Sensor Head Bubble Reducer for Fluid Measurement Accuracy

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Solution Overview

Problem

Conventional fluid property sensors in vehicles, such as those measuring urea concentration in diesel exhaust fluid tanks, are impaired by air bubbles introduced during fluid recirculation, leading to measurement errors due to high temperature and pressure.

Innovation Solution

A bubble reducer device with a mesh or grid structure is integrated into the sensor head's opening, blocking bubbles in the fluid return line, reducing their collection at the fluid quality sensor and preventing measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fluid return line is used to recirculate excessive fluid back to the tank, then sufficient fluid supply to the consumer device is secured, but air bubbles are introduced into the tank causing measurement errors

Engineering Contradiction:
Improvefluid supply rateVSAvoidfluid quality measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

A bubble separator device is introduced as an intermediary component in the fluid return line. This device separates air bubbles from the recirculating fluid before it returns to the tank, preventing bubble contamination while maintaining the fluid recirculation function. The separator acts as a mediator between the recirculation system and the tank, eliminating the harmful effect of bubbles without compromising fluid supply.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If high temperature and pressure are used in the fluid recirculation system, then fluid delivery performance is improved, but air bubbles are generated and stick to sensors

Engineering Contradiction:
Improvefluid delivery powerVSAvoidair bubble generation
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The bubble separator device converts the harmful effect of air bubbles (generated by high temperature and pressure recirculation) into a manageable separation process. By designing the separator to exploit the compressibility and buoyancy differences between gas and liquid phases under high pressure conditions, the system transforms the bubble contamination problem into an efficient gas-liquid separation opportunity, maintaining high power delivery while eliminating bubbles.

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

3Measurement precision

If a bubble separator device is added to the sensor head, then measurement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvefluid quality measurement accuracyVSAvoidsensor head structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The bubble separator utilizes porous materials or mesh structures with specific pore sizes that allow liquid to pass through while blocking air bubbles. This approach achieves effective bubble separation without requiring complex mechanical components. The porous structure provides a simple, passive separation mechanism that integrates easily into the existing sensor head design, minimizing added complexity while maximizing measurement accuracy.

Inventive Principle:
Principle #31Porous materials

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 bubble reducer device effectively minimizes air bubbles in the tank and at the fluid quality sensor, ensuring accurate measurements and proper sensor functioning.

Implementation Method 1

A bubble reducer device provided at the opening, and configured to block bubbles in the fluid in the return line while the fluid passes through the bubble reducer device during operation

Methodology Applied
Scientific EffectPhysical barrier filtration: Filter (physical)

Data Source

PatentEP3771808B1Sensor head with return line
Publication Date: 2022.08.24 TE CONNECTIVITY NORGE AS
  • EP3771808B1 patent drawingFigure 1A~1C
  • EP3771808B1 patent drawingFigure 2~3
  • EP3771808B1 patent drawingFigure 4~5

AI summary

The invention provides a sensor head for being arranged in an orifice of a fluid tank with a bubble reducer device for blocking bubbles in a fluid in a return line for returning fluid to the fluid tank. Further, a corresponding fluid sensor comprising the sensor head and a selective catalytic reduction system comprising the fluid sensor is provided.