Dishwasher Dual Filtration to Prevent Fine Filter Clogging

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Dishwasher appliances face inefficiencies in filtering wash fluid due to clogging issues with fine particle filters, which can lead to repeated draining and refilling cycles, wasting water and reducing cleanliness, as conventional methods either clog easily or fail to remove smaller particles effectively.

Innovation Solution

Implementing a dual filtration system using a fine filtration medium for cross-flow filtration and a coarse filtration medium for dead-end filtration, with a diverter valve and two pumps to direct filtered fluid to the spray assembly and unfiltered fluid to a drain, preventing clogging and maintaining cleanliness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a fine particle filter is used to remove small particles from wash fluid, then the cleanliness of articles is improved, but the filter becomes clogged during early wash stages

Engineering Contradiction:

Improvecleanliness of articlesVSAvoidfilter clogging

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The filtration system is segmented into two distinct filters: a first filter with larger pores for capturing large particles, and a second filter with smaller pores for capturing fine particles. This segmentation allows each filter to specialize in a particular particle size range, preventing the fine particle filter from being overwhelmed and clogged by large debris during early wash stages while still achieving high cleanliness standards.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a coarse filter is used to prevent clogging, then filter reliability is improved, but the ability to remove small particles is lost

Engineering Contradiction:

Improvefilter clogging resistanceVSAvoidremoval of small particles

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The filtration system is divided into two sequential stages: a first filter with larger pore size that captures coarse particles and maintains reliable operation, followed by a second filter with smaller pore size that removes fine particles to achieve high cleanliness. This segmentation allows the system to maintain both clogging resistance and fine particle removal capability simultaneously.

Inventive Principle:

Principle #1Segmentation

3Reliability

If the filter is drained and refilled to unclog it, then filter operation is restored, but water and energy are wasted

Engineering Contradiction:

Improvefilter operationVSAvoidwater and energy consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

By segmenting the filtration into two filters with different pore sizes, the system prevents clogging of the fine particle filter in the first place. Large particles are captured by the first filter, allowing the second filter to operate continuously without clogging, thereby eliminating the need for draining and refilling operations and avoiding associated water and energy waste.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first filter acts as an intermediary protective element that captures large particles before they can reach and clog the second filter. This intermediary filtration layer preserves the operation of the fine particle filter, preventing the need for costly drain-and-refill cycles.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Device complexity

If a single filter captures all particle sizes, then device complexity is reduced, but filtration effectiveness for both large and small particles is compromised

Engineering Contradiction:

Improvenumber of filtersVSAvoidfiltration effectiveness

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

Rather than using a single filter that would need to balance conflicting pore size requirements, the system segments filtration into two specialized filters. The first filter handles large particles with larger pores, while the second filter handles fine particles with smaller pores. This segmentation achieves superior overall filtration effectiveness compared to a single filter design.

Inventive Principle:

Principle #1Segmentation

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 method effectively reduces filter clogging, improves water and energy efficiency, and ensures cleaner wash fluid by separating and managing particle sizes, enhancing the overall cleaning performance of the dishwasher.

Implementation Method 1

finely filtering wash fluid with a fine filtration medium via cross-flow filtration

Methodology Applied

Scientific EffectCross-flow filtration: Filter (physical)

Implementation Method 2

coarsely filtering wash fluid with a coarse filtration medium via dead-end filtration

Methodology Applied

Scientific EffectDead-end filtration: Filter (physical)

Data Source

PatentUS9968236B2Dishwasher appliance and a method for operating the same

Publication Date: 2018.05.15 HAIER US APPLIANCE SOLUTIONS INC

AI summary

The present subject matter provides a method for operating a dishwasher appliance. The method includes finely filtering wash fluid with a fine filtration medium via cross-flow filtration and coarsely filtering wash fluid with a coarse filtration medium via dead-end filtration. The finely filtered wash fluid is directed to a spray assembly of the dishwasher appliance. A related dishwasher appliance is also provided.