The invention relates to a method for cleaning, sterilising and disinfecting dishes and other kitchen utensils according to the generic definition of Claim 1 and a device for implementing the method.
Diverse forms of methods and devices for cleaning household objects, dishes or other kitchen appliances are already known. To attain a good degree of washing and cleanliness of items cleaned, their surfaces must be freed from soiling, bacteria or germs. This can be done in a relatively simple way, for example by washing with a household appliance or an electrically operated dishwasher. To this end, soiled dishes are placed in contact with a wash liquid in the dishwasher.
The soiled items or dishes are first placed in the dishwasher. Then, in particular tap water or household water and a detergent, in the form of a powder or a liquid, for example, are added. By means of a heating element, for example, the water or the wash liquid is brought to a required temperature, depending on the previously selected program, or the wash liquid or the water is mixed with the detergent. A chemical or physical dissolution process can then taken place in which, for example, the surface of the dishes cleaned is freed from soiling, bacteria and germs or these are transferred to the wash solution. After the actual wash operation, the surface of the dishes or kitchen appliances can be rinsed, for example with pure water. The wash or drying operation has ended after drying of the dishes or kitchen appliances thus treated or cleaned.
The task of the invention is to provide a method or a device to make it possible to further improve cleaning of domestic items, dishes, etc. or other kitchen appliances or to advantageously enable them in relation to economic and technical aspects.
This task is resolved by Claims 1 and 11.
Expedient variants of the invention are pointed out in the dependent claims.
On the one hand, the invention is based on a method for cleaning, sterilising and disinfecting dishes and kitchen utensils by means of a wash liquid. One essential aspect of the invention lies in the fact that, by direct application of electrical current to an electrode arranged in the wash liquid that is embodied as a diamond and/or lead-tin electrode, OH radicals are generated in the wash liquid that enable cleaning, sterilisation and disinfection of the dishes and other kitchen utensils. This ensures effective and reliable cleaning or sterilisation and disinfection of dishes and kitchen utensils. In particular, high volumes of OH radicals can be generated with the method conforming to the invention or with the aid of the proposed electrodes. In particular, the OH radicals generated can make it possible to realise the cleaning method without detergents or without cleaning additives that were previously additionally required. It is especially advantageous that water or drinking water suffices as the wash liquid, out which OH radicals are generated with the proposed electrodes. OH radicals are distinguished, among other things, by their high activities and their ability to react or to oxidise in comparison with oxidising substances. Moreover, a cell-killing effect can be achieved with the OH radicals in relation to microorganisms, germs and bacteria.
It is also advantageous that electrical current, which is generally available anyway, is used for the method conforming to the invention. For the method, the electrical current is impressed directly on the electrodes within the dishwasher. The electrodes are preferably located in the circulating water and are in particular connected to a variable power supply unit. Thus, the electrodes can be placed in a comparably intensive contact with the wash liquid or the water pr water or, if applicable, further substances contained therein can wash around them. Any occurring hydrogen formation and the related ability to react with oxygen can be easily taken into consideration with known arrangements, e.g. by using semi-permeable diaphragms or a possible hazard potential can be reliably eliminated.
A further essential advantage of using diamond or lead-tin electrodes is that they do not entail any detrimental effect as can arise when using other electrode materials in aqueous systems. In the case of known electrodes, in particular those containing metal, for example consisting of platinum, portions or slight traces of these metals, for example atomic platinum or substances containing platinum can dissolve in the wash liquid or the surrounding water and can settle on the surface of the dishes and kitchen utensils. From there, platinum can be picked up by a person using the dishes through his or her food, thus reaching into the person's body. Platinum, however, in particular in comparatively low doses, is a substance that is hazardous to health or, in particular, a substance that poisons the cells. According to the invention, the detrimental use of platinum electrodes can be avoided.
It is also proposed to use a diamond and/or lead-tin anode. By the use of synthetically manufacturer diamond electrodes and/or lead-tin electrodes, for example, the extremely effective OH radicals can be generated during electrolysis, which particularly takes place on the anode. In principle, one or even several anode(s) made of the proposed substances can be provided for in the wash liquid.
The wash liquid is preferably mixed with agents for increasing electrical conductivity, in particular dishwashing detergent. To increase the electrical conductivity of the wash liquid or of the water washing around the electrodes, corresponding substances can be placed or dissolved in it. For example, a commercially available dishwashing detergent and/or an inorganic salt solution that is not decomposable can be used to increase electrical conductivity or as an electrolyte liquid. For example, Na2SO4r Na3PO4, NaCl, H3B03 or a mixture of these salts can be used here. These substances or detergents are placed in dishwashers in particular via devices that ought to be well-known in themselves. Thus, for example, cleaning, sterilisation or disinfection of surfaces of the items to be cleaned can be enabled with commercially available wash solutions. On the one hand, the wash liquid or the wash solution serves as an electrolyte for applying electrical current to the solution and, on the other hand, it simultaneously serves as a wash solution for chemical dissolution of soiling or for electrochemical sterilisation, cleaning and disinfection of the surfaces of dishes. The generation of OH radicals on the anode or the possible simultaneous generation of the strong oxidation agents oxygen and/or ozone thus largely takes the place of possible additives for in particular chemical dissolution or removal of soiling by the wash solution.
It is particularly advantageous that a pulsating or continuous current is applied directly to the electrode arranged in the wash liquid. Thus, the necessary concentrations or volumes of OH radicals in the wash liquid can be reliably generated. In particular, pulsating application of current enables appreciably greater generation of OH radicals than when the current applied is not pulsating. Therefore, one quite essential point of the invention is to be seen in the fact that direct current is applied to the electrodes which is preferably impressed on the electrodes directly or in a pulsating fashion. As a result of the thus possible comparatively high OH radical generation rates or the thus achieved comparatively high OH radical concentrations in the wash liquid, wash times or times for a wash cycle can be shortened clearly in comparison with known processes or devices previously used. This is particularly attributable to the generation of highly efficient OH radicals on the anode or the simultaneous chemical and/or physical washing and sterilisation during the cleaning process. Pulsating current application can basically take place in accordance with one of different profiles that can be stipulated, for example in accordance with a wavy or sinusoidal, ramp-like or spiked profile as a function of time. An alternating current is preferably applied directly to the electrode arranged in the wash liquid. By means of an alternating application of current to the electrode, in which in particular the polarity alternates from plus to minus or the electrical polarity is reversed, particularly effective generation of OH radicals can be achieved.
It is also proposed to use a mixture of organic and/or inorganic wash solutions, such as commercially available detergents for cleaning, sterilisation and disinfection of dishes and other kitchen utensils. Additional positive effects during the cleaning process can be realised in this way. For example, surface-active or enzymatically active substances can clearly improve the cleaning effect. The process according to the invention is preferably to be used in combination with or with the use of commercially available detergents.
In a further preferred embodiment of the invention, dishes are cleaned by OH radicals and simultaneous chemical and physical removal of soiling.
In yet another preferred embodiment of the invention the wash liquid for cleaning, sterilising and disinfecting dishes and other kitchen utensils consists of a mixture of water and an inorganic salt such as Na2SO4 or sodium sulphate, Na3PO4 or sodium phosphate, NaCl or sodium chloride and/or H3B03 or boric acid and/or a mixture of individual components. With these substances or, if applicable, a mixture of the individual components, particularly high cleaning performance can be achieved with the process conforming to the invention. Thus, the electrolyte solution can be provided as an alkaline aqueous wash solution or with conventional detergents or mixtures of the aforementioned salts.
It is particularly advantageous that the wash liquid for cleaning, sterilising and disinfecting dishes and other kitchen utensils is created out of a mixture of water and a commercially available detergent and/or one of the inorganic salts Na2SO4 or sodium sulphate, Na3PO4, or sodium phosphate, NaCl or sodium chloride and/or H3B03 or boric acid, and/or a mixture of the individual components and/or a mixture of organic/inorganic aqueous solutions that is used as the electrolyte. The process according to the invention can be realised effectively and reliably with such an electrolyte.
It has proven particularly advantageous for the current density on the electrode to be set in amperes per unit of area specifically to the material to be cleaned, and for the current density to amount to between approx. 5 amperes per square decimetre (A/dm2) and approx. 300 amperes per square decimetre (A/dm2). A comparably high efficiency of the process according to the invention can be ascertained in the aforementioned current density range.
The invention is also based on a device to be able to implement the aforementioned process. One essential aspect lies in the fact that an electrolysis cell with an electrode pair encompassing a diamond electrode for generation of OH radicals is integrated directly in a wash water circuit of a dishwasher. In the thus formed device, the advantages already discussed above can be realised in a cleaning device or a dishwasher.
In a preferred embodiment of the device according to the invention, there is an electrically insulated spacer that prevents an electrical short-circuit between the anode and the cathode. Thus, the device according to the invention is able to meet the required safety standards when using electrical current in electrolysis cells. With an electrically insulated or insulating spacer on the corresponding zones of the electrolysis cell, negative influences due to an electric short-circuit in the energised state, in particular of the electrode pair, can be ruled out.
In the case of a further advantageous embodiment of the device according to the invention it is proposed for the electrolysis cell to be fed by the wash water sump by means of a circulation pump and for the dishes to be contacted via a spray arm. In this way, electrolyte or wash liquid collecting in the wash water sump can be compactly and reliably fed to the electrolysis cell with a comparatively robust circulation pump. Via the energised electrodes or the electrolysis cell, OH radical enrichment will then take place as described and then the wash liquid is brought into contact with the objects or dishes to be cleaned by means of the circulation pump via the spray arm or a correspondingly shaped brew device.
It is also proposed for an anode to arise out of a material that permits an overvoltage of the anode and thus OH radical generation. By means of a correspondingly designed anode or a corresponding anode material, in relation to an applied voltage on the anode a voltage can be achieved in such a way that OH radical generation is possible or a comparatively high rate of OH radical generation can be realised.
It is also proposed for the anode encompasses a synthetically manufactured diamond. All dimensions, shapes or compositions of the diamond electrode can be reproducibly manufactured with a synthetically manufactured diamond. For example, a synthetically manufactured diamond can be applied to titanium sheet or another suitable substrate material such as plastic.
Preferably, a diamond material, in particular a synthetic diamond material, can be doped with specific substances or compounds. For example, different metals can be incorporated in the synthetic diamond. In particular, a synthetic diamond doped with boron exhibits particularly advantageous properties in relation to an overvoltage of the anode thus formed. As a result of doping of the synthetic diamond, the diamond is made conductive or electrically conducting.
The special characteristic of the diamond electrode is also the form of water decomposition. While water is usually split during electrolysis into hydrogen (H2) and oxygen (02), the diamond electrode supplies a certain operating range instead of oxygen the highly reactive or oxidative hydroxyl radical or OH radical and/or the intermediate or decomposition product ozone or 03.
Thus, for example, sterilisation of drinking water, for example, can be achieved. In particular, the chemical oxygen requirement value or the CSB value in sewage systems can be reduced. In these application areas, publications by the firms Waco, Condias and Gerus have been published in Germany. In them, the use of diamond electrodes is discussed exclusively for the sewage or drinking water industry.
It is also proposed for the anode consists of a platinum-coated electrode. A robust or electrochemically particularly resilient electrode can be provided in the form of a platinum-coated metal electrode. Besides the diamond electrode, which exhibits considerable stability in relation to aggressive and in particular alkaline, wash solutions, a platinum-coated metal electrode can in particular be used advantageously as the anode.
With reference to the figures, further characteristics and advantages of the invention are pointed out in the drawing.
In detail, the figures show:
The arrangement shown in
The electrolysis device from
With the proposed device or the process conforming to the invention it is in particular possible to save on commercially available detergents comprising tensides, phosphates or other additives, thus not only achieving saving effects, but also protecting resources or relieving the burden on the environment by reducing pollution of waste water from the cleaning device, or to realise a general energy saving thanks to shortened cleaning times.
Number | Date | Country | Kind |
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A 757/2005 | May 2005 | AT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2006/004125 | 5/3/2006 | WO | 00 | 2/12/2008 |