Valve Damping with Elastomeric Element for Low Flow Control

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Solution Overview

Problem

Existing control valves face challenges in achieving stable fluid control at low flow rates, particularly in regulating heat transfer fluids in heat exchangers, where conventional damping devices fail to provide precise control due to insufficient force increase near the valve seat.

Innovation Solution

The use of an elastomeric element with a predetermined profile surface, which compresses disproportionately as the valve element approaches the valve seat, generating a progressive increase in force, replaces conventional springs, allowing for stable flow control by increasing the force required for closure disproportionately at low flow rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional spring is used as a damping device, then the valve element can be moved freely, but stable control at low flow rates cannot be achieved because the force increase is linear and insufficient near the valve seat

Engineering Contradiction:
Improvestable control at low flow ratesVSAvoidforce required for valve element movement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the force-displacement parameter relationship by replacing the linear spring characteristic with a non-linear elastomeric element. The elastomeric element's force increases disproportionately with compression distance, creating a progressive valve characteristic that provides stable control at low flow rates while maintaining ease of operation across the full range.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses an elastomeric material with specific viscoelastic properties to create a damping device that combines cushioning effects with progressive force generation. This composite material approach allows the valve to achieve both soft initial closure and increased force near the seat, resolving the contradiction between ease of operation and stable low-flow control.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If the valve element approaches the valve seat with constant force, then movement is easy, but flow control precision deteriorates at low flow rates

Engineering Contradiction:
Improveflow control precisionVSAvoidforce required for closure
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The patent implements a dynamic force characteristic where the closing force is not constant but varies with the valve element's position. The elastomeric element provides low initial force for easy movement, then progressively increases force as the valve approaches the seat, enabling precise flow control at low rates without requiring excessively high force throughout the entire stroke.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastomeric element is pre-compressed to a predetermined extent before the valve element reaches the valve seat. This preliminary compression action allows the element to generate increasing counterforce progressively, ensuring that precise control is achieved at the critical low-flow stage without requiring the valve element to overcome excessive force throughout the entire closing process.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a linear spring provides damping force, then the structure is simple, but progressive valve characteristic cannot be achieved

Engineering Contradiction:
Improveprogressive valve characteristicVSAvoiddamping device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the conventional mechanical spring system with an elastomeric element that utilizes material elasticity and viscoelasticity to generate the required force characteristics. This substitution maintains structural simplicity while achieving the progressive valve characteristic, as the non-linear force generation is inherent to the elastomeric material properties rather than requiring complex mechanical linkages.

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

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 enables stable and precise control of fluid flow at low rates by ensuring a larger temperature change is required for flow adjustments, maintaining control valve accuracy and efficiency.

Implementation Method 1

The spring or restoring action of this element results from the elastomeric material from which the element is formed

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

An element (23, 24) made of elastomeric material, which surrounds the valve spindle (4) and interacts with a surface (26, 27) with a predetermined profile transversely to the direction of movement of the valve element (3)

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP1979661B1Valve
Publication Date: 2011.05.25 DANFOSS AS
  • EP1979661B1 patent drawingFigure 1
  • EP1979661B1 patent drawingFigure 2

AI summary

Specified is a valve having a valve seat, having a valve element (3) which interacts with the valve seat and is moveable in a valve housing (11) over a predetermined movement path, and having a damping device (22) which acts on the valve element (3) at least on a part of the movement path. It is sought to obtain stable control of a fluid even at a low throughflow rate. It is provided for this purpose that the damping device (22) has at least one element (23, 24) made from an elastomeric material which can be compressed between a first stop (16), which is connected to the valve element, and a second stop (28), which is connected to the valve housing (11).