Patent Application
20050125911
The invention relates to a method for operating a water-containing appliance and a water-containing appliance for operating this method.
Water-containing appliances presently on the market, e.g. dishwashers, especially domestic dishwashers or washing machines, especially domestic washing machines, usually have a control device—a program controller—with which a cleaning program, which can be composed of partial program steps, is operated and on which a cleaning program selected by the user with pre-set and/or selectable parameters can be set.
In contrast however, a method for operating a dishwasher—a water-containing appliance—has become known from DE 1 96 51 344 A1 in which at the beginning of the program the dishwasher is merely set in operation and the parameters to be set for the continuation of the cleaning process are set depending on at least one detected parameter necessary for the continuation of the cleaning process and influenced by it, wherein at least one parameter is determined by means of a turbidity sensor from the turbidity of the cleaning liquid and whereby a completely automatically controlled method for operating a dishwasher—a water-containing appliance—is created in which incorrect operation by the user is completely eliminated and whereby the power and water consumption of the basically automatic dishwasher is restricted to the lowest possible level.
A disadvantage with using a turbidity sensor according to the method described previously however is that contaminants of the cleaning liquid which are completely dissolved in the cleaning liquid, and in this situation produce no turbidity of the cleaning liquid, naturally cannot be identified. In such a case, therefore, it is not possible to determine the cleaning state of the items to be cleaned using turbidity sensors.
In practice, it has been found that organic substances in particular have this property. Since the items to be cleaned in water-containing appliances, e.g. dishwashers or washing machines, are mainly contaminated with organic residue—food remains, sweat, skin particles etc, detection using a turbidity sensor is not suitable for determining the degree of cleaning of the items to be cleaned in relation to the cleaning from soluble organic contaminants.
It is thus the object of the invention to provide a method and a device for operating this method with which contaminants of the cleaning liquid which dissolve completely in the cleaning liquid and in this case produce no turbidity of the cleaning liquid, can be identified.
This object is solved by the method according to the invention with the features according to claim 1 and the water-containing appliance with the features according to the further independent claim. Advantageous further developments of the inventions are characterised in the dependent claims.
According to the method for operating a water-containing appliance according to the invention, in at least one partial program step the degree of contamination of the cleaning liquid is determined by means of a wet combustion and determining the combustion quantity.
In a so-called wet combustion organic components contained in liquids are oxidised (“burnt”). From the combustion quantity, for example, in the case of the cleaning liquid in a dishwasher or washing machine it is possible to determine how much invisible dissolved organic residue is contained in the liquid and thus to determine the degree of cleaning of the items to be cleaned. The invention has succeeded in providing a method with which contaminants of the cleaning liquid which dissolve completely in the cleaning liquid and in this case produce no turbidity of the cleaning liquid can be identified.
According to a preferred feature of the invention, a pre-determined quantity of ozone is passed into, passed through and passed out of a partial quantity of the cleaning liquid and the quantity of ozone which is passed out is measured by means of at least one arranged sensor and compared with the quantity of ozone which was passed in. It is known that ozone (O3) is completely constructed of oxygen atoms and is a high-energy form of oxygen and that ozone reacts rapidly especially with hydrocarbons, the hydrocarbons being converted into CO2 and eliminated. This explains the use of ozone in sterilising, disinfecting and cleaning agents (see, for example, EP 0 716 686 B1). Ozone is barely soluble in water which is why any falsification of the measurement result by dissolution of the ozone in the liquid to be measured is not to be expected.
The disinfection and deodorising of an interior of a microwave oven (DE-OS 39 04 418) and the deodorising of a dishwasher using ozone (see DE-OS 39 21 177) are also known. The treatment of supplied washing liquid by ozone for disinfection and deodorising (see DE-OS 35 40 335) is also known.
The method according to the invention is executed with said advantages using the water-containing appliance according to the invention.
The quantity of ozone which is passed out is preferably measured using at least one arranged sensor and compared in a control device with the quantity of ozone which is passed in.
In an especially advantageous fashion the program sequence of the water-containing appliance can be changed on the basis of the result of the comparison. Should it now be found that the quantities are approximately the same, the items to be cleaned are completely freed from organic substances and termination of the cleaning process can be initiated. However, should it be found that the quantities are different, the cleaning process is continued in any case.
Advantageously, on the basis of the result of the comparison, corresponding parameters of the program sequence of the water-containing appliance can be changed according to the difference determined between the quantities. Thus, according to the difference determined between the quantities, i.e., according to the degree of cleaning of the items to be cleaned which has already been achieved, measures can be introduced via the control device of the water-containing appliance, which for example bring about more intensive cleaning, i.e., higher temperature or longer running time etc.
In the water-containing appliance according to the invention it is furthermore advantageous that the residual quantity of ozone which is passed out again, acts directly on the items to be cleaned and there can assist the cleaning action of the cleaning agent used and/or contribute to the deodorising. The cleaning action of the cleaner is better activated by the action of the ozone whereby the use of tensides usually contained in such cleaning agents can be reduced. Ozone also has a bleaching effect especially on contaminants adhering to the items to be cleaned which can be utilised by acting on the items to be cleaned. The bleaching effect on the contaminants reduces the adhesion of the contaminants on the items to be cleaned and thus brings about faster and better cleaning. The ozone naturally also acts advantageously through the wet combustion in cleaning the remaining cleaning liquid.
According to an advantageous embodiment of the water-containing appliance according to the invention, after the end of the cleaning process ozone is fed into the interior of the appliance whereby a disinfection of the appliance interior and if desired and if these are still present, also of the items to be cleaned is achieved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10237854.1 | Aug 2002 | DE | national |
| PCT/EP03/08007 | Jul 2003 | WO | international |
