Open Cross-Section Shielding Conductor for Radar Level Gauge

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Solution Overview

Problem

Existing guided wave radar level gauge systems with two-conductor probes face challenges with viscous and sticky liquids, which can clog the probe and require cumbersome spacer arrangements, limiting their application range.

Innovation Solution

A two-conductor probe with a rigid shielding conductor having an open cross-section profile and spacer arrangements, allowing for easier cleaning and spacer attachment, facilitating use with a broader range of products and reducing clogging risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coaxial probe with holes in the shielding conductor is used, then the probe can maintain structural integrity and provide shielding, but viscous and sticky liquids can clog the holes and fill the space between conductors

Engineering Contradiction:
Improveprobe functionalityVSAvoidapplicability to different products
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The shielding conductor is designed with an open cross-section profile featuring longitudinal openings that allow liquid to pass through freely. This porous-like structure prevents clogging by viscous and sticky liquids while maintaining the shielding function, as the openings enable continuous product flow through the probe structure.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The shielding conductor transitions from a traditional closed circular cross-section to an asymmetric open cross-section with longitudinal openings. This asymmetric design with enclosing arc angles between 180° and 330° provides both shielding capability and anti-clogging properties by allowing liquid to flow through the openings rather than getting trapped.

Inventive Principle:
Principle #4Asymmetry

2Stability of the object's composition

If spacers are arranged to maintain positional relationship between signal conductor and shielding conductor, then the probe structure is stabilized, but the arrangement process becomes cumbersome and time-consuming

Engineering Contradiction:
Improvepositional stabilityVSAvoidassembly ease
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The spacer and the shielding conductor are merged into a single integrated component. The spacer elements are directly formed as part of the shielding conductor structure, eliminating the need for separate spacer arrangements and simplifying the assembly process while maintaining positional stability between the signal conductor and shielding conductor.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shielding conductor serves multiple functions simultaneously: it provides electromagnetic shielding, maintains structural stability, and acts as its own spacer through integrated spacer elements. This multi-functionality reduces the number of separate components needed and simplifies the overall probe assembly.

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

3Reliability

If a closed circular cross-section shielding conductor is used, then the probe provides complete shielding, but cleaning becomes difficult and clogging occurs with viscous liquids

Engineering Contradiction:
Improveshielding effectivenessVSAvoidcleaning ease
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The shielding conductor features longitudinal openings creating a porous-like structure that allows liquid to flow through freely. This design enables easy cleaning by preventing liquid accumulation while maintaining sufficient shielding effectiveness through the enclosing arc profile that provides electromagnetic containment.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

Portions of the traditional closed circular shielding conductor are extracted or removed to create longitudinal openings. This extraction of material from the closed cross-section allows liquid to pass through the probe structure, facilitating cleaning and preventing clogging while retaining shielding capability through the remaining enclosing arc structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution enables the use of the radar level gauge system in situations previously unsuitable, simplifying installation and maintenance while minimizing clogging and reflection issues, especially in high-temperature, high-pressure applications.

Implementation Method 1

an elongated two-conductor probe (7) having a signal conductor (49) connected to the transceiver (17), and a rigid shielding conductor (51) spaced apart from the signal conductor (49) by an open space, the two-conductor probe (7) extending from an upper probe end to a lower probe end for guiding an electromagnetic transmit signal from the transceiver (17) along the two-conductor probe (7) towards and into the product (3) in the tank, and for returning an electromagnetic surface echo signal resulting from reflection of the transmit signal at a surface of the product (3) back towards the transceiver (17)

Methodology Applied
Scientific EffectElectromagnetic signal propagation: Electromagnetic Induction

Data Source

PatentEP3425351B1Radar level gauge system having longitudinally open two-conductor probe, and method of assembly of the level gauge system
Publication Date: 2022.06.29 ROSEMOUNT TANK RADAR
  • EP3425351B1 patent drawingFigure 1~2
  • EP3425351B1 patent drawingFigure 3
  • EP3425351B1 patent drawingFigure 4~5

AI summary

A radar level gauge system comprising a transceiver; an elongated two-conductor probe having a signal conductor connected to the transceiver, and a rigid shielding conductor spaced apart from the signal conductor by an open space. The two-conductor probe extends from an upper probe end to a lower probe end; and processing circuitry for determining the filling level based on a transmit signal and a surface echo signal. The shielding conductor exhibits an open cross-section profile, in a cross-section with a plane perpendicular to the two-conductor probe, along at least a portion of the two-conductor probe. The two-conductor probe further comprises a plurality of spacer arrangements. Each spacer arrangement includes at least a first spacer member attached to the rigid shielding conductor and arranged between the signal conductor and the rigid shielding conductor for preventing contact between the signal conductor and the shielding conductor.