UV LED Reflector Layout for Uniform Pipe Liner Curing

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Solution Overview

Problem

Existing devices for curing plastic hoses impregnated with UV-curing synthetic resin in sewer pipes face issues with uneven and unreliable irradiation due to the failure of UV light-emitting diodes, and the use of vacuum tube-based UV lamps is inefficient and costly.

Innovation Solution

A device with light-emitting diodes aligned parallel to the housing axis, reflecting UV radiation radially to ensure uniform irradiation, using multiple circuit boards for increased power and cooling, and incorporating reflectors and fans for effective radiation distribution and cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If UV-emitting LEDs are mounted on the outer wall of the housing to achieve uniform irradiation, then the irradiation uniformity is improved, but the device complexity and manufacturing difficulty increase due to the need for precise even distribution

Engineering Contradiction:
Improveirradiation uniformityVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent changes the mounting dimension of LEDs from the outer wall surface (2D distribution) to the end face surface (2D distribution but different orientation). By mounting LEDs on the end face with their emission directions parallel to the housing axis, the reflector can then redirect the light radially, achieving uniform irradiation through a different spatial arrangement that simplifies manufacturing.

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

2Temperature

If LEDs are mounted on the end face of a cylindrical body to ensure cooling, then the cooling effectiveness is improved, but the installation space requirement increases significantly

Engineering Contradiction:
Improvecooling effectivenessVSAvoidinstallation space
Core Design Contradiction:
TemperatureVSVolume of stationary object

Solution Approach 1:

The end face of the cylindrical housing serves multiple functions: it provides the mounting surface for LEDs, acts as a support structure for the circuit board, and maintains the structural integrity of the housing. This multi-functionality eliminates the need for separate cooling structures, reducing overall installation space while ensuring effective cooling through the housing wall.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If vacuum tube-based UV lamps are used for curing, then the curing capability is achieved, but the reliability decreases and energy consumption increases

Engineering Contradiction:
Improvecuring capabilityVSAvoidreliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces the mechanical vacuum tube UV lamp system with a solid-state LED-based UV light source. LEDs are more reliable as they have no fragile glass envelopes or vacuum seals, consume less energy, and have longer operational lifetimes while maintaining the necessary UV curing capability for the plastic liner.

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

4Productivity

If LEDs are oriented with emission direction perpendicular to the housing axis to strike the tube directly, then the curing efficiency is improved, but the irradiation uniformity deteriorates due to limited effectively irradiated area

Engineering Contradiction:
Improvecuring efficiencyVSAvoidirradiation uniformity
Core Design Contradiction:
ProductivityVSIllumination intensity

Solution Approach 1:

The patent introduces a reflector as an intermediary element between the LEDs and the plastic tube. The reflector redirects the UV radiation from the axially-oriented LEDs radially outward, ensuring uniform distribution of light across the tube surface. This intermediary component enables both high curing efficiency and uniform irradiation simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides error-free, uniform, and efficient curing of plastic hoses with reduced energy consumption and space requirements, ensuring consistent irradiation even if individual diodes fail, and effective cooling of the light-emitting diodes.

Implementation Method 1

at least one UV-emitting light source, wherein the light source is formed by several UV-emitting LEDs

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

Implementation Method 2

the emitted UV radiation striking at least one reflector which reflects the emitted UV radiation radially to the longitudinal axis of the housing

Methodology Applied
Scientific EffectUV radiation reflection: Reflection

Implementation Method 3

a fan (13) which generates a cooling airflow (14) for cooling the light-emitting diodes (5)

Methodology Applied
Scientific EffectForced convection cooling: Forced Convection

Implementation Method 4

Heat sinks (16) arranged on the back of the light-emitting diodes (5) to cool the light source (3)

Methodology Applied
Scientific EffectHeat sink thermal conduction: Conduction (thermal)

Data Source

PatentEP3821163B1LED UV device and system for pipe rehabilitation
Publication Date: 2023.09.06 TRELLEBORG SEALING PROFILES GERMANY GMBH
  • EP3821163B1 patent drawingFigure 1
  • EP3821163B1 patent drawingFigure 2
  • EP3821163B1 patent drawingFigure 3

AI summary

The invention relates to a device (1) for curing a plastic tube (100), which is impregnated with UV-curing synthetic resin, in a sewage pipe (101), the device comprising an elongate housing (2), the longitudinal axis of which runs in the processing direction (102) along the sewage pipe (100), and at least one light source (3) which emits UV radiation, the light source (3) being formed by at least one light emitting diode (5) which emits UV radiation (4), wherein: in the housing (2), the at least one light emitting diode (5) is oriented in the processing direction (102) in such a way that the main emission direction (6) of the UV radiation emitted by the light emitting diode (5) is oriented substantially parallel to the longitudinal axis of the housing (2); the emitted UV radiation (4) hits at least one reflector (7, 8), which reflects the emitted UV radiation (4) radially with respect to the longitudinal axis of the housing (2) such that the emitted UV radiation (4) hits the plastic tube (100) to be curved perpendicularly to the processing direction (102).