Multivariable Guided Wave Radar Probe for Fluid Level Detection

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Solution Overview

Problem

Guided wave radar systems for fluid level detection in tanks face inaccuracies due to factors like errant transmission, improper installation, changes in tank pressure, temperature, fluid flow rate, concentration, and density, especially when measuring fluids with low dielectric constants, leading to false alarms and unnecessary stoppages.

Innovation Solution

A multivariable fluid level detection system that integrates a force sensor into the guided wave radar probe to measure additional parameters such as force or acceleration, combined with microwave pulse transmission and reception, to improve measurement accuracy by accounting for these factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple radar signals through one or multiple transceivers are used to calculate multiple tank levels for comparison, then detection of radar component failure is improved, but the system remains susceptible to distortion-causing system factors such as pressure, temperature, and fluid property changes

Engineering Contradiction:
Improvedetection of radar component failureVSAvoidaccuracy of level calculation
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent combines multiple sensing capabilities (radar level detection, pressure sensing, temperature sensing, and fluid property detection) into a single integrated probe assembly. This merging allows the system to simultaneously measure multiple parameters and compensate for their相互 influences, thereby improving both reliability and measurement precision by addressing distortion factors at their source rather than relying solely on redundant radar transceivers

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If individual, non-integral pressure sensors are added at fixed locations, then some compensation for pressure effects is achieved, but installation becomes difficult and expensive requiring additional tank modifications

Engineering Contradiction:
Improvecompensation for pressure effectsVSAvoidinstallation complexity and cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent integrates pressure sensors, temperature sensors, and radar transceivers into a single probe assembly that can be installed through a single tank opening. This eliminates the need for multiple separate installations and additional tank modifications, significantly reducing installation complexity and cost while maintaining the ability to compensate for pressure and temperature effects on level measurements

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The probe assembly serves multiple functions simultaneously: it performs radar level detection, pressure measurement, temperature measurement, and fluid property detection all through a single integrated unit. This multi-functionality eliminates the need for separate sensors and installations for each measurement type, thereby improving ease of manufacture and installation while comprehensive measurement capabilities

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

3Measurement precision

If a force sensor is integrated into the probe assembly, then measurement accuracy is improved by accounting for probe movement and acceleration, but device complexity increases

Engineering Contradiction:
Improveaccuracy of level measurementVSAvoidcomplexity of probe assembly
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent integrates force sensors, acceleration sensors, pressure sensors, temperature sensors, and radar transceivers into a single multi-functional probe assembly. By merging these components, the system achieves comprehensive measurement capabilities (level, pressure, temperature, probe movement, acceleration) while consolidating what would otherwise be multiple separate devices into one unified installation, thereby managing device complexity through integration rather than multiplication of separate components

Inventive Principle:
Principle #5Merging (Combining)

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 system provides more accurate and dependable fluid level measurements by integrating sensors into the probe, reducing the need for external sensors and tank modifications, thus lowering costs and minimizing false alarms and process interruptions.

Implementation Method 1

A guided wave radar tank probe is inserted into a tank from the top and submerged into process fluids. The probe is then used to send guided electromagnetic waves into the fluid or fluids contained within the tank.

Methodology Applied
Scientific EffectGuided wave radar: Radar

Implementation Method 2

Reflection occurs when the waves encounter a fluid with a different dielectric constant. At this point, part of the energy will be reflected back in the form of a reflected wave.

Methodology Applied
Scientific EffectElectromagnetic wave reflection: Reflection

Implementation Method 3

The speed of the wave and the strength of the wave reflection are dependent on the dielectric constant of the fluid(s) through which the wave travels.

Methodology Applied
Scientific EffectDielectric constant: Dielectric Permittivity

Implementation Method 4

a first sensor integral to the probe assembly for producing a first sensor signal that is a function of a first sensed parameter... The first sensor comprises a force sensor and the first sensed parameter is force or acceleration of the probe

Methodology Applied
Scientific EffectForce sensing: Force

Data Source

PatentEP3201578B1Multivariable guided wave radar probe
Publication Date: 2022.11.30 ROSEMOUNT INC
  • EP3201578B1 patent drawingFigure 1
  • EP3201578B1 patent drawingFigure 2
  • EP3201578B1 patent drawingFigure 3

AI summary

A multivariable fluid level detection system (10) comprising a guided wave radar probe (20) with sensor or sensors (24a-24n) integral to the probe (28) for producing sensor signal(s), a transmitter (44) for transmitting guided microwave pulses down the probe (28), a receiver (46) for receiving reflected microwave pulses, and a processor (52) for producing a measurement of fluid level based upon a time difference between transmission of a pulse and receipt of a reflected pulse and the sensor signal(s).