Rotating Impeller Photocatalyst Unit for Compact UV Light Application

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Solution Overview

Problem

Conventional photocatalyst units face limitations in efficiently emitting UV light to photocatalysts, are restricted in size and thickness, and have limited design freedom in flow path structures, leading to increased cost and heat generation.

Innovation Solution

A photocatalyst unit with rotating blade plates carrying photocatalysts, where UV light is emitted from the outer peripheral side, allowing uniform light application and efficient decomposition of harmful substances without increasing the number of light sources or unit volume, featuring a crimped connection structure for stability and compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If UV lamps are arranged facing the photocatalyst filter surface, then UV light can be emitted to the photocatalyst, but the unit thickness increases and design freedom is restricted

Engineering Contradiction:
ImproveUV light emission to photocatalystVSAvoidunit thickness
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent changes the arrangement dimension of UV lamps from facing the photocatalyst filter surface (thickness direction) to arranging along the airflow direction (length direction). This dimensional change allows UV light to be emitted to the photocatalyst while maintaining a compact unit thickness and providing design freedom.

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

2Ease of operation

If air flows between UV lamps, then air can pass through the unit, but the number of UV lamps is restricted due to air resistance

Engineering Contradiction:
Improveair flow through unitVSAvoidnumber of UV lamps
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent segments the air flow path by introducing a partition plate that divides the airflow into multiple channels. This segmentation allows air to flow efficiently while enabling the arrangement of multiple UV lamps along the airflow direction without excessive air resistance, as each lamp is positioned in a dedicated flow channel.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If photocatalyst is carried deep inside air passage holes, then more photocatalyst can be provided, but UV light application becomes inefficient

Engineering Contradiction:
Improveamount of photocatalystVSAvoidUV light application efficiency
Core Design Contradiction:
Quantity of substanceVSIllumination intensity

Solution Approach 1:

The patent changes the UV light application approach from illuminating deep inside air passage holes (vertical illumination) to illuminating the photocatalyst on the surface of airflow-guiding plates along the airflow direction (horizontal illumination). This dimensional change ensures efficient UV light application while maintaining a large amount of photocatalyst.

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

4Object-affected harmful factors

If conventional photocatalyst filter and UV lamp arrangement is used, then air cleaning function is provided, but the unit becomes larger and more expensive

Engineering Contradiction:
Improveair cleaning effectVSAvoidunit size
Core Design Contradiction:
Object-affected harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent merges multiple functions into a single integrated structure: the airflow-guiding plates serve both as airflow channels and as carriers for photocatalyst, while also being illuminated by UV lamps. This merging eliminates the need for separate components, reducing unit size and cost while maintaining air cleaning effectiveness.

Inventive Principle:
Principle #5Merging (Combining)

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 unit achieves efficient photocatalytic decomposition with reduced size and cost, maintaining stability at high speeds and preventing heat buildup, while allowing flexible flow path design.

Implementation Method 1

the photocatalyst excited by UV light decomposes and removes harmful substances in the air

Methodology Applied
Scientific EffectPhotocatalytic decomposition: Photo-oxidation

Data Source

PatentEP4374961B1Photocatalyst unit and method for manufacturing photocatalyst unit
Publication Date: 2026.02.11 JAPAN
  • EP4374961B1 patent drawingFigure 1
  • EP4374961B1 patent drawingFigure 2
  • EP4374961B1 patent drawingFigure 3

AI summary

Provided is a photocatalyst unit that (i) can improve a fluid cleaning effect of the photocatalyst by efficiently emitting UV light to a photocatalyst, (ii) can be formed thin and compact as a photocatalyst unit including a photocatalyst filter and a light emitting unit, (iii) has a high degree of freedom in designing a flow path structure, and (iv) can obtain a sufficient cleaning effect as a whole without increasing a volume of light or the number of light sources. [Solution means] A photocatalyst carrier is a blower fan like impeller or a cross flow fan like impeller, or an impeller serving as a blower fan or an impeller serving as a cross flow fan. An impeller 4 includes a pair of connecting plates 42, 43 that connect to each blade plate 41 at both ends thereof in an axial direction 40. Each blade plate 41 and the connecting plates 42, 43 are fixed in a manner that a part of each of the both ends of the blade plate penetrates and protrudes through a through groove formed in each of the connecting plates, and the protruding part is bent in a direction intersecting the axial direction and parallel to a surface of the blade plate so as to be crimped and fixed to an opening periphery of the through groove of the connecting plate.