Galley Cart Dry Ice Venting for Cabin CO2 Control

Solution Overview

Problem

Galley carts in transportation vehicles face inefficiencies with traditional refrigeration systems, including excessive power consumption and weight, and the use of dry ice leads to CO2 sublimation that can exceed safe cabin concentrations, requiring effective metering and venting solutions to maintain cooling and prevent CO2 buildup.

Innovation Solution

A galley cart system with a dry ice compartment and refrigeration compartment in flow communication, featuring a ventilation system that interrupts flow to receive and meter CO2 sublimation, utilizing valves and ducting for controlled distribution and venting, including connections to existing lavatory and wastewater systems for efficient external venting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a chiller is used to cool food and beverages in the galley cart, then cooling is provided, but power consumption increases and weight is added

Engineering Contradiction:

Improvecooling capabilityVSAvoidpower consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent extracts the harmful CO2 sublimation from the cart interior by providing a dedicated vent path that directs CO2 gas from the dry ice compartment through a valve and outlet away from the cart. This separates the cooling function (dry ice sublimation) from the harmful effect (CO2 buildup), allowing dry ice to be used without exceeding cabin CO2 concentration limits.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a valve as an intermediary component between the dry ice compartment and the cart interior. The valve controls and meters the sublimation process, regulating CO2 gas flow to maintain safe concentrations while providing adequate cooling. This intermediary enables precise control of the sublimation rate to balance cooling needs with safety requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If dry ice is used to cool food and beverages, then power consumption is reduced, but CO2 concentration in the cabin may exceed maximum limits

Engineering Contradiction:

Improvepower consumptionVSAvoidCO2 concentration

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful CO2 sublimation from the cart interior by providing a dedicated vent path that directs CO2 gas from the dry ice compartment through a valve and outlet away from the cart. This separates the cooling function (dry ice sublimation) from the harmful effect (CO2 buildup), allowing dry ice to be used without exceeding cabin CO2 concentration limits.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements a feedback mechanism where the valve responds to pressure differential between the dry ice compartment and ambient environment. As CO2 sublimates and pressure increases, the valve opens to release gas; as pressure equalizes, the valve closes. This automatic feedback control maintains CO2 concentration within safe limits while maximizing cooling efficiency.

Inventive Principle:

Principle #23Feedback

3Temperature

If the dry ice compartment pressure exceeds maximum threshold, then cooling continues, but CO2 escapes through leak paths

Engineering Contradiction:

Improvecooling functionVSAvoiduncontrolled CO2 escape

Core Design Contradiction:

TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the valve responds to pressure differential between the dry ice compartment and ambient environment. As CO2 sublimates and pressure increases, the valve opens to release gas; as pressure equalizes, the valve closes. This automatic feedback control maintains CO2 concentration within safe limits while maximizing cooling efficiency.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The valve system is designed to operate autonomously based on pressure differential, requiring no external control or power source. The system self-regulates CO2 release by opening when pressure exceeds thresholds and closing when pressure equalizes, providing self-service pressure management that prevents uncontrolled escape while maintaining cooling.

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system provides uniform cooling, prevents CO2 buildup, and reduces pressure issues by effectively metering and venting CO2 sublimation, enhancing the efficiency of galley cart operations while adhering to safety standards.

Implementation Method 1

the use of dry ice leads to the carbon dioxide gas (CO2) sublimate that is released

Methodology Applied

Scientific EffectSublimation: Sublimation

Implementation Method 2

A ventilation system is in interruptible flow communication with at least the refrigeration compartment and is configured to receive gas discharged from at least the refrigeration compartment

Methodology Applied

Scientific EffectGas flow:

Data Source

PatentUS11440662B2Dry ice draw through galley cooling

Publication Date: 2022.09.13 THE BOEING CO

AI summary

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 configured to receive gas discharged from at least the refrigeration compartment.