Alternating Mine Gallery Ventilation for High Gas Working Faces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The presence of residual gas in coal seams during mining poses a challenge for mine ventilation, as it can enter mine galleries and disrupt normal ventilation and production, while excessive coal pillar width leads to resource loss and high extraction costs.
Innovation Solution
The method involves dividing an isolated island working face into sections, alternating coal pillars as conventional and gas-drainage sections, and using mine galleries for alternating air intake and return, with gas-drainage holes connecting the galleries to the goaf for controlled gas extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the coal pillar width between the mine gallery and the goaf is reduced, then the loss of coal resources is minimized, but transverse fissures occur within the coal pillar which communicate the mine gallery with the goaf, causing gas to enter the mine gallery and affect normal ventilation and production
Solution Approach 1:
The coal pillar is segmented into alternating conventional sections and gas-drainage sections along the strike direction. This segmentation allows the coal pillar to maintain structural integrity while providing dedicated zones for gas drainage, preventing gas infiltration into the mine gallery without requiring excessive coal pillar width.
Solution Approach 2:
Gas drainage holes are drilled from the gas-drainage sections into the goaf to extract gas before it can enter the mine gallery through transverse fissures. This proactive extraction removes the harmful gas source, maintaining ventilation reliability while allowing thinner coal pillars.
2Object-affected harmful factors
If surface drilling is performed to the goaf for gas extraction, then gas in the goaf can be extracted, but large construction and equipment costs are incurred
Solution Approach 1:
The coal pillar itself serves as an intermediary medium for gas drainage. By drilling gas drainage holes through the coal pillar from the mine gallery side, the system uses the existing coal pillar structure as a conduit to reach the goaf, eliminating the need for expensive surface drilling operations while still achieving effective gas extraction.
3Reliability
If the coal pillar width is increased to prevent transverse fissures, then gas entry into the mine gallery is prevented, but coal resources are lost and construction costs increase
Solution Approach 1:
The coal pillar is divided into alternating conventional sections and gas-drainage sections, creating a structured pattern that provides gas drainage functionality without requiring excessive overall width. This segmented approach maintains gas isolation while preserving coal resources and simplifying mine gallery arrangement.
Solution Approach 2:
Gas drainage holes are drilled in advance from the gas-drainage sections into the goaf before mining operations proceed. This preliminary gas extraction action prevents gas accumulation and potential entry into the mine gallery, maintaining safety without requiring excessive coal pillar width as a passive barrier.
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
This approach actively manages gas by extracting it from the source, preventing gas accumulation in mine galleries, enhancing ventilation safety, and allowing for the recovery and utilization of gas for power generation.
Implementation Method 1
due to the saddle-shaped distribution and the low density of gas, the gas content in the area of the goaf near the mine gallery on both sides of the island working face is high
Implementation Method 2
feeding a first fresh air into a coal mining area through the first mine gallery to form a first ventilation air methane (VAM) which is discharged through the second mine gallery
Data Source
AI summary
A ventilation method for a high gas working face based on alternating intake and air return in a mine gallery is provided. In this method, an isolated island working face is divided into several sections along a strike direction. A coal pillar is alternately set as a conventional section and a gas-drainage section. Opposite coal pillars in the two mine galleries within the same section are respectively used as the conventional section and the gas-drainage section. Two mine galleries on both sides of the isolated island working face are alternately used as an intake gallery and a return gallery. The coal pillar at the side of the mine gallery as the return gallery is the gas-drainage section. A gas-drainage hole communicating a goaf is provided in the gas-drainage section, so that gas in the goafs at two sides of the isolated island working face can be extracted alternately.