Dirt filter for a vacuum cleaner

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Solution Overview

Problem

Dirt separators in vacuum cleaners, especially those using porous filter elements, become clogged with increasing dirt loads, leading to decreased filter performance, while cyclone-based separators are less efficient with fine dirt particles.

Innovation Solution

A dirt separator design featuring a cylindrical vessel with a radial wall and a movable guide element that accelerates airflow through the inlet, enhancing centrifugal force for better separation of coarse particles and preventing clogging, combined with a coaxial flow-through filter element for retaining fine particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a porous filter element is used to separate dirt particles from air flow, then fine dirt particles can be retained effectively, but the filter element becomes clogged with increasing dirt loads leading to decreased filter performance

Engineering Contradiction:
Improvefilter performanceVSAvoidclogging resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The dirt separator is divided into two functional segments: a cyclone-based separator for coarse particles and a porous filter element for fine particles. This segmentation allows each component to handle specific particle sizes, preventing the filter element from being overwhelmed by coarse debris that would cause rapid clogging.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cyclone-based separator acts as an intermediary component between the air intake and the filter element. It pre-separates coarse dirt particles from the air flow before the air reaches the filter element, reducing the load on the filter and delaying clogging.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a cyclone-based dirt separator is used to handle coarse particles, then the separator is less prone to clogging, but it is less efficient at retaining fine dirt particles

Engineering Contradiction:
Improveclogging resistanceVSAvoidfilter performance
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The separation system is segmented into two stages: cyclone separation for coarse particles and filtration through a porous element for fine particles. Each stage is optimized for its specific function, with the cyclone handling high-volume coarse particle removal and the filter providing fine particle capture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the dirt separator have different separation mechanisms tailored to local needs: the cyclone chamber uses centrifugal force for coarse particles, while the filter element uses porous filtration for fine particles. This local optimization ensures each component operates at peak efficiency for its designated particle size range.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If the inlet cross-section is reduced to accelerate air flow and enhance centrifugal force, then separation performance improves, but the air flow resistance increases

Engineering Contradiction:
Improveseparation performanceVSAvoidair flow resistance
Core Design Contradiction:
Measurement precisionVSStress or pressure

Solution Approach 1:

The guide element is designed to be movable rather than fixed, allowing it to dynamically adjust the inlet opening size based on operating conditions. This dynamic adjustment optimizes the balance between air flow acceleration (for separation performance) and air flow resistance, adapting to varying load conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of inlet cross-sectional area dynamically through the movable guide element. By adjusting this parameter, the system optimizes air flow velocity and centrifugal force for separation while managing air flow resistance, rather than using a fixed small opening that would always create high resistance.

Inventive Principle:
Principle #35Parameter changes

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 design maintains improved filter performance across a wide dirt load range, reduces the risk of long hair or threads wrapping around the filter, and minimizes the need for frequent emptying, thereby enhancing the overall efficiency and usability of the vacuum cleaner.

Implementation Method 1

Dirt particles in the air are transported radially outwards by centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

The acceleration of the air flow can be the effect of a narrowing of the inlet, with a cross-section through which the flow passes being locally reduced in the manner of a nozzle

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 3

The filter element can further clean the air flow. Coarse dirt particles in particular can be better removed from the air flow by means of the cyclone-based part of the dirt separator, so that the filter element can better retain fine dirt particles

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 4

Another known embodiment includes a cyclone filter in which the dirt-laden air is guided on a circular path. Dirt particles in the air are transported radially outwards by centrifugal force

Methodology Applied
Scientific EffectCyclone separation: Cyclone Separation

Implementation Method 5

a vane mounted in the inlet to direct the airflow radially outward toward the vessel wall and increase a velocity of the airflow

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP4066712A1Dirt filter for a vacuum cleaner
Publication Date: 2022.10.05 BSH HAUSGERATE GMBH
  • EP4066712A1 patent drawingFigure 1
  • EP4066712A1 patent drawingFigure 2
  • EP4066712A1 patent drawingFigure 3

AI summary

A dirt separator for a vacuum cleaner comprises a cylindrical vessel with a longitudinal axis and a radial vessel wall; a filter element mounted in the vessel at a circumferential distance from the vessel wall; an inlet for introducing an airflow into a region located radially between the filter element and the vessel wall; and a guide element mounted in the inlet to direct the airflow radially outwards towards the vessel wall and to increase the velocity of the airflow; wherein the guide element is movably arranged such that the increase is variable depending on an airflow passing through the inlet.