Abstract:
The present invention is a light weight, easily fitted, and removable protective panel for an aircraft galley monument that incorporates a thermal barrier for heat loss control. The thermal barrier encloses a high percentage of the cold bridges between the chilled compartments of a galley cooler and the ambient surroundings, allowing an aircraft galley cooler to efficiently and economically meet its target temperature. The protective panel is multi-configurable and capable of being customized to the requirements of a particular aircraft.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Application No. 61/614,755, filed Mar. 23, 2012, incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Large commercial aircraft that service hundreds of passengers at a time is typically equipped with a service station, or galley, that is used to house all of the equipment and foods for the passengers&#39; and crew&#39;s meal and beverage service. The galley is typically a built in structure that is part of the aircraft, designed to meet the needs of the particular aircraft while adhering to the goals and limitations of weight conservation and space efficiency that is critical to all aircraft. Each galley will typically have ovens to heat food, beverage makers to make coffee and espresso, waste disposal areas, and chillers or coolers to store the meals and perishables until they are ready to be served. These chillers or coolers and typically built into the galley, and must be able to store milk, fruits, frozen meals, and other types of perishables at a temperature that allows the food to be safely served after several hours in flight. 
         [0003]    In order to meet the health and safety requirements to preserve perishable foods for consumption by passengers during an airlines in-flight catering service, a storage structure such as a galley has to have a level of thermal insulation that is capable of resisting conductive losses to a level that will allow the galley to meet or exceed the manufacturer&#39;s and airworthiness authority&#39;s requirements for the safe storage of food stuffs over a specific period, using the galley chilling system provided for that galley. The minimum thermal resistance level of a food storage structure is usually specified as an average value for the entire monument, which takes into account losses through cold bridges between the chilled compartments and the warmer exterior ambient temperatures. 
         [0004]    These cold bridges typically take the form of metallic items such as floor fittings, edge members, potted inserts, bobbins, embedded and mouse hole blocks, sliding tables, door hinges, latches, and access panels, as well as poorly insulated nonmetallic areas such as recessed panels, cut outs and cable passes. Each of these types couplings and structures conduct heat into the galley, which must be removed by the refrigeration unit. The amount of heat that is allowed across these structures is dependent upon a property called the thermal resistance. The average thermal resistance performance of a chilled storage structure such as a chiller or cooler equates to the capability of the nonmetallic panel that forms the housing, less any losses through cold bridges and poorly insulated areas. 
         [0005]    Galley panels made from a 13 mm (½″) Nomex® cored pre-impregnated structural panel is insufficient to maintain aircraft galley chilled compartments at or below the required safe temperature for perishable food stuffs. Therefore, in order to improve the monument&#39;s thermal capability to allow perishables to be stored safely, either the thickness of the panel has to be increased or supplemental insulation has to be added to the structure. 
         [0006]    In addition to the thermal losses, the reduction of intrusive noise into an aircraft cabin, usually produced by the routine operation of an in-flight airline catering service, is a prime objective of the aircraft manufacturers. Much of this noise can be generated by galley insert equipment (“GAINS”), such as ovens, refrigerators, beverage makers, and the like, along with the incumbent noise introduced by the cabin crew preparing meals. That is, the preparing of meals includes removing standard meal boxes from their compartments, filling meal carriers for ovens, opening and closing compartment doors, moving carts from their compartments, and so on. Aircraft manufacturers seek to reduce the overall noise in the passenger cabin by providing various sound attenuation mechanisms such as using sound absorbing materials. By incorporated such materials into the galley surfaces, the acoustic levels inside the cabin due to the preparation and clean-up of the beverage and meal service can be significantly reduced. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is a light weight, easily fitted, and removable protective panel for an aircraft galley monument that incorporates a thermal barrier for heat loss control. The thermal barrier encloses a high percentage of the cold bridges between the chilled compartments of a galley cooler and the ambient surroundings, allowing an aircraft galley cooler to efficiently and economically meet its target temperature. The protective panel is multi-configurable and capable of being customized to the requirements of a particular aircraft. In addition, the thermal barrier provides insulation where it is needed most, while saving weight by eliminating areas that are not as critical. The panels are versatile enough to be used with non-chilled monuments as well, without the insulation. Due to the panel&#39;s structure and materials, exceptionally high insulation values are possible with a minimum thickness, resulting in a very small increase to the overall galley foot print. In a preferred embodiment, the galley can include an acoustic suppressing layer as well to yield a super silent galley as well as a thermally efficient galley. This concept can be extended to use the center line galley panels as cabin sound absorbers, reducing the overall aircraft cabin noise levels. It has been shown that the shell surface remains easily cleanable even if used for cabin sound absorption. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of the exterior of a galley incorporating the present invention; 
           [0009]      FIG. 2  is a front view of a preferred embodiment of a beverage station; 
           [0010]      FIG. 3  is a front view of a first embodiment of a food preparation station; 
           [0011]      FIG. 4  is a cross-sectional view of a portion of the outer thermal shell of the galley of 
           [0012]      FIGS. 1-3 ; and 
           [0013]      FIG. 5  is a cross-sectional view of a portion of the outer thermal shell of the galley of  FIGS. 1-3  with acoustic suppressant. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]      FIG. 1  illustrates an exterior view of a modular integrated galley comprising a stand-alone beverage station  100  and a stand-alone food preparation station  200 . The beverage station  100  provides coffee, espresso, and a variety of beverages that can be served to passengers, while the food preparation station  200  includes ovens, refrigerators, and equipment necessary for the storage, preparation, and clean-up of meal service. On the exterior of each station  100 ,  200  is a display screen  110 , 210 , such as for example an LED screen, that can be used to provide instructions to passengers, display advertisements that can generate revenue for the airlines, or provide information on the amenities provided by the galley. The exterior of each station is also preferably equipped with a branding placeholder  215  that can be used to promote the airlines or provide advertising space that can be leased by the airlines. The branding placeholder  215  is large and in full view of the passengers for maximum exposure and visibility. Both the beverage station  100  and the food preparation station  200  are formed with an outer shell  300  that serves to thermally insulate, and optimally acoustically attenuate, the galley from the environment. 
         [0015]      FIG. 2  illustrates an exemplary stand-alone beverage station  100  of the galley, comprising a light weight structure  13  encased in a thermal shell  300 . The beverage station  100  is adapted to serve as a beverage distribution center in a commercial aircraft. The modular beverage center  100  features several integrated equipment for servicing passengers, including a side refrigeration unit for self-serving of soft drinks to passengers, two half ovens  12 , two coffee makers  14 , two espresso makers  16 , and two hot water dispensers  18 . The structure  13  includes six beverage cart storage compartments  20  that house beverage carts used to facilitate service to passengers, a sink  30  and faucet  29 , a top loading trash chute, task lighting, and a touch screen user interface. All of the elements are arranged in a cost and space efficient manner that allows functionality without sacrificing performance. 
         [0016]      FIG. 3  illustrates a food preparation station  200  that operates in conjunction with the beverage station  100  to achieve a full-service galley. The food preparation station  200  includes a side refrigeration unit that serves as a passenger self-service cooler, a double refrigerator  50 , a double oven  60 , a half oven  65 , six beverage cart storage compartments  20 , and an extendable work deck. As with the beverage station, the food preparation station is encased in a thermal shell  300  that insulates the contents of the galley and keeps perishables stored therein at the proper temperature. 
         [0017]      FIG. 4  illustrates an outer shell  300  enclosing the exterior surface of the aircraft monuments  100 ,  200  of  FIGS. 1-3 . The shell  300  includes the back, and both side walls (e.g. center line galley), which allows the shell  300  to be easily attached and/or removed when the aircraft is in service. The shell  300  includes an outer layer  310  serving as an impact resistant skin having a depth of approximately 1.5 millimeters. The skin  310  is formed of a hard material such as a carbon reinforced composite pre-impregnated, fiberglass, Kevlar, or other thermoplastic, and is designed to be fitted in sections to the monument. The skin  310  performs two functions: a protective layer for the vacuum insulated panels (“VIP”) and as a carrier for an airline&#39;s choice of decor or trim. The skin  310  may be bonded in a conventional manner using a high temperature contact adhesive. Below the skin  310  is a layer of carbon fiber composite material  320  that is bonded to the monument. The carbon fiber composite material can have a thickness of approximately ten millimeters (10 mm). 
         [0018]    Sandwiched between the impact resistant outer skin  310  of the shell  300  and the carbon fiber composite panel  320  is a layer of thermal insulation  330 , such as Nanopore™ available from Nanopore Inc. of Albuquerque, N.M. The thermal insulation  330  may be in the form of 3 mm thick vacuum insulation panel (VIP) tiles, which may alternatively be attached to either the monument structure  13  or to the inner wall of the outer skin  310 . One benefit of using the tiles described above is that the thermal insulation tiles can be selectively located and positioned where an improvement to the thermal insulation properties of the galley are required. For non-chilled areas that do not need thermal insulation, the shell  300  may substitute a light weight filling panel or core, or spacers to maintain the correct distance from the structural outer surface. In this manner, both cost and weight are minimized while maximizing thermal efficiency. 
         [0019]    To bind the skin  310  of the shell  300  to the carbon fiber composite panel  320 , a series of anchor pins  340  are inserted through the skin and into the panel, compressing the multi-layers into a rigid panel. An aesthetic anchor pin cover  350  can be used over the pin  340  to present a cleaner, sleeker appearance to the galley. 
         [0020]      FIG. 5  illustrates a second embodiment of a shell  360  that includes the structure of  FIG. 4 , but also includes an additional layer consisting of 20-25 mm of and acoustic foam  370 , such as an open cell acoustic foam. The foam  370 , together with a 3 mm layer of VIP thermal insulation  330 , serves the dual purposes of thermal insulation along with the absorption of the reverberant sound generated at the working face of the galley. The foam  370  may alternatively be attached either to the outer surface of the VIP panels  330 , or to the inside surface of the outer skin  310 . Thermally, the galley will achieve an even better resistance to heat loss due to the inherent thermal insulation properties of the foam  370 , and the foam and thermal panel combination enhances the monument&#39;s external impact resistance as well as its impact sound absorbent qualities. 
         [0021]    The removable outer skin  310  serves as a protective barrier that provides damage protection to the otherwise susceptible thermal layer  330 , and acts as a carrier for external decor trim. The VIP thermal barrier  330  further serves to enclose all potential cold bridges from chilled compartments on all but the working face of the monument (e.g., center line galley). Lateral refrigerated galleys can be insulated on the reverse surface using VIP panels without the need for a protective skin  310 . An advantage of the present system is that damaged skin  310  and/or VIP panels  330  can be replaced in service without disturbing the monument&#39;s aircraft attachment points. 
         [0022]    Selective placement of the thermal panels  330  (and the sound absorbing foam  370 ) allow enhanced insulation at the locations where it is identified as being important or effective, leaving other areas untreated to save weight. The invention adds only a minimal increase ×1 of 4.5 millimeters in the example of  FIGS. 4 , and  24 . 5  millimeters in the example of  FIG. 5  to the galley&#39;s foot print while providing superior thermal loss resistance and acoustic attenuation. 
         [0023]    By using an open weave pre-impregnated carbon reinforced panel  380  for the skin  310 , and micro perforating the decor laminate, the outer shell  360  absorbs most exterior noise, reducing the overall sound levels in the passenger cabin. The present invention is adaptable to all types of narrow or wide bodied commercial aircraft monuments both for new and existing airplane types or variants.