ITPN20120063A1 - DISHWASHER WITH RECYCLING WASHING LIQUID FOR NEXT WASHING CYCLES - Google Patents

Description

DISHWASHER WITH RECYCLING THE WASHING LIQUID FOR

SUBSEQUENT WASHINGâ €

DESCRIPTION

TECHNICAL FIELD OF INVENTION

[0001]. The present invention relates to a washing machine in particular for dishes, in which it is possible to use the same washing liquid for several successive washing cycles, without requiring further supplies of water from the water mains. STATE OF THE TECHNIQUE

[0002]. In the perspective of sustainable development, the reduction of waste, and therefore of the consumption of electricity and water, plays a role of fundamental importance.

[0003]. Therefore, in recent years the orientation of manufacturers of household appliances, in particular dishwashers and washing machines, has been to design new machines capable of operating with the least amount of water possible, while ensuring adequate hygiene standards.

[0004]. Dishwashing machines are known in which the water loaded for a washing phase can be reused to operate a subsequent washing phase, belonging to the same washing cycle or belonging to a subsequent washing cycle. In particular, thanks to an internal storage tank, the water used for the last rinsing phase of a cycle is reused, possibly added to detergent, to operate the first washing phase of the next cycle; after which the washing liquid must be drained.

[0005]. The term â € œwashing cycleâ € means a complete cycle for washing dishes, comprising a plurality of washing phases in succession, such as, for example, actual washing phases, rinsing phases and drying phases, at the end of which the dishes are clean and can be removed by the user.

[0006]. Document WO2012 / 084492, on the other hand, shows a dishwashing machine in which it is possible to reuse the liquid used in a washing cycle for one or more subsequent washing cycles.

[0007]. This dishwashing machine comprises a washing chamber in which the objects / dishes to be washed are positioned, a well arranged below said washing chamber, inside which the washing liquid is collected during the washing cycle, after passage through a first microfilter, and first pumping means, which return the washing liquid from the collection well to the washing chamber.

[0008]. Furthermore, there is a storage tank in which the liquid used in a washing phase of the washing cycle is stored to be reused in a subsequent washing phase or in a subsequent washing cycle; to do this, second pumping means take the liquid collected inside the collection well and send it, after passing through a second filter, to the storage tank.

[0009]. The operation of the dishwashing machine is as follows: during the washing cycle, the washing liquid used passes into the collection well after passing through said first microfilter and is reintroduced into the washing chamber by means of said first pumping means. At the end of each washing phase, the liquid collected in the collection well is sent, through said second pumping means, to the storage tank, then passing through said second filter, to then be reused in the subsequent washing phases, or cycles of subsequent washing, without requiring the addition of further water from the water mains.

[0010]. Additional for disinfection and purification of the washing liquid can be provided in the ducts leading to the storage tank or inside the tank itself.

[0011]. A drawback that is encountered in the dishwashing machine described above consists in an inadequate level of hygiene of the washing liquid: in fact, the liquid stored in the tank, previously filtered and possibly treated with UV rays or ozone, is introduced back into the well before being sent again in the washing chamber by means of said first pumping means. However, generally, the collection sump is by its nature a receptacle for dirt and germs, being arranged below the washing chamber; furthermore, inside it may be present some washing liquid not yet treated or particles of impurities adhering to the surface of the filter or to its walls, with which the treated / purified liquid mixes before being sent to the dishes.

[0012]. In this way, not only the degree of hygiene is considerably lowered but, absurdly, a waste of resources is obtained as, after having purified a portion of liquid, it is mixed again with the impurities, thus going to nullify the work done. .

[0013]. Furthermore, for the same reason, the washing liquid can only be reused for a limited number of cycles, generally a maximum of three, after which it would be too contaminated by the impurities of the previous washes to be further recycled.

SUMMARY OF THE INVENTION

[0014]. The main task of what forms the subject of the present invention is to provide a dishwashing machine that is capable of minimizing the consumption of water and electricity during its use.

[0015]. Within the scope of the aforementioned task, an object of the present invention is to provide a dishwashing machine capable of operating countless consecutive washing cycles without drawing from the water from the mains water supply and without discharging into the sewer, creating a real circuit closed, substantially sealed.

[0016]. This aim must be achieved while ensuring an adequate degree of sanitation of the dishes.

[001] Not least object is that of devising a dishwashing machine which achieves the above mentioned aim and objects by exploiting the usual and known plants, machinery and equipment.

[0017]. The aim and objects indicated above, and others which will appear better below, are achieved by implementing a process as defined in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]. Further characteristics and advantages obtainable by means of a dishwashing machine according to the present invention will become more evident from the following description of a particular, but not exclusive, embodiment, illustrated purely by way of non-limiting example with reference to the attached figure 1, in which à A dishwashing machine according to the present invention is schematically shown.

DETAILED DESCRIPTION OF THE INVENTION

[0001]. With reference to Figure 1, a washing machine 10 according to the present invention, in particular a dishwasher, comprises an external cabinet (not shown) which encloses a washing chamber L equipped with sprinkler means 11 formed for example by suitable rotating spray arms or the like. suitable for spraying a washing liquid, substantially formed by water added with a washing agent, on the dishes housed therein, generally arranged on a removable trolley, exerting a mechanical action to remove the dirt.

[0019]. The dishes are washed by means of a washing cycle, which includes a succession of washing phases organized on the basis of a specific washing program, which varies according to the load, the type of dishes to be washed and the degree of dirt of the same. A washing cycle begins with the insertion of dirty dishes into the dishwasher 10 and ends with the user extracting the clean dishes.

[0020]. Said washing chamber L communicates at the bottom with a collection tank A in which, at the end of each washing phase and each washing cycle, the washing liquid is collected by gravity, which is then stored in it until the moment of a subsequent use, ie at the start of a new phase or a new washing cycle. In particular, said collecting tank A preferably has such dimensions as to substantially contain all the washing liquid used in the dishwashing machine 10 to carry out the washing of the dishes.

[0021]. In an initial phase of the operation of the dishwashing machine 1, said tank A is fed with water up to a desired level, for example through a hydraulic circuit known per se and not shown, which draws from the municipal water network; in the absence of connection to the water mains, said tank A can be filled manually by means of a top-up tank.

[0022]. Said dishwashing machine 10 also comprises a recirculation circuit 100 for the washing liquid: said circuit 100 comprises one or more treatment stations arranged in succession, each of which is provided with means for the chemical and / or physical and / or bacteriological of the washing liquid, such as filter media and disinfection media.

[0023]. Said treatment stations are arranged and configured in such a way as to purify the washing liquid to make it reusable in the next washing cycle; suitable pumping means are provided to impart the pressure necessary to the washing liquid to pass through the treatment stations of said recirculation circuit 100.

[0024]. According to a particularly advantageous feature of the invention, said recirculation circuit 100 is connected on one side to said collection tank A and on the other it is directly connected to said sprinkler means 11 to introduce the liquid into the washing chamber L treated and purified by said one or more treatment stations.

[0025]. A possible particularly advantageous embodiment of the invention is described below, assuming that treatment stations in different numbers and of different types than those indicated can also be used as long as they are suitable for the purpose indicated above, as easily understood by a industry expert.

[0026]. First pumping means B, such as for example a pump, are connected by means of a suction duct 12 to the bottom of the collection tank A, and are adapted to withdraw the washing liquid contained therein and send it, through a delivery duct 13, to a first treatment station D comprising first filtering means, such as for example a fine mesh filter or micro-filter, capable of removing impurities in the form of solid particles in suspension from the washing liquid, retaining them on its surface.

[0027]. Advantageously, in order to ensure optimal operation of the filtering and / or disinfection means placed downstream, the filter used in said first treatment station D is configured in such a way as to remove solid particles having dimensions up to 2µm from the washing liquid. Furthermore, advantageously, said filter is arranged in such a way that it can be removed by the user to replace or clean it when it has reached saturation.

[0028]. Preferably, selective diversion means C for the washing liquid, such as a three-way valve, are associated with said delivery duct 13 upstream of said first treatment station D: said valve C can assume a first operating position, in which it allows the passage of the washing liquid towards said first treatment station, and a second operative position which diverts it towards the drain M in the sewer.

[0029]. Second pumping means E are preferably provided to withdraw the liquid leaving said first treatment station D and send it to a second treatment station F comprising second filtering means, preferably one or more semipermeable membranes operating by reverse osmosis, possibly arranged in parallel .

[0030]. A first portion of purified liquid, called permeate, and a second portion of waste liquid are therefore obtained downstream of said second treatment station F, in which the impurities originally contained in the washing liquid are concentrated.

[0031]. Said waste portion is reintroduced by means of one or more return ducts 14 inside said collection tank A, mixing with the washing liquid present therein, increasing its concentration of impurities.

[0032]. The permeate, on the other hand, continues its path inside said recirculation circuit 100: flowing along a connecting duct 15, said permeate passes through a boiler G equipped with heating means suitable for heating it up to the desired washing temperature, advantageously of about 85 â € “90 ° C in order to guarantee a first sterilization of the liquid itself.

[0033]. Third pumping means H are then provided for withdrawing the liquid leaving said boiler G and sending it to a third treatment station I, in which disinfection means are provided which are suitable for reducing any bacteriological charge present in the liquid. Preferably, said disinfection means operate by exploiting ultraviolet rays. Advantageously, therefore, the treatment station I is located downstream from the treatment stations comprising filtering means, since, as known, the disinfection is more effective in the absence of suspended particles.

[0034]. Downstream of said third treatment station I, the recirculation circuit 100 is directly connected to said sprinkler means 11 to introduce a treated / purified liquid into said washing chamber L, endowed with chemical / physical and bacteriological characteristics such as to make it suitable re-use for a new phase or a new washing cycle.

[0035]. Advantageously, therefore, said washing chamber L, said collection tank A and said recirculation circuit 100 form a closed system, substantially watertight, in which the originally loaded washing liquid is used for a plurality of phases and cycles of subsequent washing without drawing further water supplies from the water mains and without introducing liquids into the sewer.

[0036]. The operation of the dishwashing machine 10 of the invention can therefore proceed by recycling the washing liquid both for several washing phases within a cycle, and also for countless consecutive washing cycles. In other words, the dishwashing machine 10 of the invention is substantially self-sufficient from the water point of view for a large number of washing cycles.

[0037]. Advantageously, a system for controlling one or more critical parameters can be provided inside the dishwasher 10: when at least one of the controlled parameters reaches a corresponding pre-set threshold value, the system generates a signal that warns of the need to eliminate, completely or even partially, the washing liquid saturated with impurities, replenishing it with clean water.

[0038]. To this end, a parameter suitable to be monitored can be identified, for example, in the time taken by a certain flow rate of liquid to pass through a treatment station: when in a certain time interval, the flow of washing liquid treated by said second treatment station F falls beyond a threshold value, the warning signal is generated.

[0039]. Another parameter that can be significant is for example the pH of the washing liquid inside the collection tank A, which can be detected by means of a special measuring device.

[0040]. The washing liquid loaded with impurities can therefore be evacuated, completely or partially, from the dishwasher 10 by moving the opening of said three-way valve C from said first operating position to said second operating position, which diverts the washing liquid passing through the circuit 100 discharging it outside, for example inside the municipal sewer M. This operation can be carried out manually by the user, following the warning signal issued, or carried out in an automated way.

[0041]. The operating procedure of a dishwasher 10 according to the invention comprises the following steps:

a) washing the dishes arranged in said washing chamber L with a previously loaded washing liquid;

b) collection of the washing liquid inside a collection tank A;

c) chemical and / or physical and / or bacteriological treatment of said washing liquid by passing it through a recirculation circuit 100 provided with one or more treatment stations;

d) introduction of the purified liquid in the previous phase c) inside said washing chamber L to carry out a subsequent washing.

[0042]. In particular, at the end of each washing cycle, the washing liquid is stored inside the collection tank A and, at the start of a new washing cycle, it is introduced into the recirculation circuit 100 where it is suitably treated. to make it suitable for use.

[0043]. Preferably, the main operating members of said dishwashing machine 10 can be operated, in a known way, by suitable command and control means, not shown.

[0044]. Obviously, a dishwashing machine is equipped with numerous other known devices which, not being directly relevant for the purposes of this invention, have been omitted.

[0045]. Finally, it is specified that the directional terms as used herein to describe the present invention, such as "above, below, vertical, horizontal, lower and upper", as well as any other similar directional term, must be interpreted with reference to a dishwasher 10 when in use.

[0046]. From the foregoing it is therefore evident that the present invention achieves the aims and advantages initially envisaged. In fact, a dishwasher machine 10 has been proposed which is able to minimize the consumption of water and electricity during its use, thanks to the reuse of the entire quantity of washing liquid initially loaded for several consecutive washing cycles. Therefore, after initially filling the collection tank A with clean water, no further water supplies from the water mains are necessary for a large number of subsequent washing cycles.

[0047]. Clearly, this objective is achieved while still guaranteeing a suitable degree of sanitation of the dishes to be washed, due to the use of one or more treatment stations arranged in such a way as to purify the washing liquid loaded with impurities from the previous washing cycle making it perfectly reusable for the new cycle.

[0048]. Furthermore, the use in at least one of said one or more treatment stations of filter media formed by semipermeable membranes operating by reverse osmosis in the recirculation circuit 100 is particularly advantageous: in fact, as the various washing cycles follow one another, the impurities removed from the dishes through the washing liquid they are progressively filtered into the recirculation circuit 100 and reintroduced into the collection tank A.

[0049]. Consequently, the concentration of impurities present in the liquid present in the collection tank A increases progressively, while the treated liquid, which is directly sprayed on the dishes, maintains its degree of purity substantially unchanged, unlike that shown in the known art.

[0050]. For this reason, therefore, the dishwasher of the invention can continue to use the same washing liquid for a very consistent number of washing cycles.

[0051]. It is therefore evident that a dishwashing machine according to the invention is particularly suitable for use in places where drinking water is a limited or rationed resource, for example due to drought, or in places where There is a connection with the municipal water and sewerage network, such as in military camps or built by civil protection in emergency situations. In the latter case, the initial water filling can be done using a top-up tank.

[0052]. Naturally, the present invention is susceptible of numerous applications, modifications or variations without thereby departing from the scope of protection, as defined by the attached claims.

[0053]. Furthermore, the materials and equipment used in the present invention, as well as the shapes and dimensions of the individual components, may be the most suitable according to specific requirements.

Claims (10)

DISHWASHER WITH RECYCLING THE WASHING LIQUID FOR SUBSEQUENT WASH " CLAIMS 1. Dishwashing machine (10) comprising - a washing chamber (L) equipped with sprinkler means (11) for a washing liquid, - a collection tank (A), in which said washing liquid is collected at the end of a washing cycle, said tank (A) being arranged below said washing chamber (L) and being communicating with it, - a recirculation circuit (100) for said washing liquid comprising one or more treatment stations (D, F, I), - pumping means being provided to give said washing liquid the pressure necessary to pass through said one or more treatment stations (D, F, I) in said recirculation circuit (100), characterized by the fact that said recirculation circuit (100) is connected on one side to said collection tank (A), on the other it is directly connected to said sprinkler means (11) to introduce the treated liquid into said washing chamber (L) from said one or more treatment stations (D, F, I). Dishwashing machine (10) according to claim 1, wherein said washing chamber (L), said collection tank (A) and said recirculation circuit (100) form a closed system, substantially watertight. Dishwashing machine (10) according to any one of the preceding claims, wherein at least one station (D, F) of said one or more treatment stations (D, F, I) comprises filtering means. Dishwashing machine (10) according to claim 3, wherein said at least one treatment station (F) comprises filtering means formed by semipermeable membranes operating by reverse osmosis, downstream of which a waste liquid is reintroduced into said collection tank (A), while the permeated liquid continues its path in said recirculation circuit (100). Dishwashing machine (10) according to claim 3, wherein said at least one treatment station (D) comprises filtering means formed by a microfilter. Dishwashing machine (10) according to claims 4 and 5, in which said microfilter is arranged upstream with respect to said semipermeable membranes. Dishwashing machine (10) according to any one of the preceding claims, wherein said recirculation circuit (100) further comprises a treatment station (I) in which disinfection means operating by using ultraviolet rays are provided. Dishwashing machine (10) according to any one of the preceding claims, wherein said recirculation circuit (100) further includes a boiler (G) comprising heating means adapted to give said treated liquid the desired temperature. Dishwashing machine (10) according to any one of the preceding claims, wherein said recirculation circuit (100) further comprises selective diverting means (C) for the washing liquid, said selective diverting means (C) being able to assume a first operating position, in which the washing liquid flows through said recirculation circuit (100), and a second operating position, in which the washing liquid is diverted towards a drain (M), the passage between said first operating position to said second operating position being operated in response to a signal generated by a control system adapted to monitor at least one control parameter, when said control parameter reaches a preset threshold value. 10. Washing process operable in a dishwashing machine (10) according to claim 1, comprising the following steps: a) washing the dishes arranged in a washing chamber (L) with a previously loaded washing liquid; b) collection of the washing liquid inside a collection tank (A); c) chemical and / or physical and / or bacteriological treatment of said washing liquid by passing it through a recirculation circuit (100) equipped with one or more treatment stations (D, F, I); d) direct introduction of the liquid purified in the previous phase into said washing chamber (L) for a subsequent washing.