Electromagnetic Sensor for Filter Press Cake Moisture Detection

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Solution Overview

Problem

Filter press operations for solid-liquid separation require extensive operator experience to manage moisture content and cake composition, leading to inefficiencies and operational disturbances, as existing systems lack reliable, experience-independent methods for monitoring and controlling these parameters.

Innovation Solution

Integration of an electromagnetically operating sensor with spaced-apart conductor electrodes in the press wall of a filter press, which measures the dielectric constant of filter cakes to determine water content and conductivity values, allowing for real-time monitoring and optimization of process parameters without the need for reference measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If operator experience is used to manage moisture content and cake composition, then operational judgment can be made, but inefficiencies and operational disturbances occur due to lack of reliable monitoring

Engineering Contradiction:
Improveoperational reliabilityVSAvoidfiltering efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces manual operator experience and judgment with an electromagnetic sensing system that automatically measures moisture content and conductivity in filter cakes. The sensor system substitutes human expertise with objective, real-time measurements, eliminating the unreliability of experience-based operations while maintaining continuous productivity.

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

Solution Approach 2:

The patent implements a feedback mechanism where electromagnetic sensors continuously measure moisture content and conductivity parameters, and this information is used to automatically control the filtering process. The feedback loop enables real-time adjustments without operator intervention, resolving the contradiction between reliability and productivity.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If extensive operator experience is required to check moisture values during operation, then process control is possible, but operational complexity and time consumption increase

Engineering Contradiction:
Improveoperational simplicityVSAvoidtime for moisture checking
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent enables the filter press system to self-monitor and self-control the filtering process through integrated electromagnetic sensors. The system automatically checks moisture values and conductivity parameters without requiring operator intervention, making the operation simpler and eliminating time loss associated with manual checking.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Manual moisture checking operations are replaced by automated electromagnetic sensing. The sensor system performs measurements continuously and automatically, eliminating the time-consuming manual inspection process while simplifying operational procedures.

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

3Productivity

If filter press is switched off to discharge filter cake, then complete cake removal is achieved, but productivity is reduced due to operational interruptions

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidprocess control accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent enables continuous monitoring and control of the filtering process through electromagnetic sensors that operate without interruption. Moisture content and conductivity measurements continue throughout the filtering cycle, allowing the process to run continuously without shutdowns while maintaining accurate process control.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The feedback system provides continuous information about filter cake moisture and conductivity, enabling real-time process optimization. This allows the filter press to maintain reliable process control while operating continuously, eliminating the need to switch off for cake discharge.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If electromagnetically operating sensor with two spaced-apart conductor electrodes is used to measure dielectric constant, then moisture content determination is achieved, but device complexity increases

Engineering Contradiction:
Improvemoisture measurement accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses the dielectric constant as an intermediary parameter to indirectly measure moisture content. Instead of directly measuring moisture, the electromagnetic sensor measures the dielectric constant of the filter cake, which correlates with moisture content. This intermediary approach provides accurate moisture determination while using a relatively simple electromagnetic sensing mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables efficient, experience-independent operation of filter presses by reliably detecting moisture and conductivity values, optimizing process parameters, and reducing operational disruptions, particularly in filtering suspensions with flocculated salts.

Implementation Method 1

the sensor measuring the dielectric constant of the press wall on both sides of each The filter cake formed by the filter element is determined

Methodology Applied
Scientific EffectDielectric constant measurement: Dielectric Permittivity

Data Source

PatentEP3359274B1Filter press, use of an electromagnetically operating sensor in the same and filtering element in plate form
Publication Date: 2022.04.06 IMKO MICROMODULTECHN
  • EP3359274B1 patent drawingFigure 1
  • EP3359274B1 patent drawingFigure 2
  • EP3359274B1 patent drawingFigure 3a

AI summary

The invention is concerned with a filter press for the solid-liquid separation of suspensions comprising a number of filtering elements in plate form arranged one behind the other and clamped together at the edges, with a press wall, a plate frame and a filtering means (23), such as a woven fabric or membrane. The filter press also has a suspension inlet and a filtrate outlet. In every two adjacent and neighbouring filtering elements there are cake chambers, in which the filter cake builds up when the filter press is in the operating state. Arranged in the press wall (21) of a filtering element (2; 20; 30) is an electromagnetically operating sensor (18), which for determining the dielectric constant of the filter cakes (9) formed on both sides of the press wall (21) has two spaced-apart conductor electrodes (18a), which are kept at a distance from the cake chamber (8) by the press wall. This sensor determines the dielectric constant of the filter cakes formed on both sides of the press wall of the filtering element and, by means of an evaluation device, determines from this a water content value and/or a conductivity value.