Angled Perforated Plasma Filter Unit for Compact VOC Breakdown

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Solution Overview

Problem

Existing air filtration systems in extractor devices, such as extractor hoods and downdraft fans, face limitations in filter efficiency due to clogging and limited service life of activated carbon and zeolite filters, and inadequate odor neutralization by plasma filters, which require large installation spaces and have reduced effectiveness in breaking down volatile organic compounds (VOCs).

Innovation Solution

A filter unit with a perforated plasma electrode element housed at an angle to the airflow direction, utilizing dielectric barrier discharge to generate non-thermal plasma, which is enhanced by a mixing element for homogeneous mixing of reactive species and an ozone barrier to prevent ozone escape, reducing installation space and improving VOC breakdown efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plasma electrodes are oriented parallel to the airflow direction to form an airtight unit, then the plasma filter can be installed, but the installation space becomes large and air contact with plasma is incomplete

Engineering Contradiction:
Improveodor neutralization effectivenessVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The plasma electrode element is rotated from a parallel orientation to a perpendicular orientation relative to the airflow direction. This dimensional change allows the airflow to pass through the plasma-generated region more effectively, improving contact between air and plasma while reducing the installation space required for the plasma filter.

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

2Reliability

If activated carbon filters or zeolite filters are used for odor filtration, then odor and VOC removal is achieved, but the filters become clogged over time and have limited lifespan

Engineering Contradiction:
Improveodor filtration efficiencyVSAvoidfilter service life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the mechanical adsorption-based filtration system (activated carbon/zeolite filters that physically trap molecules) with a plasma-based chemical treatment system. The plasma generates reactive oxygen and nitrogen species that chemically break down odor molecules and VOCs, eliminating the clogging issue inherent in physical filters and extending service life.

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

3Volume of stationary object

If plasma electrode elements are arranged perpendicular to the flow direction, then installation space is reduced, but air may not come into complete contact with the generated plasma

Engineering Contradiction:
Improveinstallation depthVSAvoidVOC breakdown efficiency
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The plasma electrode element is designed with a perforated structure featuring multiple openings distributed across its surface. This segmentation allows airflow to pass through multiple points simultaneously, ensuring complete contact with the plasma-generated region while maintaining the perpendicular orientation that reduces installation depth. The perforations create multiple interaction zones between air and plasma.

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

The solution enhances VOC breakdown efficiency, extends filter service life, reduces installation space requirements, and ensures homogeneous ozone distribution, leading to improved air purification and reduced noise from airflow deflections.

Implementation Method 1

The plasma electrode element is connected to a power source to generate the plasma required for air purification. The at least one plasma electrode element has a perforated structure, and the at least one plasma electrode element is arranged in the housing at an angle other than 90° to the flow direction.

Methodology Applied
Scientific EffectDielectric barrier discharge: Plasma

Implementation Method 2

The core component of these plasma filters is the plasma electrode, which generates the actual plasma and forms an airtight unit. This plasma is generated on the surface of the plasma electrode and is therefore also referred to as surface plasma. The air flows parallel to the surface of the plasma electrode.

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP4269879A1Filter unit for an extractor hood and extractor hood
Publication Date: 2023.11.01 BSH HAUSGERATE GMBH
  • EP4269879A1 patent drawingFigure 1
  • EP4269879A1 patent drawingFigure 2
  • EP4269879A1 patent drawingFigure 3

AI summary

The present invention relates to a filter unit for a range hood, wherein the filter unit (1) comprises at least one plasma electrode element (13). The filter unit (1) is characterized in that the at least one plasma electrode element (13) is received in a housing (10) with an air inlet opening (102) and at least one air outlet opening (103), the at least one plasma electrode element (13) has a perforated structure, and the at least one plasma electrode element (13) is arranged in the housing (10) at an angle other than 90° to the flow direction (S). A range hood with such a filter unit (1) is also described.