Gas Generator Obstacle Grid Prevents Powder Ejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas generators for motor vehicle safety systems face a risk of the secondary pyrotechnic compound being ejected through gas discharge orifices before complete decomposition, leading to incomplete combustion and potential safety hazards.
Innovation Solution
A gas generator design featuring a central nozzle connecting the primary and secondary chambers, with a grid or perforated plate obstacle in the secondary chamber that allows gas passage into a central part while blocking it in a peripheral part, maintaining a slightly confined interaction volume and preventing powder ejection, and utilizing a secondary compound like ammonium nitrate with a reducing additive for efficient combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the secondary compound is contained in a second zone with orifices for discharging gases, then the gas generation efficiency is improved, but the risk of powder ejection through orifices increases
Solution Approach 1:
The second chamber is divided into a first zone for gas interaction and a second zone for secondary compound storage, with a grid structure separating them. This segmentation allows gases to be generated efficiently in the first zone while the grid prevents powder from reaching the orifices in the second zone.
Solution Approach 2:
A grid structure is introduced as an intermediary element between the gas interaction zone and the secondary compound storage zone. The grid allows gases to pass through while blocking powder particles, thus mediating between the need for efficient gas discharge and the need to prevent powder ejection.
2Reliability
If the interaction volume is highly confined to prevent powder ejection, then the safety is improved, but the combustion efficiency decreases
Solution Approach 1:
Different zones within the second chamber have different confinement characteristics. The first zone has moderate confinement to maintain combustion efficiency, while the grid in the second zone provides local containment to prevent powder ejection, creating locally optimized conditions in each zone.
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
Ensures complete combustion of the secondary compound within the generator, preventing powder ejection and maintaining a stable, slightly confined interaction volume for efficient gas generation, thereby enhancing safety and reliability.
Implementation Method 1
the products of combustion of the primary pyrotechnic compound entail the decomposition of a secondary compound
Implementation Method 2
the products of combustion of the primary compound and those of the secondary compound interact through an oxidation-reduction reaction in a slightly confined volume
Implementation Method 3
an interaction of the products of combustion of the primary compound and those of the secondary compound occurs through an oxidation-reduction reaction in a slightly confined volume
Data Source
AI summary
A gas generator for a safety system includes an explosible charge formed at least by a primary pyrotechnic compound, in a first chamber initiated by at least one initiator provided with a reinforcing charge and a secondary compound, in a second chamber, the decomposition of which is entailed by products of combustion of the primary compound, an interaction of the products of combustion of the primary compound and those of the secondary compound through an oxidation-reduction reaction occurring in a slightly confined volume, the first chamber communicating with said second chamber through a central nozzle and said second chamber being provided, at a first zone close to said first chamber, with orifices that discharge the gases and contain, in a second zone, said secondary compound; and means forming an obstacle to the passage of the gases installed in said second chamber between said first and second zones, said obstacle-forming means allowing the gases to pass into a central part and forming an obstacle to their passage into a peripheral part with sufficient transparency for the gas interaction volume to be slightly confined.