LED Irradiation for Killing Marine Larvae in Coolant Systems

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Solution Overview

Problem

Existing methods for preventing the settlement of marine invertebrates in power plant coolant systems are inadequate in effectively killing larvae of sessile invertebrates, leading to potential clogging issues.

Innovation Solution

Irradiating larvae with an LED beam in the spectrum of 409 to 412 nm, with a peak intensity of 146.4643 μWcm−2nm−1 or higher, for 3 hours or more to stop their activity and ultimately kill them, which is effective for both mussel and barnacle larvae.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chlorine-based substances are injected into the coolant to suppress settlement of marine invertebrates, then the settlement of barnacles and mussels is suppressed, but harmful chemical substances are introduced into the seawater environment

Engineering Contradiction:
Improvesuppression of marine invertebrate settlementVSAvoidchemical pollution of seawater
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces chemical methods (chlorine-based substances) with a physical method (light irradiation using LEDs emitting 409-412 nm wavelengths) to kill marine invertebrate larvae. This substitution eliminates chemical pollution while maintaining effective larvicidal activity, directly resolving the contradiction between settlement suppression and environmental protection

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

Solution Approach 2:

The patent changes the parameter of light wavelength to specifically 409-412 nm range, which has been shown to be most effective for killing marine invertebrate larvae. By optimizing this specific parameter, the method achieves high efficacy with physical light energy alone, avoiding the need for chemical substances and their associated environmental harm

Inventive Principle:
Principle #35Parameter changes

2Reliability

If photocatalysts or laser beams are used to kill larvae, then settlement suppression is achieved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvelarval mortality rateVSAvoidcomplexity of light irradiation system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs standard LED components that are inexpensive, commercially available, and have sufficient operational lifespan for the application. These LEDs emitting 409-412 nm wavelengths can be easily replaced if needed, providing a cost-effective and simple solution that avoids the complexity of photocatalyst systems or high-power laser equipment

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent uses standard LED technology that can be easily integrated into existing power plant cooling systems. The LEDs serve multiple functions: they emit the specific wavelength needed for larvicidal activity, they are energy-efficient, and they can be positioned flexibly within the water flow path, making the system adaptable and simple to implement

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

3Reliability

If high intensity light irradiation is applied to kill larvae, then killing effectiveness is improved, but energy consumption increases

Engineering Contradiction:
Improvelarval mortality rateVSAvoidenergy consumption of LED irradiation system
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent optimizes the light wavelength parameter to 409-412 nm, which corresponds to the absorption peak of chromophores in marine invertebrate larvae. This parameter optimization maximizes the biological effectiveness per unit of energy input, achieving high larval mortality rates with relatively low energy consumption compared to broader spectrum or higher intensity sources

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies light irradiation at intensities and durations that are sufficient to achieve complete larval mortality but not excessively high. By using multiple LEDs distributed throughout the water flow path, the system delivers adequate cumulative energy exposure to larvae over time, achieving effective killing without requiring extremely high instantaneous power that would waste energy

Inventive Principle:
Principle #16Partial or excessive action

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 method effectively prevents the settlement of mussel and barnacle larvae by weakening and killing them, demonstrating a significant improvement over other wavelength-based methods, with LED irradiation being particularly effective in seawater environments.

Implementation Method 1

irradiating light including the spectrum of 409 to 412 nm, to the larva in the settlement stage

Methodology Applied
Scientific EffectLight irradiation effect: Light

Implementation Method 2

The light may be an LED beam

Methodology Applied
Scientific EffectLED emission: Light Emitting Diode

Data Source

PatentUS11134669B2Method for killing Pteriomorphia and barnacles using light irradiation
Publication Date: 2021.10.05 THE CHUGOKU ELECTRIC POWER CO INC

AI summary

The present invention provides a method of killing larvae of sessile invertebrates in the settlement stage in water, comprising the step of irradiating light comprising the spectrum of 409 to 412 nm, to the larvae in the settlement stage.