Feedwater Sparger Pipe Vibration Dampening Clamp

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Solution Overview

Problem

Current systems for dampening vibration in nuclear reactor pressure vessel piping, such as re-welding, are time-consuming and expose operators to radioactivity, and often lead to repeat failures.

Innovation Solution

A repair clamp system that provides support and preload to the feedwater sparger pipe, altering its natural frequencies to prevent resonance, comprising an upper and lower section with crimp collars, jacking bolts, and pinch bolts to secure the pipe without welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If re-welding is used to dampen vibration, then vibration control is improved, but installation time increases and operator exposure to radioactivity increases

Engineering Contradiction:
Improvevibration controlVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the welding process (thermal/mechanical system) with a mechanical clamping system. The clamp assembly uses bolts and clamping force to secure the sparger pipe, eliminating the need for welding operations. This substitution reduces installation time and operator exposure to radioactivity while maintaining vibration control effectiveness through mechanical preload application.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the method of applying force to the pipe from thermal welding to mechanical clamping with adjustable preload. By using bolts that can be tightened to specific torque values, the system allows for precise control of clamping force parameters, achieving vibration dampening without the time-consuming welding process.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If re-welding is used to dampen vibration, then vibration control is improved, but operator exposure to radioactivity increases

Engineering Contradiction:
Improvevibration controlVSAvoidoperator exposure to radioactivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces welding operations with mechanical clamping, eliminating the need for operators to perform welding tasks inside the reactor pressure vessel. This reduces radiation exposure by removing a complex thermal process and replacing it with simpler mechanical assembly that can be completed more quickly with less operator presence in the radiative environment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If a clamp system is used to dampen vibration, then installation time is reduced, but device complexity increases

Engineering Contradiction:
Improveinstallation speedVSAvoidclamp system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the clamp system into modular components: a clamp body, separate bolt assemblies, and positioning elements. This segmentation allows for pre-fabrication of standardized parts that can be quickly assembled on-site, reducing installation time while managing complexity through modularity and standardization of components.

Inventive Principle:
Principle #1Segmentation

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

Reduces vibration amplitude and frequency, reduces installation time, and minimizes operator exposure to radioactivity by providing a secure, adjustable clamp system that maintains preload and prevents loosening.

Implementation Method 1

A repair clamp system that provides support and preload to the feedwater sparger pipe, altering its natural frequencies to prevent resonance

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

apparatus for dampening vibration experienced by a sparger pipe

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

comprising an upper and lower section with crimp collars, jacking bolts, and pinch bolts to secure the pipe without welding

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2236883B1Apparatus and system for dampening the vibration experienced by a sprager pipe
Publication Date: 2014.12.10 GE HITACHI NUCLEAR ENERGY AMERICAS LLC
  • EP2236883B1 patent drawingFigure 1
  • EP2236883B1 patent drawingFigure 2
  • EP2236883B1 patent drawingFigure 3A~3B

AI summary

An embodiment of the present invention may reduce the level of vibration experienced by a line, such as, but not limiting of, a pipe, a cable, tubing, or the like, that is connected to at least one separate structure. For example, but not limiting of, the structure includes: a reactor pressure vessel (10), a feedwater sparger pipe (20), steam generator, a pipe, a pressure vessel, a heat exchanger, a pump, a condenser, a tank, or the like. An embodiment of the present invention may provide support and a preload to the line at a new location or may replace an existing support, such as, but not limiting of, a weld; which may alter the natural frequencies to avoid resonance from occurring when the structure(s) is excited.