungsgemäßen Geschirrspülmaschine.

Other developments of the invention are given in the dependent claims. The invention and its developments are explained below with reference to figures. Each show schematically:

FIG. 1

An embodiment of a Haushaltsge- dishwashing machine according to the invention in a schematic side view,

FIG. 2

a detailed view of the dishwasher according to the invention,

FIG. 3

a time sequence of a normal rinse in a known from the prior art dishwasher, and

FIG. 4

an exemplary time sequence of a normal rinse cycle in a dishwasher according to the invention.

Elements with the same function and mode of action are in the FIGS. 1 4 each provided with the same reference numerals.

FIG. 1 shows an embodiment of a domestic dishwasher according to the invention 1 in a schematic side view, wherein only the essential components for understanding the invention are shown and provided with reference numerals. The dishwasher 1 has a rinsing container 2, which can be closed by a door 3, so that a closed rinsing chamber 4 for rinsing dishes, in particular for rinsing dishes, arises. In FIG. 1 the door 3 is shown in its closed position. The door 3 is swinging about an axis perpendicular to the plane arranged axis can be brought into an open position in which it is aligned substantially horizontally and allows the introduction or removal of dishes.

The dishwasher 1 has an upper dish rack 5 and a lower dish rack 6 for positioning dishes. The upper dish rack 5 is arranged on extension rails or slide rails 7, which are each attached to a side wall of the washing compartment 2. The crockery basket 5 can be moved out of the washing container 2 with the door 3 open by means of the extension rails or slide rails 7, which facilitates the loading and unloading of the upper crockery basket 5. The lower dish rack 6 is arranged in an analogous manner on extension rails or slide rails 8.

The capacity of the dishwasher 1 is specified in particular by the structural design of the washing compartment 2 and the baskets 5, 6. With a width of 60 cm, the dishwasher according to the invention, for example, 12-14 place settings, with a width of 45 cm, for example, 6-7 place settings.

The dishwasher 1 further comprises a supply device 9 for fresh water FW, which is designed so that fresh water supplied from outside FW can reach the interior of the rinsing chamber 4 in a controlled manner. Due to its gravity, the fresh water FW supplied in a controlled manner collects as a rinsing liquor S in a collecting pot 10, which forms a lower part of the washing container 2. The collecting pot 10 is in communication with a circulating pump 11, with the aid of which the rinsing liquor S can be pumped out of the collecting pot 10 via a heater 12 to a water distributor 13 during a circulation phase of a rinsing cycle. Possibly. the heater 12 may be part of the Umwalzpumpen 11, in particular be integrated into this.

The water diverter 13 has three outlets, of which a first is connected to an upper spray arm 14 and a second to a lower spray arm 15. The water switch 13 is controlled so that the funded by the circulation pump 11 rinse water S when rinsing dishes either by one of the spray arms 14, 15 or is conveyed through both spray arms 14, 15 in the washing compartment 2, so as to flush the dishes located there.

The water switch 13 is also controllable so that the pumped by the circulation pump 11 rinse S can be pumped via a third output in a fleet storage tank 16. The fleet memory 16 serves to receive an amount of wash liquor S which is not required at a particular time and, if it is needed again, to deliver it. For the latter, the fleet storage 16 to a controllable output, not shown, via which the stored amount of wash liquor S can be discharged into the washing compartment 2.

In order to be able to remove rinsing water S no longer needed from the washing container 2, a drain pump 17 is provided, which is connected to the collecting pot 10 and a waste water connection device 18. By means of the drain pump 17, it is possible to pump out flushing water S during a pumping down phase of a wash cycle as wastewater AW to the outside. In order to provide the rinse water S with cleaning agents and / or cleaning aids, such as rinse aid, a metering device 19 is further provided.

The collection pot 10 is equipped with a screening system 20, which is designed so that larger parts, such as bones, toothpicks and / or cutlery pieces, which damage the circulation pump 11, the drain pump 17 and / or their inlets and outlets and / or clog could remain in the rinsing chamber 4, even if they have fallen out of one of the baskets 5, 6 and come to rest on the floor 21 of the washing compartment 2. Furthermore, the screen system 20 is designed so that when switched circulating pump 11 guided by the sieve system 20 Umwälzstrom S is cleaned by the S contained in the circulation of rinse S dirt is retained, so as to return the dirt on the items as well as a Pollution of the fleet storage 16 to prevent. Furthermore, the screen system 20 is designed so that the retained dirt can be pumped out by turning on the drain pump 17 via the Abwasseranschlusseinrichtung 18 to the outside.

The dishwasher 1 further has a control device 22 arranged in the region of a control panel of the door 3, which for control purposes with the feed device 9, with the circulation pump 11, with the heater 12, with the water switch 13, with the float storage 16, with the drain pump 17 and the metering device 19 is connected. The control device 22 is designed in particular for automatically controlling a sequence of a rinse cycle after a rinse program. Possibly. can the controller 22 also at another location of the dishwasher such. B. may be provided in the bottom assembly below the washing container 2.

FIG. 2 shows a detailed view of the dishwasher according to the invention the FIG. 1 , In this case, the collecting pot 10 and the screening system 20, which are embedded in the bottom 21 of the washing container, are shown in a sectional view.

The screening system 20 has a first fine screen 23, which is cylindrical, with its axis being upright. The underside of the cylindrical fine sieve 23 rests against the top of the bottom 24 of the collecting pot 10. The cylindrical fine sieve extends up to the top of the sieve system 20.

In the bottom 24 of the collecting pot 10, a connection piece 25 is provided, which via a hose or the like with in the FIG. 1 shown drain pump is connected. The connecting piece 25 is arranged in a region of the bottom 24, which is annularly, in particular substantially annularly surrounded by the Feinsiebzylinder 23. Outside this area, a further connecting piece 26 is formed in the bottom 24, which via a hose, not shown, or a similar means with the in FIG. 1 shown circulating pump is connected.

The fine screen 23 has passages 27 through which wash liquor S can pass. The passage openings are dimensioned such that coarser dirt particles of the washing liquor S are retained. During a circulation operation, in which the circulation pump of the dishwasher is turned on, a recirculation flow US from rinsing liquor, of which a first partial flow US1 from the interior of the cylindrical fine sieve 23 radially outward by the suction of wash liquor S by means of the circulation pump. In this way, at least part of the fine dirt contained in the rinsing liquor is retained in the interior of the cylindrical fine sieve 23. Part of this dirt falls on the bottom 24 of the collecting pot, another part of this dirt adheres to the inside of the cylindrical fine sieve 23. In order to be able to purify the rinsing solution S more thoroughly, a micro-sieve 28 is provided, which likewise has a cylindrical shape and is arranged concentrically around the fine sieve 23. Dirt contained in the first partial flow US1, which can pass through the fine screen 23, is deposited on the inside of the microscreen cylinder 28, since its passage openings 29 are smaller than those of the fine screen 23.

The screen surface of the cylindrical microsieve 28 is designed so that only a much larger amount of dirt leads to clogging of the microsieve 28, as is the case with conventional dishwashers. In this way removal of the retained dirt from the screen system 20 is much less required.

However, a possible removal of the dirt from the screening system 20 takes place in a pumping down phase, in which a pump-off stream AS is generated by switching on the drain pump in order to pump out the flushing liquor S to the outside. A first partial flow AS1 of the pumped down flow AS is guided through the cylindrical microscreen 28 and through the cylindrical fine screen 23, wherein the passage direction of the first partial flow AS1 of the pumping flow AS is opposite to the passage direction of the first partial flow US1 of the circulation flow US, since the first partial flow AS1 of outside, in particular radially, is sucked inwardly through the drain pump 17 in the suction operation. As a result, adhering to the inside of the cylindrical Mikrosiebs 28 and on the inside of the Feinsiebzylinders 23 dirt parts are solved and as well as those dirt particles that lie on the bottom 24 of the collecting pot 10, discharged by means of the Abpumpstromes AS to the outside.

The space enclosed by the microsieve cylinder is also referred to as collection chamber 30. The volume of this collection chamber 30, like the screen surface of the microsieve cylinder 23, is substantially larger than in a conventional one Dishwasher of the same capacity. As a result, the operability of the screen system 20 can be maintained even when a large amount of dirt is introduced by the wash liquor S.

The volume outside the microsieve cylinder 23 in the collection pot 10 is also referred to as the recirculation chamber 31. The circulation chamber 31 is directly connected via a further fine screen 32, which is formed substantially flat, with the above the screen system 20 arranged rinsing chamber. The flat Feinsieb 32 allows the already mentioned first partial flow AS1 of Abpumpstromes AS, from the circulation chamber 31 into the collecting pot 10 from the outside, in particular radially, to penetrate inwardly during the Abpumpbetriebs the drain pump or to flow. The flat fine screen 32 has such passage openings 33 that dirt is prevented as much as possible from entering the circulation chamber 31.

The flat fine sieve 32 further allows a second partial stream US2 of the circulating flow US to be guided directly from the rinsing chamber into the circulation chamber 31. Here, too, the penetration of dirt into the circulation chamber 31 is largely prevented. As a result of the fact that only a first partial flow US1 of the circulatory flow US through the centrally arranged coarse filter 34 through which this concentrically and radially spaced fine filter 27 and through the concentrically arranged microsieve cylinder 28 is passed, a high circulating flow US be generated, which affects the cleaning effect of the dishwasher low. The flat fine sieve 32 is larger than in a comparable previously known dishwashing machine, so that the first partial flow AS1 of Abpumpstromes AS and the second partial flow US2 of the circulating US by foreign bodies, which could deposit on the top of the flat Feinsiebs 32, barely or not at all is impaired. Possibly. In particular, it may be sufficient if the fine sieve 27 is omitted and only the coarse sieve 34 and the micro sieve 28 arranged at a distance around it are provided together with the flat sieve 32.

In order to prevent the penetration of objects into the collection chamber 30, which are not pumpable due to their size, a coarse filter 34 is approximately in Center of the screening system 20 is provided, which has an upper portion 35 and a lower portion 36. The coarse screen 34 is designed as an upright cylinder. Whose upper portion 35 extends into the washing chamber of the dishwasher, so that larger objects, which are washed from the side by rinse S, are retained on the outside thereof. Articles falling directly from above into the inside of the coarse screen cylinder 34 are caught by ribs 37 overlapping in a plan view. Although they are then in the plenum 30, but are prevented by the structure of the coarse screen cylinder 34, with the first part of US1 circulation current US in the direction of Feinsiebs 23 and with a second partial flow AS2 of Abpumpstromes AS in the direction of the drain pump 17 move.

FIG. 3 illustrates the sequence A of a rinse cycle, which is provided in a standard dishwasher for rinsing of normally soiled dishes at maximum load. Shown here is the temperature T of the rinse cycle and the water balance WH of the dishwasher over time t. The sequence A provides in this order a pre-wash cycle VG, a cleaning cycle RG, an intermediate rinse cycle ZG, a rinse cycle KG and a drying cycle TG. Pre-wash cycle VG and cleaning cycle RG form the cleaning phase RP of the rinse cycle.

At the beginning of the pre-wash cycle, a certain amount of fresh water is first taken up by the dishwasher. This is in FIG. 3 illustrated by the fact that the curve WH is above the zero line. This fresh water is circulated as a rinse liquor during the low temperature pre-wash VG. The rinse liquor absorbs dirt which adheres to the items to be rinsed. The rinsing liquor is continuously guided through the sieve system of the dishwasher, so that at least a large part of the dirt is retained there. At the end of the pre-wash cycle, the previous rinse liquor is completely or partially pumped by switching on the drain pump, which is in FIG. 3 is illustrated by the fact that now the curve WH is below the zero line. When pumping the rinsing liquor, the sieve system, as based on the FIG. 2 explained, freed from dirt until the end of the cleaning phase RP.

At the beginning of the next cleaning cycle RG fresh water is added again. Usually, the fresh water is added during the cleaning cycle RG with detergent. The now existing rinsing liquor is circulated so that it is guided through the sieve system during the cleaning cycle. It is heated in a heating phase HRG. The heating phase HRG is terminated when the temperature of the rinsing liquor has reached a predetermined value TRG. Now begins a Nachwaschphase NRG, during which the rinsing liquor is still circulated. At the end of a certain period of time, the Nachwaschphase NRG is completed, pumped out the wash liquor of the cleaning cycle. In the conventional standard dishwashing machine, the screen system is therefore freed twice from dirt during the cleaning phase RP.

At the beginning of the now following intermediate rinse ZG fresh water is again taken, which is then circulated for a predetermined period, so as to remove detergent residues from the items to be washed. At the end of the intermediate rinse cycle ZG, this rinsing liquor is also pumped to the outside. Possibly. this intermediate rinse can also be omitted.

During the rinse cycle KG, fresh water is first added again, which is then heated until an intended temperature TKG is reached. The rinse liquor of the rinse cycle is usually mixed with rinse aid to counteract stains on the cleaned items. The heating of the rinse aid liquor serves the purpose of heating the items to be washed. At the end of the rinse cycle, the rinse liquor is pumped out again.

During the now following drying cycle TG, water adhering to the items to be washed evaporates due to the high temperature of the items to be washed. After a predetermined time then the drying cycle and thus the entire sequence A of the rinse is terminated.

In contrast illustrated FIG. 4 a modified sequence A 'a rinse with a dishwasher according to the invention, with a lower consumption of water and energy at the same load and the same Degree of contamination causes a comparable cleaning effect. The modified cleaning phase RP 'consists exclusively of a cleaning cycle RG'. A prewash is therefore dispensed with. At the beginning of the rinse cycle, rinsing fluid pumped into the float storage tank is introduced into the rinsing chamber in a previous rinse cycle. In this way, it is not necessary to take fresh water at the beginning of the cleaning phase RG '. The curve WH 'therefore runs along the zero line.

The heating phase HRG of the cleaning cycle RG 'is carried out without any special modifications. On the other hand, the subsequent post-washing phase NRG 'is extended compared to the post-washing phase NRG described above. This serves to prevent a reduction in the cleaning effect of the cleaning phase RP 'due to the lack of pre-wash. However, it is not necessary to extend the duration of the Nachwaschphase NRG 'so that the total time duration of the cleaning phase RP' of the total duration of the conventional cleaning phase RP (including pre-wash VG and cleaning RG) corresponds, but is shorter compared to this. The reason for this is that then the average temperature during the cleaning phase RP 'is higher than the average temperature during the cleaning phase RP, which leads to a higher thermal cleaning effect per unit time. Overall, therefore, the circulation time, ie the time in which the circulation pump must be turned on, during the cleaning phase RP 'less than during the cleaning phase RP, resulting in energy savings. Another energy saving results from the fact that the drain pump must be turned on only once during the cleaning phase. Due to the dimensioning of the screening system according to the invention, there are no problems arising from the fact that in the modified cleaning phase RP 'the screening system is only cleaned of dirt once.

At the beginning of the now following intermediate rinse cycle ZG 'new fresh water is recorded as known. However, the rinsing liquor of the modified intermediate rinse ZG 'is not pumped off at the end of the intermediate rinse cycle ZG' but is transported into the fleet storage. This rinsing liquor is then available in a later rinse for a cleaning phase.

Possibly. This intermediate rinsing step can also be omitted. The filling of the fleet storage can then take place at the end of the subsequent rinse step.

The execution of the rinse cycle KG and the drying cycle TG is carried out as before. In comparison of the procedure A of FIG. 3 and the flow A 'of FIG. 4 It is clear that a halving of the water consumption can be achieved by means of a dishwasher according to the invention. While in the example of the FIG. 3 a total of 4 times fresh water must be recorded, is sufficient in the case of the timing A 'the FIG. 4 a 2-time intake of fresh water. If, for example, 4 liters of water have to be taken for each rinse, the result is a saving of a total of 8 liters of fresh water. In addition, due to the shortening of the circulating pump time during the cleaning phase RP ', a considerable amount of electrical energy can be saved without having to accept a worse cleaning result. In addition, the total shortened duration of the rinse in many cases is beneficial.

In summary, it can be stated that the dishwashing machine according to the invention has a "bypass" sieve system which is larger in relation to the loading capacity than in a standard dishwashing machine. As a result, individual partial rinses, for example, a pre-rinse can be omitted, which reduces energy consumption. The occurring reduction in the frequency of cleaning the screen system can be easily overcome by the proposed dimensioning. The "bypass" sieve system of the dishwasher has two liquid streams, one of which is passed through the microsieve and another may be passed through an area sieve. The area of the microsieve is in particular more than 14 cm ² per set place, wherein the passage of the microsieve is preferably between 35% and 45%, and wherein the mesh size of the microsieve can be between 150 μm and 250 μm.

In particular, this sieve system comprises a centrally arranged coarse sieve such as 34, a microsieve arranged at a radial distance therefrom and concentrically around it, such as 28, whereby coarse sieve and microsieve are surrounded on the outside by a surface sieve such as 32. In the exemplary embodiment, the nesting of coarse sieve and micro sieve is positioned approximately centrally in the sieve plane. Coarse screen and microsieve are aligned substantially vertically, while the flat screen is arranged in an approximately horizontal position plane. It has a surface gradient falling from outside to inside on the coarse sieve. In this way, this screen system provides two flow paths for Spülflottenflüssigkeit in the circulation operation of the circulation pump. A first flow path leads through the coarse sieve arranged centrally in a collecting chamber such as, for example, and through the micro sieve surrounding this outside into a circulation chamber, such as, for example,. 31 and from there to the circulation pump. A second flow path leads through the flat screen directly into the circulation chamber, which corresponds to a "bypass", ie a bridging of the series arrangement, in particular concentric nesting arrangement of coarse filter and microfilter.

Possibly. For example, between the coarse sieve and the microsieve, a first fine sieve such as e.g. Be provided 27 whose passages are larger than that of the microsieve and smaller than that of the coarse screen.

The fact that the total area of the sieve system, in particular micro sieve, per place setting is increased compared to the ratios in a conventional standard dishwasher, can in particular eliminate the pre-rinsing and the associated flushing liquor liquid change at the end of the pre-rinse cycle. This saves water and energy. Because it is e.g. In particular, it is no longer necessary to pump dirty rinse liquor liquid after the end of the pre-rinse cycle by means of the rinse pump. Such an enlargement of the sieve surface can ensure sufficient flow through the sieve system during the recirculation process and an impermissible clogging of the respective sieve can be largely avoided.

In order to reduce energy consumption, the screen system is advantageously designed for an amount of dirt that would be required for a larger set of dishes such as 14 place settings in a standard dishwashing during the cleaning phase with prewash and cleaning cycle, as is actually loaded in the dishwasher during operation That is, the dishwasher is operated with a lower number of place settings such as 10 place settings than the number of place settings for which dimensioned the sieve system is. Due to the oversizing, in particular the surface of the sieve system increased by the elimination of the pre-wash and its final Abpumpvorgangs increased contamination during the cleaning phase can be handled properly. Too much clogging of the screen system with dirt, which could affect the circulation flow of Spülflottenflüssigkeit by the circulating pump too much, can be largely avoided. In particular, the surface of the sieve system is oversized so that at least the increased dirt load of the rinsing liquor can be coped with by eliminating the pre-rinsing with final Anpumpvorgang from the sieve system. This optimization of the screen system saves energy. A further reduction of the energy and water consumption of the dishwasher can be achieved by the additional use of a fleet storage.

LIST OF REFERENCE NUMBERS

1

dishwasher

2

rinse tank

3

door

4

rinsing chamber

5

upper dish rack

6

lower crockery basket

7

out rail

8th

out rail

9

Feeding device for fresh water

10

collecting pot

11

circulating pump

12

heater

13

water points

14

upper spray arm

15

lower spray arm

16

fleet memory

17

Drain pump

18

Waste water connection

19

metering

20

screening system

21

Bottom of the washing container

22

control device

23

cylindrical fine sieve

24

Bottom of the collection pot

25

Connecting piece for circulation pump

26

Connecting piece for drain pump

27

Passage openings of the cylindrical fine sieve

28

cylindrical microsieve

29

Passage openings of the cylindrical microsieve

30

plenum

31

circulation chamber

32

flat fine screen

33

Passage openings of the flat fine screen

34

coarse screen

35

upper section

36

lower section

37

ribs

AW

sewage

FW

fresh water

S

rinsing

US

recycle stream

AS

Abpumpstrom

D1

Diameter fine sieve

D2

Diameter microsieve

D3

Diameter coarse sieve

RP

cleaning phase

VG

Voreinigungsgang

RG

cleaning cycle

ZG

intermediate rinsing

KG

rinse cycle

TG

drying cycle

HRG

Heating phase of the cleaning cycle

NRG

Post-wash phase of the cleaning cycle

T

Temperature of the rinse cycle

WH

water Resources

TRG

Maximum temperature of the cleaning cycle

TKG

Maximum temperature of the rinse cycle

Claims (14)

Dishwasher, in particular domestic dishwasher (1), having a rinsing chamber (4) which can be loaded with a predetermined number of place settings, with a sieve system (20) having a micro sieve (28) for filtering out fine dirt from a during a circulation pump operation ( 11) as recirculation flow (US) recirculated rinsing liquor (S), wherein during operation of the circulation pump (11), the microsieve (28) flows through a first partial flow (US1) of the recirculation flow (US) and a second partial flow (US2) of the recirculation flow (US2) is guided past the microsieve (28), characterized in that the microsieve (28) has a sieve area of at least 14 cm ² and at most 28 cm ² , in particular a sieve area of at least 16 cm ² and at most 26 cm ² has a screening surface of at least 18 cm ² and at most 24 cm ² , depending on the intended place setting. Dishwasher according to one of the preceding claims, characterized in that the micro sieve (28) has passage openings (29) for the wash liquor (S), which has a cross-sectional area of at least 0.025 mm ² and at most 0.06 mm ² , in particular a cross-sectional area of at least 0 , 03 mm ² and at most 0.05 mm ² , particularly preferably have a cross-sectional area of at least 0.035 mm ² and at most 0.045 mm ² . Dishwasher according to one of the preceding claims, characterized in that the proportion of the total area of the through openings (29) of the microsieve (28) on the entire screen surface of the microsieve (28) at least 25% and at most 50%, in particular at least 30% and at most 45% , more preferably at least 35% and at most 40%. Dishwasher according to one of the preceding claims, characterized in that the micro-sieve (2) during an operation of a drain pump (17) at least through a first partial flow (AS1) of a Abpumpstroms (AS) flows through, wherein the flow direction of the first partial flow (AS1) of Abpumpstroms (AS) opposite to the flow direction of the first partial flow (US1) of the recirculation flow (US) runs. Dishwasher according to one of the preceding claims, characterized in that the micro sieve (28) between a circulation chamber (31) and a collecting chamber (30) is arranged. Dishwasher according to one of the preceding claims, characterized in that the sieve system (20) has a fine sieve (23) which is located upstream of the micro sieve (28) relative to the first sub-stream (US1) of the recirculation flow (US), the fine sieve (23). 23) has a screen area that is at least as large as the screen area of the microsieve (28). Dishwasher according to claim 6, characterized in that the fine sieve (23) is an upright arranged fine sieve cylinder (23) which is arranged concentrically to the micro sieve cylinder (28). Dishwasher according to one of the preceding claims, characterized in that the micro sieve (28) is an upright microsieve cylinder (28). Dishwasher according to one of the preceding claims, characterized in that the sieve system (20) comprises a further fine sieve (32), through which during operation of the drain pump (17) the first partial flow (AS1) of the pumped out flow (AS) and / or during the Operation of the circulation pump (11), the second partial flow (US2) of the circulation flow (US) from the rinsing chamber (4) into the circulation chamber (31) is guided. Dishwasher according to claim 9, characterized in that the further fine sieve (32) is designed as a surface sieve (32) which is arranged in a bottom (21) of the rinsing chamber (4). Dishwasher according to one of the preceding claims, characterized in that the sieve system (20) comprises a Grobsieb (34), through which during operation of the drain pump (17), a second partial flow (AS2) of Abpumpstroms (AS) and / or during operation the circulating pump (11), the first partial flow (US1) of the circulating flow (US) from the washing chamber (4) is guided into the collecting chamber (30), wherein the coarse sieve (34) is formed so that objects which due to their size by means of Abpumpstroms (AS) are not pumpable, are retained. Dishwashing machine according to claim 11, characterized in that the coarse screen (34) is an upright coarse screen cylinder (34). Dishwasher according to one of the preceding claims, characterized in that a fleet store (16) is provided, which is designed for the temporary absorption of rinsing liquor (S). Dishwasher according to one of the preceding claims, characterized in that the fleet store (16) for receiving rinsing liquor (S) at the end of a Zwischenspülgangs (ZG) and / or a rinse cycle (KG) of a rinse cycle and for delivery of rinsing liquor (S) at the beginning a cleaning phase (RP) of a later rinse is provided.

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