Experimental Study On Flow Characteristics And Pressure Drop Of A Composite Tridimensional Rotational Flow Sieve Tray

With the domestic attention to environmental protection,the goal of"carbon peaking and carbon neutrality"has been put forward.However,in the process of carbon absorption,the absorption tray used is easy to cause flow blockage,and the structure is complex and difficult to disassemble and install,which greatly reduces the efficiency in actual production and treatment.In order to achieve the"double carbon"goal,the development of column internals with high efficiency,large flux and excellent flow characteristics has always been an important goal of CO₂ capture technology.In this paper,in view of the development trend and industrial needs of the anti-blocking,large processing capacity,and high mass transfer of the tray,and referring to the advantages of the composite tray,a new composite tridimensional rotational flow sieve tray（CTRST）with a strong anti blocking,wide operation range and high efficiency is designed combine tridimensional rotational flow sieve tray（TRST）with packing with high specific surface.Air-water is used as the operating medium,the flow characteristics and pressure drop of CTRST were studied.The flow characteristics of tray under co-current and countercurrent operation mode is recorded with image,and the flow pattern and operation domain of tray under co-current flow are defined and divided by combining differential pressure sequence standard deviation analysis and power spectral density analysis.When the gas and liquid are co-current,the flow of the tray is analyzed.In the TRST area of the internal packing-type tray,the membrane-drip column and foam-embolic flow is present,while bubbly and milk froth-ribbon flow is present in the packing area of the external packing-type tray.The change in the flow pattern of the tray is mainly affected by the gas phase,the change of the liquid phase mainly affects the intensity of the fluctuation between the phases in the column,and the change of the cross-sectional proportion and the tray height packing mainly affects the form and position of the operating domain interface.The pressure drop of CTRST under gas-liquid co-current flow was measured,and the effects of tray structural parameters（packing position,twist direction of blades,proportion of cross-section of packing area and tray height）on the pressure drop are investigated.The results show that on the whole,the dry pressure drop is within 160 Pa and that of wet is within900 Pa.In the experimental operating conditions,under the same structural parameters,the pressure drop of the internal packing-type tray is higher than that of the external packing-type tray,and the proportion of cross-section of packing area has the most significant effect on the pressure drop of the tray.Comparing the pressure drop of CTRST in co-current and countercurrent flow mode and the pressure drop of CTRST with other types of trays,and the characteristics of CTRST in pressure drop,flux and fluid distribution was determined.The prediction model of dry and wet pressure drop in CTRST are established,and errors are within 10%and 15.5%respectively.The composite tridimensional rotational flow sieve tray has the advantages of low pressure drop,high flux and good gas-liquid distribution.The tray structure is conducive to the utilization of the space in the tray and has the potential for engineering application.This research can provide theoretical basis and new ideas for the subsequent development and optimization of CTRST.