Ball Bed Filter Backwash for Self-Cleaning Washing Machines

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Household appliances with circulation systems and integrated filters often require frequent user cleaning due to accumulated impurities, which can also contaminate measuring devices, leading to system blockages and inefficiencies.

Innovation Solution

Incorporating a self-cleaning ball bed or granulate filter with a gravity-driven backwash system, where a water column is built to create pressure for cleaning, and a flow-shaping element to favor peripheral flow, ensuring the filter remains immersed and effectively cleans both the filter and pre-filter by reversing flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter is integrated into the pipe system to remove impurities, then the process water quality is improved, but the filter accumulates deposits over time requiring frequent user cleaning

Engineering Contradiction:
Improveprocess water qualityVSAvoidfilter cleaning frequency
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The filter system performs self-cleaning through a backwash mechanism where water flows in reverse through the filter bed, lifting and fluidizing the filter media to dislodge and remove accumulated deposits. This automated self-service function eliminates the need for frequent manual user cleaning while maintaining continuous filtration effectiveness.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The filter operates in periodic cycles between normal filtration mode and backwash cleaning mode. During periodic backwash cycles, water flow is reversed to clean the filter media, allowing the system to maintain high reliability without requiring continuous manual intervention. This periodic action resolves the contradiction by automating maintenance.

Inventive Principle:
Principle #19Periodic action

2Reliability

If a filter is integrated into the pipe system to remove impurities, then the process water quality is improved, but the measuring device becomes contaminated over time

Engineering Contradiction:
Improveprocess water qualityVSAvoidmeasuring device contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The measuring device is extracted from the main filtration path and placed in a separate bypass line. This allows the measuring device to receive clean, pre-filtered water while the main filter handles the heavy filtration load. The separation protects the measuring device from contamination while maintaining accurate measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A T-piece connection acts as an intermediary that divides the water flow into two paths: one through the main filter and another through the measuring device. This intermediary structure allows the measuring device to sample water quality without being directly exposed to the contaminated stream that passes through the filter, preventing contamination while maintaining measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If water pressure is used to drive the backwash, then the cleaning effectiveness is improved, but the system becomes dependent on high water pressure which may not always be available

Engineering Contradiction:
Improvebackwash effectivenessVSAvoidwater pressure dependency
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The backwash system uses a water column of sufficient height to create hydrostatic pressure that is independent of the main water supply pressure. By utilizing gravity-driven flow from an elevated water source, the system achieves consistent backwash effectiveness without dependency on high water pressure availability. This equipotential approach using gravitational potential energy resolves the contradiction.

Inventive Principle:
Principle #12Equipotentiality

Solution Approach 2:

The system employs hydraulic principles using a gravity-driven water column to generate the necessary backwash pressure. Instead of relying on high-pressure water supply systems, the design uses hydrostatic pressure from an elevated water reservoir, making the backwash effectiveness independent of water pressure fluctuations while maintaining cleaning capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 configuration significantly reduces the need for user cleaning, prevents contamination of measuring devices, and maintains filter efficiency by regularly flushing out deposits, ensuring continuous operation and accurate process water monitoring.

Implementation Method 1

The pressure required for backwashing is preferably built up by building up a water column

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Increase

Implementation Method 2

The self-cleaning system or regeneration system of the filter has in particular a backwash that is driven by gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 3

at least one ball bed filter or granulate filter in the line system

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP2816150B1Water-conducting domestic appliance with lye filter
Publication Date: 2018.03.14 V-ZUG AG
  • EP2816150B1 patent drawingFigure 1
  • EP2816150B1 patent drawingFigure 2A
  • EP2816150B1 patent drawingFigure 2B

AI summary

Water-bearing household appliance, in particular a washing machine and/or a dishwasher, with a tub (1) for storing items to be cleaned, a line system (8, 12) for process liquid connected to the tub and with a spherical bed filter (11 ) for cleaning the process liquid from solids.