Liquid Processing Apparatus Gas Phase Plasma Generation

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Solution Overview

Problem

Existing liquid processing apparatuses face inefficiencies due to high leakage currents when processing liquids with high electrical conductivity, leading to increased energy usage for heating rather than processing, and unstable plasma generation over time.

Innovation Solution

The apparatus design includes a cylindrical processing tank with a rod-shaped first electrode and a second electrode with a cross-shaped opening portion, where the plasma is generated in a gas phase within the tank, reducing leakage currents by ensuring the plasma comes into contact with both electrodes, and applying a pulse voltage to maintain stable plasma discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If plasma discharge is generated in liquid with high electrical conductivity, then liquid processing function is improved, but leakage current increases causing energy loss for heating

Engineering Contradiction:

Improveliquid processing functionVSAvoidleakage current energy loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent introduces a gas phase as an intermediary medium between the electrodes. Plasma discharge is generated in the gas phase rather than directly in the liquid, which acts as a mediator to transfer the processing effect to the liquid while avoiding direct current leakage through the conductive liquid. This resolves the contradiction by decoupling the plasma generation zone from the liquid contact zone.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If plasma discharge is generated continuously in liquid, then processing efficiency is improved, but plasma stability deteriorates over time

Engineering Contradiction:

Improveprocessing efficiencyVSAvoidplasma generation stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent maintains continuous plasma discharge in the gas phase, which continuously generates reactive species that process the liquid. The gas phase plasma can be sustained continuously without the stability issues that would occur in direct liquid discharge, thereby maintaining both high productivity and plasma stability over extended operation periods.

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If high voltage is applied to generate plasma in liquid, then decomposing and sterilizing action is improved, but temperature of liquid increases

Engineering Contradiction:

Improvedecomposing and sterilizing actionVSAvoidliquid temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The gas phase serves as an intermediary that absorbs the energy of high voltage plasma discharge and transfers only the chemical processing effects (decomposing and sterilizing actions) to the liquid, while preventing direct thermal energy transfer. This allows high voltage application for effective processing without significant liquid temperature increase.

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

This configuration enhances energy efficiency by minimizing leakage currents, allowing for stable plasma generation and efficient processing of liquids over extended periods without temperature rises, ensuring continuous operation.

Implementation Method 1

the plasma discharge is generated in gas phase G by applying a high voltage between first electrode 130 and second electrode 131

Methodology Applied

Scientific EffectPlasma discharge: Plasma

Implementation Method 2

the decomposing and sterilizing action by ultraviolet light, radicals, or the like generated by plasma discharge

Methodology Applied

Scientific EffectUltraviolet light generation:

Implementation Method 3

components having oxidizing power such as hydroxyl radical (OH radical) and hydrogen peroxide are generated and the decomposition process progresses

Methodology Applied

Scientific EffectRadical generation:

Implementation Method 4

water vapor is generated by vaporizing a part of liquid L1 in the vicinity of central axis X1 and thereby gas phase G is generated

Methodology Applied

Scientific EffectVaporization: Evaporation

Implementation Method 5

liquid L1 is introduced from introduction portion 115 provided in a tangential direction of cylindrical processing tank 112 to generate swirling flow F1

Methodology Applied

Scientific EffectSwirling flow: Turbulence

Implementation Method 6

plasma discharge is generated in gas phase G by applying a high voltage between first electrode 130 and second electrode 131

Methodology Applied

Scientific EffectPlasma generation: Plasma

Data Source

PatentUS10934183B2Liquid processing apparatus

Publication Date: 2021.03.02 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A liquid processing apparatus includes a processing tank, a liquid introduction port, a discharge portion, a first electrode, a second electrode, and a power supply. The liquid introduction port is disposed on a first end side of the processing tank, causes a liquid to swirl in the processing tank by introducing the liquid into the processing tank in a tangential direction of the processing tank, and generates a gas phase in a swirling flow of the liquid. The first electrode has a rod shape and is disposed at the first end on a central axis of the processing tank. The second electrode is disposed so as to be exposed to the discharge portion of the processing tank. A voltage is applied between the first electrode and the second electrode to generate plasma in the gas phase.