Electronic air cleaner and method

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Solution Overview

Problem

Conventional electronic air cleaners (EACs) face challenges such as frequent cleaning and replacement needs, airflow resistance, and contamination of corona wires due to particle re-entrainment and ozone production, which increase energy consumption and maintenance costs in HVAC systems.

Innovation Solution

The use of an electronic air cleaner with a housing containing a plurality of first and second electrodes, both configured parallel to airflow, where the first electrodes have a high electrical resistivity and a porous, open-cell structure to collect particulate matter deep within the material, reducing surface accumulation and agglomeration, and repelling electrodes to direct charged particles effectively, minimizing pressure drop and extending cleaning intervals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional EACs use smooth metal collecting electrode plates parallel to airflow, then particle collection is achieved through electrostatic attraction, but particles accumulate on the outer surface and become re-entrained in the airflow, reducing filtration effectiveness

Engineering Contradiction:
Improvefiltration effectivenessVSAvoidparticle re-entrainment
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies porous materials by lining the collecting electrodes with open-cell foam material that allows particles to be collected within the porous structure rather than on the outer surface. The porous structure has interconnected cells that trap particles deep within the material, preventing re-entrainment while maintaining electrostatic collection efficiency.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent transitions from surface collection (2D) to volumetric collection (3D) by using open-cell foam material. Particles are collected throughout the volume of the porous structure rather than just on the surface, effectively utilizing the third dimension to increase collection capacity and prevent re-entrainment.

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

2Reliability

If fibrous media filters are placed perpendicular to airflow to mechanically remove particles, then particle collection is achieved, but airflow resistance and static pressure differential increase significantly

Engineering Contradiction:
Improveparticle collectionVSAvoidairflow resistance
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The patent replaces the mechanical filtration system (fibrous media perpendicular to airflow) with an electrostatic system. Collecting electrodes are positioned parallel to airflow direction, and charged particles are removed through electrostatic attraction to the electrodes rather than mechanical interception, significantly reducing airflow resistance.

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

Solution Approach 2:

The patent changes the orientation parameter of the collecting electrodes from perpendicular to parallel relative to the airflow direction. This parameter change, combined with electrostatic collection mechanism, allows particles to be removed without creating significant pressure drop across the filter.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If corona electrodes are used to ionize air and charge particles, then electrostatic particle collection is enabled, but corona wires become contaminated by oxidation and deposits, requiring frequent cleaning

Engineering Contradiction:
Improveelectrostatic collection efficiencyVSAvoidcleaning interval
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent uses open-cell foam material with controlled porosity (20-80% open cell structure) that allows ion penetration while providing a large surface area for particle collection. The porous structure prevents particle buildup that would insulate the collecting electrodes, maintaining electrostatic efficiency over extended periods.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent creates a composite structure by combining the conducting foam material with an open-cell foam substrate. This composite provides both electrical conductivity for charge collection and porous structure for particle trapping, extending the operational life before cleaning is required.

Inventive Principle:
Principle #40Composite materials

4Reliability

If collecting electrodes accumulate particle layers to remove particles from airflow, then particle removal is achieved, but the accumulated particles increase airflow resistance and energy consumption

Engineering Contradiction:
Improveparticle removalVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs open-cell foam material that provides extensive internal surface area within a compact volume. Particles are distributed throughout the porous structure rather than forming thick surface layers, maintaining low airflow resistance and energy consumption while achieving effective particle removal.

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

This configuration significantly reduces airflow resistance, extends cleaning intervals, and minimizes the need for frequent maintenance by effectively collecting and retaining particulate matter within the open-cell porous material, enhancing the air filtration efficiency and reducing energy consumption.

Implementation Method 1

creating an electric field using an ionizer arranged in an airflow path, such that the ionizer is positioned to ionize at least a portion of air molecules from the airflow

Methodology Applied
Scientific EffectIonization: Ionisation

Implementation Method 2

applying a first electric potential at a plurality of first electrodes spaced apart from the ionizer, and receiving, at the first collection portion, particulate matter electrically coupled to the ionized air molecules

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP2849888B1Electronic air cleaner and method
Publication Date: 2021.05.12 UNIVERSITY OF WASHINGTON THROUGH ITS CENTER FOR COMMERCIALIZATION
  • EP2849888B1 patent drawingFigure 1A
  • EP2849888B1 patent drawingFigure 1B
  • EP2849888B1 patent drawingFigure 1C

AI summary

Electronic air cleaners for use in heating, air-conditioning, and ventilation (HVAC) systems and associated methods and systems are disclosed herein. In one embodiment, an electronic air cleaner (100, 200, 300) includes one or more collecting electrodes (122, 322) having a collection material with a porous, open-cell structure and a conductive internal portion (125, 325). The collection material can be configured to collect and receive charged particulate matter in an airflow path. After a period of time, used collection material can be removed from individual collecting electrodes (122, 322) and replaced with new collection material.