Abstract: In order to explore the methane explosion characteristics under different mixing uniformity conditions and prevent the methane explosion,a two-stage gas mixer composed of a jet mixer and a static mixer was designed,made and used to carry out experiments on mixtures of methane and air.Explosion limits and explosion pressure of methane were studied by using the self-developed test device.The experiment results show that under the action of two stage gas mixer,the lower explosive limit of methane decreases from 5.25% to 5.15%,the upper explosive limit increases from 17.15% to 17.55%,the methane explosion range is expanded by 4.20%,and the upper explosive limit is greatly influenced by the mixing uniformity,that as the methane concentration increases,the increase in explosion pressure increases first and then decreases,that when the volume fraction of methane is 11%,the explosion pressure has the largest increase,and the methane explosion pressure is the most affected by the mixing uniformity.

Key words: methane, mixing uniformity, two-stage gas mixer, explosion limit, explosion pressure