A DISHWASHER

Description

[0001] The present invention relates to dishwashers wherein a program including the regeneration step is operated.

[0002] In a dishwasher, a washing program is implemented that is comprised of various steps such as pre-washing, main washing and rinsing. In these machines, the washing and/or drying performance is inversely proportional to the hardness level of the water. As is known, the hardness of water results from the dissolved positive calcium or magnesium ions (Ca++ and Mg++) contained therein. In order to decrease the hardness of water, the water used in washing is first passed through an ion exchanger, for example a resin. The ion exchanger absorbs these ions from the water and gives off sodium ions (Na+) instead. Consequently, the hardness of water is reduced. However, in time, the ion exchanger cannot absorb the calcium and magnesium ions anymore. Therefore from time to time the ion exchanger is kept in a salt compound (for example NaCl) to extract the calcium and magnesium ions and to become enriched in sodium ions again. This process is called regeneration. Determining the frequency of the regeneration process is important for the performance of the dishwasher. If the regeneration process is performed more frequently than required, then salt consumption will increase unnecessarily. And when the regeneration process is delayed, then calcium deposits will be formed on the washed dishes.

[0003] Sensors are used in the technique for performing the regeneration process in the correct frequency. The frequency of the regeneration is adjusted according to data received from the said sensor.

[0004] In the state of the art German Patent Application No DE19841568 a dishwasher is explained that comprises an electrical conductivity sensor that measures the electrical conductivity of water both before and after water is passed through the ion exchanger. The decision for regeneration is given by registering and comparing the difference with previous values of conductivity from earlier treatment cycles detected by the two sensors. If the said difference is below a threshold value then it is understood that the ion exchanger is not functioning properly and regeneration is performed. In another implementation known in the technique, the state of the art European Patent Application No EP1252855, the explained dishwasher comprises a conductivity sensor that measures the conductivity of the ion exchanger. When to perform the regeneration process is determined according to the measured value.

[0005] A further prior art dishwasher is known from WO-A-01/30229.

[0006] However, in implementations known in the technique, in case data cannot be received from the sensor for determining when to perform regeneration for a reason such as malfunctioning of the said sensors or detachment of the electrical connections etc., the regeneration process cannot be performed at all and the washing performance of the machine is gradually reduced.

[0007] The aim of the present invention is the realization of a dishwasher wherein the regeneration process is performed at certain intervals even in the case that data cannot be received from the sensor that determines when to perform the regeneration process.

[0008] The dishwasher realized in order to attain the aim of the present invention is defined in the attached claims.

[0009] In the dishwasher of the present invention, a sensor is used that determines whether or not a regeneration process is required. In case data cannot be received from the sensor, the frequency in which the regeneration process will be performed is determined by the frequency value stored in the memory of the control unit.

[0010] In an embodiment of the present invention, the frequency in which the regeneration process will be performed is recorded in the control unit according to the data received while the sensor operates trouble free and when data cannot be received from the sensor, regeneration process is continued according to these values. The frequency in which the regeneration process will be performed can be determined by methods such as using the last one of the previous recorded values, average of the values or the moving average of the last 5 values.

[0011] In another embodiment of the present invention, water hardness level is measured and according to this value the frequency value is recorded in the memory of the control unit during the installation of the dishwasher by the user or the after sale service personnel and when data cannot be received from the sensor the regeneration process is performed according to the said value.

[0012] In another embodiment of the present invention, when data cannot be received from the sensor, washing process continues but a warning is delivered to the user for informing the malfunction of the sensor.

[0013] The dishwasher realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the schematic view of a dishwasher.

[0014] The elements illustrated in the figures are numbered as follows:

1. Dishwasher

2. Washing chamber

3. Ion exchanger

4. Salt chamber

5. Sensor

6. Control unit

[0015] The dishwasher (1) provides cleaning of the dishes in accordance with a washing program that includes at least some of the various steps like pre-washing, main washing, rinsing, drying, regeneration.

[0016] The dishwasher (1) comprises a washing chamber (2) wherein the dishes to be washed are emplaced, an ion exchanger (3) that reduces the hardness of the water to be delivered into the washing chamber (2) and a salt chamber (4) containing the salt required for the regeneration of the ion exchanger (3), being in communication with the ion exchanger (3) (Figure 1).

[0017] In the dishwasher (1), the ion exchanger (3) cannot absorb the calcium and magnesium ions of the water passing therethrough anymore with the lapse of time. Therefore, from time to time the ion exchanger (3) is kept in a salt-water solution delivered from the salt chamber (4) to extract the calcium and magnesium ions and to enrich with the sodium ions again. This process is called regeneration.

[0018] The dishwasher (1) comprises a sensor (5) that detects the ion exchanger (3) cannot absorb the calcium and magnesium ions of the water passing therethrough anymore and a control unit (6) that triggers the regeneration process in accordance with the data received from the sensor (5). The sensor (5), under normal work conditions, delivers data to the control unit (6) at the start of each washing process about whether or not the regeneration process will be performed.

[0019] The control unit (6) stores in the memory thereof a frequency of regeneration value (n) that is used to determine when the regeneration process will be performed in the case that data cannot be received from the sensor (5) due to a malfunction such as the electrical connection of the sensor (5) being detached or becoming inoperative. The control unit (6) performs the regeneration process periodically after a certain number (n) of washing programs in accordance with the recorded frequency of regeneration value (n) if data cannot be received from the sensor (5).

[0020] In an embodiment of the present invention, the frequency of regeneration value (n) is recorded in the memory of the control unit (6) during the installation of the dishwasher (1) by the user or the service personnel.

[0021] In another embodiment of the present invention, during the utilization of the dishwasher (1) the information relating to the performed frequency of the regeneration process in accordance with the data received from the sensor (5) is recorded in the control unit (6) as the frequency of regeneration value (n) and at each regeneration process this value is updated.

[0022] In another embodiment of the present invention, during the utilization of the dishwasher (1), the information relating to the performed frequency of regeneration process in accordance with the data received from the sensor (5) is recorded in the control unit (6) and the frequency of regeneration value (n) is determined by taking the average of the recorded data.

[0023] In yet another embodiment of the present invention, when regeneration process is performed according to the frequency of regeneration value (n) because data cannot be received from the sensor (5), the control unit (6) delivers a warning to the user for informing about the problem in the sensor (5).

[0024] By means of the present invention, a dishwasher (1) is designed that continues to operate by performing regeneration at a certain frequency (n) even in the case that data cannot be received from the sensor (5) that determines when to perform the regeneration process without the intervention of the user or the service personnel.

Claims

1. A dishwasher (1) that comprises a washing chamber (2) wherein the dishes to be washed are emplaced, an ion exchanger (3) that reduces the hardness of the water delivered into the washing chamber (2), a salt chamber (4) containing the salt required for the regeneration of the ion exchanger (3), being in communication with the ion exchanger (3), a sensor (5) that detects the ion exchanger (3) cannot absorb the calcium and magnesium ions of the water passing therethrough anymore and a control unit (6) that triggers the regeneration process in accordance with the data received from the sensor (5) and characterized by a control unit (6) that determines when to perform the regeneration process according to a frequency of regeneration value (n) stored in the memory thereof in the case that data cannot be received from the sensor (5).

2. A dishwasher (1) as in Claim 1, characterized in that the frequency of regeneration value (n) is stored in the control unit (6) by the user or the service personnel during installation.

3. A dishwasher (1) as in Claim 1, characterized in that the control unit (6) uses the information relating to the frequency of the regeneration processes performed in the previous usages according to the data received from the sensor (5), as the frequency of regeneration value (n).

4. A dishwasher (1) as in Claim 1, characterized in that the control unit (6) uses the average of the frequency values of the regeneration processes performed in the previous usages, according to the data received from the sensor (5), as the frequency of regeneration value (n).

5. A dishwasher (1) as in any one of the above claims, characterized in that the control unit (6) delivers a warning to the user for informing about the problem in the sensor (5) when data cannot be received from the sensor (5).

Ansprüche

1. Geschirrspülmaschine (1), umfassend eine Spülkammer (2), in die das zu spülende Geschirr gegeben wird, einen Ionentauscher (3), der die Härte des Wassers reduziert, das der Spülkammer (2) zugeführt wird, eine Salzkammer (4), die das Salz enthält, das zur Regeneration des Ionentauschers (3) erforderlich ist, und die mit dem Ionentauscher (3) in Verbindung steht, einen Sensor (5), der detektiert, dass der Ionentauscher (3) die Kalzium-und Magnesiumionen des Wassers, das durch ihn hindurchtritt, nicht mehr absorbieren kann, und eine Steuerungseinheit (6), die den Regenerationsvorgang entsprechend den Daten auslöst, die sie vom Sensor (5) empfängt, und gekennzeichnet durch eine Steuerungseinheit (6), die gemäß des Werts für die Regenerationshäufigkeit (n), der in ihrem Speicher gespeichert ist, bestimmt, wann der Regenerationsvorgang durchgeführt wird, falls die Daten nicht vom Sensor (5) empfangen werden können.

2. Geschirrspülmaschine (1) nach Anspruch 1, dadurch gekennzeichnet, dass der Wert der Regenerationshäufigkeit (n) vom Benutzer oder vom Wartungspersonal während der Installation in der Steuerungseinheit (6) gespeichert wird.

3. Geschirrspülmaschine (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Steuerungseinheit (6) entsprechend den vom Sensor (5) empfangenen Daten die Informationen zur Häufigkeit der bei früheren Benutzungen durchgeführten Regenerationsvorgänge als den Wert der Regenerationshäufigkeit (n) benutzt.

4. Geschirrspülmaschine (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Steuerungseinheit (6) entsprechend den vom Sensor (5) empfangenen Daten den Mittelwert der Häufigkeitswerte der bei früheren Benutzungen durchgeführten Regenerationsvorgänge als den Wert der Regenerationshäufigkeit (n) benutzt.

5. Geschirrspülmaschine (1) nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, dass die Steuerungseinheit (6) eine Warnung an den Benutzer bereitstellt und ihn über das Problem des Sensors (5) unterrichtet, wenn keine Daten vom Sensor (5) empfangen werden können.

Revendications

1. Un lave-vaisselle (1) comprenant une chambre de lavage (2) dans laquelle la vaisselle à laver est placé, un échangeur d'ions (3) qui réduit la dureté de l'eau distribuée dans la chambre de lavage (2), une chambre de sel (4) contenant le sel nécessaire à la régénération de l'échangeur d'ions (3), étant en communication avec l'échangeur d'ions (3), un capteur (5) qui détecte que l'échangeur d'ions (3) ne peut absorber plus les ions calcium et magnésium de l'eau qui passent à travers de celui-ci et une unité de contrôle (6) qui déclenchent le processus de régénération en conformité avec les données reçues du capteur (5) et caractérisé par une unité de contrôle (6) qui détermine le moment d'effectuer le processus de régénération selon une valeur de fréquence de régénération (n) stocké dans la mémoire de celle-ci dans le cas où aucun donnée peut être reçue du capteur (5).

2. Un lave-vaisselle (1) selon la Revendication 1, caractérisé en ce que la valeur de fréquence de régénération (n) est stockée dans l'unité de contrôle (6) par l'utilisateur ou le préposé à l'entretien lors de l'installation.

3. Un lave-vaisselle (1) selon la Revendication 1, caractérisé en ce que l'unité de contrôle (6) utilise les informations relatives à la fréquence des processus de régénération performés dans les usages antérieurs selon les données reçues du capteur (5), comme la valeur de fréquence de régénération (n).

4. Un lave-vaisselle (1) selon la Revendication 1, caractérisé en ce que l'unité de contrôle (6) utilise la moyenne des valeurs de fréquence des processus de régénération performés dans les usages antérieurs selon les données reçues du capteur (5), comme la valeur de fréquence de régénération (n).

5. Un lave-vaisselle (1) selon l'une quelconque des revendications précédentes, caractérisé en ce que l'unité de contrôle (6) avertit l'utilisateur afin d'informer sur le problème dans le capteur (5) lorsque aucun donnée peut être reçue du capteur (5).

Drawing