Improvement and evaluation on binary mixing method of methane and air in large-scale confined space

Gas mixing is an interesting topic in industrial and scientific research fields. Based on the basic structure of an blasting vessel with a volume of 10 m³, this work designed an applicable gas-intake device and theoretically improved the gas intake technology. Then a series of experiments on the whole mixing process of methane and air were carried out in different conditions. According to the evaluation criteria on the gas mixing effect, specific sizes of the gas-intake device and relevant gas-intake conditions were determined. Results indicate that, when the hole diameter of gas-intake device is 1.5 mm and the separation distance is 100 mm, the gas mixing effect reach the optimal condition; and when the gas-intake velocity is fixed at 8 m³/h, and the pressure difference inside and outside the vessel is chosen as 0.04 MPa, the gas mixing effect are further optimized. After being compared with the original binary mixing result, the new system can shorten the mixing time by eleven times and make the mixing more homogeneous. The results in this study provide experimental data and basis for further study on gas mixing in a large scale confined vessel or space.