Application Scope

The gas content determination device is primarily used for directly measuring the original gas content of coal seams and the original desorbable gas content of coal seams. It can be applied in gas emission prediction, outburst risk assessment for working faces and regions, evaluation of pre-drainage gas effectiveness, and the compilation of gas geological maps.

Product Principle

By drilling directly underground to collect coal cuttings from predetermined depths, the gas desorption rate and desorption volume of the coal cuttings are measured. A specific mathematical model is used to calculate the gas loss before the coal sample is sealed in the sample container. Laboratory measurements of relevant parameters are conducted to determine the original gas content and original desorbable gas content. This equipment employs a fixed-point sampling method, and the measurement results show a strong correlation with actual gas emission dynamics and outburst prediction indicators (such as drilling cuttings desorption index and initial gas emission rate). The measurement results meet the requirements for predicting gas emissions and coal-rock dynamic disasters in underground coal mines. The technology and accompanying instruments of this achievement have been successfully promoted and applied in multiple mines across China.

Technical Parameters

Testing time: <2h

Underground Coring and On-site Desorption System

Specialized underground desorption instrument: single test range 800ml (can be customized to 1000ml upon customer request), high-brightness corrosion-resistant acrylic tube, stable base, clear graduations;

Underground desorption cylinder accuracy: 2ml; single range 800ml or 1000ml.

Underground desorption time: 0-30min;

Specialized coal sample container: material stainless steel/alloy, capacity 800g or more;

Surface Gas Desorption System

Pressure sensor range: 10Kpa

Pressure sensor accuracy: 0.1% FS

Temperature: 0°C to 100°C

Atmospheric pressure: 600hpa-1100hpa

Coal Sample Weighing System

Digital display electronic balance maximum capacity: 2000g

Electronic balance sensitivity: 0.1g

Power supply voltage: 220v

Ambient temperature: 5-35°C

Power: 5W

Specialized coal sample weighing containers: one each of 100g and 200g

Specialized coal sample weighing spoons: one each of 50g and 100g

Coal Sample Crushing and Desorption System

Crusher feed particle size: ≤30mm;

Crusher discharge particle size: 40-180 mesh;

Operating power supply: 220V, 50HZ;

Single feed capacity: ≤1000g/bowl;

Crushing time: adjustable (0-5)min;

Motor power: 0.75kW

Crusher features: low noise, effective crushing.

Moisture Determination System

Maximum load: 110g

Minimum division value: 5mg

Minimum sample amount: 0.5g

Moisture determination accuracy: 0.1g%

Data Processing System

Software operating environment: This software runs on Windows XP and Win7 systems;

Main software functions: User management, data process report output, experimental result report output, experimental data report output, calculation of gas content W value, calculation of desorbable gas content Wa and residual gas content Wc, calculation of gas pressure P, calculation of cumulative gas desorption volume Q, report output, printing, and help.