Device for managing condensate drainage in cooling air duct systems

Abstract

A return air duct and a return air duct grille for a cooler in an aircraft galley, the return air duct grille having hinged slats that are biased to open during a cooling cycle and biased to close during a defrost cycle. In the closed orientation, the hinged slats transfer all condensate from the cooler to a collection hose. In the open orientation, the hinged slats allow unrestricted airflow. The hinged slats may include a passive biasing element to bias the hinged slats into an open orientation or a closed orientation as desired. The return air duct may also include a return air duct grille without hinged slats to allow unimpeded airflow when the hinged slats are in the closed orientation.

Description

Technical Field

[0001] The invention relates to a return air duct and a return air duct grille for a cooler in an aircraft galley. Background Art

[0002] In many commercial airliner galleys with cooled trolley compartments, the cold air is supplied by vapor cycle air coolers or coolant-fed air cooling units. During cooling, moisture condenses on the evaporator and / or heat exchanger. Ice formation occurs where food storage regulations require that the temperature of the trolley compartment be maintained between 0°C (32°F) and 4°C (39.2°F), severely restricting air flow through the cooler.

[0003] To defrost the heat exchanger and remove excess moisture, the circulating air is reversed (sometimes the cooling medium in the heat exchanger is reversed), and the moisture is blown out as condensate to be discharged into the aircraft's wastewater system.

[0004] The effectiveness of reversing the air flow depends on the type of cooling unit, its location relative to the kitchen structure, and the design of the cooling air distribution ductwork. Air cooling units designed to be mounted in the cart compartment (which are usually mounted on the back wall of a double bay together with the air distribution ductwork) cannot use a drip pan to handle condensation because placing the drip pan directly below the heat exchanger to collect condensation would severely restrict airflow. In this case, the return air duct collects all the water discharged during defrost; however, when the air flow is reversed, water droplets can be sprayed out of the air inlet grille of the return air duct and then reabsorbed during the next cooling cycle.

[0005] The amount of moisture built up in the cooling compartment may exceed the ability of the condensate drainage system to remove it in a single defrost cycle, resulting in water accumulation in the cart compartment. Summary of the invention

[0006] In one aspect, embodiments of the inventive concepts disclosed herein relate to a return air duct and a return air duct grille for a cooler in an aircraft galley, the return air duct grille having hinged slats that are biased to open during a cooling cycle and biased to close during a defrost cycle. In the closed orientation, the hinged slats transfer all condensate from the cooler to a collection hose; in the open orientation, the hinged slats allow unrestricted airflow.

[0007] In another aspect, the hinged slat includes a passive biasing element to bias the hinged slat into an open orientation or a closed orientation as desired.

[0008] In another aspect, the return air duct further includes a return air duct grille without hinged slats to allow unobstructed airflow when the hinged slats are in a closed orientation.

[0009] It should be understood that the foregoing general description and the following specific embodiments are only exemplary and explanatory and should not limit the scope of the claims. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the inventive concept disclosed herein and are used together with the general description to explain the principles. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] By referring to the accompanying drawings, those skilled in the art may better appreciate the numerous advantages of the embodiments of the inventive concepts disclosed herein.

[0011] Figure 1 shows a perspective view of a cooler for use with an embodiment of the inventive concepts disclosed herein;

[0012] Figure 2A shows a perspective view of a galley cart compartment including an embodiment of the inventive concepts disclosed herein;

[0013] Figure 2B shows a perspective view of a galley cart compartment including an embodiment of the inventive concepts disclosed herein;

[0014] Figure 3A shows a perspective view of a cooler and an intake duct including an embodiment of the inventive concepts disclosed herein;

[0015] Figure 3B shows a perspective view of a cooler and an intake duct including an embodiment of the inventive concepts disclosed herein;

[0016] Figure 4 shows a perspective view of a return air duct grill according to an exemplary embodiment of the inventive concepts disclosed herein;

[0017] Figure 5 A partial perspective view of a return air duct grill according to an exemplary embodiment of the inventive concepts disclosed herein is shown. DETAILED DESCRIPTION

[0018] Before explaining in detail at least one embodiment of the inventive concept disclosed herein, it should be understood that the inventive concept is not limited to the details of the construction and arrangement, steps or methods of the components described in the following description or shown in the accompanying drawings in terms of its application. In the following specific description of the embodiments of the inventive concept, many specific details are described in order to provide a more thorough understanding of the inventive concept. However, for those of ordinary skill in the art who benefit from the present disclosure, it will be apparent that the inventive concept disclosed herein can be practiced without these specific details. In other examples, well-known features may not be described in detail to avoid unnecessarily complicating the present disclosure. The inventive concept disclosed herein can be other embodiments, or can be practiced or executed in various ways. Similarly, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered restrictive.

[0019] When used herein, a letter following a reference number is intended to indicate an embodiment of a feature or element that may be similar but not necessarily identical to a previously described element or feature with the same reference number (e.g., 1, 1a, 1b). Such shorthand notation is used merely for convenience and should not be construed as limiting the inventive concepts disclosed herein in any way unless expressly indicated to the contrary.

[0020] In addition, unless expressly stated to the contrary, "or" refers to an inclusive or rather than an exclusive or. For example, any of the following satisfies condition A or B: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0021] In addition, the use of "a" and "an" is used to describe the elements and components of the embodiments of the present invention. This is done only for convenience and to give a general meaning of the present invention, and "a" is intended to include one or at least one, and the singular also includes the plural, unless it is obvious that it means otherwise.

[0022] Finally, when used herein, any reference to "one embodiment" or "some embodiments" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the inventive concept disclosed herein. The appearances of the phrase "in some embodiments" in various places in the specification do not necessarily all refer to the same embodiment, and embodiments of the disclosed inventive concept may include: one or more of the features explicitly described or inherently present herein, or any combination of subcombinations of two or more such features, as well as any other features that may not necessarily be explicitly described or inherently present in the present disclosure.

[0023] Broadly, embodiments of the inventive concepts disclosed herein relate to a return air duct and a return air duct grille for a cooler in an aircraft galley, the return air duct grille having hinged slats that are biased open during a cooling cycle and biased closed during a defrost cycle. In the closed orientation, the hinged slats transfer all condensate from the cooler to a collection hose; in the open orientation, the hinged slats allow unrestricted airflow.

[0024] Reference Figure 1 , a perspective view of a cooler 100 for use with an embodiment of the inventive concepts disclosed herein is shown. The cooler 100 includes an air outlet 102 disposed on a top surface and an air inlet 104 disposed on a bottom surface. During normal operation, the cooler 100 can operate in a cooling cycle, wherein air is drawn through the air inlet 104, cooled within the cooler 100, and discharged from the air outlet 102 to cool the surrounding space or any area to which the cooling air is ducted. In a defrost cycle, the air flow is reversed so that air is drawn through the air outlet 102 and discharged through the air inlet 104. Since frost in the cooler 100 comes from ambient moisture, the air drawn back through the air outlet 102 during defrost is typically drier than the air that initially caused the frost, and therefore does not significantly cause frost. When the air inlet 104 is disposed on the bottom surface, at least some of the condensate melted by the heat exchanger within the cooler 100 drips out of the air inlet 104.

[0025] Reference FIG. 2A to FIG. 2B , shows a perspective view of a galley cart compartment 200 including an embodiment of the inventive concepts disclosed herein. The galley cart compartment 200 suitable for a cooling cart includes a cooling air outlet duct 202 having an outlet connection point 204 suitable for connection to an air outlet of a cooler and defining one or more air supply outlets 206. The galley cart compartment 200 also includes an inlet duct 208 having an inlet duct 208 having an inlet connection point 210 suitable for connection to an air inlet of a cooler.

[0026] The intake duct 208 defines one or more biasable cooling air return ports 212 disposed below the inlet connection point 210. In at least one embodiment, the intake duct 208 further defines one or more open cooling air return ports 214 disposed distally of the inlet connection point 210.

[0027] Reference FIG. 3A to FIG. 3B, shows a perspective view of a cooler 300 and an air intake duct 302 including an embodiment of the inventive concepts disclosed herein. When the cooler 300 is operated in a defrost cycle, condensate from the cooler 300 is discharged via an air inlet in the bottom of the cooler 300 to drip into the air intake duct 302 and is handled by a condensate hose 304, which drains the condensate into a waste water system. The air intake duct 302 requires one or more air return ports 306, 308 to draw outside air into the cooler 300 during the cooling cycle and allow air to escape when operating in a defrost cycle.

[0028] The air return ports 306, 308 include at least one biasable air return port 306 and may include one or more open air return ports 308. The biasable air return ports 306 include the return air duct grilles described herein, which are disposed below the cooler 300 and in line with the path of condensate dripping from the cooler 300 during a defrost cycle. The open air return ports 308 may be completely open or may include a mesh configured to allow air to pass through but prevent insect intrusion; or they may include a filtration system to prevent dust intrusion.

[0029] In at least one embodiment, during a cooling cycle or a defrost cycle, air flow may be balanced between the air return ports 306 , 308 via a baffle 310 disposed within the intake duct below the cooler 300 .

[0030] In at least one embodiment, the intake duct 302 includes an angled surface 312 configured to act as a condensate collector by generally angling the condensate hose 304 .

[0031] In at least one embodiment, the biasable air return port may also include a mesh to prevent insect intrusion when in the open orientation.

[0032] Reference Figure 4 , shows a perspective view of a return air duct grille 400 according to an exemplary embodiment of the inventive concepts disclosed herein. The return air duct grille 400 includes hinged slats 402 configured to pivot about respective pivot points 404. When installed in an intake duct, the return air duct grille 400 is arranged and oriented so that when the cooler is operating in a cooling cycle, the hinged slats 402 pivot to an open orientation, thereby drawing air into the air inlet and reducing the air pressure within the intake duct. In at least one embodiment, the hinged slats 402 pivot only based on air flow due to air pressure differentials. In at least one embodiment, the hinged slats 402 are actively biased in the open orientation.

[0033] In at least one embodiment, when in the closed orientation, the hinged slats 402 form a generally continuous surface to allow condensate to flow over the closed hinged slats 402 toward the condensate hose. In at least one embodiment, the return duct grille 400 is arranged at an angle within the corresponding inlet duct to allow condensate to move toward the condensate hose via gravity; for example, the return duct grille 400 can be disposed in an inclined surface of the inlet duct. In addition, the generally continuous surface is configured to protrude sufficiently from the inner surface of the inlet duct to prevent discharged condensate from accumulating near the return duct grille 400.

[0034] In at least one embodiment, during a defrost cycle, the hinged slats 402 are maintained in a closed orientation via gravity, airflow, and air pressure differentials created by the cooler's air inlet. In at least one embodiment, the hinged slats 402 are actively biased to the closed position.

[0035] In at least one embodiment, each hinged slat 402 covers the next lower hinged slat 402 to form a fluid seal. A gasket 406 is disposed near the top of the return air duct grill 400 to form a fluid seal on top of the topmost hinged slat 402.

[0036] Although the embodiments illustrated herein generally show the return air duct grille 400 installed with horizontally running hinged slats 402, it is contemplated that the return air duct grille 400 may be installed with generally vertically arranged hinged slats 402 if installed in a surface other than an inclined surface directly below a cooler.

[0037] Reference Figure 5 , shows a partial perspective view of a return air duct grille 500 according to an exemplary embodiment of the inventive concepts disclosed herein. The return air duct grille 500 includes a plurality of hinged slats 502, each of which is configured to pivot about a corresponding pivot point 504. In at least one embodiment, each hinged slat 502 includes a slat weight 506 to bias the hinged slat 502 into a closed orientation. The slat weight 506 can be defined by the average air pressure difference between the inside and outside of the intake duct during a defrost cycle.

[0038] In at least one embodiment, the pivot range of the hinged slat 502 is limited by at least one angle limiter 508. The angle limiter 508 prevents the hinged slat 502 from opening beyond a predetermined point because the hinged slat 502 may exceed a threshold where the hinged slat 502 can no longer close during normal operation.

[0039] It is believed that through the foregoing description of the embodiments of the disclosed inventive concept, the inventive concept disclosed herein and its many attendant advantages will be understood, and it is obvious that various changes can be made to the form, construction, and arrangement of the components without departing from the broad scope of the inventive concept disclosed herein or sacrificing all its material advantages; the various features from various embodiments can be combined to obtain other embodiments. The forms described above are only illustrative embodiments thereof, and the following claims are intended to encompass and include such changes. In addition, any features disclosed in connection with any single embodiment may be combined in any other embodiment.

Claims

1. A return air duct grille, comprising: a plurality of partially overlapping hinged strips configured to form a fluid seal when in a closed orientation; at least one slat weight disposed on each of the hinged slats and configured to bias the corresponding hinged slat into a closed orientation, each slat weight being defined by an average air pressure differential between an interior and exterior of the return air duct during a defrost cycle; and At least one angle limiter is configured to limit the maximum deflection of at least one hinged slat when in an open orientation to prevent the at least one hinged slat from opening beyond a predetermined point in the open orientation, wherein the predetermined point includes an angle beyond which the at least one hinged slat will not be able to automatically close during normal operation.

2. The return air duct grille according to claim 1, further comprising an insect net.

3. The return air duct grille of claim 1, further comprising a gasket disposed adjacent a hinged edge of an uppermost hinged slat.

4. The return air duct grill of claim 1, further comprising a biasing spring configured to bias the hinged slats into a closed orientation.

5. A return air duct, comprising: an inclined surface configured to be inclined toward the condensate hose; and at least two grilles, each grille comprising a plurality of partially overlapping hinged slats configured to form a fluid seal when in a closed orientation disposed along the inclined surface; at least one slat weight disposed on each of the hinged slats and configured to bias the corresponding hinged slat into a closed orientation, each slat weight being defined by an average air pressure differential between an interior and exterior of the return air duct during a defrost cycle; at least one open cooling air return port disposed in the inclined surface and distal from an inlet connection point defined by the return air duct; and a baffle disposed between at least one grille and the cooling air return port, in: The hinged slats are biased into a closed orientation when the air pressure differential between the interior of the return air duct and the exterior of the return air duct is below a threshold; The hinged slats are configured to an open orientation when the air pressure difference between the interior of the return air duct and the exterior of the return air duct is above the threshold; The baffle is configured to balance air flow through the at least two grilles; and The hinged slats of the at least two grilles form a continuous surface in the closed orientation and protrude into the interior space of the return air duct to prevent condensate from accumulating adjacent the at least two grilles.

6. The air return duct according to claim 5, wherein: At least one grille further includes at least one angle limiter configured to limit a maximum deflection of at least one hinged slat when in an open orientation.

7. The return air duct according to claim 5, further comprising an insect net.

8. The air return duct according to claim 5, wherein: At least one of the grilles further comprises a washer disposed adjacent a hinged edge of the uppermost hinged slat.

9. An aircraft galley, comprising: a cooling air outlet duct defining an outlet connection point; a return air duct defining an inlet connection point and comprising: an inclined surface configured to be inclined toward the condensate hose; at least one grille comprising a plurality of partially overlapping hinged slats configured to form a fluid seal when in a closed orientation disposed along the inclined surface; and at least one slat weight disposed on each of the hinged slats and configured to bias the corresponding hinged slat into a closed orientation, each slat weight being defined by an average air pressure differential between an interior and exterior of the return air duct during a defrost cycle; a cooler disposed between the outlet connection point and the inlet connection point; and The condensate hose, which is connected to the return air duct and the aircraft waste water system, in: The hinged slats are biased into a closed orientation when the air pressure differential between the interior of the return air duct and the exterior of the return air duct is below a threshold; and The hinged slats are configured to an open orientation when the air pressure difference between the interior of the return air duct and the exterior of the return air duct is above the threshold.

10. The aircraft galley according to claim 9, wherein: The at least one grille further includes at least one angle limiter configured to limit a maximum deflection of the at least one hinged slat when in an open orientation.

11. The aircraft galley according to claim 9, further comprising an insect net.

12. The aircraft galley according to claim 9, further comprising at least one open air inlet port, the air inlet port being arranged in the inclined surface and distal from an inlet connection port defined by the aircraft galley. 13 . The aircraft galley according to claim 12 , further comprising a baffle arranged between the at least one grille and the air inlet port.

14. The aircraft galley according to claim 9, wherein: The at least one grille further comprises a washer arranged adjacent a hinged edge of the uppermost hinged slat.

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