Cryogenic Pipe Joint Sealing With Interseal Overpressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing articulated pipe connection devices for low-temperature liquids, such as cryogenic gases, face significant risks of primary seal damage due to gas expansion when heated, especially with larger diameter seals, as small gas leaks can cause significant damage during temperature changes.
Innovation Solution
The pipe connection device incorporates an overpressure channel connecting the space between the primary and secondary seals, allowing for an overpressure higher than the interior pressure, which prevents gas from reaching the primary seal during operation, and includes a pressure-generating device and control system to manage this overpressure, ensuring the primary seal withstands external pressures independently of interior conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a primary seal is used in the pipe connection device, then sealing effectiveness is improved, but the risk of seal damage from expanding gas increases
Solution Approach 1:
The sealing system is divided into two independent seals: a primary seal (30) for main sealing function and a secondary seal (34) for backup protection. The space between them is segmented and connected to overpressure channel (36), creating a protected zone that prevents gas expansion from reaching the primary seal.
Solution Approach 2:
An overpressure channel (36) is pre-established connecting the space between primary and secondary seals to the exterior. A pressure-generating device is ready to apply overpressure before gas expansion occurs, preventing liquid gas from reaching and damaging the primary seal during temperature changes.
2Reliability
If the primary seal is designed to withstand constant high internal pressures, then sealing reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The overpressure channel (36) and pressure-generating device act as an intermediary system between the interior pressure and the primary seal (30). This mediator applies external overpressure to counterbalance internal pressure, allowing the primary seal to operate under reduced stress conditions while maintaining reliable sealing.
Solution Approach 2:
The pressure conditions acting on the primary seal are changed by introducing overpressure from the pressure-generating device. Instead of the seal withstanding only high internal pressure, the parameter is modified to include a balanced pressure state where external overpressure compensates for internal pressure, reducing the net stress on the seal.
3Ease of operation
If small amounts of liquid gas penetrate into the chamber with the secondary seal, then operation continues normally, but seal damage occurs during heating to ambient temperature
Solution Approach 1:
The overpressure channel (36) provides beforehand cushioning by maintaining a pressure barrier that prevents liquid gas from reaching the primary seal. The pressure-generating device is prepared in advance to counteract any pressure changes during heating, protecting the primary seal from damage even if minor leaks occur during operation.
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
This solution effectively prevents damage to the primary seal by maintaining a higher external pressure, reducing the risk of seal failure and allowing for simpler, cost-effective design of the primary seal, as it does not need to withstand constant high internal pressures.
Implementation Method 1
An overpressure can be applied to the groove with the aid of a pressure-generating device, which is connected to the overpressure channel, so that overpressure prevails in the space between the primary and secondary seals
Implementation Method 2
A pressure-generating device is connected to the overpressure channel, which can generate an overpressure as a function of the pressure in the interior of the pipe connection device
Data Source
Figure 1~2
Figure 3
AI summary
A pipe connection for joining pipes for transporting low-temperature liquids has two connecting elements (10, 12) for connecting to each pipe end. Each connecting element (10, 12) is connected to a bearing element (16, 18). Furthermore, an inner part (26) is provided which, together with the two connecting elements (10, 12), forms an interior space (26). In addition to an inwardly open groove (28) in which a primary seal (30) is arranged, a circumferential, self-contained chamber (32) is provided in which a secondary seal (34) is arranged. The groove (28) is connected to a pressure relief channel (36). Overpressure can be generated on an outer surface (38) of the primary seal (30) via the pressure relief channel (36) by means of a pressure generation device.