Water-using domestic appliance and method for operating a water-using domestic appliance

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Solution Overview

Problem

Existing water-conducting household appliances, such as dishwashers, face challenges in effectively cleaning filter elements due to uneven distribution of cleaning fluids, leading to incomplete dirt removal and potential clogging.

Innovation Solution

A water-carrying household appliance with a pump pot and a nozzle device that generates an annular flow around the filter element in one direction, ensuring a homogeneous cleaning effect over 360° by using a nozzle device with fluid outlet openings that run tangentially to the tubular shape of the microfilter, and a drain pump to suck out washing liquid and dirt directly from the interior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional filter cleaning system is used with multiple spray nozzles, then the filter surface can be reached by cleaning fluid, but the cleaning effect is uneven and incomplete

Engineering Contradiction:
Improvecleaning uniformityVSAvoiddirt removal completeness
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

Instead of spraying cleaning fluid from the outside toward the filter interior (conventional approach), the invention introduces fluid through the filter interior and sprays it outward. This inverted approach allows the cleaning fluid to effectively reach and remove dirt from the interior surface where conventional spraying fails, achieving both uniform cleaning and complete dirt removal

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The cleaning system is divided into two distinct functional parts: an interior nozzle for introducing cleaning fluid through the filter interior, and an exterior nozzle for spraying fluid onto the outer surface. This segmentation allows each nozzle to perform its specific function optimally, ensuring comprehensive and uniform cleaning coverage

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If manual cleaning of the filter screen is required, then the filter can be cleaned, but it requires user intervention and time

Engineering Contradiction:
Improvecleaning convenienceVSAvoidcleaning time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The cleaning system is designed to automatically clean the filter element without requiring manual intervention. The pump circulates cleaning fluid through the interior and exterior nozzles, and the drain pump automatically removes the dirty water, enabling the filter to clean itself during the rinsing cycle

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention uses a hydraulic system with a pump to circulate cleaning fluid through the filter element and a drain pump to automatically evacuate the dirty water. This automated hydraulic cleaning system eliminates manual cleaning requirements and significantly reduces the time needed for filter maintenance

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If the pump pot is filled with water for rinsing, then the filter can be cleaned, but flow losses occur during the process

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidwater loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The drain pump is controlled based on feedback from the cleaning process - it activates when the dirty water level reaches a certain point and continues to evacuate water until the cleaning is complete. This feedback-controlled operation ensures effective cleaning while minimizing unnecessary water loss by only pumping out what is needed

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 solution achieves a comprehensive cleaning effect on the filter element, ensuring that dirt is effectively removed from both the inside and outside, reducing flow losses and allowing targeted operation of the annular flow during rinsing processes.

Implementation Method 1

the nozzle device is designed to generate an annular flow flowing around the filter element only in one flow direction between the pump pot and the filter element for detaching dirt from the filter element

Methodology Applied
Scientific EffectAnnular flow:

Implementation Method 2

the nozzle device with fluid outlet openings that run tangentially to the tubular shape of the microfilter

Methodology Applied
Scientific EffectFluid outlet openings running tangentially:

Implementation Method 3

a drain pump to suck out washing liquid and dirt directly from the interior

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3691507B1Water-using domestic appliance and method for operating a water-using domestic appliance
Publication Date: 2024.03.27 BSH HAUSGERATE GMBH
  • EP3691507B1 patent drawingFigure 1
  • EP3691507B1 patent drawingFigure 2
  • EP3691507B1 patent drawingFigure 3

AI summary

The invention relates to a water-using domestic appliance (1), in particular a domestic dishwasher, comprising a pump sump (17), a filter element (18), at least portions of which are arranged in the pump sump (17), and a nozzle unit (19) arranged on the pump sump (17), said nozzle unit (19) being designed to produce an annular flow (20) between the pump sump (17) and the filter element (18) in order to remove dirt from the filter element (18), said flow flowing around the filter element (18) only in one direction of flow (R).