Experimental Enrichment of Low-Concentration Ventilation Air Methane in Free Diffusion Conditions

Enrichment experiment of ventilation air methane (0.5%) by the mechanical tower

Methane is one of the most important gases leading to the earth's air pollution. Ventilation air methane(VAM) is an important part of the gas discharged into the atmosphere. The volume concentration of methane is generally less than 0.5% in coal mines. Recycling low concentration is facing challenges. To explore the law of low concentration methane enrichment, the enrichment tower for methane was designed and manufactured. The experiment was divided into two types - free diffusion and weak eddy enrichment, and eight kinds of low concentration gas experimental program. Under free diffusion conditions, the maximum methane concentration of the top (middle) tower is 0.64% (0.53%). In the condition of weak eddy field, the maximum methane concentration is 0.67% (0.69%) in the top (middle) tower. The effect of methane enrichment in the weak eddy field is obvious. Methane enrichment method under the eddy current field can greatly increase methane enrichment efficiency and achieve the goal of CMM (coal mine methane) power generation.