Experimental Study On Device Of Continuously Depressurizing And Discharging Granular

The pressure drop characteristics of standpipe,pressure drop characteristic of screen device and powder processing capacity were investigated experimentally on the continuous powder depressurization device.The following conclusions were obtained.1.Experiment of standpipe pressure drop characteristics1)When pressure of silo stays the same,the superficial solid velocity has little influence on pressure drop of standpipe.However the pressure drop of standpipe increases with the raise of the superficial gas velocity.And the pressure drop of standpipe increases with the increase of the pressure of silo.2)When the superficial gas velocity is less than 0.2m/s,the voidage has little change with the increase of superficial solid velocity and superficial gas velocity.However,the voidage increases with the raise of inlet pressure.It was found that the voidage can be calculated by the fitting formula which is a function of inlet pressure.With the fitting formula of voidage and Ergun equation,the pressure drop can be conveniently calculated.The maximum deviation between the calculated values and experimental data is less than 20%.2.Experiment of pressure drop in the screen device1)For the same granular material,pressure drop of the screen device increases with the displacement of the screen device increasing.2)When the displacement of the screen device stays the same,the pressure drop of the screen device decreases with the increase of the powder size.3)At the same pressure of silo,the proportion of pressure drop in screen device increases with the increase of the displacement of the screen device.3.Experiment of the discharge flow rate1)With the increase of the inlet pressure of L section,the discharge flow rate increases slowly at first.When the inlet pressure increases to a certain value,the discharge flow rate increases rapidly and the inlet pressure of the L section decreases spontaneously.2)When the larger diameter of the pipe is used,the start pressure of discharge is lower and the discharge flow rate is larger.The slope of the discharge curve is correspondingly greater.3)When the materials with a larger average particle size is used,the starting pressure of discharge is lower.When the inlet pressure keeps constant,the discharge flow rate increases with the increase of average particle size.