Study On The Influence Of The Mixing Uniformity Of Combustible Gas On Its Explosion Characteristics

To test the explosion characteristics of combustible gas,a certain percentage mixed gas with flammable gases and air was needed to be added to the test device.The test results would be affected by the uniformity of the mixed gas.The uneven mixing of gases would directly lead to inaccurate test results and indirectly lead to the production of safety hazards.To solve this problem and research on the influence rule of uniformity of the mixed gas,a gas mixer was designed to improve the uniformity of mixed gas and control the mixing ratio between different gases in this paper.A secondary mixer was designed after considering the advantages and disadvantages of various combinations of gases.In this secondary mixer,the first level was a jet mixer which was based on t-tube and venturi tube.The second level was designed with the principle of "division-position moving-remixing".After detection,the secondary mixer could make the flammable gas and air mixed more evenly.Tests were conducted under two conditions,a two-stage mixer and a non-mixer,to contrastive and analysis study the influence of the uniformity of the gas mixture on the combustible gas explosion characteristics.The test results shows that:(1)Under the action of a two-stage mixer,the explosion limit range of hydrogen,methane,liquefied petroleum gas broaden 2.24%,4.2%,5.45% than that without gas mixer.The combustible gas explosion limit range is related to the molecular weight,and broaden with the increase of relative molecular mass.(2)The best explosive concentration of methane and liquefied petroleum gas are 10.9% and 6.2% under the action of a two-stage mixer.(3)Under the action of a two-stage gas mixer,the explosion pressure of the combustible gas is higher than that without the mixer,so the more uniform the combustible gas and the air are mixed,the explosion pressure is the higher.This indicates that the combustible gas previously evaluated is still very dangerous out of range of explosion limits.When selecting the safety factor in the future,factors that affect all aspects should be fully taken into consideration in order to be safety.At the same time,this paper explores and studies the combustibility of combustible gas mixers and combustible gases on the explosion characteristics,filling the gaps in domestic research in this area.