Device and method for determining the dirt load in a rinsing or detergent solution

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Solution Overview

Problem

Current technologies in water-bearing household appliances, such as dishwashers, inadequately characterize the dirt load in washing or rinsing liquor, particularly failing to distinguish between relevant dirt components like fat, starch, and protein, which requires specific cleaning agents, leading to suboptimal cleaning results.

Innovation Solution

A device using near-infrared (NIR) spectroscopy to detect spectral measurements of dirt components in the washing liquor, allowing for the determination of the type and quantity of soiling, and adjusting washing parameters based on these measurements to optimize the cleaning process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical sensors are used to measure turbidity of the rinsing or washing liquor, then the quantity and kinetics of the dirt load can be detected, but the sensors cannot distinguish between different dirt components (fat, starch, protein) that require different cleaning agents

Engineering Contradiction:
Improvedirt load detectionVSAvoiddirt component characterization
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the measurement process by using multiple sensors with different measurement principles (optical turbidity sensor, electrical conductivity sensor, and potentially other sensors) to measure different aspects of the washing liquor separately. Each sensor provides specific information about different components, and the control unit integrates these segmented measurements to achieve complete dirt load characterization without losing information about specific dirt components.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If conventional optical sensors measure only overall turbidity, then the measurement system remains simple, but the cleaning result is suboptimal because different dirt components requiring different cleaning agents cannot be distinguished

Engineering Contradiction:
Improvesensor systemVSAvoidcleaning result
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent merges multiple sensing functions into a single integrated sensor system. The optical sensor for turbidity measurement and the electrical conductivity sensor are combined and controlled by a single control unit that processes signals from both sensors. This merging allows the system to maintain relatively simple device architecture while achieving reliable cleaning results through comprehensive measurement of both overall turbidity and specific dirt component indicators.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit serves multiple functions: it processes signals from the optical turbidity sensor, processes signals from the electrical conductivity sensor, determines the dirt load based on both measurements, and controls the dosing device. This multi-functionality allows a single control unit to manage the entire measurement and dosing process, achieving reliable cleaning results without significantly increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If the sensor system cannot differentiate between dirt load and other factors influencing turbidity (detergents, precipitation), then the system remains simple to operate, but the dirt load characterization is inaccurate

Engineering Contradiction:
Improvesystem operationVSAvoiddirt load characterization
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring both optical turbidity and electrical conductivity, then using this feedback information to determine the actual dirt load. The control unit processes the feedback signals from both sensors and adjusts the dirt load determination accordingly, compensating for interfering factors like detergent presence and precipitation. This feedback mechanism maintains ease of operation while significantly improving measurement precision.

Inventive Principle:
Principle #23Feedback

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 precise detection and management of dirt components, leading to improved cleaning efficiency and resource conservation by optimizing washing programs based on the identified soiling levels.

Implementation Method 1

A device using near-infrared (NIR) spectroscopy to detect spectral measurements of dirt components in the washing liquor

Methodology Applied
Scientific EffectNear-infrared spectroscopy: Absorption Spectroscopy

Data Source

PatentEP3302210B1Device and method for determining the dirt load in a rinsing or detergent solution
Publication Date: 2020.07.08 BSH HAUSGERATE GMBH
  • EP3302210B1 patent drawingFigure 1~2
  • EP3302210B1 patent drawingFigure 3
  • EP3302210B1 patent drawingFigure 4

AI summary

A device (12, 13, 14, 15) and a method for determining the composition of the dirt load in a rinsing or detergent solution in a water-using household appliance (1), for example in a dishwasher (1), using near infrared spectroscopy (NIR). Furthermore, a cleaning agent form, for example a cartridge, in which the different cleaning agent preparations can be provided separately from each other, for example in separate accommodation chambers, is disclosed in combination with the methods described herein.