WO2017052796A1

WO2017052796A1 - In-door dishwasher condenser system

Info

Publication number: WO2017052796A1
Application number: PCT/US2016/045630
Authority: WO
Inventors: Dino Chirumbolo
Original assignee: Illinois Tool Works Inc.
Priority date: 2015-09-22
Filing date: 2016-08-04
Publication date: 2017-03-30

Abstract

An in-door vent system provides an electric fan (32) directing a first portion of fresh air into the dishwasher cavity (12) to cause moist air to pass vertically downward through a condensation chimney. The condensation chimney has separating dividers (44,44') to promote condensation and to mix the moist air with a second portion of the fresh air from the electric fan (32). Condensate moisture drains out of the bottom of the chimney back into the washing cavity received by the dishwasher drain. A U-trap communicates with a venting exhaust opening (28) discharging cooler and drier air outside of the dishwasher.

Description

IN-DOOR DISHWASHER CONDENSER SYSTEM

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of US provisional application 62/221,771 filed September 22, 2015, and hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to automatic dishwashing machines (dishwashers) and in particular to dishwashers providing improved dish drying by convection air.

BACKGROUND OF THE INVENTION

[0003] Dishwashers, such as those found in many homes, provide a wash cavity holding one or more racks into which eating utensils and cookware may be placed for cleaning. The wash cavity may be sealed by a door opening at the front of the wash cavity to allow loading and unloading of the chamber. The door is closed during a washing cycle to prevent the escape of water sprayed within the volume of the wash cavity and used to wash items placed in the racks. Upon completion of the washing cycle, a drying cycle is initiated during which water is drained from the wash cavity and moist air is discharged through a vent. Cool air, pulled by convection or a fan into the chamber through a lower vent, dries the heated dishes.

[0004] The greater efficiency of recent designs in removing moisture from the wash cavity and contained dishes can create condensation problems when high humidity air is exhausted from the dishwasher and contacts cool surfaces, such as a metal -faced dishwasher door. This condensation may cause the undesirable collection of water on surfaces near the vent outlet.

[0005] US patent 7,909,939 issued March 22, 2011, and entitled Humidity Reducing Exhaust Duct for Dishwasher describes a chamber that can be used to receive high humidity air and that includes a condensing region to prevent the discharge of water-saturated air from the dishwasher and a reservoir for holding condensation to be dried later by continued operation of the fan. Moist air is drawn from the wash cavity through holes in a lower sidewall of the cavity and replaced with fresh air from holes in an opposite and higher sidewall of the cavity.

[0006] Recent dishwasher designs may employ a one-piece tub, for example, of stainless steel, which defines the wash cavity and, when closed by the door, is sealed from communication with the outside air. The sealed nature of this chamber makes the promotion of air circulation for proper venting particularly difficult.

SUMMARY OF THE INVENTION

[0007] The present invention provides a system for extracting humid air from a dishwasher after completion of washing and for condensing moisture from that air before it is released into the room. The system fits within the dishwasher door preventing the need to add additional holes to the one-piece dishwasher tub or communicating channels. As so positioned, condensed water may be returned to the wash cavity through the bottom of the door received by the drain of the dishwasher.

[0008] Specifically, the invention provides a humidity reducing dishwasher vent positionable within a door of the dishwasher. The vent includes a vent housing fitting in the door and providing a contiguous (intercommunicating) chamber having a fresh air intake opening and a venting exhaust opening, both of these openings being between the chamber and air outside of the dishwasher cavity. The chamber also provides a fresh air injection opening, a moist air reception opening and a drain opening, all three of these openings being between the chamber and the dishwasher cavity. An electric fan is positioned at the first air intake opening to draw fresh air outside of the dishwasher cavity into the chamber, and the vent housing provides a branch in the chamber directing a first portion of the fresh air out of the chamber through the fresh air injection opening and a second portion of the fresh air into a path between the moist air reception opening and the venting exhaust opening. The first portion of fresh air exiting the fresh air injection opening into the sealed dishwasher cavity causes moist air to flow inward into the chamber through the moist air reception opening to mix with the second portion of fresh air to condense moisture therefrom before flowing out of the venting exhaust opening.

[0009] It is thus a feature of at least one embodiment of the invention to provide a moisture reducing exhaust vent that can fit entirely in the door of the dishwasher eliminating the need to add openings to the dishwasher tub.

[0010] The drain opening may be positioned below the moist air intake opening when the door seals the dishwasher cavity to receive condensed moisture and direct the received condensed moisture back into the cavity.

[0011] It is thus a feature of at least one embodiment of the invention to eliminate the need to provide a separate drain to deal with condensed moisture. [0012] The drain opening may have a substantially higher resistance to airflow than the moist air reception opening so that more moist air flows into the moist air reception opening than into the drain opening.

[0013] It is thus a feature of at least one embodiment of the invention to reduce air inflow through the drain opening.

[0014] The drain opening may be partitioned by upwardly extending fingers obstructing a path from the moist air reception opening to the venting exhaust opening passing the drain opening.

[0015] It is thus a feature of at least one embodiment of the invention to minimize airflow past the drain opening that would reintroduce moist air into the vent air after condensation of the moist air from the moist air reception opening.

[0016] The air path between the fan and the fresh air injection opening may have a lower resistance to airflow than an air path between the fan and the moist air reception opening so that moist air flows into the moist air reception opening.

[0017] It is thus a feature of at least one embodiment of the invention to allow the use of a single fan to both introduce fresh air into the dishwasher cavity and to provide a source of fresh air mixing with the moist air within the vent to promote condensation while still ensuring that moist air is drawn into the vent.

[0018] The air path between the fan and the fresh air injection opening may have a length substantially less than a path between the fan and the moist air reception opening.

[0019] It is thus a feature of at least one embodiment of the invention to allow the fan to be positioned near the fresh air injection opening to provide the desired air resistance differentials while also separating the fresh air injection opening from the moist air reception opening for improved ventilation of the dishwasher cavity.

[0020] The vent housing may provide a continuously downwardly extending path from the fresh air injection opening to the drain opening to conduct water received through the fresh air injection opening to the drain opening.

[0021] It is thus a feature of at least one embodiment of the invention to provide a path of drainage for water splashed into the fresh air injection port during a wash cycle to eliminate the need for a cover or motor-operated door over the vent openings.

[0022] The vent may include a partition separating the fan from water entering the fresh air injection opening and separating the fan from the continuously downwardly extending path. [0023] It is thus a feature of at least one embodiment of the invention to provide a system where the fan is shielded from water splash, drainage and the passage of moist air through the fan.

[0024] The path between the moist air reception opening and the drain opening may be subdivided by multiple downwardly extending flow dividers directed along the path.

[0025] It is thus a feature of at least one embodiment of the invention to increase the surface area to which the moist air is exposed to promote condensation.

[0026] The flow dividers may provide separate serpentine flow paths.

[0027] It is thus a feature of at least one embodiment of the invention to increase the flow path length further increasing opportunities for condensation.

[0028] The second portion of fresh air may be received across the multiple flow dividers.

[0029] It is thus a feature of at least one embodiment of the invention improve the intermixing of fresh air with the received moist air to promote condensation.

[0030] The venting exhaust opening may be positioned at the bottom of the door. In one embodiment, the venting exhaust opening may be directed backward underneath the dishwasher.

[0031] It is thus a feature of at least one embodiment of the invention to provide a venting location that reduces possible condensation on the floor.

[0032] The vent housing may be molded thermoplastic material.

[0033] It is thus a feature of at least one embodiment of the invention to provide a venting system that can work with relatively low thermal conductivity materials that are nevertheless resistant to moisture and adaptable to the complex manufactured shapes.

[0034] The fresh air injection opening and moist air reception opening may provide a conduit with a conduit path extending upwardly as the conduit extends into the chamber to block spray received through the openings and return water of the spray to the dishwasher cavity.

[0035] It is thus a feature of at least one embodiment of the invention to reduce the introduction of water sprayed into the venting system during use of the dishwasher in the wash cycle to improve the ability of the venting system to extract water from moist air by retaining both its cool temperature and dry state during the venting cycle.

[0036] The venting exhaust opening may be separated from the moisture reception opening by a U-trap blocking condensed moisture from flowing out of the venting exhaust opening wherein the drain opening is positioned at a bottom of the U-trap. [0037] It is thus a feature of at least one embodiment of the invention to block condensed moisture from the venting exhaust opening for return of this moisture to the dishwasher cavity and the drain therein.

[0038] These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Fig. 1 is a perspective view of a wash cavity of a dishwasher showing the dishwasher housing and door when in the open position and showing an interior drain;

[0040] Fig. 2 is a perspective view of the inside of the door showing the fresh air injection opening, the moist air reception opening and lower condensate drain opening;

[0041] Fig. 3 a perspective view of the dishwasher of Fig. 1 with the door closed and a cover on the door removed to show a vent housing communicating among the openings within the door;

[0042] Fig. 4 is an elevational cross-section through the vent housing of Fig. 1 showing the paths of airflow;

[0043] Fig. 5 is a cross-section through the fresh air injection opening of the vent housing of Fig. 4 along line 5 - 5;

[0044] Fig. 6 is a figure similar to that of Fig. 5 showing the moist air reception opening of the vent housing of Fig. 4 in cross-section along line 6 - 6; and

[0045] Fig. 7 is a figure similar to that of Fig. 6 showing the condensate drain opening in cross-section along line 7 - 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODFMENT

[0046] Referring now to Fig. 1, a dishwasher 10 may include a wash cavity 12 into which dishes and cutlery may be placed for washing on racks 13. The wash cavity 12 may be defined by a generally rectangular tub 14, for example, of drawn stainless steel, providing a single piece, sealable volume open at the front to be covered by a door 16 having a dish-side surface 17 that seals against a front lip of the tub 14. A drain 15 may be positioned in the bottom of the wash cavity 12 for water to drain into a sewer line. Positioned within the dishwasher 10 but not shown are water control valves, a water pump, an optional water heater, and various spray mechanisms under the control of a controller board 19, for example, providing an electronic computer executing a stored program.

[0047] Referring now to Fig. 2, the dish-side surface 17 of the door 16 (when closed) may provide for a fresh air injection opening 18, a moist air reception opening 20 and a condensate drain opening 22 positioned, respectively, at the top right-hand edge of the dish- side surface 17 of the door 16, the top left-hand edge of the dish-side surface 17 of the door 16 and the bottom left-hand edge of the dish-side surface 17 of the door 16 as viewed in Fig. 2 and when the door 16 is closed. Each of the fresh air injection opening 18, moist air reception opening 20, and condensate drain opening 22 are in communication with the wash cavity 12 during the drying cycle.

[0048] Referring now to Figs. 3 and 4, a condenser system 24 may fit in the inner space of the door 16 to interconnect the fresh air injection opening 18, moist air reception opening 20, and condensate drain opening 22 to control airflow therebetween. Generally, the condenser system 24 provides for an enclosed housing 26 containing airflow between the fresh air injection opening 18, moist air reception opening 20, and condensate drain opening 22 in a single interconnected and hence contiguous chamber.

[0049] The housing 26 provides two additional openings in the form of an exhaust opening 28 and a fresh air inlet 25. The exhaust opening 28 projects rearward underneath the dishwasher 10 to prevent the discharge of residual moisture and heat directly toward a user standing in front of the dishwasher 10. The fresh air inlet 25 may pull fresh air from outside the wash cavity 12 through apertures (not shown) at various locations in the door 16 (not shown in Fig. 3) as removed from the exhaust opening 28.

[0050] Referring now specifically to Figs. 4 and 5, fresh air 27 may be drawn through the fresh air inlet 25 from the room outside of the wash cavity 12 by an electric fan 32 receiving power from the dishwasher controller during a drying cycle to pull fresh air into a fresh air chamber 30 within the housing 26. The fresh air chamber 30 communicates with fresh air injection opening 18. Pressure in the fresh air chamber 30 caused by the electric fan 32 exhausts fresh air 27 through the fresh air injection opening 18 into the wash cavity 12.

[0051] The fresh air chamber 30 communicates with the fresh air injection opening 18 by means of a short conduit 34 extending into the fresh air chamber 30 and curving upward by a height equal to the height of the fresh air injection opening 18. This conduit 34 serves to block the spray of water during the washing process from entering the fresh air chamber 30 and causes water so blocked to drain back down out into the wash cavity 12.

[0052] The fan 32 is positioned above the fresh air injection opening 18 to be removed from water draining downward from that opening and separated from the fresh air injection opening 18 by a partition 36 extending horizontally beneath the fan 32 and beyond the fan into the fresh air chamber 30. [0053] Referring momentarily to Fig. 6, air passing into the wash cavity 12 through the fresh air injection opening 18 pressurizes the wash cavity 12 forcing moist air from the wash cavity 12 to return into the housing 26 via moist air reception opening 20. This moist air 41 then passes downward through a chimney passageway 42. Air entering the moist air reception opening 20 communicates with the upper end of the chimney passageway 42 by means of a short conduit 34 extending into the chimney passageway 42 and curving upward by a height equal to the height of the moist air reception opening 20. This conduit 34 serves to block the spray of water during the washing process from entering the moist air reception opening 20 and causes water so blocked to drain back down out into the wash cavity 12.

[0054] A set of upper divider fingers 44 spaced apart horizontally extends downwardly from the moist air reception opening 20 to provide condensing surfaces on which moisture from air exhausted from the wash cavity 12 may condense. The upper divider fingers 44 may define a serpentine path to increase a path length of airflow along the cool walls of the divider fingers 44 increasing the opportunity for condensation. That condensed moisture may then drip in liquid form down to the bottom of the chimney passageway 42 to exit through the condensate drain opening 22. The upper divider fingers 44 may extend fully from the front to the rear surface of the condenser system 24 (when the door is in the vertical closed position) to fully channel the air within the chimney passageway 42 in a generally vertical downward direction and to maximize condensing surfaces.

[0055] The fresh air chamber 30 may communicate through a sidewall of the chimney passageway 42 through a diagonally downwardly extending fresh air diversion path 38 that connects to a vertically extending chimney passageway 42 at a point beneath the upper divider fingers 44. Vent housing 26 is constructed so that relative airflow resistance on a path from the fan 32 through the fresh air injection opening 18 compared to the air resistance through the fresh air diversion path 38 causes most fresh air 27 to exit the fresh air injection opening 18 but some fresh air 27' from the fresh air chamber 30 to follow fresh air diversion path 38 where it enters the chimney passageway 42 and serves to cool condensing surfaces within the chimney passageway 42 and to mix with moist air 41 in the condenser system 24 to promote precipitation of that moisture and to provide a momentum encouraging downward flow of the air through the chimney passageway 42.

[0056] A lower set of divider fingers 44' are positioned beneath the upper set of divider fingers 44 after a gap allowing distribution of the fresh air 27' among the passageways between each of the lower set of divider fingers 44'. These divider fingers 44' are serpentine to increase path length as described above and provide additional opportunities for condensation on their cool surfaces promoted by the cooling of the fresh air 27'.

[0057] As well as to conduct fresh air 27', the fresh air diversion path 38 allows any water entering the fresh air chamber 30 during the washing cycle to drain in a continuously downwardly extending path to the drain opening 22. From there, the water may pass the condensate drain opening 22 in the bottom of the wash cavity 12 to the dishwasher drain 15.

[0058] Referring also to Fig. 7, air restricting fingers 46 may extend upwardly behind the condensate drain opening 22 within the chimney passageway 42 of the condenser system 24 also providing condensing surfaces and discouraging airflow that might scavenge moisture at the bottom of the chimney passageway 42. These air restricting fingers 46 together with the size of the condensate drain opening 22 serve to promote air flow in through moist air reception opening 20 over any moist air flow inward through condensate drain opening 22. They also prevent sideways, scavenging airflow across the condensate drain opening 22. The condensate drain opening 22 is substantially flush with a bottom of the housing 26 to prevent the accumulation of water in the housing 26.

[0059] A branch passage 50 connects to one side of the chimney passageway 42 above the condensate drain opening 22 to provide an upward path of reduced-moisture exhaust air 52 out of exhaust opening 28. The branch passage 50 extends initially upwardly to provide sloping surfaces that will channel any additional condensation occurring in the first part of the branch passage 50 back toward condensate drain opening 22. In this respect, the bottom of the chimney passageway 42 at condensate drain opening 22 provides a U-trap structure tending to capture liquid moisture while allowing dryer non-condensing air to pass out of the exhaust opening 28.

[0060] After the upward portion, the branch passage 50 extends vertically downward to the exhaust opening 28.

[0061] The size of moist air reception opening 20 and condensate drain opening 22 and the constrictions provided by the air diversion path 38, divider fingers 44 and air restricting fingers 46 are such that pressure within the wash cavity 12 caused by the influx of fresh air through fresh air injection opening 18 preferentially causes airflow into moist air reception opening 20 and not into condensate drain opening 22 so that the majority of the air passes downward through the chimney passageway 42 and is thus exposed to a maximum area of condensing surface of condensing divider fingers 44. For this purpose the area of the condensate drain opening 22 may be minimized and its air-flow resistance maximized to allow the drainage of water with minimal air inflow.

[0062] It will be appreciated that the size and number and thermal mass of the divider fingers 44 may be adjusted to maximize the opportunity for moisture condensation within the condenser system 24 during a normal drying cycle and to promote the desired patterns of airflow.

[0063] The housing 26 and the divider fingers 44 may be generally constructed of a thermoplastic material for ready manufacturing.

[0064] Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. An in-door dishwasher vent positionable within a door of the dishwasher, the door closable to cover a dishwasher cavity for receiving dishes therein, the vent comprising: a vent housing fitting in the door and providing a contiguous chamber having a fresh air intake opening and a venting exhaust opening, both between the chamber and air outside of the dishwasher cavity, and a fresh air injection opening, a moist air reception opening and a drain opening, all three between the chamber and the dishwasher cavity; and

an electric fan positioned at the fresh air intake opening to draw fresh air outside of the dishwasher cavity into the chamber;

wherein the vent housing provides a branch in the chamber directing a first portion of the fresh air out of the chamber through the fresh air injection opening and a second portion of the fresh air into a path between the moist air reception opening and the venting exhaust opening; and

wherein the first portion of fresh air exiting the fresh air injection opening into the dishwasher cavity causes moist air to flow inward into the chamber through the moist air reception opening to mix with the second portion of fresh air to condense moisture therefrom before flowing out of the venting exhaust opening.

2. The in-door dishwasher vent of claim 1 wherein the drain opening is positioned below the moist air intake opening when the door seals the dishwasher cavity to receive condensed moisture and direct the received condensed moisture back into the cavity.

3. The in-door dishwasher vent of claim 2 wherein the drain opening has a substantially higher resistance to airflow than the moist air reception opening so that more moist air flows into the moist air reception opening than into the drain opening.

4. The in-door dishwasher vent of claim 3 wherein the drain opening is partitioned by upwardly extending fingers obstructing a path from the moist air reception opening to the venting exhaust opening past the drain opening.

5. The in-door dishwasher vent of claim 1 wherein an air path between the fan and the fresh air injection opening has a lower resistance to airflow than an air path between the fan and the moist air reception opening so that moist air flows into the moist air reception opening.

6. The in-door dishwasher vent of claim 1 wherein an air path between the fan and the fresh air injection opening has a length substantially less than a path between the fan and the moist air reception opening.

7. The in-door dishwasher vent of claim 1 wherein the vent housing provides a continuously downwardly extending path from the fresh air injection opening to the drain opening to conduct water received through the fresh air injection opening to the drain opening.

8. The in-door dishwasher vent of claim 7 including a partition separating the fan from water entering the fresh air injection opening and separating the fan from the continuously downwardly extending path.

9. The in-door dishwasher vent of claim 1 wherein a path between the moist air reception opening and the drain opening is subdivided by multiple downwardly extending flow dividers directed along the path.

10. The in-door dishwasher vent of claim 9 wherein the flow dividers provide separate serpentine flow paths.

11. The in-door dishwasher vent of claim 9 wherein the second portion of fresh air is received across the multiple flow dividers.

12. The in-door dishwasher vent of claim 1 wherein the venting exhaust opening is positioned at a bottom of the door.

13. The in-door dishwasher vent of claim 12 wherein the venting exhaust opening is directed backward underneath the dishwasher.

14. The in-door dishwasher vent of claim 1 wherein the vent housing is molded thermoplastic material.

15. The in-door dishwasher vent of claim 1 wherein the fresh air injection opening and moist air reception opening provide a conduit with a conduit path extending upwardly as the conduit path extends into the chamber to block spray received through the fresh air injection opening and moist air reception opening and return water of the spray to the dishwasher cavity.

16. The in-door dishwasher vent of claim 1 wherein the venting exhaust opening is separated from the moist air reception opening by a U-trap blocking condensed moisture from flowing out of the venting exhaust opening wherein the drain opening is positioned at a bottom of the U-trap.