Abstract:
A galley cart system employs a dry ice compartment and a refrigeration compartment in a galley cart in flow communication with the dry ice compartment. A ventilation system is in interruptible flow communication with at least the refrigeration compartment and is for receiving gas discharged from at least the refrigeration compartment.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is copending with application Ser. No. 14/202,366 filed on Mar. 10, 2014 entitled Dry Ice Draw Through Galley Cooling and application Ser. No. 14/202,495 filed on Mar. 10, 2014 entitled CO2 Shut Off Method for Dry Ice Sublimation Inside a Galley Cart both having a common assignee with the present invention, the disclosures of which are incorporated herein by reference. 
     BACKGROUND INFORMATION 
     Field 
     Embodiments of the disclosure relate generally to galley cart systems for transportation vehicles and more particularly to a collapsible bulb seal with one or more orifices for collection of CO2 when expanding from a collapsed to expanded position and expulsion of CO2 when collapsing from the expanded position. 
     Background 
     Galley carts employed for food service in transportation vehicles such as aircraft and trains often require cooling to maintain food and beverages at a temperature that is cooler than a cabin of the vehicle, At least some known carts include or connect to a refrigeration system (a chiller) that provides cool air to an interior volume of the cart to cool the food/beverages. However, the chiller is powered by the vehicle systems, reducing the amount of power available to the vehicle for propulsion, thrust, etc, As such, the chiller is an inefficient draw on the power supply system of the vehicle. Further, such a chiller system adds weight and complexity to the vehicle, Accordingly, some galley carts are configured to contain dry ice that cools the food/beverages as it sublimates. One drawback with the use of dry ice is the carbon dioxide gas (CO2) sublimate that is released. At least in aircraft, the Federal Aviation Administration has set forth requirements for the maximum CO2 concentration in a cabin of the aircraft, The sublimation of the dry ice may cause the CO2 concentration in the cabin to exceed the maximum parts-per-million (ppm), For example, the CO2 gas may escape from the cart into the cabin when the door of the cart is opened in the galley area or in the aisle as food/beverages are served (a transient condition), Further, the CO2 gas may escape from the cart through provided leak paths to ensure that the pressure within the cart does not exceed a maximum threshold as the dry ice sublimates (a steady-state condition). Dry ice, providing CO2 sublimation as a coolant, is a commonly available, cost effective and volumetrically efficient refrigerant for such use. However, limiting venting of CO2 gas from the galley carts to avoid undesirable buildup of CO2 in passenger compartments is preferred. 
     It is therefore desirable to provide structurally simple and cost effective structure for control of CO 2  sublimation in galley carts. 
     SUMMARY 
     Exemplary embodiments provide a galley cart having a housing defining a cavity. A door is coupled to the housing, the door configured to be moved between a closed position and an open position. A seal assembly is coupled between the housing and the door with at least one bulb seal configured to draw gas in when the door is in the open position and to exhaust the gas when the door is in the closed position. 
     The embodiments provide a method for collection of CO 2  sublimate in a galley cart by compressing a bulb seal having at least one aperture between the galley cart door and housing. Upon opening the door, the bulb seal expands drawing in CO 2  sublimate into the bulb seal through the aperture. Upon closing the door, the bulb seal is compressed exhausting CO 2 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings. 
         FIG. 1A  is a perspective view of an example a galley cart in which the described embodiments may be employed; 
         FIG. 1B  is a second perspective view of the galley cart of  FIG. 1A  with a first door in a partially open position; 
         FIG. 2A  is a partial bottom section view of the galley cart showing the door in a closed position with a compressed bulb seal; 
         FIG. 2B  is a detailed partial bottom section view of the galley cart showing the door in a closed position with a compressed bulb seal; 
         FIG. 3A  is a detailed partial bottom section view of the galley cart showing the door in a partially open position for a first embodiment with the bulb seal attached to the door and with the compressed bulb seal expanded; 
         FIG. 3B  is a detailed partial bottom section view of the galley cart showing the door in a partially open position for a second embodiment with the bulb seal attached to the door seal relief and with the compressed bulb seal expanded; 
         FIG. 4  is a perspective view of an example bulb seal; 
         FIG. 5A  is a partial bottom perspective view of the bulb seal showing the compressed seal and orifice; 
         FIG. 5B  is a section view of the bulb seal of  FIG. 5A  demonstrating the interior volume of the compressed seal; 
         FIG. 6A  is a partial bottom perspective view of the bulb seal showing the partially compressed seal and orifice; 
         FIG. 6B  is a section view of the bulb seal of  FIG. 6A  demonstrating the interior volume of the partially compressed seal; 
         FIG. 7A  is a partial bottom perspective view of the bulb seal showing the fully expanded seal and orifice; 
         FIG. 7B  is a section view of the bulb seal of  FIG. 7A  demonstrating the interior volume of the fully expanded seal; 
         FIG. 8  is an interior perspective view of the door with a bottom bulb seal; 
         FIG. 9  is an interior perspective view of the door with a peripheral bulb seal; 
         FIG. 10  is a cross section of a bulb seal with a first exemplary attachment tab; 
         FIG. 11  is a cross section of a bulb seal with a second exemplary attachment tab; 
         FIG. 12  a cross section of a bulb seal with an alternative shape and attachment tab; and, 
         FIG. 13  is a flow chart of a CO 2  capture method enabled by the disclosed embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments described herein provide a galley cart for use in a transportation vehicle that includes a seal assembly having a hollow bulb seal positioned between the cart housing and the door of the cart. The bulb seal is coupled to the housing or the door at any suitable location. In one embodiment, the bulb seal is positioned vertically along an edge of the door opposite of the door hinges. The bulb seal defines a hollow cavity, and two end caps coupled to the seal further enclose the cavity. At least one of the end caps includes at least one aperture; however, the end cap(s) can include any suitable number and/or arrangement of apertures. 
     When the cart door opens, the bulb seal expands and draws gas through the aperture into the seal cavity. As such, when the cart door opens, the expanding bulb seal may help prevent escape of CO2 gas into the cabin by drawing the CO2 gas, and possibly other gas, into the cavity (the CO2 gas will be near the bottom of the cart because of its relative weight). When the cart door closes, the bulb seal is compressed and exhausts the gas from the seal cavity. In the example embodiment, the bottom end cap includes the aperture(s) such that gas is exhausted out of the bottom of the cart because the gas (CO2) is heavier than the air in the cabin and the gas will be lower than a breathing height of the passengers. In alternative embodiments, the orifice in the bulb seal may be positioned to exhaust the gas back into the galley cart interior. Accordingly, the embodiments described herein may reduce CO2 in the cabin during transient conditions and may exhaust CO2 gas in a manner to avoid inhalation by the passengers. The terms “(CO2 gas”, “CO2 sublimate”, and “sublimate” are used interchangeably herein. 
     Referring to the drawings,  FIG. 1A  is an isometric view of a galley cart  100  which may be employed in the embodiments disclosed herein. In one aspect of this embodiment, the galley cart  100  includes a housing  102 . In the illustrated embodiment, the housing  102  has a first side  104 , a second side  106 , a top  108 , and a bottom  110 . The galley cart  100  further includes a first door  112  positioned on one end of the housing  102 , and, for certain embodiments, a second door (not shown) is positioned on an opposite end of the case  102 . Each of the doors  112  can further include one or more hinges  114  and a latch  116 . The hinges  114  pivotally attach the doors  112  to the housing  102 . The latch  116  can be configured to releasably engage corresponding receivers  118  attached to the housing  102  when the doors  112  are in closed positions as illustrated in  FIG. 1A . 
     By disengaging the latch  116  from the corresponding receiver  118 , the doors  112  can be opened outwardly providing access to an interior cavity  120  of the housing  102  as shown in  FIG. 1B . Positioning the doors  112  at respective ends of the housing  102  allows flight attendants to conveniently access food stored within the housing  102  from either end of the galley cart  100 . In other embodiments, the second door can be omitted if desired. Additionally, the doors  112  are received in a recess  122  in the housing  102  to be described in greater detail subsequently. Wheels or casters  124  allow the galley cart to be easily maneuvered within the service areas and aisles of the aircraft. 
     Dry ice may be stored in the galley cart to provide CO 2  sublimate in the interior cavity as a coolant for food or beverages stored in the cart. The CO 2  sublimate will tend to pool near the bottom of the interior cavity  120  in the cart. A hollow bulb seal  126  is mounted in the recess  122  into which the doors  112  are received as shown in  FIGS. 2A, 2B and 3A or 3B . In the embodiment shown, the bulb seal  126  is mounted in the recess  122  opposite the hinge attachment. With the door  112  in a closed position, the bulb seal is compressed as shown in  FIGS. 2A and 2B . With the door open as shown in  FIGS. 3A or 3B , the bulb seal is expanded. The bulb seal  126  may be attached to the recess  122  as in  FIG. 3A  or to the door  112  as in  FIG. 3B . An aperture  128  placed in a bottom cap  130  of the bulb seal  126 , shown in detail in  FIG. 4 , provides a port into which gas, such as CO 2  gas, in the cart is drawn during opening of the door  112 . 
     Opening of the door  112  results in the bulb seal  126  transitioning from a compressed condition to an expanded condition thereby increasing interior volume and creating a reduced pressure within the bulb seal. This transition is shown in  FIGS. 5A, 5B, 6A, 613, 7A and 7C . In  FIG. 5A  the bulb seal  126  is in a compressed condition with a resulting cross sectional area  130  as shown in  FIG. 5B . As the door  112  is opened, the bulb seal begins to expand as shown in FIG. 6 A, resulting in an increased cross sectional area  132  as shown in  FIG. 613 . The increased cross sectional area results in a greater volume within the bulb. When fully expanded as shown in  FIGS. 7A and 7B , the maximum cross sectional area  134  results. The perimeter of the seal remains the same but internal volume (and vacuum) increases when removing compression in the system. 
     Upon closing the door  112 , the bulb seal  126  is recompressed expelling the accumulated CO2 gas. A relief channel  136  (seen in  FIG. 1B ) may be provided to vent the CO2 gas from the compressing of bulb seal downward from the bottom  110  of the cart. This release of CO2 gas at essentially floor level may preclude undesirable distribution of CO2 to be breathed by passengers in the vehicle. 
     As shown in  FIG. 4 , additional apertures  138  may be provided along the length of the bulb seal to draw CO 2  gas into the expanding seal from a greater portion of the interior cavity of the cart. 
     In an alternative embodiment, the bulb seal  126  may be placed along the bottom edge of the door  112  and cart housing  102  as shown in  FIG. 8  with apertures  138  as shown in  FIG. 4  oriented along the bottom of the door. In another alternative embodiment, the bulb seal  126  may extend around the door  112  as a complete peripheral seal around the door  112  as shown in  FIG. 9 . Multiple apertures  138  may be directed downward for collecting CO 2  gas from the lower portion of the internal cavity as the door  112  is opened expanding the seal and exhausting the CO 2  gas downward as the door is closed compressing the seal. Additional apertures along the periphery for collecting CO 2  gas from within the internal cavity may also be provided. 
     In other alternative embodiments, the bulb seal may be positioned with the apertures in communication with the interior cavity  120  to exhaust the collected CO 2  gas back into the interior volume upon closing of the door  112 . 
     As shown in  FIG. 4  and  FIG. 10 , the seal assembly may incorporate a T-rib  140  for attachment of the bulb seal  126  to the galley cart door or recess. As seen in  FIGS. 3A and 3B , the T-rib  140  is received within a T-slot  142  in either the recess  122  or door  112  to constrain the bulb seal  126 . An alternative attachment of the bulb seal may be accomplished with a flat flange  144  as shown in  FIG. 11 . Alternative cross sectional shapes may also be employed for the bulb seal such as a rectangular seal  146  as shown in  FIG. 12 . 
     As shown in  FIG. 13 , the embodiments herein provide for capture of CO 2  gas during opening of a galley cart door and directed exhausting of the collected CO 2  gas upon closing the galley cart door. A bulb seal is compressed between the galley cart door and housing, step  1302 . The door is opened, step  1304 , expanding the bulb seal and drawing in CO 2  gas through one or more apertures, step  1306 . Upon closing the door, step  1308 , the bulb seal is compressed exhausting CO 2  gas, step  1310 . In certain embodiments, the exhausted CO 2  gas is directed downward out of the galley cart, step  1312 . In alternative embodiments, the CO 2  gas is exhausted into the internal cavity of the cart, step  1314 . 
     Having now described various embodiments of the invention in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present invention as defined in the following claims.