Regulating Valve Trim with Labyrinth Grooves for Contaminated Fluids

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Solution Overview

Problem

Conventional control valves face challenges in handling contaminated fluids with large pressure drops, leading to clogging, erosion, and cavitation due to fixed geometry flow paths that cannot adapt to varying shutter strokes, resulting in suboptimal flow control and potential damage.

Innovation Solution

The solution involves a trim design with a fixed number of fluid paths whose cross-sectional area changes continuously with the shutter lift, featuring tortuous paths and labyrinth grooves to reduce leakage and velocity peaks, ensuring effective particle transport and preventing erosion, while maintaining control accuracy and rangeability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fixed geometry flow paths are used in control valves, then the valve structure is simple and easy to manufacture, but the valve cannot handle contaminated fluids effectively and suffers from clogging, erosion, and cavitation

Engineering Contradiction:
Improvevalve performance with contaminated fluidsVSAvoidtrim design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the flow path geometry adaptive to the shutter stroke position. The tortuous paths are designed to change their effective cross-sectional area continuously as the shutter moves, allowing the flow characteristics to dynamically adjust rather than remain fixed. This enables the valve to maintain reliable performance with contaminated fluids across varying operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a new dimension to the flow path design by creating three-dimensional tortuous paths that wind through the trim assembly. Instead of simple linear or radial paths, the fluid must navigate complex spatial routes with multiple direction changes, which reduces velocity peaks and prevents direct impact on the shutter, thereby preventing erosion and cavitation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If multiple fixed geometry flow paths are used to increase flow rate, then the flow capacity increases, but the velocity distribution becomes uneven causing erosion and cavitation at the shutter

Engineering Contradiction:
Improveflow rateVSAvoiderosion and cavitation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs curved and winding flow paths instead of straight lines. The tortuous geometry causes the fluid to follow smooth curved trajectories with multiple direction changes, which distributes velocity more evenly and eliminates concentrated high-velocity jets that would otherwise strike the shutter directly, preventing erosion and cavitation while maintaining high flow capacity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent converts the potentially harmful high velocity of fluid into a beneficial feature by routing it through extended tortuous paths. The kinetic energy that would cause damage is dissipated through gradual direction changes and friction along the winding path, while the extended path length maintains overall flow capacity. The harmful velocity peak is transformed into a controlled, distributed flow pattern.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If wide flow paths are used to allow debris passage, then clogging is prevented, but flow control accuracy and rangeability are reduced

Engineering Contradiction:
Improveresistance to cloggingVSAvoidflow control accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by creating different flow path characteristics in different regions of the trim. The tortuous paths have varying cross-sectional areas, curvature radii, and direction change angles at different locations. This allows the valve to maintain wide effective paths for debris passage in some regions while creating controlled constriction zones that provide precise flow control authority in other regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by varying the geometric parameters of the tortuous paths along their length. The cross-sectional area, path curvature, and direction change angles are continuously modified along the flow path, enabling the valve to achieve both debris tolerance and precise flow control through a single integrated design rather than requiring separate wide and narrow sections.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the number of fluid paths is increased to increase flow capacity, then productivity improves, but the complexity of the trim design and manufacturing increases

Engineering Contradiction:
Improveflow capacityVSAvoidtrim manufacturing
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent merges multiple flow path functions into a single integrated tortuous path structure. Instead of providing separate straight flow channels that would require multiple precision-machined components, the design combines the flow capacity of multiple paths into one continuous winding path that can be manufactured as a single piece or fewer components, simplifying manufacturing while maintaining high flow capacity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent resolves the manufacturing complexity issue by moving from a two-dimensional arrangement of multiple parallel paths to a three-dimensional single tortuous path. The winding path utilizes the third dimension (axial direction) to provide extended flow length and capacity without requiring multiple radial or circumferential channels, thereby reducing the number of machining operations and assembly steps required.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4108961B1Control element for a regulating valve
Publication Date: 2024.04.03 CCI ITAL SRL
  • EP4108961B1 patent drawingFigure 1~2
  • EP4108961B1 patent drawingFigure 3~4c
  • EP4108961B1 patent drawingFigure 5~6

AI summary

Pressure control element (10) for a fluid regulating valve having: - a resistor (3), a stationary element that has a plurality of cavities (31a) having a plurality of fixed coupling surfaces (31A), - a shutter (2), a movable element that has a plurality of projecting walls (21) having a plurality of movable coupling surfaces (21a), wherein the movable coupling surfaces (21a) couple with corresponding fixed coupling surfaces (31A) defining at least one tortuous path (31) of the fluid, wherein - the number of the at least one tortuous path (31) of the fluid is fixed while its cross section is continuously modified as the position of the shutter varies, and wherein - a plurality of labyrinth grooves (23, 32) is formed on the fixed coupling surfaces (31A) of the tortuous path (31) of the resistor (3) and/or on the movable coupling surfaces (21a) of the projecting walls (21) of the shutter (2) and said plurality of labyrinth grooves (23, 32) being made from rectilinear grooves obtained in the fixed coupling surfaces (31A) of the resistor (3) and/or in the movable coupling surfaces (21a) of the shutter (2) and being perpendicular to the flow direction.