Household Appliance Filter Membrane Cleaning Using Variable Flow Speed

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Solution Overview

Problem

Filter systems in household appliances clog quickly, necessitating frequent cleaning to maintain efficiency and extend their operational lifespan.

Innovation Solution

A method involving a filter unit with a cleaning unit that employs distinct flow speeds during filtering and cleaning phases, where a higher speed is used for filtering and a lower speed or countercurrent for thorough membrane cleaning, preventing membrane sagging and ensuring effective dirt particle removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the filter membrane is cleaned frequently to maintain filtration efficiency, then the filter performance is improved, but the operational lifespan of the filter is reduced due to repeated cleaning cycles causing membrane wear and deformation

Engineering Contradiction:
Improvefiltration efficiencyVSAvoidfilter operational lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent implements periodic cleaning cycles with alternating flow directions. During operation, the filter processes fluid normally, then periodically reverses flow to clean the membrane by dislodging accumulated particles. This periodic action maintains high filtration efficiency while reducing the need for frequent intensive cleaning that would damage the membrane.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs reverse flow cleaning where the fluid flow direction is inverted during cleaning phases. This reverse flow lifts the filter membrane and flushes accumulated dirt particles off the membrane surface, effectively cleaning the filter without requiring mechanical contact that would cause wear and extend membrane lifespan.

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

2Productivity

If a high flow speed is used during filtering to increase processing capacity, then the productivity is improved, but the filter membrane sags and deformation occurs reducing cleaning effectiveness

Engineering Contradiction:
Improvefluid processing capacityVSAvoidmembrane shape stability
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The patent dynamically adjusts flow speed based on operational phase. During filtration, high flow speed is maintained for maximum productivity. During cleaning phases, the system transitions to lower flow speeds that prevent membrane sagging while still enabling effective particle removal, thus adapting flow characteristics to current operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system periodically alternates between high-speed filtration mode and low-speed cleaning mode. This periodic switching allows the membrane to maintain its shape during cleaning phases when low flow is used, while still achieving high productivity during filtration phases, resolving the contradiction between speed and shape stability.

Inventive Principle:
Principle #19Periodic action

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 enhances filter performance and extends the filter's operational time by ensuring thorough cleaning and preventing membrane deformation, allowing for continuous efficient filtration of fluids.

Implementation Method 1

a fluid-carrying household appliance (1) with a filter unit (27) for filtering fluids (14), the fluid-carrying household appliance (1) essentially comprising a receptacle (13), the receptacle (13) comprising an inlet opening (33) for fluids (14) and an outlet opening (17) for fluids (14), at least one pump unit (15) for essentially pumping the fluid (14)

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3954820A1Fluid-conducting domestic appliance
Publication Date: 2022.02.16 BSH HAUSGERATE GMBH
  • EP3954820A1 patent drawingFigure 1
  • EP3954820A1 patent drawingFigure 2
  • EP3954820A1 patent drawingFigure 3a

AI summary

The invention relates to a method for operating a fluid-carrying household appliance (1) with a filter unit (27) for filtering fluids (14), wherein the fluid (14) is pumped by at least one pump unit (15), and a filter membrane (39) of the filter unit (27) is cleaned by a cleaning unit (35), the method essentially comprising: at least one filtration process, wherein a filtration process comprises at least a first phase and at least a second phase, wherein during filtration the fluid (14) flows through the filter membrane (39) in the form of a volume flow, and during cleaning the filter membrane (39) the filter membrane (39) is cleaned by the cleaning unit (35), wherein in the at least one first phase the volume flow passes through the filter membrane (39) at a velocity v1, and that in the at least one second phase the volume flow passes through the filter membrane (39) at a velocity v2.wherein the filter membrane (39) is cleaned in at least one second phase and the velocity v2 of the volume flow differs from the velocity v1 of the volume flow.