Pressure Surge Sensor With Retainer Piston for Low Pressure Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pressure surge detectors fail to reliably and quickly detect pressure surges at low pressures, particularly when the amount of pressurized gas released through a rupture disc is small, requiring operation at low pressures like 0.3 bar.

Innovation Solution

A gas pressure surge sensor with a retainer that restraints a piston member against movement, which is broken to release the piston upon a predetermined load, allowing the piston to move freely and vent excess pressure, using a magnetically actuated reed switch to generate an output signal when the pressure surge is detected.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional pressure surge detector is used, then the device structure is simple, but the sensor fails to operate reliably at low pressures

Engineering Contradiction:
Improvesensor operation reliabilityVSAvoidsensor structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The piston member is designed to be movable within the cylinder, transitioning from a restrained position to a free position in response to pressure changes. This dynamic mechanism enables the sensor to respond reliably to low pressure surges by allowing the piston to move and trigger the switch, while maintaining a simple overall structure through the use of basic mechanical components

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The piston member acts as an intermediary between the pressure surge and the reed switch. It translates the pressure differential into mechanical movement that actuates the magnetic switch, providing reliable detection at low pressures while keeping the structural complexity minimal through this simple mediation mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the retainer is designed to be strong to prevent false triggering, then the sensor reliability improves, but the response time to pressure surge decreases

Engineering Contradiction:
Improvefalse triggering preventionVSAvoidpressure surge response time
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The retainer is designed with specific mechanical properties - strong enough to prevent accidental or false triggering under normal conditions, but with a predetermined failure load that allows it to break and release the piston when subjected to a genuine pressure surge. This parameter optimization enables both reliability and quick response

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the piston is restrained to prevent movement, then the sensor avoids false signals, but the detection capability at low pressure is reduced

Engineering Contradiction:
Improvepressure surge detection accuracyVSAvoidrestraint mechanism complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The piston member serves as an intermediary that translates subtle pressure changes into measurable mechanical displacement. It is restrained by a simple retainer mechanism that allows precise detection of low pressure surges while maintaining measurement accuracy through the piston's controlled movement and magnetic coupling with the reed switch

Inventive Principle:
Principle #24Intermediary (Mediator)

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 sensor operates reliably and simply at low pressures, providing a quick and accurate detection of pressure surges, ensuring safe operation by generating a warning signal or controlling the apparatus when the rupture disc ruptures.

Implementation Method 1

a magnet, its movement being sensed by a non-invasive sensor

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

using a magnetically actuated reed switch to generate an output signal

Methodology Applied
Scientific EffectMagnetic actuation: Magnetism

Data Source

PatentEP2177799B1Pressure surge sensor and assembly including such a sensor and a rupture disc
Publication Date: 2014.02.26 ELFAB LTD
  • EP2177799B1 patent drawingFigure 1~3
  • EP2177799B1 patent drawingFigure 4
  • EP2177799B1 patent drawingFigure 5

AI summary

A pressure surge sensor has a body (10) having a cylinder passage (13), a magnetically actuated electrical switch (17) mounted on the body, and a piston member (20) movable along the passage relative to the switch. The piston member carries a magnet. When the cylinder passage (13) is coupled to a fluid pressure surge source, a fluid pressure surge applied causes the piston member to move along the cylinder passage relative to said switch, thereby actuating the switch. A breakable retainer element restrains the piston member against movement, and the piston is freely movable along the cylinder passage, after release by the retainer. The pressure surge sensor is suitable to be arranged downstream of a rupture disc, which releases overpressure of a pressurised apparatus, for example an extrusion apparatus, or a gas handling or gas storage system.