Insulated Cryogenic Line Coupling for Quick Disconnect Isolation

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Solution Overview

Problem

Cryogenic fluid line couplings often lack thermal and electrical insulation, leading to freezing and increased fire risk due to oxygen condensation, and existing breakaway couplings are complex and difficult to insulate, while vacuum-insulated lines require non-conductive materials for electrical insulation which is challenging to maintain.

Innovation Solution

A coupling arrangement with thermally insulated casing and detachable connecting means that includes locking levers or clips for tool-free detachment, and provides electrical insulation between coupling parts and lines, using non-conductive materials and sealing mechanisms to prevent gas and fluid leakage, with optional gas displacement and pressure regulation to prevent oxygen condensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If rigid or flexible thermally insulated cables with vacuum insulation are used, then the surface temperature remains above oxygen condensation point, but couplings and connection components cannot be effectively insulated

Engineering Contradiction:
Improvesurface temperatureVSAvoidinsulation capability of couplings
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The coupling is divided into two separate halves (first coupling half and second coupling half) that can be connected without requiring complex insulation mechanisms. The segmentation allows each half to be simpler in design while maintaining thermal insulation through the overall coupling arrangement rather than requiring each component to be independently insulated.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A non-conductive coupling half serves as an intermediary component between conductive pipe sections. This non-conductive half provides both electrical insulation and a means to maintain thermal insulation, acting as a mediator that prevents oxygen condensation and electrical sparks without requiring complex vacuum insulation on the coupling itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If emergency disconnect couplings with complex release mechanisms are used, then line sections can be disconnected in emergencies, but the coupling becomes difficult to thermally insulate

Engineering Contradiction:
Improveemergency disconnect capabilityVSAvoidthermal insulation difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The coupling is segmented into two halves with a simplified connection interface. This segmentation allows for easier insulation compared to complex multi-component emergency disconnect mechanisms, while still enabling reliable connection and disconnection through the simplified half-coupling design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling design changes the structural parameters to use a simpler half-coupling configuration rather than complex release mechanisms. This parameter change maintains the ability to connect and disconnect line sections while significantly improving thermal insulation capability by reducing the number of components and complexity of the coupling structure.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If Johnston couplings with interlocking coupling halves are used, then thermal insulation can be provided, but the ability to quickly disconnect line sections is negatively impacted

Engineering Contradiction:
Improvethermal insulation capabilityVSAvoiddisconnection speed
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The coupling is divided into two separate halves that can be quickly connected and disconnected. This segmentation provides thermal insulation through the non-conductive material while maintaining fast disconnection capability, unlike interlocking designs that require complex engagement and disengagement mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The non-conductive coupling half acts as an intermediary that provides thermal insulation without requiring interlocking mechanisms. This intermediary component maintains insulation capability while enabling quick connection and disconnection through simpler joining methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If electrically conductive metals like stainless steel are used in vacuum-insulated pipes, then mechanical strength is improved, but electrical insulation becomes necessary and difficult to implement

Engineering Contradiction:
Improvemechanical strength of pipeVSAvoidelectrical insulation feasibility
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

A non-conductive coupling half serves as an electrical intermediary between conductive pipe sections. This intermediary provides the necessary electrical insulation to prevent sparks while maintaining mechanical connection, making electrical insulation feasible without compromising the mechanical strength of the stainless steel pipe components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Electrical insulation is applied locally at the coupling point rather than throughout the entire pipe system. The non-conductive coupling half provides localized insulation where electrical potential differences exist, while the conductive stainless steel pipe sections maintain their mechanical strength and conductivity where needed.

Inventive Principle:
Principle #3Local quality

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 solution effectively maintains the temperature above oxygen condensation point, prevents fluid leakage, and ensures electrical safety by providing reliable thermal and electrical insulation, reducing the risk of fire and damage during cryogenic fluid handling.

Implementation Method 1

vacuum-insulated cables with insulation that keeps the surface temperature of the cables and couplings consistently above the boiling point of oxygen

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

vacuum insulation with an inner and an outer tube, the space between which is evacuated

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Data Source

PatentEP3670998B1Coupling for fluid conduits
Publication Date: 2022.11.16 NEXANS SA
  • EP3670998B1 patent drawingFigure 1~2

AI summary

A coupling (100) for connecting thermally insulated fluid-carrying lines (102, 104) comprises a coupling (101) including a first (106) and a second coupling part (108) and connecting means (110) for connecting the two coupling parts (106, 108). A covering (112) enclosing the coupling (101) is provided, which rests against the thermal insulation of the fluid-carrying lines (102, 104) on both sides of the coupling (101). A cavity (114) formed by the covering (112) is provided for thermal insulation between the coupling (101) and the outer surface of the covering (112).