Experimental Studies On Absorption And Desorption Under Low Vibration Environment

In addition to porosity and coal property, gas absorption and desorption depends on other factors like electric field, stress, temperature and human mining activities. Based on this point, it becomes significant to study associated elements that might affect gas property in order to learn more about removal of coal layers, gas mechanism and gas exploration.Scholars throughout the world carry out experimental studies on these factors and issue theories, which insure safety in process of production. Despite this, few current studies focuses on gas absorption and desorption property in case of low frequency vibration. Gas burst accidents mostly relate to dynamic disturbance such as earthquake and mining activities. Therefore, a vibrator and a testing device are developed to investigate absorption and desorption property in case of low frequent vibration, whose experimental result are analyzed on basis of micro structure, gas permeability, desorption character and vibrating dynamics. It finds that in low vibrating condition, frequency rises up while desorption volume decreases and permeability parameter goes down. Q_d∞,Q_∞remains unchanged . When vibration has continued for specific time and frequency comes below critical point, vibration itself enhances desorption. While frequency goes above critical point, vibration holds up desorption. As soon as frequency reduces, volume and velocity of desorption increases. So does attenuation rate. Desorption intensity and attenuation coefficent decrease as time changes. Therefore, vibration affects desorption. Experimental result, based on absorption and desorption or vibration theories, indicates that sample coal temperature increases by low frequent disturbance. Internal molecular desorption barrier exacerbates, so that interaction potential within molecules expands, exerting greater gas bubble blast and larger absorption sites. Evidently four factors result in various vibrating rates inside sample coal; therefore, low frequent disturbances contributes to decreasing sample porosity and increasing molecular free path, slowing down molecular diffusion inside sample coal. Meanwhile, as tiny layer of porosity form up, absorption areas inside sample coal expand, which eliminates desorption capacity. Moreover, the experiment studies dynamic feature of absorption. Dynamic equation on vibration rate and absorption volume sets up. This research is significantly instructive for preventing concentrated gas explosion and ensuring safe production.