Dishwasher (10) for communities or for domestic use comprising a containing structure (12) inside which a washing chamber (16) is made in which the dishes (11) to be washed are arranged. The dishwasher (10) also comprises suitable holes (14) and nozzles (24) that selectively introduce steam into the washing chamber (16), so as to effect a heat-disinfection cycle of the dishes (11) using steam.
The present invention concerns a dishwasher for communities and for domestic use, for washing and the automatic heat-disinfection, using steam, of dishes, cutlery, pans or other kitchen utensils, hereafter collectively referred to simply as "dishes".
Dishwashers used in the field of communities or for domestic use normally perform a programmable washing cycle with hot water, followed by a rinsing cycle with hot water for a limited time.
Normal dishwashers available on the market do not provide any type of heat-disinfection of the dishes using steam, with the risk that bacteria or other microorganisms can remain thereon, with consequent possible health dangers for users, especially in the case of newborns or low immunity patients.
Washing and heat-disinfection apparatuses are also known, using water and/or steam, which are mainly used in the medical field, in hospitals and in research. The heat-disinfection cycle performed by such machines can be achieved by means of water taken to a temperature of 90/93°C, and guarantees a high level of disinfection from bacteria and viruses resistant to the washing cycle. The washing cycles are normally very long (more than 30 minutes) and are not acceptable for community uses.
Heat-disinfection apparatuses using water and/or steam are intended for totally different environments with respect to dishwashers for communities or for domestic use, and have different structures, materials, technologies and functions from the latter.
A dishwasher is also know which, at the end of the normal washing cycle, provides to deliver on the objects to be washed a jet of water at high temperature, as much as 85°C, in order to improve the effectiveness of the wash. However, even in this way, hot water at 85°C does not give any guarantee of heat-disinfection of the dishes to be washed since this temperature is guaranteed only for some seconds.
It is also known from US-A-2004/187898, a dishwasher which comprises a washing cabinet and a steam generator having water-feeding and steam-feeding holes provided at two ends thereof. Water fed into the steam generator through the water-feeding hole is quickly heated to produce high-temperature steam, which is sent through the steam-feeding hole into a steam pipeline distributed over the inner surfaces of the washing cabinet. The steam is sprayed into the washing cabinet through spray holes made on the steam-feeding pipeline, to sterilize and soften hardened food residues on the dishware positioned in the washing cabinet for washing, making the dishware effectively cleaned and sterilized. This known dishwasher has the disadvantage that the steam-feeding holes separated from the water-feeding holes, and fixedly disposed on the inner surfaces of the washing cabinet. Therefore, in this known solution, the steam is sprayed only in a univocal and fixed direction in respect to the dishes, so that it interests only a restricted area of the dishes positioned in front of the steam-feeding holes. This limit does not allow either a uniform heat-disinfection of the whole surface of the dishware positioned in front of the steam-feeding holes, or a heat-disinfection of all the dishware positioned in the washing cabinet.
US-A-3,717,159 discloses a pot and pan washer and sterilizer apparatus comprising a soaking station, a scraping station, a washing station, and a sterilizing station, arranged aligned one with respect to the other. Each station comprises a detachable independent assembly, which may be selectively chosen in accordance with the predetermined functions to be performed. The basic assembly is a soaking station which includes a sink for soaking pots and pans containing adhering refuse. The addition of a scraping station provides a convenient area for storing and scraping cooking utensils containing adherent refuse. A washing station includes a second sink and provides an agitation and washing structure for removing any remaining refuse from the utensils. However, this known solution has the disadvantage to provide a lot of stations for washing and sterilizing pots, pans and other dishes, which causes an increase in costs and installation dimensions.
One purpose of the present invention is to achieve a dishwasher for communities or for domestic use, of a traditional type in itself, wherein an auxiliary function is added for the heat-disinfection using steam of the dishes to be washed, without increasing the overall dimensions of the dishwasher.
The Applicant has devised, tested and embodied this invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
The present invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with this purpose, a dishwasher according to the present invention comprises a containing structure, which can be of standard size, inside which one or more washing chambers are provided in which the dishes to be washed are arranged.
The dishwasher also comprises steam generation means for generating steam, and introduction means for the selective introduction of the steam inside said one or more washing chambers, so as to effect a cycle of heat-disinfection of the dishes, after they have been washed, keeping a constant temperature in the washing chamber for a pre-established time.
Inside the washing chamber, at least a washing member is provided to deliver desired jets of water through a plurality of holes, in order to wash the dishes.
According to a feature of the present invention, the steam is introduced into said washing chamber through the holes of said washing member, and the washing member comprises at least a rotating element able to be selectively made to rotate by means of a centrifugal thrust exerted either by water, or by steam, delivered by said holes.
Therefore, with the solution of the present invention the steam enters inside the washing chamber through the same holes that are normally provided on usual rotary washing members present in any dishwasher available on the market, so that the overall dimensions of the dishwasher are not increased due to the installation of the steam generation means.
Another advantage of the present invention is that the rotation of the washing members during the delivery of steam determines a uniform distribution of the steam inside the washing chamber and a consequential uniform heat-disinfection of all the dishware positioned inside it.
The steam generating means can be arranged either inside the containing structure, or outside the latter. For example the steam can come from an external source, and introduced inside the containing structure in order to achieve said heat-disinfection cycle.
In this way, a dishwasher of a substantially known type, either for communities or for domestic use, also performs the functions of heat-disinfection with consequent advantages in terms of reducing the health risk.
In a preferential embodiment, the washing chamber is water-tight, and the steam generation means are conformed so as to take the steam to a temperature such that, when introduced into the washing chamber, it has a temperature of about 100°C and that it saturates the washing chamber.
In another form of preferential embodiment, the steam generation means comprise a boiler, positioned below the washing chamber, in the same technical compartment where a pump is normally positioned to recircle the water used, or in another, adjacent compartment. It is also possible to use, where present, steam produced other than by the boiler.
Another advantage of the present invention is that a single pump can be used and a single line to feed the water, both for washing and also for the heat-disinfection.
Moreover, the simplicity of construction of the present invention does not preclude the possibility of equipping the apparatus thus made with any of the operating functions normally present in known dishwashers.
These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawing wherein:
With reference to fig. 1, a dishwasher 10 for communities or for domestic use according to the present invention is suitable for washing and heat-disinfecting with steam a plurality of dishes 11, such as for example plates, forks, glasses, pans or other commonly used domestic objects.
The dishwasher 10 comprises a containing structure 12 of parallelepiped shape, and can be of substantially standardized size, for example for built-in use.
The containing structure 12 comprises inside a frame 13 that defines a technical compartment 15, below, and a washing chamber 16, above. To be more exact, the dishes 11 are arranged in order on one or more loading trays 19, selectively removable from the washing chamber 16, for example by means of sliding guides 18, in a substantially known manner.
Moreover, a door 17 is hinged on the frame 13 and is able to allow, in a closed position, the water-tight closure of the washing chamber 16 and, in the open position, selective access to the washing chamber 16.
Inside the washing chamber 16 in this case two rotors 20 and 21 are provided, respectively lower and upper, able to deliver through holes 14 desired jets of water towards the top and towards the bottom in order to wash the dishes 11. The jets of water have a pressure determined by a hydraulic pump 23 which takes a determinate quantity of water from the washing chamber 16 and pumps it to the two rotors 20 and 21. In this way, the water emerging from the holes 14 generates a centrifugal thrust that makes the rotors 20 and 21 rotate.
The hydraulic pump 23 is arranged inside the technical compartment 15.
According to a characteristic feature of the present invention, a boiler 25 is also arranged in the technical compartment 15, and is connected both to the water supply and also to the washing chamber 16. It is able to transform a desired quantity of water into a mass of steam at high temperature, for example about 100°C. The steam generated is introduced, through the holes 14, into the washing chamber 16 at a temperature of at least 100°C.
The dishwasher 10 as described heretofore functions as follows.
Once the normal washing cycle of the dishes 11 has been started, for example by means of a command and control unit of a known type not shown here, the hydraulic pump 23 introduces the pressurized water into the two rotors 20 and 21, through the holes 14 of which the water emerges in jets.
Once the washing cycle is finished, a cycle of heat-disinfecting of the dishes 11 is started using steam, wherein the boiler 25 generates a mass of steam which is introduced inside the washing chamber 16. As said, the steam introduced into the washing chamber 16 has a temperature of at least 100°C, thus effecting a heat-disinfection of the dishes 11 arranged in the loading tray 19.
It is clear, however, that modifications and/or additions of parts may be made to the dishwasher 10 as described heretofore, without departing from the field and scope of the present invention.
For example, it comes within the field of the present invention to provide that the steam can be introduced inside the washing chamber 16 also through a plurality of auxiliary dedicated nozzles 24 (shown by a line of dashes) for the introduction of steam, distinct from the holes 14 of the two rotors 20 and 21, so that the washing cycle and the heat-disinfection cycle can also be at least partly superimposed in a common step, in order to be able to wash and heat-disinfect the dishes 11 simultaneously.
It also comes within the field of the invention to provide that the dishwasher 10 can include means to dry the dishes, or other.
It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of dishwasher for communities or for domestic use, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.