Capacitive Fire Suppression Level Sensor

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Solution Overview

Problem

Current methods for determining the level of clean agent in fire suppression cylinders are tedious and limited to welded cylinders, lacking accuracy and efficiency, especially for seamless cylinders.

Innovation Solution

A fire suppression system utilizing a processor to determine the amount of suppressant based on capacitance between electrodes, with a siphon tube and cylinder wall acting as electrodes, and a pressurant as a dielectric medium, allowing for real-time monitoring and suitable for both seamless and welded cylinders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If magnetic float and reed switch based techniques are used to determine clean agent level, then the measurement can be performed, but the process is tedious and limited to welded cylinders only

Engineering Contradiction:
Improvecylinder type compatibilityVSAvoidmeasurement process simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent replaces mechanical float and reed switch mechanisms with a capacitive sensing system that uses electrical fields to detect suppressant levels. This substitution eliminates the need for mechanical components that require specific cylinder configurations, enabling the system to work with both welded and seamless cylinders equally effectively.

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

Solution Approach 2:

The capacitive sensing system is designed to be universally applicable to different cylinder types (welded and seamless) by using electrical field interactions rather than mechanical interactions. The system performs level detection across multiple cylinder configurations without requiring type-specific adjustments or components.

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

2Measurement precision

If traditional level determination methods are used, then suppressant level can be detected, but the process is tedious and time-consuming

Engineering Contradiction:
Improvesuppressant level detection accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces tedious mechanical measurement processes with automated capacitive sensing that provides rapid, continuous level monitoring. The electrical field-based measurement occurs instantaneously without manual intervention, significantly reducing measurement time while maintaining or improving detection accuracy through precise capacitance measurements.

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

Solution Approach 2:

The system enables continuous monitoring of suppressant levels through constant capacitive sensing, eliminating the need for periodic manual measurements. This continuous action provides real-time level information without time loss, allowing the system to continuously track suppressant levels and provide immediate alerts when thresholds are reached.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If capacitance measurement between siphon tube and wall is used, then real-time monitoring is achieved, but the system complexity increases

Engineering Contradiction:
Improvemonitoring efficiencyVSAvoidsensor system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system uses the existing structural components (siphon tube and cylinder wall) as capacitive sensors, giving these components a dual function: their original mechanical function plus electrical sensing function. This approach enables real-time monitoring without adding separate dedicated sensor components, thereby maintaining system simplicity while achieving continuous monitoring capability.

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

Solution Approach 2:

The system utilizes the inherent electrical properties of existing structural components (siphon tube and wall) to perform sensing functions. These components essentially 'self-serve' as capacitive sensors, eliminating the need for additional dedicated sensing components and reducing overall system complexity while enabling real-time monitoring.

Inventive Principle:
Principle #25Self-service

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

Provides accurate, real-time monitoring of suppressant levels with improved sensor life and ease of retrofitting, suitable for seamless cylinders, and offers reliable and linear sensing capabilities.

Implementation Method 1

a capacitance sensor operable to measure a capacitance between the siphon tube and the cylinder wall

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

the capacitance being an effective capacitance based on a first capacitance between the siphon tube and the wall with the suppressant as a dielectric medium, a second capacitance between the siphon tube and the wall with the pressurant as a dielectric medium

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP3702662B1Fire suppressant system
Publication Date: 2022.09.14 CARRIER CORP
  • EP3702662B1 patent drawingFigure 1
  • EP3702662B1 patent drawingFigure 2
  • EP3702662B1 patent drawingFigure 3

AI summary

An example fire suppression system 10 includes a cylinder 12 having a wall 22 defining an inner chamber 24, and a processor 18 operable to determine an amount of a suppressant 36 in the inner chamber 24 based on a capacitance between a first electrode and a second electrode that are both in contact with the suppressant 36. An example method for determining an amount of suppressant 36 in the cylinder 12 includes measuring a capacitance between a first electrode and a second electrode that are both in contact with the suppressant 36 within the cylinder 12, and determining an amount of suppressant 36 within the cylinder 12 based on the capacitance.