Stabilized Foam Decontamination Using Solid Particles

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Solution Overview

Problem

Existing decontamination, stripping, and degreasing technologies face challenges in achieving prolonged contact times, reducing surfactant and gelling agent quantities, and efficiently treating surfaces with complex geometries or high radioactivity, while minimizing effluent production.

Innovation Solution

A stabilized foam comprising a dispersion of air bubbles in a liquid with a solid stabilizing agent, such as solid particles, which reduces the need for surfactants and gelling agents, enhances foam stability, and allows for prolonged contact with surfaces, capturing chemical entities and reducing effluent volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional foaming solutions are used with high surfactant and gelling agent content, then foam volume and initial stability are improved, but the quantity of chemical substances increases and environmental impact worsens

Engineering Contradiction:
Improvefoam stabilityVSAvoidquantity of surfactant and gelling agent
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The invention changes the chemical composition parameters of the foam by replacing conventional organic gelling agents with inorganic gel-forming substances (such as silicates, aluminosilicates, or zeolites) and reducing surfactant content to 0.01-5% by weight. This parameter change maintains foam stability while significantly reducing the quantity and environmental impact of chemical substances used.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite foam system combining inorganic gel-forming substances with surfactants. The inorganic particles form a three-dimensional gel network that works synergistically with reduced surfactant amounts to maintain foam stability. This composite approach allows using minimal chemical substances while achieving the required foam properties.

Inventive Principle:
Principle #40Composite materials

2Duration of action of moving object

If foam lifespan is extended through conventional means, then contact time with surface is improved, but foam stability and resistance to drainage increase requiring more stabilizing agents

Engineering Contradiction:
Improvefoam lifespanVSAvoidquantity of stabilizing agents
Core Design Contradiction:
Duration of action of moving objectVSQuantity of substance

Solution Approach 1:

The invention extends foam lifespan by changing the physical-chemical parameters of the foam structure through inorganic gel particles. These particles modify the liquid film properties and bubble wall characteristics, reducing drainage rate and extending foam life to several hours without requiring high concentrations of conventional organic stabilizing agents.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces organic polymer-based foam stabilizing mechanisms with inorganic gel network formation. The inorganic particles create a structural framework through gelation that mechanically supports the foam structure, providing long-term stability without relying on large amounts of organic surfactants or polymers.

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

3Loss of substance

If effluent volume is reduced through foam application, then water consumption is improved, but treatment complexity and solid particle separation difficulty increase

Engineering Contradiction:
Improveeffluent volumeVSAvoidtreatment process complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The invention changes the physical properties of the foam and resulting effluent by using inorganic gel particles instead of organic gelling agents. The inorganic particles settle more readily and form easier-to-handle sludge, simplifying separation and treatment processes while maintaining reduced effluent volume benefits.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses inexpensive inorganic gel-forming substances (such as common silicates or aluminosilicates) that can be easily disposed of or regenerated after use. These materials are more readily separable from effluent than organic polymers, reducing treatment complexity despite the benefit of minimized effluent volume.

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

Data Source

PatentEP2126023B1Decontamination, stripping and/or degreasing foam containing solid particles
Publication Date: 2014.08.27 AREVA NC
  • EP2126023B1 patent drawingFigure 1
  • EP2126023B1 patent drawingFigure 2
  • EP2126023B1 patent drawingFigure 3

AI summary

The present invention relates to a stabilized foam that comprises a foaming aqueous solution containing from 0.1 to 7 moles of one or more decontamination, stripping and/or degreasing reagents per litre of solution, and from 0.01 to 15 wt % of a solid stabilising agent of the solid-particle type relative to the total weight of the solution. The invention also relates to a method for preparing said stabilised foam, to the use thereof for decontaminating, stripping and/or degreasing a surface, and to a method for decontaminating, stripping and/or degreasing a surface.