Dishwasher Screen Blockage Detection Using Optical Turbidity Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dishwashers face operational reliability issues due to blockages in the screen arrangement, which can lead to incomplete washing and incorrect detection of blockages, resulting in unsatisfactory wash results and potential malfunctions.
Innovation Solution
Incorporating a control facility with an optical turbidity sensor to detect blockages by measuring the degree of transmission in the circulation chamber before and after evacuating wash fluid, and evaluating changes to determine if the screen arrangement is blocked, allowing for automatic countermeasures and improved detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the screen arrangement is used to filter wash fluid, then wash fluid quality is improved, but blockage of the screen arrangement occurs leading to operational reliability deterioration
Solution Approach 1:
The detection sequence is performed before the wash cycle completes, measuring the degree of transmission at an initial state and after evacuation. This preliminary detection allows the system to identify blockages before they cause operational failures, enabling preventive action while the dishwasher is still functional.
Solution Approach 2:
The control facility continuously monitors the degree of transmission through the screen arrangement using optical turbidity sensors. This feedback mechanism allows the system to detect changes in screen permeability and trigger appropriate responses, such as alerting the user or initiating cleaning cycles, thereby maintaining operational reliability.
2Reliability
If the screen arrangement blocks wash fluid flow, then filtration is improved, but wash cycle completion is prevented causing productivity loss
Solution Approach 1:
The system performs detection sequences at predetermined points during the wash cycle to identify blockages before they prevent cycle completion. By measuring transmission degrees at different stages, the system can detect emerging blockages and trigger preventive measures while the wash cycle is still ongoing.
Solution Approach 2:
The control facility uses real-time transmission measurements to monitor screen arrangement status throughout the wash cycle. This continuous feedback enables the system to distinguish between normal flow variations and actual blockages, ensuring that productive wash cycles continue uninterrupted while identifying genuine problems.
3Reliability
If the screen arrangement is blocked, then filtration capacity is improved, but detection accuracy deteriorates due to incorrect blockage detection
Solution Approach 1:
The system establishes a baseline measurement of the degree of transmission before the wash cycle begins and compares it with measurements taken after evacuation. This preliminary reference state allows for accurate detection of actual blockages by comparing against known good conditions, reducing false positives.
Solution Approach 2:
The control facility uses multiple measurement points and compares transmission degrees across different states (filled vs. evacuated circulation chamber). This feedback comparison mechanism distinguishes between actual screen blockages and other factors affecting transmission, such as wash fluid turbidity or air pockets, thereby improving detection accuracy.
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 solution enhances the operational reliability of dishwashers by accurately detecting blockages and preventing residual wash fluid from affecting wash results, reducing incorrect detection and ensuring effective wash cycles.
Implementation Method 1
a first measuring step for determining a degree of transmission in the circulation chamber filled with wash fluid by means of an optical turbidity sensor
Data Source
AI summary
A dishwasher includes a controller controlling a cleaning cycle, a screen system for filtering a wash fluid, a circulation chamber and a collection chamber in fluid communication with the circulation chamber via a screen arrangement, a circulation pump for circulating the wash fluid and a drain pump for pumping out the wash fluid. During the cleaning cycle, to detect blockage in the screen arrangement, a degree of transmission in the circulation chamber filled with wash fluid is determined with an optical turbidity sensor in a first measuring step. The wash fluid is then pumped out of the collection chamber and the degree of transmission in the circulation chamber is again determined in a second measuring step. The change in the degree of transmission from the first measuring step to the second measuring step is then evaluated.