External Duct Flow Sensing for Reliable Extraction Power Control

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Solution Overview

Problem

Current fluid flow measuring devices for processing machines, particularly in the furniture and construction industry, face challenges in ensuring high reliability, productivity, and energy efficiency while managing fine dust and noise pollution, often leading to increased machine downtimes and reduced economic efficiency due to clogged sensors and inefficient energy use.

Innovation Solution

A fluid flow measuring device with a sensor unit arranged outside the housing, featuring multiple measuring points and a differential pressure sensor, vane wheel sensor, or ultrasonic sensor, which detects the gaseous fluid flow and includes a particle detection device to assess suction performance, allowing for decentralized control and regulation of the suction power based on real-time flow and contamination data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optical sensors are used to monitor particle load in the extraction duct, then extraction power can be controlled according to particle load, but the sensors become clogged with deposited particles leading to unreliable signals and increased machine downtimes

Engineering Contradiction:
Improvereliability of extraction power controlVSAvoidmachine downtime
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The sensor unit is extracted from the particle-laden fluid flow environment and positioned in a protected location outside the extraction duct. This allows the sensor to detect flow conditions without being exposed to particles that would cause clogging, thereby maintaining reliable operation and avoiding machine downtime.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary measurement approach where instead of directly measuring particle load with sensors in the duct, the system measures fluid flow characteristics (velocity, pressure) as indirect indicators of extraction performance. This intermediary measurement method avoids direct particle-sensor contact while still providing control information.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If extraction system runs continuously to ensure sufficient extraction capacity, then particulate matter limits are met, but energy consumption increases

Engineering Contradiction:
Improveparticulate matter emissionsVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The system implements feedback control by continuously monitoring fluid flow characteristics and using this information to dynamically adjust extraction power. The sensor unit provides real-time data on flow velocity or pressure, which feeds back to the control system to optimize extraction capacity and minimize energy consumption while maintaining compliance with particulate matter limits.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The extraction system transitions from static continuous operation to dynamic variable-speed operation. The extraction power is adjusted in real-time based on measured flow conditions, allowing the system to operate at optimal power levels rather than running at constant high capacity, thereby reducing energy consumption while maintaining effectiveness.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If extraction power is controlled according to particle load, then energy consumption is reduced, but complex measuring devices are required that are prone to clogging

Engineering Contradiction:
Improveenergy consumptionVSAvoidcomplexity of measuring device
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent replaces complex optical or particle-detection measuring systems with simpler mechanical or fluid-dynamic sensors that measure flow velocity or pressure. These simpler sensors have no moving parts that can be clogged by particles and provide sufficient information for extraction power control, thereby reducing both device complexity and susceptibility to particle interference.

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 provides a reliable and efficient assessment of fluid flow, ensuring high productivity and energy efficiency by accurately monitoring suction performance and adjusting suction power, thereby reducing machine downtimes and energy consumption while maintaining environmental compliance.

Implementation Method 1

the sensor unit is a differential pressure sensor

Methodology Applied
Scientific EffectDifferential pressure sensing: Pressure Drop

Implementation Method 2

a sensor arranged outside the pipe section through which a flow flows for detecting vibrations in the region of the pipe section

Methodology Applied
Scientific EffectFlow-induced vibrations: Vibration

Implementation Method 3

a vortex sensor (eddy current meter)

Methodology Applied
Scientific EffectVortex/eddy current generation: Eddy Currents

Implementation Method 4

a thermal sensor (hot-wire anemometer)

Methodology Applied
Scientific EffectHeat transfer: Convection

Implementation Method 5

an ultrasonic sensor

Methodology Applied
Scientific EffectUltrasonic wave propagation: Ultrasound

Data Source

PatentEP3851809B1Fluid flow measuring device, processing machine with fluid flow measuring device, control and / or regulating device and method
Publication Date: 2024.10.23 HOMAG GMBH
  • EP3851809B1 patent drawingFigure 1~2
  • EP3851809B1 patent drawingFigure 3
  • EP3851809B1 patent drawingFigure 4

AI summary

The present invention relates to a fluid flow measuring device 1 for evaluating a gaseous fluid flow of a machine tool 10 for machining preferably plate-shaped workpieces, which in particular consist at least partially of wood, wood-based materials, wood substitutes, plastic(s), composite material(s) or the like, comprising: at least one flow-through, preferably annular housing 20 for guiding a gaseous fluid flow 30, which is configured to be implemented in a flow-guiding duct, in particular in the extraction duct and/or blow-air duct, of the machine tool, at least one measuring point M1, M2, which is provided on the flow-through housing 20 and a sensor unit 40 preferably arranged outside the flow-through housing 20 for detecting the gaseous fluid flow 30 by means of the at least one measuring point M1, M2, wherein the sensor unit 40 comprises a differential pressure sensor, a vane sensor,a vortex sensor, a thermal sensor, an ultrasonic sensor, two pressure sensors, or the like. Furthermore, the present invention describes a machine tool 10 equipped with the fluid flow measuring device 1 according to the invention, a control and/or regulating device 90, and a method for evaluating and/or monitoring a gaseous fluid flow of a machine tool.