3 research outputs found
Experimental study on flow characteristics of gas transport in micro- and nanoscale pores
Gas flow behavior in porous media with micro-and nanoscale pores has always been attracted great attention. Gas transport mechanism in such pores is a complex problem, which includes continuous flow, slip flow and transition flow. In this study, the microtubes of quartz microcapillary and nanopores alumina membrane were used, and the gas flow measurements through the microtubes and nanopores with the diameters ranging from 6.42 mu m to 12.5 nm were conducted. The experimental results show that the gas flow characteristics are in rough agreement with the Hagen-Poiseuille (H-P) equation in microscale. However, the flux of gas flow through the nanopores is larger than the H-P equation by more than an order of magnitude, and thus the H-P equation considerably underestimates gas flux. The Knudsen diffusion and slip flow coexist in the nanoscale pores and their contributions to the gas flux increase as the diameter decreases. The slip flow increases with the decrease in diameter, and the slip length decreases with the increase in driving pressure. Furthermore, the experimental gas flow resistance is less than the theoretical value in the nanopores and the flow resistance decreases along with the decrease in diameter, which explains the phenomenon of flux increase and the occurrence of a considerable slip length in nanoscale. These results can provide insights into a better understanding of gas flow in micro-and nanoscale pores and enable us to exactly predict and actively control gas slip
Analysis of hidden safety hazards and treatment suggestions when the floating roof of oil storage tanks falls to the bottom
In the actual production and operation of enterprises, it is sometimes inevitable that the floating roof will fall to the bottom. This paper calculates the explosion limit of the mixture of oil gas under the floating roof, and confirms that the concentration of oil gas will be within the explosion limit under certain circumstances. Through the monitoring and analysis of the oil-gas mixing space below the floating roof, corresponding control measures are proposed to deal with the potential safety hazards of the floating plate falling to the bottom