Ultraviolet Irradiation Device Flow Straightening Chamber

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Solution Overview

Problem

Conventional ultraviolet light irradiation devices for fluid sterilization face challenges in maintaining consistent ultraviolet light dosages due to variations in flow velocity caused by assembly errors, leading to inadequate sterilization in high velocity regions and potential biofilm formation.

Innovation Solution

The device incorporates a cylindrical processing flow path with a first chamber covering one end, an inflow portion, an outflow portion, and a light emitting element, where the first chamber's inner volume is optimized to be at least 2/3 of the cube of the equivalent inner diameter of the processing flow path and up to 3 times its inner volume, along with a flow straightening mechanism to regulate flow velocity and prevent biofilm formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gaps between the ends of the processing flow path and the facing members are made small to increase pressure loss, then the flow velocity can be adjusted, but assembly errors induce velocity differences resulting in high flow velocity portions where ultraviolet light irradiation dose is insufficient

Engineering Contradiction:
Improvesterilization consistencyVSAvoidassembly error sensitivity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The flow straightening chamber is designed to pre-condition the fluid flow before it enters the processing flow path. By establishing a controlled flow regime in advance through the chamber's geometry and flow straightening members, the system compensates for assembly variations in the gaps, ensuring consistent flow velocity and adequate ultraviolet light irradiation throughout the processing section.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flow straightening chamber acts as an intermediary component between the inlet and the processing flow path. It mediates the flow characteristics by reducing turbulence and velocity variations, thereby decoupling the sensitivity to assembly errors from the final sterilization effectiveness in the processing section.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the gaps are made large to prevent velocity differences from assembly errors, then assembly error sensitivity is reduced, but velocity difference due to fluid inertia cannot be sufficiently reduced

Engineering Contradiction:
Improvesterilization consistencyVSAvoidflow velocity control
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The system is divided into distinct functional sections: a flow straightening chamber for flow conditioning and a processing flow path for sterilization. This segmentation allows the gaps in the processing section to be optimized for their primary function while the flow straightening chamber handles flow velocity control, resolving the contradiction between gap size and flow velocity uniformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the device have different structural characteristics optimized for their specific functions. The flow straightening chamber contains flow control features (facing members, gaps) optimized for velocity uniformity, while the processing flow path has larger gaps optimized for maintaining laminar flow and reducing assembly error sensitivity. This local optimization resolves the contradiction.

Inventive Principle:
Principle #3Local quality

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 effectively suppresses variations in ultraviolet light dosages applied to the fluid, ensuring consistent sterilization across the flow path while reducing biofilm formation and enhancing the reliability of the sterilization process.

Implementation Method 1

use, as an ultraviolet light source, light emitting diode (s) (LEDs) capable of applying light with sterilizable wavelength

Methodology Applied
Scientific EffectLight emitting diode (LED): Light Emitting Diode

Implementation Method 2

it is preferable to form a flow velocity distribution matching with a light flux distribution of ultraviolet light in a sterilization region

Methodology Applied
Scientific EffectFlow velocity distribution:

Implementation Method 3

when pressure loss is set to be large, i.e., the gaps are made small

Methodology Applied
Scientific EffectPressure loss: Pressure Drop

Data Source

PatentEP3578207B1Ultraviolet light irradiation device
Publication Date: 2024.06.19 ASAHI KASEI KOGYO KABUSHIKI KAISHA
  • EP3578207B1 patent drawingFigure 1
  • EP3578207B1 patent drawingFigure 2A~2B
  • EP3578207B1 patent drawingFigure 3~4

AI summary

Provided is a fluid sterilization module capable of suppressing variation in ultraviolet light irradiation dose caused by a high flow velocity portion formed in a fluid flowing through a flow path due to an assembly error. To this end, a fluid sterilization module (1) includes an inner cylinder (21) forming a cylindrical processing flow path (21d) extending in a longitudinal direction, a first chamber (26) communicating with the processing flow path (21d) via an opening on one end side of the inner cylinder (21), an inflow portion (4) allowing an object to flow in the first chamber (26), an outflow portion (5) allowing the object having passed through the processing flow path (21d) to flow out from an other end side of the inner cylinder (21), and a light emitting element (34a) provided facing an opening on the other end side of the processing flow path (21d) and configured to irradiate the object passing through the processing flow path (21d) with ultraviolet light along the longitudinal direction. The first chamber (26) has an inner volume equal to or more than 2/3 of the cube of an equivalent inner diameter of the processing flow path (21d) and equal to or less than 3 times of inner volume of the processing flow path (21d).