Optical Off-Gas Velocity Sensor for Furnace Ducts

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Solution Overview

Problem

Existing systems for analyzing combustion off-gases in industrial furnaces, such as those in steelmaking operations, lack real-time measurement capabilities for off-gas flow velocities and volumes, which are crucial for optimizing furnace operations and reducing emissions.

Innovation Solution

An apparatus with paired coherent light emitters and sensors is used to measure the velocity and volume of off-gas flows in real-time by detecting the absorption signature of specific gas species, allowing for the calculation of flow velocities and volumes, and adjusting furnace parameters accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing gas analysis systems are used, then off-gas constituent analysis is possible, but real-time flow velocity and volume measurement is not achievable

Engineering Contradiction:

Improveoff-gas flow velocity measurementVSAvoidreal-time measurement capability

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces mechanical flow measurement systems with an optical measurement system. Coherent light beams are emitted through the off-gas flow, and the absorption characteristics of the light by gas species are measured to determine flow velocity and volume in real-time, eliminating the need for mechanical sensors in the gas stream.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses coherent light beams as an intermediary to measure off-gas flow properties. The light interacts with the gas species in the off-gas stream, and by measuring the absorption of light at different locations, the system indirectly determines flow velocity and volume without directly contacting or obstructing the gas flow.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If light beam propagation method is used for gas analysis, then constituent identification is possible, but flow velocity measurement capability is insufficient

Engineering Contradiction:

Improveflow velocity measurement capabilityVSAvoidflow velocity and volume data

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent makes the optical measurement system multi-functional by enabling it to simultaneously perform constituent identification and flow velocity measurement. The same coherent light beam propagation method used for identifying gas species is extended to measure flow velocity and volume by analyzing light absorption at multiple locations and calculating time differences.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent adds the dimension of temporal measurement to the spatial optical measurement. By measuring light absorption at multiple locations along the flow path and calculating the time difference for the light to traverse these locations, the system derives flow velocity information from the spatial-optical measurements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If real-time off-gas measurement is implemented, then furnace operation optimization is enabled, but system complexity increases

Engineering Contradiction:

Improvefurnace operation efficiencyVSAvoidmeasurement system structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent simplifies the overall system architecture by replacing complex mechanical flow measurement devices with a relatively simple optical system consisting of light sources, detectors, and signal processing units. This substitution reduces mechanical complexity while enabling real-time measurements that improve furnace operation efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This solution enables real-time optimization of furnace operations, reduces undesired emissions, and prevents overloading of downstream scrubbers by providing accurate data on off-gas flow properties, leading to improved efficiency and control of combustion processes.

Implementation Method 1

measuring the amount of light energy which is absorbed by a particular off-gas species component

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

the time between the identification of the gas absorption signature at the first and second positions provide an output signal based on an identified velocity

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Data Source

PatentUS11921036B2In situ apparatus for furnace off-gas constituent and flow velocity measurement

Publication Date: 2024.03.05 TENOVA GOODFELLOW INC

AI summary

An optically based combustion off-gas stream velocity sensor assembly is provided for detecting in real-time off-gas flow velocity and/or volume as it moves through a flue duct. The sensor assembly includes two paired coherent light emitters and optic sensors, positioned in a spaced orientation in the flow path direction. The light emitter/optic sensor pairs operate to emit and detect across the off-gas stream coherent light beam energy having a wavelength component corresponding to an absorption profile of an off-gas species component. The detection of non-absorbed portions of the emitted beam is used to identify and detect the movement of a flow species signature at different locations along the flue duct.