Rapid-Connect Coupler Vent-Stop for Safe Cryogenic De-Coupling
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Solution Overview
Problem
Existing couplers for cryogenic fluids, such as liquefied natural gas (LNG), face issues like freeze-up and leakage due to moisture, and are prone to forceful de-coupling, which can cause injury and equipment damage, especially during rapid and successive transfers in varying temperature environments.
Innovation Solution
A rapid-connect coupler with a stop apparatus that allows smooth transition between coupled and de-coupled configurations, featuring a probe assembly and housing barrel with a venting mechanism to prevent fluid communication and absorb venting forces, ensuring safe and efficient handling of cryogenic fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a rapid-connect coupler is used for quick transfers of cryogenic fluids, then productivity is improved, but the risk of freeze-up and leakage increases due to moisture in moist environments
Solution Approach 1:
The coupler is pre-chilled to cryogenic temperatures before use, and the sealing surfaces are designed to remain cold throughout the transfer process. This preliminary cooling action ensures that moisture does not have time to freeze on the sealing surfaces during the quick transfer operation, thus maintaining both high productivity and reliability.
Solution Approach 2:
The sealing surfaces are specifically designed with localized thermal insulation or heating elements in certain areas to prevent moisture condensation and freezing only where it matters most - at the sealing interfaces. This allows the bulk of the coupler to remain cold for efficient cryogenic fluid transfer while protecting critical sealing areas from freeze-up.
2Productivity
If multiple successive transfers are performed quickly, then productivity is improved, but the coupling head is prone to freeze-up and leakage
Solution Approach 1:
The coupler maintains continuous thermal contact with the cryogenic fluid throughout successive transfers, ensuring that the sealing surfaces remain cold and moisture-free. The design allows for rapid sequential connections without requiring reheating or thermal recovery between transfers, enabling continuous operation at high productivity while preventing ice formation.
Solution Approach 2:
The sealing surfaces are pre-coated with a protective layer or pre-chilled to such an extent that they can withstand multiple rapid transfers without moisture condensation and freezing. This beforehand preparation cushions against the harmful effects of repeated thermal cycling and moisture exposure during successive transfers.
3Productivity
If de-coupling is performed quickly, then productivity is improved, but remainder gas at high pressure causes forceful de-coupling that can result in injury
Solution Approach 1:
A vent channel is provided that extracts and vents the remainder gas from the coupling cavity before the coupling head can be fully removed. This extraction of the pressurized gas eliminates the source of the harmful recoil force, allowing for safe and rapid de-coupling operations that maintain high productivity without injury risk.
Solution Approach 2:
The vent channel acts as an intermediary pathway that provides a controlled route for the high-pressure remainder gas to escape. Instead of the gas being released suddenly and causing forceful de-coupling, the vent channel mediates the pressure release in a controlled manner, enabling safe rapid de-coupling while maintaining productivity.
Data Source
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AI summary
An embodiment includes a rapid-connect coupler (700) including a coupler body (702) configured to convey a fluid; a coupling head (701) at a first end of and communicating with the coupler body, the coupling head configured to transition between a coupled configuration and a de-coupled configuration. The coupler may further include a stop apparatus configured to allow the coupling head to transition from the de-coupled configuration to the coupled configuration without obstruction, and the stop apparatus may be configured to provide a hard-stop as the coupling head transitions from the coupled configuration to the de-coupled configuration.