Nested Metallic Mixture Blasting Capsule for Reliable Spark Ignition
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Solution Overview
Problem
Conventional rapidly expanding metallic mixtures face difficulties in initiating the oxidation reaction, especially due to surface oxidation of metal powders when exposed to moisture or oxygen, and interference from additives like oil or inorganic preservatives, leading to low reaction triggering efficiency and reduced rock-breaking effectiveness.
Innovation Solution
A metallic mixture blasting capsule design featuring a rapid-trigger metallic mixture with sodium nitrate, ferric oxide, copper oxide, aluminum, and magnesium powders in the inner cartridge, combined with a solid lubricant and glass filler in the outer cartridge, which facilitates efficient oxidation reaction initiation through an electric spark, enhancing the expansion force and reaction success rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal powder is exposed to air during storage and transport, then the metal powder surface becomes oxidized, but this oxidation makes it difficult to trigger the initial oxidation reaction when electric spark is applied
Solution Approach 1:
The invention divides the blasting system into two separate cartridges: an outer cartridge containing the rapidly expanding metallic mixture (metal salt and metal powder) and an inner cartridge containing the rapid-trigger metallic mixture (combustible powder and oxidizing agent). This segmentation allows the metal powder in the outer cartridge to remain unoxidized during storage and transport, preserving its reactivity, while the inner cartridge serves as a separate ignition source that reliably initiates the reaction when needed.
Solution Approach 2:
The inner cartridge is pre-filled with a rapid-trigger metallic mixture that is specifically designed to ignite reliably when exposed to electric spark. This preliminary preparation of the ignition mixture ensures that the initial oxidation reaction can be reliably triggered without being affected by the oxidation state of the metal powder in the outer cartridge.
2Reliability
If conventional single-cartridge design is used, then device complexity is low, but reaction triggering reliability is insufficient
Solution Approach 1:
The invention employs a nested cartridge structure where the inner cartridge containing the rapid-trigger metallic mixture is placed inside the outer cartridge containing the rapidly expanding metallic mixture. This nested design allows the ignition system and explosive mixture to be integrated in a compact form while maintaining their functional independence, thereby improving triggering reliability without excessively increasing overall device complexity.
3Reliability
If more energy is applied to initiate oxidation reaction, then reaction success rate improves, but energy consumption increases
Solution Approach 1:
The inner cartridge containing the rapid-trigger metallic mixture acts as an intermediary that efficiently converts the electric spark energy into a reliable ignition source. This intermediary mixture has properties optimized for low-energy ignition, allowing the system to achieve reliable reaction initiation with minimal electric spark energy input, thereby improving energy efficiency while maintaining rock-breaking effectiveness.
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
Significantly improves the triggering of oxidation reactions, allowing for at least ten times more cartridges to be blasted simultaneously with the same energy, enhancing work efficiency and ensuring low noise and vibration, thus improving rock-breaking operations.
Implementation Method 1
an electric spark at 1500° C or higher is generated between the electrodes by melting the resistance wire
Implementation Method 2
oxygen decomposed in the metal salt between the thermally shocked electrodes instantaneously combines with the vaporized metal powder, resulting in a chain oxidation reaction
Implementation Method 3
a high temperature of 10,000° C or more is generated again and the metal powder in the cartridge is instantly oxidized
Implementation Method 4
the volume of the metal powder, the metal salt and the oxidation reaction product is rapidly expanded
Data Source
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AI summary
The present invention relates to a metallic mixture blasting capsule comprising: an outer cylinder; an inner cylinder accommodated inside the outer cylinder; a rapidly expanding metallic mixture composed of a sodium nitrate powder which is an oxidizing agent, a ferric oxide powder which is an oxidizing agent, an aluminum powder which is a reducing agent, a solid lubricant powder which is an anti-friction agent between powders, and an inorganic filler powder which is a filler for pores between powders, and is filled between the outer cylinder and the inner cylinder; a rapidly detonating metallic mixture composed of a sodium nitrate powder which is an oxidizing agent, a ferric oxide powder which is an oxidizing agent, a copper oxide powder which is an oxidizing agent, an aluminum powder which is a reducing agent, and a magnesium powder which is a reducing agent, and is mixed in a weight ratio greater than that of the aluminum powder and filled in the inner cylinder; and an electric spark generation means embedded in the rapidly detonating metallic mixture.