Concentric Multi-Layer Hood Filter for Extended Activated Carbon Life

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Solution Overview

Problem

Existing recirculating hoods with activated carbon filters face a decline in effectiveness over time due to the loss of adsorbing capacity, leading to incomplete odor elimination and reduced filter efficiency.

Innovation Solution

A hood filter design featuring a pleated textile layer followed by a granular activated carbon layer, arranged concentrically to maximize filtering surface area, with an air flow inlet on the base for improved airflow and a compact, efficient filtration system, including a stainless steel housing for easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single activated carbon filter layer is used, then the filter can adsorb odors effectively, but the adsorbing capacity is lost after certain working hours, reducing filter efficiency

Engineering Contradiction:
Improvefilter efficiencyVSAvoidservice life of activated carbon
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The filter is divided into multiple functional layers: a pre-filter layer for capturing larger particles, an activated carbon layer for odor adsorption, and a hydrophobic membrane layer for moisture separation. This segmentation allows each layer to perform its specific function optimally, extending the overall filter service life by preventing premature saturation of the activated carbon layer

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pre-filter layer performs preliminary filtration of grease particles and larger contaminants before air reaches the activated carbon layer. This preliminary action protects the activated carbon from rapid saturation, maintaining its adsorbing capacity for longer periods and extending the effective service life of the filter

Inventive Principle:
Principle #10Preliminary action

2Area of stationary object

If the filter element size is increased to improve filtering performance, then the filtering surface area increases, but the occupied volume increases, making it unsuitable for compact household hoods

Engineering Contradiction:
Improvefiltering surface areaVSAvoidoccupied volume
Core Design Contradiction:
Area of stationary objectVSVolume of stationary object

Solution Approach 1:

The filter elements are arranged in a nested concentric configuration with multiple layers positioned one inside another. The pre-filter, activated carbon layer, and hydrophobic membrane are arranged in concentric cylinders, maximizing the filtering surface area within a compact cylindrical volume suitable for household hood installations

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The filter transitions from a flat two-dimensional arrangement to a three-dimensional concentric cylindrical structure. This dimensional change allows the filtering surface to be distributed across multiple radial layers, dramatically increasing the total filtering area while maintaining a compact overall volume that fits within standard household hood constraints

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

3Productivity

If activated carbon is exposed directly to air flow, then odor filtration occurs, but the activated carbon loses adsorbing capacity quickly, reducing effectiveness

Engineering Contradiction:
Improveodor elimination rateVSAvoidservice life of activated carbon
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The pre-filter layer performs preliminary filtration of grease particles and larger contaminants before air reaches the activated carbon layer. This preliminary action protects the activated carbon from rapid saturation, maintaining its adsorbing capacity for longer periods

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hydrophobic membrane layer with its porous structure allows selective passage of air and water vapor while blocking grease particles. This porous material protects the activated carbon from direct exposure to grease-laden air, extending its service life while maintaining odor elimination productivity

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

Enhances odor elimination efficiency and extends the life of activated carbon, providing a more effective and durable filtration system for household environments.

Implementation Method 1

The filter comprises a pleated filtering textile

Methodology Applied
Scientific EffectPhysical barrier filtration: Filter (physical)

Implementation Method 2

the second filtering layer comprises activated carbon

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2839220B1Range hood comprising an odour filter
Publication Date: 2021.02.24 WHIRLPOOL EMEA SPA
  • EP2839220B1 patent drawingFigure 1~2
  • EP2839220B1 patent drawingFigure 3~4
  • EP2839220B1 patent drawingFigure 5~6

AI summary

The present invention relates to a filter (105) for a hood (101), comprising at least two filtering layers (401, 402) arranged consecutively along the direction of flow; the filter (105) has a substantially cylindrical shape, thus defining a lateral filtering surface (503), wherein said filtering layers (401, 402) are arranged concentrically on the lateral surface (503), being placed one inside the other. The present invention further relates to a filter- housing assembly, which comprises a housing (106) for receiving the filter (105), wherein the housing (106) comprises at least one bottom aperture (301) providing a fluidic connection between a hood (101) and the filter (105), and further comprises at least one aperture for the outflow of filtered air from said filter (105). Finally, the present invention relates to a hood, such as an extraction hood or a recirculating hood.