Controlling flow of dry ice sublimation inside a galley cart

1. A galley cart comprising:

a housing;

a door coupled to the housing, the door configured to be moved between a closed position and an open position;

a vent plate in the housing to communicate between a first compartment and a second compartment; and

a valve plate immediately adjacent the vent plate, said vent plate and valve plate integrated into a bottom of the first compartment, said valve plate movable relative to the vent plate from an aligned venting position when the door is in the closed position to a blocking position displaced from alignment to seal the first compartment from the second compartment when the door is in the open position.

2. The galley cart as defined in claim 1 wherein the first compartment is a storage compartment for dry ice.

3. The galley cart as defined in claim 2 wherein the second compartment is a refrigeration compartment.

4. The galley cart as defined in claim 2 further comprising a vent valve in the storage compartment.

5. The galley cart as defined in claim 1 wherein the vent plate incorporates an array of apertures and the valve plate incorporates a mating array of apertures, said valve plate aligning the mating array of apertures with the array of apertures in the vent plate in the venting position and misaligning the mating array of apertures from the array of apertures in the vent plate in the blocking position.

6. The galley cart as defined in claim 5 wherein the first compartment is a storage compartment for dry ice and the second compartment is a refrigeration compartment, and wherein aligning of the mating array of apertures with the array of apertures in the vent plate in the venting position configures the vent plate for flow of sublimating CO2 gas from storage compartment to the refrigeration compartment.

7. A galley cart comprising:

a housing;

a door coupled to the housing, the door configured to be moved between a closed position and an open position;

a vent plate in the housing to communicate between a first compartment and a second compartment;

a valve plate adjacent the vent plate, said valve plate movable from a venting position when the door is in the closed position to a blocking position when the door is in the open position; and,

at least one resilient element urging the valve plate into the blocking position when the door is moved to the open position.

8. A method for controlling a flow of CO2 sublimate in a galley cart, said method comprising:

sublimating CO2 gas from dry ice in a dry ice storage compartment to flow through an array of apertures a vent plate in a housing having a door coupled to the housing, the door configured to be moved between a closed position and an open position;

and

aligning a mating array of apertures in a valve plate with a mating array of apertures with the vent plate in a first venting position to allow the flow of the CO2 gas into a refrigeration compartment, said valve plate movable relative to the vent plate from an aligned venting position when the door is in the closed position to a blocking position displaced from alignment to seal the first compartment from the second compartment when the door is in the open position.

9. The method as defined in claim 8 further comprising:

opening a the door of the cart; and

urging the valve plate laterally with respect to the vent plate to the blocking position mis-aligning the mating array of apertures in the valve plate and the array of apertures in the vent plate thereby preventing flow of the CO2 gas through the apertures in the vent plate.

10. The method as defined in claim 9 further comprising:

closing the door; and returning the valve plate in lateral motion into alignment of the mating array of apertures and array of apertures in the vent plate in the aligned venting position thereby resuming flow of the CO2 gas through the array of apertures in the vent plate.

11. The method as defined in claim 10 wherein the step of urging the valve plate comprises expanding a resilient element to urge the valve plate laterally.

12. The method as defined in claim 11 wherein the step of returning the valve plate comprising compressing the resilient element.

13. The method as defined in claim 10 further comprising relieving excess CO2 gas pressure in the storage compartment with the valve plate in the blocking position by venting through a relief valve.