Internally Illuminated Bioreactor With Passive LED Heat Removal
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Solution Overview
Problem
Current bioreactor systems for algae production are limited by their inability to scale industrially due to insufficient lighting penetration, heat management issues with internal lighting, and complex cooling systems, which hinder consistent and efficient production.
Innovation Solution
An internally illuminated bioreactor with in-water grow lights using LED chips and a heat management system that dissipates heat through forced air without mechanical air handling devices, combined with an automated cleaning system to maintain continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If external grow lights are used to illuminate the bioreactor, then the lighting setup is simple, but light cannot penetrate through denser cultures and the bioreactor size is limited
Solution Approach 1:
Instead of placing grow lights outside the bioreactor to illuminate the culture, the patent inverts the approach by submerging the grow lights directly into the culture. This allows light to be emitted from within the culture, enabling penetration through denser algal suspensions that would otherwise block external light.
Solution Approach 2:
The patent transitions from two-dimensional external illumination (lights around the perimeter) to three-dimensional internal illumination (lights distributed throughout the culture volume). This allows light to reach algae in the interior regions of the bioreactor from multiple directions, overcoming the limitation of external lighting.
2Illumination intensity
If internal lighting fixtures are used to illuminate the bioreactor, then light penetration is improved, but heat generation adversely affects the culture and requires complex cooling systems
Solution Approach 1:
The patent extracts the harmful heat generated by internal grow lights by routing it through a separate heat exchange system. The housing contains channels that allow culture fluid to flow past the light sources, carrying heat away from the sensitive algal culture while maintaining effective illumination.
Solution Approach 2:
The patent introduces culture fluid as an intermediary medium to transfer heat from the grow lights to the surrounding environment. The fluid flows through heat exchange channels, absorbing excess heat from the lights and dissipating it, thereby protecting the culture from thermal damage.
3Productivity
If large bioreactors are used to increase production capacity, then industrial scale requirements are met, but light penetration to interior regions becomes insufficient
Solution Approach 1:
The patent segments the illumination function by distributing multiple grow light fixtures throughout the bioreactor volume rather than relying on a single external light source. This allows large bioreactors to receive adequate light penetration from multiple internal sources positioned at different locations.
Solution Approach 2:
The patent transitions from perimeter-based lighting (2D) to volumetric lighting (3D), allowing light to reach interior regions of large bioreactors from multiple directions and depths, ensuring uniform illumination throughout the entire culture volume.
4Illumination intensity
If regular cleaning is performed to maintain bioreactor performance, then light transmission is maintained, but production must be interrupted
Solution Approach 1:
The patent implements continuous cleaning action through automated wipers that operate while the bioreactor is running. This maintains light transmission through the culture without requiring production interruptions, as the cleaning mechanism functions continuously alongside the algae cultivation process.
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 system enables efficient and scalable algae production by ensuring uniform lighting and effective heat dissipation, allowing continuous operation with minimal maintenance, thus meeting industrial-scale demands.
Implementation Method 1
a plurality of lighting elements positioned around a perimeter of the interior tube so as to project light into the growth chamber to stimulate growth of algae in the growth chamber
Implementation Method 2
Forced air may be supplied to the interior tube, such that the air flow removes heat from the lighting elements
Implementation Method 3
the air flow is warmed as it travels through the interior tube, such that the heat is carried away from the lighting elements. The air flow may then travel upwards between the lighting elements and the exterior tube through buoyancy of the warmed air
Data Source
AI summary
Disclosed is an internally illuminated bioreactor, and related algae production methods, that employ integrated in-water grow light assemblies configured to manage the heat generated by lighting elements, such as light emitting diodes (“LEDs”) on the in-water grow lights. The bioreactor includes an outer shell and one or more in-water grow light fixtures positioned within the outer shell that are positioned around the perimeter of a hollow, internal tube. The lighting elements and internal tube are themselves contained within a preferably clear, exterior tube of the light fixture that allows light generated by the lighting elements to pass through to the algae culture inside of the growth chamber. A heat management system is provided for cooling the light fixture using forced directed through the hollow, internal tube from the top to the bottom of the tube, out from outlets at the bottom of the internal tube, and upward in the fixture through buoyancy of the warmed air, and thus without additional mechanical air handling devices. As the air moves upward between the lighting elements and the exterior tube, it draws additional heat away from the lighting elements. The warmed air is ultimately exhausted from the top of the lighting fixture. Each lighting fixture preferably also includes a cleaning system that enables the automated cleaning of the outer surface of the exterior tube of the lighting fixture, thus preventing newly formed algae from collecting on the lighting fixture and ensuring a continuous flow of light from the fixture into the algae culture throughout algae production.