Laser-Defined Rupture Disc Opening for Anti-Fragmentation Control
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Solution Overview
Problem
Existing rupture discs face limitations in control over opening characteristics due to work hardening and stress zones from metal scoring dies, and difficulties in achieving precise control over line depth and width, especially in forming complex structures with multiple trenches close together.
Innovation Solution
A laser-formed line of opening with disc opening control features, including converging lased side margins and anti-fragmentation features, is created using laser ablation to form trenches with varying degrees of superposition and divergence, allowing for precise control over the opening characteristics and preventing fragmentation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal scoring dies are used to form score lines, then the disc opens at the defined line, but work hardening increases brittleness and creates stress zones that limit service life
Solution Approach 1:
The patent replaces the mechanical scoring die process with a laser-based process to form the line of opening. The laser creates a controlled heat-affected zone and melts material to form a precise line of opening without the mechanical contact and work hardening associated with scoring dies. This substitution eliminates the creation of stress zones and brittleness while maintaining precise control over the opening location.
Solution Approach 2:
The patent changes the physical state and properties of the disc material through controlled laser heating. By adjusting laser parameters (power, speed, pulse duration), the process creates a specific heat-affected zone depth and width that controls where opening occurs without causing excessive brittleness. The thermal parameters are optimized to achieve the desired line of opening characteristics while minimizing adverse effects on material properties.
2Manufacturing precision
If metal scoring dies are used, then the score line is formed, but die wear makes it difficult to control the depth of the score
Solution Approach 1:
The patent replaces the mechanical scoring die with a laser system that has no physical contact with the disc surface during the scoring process. This eliminates die wear entirely, as the laser beam does not degrade through use. The depth of the line of opening is controlled through laser parameters (power, speed, focus position) rather than mechanical die geometry, providing consistent precision throughout production without periodic die replacement or reconditioning.
3Adaptability or versatility
If conventional continuous trenches are used, then the line of weakness is formed, but the range of burst pressures is limited
Solution Approach 1:
The patent segments the continuous line of opening into multiple discrete sections or trenches of varying depths, widths, and spacings. This segmented configuration allows different portions of the line to initiate opening at different pressures, thereby expanding the range of achievable burst pressures. The segmentation approach maintains relative simplicity while providing enhanced adaptability compared to conventional uniform continuous trenches.
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 approach enhances control over the opening characteristics of rupture discs, reducing fragmentation and improving the reliability of pressure relief devices by allowing for more precise control over the opening process and preventing stress zones, thus extending the service life.
Implementation Method 1
A laser is then used to remove a portion of the resist material corresponding to the desired line of weakness. Next, the disc undergoes an electropolishing operation to remove metal from the surface of the disc thereby forming a line of weakness having a desired depth.
Data Source
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AI summary
A rupture disc (10) is provided comprising a line of opening (16) formed in at least one face thereof. The line of opening (16) is formed by laser machining of the disc's face and includes at least one disc opening control feature (20). The disc opening control feature (20) may be an opening-initiation feature configured to assist with initial rupture of the disc (10). Alternatively, the opening control feature (20) may be an anti-fragmentation feature configured to dissipate the energy acting upon the disc (10) so as to prevent separation of the petal formed upon opening of the disc.