Fiber Concentration Profile Measuring Apparatus Using Series Resonance Circuits

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Solution Overview

Problem

Current fiber concentration profile measuring apparatuses in pulp production are bulky, complex, and inefficient, with temperature data not accurately indicating refiner pad consistency, leading to suboptimal energy usage and pulp quality in papermaking industries.

Innovation Solution

A fiber concentration profile measuring apparatus using conductor bodies with electric contact surfaces and series resonance circuits to measure electrical resistivity and conductivity of the fiber pad material, allowing for precise determination of fiber concentration profiles through impedance measurements with a controlled AC current, reducing the number of lead wires and simplifying maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensors and complex software applications are used for fiber concentration measurement, then measurement capability is provided, but device complexity and cost increase significantly

Engineering Contradiction:
Improvefiber concentration measurementVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex temperature-based measurement systems with a simple electrical resistance measurement system. Instead of using temperature sensors, pressure sensors, flow meters, and complex software algorithms, the invention uses conductor bodies that measure electrical resistance of the fiber pad material directly, providing a much simpler system with comparable or better measurement accuracy.

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

Solution Approach 2:

The invention extracts only the essential measurement function needed for fiber concentration detection. By removing unnecessary temperature sensors, pressure sensors, flow meters, and complex software applications, the system retains only the critical electrical resistance measurement capability, thereby simplifying the overall system while maintaining measurement effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If multiple lead wires are used for each conductor body, then individual measurement is enabled, but ease of operation and maintenance deteriorate

Engineering Contradiction:
Improveindividual conductor body measurementVSAvoidhandling during service and maintenance
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent merges the electrical connection functions of multiple lead wires into a single common electrical connection. All conductor bodies share a common electrical path back to the control unit, eliminating the need for separate lead wires for each conductor body. This reduces wiring complexity and significantly improves ease of installation, operation, and maintenance.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If temperature data is used for fiber concentration estimation, then measurement is possible, but measurement accuracy deteriorates because temperature does not directly indicate fiber concentration

Engineering Contradiction:
Improvefiber concentration indicationVSAvoidmeasurement accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent substitutes indirect temperature-based estimation with direct electrical resistance measurement. Electrical resistance of the fiber pad material directly correlates with fiber concentration, providing a reliable and accurate measurement method that eliminates the indirect and less accurate temperature-based estimation approach.

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 accurate, cost-effective, and energy-efficient fiber concentration profile measurements, enhancing pulp quality and reducing energy consumption by stabilizing the primary electric current and using a fixed frequency, thereby improving the handling and performance of the measuring apparatus.

Implementation Method 1

The actual electrical resistivity and/or electrical conductance of the fiber pad material will determine the electrical resistance, which being measured by each conductor body one at a time

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The conductor bodies are connected in series with a respective series resonance circuit being individually adapted to give free passage for the electric current to a certain frequency

Methodology Applied
Scientific EffectSeries resonance: Resonance

Data Source

PatentEP3877757B1A fiber concentration profile measuring apparatus
Publication Date: 2023.07.26 DAPROKS AB
  • EP3877757B1 patent drawingFigure 1~3
  • EP3877757B1 patent drawingFigure 4
  • EP3877757B1 patent drawingFigure 5

AI summary

The present invention concerns a fiber concentration profile measuring apparatus (1) comprising a plurality of conductor bodies (9, 509), configured to be coupled to a primary AC power source (17) comprising an impedance measuring unit (18), the respective conductor body (9, 509) exhibits a first electric contact surface (10) configured to transfer a primary electric current (PEC) from the primary AC power source (17) to a second electric contact surface (12) via a fiber pad material being pulped. Each conductor body (9, 509) is coupled in series with a respective electronic switching device (49', 49'', 49''', 49'''', 49'''''), each of which is configured to switch between on-and off-state for feeding or not feeding the primary electric current (PEC) to the associated conductor body (9, 509); and a secondary power source (21), configured to generate a secondary electric current injected with a range of frequencies, is coupled to each electronic switching device (49', 49'', 49''', 49'''', 49''''') via a respective series resonance circuit (SRC', SRC'', SRC''', SRC'''', SRC''''') being individually adapted to give free passage for the secondary electric current at a certain frequency providing said on-state.