Experimental Study On Gas-Soild Flow Characteristics Inside A Closed Cover Of The SVQS

The SVQS of the riser is a new type of quick separation structure.In this paper,a set of SVQS with a diameter of 586 mm and a seal boot with a septum tube is used to investigate the macroscopical flow characteristics of the particles near the wall of a seal boot.At the same time,the PV-6D optical fiber measurement system is used to compare the influence of different operating conditions(The gas velocity of the riser and the particle circulation strength)on particle concentration distribution inside the closed cover.In addition,gas pulse tracing technique was used to measure the gas concentration of riser inside the closed cover,and comparing the influence of the concentration distribution on the axial and radial position of the different gas velocity of stripper and the riser.On this basis,according to the calculation method proposed in this paper,the extraction rate of the riser gas in the axial space of the seal boot is compared and analyzed under different conditions.The following main research results are obtained:(1)Solid particles gather near the wall of the closed cover to form a swirling zone and spiral downward along the wall of the cylinder.The increasing of the axial distance will result in the increase and decrease of the swirl band width and spacing respectively,and the angle of the horizontal direction increases gradually,and the angle decreases with the increase of the gas velocity of the riser.(2)The radial particle concentration at the near wall of the closed cover increases with the increase of the cyclic strength and the gas velocity of the riser;the average concentration of each axial section increases with the increase of the cyclic strength,and if the gas velocity of the riser is higher,the change of the average concentration of each axial section gradually tends to be gentle,and the concentration value gradually becomes stable.(3)If there is no particle circulation,the local concentration of gas in the riser is gradually increasing from the center of the bed to the near wall of the closed cover in the radial position.With the particle circulation exiting,the local concentration of the gas in the riser presents the center is higher and the distribution of the side wall is lower in the radial position.(4)If there is no particle circulation,The extraction rate of the riser gas gradually increases with the gas velocity of stripper increasing,and gradually decreases with the increase of the gas velocity of the riser.If there is a particle circulation,the extraction rate of the gas in the riser increases first gradually increases with the increase of the gas velocity of the riser,and then becoming stable,the rising of the stripping gas speed will make the extraction rate of the rising gas relatively increased,while the increasing of particle circulation strength will decrease the extraction rate.