Exhaust hood with electrostatic filter unit

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Solution Overview

Problem

Existing cooker hoods with electrostatic filters face challenges in achieving sufficient filter efficiency with a simple design while ensuring safe use, as they often require high space and pose safety risks to users.

Innovation Solution

An electrostatic filter unit with an ionization unit and separation unit, utilizing air-permeable precipitation electrodes and protective elements, which combines mechanical and electrostatic filtering mechanisms, and includes a high-voltage transformer integrated into the filter unit for safe operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrostatic filters with plate electrodes and wire ionization elements are used, then filter efficiency can be achieved, but the device takes up a lot of space and poses safety dangers to users

Engineering Contradiction:
Improvefilter efficiencyVSAvoidspace requirement
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent applies porous precipitation electrodes instead of conventional solid plate electrodes. These porous electrodes provide a large internal surface area for particle collection while maintaining a compact external footprint. The porous structure allows air to pass through while capturing particles electrostatically, resolving the contradiction between filter efficiency and space requirement

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent integrates the high-voltage transformer directly into the filter unit housing, nesting the power supply component within the existing structure. This eliminates the need for separate external power supplies and reduces overall device volume while maintaining filter efficiency

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If conventional electrostatic filters with plate electrodes are used, then filter efficiency can be achieved, but the design becomes complex and safety risks increase

Engineering Contradiction:
Improvefilter efficiencyVSAvoiddesign complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the precipitation function and ionization function into a single integrated filter element. The porous precipitation electrodes serve both as the collection surface and as part of the electrostatic field generation system, simplifying the overall design while maintaining filter efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a conductive housing that serves as an intermediary between the high-voltage transformer and the porous precipitation electrodes. This conductive housing acts as an electrostatic shield, simplifying the electrical design by providing a reference potential and reducing the need for complex insulation arrangements

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If conventional electrostatic filters are used, then particle filtration can be achieved, but user safety is compromised due to electrical hazards

Engineering Contradiction:
Improveparticle filtrationVSAvoidelectrical hazard
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful high-voltage electrical field into a beneficial electrostatic precipitation mechanism. By using porous electrodes with controlled conductivity and integrating the high-voltage transformer safely, the electrical energy that could be hazardous is instead used to create the electrostatic field necessary for efficient particle capture

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The porous precipitation electrodes provide a large surface area distributed throughout a compact volume, which reduces the voltage gradient and electrical field intensity at any single point. This reduces electrical hazard while maintaining filtration efficiency through the cumulative effect of numerous small collection surfaces

Inventive Principle:
Principle #31Porous materials

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

The solution provides enhanced filter efficiency for particles with hydraulic diameters ≥ 0.001 µm, reduces space requirements, and ensures user safety by integrating protective elements and using air-permeable electrodes, maintaining efficiency even at low flow velocities and preventing electrical hazards.

Implementation Method 1

solid and liquid particles are electrostatically charged by means of corona discharge via the ionization electrode

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Implementation Method 2

the particles are deposited at the electrodes and thus filtered out of the air

Methodology Applied
Scientific EffectElectrostatic deposition: Electrostatic Deposition

Data Source

PatentEP4048955B1Exhaust hood with electrostatic filter unit
Publication Date: 2026.03.11 BSH HAUSGERATE GMBH
  • EP4048955B1 patent drawingFigure 1
  • EP4048955B1 patent drawingFigure 2
  • EP4048955B1 patent drawingFigure 3

AI summary

The present invention relates to an electrostatic filter unit for an air cleaning device, wherein the filter unit (2) comprises an ionization unit (100) and a separation unit (170) with at least two collecting electrodes (17, 19). The electrostatic filter unit is characterized in that the at least two collecting electrodes (17, 19) are air-permeable and that the filter unit (2) comprises at least one protection element for at least one of the elements of the ionization unit (100). The invention further relates to an air cleaning device (1) comprising a filter unit according to the invention.