Floating Light Diffuser for Photobioreactor

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Solution Overview

Problem

Current photo-bioreactors for microalgae production face challenges such as high costs, complexity in design, limited scalability, inefficient light concentration, and biofilm clogging, which hinder large-scale production and require significant heat, especially in temperate regions.

Innovation Solution

A device comprising a cylindrical sleeve and a sealed bell with a gas-filled gap, allowing the bell to float and maintain the sleeve submerged, optimizing light distribution, temperature, and circulation while reducing evaporation and biofilm formation, and featuring a reflective surface to enhance light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If closed-circuit basins with flexible sleeves are used to capture and transmit light, then light transmission is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvelight transmissionVSAvoiddevice complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent uses flexible transparent sleeves made of thin film material that can be filled with liquid to maintain cylindrical shape. These flexible shells transmit light effectively while being simpler in structure compared to rigid complex support systems, directly resolving the contradiction between light transmission and device complexity

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The invention employs liquid-filled flexible sleeves where the liquid provides both structural support and light transmission medium. This hydraulic approach simplifies the overall device structure while maintaining effective light transmission to the algal culture

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Illumination intensity

If closed-system technology with sleeves is used, then light distribution is improved, but scalability to large ponds is limited

Engineering Contradiction:
Improvelight distributionVSAvoidscalability
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The system divides the pond into multiple zones with distributed flexible sleeves that can be independently configured. This segmentation allows the same basic technology to be scaled from small to large ponds by simply increasing the number of modular units, resolving the scalability limitation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flexible sleeve design serves multiple functions: light transmission, structural support, and adaptability to different pond sizes. This multi-functionality enables the same technology to be universally applied across various scales from small experimental ponds to large commercial operations

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

3Illumination intensity

If moving lenses are used to focus light towards sleeves, then light concentration is improved, but operational complexity increases

Engineering Contradiction:
Improvelight concentrationVSAvoidoperational complexity
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The flexible sleeves are filled with liquid that automatically adjusts to maintain optimal light transmission without requiring external focusing mechanisms. The system serves itself by using the liquid medium's natural optical properties, eliminating the need for complex moving lenses and dynamic positioning systems

Inventive Principle:
Principle #25Self-service

4Illumination intensity

If sleeves are in contact with algal solution, then light transmission is improved, but biofilm fouling occurs requiring regular cleaning

Engineering Contradiction:
Improvelight transmissionVSAvoidbiofilm fouling
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the light transmission function from the structure directly contacting the algal solution. The flexible sleeves transmit light but are positioned to minimize contact with the algal culture, separating the optical function from the interface that causes biofilm accumulation, thereby reducing fouling while maintaining light transmission

Inventive Principle:
Principle #2Taking out (Extraction)

5Strength

If support structure obscures the free surface, then structural support is provided, but surface area exposed to light is reduced

Engineering Contradiction:
Improvestructural supportVSAvoidsurface area exposed to light
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The flexible support structure is made of thin, transparent film material that provides necessary structural support while being optically transparent. This allows the support to remain strength-sufficient while not obstructing light transmission to the algal culture below, resolving the contradiction between structural support and light exposure area

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution enables efficient light capture and distribution, improving microalgae production, reducing operational costs, and allowing for scalable, autonomous, and versatile operation in various pond sizes and locations, including temperate regions, while minimizing heat requirements and biofilm issues.

Implementation Method 1

a sealed bell, transparent to the light captured, transported and diffused, and formed at least in part by two walls separated by a sealed gap (e) filled in whole or in part by gas, the bell comprising a dome-shaped part extended by a tubular part

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

a cylindrical sleeve, made of material transparent to the transported and diffused light, the sleeve being intended to be filled with a liquid suitable for transmitting and diffusing light and for balancing the external pressure to maintain the sleeve in cylindrical form

Methodology Applied
Scientific EffectLight transmission and diffusion: Diffusion

Implementation Method 3

filled with a liquid suitable for transmitting and diffusing light and for balancing the external pressure to maintain the sleeve in cylindrical form

Methodology Applied
Scientific EffectPressure balance: Pascal's Law

Implementation Method 4

featuring a reflective surface to enhance light transmission

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3647406B1Device for capture, transport and light diffusion for a photobioreactor
Publication Date: 2021.06.23 NENUPHAR
  • EP3647406B1 patent drawingFigure 1~3
  • EP3647406B1 patent drawingFigure 4~6
  • EP3647406B1 patent drawingFigure 7~9

AI summary

The invention provides a device (100) for transporting and diffusing light in a solution (1) contained in a reservoir (2), which is simple to implement, efficient, limits water evaporation from the basin, is self-contained, economical, and versatile. The device comprises a transparent cylindrical sleeve (110) intended to be filled with a liquid suitable for transmitting and diffusing light, and a sealed, transparent bell (120) formed, at least in part, by two walls (120a-120b) separated by a sealed gap (e) filled wholly or partly with gas. The bell comprises a domed portion (121) extended by a tubular portion (122). A first end (111) of the sleeve (110) is intended to be secured against the bell (120) so that, in the operating position, the bell floats freely in the solution and keeps at least the domed portion (121) above water, while ensuring the verticality of the sleeve (110).