Water Softener Regeneration Control Without Conductivity Sensors

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Solution Overview

Problem

Water softening systems face inefficiencies due to the slow dissolution of solid regenerating salt, leading to variable concentrations of regenerating agent solutions, which can result in incorrect salt usage, incomplete regeneration, and corrosion issues with conductivity sensors.

Innovation Solution

A method that measures the volume or mass of regenerating agent solution conveyed and the time taken during regeneration, using a calibration function to determine the concentration based on the relationship between the injector's delivery capacity and the density ratio of the regenerating agent to motive water, eliminating the need for corrosive conductivity sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conductivity sensor is used to determine the concentration of regenerating agent solution, then the concentration can be measured, but the sensor is subject to considerable corrosion and has to be replaced regularly

Engineering Contradiction:
Improveconcentration measurementVSAvoidsensor durability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts the measurement function from the corrosive environment by using a flow meter to measure motive water volume flow instead of placing a conductivity sensor in the regenerating agent solution. This removes the sensor from the harmful corrosive medium while still enabling concentration determination through indirect measurement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces motive water volume flow as an intermediary parameter to indirectly determine the concentration of regenerating agent solution. Instead of directly measuring concentration with a sensor in the corrosive solution, the system measures the volume of motive water required to deliver a fixed mass of salt, which correlates to concentration without exposing any sensor to the corrosive environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the dissolution time of solid regenerating salt is extended to ensure saturation, then the concentration becomes more consistent, but the regeneration process takes longer

Engineering Contradiction:
Improvesolution concentration consistencyVSAvoidregeneration time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The patent implements feedback control by measuring the actual motive water volume flow and using it to calculate the concentration of regenerating agent solution. This feedback mechanism allows the system to monitor and adjust the regeneration process in real-time, ensuring consistent salt delivery without requiring extended dissolution times for saturation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces the chemical-based saturation approach (waiting for complete dissolution) with a mechanical measurement approach (flow meter measurement). By measuring the volume of motive water required to transport a fixed mass of salt, the system determines concentration without relying on the salt being fully dissolved, thus reducing the required dissolution time.

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

3Productivity

If the concentration of regenerating agent solution is increased to improve regeneration efficiency, then less salt is needed, but the dissolution process becomes even slower

Engineering Contradiction:
Improveregeneration efficiencyVSAvoidsalt dissolution speed
Core Design Contradiction:
ProductivityVSSpeed

Solution Approach 1:

The patent replaces reliance on dissolution speed with direct mechanical measurement of motive water volume flow. This allows the system to accurately determine concentration and control salt delivery regardless of how fast the salt dissolves, enabling the use of higher concentrations without waiting for complete dissolution.

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

Solution Approach 2:

The patent changes the measurement parameter from direct concentration measurement (which requires saturated solutions) to motive water volume flow measurement. This parameter change allows the system to work with unsaturated solutions of varying concentrations without compromising measurement accuracy, thus improving dissolution speed while maintaining regeneration efficiency.

Inventive Principle:
Principle #35Parameter changes

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 method ensures accurate tracking of salt consumption, optimizes salt utilization, prevents incomplete regeneration, and reduces maintenance costs by avoiding sensor corrosion, ensuring reliable and efficient water softening operations.

Implementation Method 1

a motive water volume flow of raw water is fed to the injector from an inlet and this motive water volume flow entrains regenerating agent solution via a line

Methodology Applied
Scientific EffectEntrainment: Entrainment

Implementation Method 2

the electronic control device with a stored calibration function, in particular comprising one or more stored calibration characteristics, a concentration C RM1 of the pumped regenerating agent solution and/or one that depends on the concentration of the pumped regenerating agent solution Size, in particular an amount of salt SM1 contained in the pumped regenerating agent solution, is determined from V1 or M1 and/or from t1, the calibration function exploiting the relationship between the delivery capacity of the injector and the density ratio of regenerating agent solution to motive water

Methodology Applied
Scientific EffectDensity ratio relationship: Density Gradient

Data Source

PatentEP3524577B1Water softening method with determination of regenerant concentration via pump duration and pump volume or a mass to be transported
Publication Date: 2021.03.10 JUDO WASSERAUFBEREITUNG
  • EP3524577B1 patent drawingFigure 1
  • EP3524577B1 patent drawingFigure 2
  • EP3524577B1 patent drawingFigure 3

AI summary

A water softening system (1), comprising: - a softening device (4a), in particular comprising at least one container (4) with ion exchange resin (5), - a storage vessel (6) in which a regeneration solution (24) is stored, in particular wherein the storage vessel (6) also contains solid regeneration salt (7), - an injector (8) for transporting regeneration solution (24) from the storage vessel (6) to the softening device (4a), - an electronic control device (9) configured to control the pumping of the regeneration solution (24) from the storage vessel (6) to the softening device (4a) during regeneration operation, is characterized in that the water softening system (1) is configured to specify or measure a volume V1 or a mass M1 of pumped regeneration solution (24) in a pumping step (106).- and specify or measure a time duration t1 for the delivery of the volume V1 or the mass M1 (108), and that the electronic control device (9) is configured to determine, with a stored calibration function, in particular comprising one or more stored calibration curves, a concentration CRM1 of the delivered regeneration solution (24) and/or a quantity dependent on the concentration of the delivered regeneration solution (24), in particular a quantity of salt SM1 contained in the delivered regeneration solution (24), from V1 or M1 and/or from t1 (116, 118; 140). With the water softening system according to the invention, the salt usage during the regeneration of the softening device can be checked simply and reliably. (Fig. 1),