Capacitive Fluid Detection for Unobstructed Low-Flow Sensing

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Solution Overview

Problem

Existing fluid detection systems for backflow prevention devices face challenges such as probe obstruction in discharge flow paths, limited configuration flexibility in confined spaces, and difficulty in detecting small fluid flows.

Innovation Solution

A fluid detection system that includes a sensor module with a sensor element configured to detect capacitance within a liquid flow path without obstructing the flow, allowing for installation in various orientations and effectively detecting small fluid flows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If probes are used to detect fluid flow in discharge pipe, then fluid detection capability is achieved, but discharge flow path is obstructed

Engineering Contradiction:
Improvefluid detection capabilityVSAvoiddischarge flow path clearance
Core Design Contradiction:
Difficulty of detecting and measuringVSProductivity

Solution Approach 1:

The patent uses the discharge pipe wall as an intermediary medium to transmit fluid flow information from the discharge flow path to the sensor element. The sensor detects vibrations or acoustic signals through the pipe wall without direct contact with the fluid, thus maintaining flow path clearance while achieving detection capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact probes with a non-contact sensing mechanism that detects fluid flow through vibrations or acoustic signals transmitted through the pipe wall, eliminating the need for physical obstruction in the flow path

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

2Volume of moving object

If discharge pipe is configured in confined mechanical room, then space utilization is improved, but sensor installation flexibility is reduced

Engineering Contradiction:
Improvespace utilizationVSAvoidsensor installation flexibility
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The sensor module is designed with universal mounting capabilities that allow it to be installed in various orientations and configurations. The sensor can detect fluid flow through the pipe wall regardless of the pipe's orientation or the sensor's specific position, providing adaptability to confined space constraints

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

Solution Approach 2:

The patent transitions from requiring direct fluid contact (one-dimensional insertion into flow path) to detecting through the pipe wall (adding a spatial dimension), allowing sensor installation on the exterior surface of the discharge pipe in confined spaces without obstructing the flow path

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

3Measurement precision

If conventional sensors are used in discharge pipe, then fluid detection is achieved, but small fluid flows cannot be detected

Engineering Contradiction:
Improvefluid flow detection thresholdVSAvoidsmall fluid flow detection capability
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent utilizes mechanical vibrations induced by fluid flow in the discharge pipe as the detection mechanism. Even small fluid flows generate detectable vibrations in the pipe wall, allowing the sensor to detect low-flow conditions that conventional sensors would miss

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the detection parameter from direct fluid contact measurements to vibration/acoustic signal measurements through the pipe wall. This parameter change enables detection of small fluid flows by amplifying the mechanical effects of flow through the pipe structure

Inventive Principle:
Principle #35Parameter changes

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 unobstructed fluid flow detection, enhances configuration flexibility, and improves the ability to detect small fluid flows, thereby addressing the limitations of existing technologies.

Implementation Method 1

the sensor element is configured to detect capacitance within a liquid flow path

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4260038B1Fluid detection system
Publication Date: 2025.02.05 WATTS REGULATOR CO
  • EP4260038B1 patent drawingFigure 1
  • EP4260038B1 patent drawingFigure 2
  • EP4260038B1 patent drawingFigure 3

AI summary

Fluid detection systems and methods using the same are disclosed. In embodiments the fluid detection systems include a sensor module and an electronics module. The sensor module includes a sensor housing that includes a liquid flow path and a sensor element disposed around at least part of the liquid flow path. The sensor element can detect a capacitance of the liquid flow path and provide a sensor signal to a controller in the electronics module. The electronics module can determine a detected capacitance in the liquid flow path based at least in part on the sensor signal, and can determine whether a wet event has occurred based on a comparison of the detected capacitance to a threshold capacitance. Methods using the fluid detection systems and fluid supply systems including the fluid detection systems are also disclosed.