Ceramic Plasma Electrode Filter for Extractor Hood Odor Elimination

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Solution Overview

Problem

Existing vapor extraction devices face inefficiencies in odor filtration due to limited service life of activated carbon and zeolite filters, and insufficient odor neutralization by plasma filters, which also suffer from electrochemical corrosion.

Innovation Solution

A filter unit with a ceramic substrate acting as a dielectric, housing a high-voltage electrode and counter-electrode, forming a plasma electrode that generates non-thermal plasma for efficient odor elimination, while being protected against electrochemical corrosion and easy to clean.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If activated carbon filters or zeolite filters are used for odor filtration, then odor filtration is achieved, but the filter lifespan is limited and filter efficiency decreases over time

Engineering Contradiction:
Improvefilter efficiencyVSAvoidfilter lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the mechanical/physical adsorption system (activated carbon or zeolite filters) with a plasma-based chemical treatment system. The plasma electrode generates reactive species that actively neutralize odorous compounds in the air stream, eliminating the need for consumable filter media that requires replacement. This substitution maintains high filter efficiency indefinitely without the lifespan limitations of adsorbent materials.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameter from passive adsorption to active plasma generation. By applying high voltage to the plasma electrode, the system creates a plasma field that continuously treats the air stream, transforming the filtration mechanism from a consumable material-based system to an energy-driven system with sustained effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If plasma electrodes are used for odor neutralization, then odor neutralization is achieved, but the air does not come into complete contact with plasma and VOCs are only partially broken down

Engineering Contradiction:
Improveodor neutralization efficiencyVSAvoidplasma-air contact completeness
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The plasma electrode incorporates a porous or perforated structure that allows the air stream to pass through multiple pathways in close proximity to the plasma generation surface. This increases the surface area contact between the air containing odorous compounds and the generated plasma, ensuring more complete interaction and breakdown of VOCs compared to solid plasma electrode surfaces.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent transitions from a two-dimensional surface plasma generation to a three-dimensional plasma distribution by using a porous electrode structure. This allows plasma to be generated throughout the volume of the electrode rather than just on the external surface, creating multiple contact zones that enhance the completeness of plasma-air interaction.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If plasma electrodes are used for odor neutralization, then plasma generation is achieved, but electrochemical corrosion protection is inadequate

Engineering Contradiction:
Improveplasma generation capabilityVSAvoidelectrode service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The plasma electrode is constructed as a composite structure combining a corrosion-resistant substrate (such as stainless steel or ceramic) with a plasma-active surface layer. This composite design maintains the plasma generation capability while providing inherent protection against electrochemical corrosion from the kitchen environment, significantly extending the electrode's service life.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs a modular plasma electrode design where the corrosion-prone components can be easily replaced or the entire electrode assembly is designed as a replaceable unit. This approach acknowledges that while plasma generation is essential, the electrode may eventually degrade and can be swapped out without requiring complex repair procedures, maintaining system reliability through simplicity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 filter unit achieves enhanced odor elimination efficiency and extended service life by ensuring homogeneous air-plasma mixing and protection against corrosion, allowing for effective operation in recirculation mode without the need for frequent replacements.

Implementation Method 1

The plasma electrode (1) comprises a substrate (5) acting as a dielectric, a high-voltage electrode (7), and at least one counter electrode (6). When a voltage is applied, a surface plasma (8) is generated on the substrate for odor elimination.

Methodology Applied
Scientific EffectDielectric barrier discharge: Plasma

Implementation Method 2

The air flows parallel to the surface of the plasma electrode. These plasma electrodes have the significant disadvantage that the air flowing along the plasma electrode does not come into complete contact with the generated plasma.

Methodology Applied
Scientific EffectSurface plasma: Plasma

Implementation Method 3

The substrate (5) consists of ceramic material and represents an air-permeable structure with at least one opening (4). At least the high-voltage electrode (7) is embedded in the substrate (5).

Methodology Applied
Scientific EffectDielectric: Dielectric

Data Source

PatentEP4190430A1Filter unit for an extractor hood and extractor hood
Publication Date: 2023.06.07 BSH HAUSGERATE GMBH
  • EP4190430A1 patent drawingFigure 1~2
  • EP4190430A1 patent drawingFigure 3~4
  • EP4190430A1 patent drawingFigure 5a~6b

AI summary

The present invention relates to a filter unit for a fume hood, wherein the filter unit (12) comprises at least one plasma electrode (1) comprising a substrate (5) acting as a dielectric, a high-voltage electrode (7), and at least one counter electrode (6). The filter unit (12) is characterized in that the substrate (5) consists of ceramic material, that the substrate (5) is an air-permeable structure with at least one opening (4), and that at least the high-voltage electrode (7) is embedded in the substrate (5). Furthermore, a fume hood with at least one filter unit (12) is described.