Eccentric Clamp Assembly for Sensing Line Vibration Dampening

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current systems for dampening vibrations in sensing lines within nuclear reactor pressure vessels require precise measurements, are custom-made, and increase installation time and operator exposure to radioactivity, while also potentially deflecting the sensing lines.

Innovation Solution

The implementation of an eccentric clamp assembly (ECA) that engages a mount on the structure, comprising a key member, eccentric member, cam member, and clamp member, allowing for adjustable engagement and reduced vibration levels without deflecting the sensing line, and can be adapted to various configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If custom-made dampening systems with precise measurements are used, then vibration dampening effectiveness is improved, but installation time and operator exposure to radioactivity increase

Engineering Contradiction:
Improvevibration dampening effectivenessVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The dampening system is divided into modular components: a clamp assembly that attaches to the diffuser, a sensing line clamp, and an adjustable positioning mechanism. This segmentation allows each component to be independently manufactured and assembled, eliminating the need for custom-made systems while maintaining effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system incorporates an adjustable mechanism that allows the sensing line position to be dynamically modified during installation. This dynamic adjustment capability enables the system to adapt to various configurations without requiring precise pre-measurements, reducing installation time while maintaining vibration dampening effectiveness.

Inventive Principle:
Principle #15Dynamics

2Reliability

If additional support blocks are added to dampen vibration, then vibration control is improved, but the sensing line may be deflected

Engineering Contradiction:
Improvevibration controlVSAvoidsensing line position
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

The dampening force is applied locally at the clamp assembly attachment point rather than through distributed support blocks along the sensing line. This localized approach provides vibration control while minimizing the risk of deflection along the entire sensing line length.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The clamp assembly acts as an intermediary component between the diffuser and the sensing line, providing vibration dampening through controlled mechanical coupling while allowing the sensing line to maintain its proper alignment and position.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If standard clamp assemblies are used instead of custom-made systems, then ease of manufacture and installation are improved, but adaptability to various configurations may be reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidconfiguration adaptability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The clamp assembly includes adjustable positioning mechanisms and flexible mounting options that allow standard manufactured components to adapt to various sensing line configurations and diffuser geometries, maintaining versatility without requiring custom fabrication.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clamp assembly is designed as a universal component that can be applied to different sensing line sizes, diffuser types, and installation locations. This multi-functionality allows a single standard design to replace multiple custom-made systems while maintaining adaptability to various configurations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 ECA system effectively reduces vibration levels and changes the natural frequency of the sensing line, preventing resonance and cyclic fatigue cracking, thereby reducing the risk of equipment failure and plant shutdown, while minimizing installation time and operator exposure to radioactivity.

Implementation Method 1

an eccentric member comprising: a base comprising a center, wherein the base engages the mount; a shaft, wherein an aft end of the shaft is eccentrically attached to the base

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Implementation Method 2

a system for dampening the vibration experienced by a line integrated with a structure

Methodology Applied
Scientific EffectVibration dampening: Damping

Implementation Method 3

The ECA system effectively reduces vibration levels and changes the natural frequency of the sensing line, preventing resonance and cyclic fatigue cracking

Methodology Applied
Scientific EffectResonance prevention: Resonance

Data Source

PatentEP2128504B1System for dampening the vibration experienced by a line
Publication Date: 2012.11.07 GE HITACHI NUCLEAR ENERGY AMERICAS LLC
  • EP2128504B1 patent drawingFigure 1
  • EP2128504B1 patent drawingFigure 2
  • EP2128504B1 patent drawingFigure 3

AI summary

A system for dampening the vibrations experienced by a sensing line (110) connected to a jet pump (105) within a nuclear reactor pressure vessel. The system may include an eccentric clamp assembly (ECA) 200. The ECA (200) includes: a cam member (230) and saddle (250); a key member (220), such as a t-bolt; an eccentric member (230); a clamp member (240); clamp body. A jacking bolt (260), washers (280), and an ECA (200) connector (270) lock the assembly in place. The ECA (200) allows for adjustment in multiple directions, reducing installation time.