Air Bag Inflator Inerting via Controlled Ignition and Water Shredding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods are inadequate for efficiently rendering large quantities of air bag inflators and other low-level detonatable devices inert for recycling, posing risks during scrapping and recycling processes due to potential explosions and inadequate separation of chemical constituents from metal or plastics.

Innovation Solution

A continuous shredding process within a special chamber filled with water, using a low-speed dual stacked hydraulic shredder system and water irrigation to hydrolyze chemical constituents, followed by dewatering and optional high-temperature processing to render materials inert, allowing for safe recycling of metal components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional scrapping methods are used on air bag inflators, then the scrapping process can be performed, but there is a risk of explosion due to unused air bag units being compressed

Engineering Contradiction:

Improvescrapping efficiencyVSAvoidsafety during scrapping

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary action by automatically detecting air bag inflators and rendering them inert through controlled ignition before the scrapping process begins. This prevents the safety issue of explosions during compression while maintaining scrapping efficiency, as the inflators are neutralized in advance of the actual scrapping operation.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If manual processing methods are used for air bag inflators, then small numbers can be processed, but large quantities cannot be efficiently rendered inert for recycling

Engineering Contradiction:

Improvesafe destructionVSAvoidprocessing capacity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system replaces manual mechanical processing with an automated controlled ignition system. The controlled ignition apparatus automatically detects inflators and applies precise electrical signals to ignite the propellant in a controlled manner, eliminating the need for manual handling while safely processing large quantities of inflators for recycling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If air bag inflators are compressed during scrapping, then the scrapping process can proceed, but the chemical propellant may detonate causing explosions

Engineering Contradiction:

Improvescrapping process simplicityVSAvoidexplosion risk

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The system converts the potentially harmful explosive propellant into a beneficial controlled reaction. By using controlled ignition to deliberately and safely burn off the propellant before scrapping, the system transforms the explosion risk into a controlled energy release that neutralizes the hazard while maintaining the simplicity of the overall scrapping process.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Productivity

If chemical constituents are not separated from metal components, then recycling can proceed quickly, but proper recycling cannot be achieved

Engineering Contradiction:

Improverecycling speedVSAvoidseparation quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system extracts and removes the chemical propellant constituents from the metal housing through controlled ignition and burning. This separation process removes the hazardous chemicals while leaving the metal components intact and ready for recycling, achieving both proper separation quality and recycling efficiency by eliminating the need for complex chemical separation processes.

Inventive Principle:

Principle #2Taking out (Extraction)

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 process effectively renders air bag inflators and other combustible materials inert, enabling safe and efficient recycling of large quantities by preventing explosions and ensuring proper separation of hazardous chemicals from metal scraps, with the system capable of processing up to 80,000 to 180,000 pounds per day.

Implementation Method 1

water irrigation to hydrolyze chemical constituents

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

A continuous shredding process within a special chamber filled with water

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

optional high-temperature processing to render materials inert

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentUS10710095B2Apparatus and method to render air bag inflators and other low level detonatable devices inert for recycling

Publication Date: 2020.07.14 CLEAN HARBORS ENVIRONMENTAL SERVICES

AI summary

Detonable devices such as charged air bag inflators are fed to a shred tower at a controlled feed rate via a feed valve. Water spray and/or water baths in the shred tower prevent sparking and begin to solubilize chemicals while the inflators are fed to primary and optional secondary shredders respectively performing course and fine shreds. A sump receives the shredded material which continues solubilize and separate chemicals from metal. A conveyor lifts solids from the sump. Dewatered solids are fed to a receiving box for metal scrap recycling.