ES2717551B2 - Conveyor dishwasher machine equipped with an improved rinse device and associated method - Google Patents

Description

DESCRIPTION

Conveyor dishwasher machine equipped with an improved rinse device and associated method

Cross reference to correlated patent applications

This application claims the priority of Italian Patent Application No. 102017000148499 filed on December 21, 2017, the content of which is incorporated herein by reference.

The present invention relates to a conveyor dishwasher machine provided with an improved rinse device and an associated rinse method, which allows a considerable saving of energy and water, as well as the operational finishing fluids, in particular of the brightener.

The rack-conveyor machines, also known as tunnel type dishwashing machines, comprise a housing that delimits a tunnel chamber divided into different sectors or stations, arranged in sequence, to perform, in sequence, the different functions provided for prewash, wash, rinse and dry. The dishes to be cleaned are placed inside lattice baskets or trays that are transported through the different sections / different sectors by means of a belt conveyor, which crosses the entire tunnel chamber and has its opposite ends arranged outside the chamber tunnel, respectively upstream of an inlet opening and downstream of an outlet opening of the tunnel chamber, to allow the placement of the baskets containing the dirty dishes and the subsequent recovery of the same baskets, which contain the dishes washed and dried.

In order to respect the hygienic-sanitary standards, the final rinse of the dishes must be carried out with water carried at an elevated temperature, equal to or higher than 80 ° C, generally added with an operating finishing fluid, such as an agent rinse aid. In addition, the amount of rinse water must be proportional to the maximum feed rate of the conveyor belt, on which the productivity of the dishwashing machine depends. Consequently, taking into account that a dishwasher machine It works rarely at the maximum project speed, considerable wastes of rinse water and rinse aid are verified in dishwashing machines, with the consequent high energy consumption, due to excessive consumption of very hot water.

Finally, it has been found that some types of dishes, particularly those made of glass, can be damaged due to the thermal shock of very hot rinse water jets.

To solve these problems, document GB2435413A provides for the rinse section of a tunnel type dishwasher with several arms / nozzles, some of which are selectively deactivated depending on the speed of advance of the conveyor belt.

This solution is not without problems. First, it considerably complicates the construction and, above all, the operation of the dishwasher, requiring the introduction of sophisticated control systems, which also significantly increase production costs. Secondly, the deactivation of the rinse nozzles / arms can cause, over time, their clogging due to deposits, in particular if hard water is used, which forces the adoption of systems to reduce water hardness, which Again it implies an increase in cost. Finally, this solution does not solve the problem of damage to dishes due to thermal shocks.

The object of the invention is to provide a tunnel type dishwashing machine, that is, a conveyor dishwashing machine, which allows reducing energy consumption and finishing chemicals such as brightener, while avoiding thermal shocks to the dishes, while ensuring compliance with hygienic and sanitary standards. It is also an object of the present invention to provide a dishwashing machine of the type mentioned above, which is of simple and economical construction and, above all, of simple operation, which does not require the introduction of additional control systems.

Finally, it is an object of the present invention to provide a rinsing method that allows to overcome or at least reduce the drawbacks of the prior art.

According to the present invention, therefore, a conveyor dishwashing machine and an associated rinsing method are provided in accordance with what is defined in the appended claims.

Other objects and advantages of the present invention will be clear from the following description of some of its non-limiting embodiments, provided purely by way of example and with reference to the figures in the accompanying drawings, in which:

- Figure 1 schematically illustrates a longitudinal elevation view and sectioned by means of a vertical section plane of a dishwasher machine with conveyor, or of a "tunnel" type, made in accordance with the present invention; Y

- Figures 2 and 3 schematically illustrate the same view in longitudinal elevation and in cross-section through a plane of vertical section of the respective possible variants of the dishwashing machine shown in Figure 1.

With reference to Figure 1, a dishwasher machine with conveyor, or of the so-called "tunnel" type, of typically professional use (ie designed for intensive use in public environments such as restaurants, is indicated as a whole). bars, communities), illustrated only in schematic mode for simplicity, in its essential components.

The dishwashing machine 1 comprises a housing 2, shown schematically only in longitudinal section by a line that delimits its outer profile. The housing 2 defines, in its own interior, a tunnel chamber 3.

The tunnel chamber 3 is subdivided into a plurality of stations or sections arranged in sequence; In the non-limiting example illustrated, the tunnel chamber 3 is subdivided into four stations: a prewash station 4, known, a wash station 5, known, a rinse station 6 and a drying station 7, known, which can to be or not to be part of the tunnel chamber 3, being in some machines only intended as an option.

According to one aspect of the present invention, regardless of the number and type of stations in which the tunnel chamber 3 is separated, the dishwasher 1 always It comprises at least one rinse station 6 arranged, immediately, downstream of a washing station 5 and upstream, when present, of a drying station 7.

The dishwashing machine 1 further comprises a conveyor 8 that passes through the tunnel chamber 3 to transport through it a plurality of known baskets (or lattice trays) 9 (one of them shown schematically in broken lines, for simplicity, in Figure 1), in which dishes 10 to be washed are received. The conveyor 8 can be of any known type normally used in tunnel machines of the type of the dishwasher 1, preferably it is a so-called "drag" conveyor, in which the trawl system of the baskets 9 is completely inside the machine 1 ; however, it could also be the type of tape; in any case, the conveyor 8 is of known type and, therefore, is not described in detail for simplicity.

Now and then the terms "upstream" and "downstream" should be understood with reference to a forward direction D of the conveyor 8, indicated in Figure 1 by the arrow.

The opposite ends 11 and 12 of the conveyor 8 are arranged in correspondence with the opposite openings 13 and 14 of, respectively, the entrance and exit of the tunnel chamber 3. In the non-limiting example illustrated, the opposite ends 11 and 12 of the conveyor 8 they are arranged inside the tunnel chamber 3, respectively, immediately downstream of the inlet opening 13 inside the tunnel chamber 3 and immediately upstream of the outlet opening 14 from the tunnel chamber 3, to allow easy positioning manual baskets 9 containing dirty dishes 10 and subsequent easy manual removal of the same baskets 9, containing dishes 10 washed and dried. Optionally, the introduction and removal of the baskets 9 can be automated by means of suitable known accessories.

In the case of a conveyor belt, not illustrated, however, the ends 11 and 12 are generally disposed outside the tunnel chamber 3, respectively, immediately upstream of the inlet opening 13 in the tunnel chamber 3 and immediately flow below the outlet opening 14 of the tunnel chamber 3.

In any case, the stations 4, 5, 6 and 7 are separated from each other by respective tilting bulkheads 16 made of a soft and flexible material, but in any case heat resistant, for example, in a synthetic plastic resin or adapted rubber.

Within the tunnel chamber 3, in correspondence with each station 4, 5, 6, respective supply arms 18-20 of a washing and / or rinsing fluid are arranged, which may consist of simple water or water with the addition of substances chemicals, for example, as detergents or finishing agents, such as a brightener. The arms 18 20 are generally present in pairs, arranged above and below the plane of the conveyor 8 on which the baskets 9 rest.

The prewash and wash stations 4 and 5 operate in a closed cycle, whereby the washing fluid used is collected in the appropriate tanks 21 and recirculated to the supply arms 18 by pumps 22. The latter, together with the tanks 21 and A motor 23 driving the conveyor 8 is housed inside the housing 2, below the tunnel chamber 3.

According to one aspect of the present invention, the rinse station 6 is provided with two pairs (or two groups) of rinse arms 19 and 20 of a rinse fluid, arranged in the tunnel chamber 3 inside the rinse station 6. In particular, the rinse section 6 is provided with at least one pair of first supply arms 19 and at least a couple of second supply arms 20; it is clear that arms 19 and 20 may be present in a number greater than two, for example, in groups of three or four, for example, two arms 19 and two arms 20 arranged at the top and bottom and others two arms 19 and 20 arranged on the side.

According to the present invention, the second supply arms 20 are always arranged, however, in the tunnel chamber 3 downstream of the first supply arms 19, wherein the terms "upstream" and "downstream" should be understood with reference to the feed direction D of the conveyor 8, as indicated above.

Finally, the dishwashing machine 1 comprises a hydraulic circuit 24 for supplying running water to the supply arms 19 and 20. In fact, unlike known stations 4 and 5, the rinse station 6 must operate in an open cycle and, for Therefore, it must be fed continuously with running water. Rinse fluid used is collected, unloaded and treated in a known way and not illustrated for simplicity.

According to the present invention, the hydraulic supply circuit comprises a receiving section 25 of running water and a first and a second fork, indicated respectively with references 26 and 27, connected to each other in parallel downstream of the receiving section 25 of running water, where for the hydraulic circuit 24 the terms "upstream" and "downstream" should be understood with reference to a flow direction F of the running water in the hydraulic supply circuit 24, indicated by the arrow.

The first branch 26 is hydraulically connected directly to the first arms 19 and the second branch 27 is hydraulically connected directly to the second arms 20.

In the embodiment illustrated in Figure 1, the reception section 25 of the hydraulic circuit 24 is constituted by a simple coupling to a pressurized tap water supply system, which is not illustrated for simplicity, for example, water conduction pubic, so it is not necessary to provide a feeding pump for the arms 19, 20.

According to one of the main aspects of the invention, in addition, the first branch 26 is hydraulically provided in series with a first boiler 28 for heating the main water arranged upstream (with reference to the flow direction F) of the first supply arms 19 ; similarly, the second branch 27 is hydraulically provided in series with a second boiler 29 for heating the upstream stream water (with reference to the flow direction F) of the second supply arms 20.

According to the present invention, the first boiler 28 is established, that is, configured to heat the running water to a first preset temperature T1, while the second boiler 29 is established, that is, configured, to heat the running water to a second preset temperature T2, higher than the first preset temperature T1.

According to the present invention, the first preset temperature T1 is less than 80 ° C, while the second preset temperature T2 is greater than 80 ° C.

In particular, the first temperature T1 is higher than the wash water supply temperature in the wash section 5. For example, the temperature of the wash fluid supplied in section 5 by the arms 18 is usually about 60 ° C; in this case, the temperature T1 will be chosen slightly higher, for example, equal to 70 ° C.

Instead, the temperature T2 will be chosen well above the washing temperature and greater than at least a dozen degrees at the temperature T1, for example, the temperature T2 is set equal to 85 ° C. In this way, it complies with hygienic and sanitary standards without causing a thermal shock in the dishes 10.

Furthermore, according to an additional and non-secondary aspect of the present invention, the hydraulic supply circuit 24 is configured so that the first and second arms 19 and 20 always supply the rinse fluid simultaneously.

In this way, a correct amount of rinse fluid is always guaranteed, regardless of the feed speed of the conveyor 8, without the need to install expensive and sophisticated control systems, but at the same time, thanks to the presence of two boilers separated 28 and 29 connected to supply arms 19 and 20 separated and adjusted to significantly different temperatures, the energy consumption of the dishwasher 1 is significantly reduced, since most of the water used for rinsing is heated to a lower temperature.

According to a further and non-secondary aspect of the present invention, finally, only the second branch 27 is connected by branch, upstream of the second arms 20 (always with reference to the flow direction F) with a supply device 30 of a rinse finish chemical to mix it with the running water supplied to the second arms 20.

According to a possible variant, illustrated in broken lines in Figure 1, the receiving section of the running water 25 of the hydraulic circuit 24 for feeding the arms 19, 20 comprises a non-return valve 31 arranged in series with a first tubular conduit 32 which is also part of the receiving section 25, whose tubular conduction 32, flow up the non-return valve 31 (with reference to the flow direction F) is directly connected to the running water and flow down the non-return valve 31 is directly connected with the first branch 26 and with the second branch 27, in branch both from the first tubular conduit 32 and towards the respective first boiler 28 and the second boiler 29.

In all cases, the delivery device 30 of a rinse finish chemical is a device for supplying a brightening agent and comprises a storage tank of a brightening agent 33, a tubular conduit of the brightening agent 34, which is fed into the storage tank 33, and a brightening agent supply pump 35 arranged in series in the tubular conduit 34 immediately downstream of the storage tank 33; the tubular supply line of the brightening agent 34 is carried out so that it preferably flows into the second boiler 29, downstream of the supply pump of the brightening agent 35. In this way, a good mixture of the brightening agent is ensured with the running water and a homogeneous heating of both (water and brightening agent) before the supply to the arms 20 and, therefore, to the dishes 10.

Figures 2 and 3 illustrate dishwashing machines 1b and 1c according to the present invention, made according to the possible variants to the embodiment illustrated in Figure 1. Details similar or identical to those already described are indicated by the same reference numbers , For simplicity.

First, the dishwashing machines according to the present invention illustrated in Figures 2 and 3 differ from the embodiment of Figure 1 in that the receiving water section 25 of the hydraulic supply circuit 24 of the arms 19 and 20 , it comprises a first tubular conduit 32 connected directly with the running water, a tubular conduit 36 arranged downstream of the first tubular conduit 32 and a known air blowing device 37, arranged in series with the first tubular conduction 32 and upstream of the tubular conduit 36 for decoupling the second tubular conduit 36 from the first tubular conduction 32.

In the embodiment of Figure 2, the second tubular conduit 36 of the dishwasher 1b is also hydraulically provided in series with a single feed pump 38 for both the first arms 19 and the second arms 20. The pump only 38 is necessary, since the air blowing device 37 restores the network pressure, so it is necessary to pressurize the running water again to be able to make it move in the hydraulic circuit 24 and to supply a pressure rinsing fluid of the arms 19 and 20.

The second tubular conduit 36 is connected directly, downstream of the single feed pump 38, with the first branch 26 and with the second branch 27, which both diverge bypass from the second tubular conduit 36 and to the respective first boiler 28 and the second boiler 29.

Preferably, and always with reference to Figure 2, the second tubular conduit 36, downstream of the single feed pump 38 for both pairs or groups of arms 19 and 20, and upstream of the first branch 26 and the second branch 27 is hydraulically connected in series with at least one heat exchanger 39 (in Figure 2, the heat exchangers 39 are two, arranged hydraulically in series in tubular conduction 36) that receive thermal energy through at least one circulating fan of hot air 40 from any one (or more than one) of stations 4, 5, 6 and, when present, also from the drying station 7. More specifically, the fan 40 attracts a flow of hot air A of one or more (depending on how the hydraulic connections are made inside the housing 2) of the sections or stations 4-7 located (with respect to the direction D) downstream of the fan 40 and the exchangers 39, which are therefore traversed by said flow of hot air A, which therefore gives part of its heat to the running water before being discharged from the machine 1.

With reference now to the variant of Figure 3, also in this case the receiving section 25 of running water comprises the tubular conduits 32, 36 and the air blowing device 37.

In this case, however, the second tubular conduit 36 is directly connected with the first branch 26 and with the second branch 27, which both deviate from the second tubular conduit 36 and to the respective first boiler 28 and second boiler 29 .

In addition, a first feed pump 41 is hydraulically arranged in series along the first branch 26 and a second feed pump 42 is hydraulically arranged in series along the second branch 27, in both cases downstream of the second tubular conduit 36 and flow up the first and second boiler 27, 28 (always with reference to the flow direction F), to feed the first arms 19 and the second arms 20, respectively.

Preferably, also according to this variant, the first branch 26 and / or the second branch 27 (preferably both, as illustrated in Figure 3) are hydraulically connected in series, respectively downstream of the pumps 41, 42 and upstream of the boilers 28, 29, at least one heat exchanger 39 that receives thermal energy through at least one air circulation fan 40 from one of the stations 4-7, as already described for the variant of Figure 2. In particular, the branch 26 is provided in series with a single heat exchanger 39, while the branch 27 is provided in series with two heat exchangers 39 placed in series with each other and arranged upstream of the heat exchanger 39 in series with the branch 26, with reference to the direction of a flow of hot air A attracted by the fan 40.

On the basis of the above, it is evident that all the conveyor dishwashing machines 1, 1b and 1c described carry out a rinse method to rinse dishes 10 present in the dishwasher machines themselves, in which a rinse fluid is supplied by the respective arms 19, 29 towards the dishes 10 which are contained in the respective baskets 9 advanced through the dishwasher 1, 1b, 1c from a conveyor 8.

According to the present invention, the rinsing method performed by dishwashing machines 1, 1b, 1c, comprises the following phases:

a) predispose, in a rinse station 6 of the dishwasher machine, separate pairs or groups of first arms 19 and second arms 20 supplying a rinse fluid, the second arms 20 being arranged downstream of the first supply arms 19 with reference to a feed direction D of the conveyor 8;

b) receiving running water and supplying it under pressure (at the network pressure in accordance with the embodiment of Figure 1, by means of pumps 38, 41,42 in the embodiments of Figures 2 and 3) within a first branch 26 and a second branch 27 of a hydraulic circuit 24 for feeding the arms 19, 20, the branches 26 and 27 being directly connected, respectively, with the first arms 19 and with the second arms 20, so that they simultaneously feed the first arms 19 and the second arms 20;

c) heating the running water, before supplying the arms 19, 20, respectively with a first preset temperature T1 in a first boiler 28 hydraulically arranged in series in the first branch 26, and with a second preset temperature T2, higher than the temperature T1, in a second boiler 29 hydraulically arranged in series on the second branch 27;

d) mix, upstream of the second arms 20, only the hot water heated in the second boiler 29, with a rinse finish chemical.

With reference to the variants of Figures 2 and 3, the rinsing method, according to the present invention, further comprises the phase of preheating the running water before supplying it in the first boiler 28 and / or the second boiler 29 by means of the less a heat exchanger 39 to which hot air is supplied from one of the stations 4-7 of the dishwasher.

Obviously, the flow A of hot air attracted by the fan 40 to pass through the heat exchangers 39 can obtain thermal energy not only from that entering stations 4-7, but also from that emitted by the entire dishwasher 1, 1b, 1c, for example, by passing the air in cavities located around the tunnel chamber 3.

Thanks to what has been described above, it is guaranteed at the same time to obtain the rinse as required by the hygienic-sanitary norms and with a great abundance of water, for an optimal result, and to save a large amount of thermal energy and polishing agent, since only a fraction of the rinse water is heated at high temperature and added with a brightening agent.

In this way, all objects of the present invention are achieved.

Claims (12)

1. Conveyor dishwasher machine (1, 1b, 1c) comprising: a housing (2) defining a tunnel chamber (3) subdivided into a plurality of stations or sections arranged in sequence, among which at least one station of rinse (6) placed immediately downstream of a washing station (5); a conveyor (8) passing through the tunnel chamber to transport through it a plurality of baskets (9) in which dishes (10) to be washed are received, with opposite ends (11, 12) of the conveyor being arranged, respectively, in correspondence with an inlet opening (13) in the tunnel chamber and an outlet opening (14) from the tunnel chamber, to allow the positioning of the baskets containing dirty dishes and the subsequent extraction of the same baskets, which contain washed dishes; the respective arms (19, 20) supplying a rinse fluid disposed in the tunnel chamber (3) within the rinse station (6); and a hydraulic circuit (24) for supplying running water to the supply arms; where: i) the rinse section (6) is provided with first supply arms (19) and second supply arms (20), the second supply arms (820) being arranged in the tunnel chamber downstream of the first supply arms (19) with reference to a feed direction (D) of the conveyor (8); characterized by the fact that, in combination: ii) the hydraulic supply circuit (24) comprises a receiving section of running water (25) and a first branch (26) and a second branch (27) connected to each other in parallel downstream of the receiving section (25) of running water with reference to a flow direction (F) of the running water in the hydraulic supply circuit, the first branch (26) being hydraulically connected only to the first arms (19) and the second branch (27) hydraulically connected only to the second arms (20); iii) the first branch (26) is provided with a first boiler (28) of the heating of the running water arranged upstream of the first supply arms (19) and the second branch (27) is provided with a second boiler (29) for heating the running water arranged upstream of the second supply arms (20); iv) the first boiler (28) is set to heat the running water to a first preset temperature (T1) and the second boiler (29) is set to heat the running water to a second preset temperature (T2) higher than the first; Y v) only the second branch (27) is connected by branch, upstream of the second arms (20), with a device (30) supplying a rinse finish chemical to mix it only with the running water supplied to the second arms (20). 2. Dishwashing machine according to claim 1, characterized in that the first preset temperature (T1) is below 80 ° C, while the second preset temperature (T2) is above 80 ° C. 3. Dishwashing machine according to claim 2, characterized in that the first temperature (T1) is higher than a washing water supply temperature in said washing section (5). 4. Dishwashing machine according to one of the preceding claims, characterized in that said supply device (30) for a rinse finish chemical is a device for supplying a brightening agent comprising a storage tank (33) for polishing agent, a tubular conduit (34) for supplying the brightening agent that is introduced into the storage tank (33), and a brightening agent supply pump (35) arranged in series with the tubular conduit (34) for supply, immediately flow down the storage tank (33); with the tubular supply line (34) of the brightener agent flowing into the second boiler (29), downstream of said brightener agent supply pump (35). 5. Dishwashing machine according to one of the preceding claims, characterized in that said hydraulic supply circuit (24) is configured such that the first (19) and the second (20) arms supply the rinse fluid, of simultaneously. 6. Dishwashing machine according to one of the preceding claims, characterized in that the receiving section (25) of the running water of said circuit Hydraulic feed comprises a non-return valve (31) arranged in series with a first tubular conduit (32), which, upstream of the non-return valve is directly connected to the running water and downstream of the non-valve Return is directly connected to the first and the second branch (26, 27), which both deviate from the first tubular conduit and to the respective first and second boilers (28, 29). 7. Dishwashing machine according to one of the preceding claims, characterized in that the receiving section (25) of the running water of said hydraulic supply circuit (24) comprises a first tubular conduit (32) directly connected to the running water , a second tubular conduit (36) arranged downstream of the first tubular conduit, and an air blowing device (37) arranged in series with the first tubular conduit and upstream of the second tubular conduit to decouple the second tubular conduction from the first tubular conduction; the second tubular conduit (36) being hydraulically provided in series with a single feed pump (38) for both first and second arms (19, 20) and being directly connected, downstream of said single feed pump (38), with the first and with the second branch (26, 27), which both deviate bypass from the second tubular conduit (36) and to the first and second boilers (28, 29), respectively. 8. Dishwashing machine according to claim 7, characterized in that the second tubular conduit (36) flows down said single feed pump (38) and flows up the first and second branches (26, 27) It is hydraulically connected in series to at least one heat exchanger (39) that receives thermal energy through at least one air circulation fan (40) of one or more of said plurality of stations or sections arranged in sequence. 9. Dishwashing machine according to one of the preceding claims, characterized in that the receiving section (25) of the running water of said hydraulic supply circuit (24) comprises a first tubular conduit (32) connected directly with the running water , a second tubular conduit (36) arranged flow under the first tubular conduit, and an air blowing device (37) arranged in series with the first tubular conduit and flow up the second tubular conduit to decouple the second conduction from the first driving; being the second tubular conduit (36) connected directly with the first and second branches (26, 27), which both deviate bypass from the second tubular conduit (36) and to the first and second boilers (28, 29), respectively; a first and a second feed pump (41, 42) are arranged hydraulically in series respectively along the first and second branch (26, 27), downstream of the second tubular conduit (36) and upstream of said first and second boilers (28, 29), to feed respectively the first and second arms (19, 20). 10. Dishwashing machine according to claim 9, characterized in that the first and / or the second branch (26, 27) are hydraulically connected in series, respectively, downstream of the first (41) and the second (42 ) pump and flow up of the first and second boilers (28, 29), and at least one heat exchanger (39) that receives thermal energy through at least one air circulation fan (40) from one or more of said plurality of stations or sections arranged in sequence. 11. Rinsing method for rinsing dishes present in a dishwasher machine (1, 1b, 1c) of conveyor, in which a rinsing fluid is supplied from the respective arms (19, 20) to the dishes that are contained in the baskets respective (9) advanced through the dishwasher by a conveyor (8); characterized by understanding the following phases: a) dispose in a rinse station (6) of the dishwashing machine, first (19) and second (20) supply arms of a rinse fluid, the second supply arms (20) being arranged downstream of the first supply arms (19) with reference to a feed direction (D) of the conveyor; b) receive running water and supply it under pressure within a first (26) and a second (27) branches of a hydraulic circuit directly connected, respectively, with the first (19) and second (20) arms, so that the first and second arms are fed simultaneously; c) heating the running water, before supplying said first and second arms, respectively with a first preset temperature (T1) in a first boiler (28) hydraulically arranged in series on the first branch (26), and a second preset temperature (T2), higher than the first, in a second boiler (29) hydraulically arranged in series on the second branch (27); d)

Mix, upstream of the second arms (20), only the running water heated in the second boiler (29) with a rinse finish chemical. 12.

Method according to claim 11, characterized in that it further comprises the phase of preheating the running water before feeding it into the first and / or the second boiler (28, 29) by means of at least one heat exchanger (39) towards which is fed hot air from one or more of said plurality of stations of the dishwasher.