Electrode-Based Sterilant Removal via Electric Field Gradient

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Solution Overview

Problem

Existing decontamination systems face challenges in quickly reducing the concentration of vaporous chemical sterilants like VHP to below 1 ppm, as molecules often pass through destroyers without contact and are re-injected, and are adsorbed to surfaces, making it difficult to efficiently remove them from rooms and containers.

Innovation Solution

An apparatus and method using a chemically active and conductive electrode with an electrical charge to create an electrical field gradient, forcing chemical sterilant molecules with induced or permanent dipole moments towards the electrode for removal, reducing re-injection and adsorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a catalytic destroyer is used to reduce VHP concentration, then chemical sterilant molecules are destroyed upon contact with catalytic material, but many VHP molecules pass through the destroyer without contact and are re-injected into the region

Engineering Contradiction:
Improvedecontamination speedVSAvoiddestroyer efficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces an electric field as an intermediary force field between the VHP molecules and the catalytic destroyer. The electric field acts as a mediator to guide and concentrate VHP molecules toward the catalytic surface, increasing contact probability without directly altering the catalytic destruction mechanism. This resolves the contradiction by improving reliability (contact efficiency) while maintaining productivity (decontamination speed).

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical parameter of the VHP molecules by ionizing them or inducing dipole moments through the electric field. This parameter change makes the molecules responsive to electric forces, allowing them to be guided toward the destroyer. The transformation from neutral to polarized/ionized state enables the electric field to exert control over molecule trajectories, improving contact efficiency without sacrificing destruction speed.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If VHP concentration is reduced quickly to below 1 ppm, then human safety is improved, but existing systems require excessive time to achieve this threshold

Engineering Contradiction:
ImproveVHP concentration levelVSAvoidaeration phase duration
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent applies preliminary action by using the electric field to pre-concentrate and guide VHP molecules toward the catalytic destroyer before the actual destruction occurs. This preliminary guidance ensures that molecules are positioned optimally for destruction, accelerating the overall process. By pre-positioning molecules through electric field forces, the system achieves faster concentration reduction without extending the aeration phase.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the passive mechanical diffusion and convection processes with an active electric field-based transport mechanism. Instead of relying on random molecular motion or bulk gas flow to deliver VHP molecules to the destroyer, the electric field provides directed, controllable transport. This substitution dramatically increases the rate at which molecules reach the destruction zone, reducing the time required to achieve safe concentration levels.

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

3Quantity of substance

If VHP molecules are adsorbed to surfaces of walls and articles, then they are removed from the air, but they must first diffuse into the air before circulation through the destroyer

Engineering Contradiction:
ImproveVHP molecules in airVSAvoiddiffusion time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent addresses the surface-to-air transfer problem by introducing a new dimensional approach: applying the electric field directly to surfaces where VHP is adsorbed. Rather than waiting for molecules to diffuse from surfaces into the air bulk, the electric field acts on surfaces to directly desorb and ionize molecules, then immediately guides them into the air stream toward the destroyer. This multi-dimensional approach (surface + air + electric field) eliminates the diffusion bottleneck.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent applies preliminary anti-action by using the electric field to prevent VHP molecules from remaining adsorbed on surfaces. The electric field exerts a force that opposes the adsorption tendency, actively pulling molecules off surfaces and into the gas phase. This preliminary anti-adsorption action occurs continuously, preventing the buildup of surface-bound molecules and maintaining a steady supply of airborne molecules for destruction.

Inventive Principle:
Principle #9Preliminary anti-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

The solution effectively accelerates the removal of chemical sterilant molecules from surfaces and gases, reducing the time required to achieve safe concentration levels and minimizing re-injection, thereby enhancing the efficiency of decontamination processes.

Implementation Method 1

The electrode is connected to a source of an electrical charge such that an electrical field gradient is formed in a region of space surrounding the electrode. The electrical field gradient is operable to force the chemical sterilant molecules toward the electrode.

Methodology Applied
Scientific EffectElectrical field gradient: Electric Field

Implementation Method 2

a method for removing gaseous or vaporous sterilants from a surface wherein the chemical sterilant molecules have an induced electrical dipole moment or a permanent electrical dipole moment

Methodology Applied
Scientific EffectDipole moment interaction: Electrostatic Induction

Data Source

PatentEP2579999B1Method for removing gaseous or vaporous sterilants from a surface
Publication Date: 2019.05.22 STERIS CORP
  • EP2579999B1 patent drawingFigure 1~2
  • EP2579999B1 patent drawingFigure 3~4A
  • EP2579999B1 patent drawingFigure 5~6

AI summary

The present invention provides a method and apparatus for removing chemical sterilant molecules from a medium, such as a carrier gas. In one embodiment, the apparatus includes a housing that defines an internal cavity. The housing has an inlet and an outlet fluidly communicating with the internal cavity. An electrode is dimensioned to be received in the internal cavity of the housing. The electrode is made of a material that is chemically active with respect to molecules of a chemical sterilant and conductive to electricity. The electrode is connected to a source of an electrical charge such that an electrical field gradient is formed in a region of space surrounding the electrode. The electrical field gradient is operable to force the chemical sterilant molecule toward the electrode.