Venturi Bubble Lighting for Algae Bioreactors
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Solution Overview
Problem
Existing algae cultivation systems face inefficiencies in light penetration and excess heat issues due to submerged light sources, which limit design flexibility and increase costs, especially in bioreactors where sunlight penetration is limited and multiple light sources are required to achieve uniform lighting.
Innovation Solution
The method involves injecting a stream of bubbles into the liquid to allow light from an external source to penetrate deep into the liquid, using a narrow beam angle to concentrate light within the bubble stream, and varying bubble injection to control light penetration depth, with the light source positioned outside the liquid and optionally protected by a waterproof transparent housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple submerged light sources are used to distribute light uniformly throughout the water, then light distribution is improved, but excess heat transferred to the water increases
Solution Approach 1:
The light source is extracted from the water and positioned externally. The patent uses a transparent tube or column structure that allows light to pass through while keeping the light source outside the liquid medium, thereby eliminating direct heat transfer to the water while maintaining uniform light distribution through the tube.
Solution Approach 2:
A transparent tube or column acts as an intermediary between the external light source and the water. This mediator allows light transmission while providing thermal isolation, enabling uniform light distribution without transferring excess heat to the cultured organisms.
2Illumination intensity
If multiple submerged light sources are used to distribute light uniformly, then light penetration is improved, but device complexity and cost increase
Solution Approach 1:
The system segments the light distribution function into a transparent tube structure that can be divided into multiple sections or columns. Each segment independently distributes light, allowing modular scaling without requiring complex control systems for multiple discrete light sources.
Solution Approach 2:
The transparent tube serves multiple functions simultaneously: it acts as a light guide, a structural support, and a containment element. This multi-functionality reduces the need for additional specialized components, simplifying the overall device design while achieving uniform light penetration.
3Illumination intensity
If submerged light sources are used, then light distribution is improved, but space in the liquid is occupied limiting design flexibility
Solution Approach 1:
The light source is extracted from the liquid medium and positioned externally, freeing up space within the bioreactor for other components and organism growth. The transparent tube extends into the liquid to provide light distribution without occupying valuable growth space.
Solution Approach 2:
The light distribution system transitions from a horizontal arrangement of multiple light sources to a vertical transparent tube structure. This dimensional change allows light to be distributed uniformly throughout the water column without occupying horizontal space, enabling greater design flexibility in bioreactor configuration.
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 approach enables efficient and uniform light distribution throughout the liquid, reducing excess heat and allowing for more flexible and cost-effective bioreactor designs by using external light sources, while maintaining effective algae growth and filtration capabilities.
Implementation Method 1
The bubbles allow some light to travel deep into the liquid along the length of the bubble stream and also scatter/deflect some light out of the bubble stream and into the surrounding liquid
Implementation Method 2
The venturi effect can be exerted in a low/negative pressure area (e.g., before the intake of a water skimmer pump) or in a high/positive pressure area (e.g., after the outtake of a water pump)
Data Source
AI summary
A water filtering system includes providing light deep into a liquid used in applications such as the cultivation of both attached and suspended photosynthetic organisms. The system is configured to inject a stream of bubbles into the liquid and a light source is configured to shines light through the bubbles. The bubbles allow some light to travel deep into the liquid along the length of the bubble stream and scatter/deflect some light out of the bubble stream and into the surrounding liquid including screens for growing algae.