Thermoplastic Container Venting for Exothermic Decomposition Safety

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Solution Overview

Problem

The storage and transportation of organic peroxides and other compounds liable to exothermic decomposition are hazardous due to the risk of violent explosions from gas buildup, especially in larger containers where heat dissipation is impaired, leading to unsafe conditions.

Innovation Solution

Using large volume plastic containers with a vent and made from thermoplastic materials with a Vicat B softening temperature below the run-away temperature of the compound, allowing the container walls to soften and release gases gently without explosive rupture, thereby ensuring safety during exothermic decomposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If large volume containers are used for storage and transport of peroxides, then transportation efficiency and storage capacity are improved, but the surface-to-volume ratio decreases making heat dissipation more difficult and increasing explosion hazard

Engineering Contradiction:
Improvecontainer volumeVSAvoidexplosion hazard
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by incorporating a vent into the container design before any decomposition event occurs. This vent is specifically configured to activate at a predetermined temperature threshold, allowing decomposition gases to escape before pressure buildup can lead to explosive rupture. The container is pre-prepared with pressure relief capabilities that automatically engage when thermal decomposition begins, preventing the harmful effect of explosion while maintaining large volume capacity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes phase transitions by designing the container with a thermoplastic material having a specific Vicat B softening temperature below the run-away temperature of the peroxide compound. When decomposition heat raises the container temperature to the softening point, the plastic walls transition from rigid to soft state, causing the container to collapse or tear and release gases. This controlled phase transition of the container material serves as a safety mechanism that prevents explosive rupture while accommodating large volumes.

Inventive Principle:
Principle #36Phase transitions

2Strength

If steel containers are used to withstand explosion pressures, then container strength is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecontainer strengthVSAvoidcontainer complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by selecting a thermoplastic material with a specific Vicat B softening temperature parameter that is below the run-away temperature of the peroxide compound. This parameter selection allows the container to maintain sufficient strength for normal storage and transport conditions while automatically failing safely when decomposition occurs. The plastic material's temperature-dependent mechanical properties enable the container to transition from a strong, rigid state during normal use to a soft, collapsible state during decomposition, replacing complex steel constructions with simpler plastic designs.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If aqueous diluents are used to improve heat dissipation, then safety is improved, but applicability for certain polymerization reactions is reduced

Engineering Contradiction:
ImprovesafetyVSAvoidpolymerization applicability
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent converts the potentially harmful effect of decomposition heat into a beneficial safety mechanism. Instead of relying on aqueous diluents to passively absorb heat, the invention uses the decomposition heat itself to trigger the softening of the thermoplastic container walls. The heat that would otherwise lead to pressure buildup and explosion is instead utilized to activate the pressure relief mechanism through temperature-dependent material softening, thereby converting a harmful thermal effect into a beneficial safety response.

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

Solution Approach 2:

The thermoplastic container material acts as an intermediary between the peroxide compound and the external environment. Rather than using aqueous diluents as intermediaries for heat transfer, the container walls themselves serve as the intermediary medium. The thermoplastic material mediates the thermal energy from decomposition by undergoing softening at a controlled temperature, thereby transferring the decomposition effect into a safe pressure relief mechanism without requiring water-based dilution that would limit chemical applicability.

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

The solution effectively prevents explosive rupture of containers during exothermic decomposition by allowing controlled release of gases and liquids, enhancing safety in storage and transportation of hazardous compounds.

Implementation Method 1

If the temperature within the container rises due to exothermic decomposition, (parts of) the walls of the container can soften and decrease in strength before the build-up of gases becomes dangerously high

Methodology Applied
Scientific EffectThermal softening: Melting

Implementation Method 2

provided with a vent to release gases

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Implementation Method 3

This softening will result in the container to collapse and/or one or more container walls to tear, thereby releasing gas and/or liquid in a gentle way

Methodology Applied
Scientific EffectStructural deformation: Deformation

Data Source

PatentEP2297210B2Packaged formulation comprising a compound liable to exothermic decomposition
Publication Date: 2020.11.18 AKZO NOBEL CHEMICALS INTERNATIONAL BV

AI summary

Packaged formulation comprising a compound liable to exothermic decomposition and optionally one or more organic diluents, said formulation being packaged in a container with a volume of at least 250 litre provided with a vent to release gases and made from a thermoplastic material having a Vicat B softening temperature not higher than (a) the run-away temperature of the compound liable to exothermic decomposition if the formulation does not contain any diluent, or (b) the boiling temperature of at least 50 wt% of the total weight of diluent if the formulation does contain organic diluent.