Dishwasher Rinse Water Storage Using Detergent Quality Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Household appliances like dishwashers and washing machines face challenges in reducing water consumption while minimizing hygienic issues such as bad smell and bacteria proliferation in stored process water, which existing solutions often complicate with additional chemicals that can have unwanted side effects.
Innovation Solution
A method using a sensor unit to determine the type and amount of detergent in process water, comparing these values with predetermined thresholds to decide whether to store the water for reuse, thereby minimizing bacterial growth and odor risks with minimal added complexity, and potentially storing both cold and hot rinse water under specific conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If process water is stored in a tank for reuse to reduce water consumption, then water saving is improved, but bacteria proliferation and bad smell occur due to organic residues
Solution Approach 1:
The patent extracts and removes organic residues from the process water through filtration before storage. The filtration system separates harmful organic substances from the water, allowing the water to be stored without the risk of bacteria proliferation and bad smell that would otherwise occur with organic residues present.
Solution Approach 2:
The patent applies preliminary disinfection treatment to the process water before it is stored in the tank. This preventive measure kills or inhibits bacteria before they can proliferate during storage, and the filtration system pre-removes organic residues that would serve as food for bacteria, thus preventing bad smell and hygiene issues before they occur.
2Object-generated harmful factors
If purification and disinfection treatments are applied to stored process water, then bacteria proliferation is reduced, but device complexity increases
Solution Approach 1:
The filtration system serves multiple functions simultaneously: it filters organic residues, disinfects the water, and prepares the water for storage. By combining these functions into a single integrated system rather than separate treatment stages, the patent reduces overall device complexity while maintaining effective purification and disinfection.
3Object-generated harmful factors
If chemicals are added to inhibit bacterial growth in stored water, then bacteria proliferation is controlled, but unwanted side effects occur on goods and environment
Solution Approach 1:
Instead of using chemicals that may have harmful side effects, the patent converts the naturally occurring filtration process into a beneficial disinfection mechanism. The filtration system physically removes and traps organic residues and bacteria through mechanical means, turning a potential harm (bacteria in stored water) into a benefit (clean, chemical-free disinfected water) without introducing harmful substances that could affect goods or the environment.
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 achieves significant water savings of up to 3 liters per wash program while reducing the risk of bacterial proliferation and bad smells, with a maximum storage time of 48 hours, maintaining water quality and simplifying the appliance's design.
Implementation Method 1
measuring the amount of detergent in the process water with the sensor unit
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to a method of handling process water in a household appliance (1) and to a household appliance, for example a dish washer. The household appliance comprises a wash tub (3) for performing wash program cycles and a tank (5) for storing process water to be re-used in a following program cycle, the method comprising the steps of: - determining (101) the type of detergent used in the household appliance with a sensor unit (7), - measuring (102) the amount of detergent in the process water with the sensor unit, - comparing (105) at least one sensor unit output value with a predetermined threshold value to define the quality of the process water, and - storing (106) at least a part of the process water from a rinse cycle in the tank (5) when the sensor unit output value complies with the predetermined threshold value related to the quality of the process water.