Gas-Generating Device for Rock Detachment

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Solution Overview

Problem

Existing methods for detaching monoliths from rock massifs in seismically sensitive regions face challenges such as generation of vibrations, air shock waves, micro-cracks, and scattered rock fragments due to high-velocity detonation of explosive charges, which limits their effectiveness and safety.

Innovation Solution

A method using gas-generating devices with a ternary chemical mixture of sodium chlorate, iron oxide, and diesel engine fuel oil, ignited to produce high pressure gas (up to 100 MPa) for rock detachment without detonation, reducing fragmentation and seismic wave interaction, and featuring a compact design for safe storage and transport.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-velocity detonation of explosive charges is used to detach monoliths from rock massif, then rock detachment efficiency is improved, but generation of vibrations, air shock waves, micro-cracks, and scattered rock fragments increases

Engineering Contradiction:
Improverock detachment efficiencyVSAvoidvibrations, air shock waves, micro-cracks, and scattered rock fragments
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the fundamental parameter of the explosive action from high-velocity detonation to controlled gas generation at lower velocities. The gas-generating device produces high pressure gas (up to 100 MPa) through controlled combustion rather than detonation, fundamentally altering the physical parameters of the energy release process to eliminate harmful effects while maintaining detachment effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical detonation process with a chemical gas generation process. Instead of using traditional explosive charges that rely on shock wave propagation, the device uses a ternary chemical mixture (sodium chlorate, iron oxide, and diesel engine fuel oil) that generates high pressure gas through controlled combustion, substituting a chemical-mechanical system for a purely mechanical shock wave system

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

2Force

If traditional explosive charges are used for rock detachment, then detachment force is sufficient, but safety during storage and transport deteriorates due to detonation properties

Engineering Contradiction:
Improvedetachment forceVSAvoidsafety during storage and transport
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The invention changes the operational parameter of the chemical reaction from detonation (supersonic combustion) to controlled deflagration (subsonic combustion). The ternary mixture is formulated to burn at controlled rates producing high pressure gas without detonation, fundamentally changing the velocity and pressure profile of the energy release to enable safe storage and transport while maintaining sufficient detachment force

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces an intermediary substance (diesel engine fuel oil) into the chemical mixture that acts as a controlled fuel source. This intermediary component regulates the combustion process, ensuring that the reaction proceeds through controlled burning rather than detonation, thereby mediating between the need for high force and the requirement for safety during storage and transport

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 method effectively detaches rock monoliths with reduced fragmentation and seismic impact, ensuring safer operations by controlling gas pressure and minimizing rock scattering, while being safer for storage and transport due to non-detonation properties.

Implementation Method 1

ignition of the mixture initiated by initiating devices, generating heat and gas with pressure amounting to 95-105 MPa

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

generation of heat and gas with pressure amounting to 95-105 MPa, causing detachment of monolith from rock massif

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP2660555B1A method of detaching a monolith from rock massif and a device for application of the method
Publication Date: 2016.02.17 CEBAR - DG
  • EP2660555B1 patent drawingFigure 1~3
  • EP2660555B1 patent drawingFigure 4~8
  • EP2660555B1 patent drawing

AI summary

A method of detaching a monolith from rock massif, consisting in that, depending on length and volume of the monolith (1) to be detached from rock massif (2) or concrete block (1) to be split, shot holes (3) are drilled in such massif or block with identical diameter d = 25-75 mm, identical distance between holes c = 10-25 cm, identical distance e = 10-15 cm of the outermost holes (4) from the edges (5 and 6) of the main massif (2) and identical distance k = 10-20 cm from lower plane (7) of the monolith (1) to be detached. Next, depending on the diameter (d) and number of holes (3), prepared is the same number of identical gas-generating devices (8) having casings, made preferably of polyethylene, adapted to diameter and height of the holes and equipped with initiating device (11) provided with pyrotechnic igniter (16) equipped with electric wires (17) that is surrounded with binary mixture (12) containing 88-105 parts by weight of sodium chlorate (NaClO3) and 0.8-1.5 parts by weight of iron oxide, functioning as a catalyst of burning. Further, 7.8-13.5 parts by weight of fuel oil (19) for diesel engines is injected into the mixture by means of any commonly known method and the so prepared and tightly closed gas-generating devices (8') are placed, depending on height (H) of the shot holes (3), in at least one row on bottoms of the holes in such a way that their electric wires (17) protrude above the surface of the monolith to be detached, and further the commonly known operations are performed related to sealing the holes by means of clay, sand, or their mixture and igniting said ternary mixture initiated by initiating devices (11) and generating heat and gas with pressure amounting to 95-105 MPa resulting in detachment of monolith (1) from rock massif (2) or avalanche massif or splitting a concrete block (1).