Electrodeionization Resin Expansion Sensor Feedback Control

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Solution Overview

Problem

Existing electrodeionization (EDI) devices face challenges in reliably controlling electric current to maintain optimal ion-exchange resin regeneration and prevent mechanical stress, leading to inefficient energy consumption and potential leaks, especially due to changes in feed water characteristics and flow rates over time.

Innovation Solution

Incorporating sensors to measure dimensional changes and mechanical stress within the ion-exchange material-filled compartments, allowing for real-time adjustment of electric current to optimize resin regeneration and prevent excessive expansion or shrinkage, thereby ensuring consistent water quality and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electric current is increased to maintain resin regeneration, then the regeneration degree of ion-exchange material is improved, but the mechanical stress on compartment walls increases causing deformation and potential leaks

Engineering Contradiction:
Improveresin regeneration degreeVSAvoidmechanical stress on compartment walls
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent employs a feedback control system where dimensional changes of the ion-exchange material are continuously measured by sensors and used to adjust the electric current in real-time. This closed-loop control maintains resin regeneration at optimal levels while preventing excessive expansion that would cause mechanical stress and compartment deformation, thus resolving the contradiction between regeneration effectiveness and structural integrity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the electric current parameter based on measured dimensional changes of the resin bed. By changing the current parameter in response to resin expansion/shrinkage, the system optimizes regeneration while preventing mechanical stress, effectively managing the trade-off between chemical effectiveness and mechanical safety.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the electric current is maintained at a high level to ensure complete resin regeneration, then the water quality is improved, but the energy consumption increases excessively

Engineering Contradiction:
Improvewater qualityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The feedback control system continuously monitors resin dimensional changes and adjusts electric current accordingly. This real-time adjustment ensures that current is increased only when resin expansion indicates incomplete regeneration, and reduced when optimal regeneration is achieved, thereby maintaining high water quality while minimizing unnecessary energy consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of maintaining a constantly high electric current, the system applies partial action by adjusting current levels based on actual resin state. This approach uses only the necessary amount of energy required for complete regeneration at any given time, avoiding excessive energy consumption while ensuring water quality standards are met.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If the electric current is reduced to lower energy consumption, then the energy efficiency is improved, but the resin regeneration becomes insufficient leading to poor water quality

Engineering Contradiction:
Improveenergy efficiencyVSAvoidwater quality
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The feedback mechanism ensures that electric current is reduced only when sensor measurements confirm that resin dimensional changes indicate complete regeneration. This intelligent reduction maintains water quality by ensuring regeneration is complete before lowering current, thus improving energy efficiency without compromising water quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system uses the resin's own dimensional changes as a self-indicating signal for regeneration status. The resin effectively monitors its own state through expansion/shrinkage, and this self-information is used to control current adjustment, eliminating the need for external water quality analysis while ensuring quality standards are met before reducing energy input.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If sensors and control systems are added to monitor resin dimensional changes, then the control precision of electric current is improved, but the device complexity increases

Engineering Contradiction:
Improvecontrol precision of electric currentVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex chemical analysis systems with a simpler mechanical/dimensional measurement approach. By measuring physical dimensional changes of the resin bed instead of analyzing water chemistry or resin chemical composition, the system achieves precise control of electric current with simpler, more reliable sensors, thus improving control precision while minimizing the increase in device complexity.

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 approach enables efficient and cost-effective control of electric current, maintaining high water quality while preventing mechanical damage and optimizing energy use, even with varying feed water conditions and flow rates.

Implementation Method 1

the increase of regeneration degree of ion-exchange material results in an expansion of the resin and a mechanical stress on the walls of the compartment

Methodology Applied
Scientific EffectIon-exchange material expansion:

Data Source

PatentEP2402290B1Electrodeionization device and method comprising control of the electric current by measurement of ion-exchange material expansion
Publication Date: 2016.01.06 EMD MILLIPORE CORP
  • EP2402290B1 patent drawingFigure 1~2
  • EP2402290B1 patent drawingFigure 3~5
  • EP2402290B1 patent drawingFigure 6

AI summary

Device (2) for the removal of ions from a polar liquid (F), e.g. water, comprising at least one compartment (14') which comprises at least one inlet for an entering polar liquid flow and at least one outlet for an outgoing deionized liquid flow (D), in which said compartment (14') an electrochemically regenerable ion-exchange material fills a zone through which zone a liquid flow is able to pass, the device (2) being characterized in that it comprises one sensor (1) of at least one dimensional change of the ion-exchange material. The sensor can comprise a photo-sensor or a sensor of mechanical stress. Preferably an apparatus (100, 10, 11) connected to the sensor is able to analyze this dimensional change and to control the electric current. Method of using said device (2), whereby the electrical current applied to the device (2) is controlled according to the expansion of the resin.