Dishwasher with treatment-fluid generator, and method of operating such a dishwasher

Abstract

A dishwasher for crockery or utensils, which is designed as a box-type dishwasher or as a conveyor dishwasher, wherein the dishwasher ( 1 ) has at least one wash tank ( 12 ), for accommodating a treatment fluid ( 20 ), and at least one final-rinse system, for supplying a final-rinse fluid ( 42 ). In order for it to be possible for expensive wash chemicals to be dispensed with for the most part, the dishwasher ( 1 ) also has a treatment-fluid generator ( 100 ) with at least one electrolysis device ( 109 ), wherein the treatment-fluid generator ( 100 ) is, or can be, connected to the wash tank ( 12 ) and is designed to supply an alkaline solution in the wash tank ( 12 ) of the dishwasher ( 1 ) by electrolysis.

1 . A dishwasher ( 1 ), which is designed as a box-type dishwasher or as a conveyor dishwasher, wherein the dishwasher ( 1 ) has at least one wash tank ( 12 ), for accommodating a treatment fluid ( 20 ), and at least one final-rinse system, for supplying a final-rinse fluid ( 42 ),
 characterized in that   the dishwasher ( 1 ) also has a treatment-fluid generator ( 100 ) with at least one electrolysis device ( 109 ), wherein the treatment-fluid generator ( 100 ) is, or can be, connected to the wash tank ( 12 ) and is designed to supply an alkaline solution in the wash tank ( 12 ) of the dishwasher ( 1 ) by electrolysis.   
     
     
         2 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the final-rinse system has a storage container ( 30 ), for accommodating a final-rinse concentrate, and a multiplicity of final-rinse nozzles ( 18 ), for spraying washware with a final-rinse fluid ( 42 ), wherein the storage container ( 30 ) is, or can be, connected to the wash tank ( 12 ) such that optionally the final-rinse concentrate and/or the final-rinse fluid ( 42 ) can be metered out of the final-rinse system into the wash tank ( 12 ).   
     
     
         3 . The dishwasher ( 1 ) as claimed in  claim 2 ,
 wherein the storage container ( 30 ) is, or can be, connected directly to the wash tank ( 12 ), and therefore it is an option for the final-rinse concentrate to be metered directly into the wash tank ( 12 ).   
     
     
         4 . The dishwasher ( 1 ) as claimed in  claim 2 ,
 wherein the final-rinse system has at least one boiler ( 40 ), which has a fresh-water connection ( 50 ) and is, or can be, connected to the final-rinse tank ( 30 ) for the supply of a final-rinse fluid ( 42 ), and wherein, in addition, the boiler ( 40 ) is, or can be, connected to the wash tank ( 12 ) such that it is an option for the final-rinse fluid ( 42 ) to be metered out of the boiler ( 40 ) into the wash tank ( 12 ).   
     
     
         5 . The dishwasher ( 1 ) as claimed in  claim 2 ,
 wherein the treatment-fluid generator ( 100 ) has a first metering pump ( 110 ), for controlled metering of the alkaline solution into the wash tank ( 12 ), and wherein the final-rinse system has a second metering pump ( 38 ,  48 ), for controlled metering of the final-rinse concentrate and/or of the final-rinse fluid into the wash tank ( 12 ).   
     
     
         6 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the dishwasher ( 1 ) has a control device which is, or can be, connected to the first and second metering pumps ( 38 ,  48 ,  110 ) and is designed to activate the first and second metering pumps ( 38 ,  48 ,  110 ) so as to achieve a treatment fluid ( 20 ) with a pH value of at least  9 , in the wash tank ( 12 ).   
     
     
         7 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the wash tank ( 12 ) has at least one sensor means for measuring the pH value of the treatment fluid ( 20 ) located in the wash tank ( 12 ).   
     
     
         8 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the treatment-fluid generator ( 100 ) is designed to supply an alkaline solution with a pH value of 10 to 14, in particular of 11.5 to 13.   
     
     
         9 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the treatment-fluid generator ( 100 ) is also designed to generate an acid solution which has a pH value of 1 to 7, in particular 2.5 to 6, and is suitable for disinfecting components of the dishwasher ( 1 ) and/or for disinfecting washware.   
     
     
         10 . The dishwasher ( 1 ) as claimed in  claim 9 ,
 wherein the dishwasher ( 1 ) has a control device which is designed to make a selection between a first operating mode, for washing the washware with treatment fluid ( 20 ) at a first temperature, and a second operating mode, for washing the washware with treatment fluid ( 20 ) at a second temperature, which is lower than the first temperature, and wherein the control device is also designed to initiate an operation for spraying the washware with the acid solution in the second operating mode.   
     
     
         11 . The dishwasher ( 1 ) as claimed in  claim 1 ,
 wherein the electrolysis device ( 109 ) of the treatment-fluid generator ( 100 ) is, or can be, connected to a fresh-water connection ( 101 ), and to an additive container ( 107 ), so that a starting solution can be supplied for the electrolysis device ( 109 ).   
     
     
         12 . The dishwasher ( 1 ) as claimed in  claim 11 ,
 wherein the dishwasher ( 1 ) has a water-treatment device with a salt container for accommodating sodium chloride, and wherein the additive container ( 107 ) is, or can be, connected to the salt container such that sodium chloride from the salt container can be fed to the additive container ( 107 ).   
     
     
         13 . The dishwasher ( 1 ) as claimed in  claim 12 ,
 wherein the additive container ( 107 ) is designed as a salt container for accommodating sodium chloride, wherein feeding fresh water into the additive container ( 107 ) makes it possible to supply a salt solution, in particular a saturated salt solution, which serves as a starting solution for the electrolysis unit ( 109 ) or for supplying the starting solution for the electrolysis device ( 109 ).   
     
     
         14 . A method of operating a dishwasher ( 1 ) as claimed in  claim 1 , wherein the method has the following steps:
 feeding fresh water into a tank of the electrolysis unit and/or into a salt container of the dishwasher ( 1 );   operating the electrolysis unit in order to generate an alkaline solution from the fresh water fed to the tank and/or salt container;   feeding the alkaline solution into a wash tank ( 12 ) of the dishwasher ( 1 ); and   spraying washware with the alkaline solution located in the wash tank ( 12 ).   
     
     
         15 . The method as claimed in  claim 14 , 
       wherein the method, prior to the operation of spraying the washware, has the following steps:
 supplying a final-rinse concentrate in a storage container ( 30 ) of the dishwasher ( 1 ); and 
 metering the final-rinse concentrate into the alkaline solution located in the wash tank ( 12 ). 
 
     
     
         16 . The method as claimed in  claim 15 , 
       wherein the final-rinse concentrate has at least one wash additive comprising complex formers and/or surface-active substances and/or anti-foaming agents and/or corrosion inhibitors. 
     
     
         17 . The method as claimed in  claim 14 , wherein the electrolysis unit is operated such that the alkaline solution has a pH value of 10 to 14, in particular of 11.5 to 13. 
     
     
         18 . The method as claimed in  claim 14 , 
       wherein sodium chloride is metered into the fresh water, prior to the alkaline solution being generated by the electrolysis unit, so as to achieve a common-salt solution with a concentration of preferably 1 to 20 g/l, which serves as a starting solution for the electrolysis unit, or to achieve a saturated common-salt solution which provides a starting solution for the electrolysis unit with a concentration of 1 to 20 g/l. 
     
     
         19 . The method as claimed in  claim 18 , 
       wherein the sodium chloride can be removed from a water-treatment device of the dishwasher and is metered into the fresh water. 
     
     
         20 . The method as claimed in  claim 14 , 
       wherein an acid solution, in particular hypochlorous acid, is generated at the same time as an alkaline solution is generated, wherein at least some of the acid solution is directed, for disinfecting purposes, into the treatment chamber ( 10 ) of the dishwasher ( 1 ). 
     
     
         21 . The method as claimed in  claim 20 , 
       wherein the method, following the step of spraying the washware with the alkaline solution, also has a step for spraying the washware with the acid solution.