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(11) | EP 3 797 668 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | HOOD-TYPE INDUSTRIAL DISHWASHER WITH DEVICE FOR CONTAINING STEAM AT THE END OF THE OPERATING CYCLE |
| (57) Hood-type industrial dishwasher comprising a fixed lower base with a rear wall (la)
extending upwards and on which is mounted a vertically movable hood (2) which is closed
on the sides, on the front and at the top but open on the rear side which is facing
the rear wall (la) and on the bottom side facing the base, the dishwasher also including
a fan (5) coupled to a diffuser (6) provided with an outlet slot (6a) which extends
in a horizontal plane over a width substantially equal to the internal width of the
hood (2) and is arranged so as to emit an air blade (8) which extends vertically on
the rear side of the hood (2).
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[0001] The present invention relates to hood-type industrial dishwashers, and in particular to a dishwasher provided with a device for containing the steam that is released by the machine upon opening at the end of the operating cycle.
[0002] It is known that an industrial dishwasher operates at high temperatures of the wash/rinse water that imply the generation of a significant amount of steam, therefore an inconvenience to the user is the significant release of steam when the dishwasher is opened at the end of the operating cycle. In order to overcome said drawback the dishwasher must include also a steam condenser located in an air recirculation circuit that provides the condensation of the steam prior to the opening of the dishwasher, so as to prevent it from being released in the environment with adverse effects on the operator and/or on other machines present in the room also due to the significant change in temperature and humidity.
[0003] Nonetheless, when the hood is raised at the end of the operating cycle, if there is no physical closure (wall) on the rear side of the hood, a small amount of residual steam present in the air inside the machine can escape, as well as the steam generated by the evaporation of the drops on the inside walls of the hood itself. Since on some models of hood-type dishwashers it is not possible to make such a rear closure, due to the construction solution adopted, this steam release is inevitable with the risk of condensation on the wall of the room or on another element adjacent to the dishwasher.
[0004] Therefore the object of the present invention is to provide a hood-type dishwasher that is free from said drawbacks. Said object is achieved by means of a hood-type dishwasher comprising a fan coupled to a diffuser so as to generate a vertical "air blade" that acts as the rear wall of the hood. Other advantageous features of this dishwasher are specified in the dependent claims.
[0005] The main advantage of the present dishwasher is that it minimises or even completely eliminates the rear steam release when the hood is raised at the end of the operating cycle.
[0006] A second major advantage of this dishwasher is that the steam containment device has a simple structure, which is economical to produce and install and requires no maintenance.
[0007] Further advantages and characteristics of the dishwasher according to the present invention will be evident to those skilled in the art from the following detailed description of two embodiments thereof with reference to the attached drawings, in which:
Fig.1 is a frontal perspective view of a first embodiment of a dishwasher according to the invention, with the hood in the open position;
Fig.2 is a frontal perspective view of the hood of the dishwasher of Fig.1, with a part of the top removed to show the location of the fan and the diffuser;
Fig.3 is a rear perspective view in vertical section of the hood of Fig.2; and
Fig.4 is a view similar to Fig.3 that shows a second embodiment of the aforesaid dishwasher.
[0008] Referring to the above figures, there is seen that a hood-type dishwasher according to the invention traditionally includes a fixed lower base 1 with a rear wall 1a extending upwards and on which a hood 2 is mounted through a handle 3 and two side rods 4 (only one visible in Fig.1), so that hood 2 is vertically mobile between a closed position where it rests on base 1 and an open position where it is raised with respect to base 1, as shown in Fig.1. The structure of hood 2 is closed on the front, at the top and on the sides, where the connecting rods 4 are pivoted, but it is open on the back side which is facing the rear wall 1a of base 1 and on the bottom side facing base 1.
[0009] The innovative aspect of this dishwasher, as mentioned above, lies in the presence of a steam containment device by means of a high speed air blade that extends vertically on the open rear side of hood 2 when it is raised at the end of the operating cycle. This containment device consists of a fan 5 coupled to a diffuser 6 provided with an exit slot 6a that extends in a horizontal plane over a width substantially equal to the internal width of hood 2.
[0010] More specifically, in the first embodiment illustrated in figures 1 to 3, fan 5 and diffuser 6 are arranged horizontally under the top wall 2a of hood 2, which is also preferably equipped along its side margins with two intake grilles 7 to increase the flow rate of the air sucked in by fan 5 and introduced into diffuser 6 to generate an air blade 8 that extends vertically from top to bottom coming out of the outlet slot 6a (as indicated by the arrows in Fig.3). Note that in order to limit the size of the containment device it is preferable to use a fan 5 of the tangential type, and that due to the horizontal arrangement of diffuser 6 it must end with a 90° curved portion in order to obtain an exit slot 6a arranged in a horizontal plane.
[0011] The flow rate and the speed of the air flow delivered by diffuser 6 are designed to obtain an air blade effective in containing steam with the minimum possible energy consumption and the minimum noise level. In this respect, the air speed at the outlet slot 6a is preferably at least 0,8 m/s.
[0012] In the second embodiment illustrated in Fig.4, the containment device is essentially the same but is housed in the rear wall 1a of base 1 instead of under the top wall 2a of hood 2, which is thus lighter. In this way, thanks to the vertical arrangement of diffuser 6 it does not require a 90° curved portion in order to obtain an exit slot 6a arranged in a horizontal plane, whereby it is simpler and more compact. In addition, the presence of a straight diffuser 6a results in a significant reduction of the pressure drop inside it, which allows fan 5 to use less power to generate an air blade 8 with the same flow speed as in the first embodiment.
[0013] Also in this case, it is preferable to provide at least one intake grille 7, which can be placed at the top of the rear wall la, as shown in Fig.4, or on one or both sides of said rear wall 1a to be closer to fan 5 (but in this case the dishwasher must be kept apart from elements arranged on its sides). Note that, obviously, in the second embodiment the air blade 8 extends vertically from the bottom to the top but has the same effectiveness in containing steam as in the first embodiment.
[0014] It is clear that the above-described and illustrated embodiments of the dishwasher according to the invention are only examples susceptible to numerous changes. In particular, the shape, size and arrangement of fan 5, diffuser 6 and grilles 7 can be varied according to manufacturing needs, as well as the type of fan 5, as long as the steam containment device is able to generate an effective air blade 8 on the rear side of hood 2.
1. Hood-type industrial dishwasher comprising a fixed lower base (1) with a rear wall
(1a) extending upwards and on which there is mounted a hood (2) that is vertically
mobile between a closed position where it rests on said base (1) and an open position
where it is raised with respect to the base (1), the structure of said hood (2) being
closed on the sides, on the front and at the top but open on the rear side which is
facing said rear wall (1a) and on the bottom side facing the base (1), characterized in that it further includes a fan (5) coupled to a diffuser (6) equipped with an outlet slot
(6a) that extends in a horizontal plane over a width substantially equal to the internal
width of the hood (2), said outlet slot (6a) being arranged so as to emit an air blade
(8) that extends vertically on said rear side of the hood (2).
2. Hood-type industrial dishwasher according to claim 1, characterized in that it further includes at least one intake grille (7) arranged in fluid communication
with the fan (5).
3. Hood-type industrial dishwasher according to claim 1 or 2, characterized in that the fan (5) is a tangential fan.
4. Hood-type industrial dishwasher according to any of the previous claims, characterized in that the fan (5) and the diffuser (6) are arranged horizontally under the top wall (2a)
of the hood (2), the diffuser (6) being provided with an end portion that curves at
90° downwards.
5. Hood-type industrial dishwasher according to claims 2 and 4, characterized in that it includes two intake grilles (7) arranged along the lateral edges of the top wall
(2a) of the hood (2).
6. Hood-type industrial dishwasher according to any of claims 1 to 4, characterized in that the fan (5) and the diffuser (6) are arranged vertically in the rear wall (1a) of
the base (1).
7. Hood-type industrial dishwasher according to claims 2 and 6, characterized in that it includes one or more intake grilles (7) placed at the top and/or on a side of
the rear wall (1a) of the base (1).
8. Hood-type industrial dishwasher according to any of the previous claims, characterized in that the fan (5) and the diffuser (6) are designed to generate an air flow such that the
air speed at the outlet slot (6a) is at least 0,8 m/s.