Experimental Study On Flow Patterns And Their Operating Regions Of Concurrent Gas-liquid Downward Flow Through Tridimensional Rotational Sieve Tray

Tridimensional rotational sieve tray is a new-type column internals researched by Zhang Shaofeng research group of Heibei University of Technologyindependently,which drew lessons from the advantages of sieve plate,swirl plate and many other kinds of tridimensional composite trays.So this kind of tray has the advantages of large circulation area,mass transfer efficiently,lower pressure drop and less flooding.Cooperating with gas-liquid concurrent flow,tridimensional rotational sieve tray is more advantageous in the field of absorption,such as desulfurization and dust removal.Research group has studied fpressure drop and mass transfer of concurrent gas-liquid downward flow through tridimensional rotational sieve trays by experiment,but it is not researched that flow patterns and their operating regions of gas-liquid in tridimensional rotational sieve trays'internal space.Therefore,at room temperature and atmospheric pressure,this experiment has collected differential pressure fluctuation signal and taken photos in cold model absorber with diameter of 150×5mm using air-water using air-water as system.And this paper has distinguished and divided flow patterns and their operating regions by analysing signal and photos.This paper is also studies the influence of tridimensional rotational sieve tray structural parameters and installation by changing the number of the tray vanes,torsion angles and rotational direction of two trays.Experimental results show that there are four kinds of flow patterns found in tridimensional rotational sieve tray,called continuous-stratified flow,bubbling-stratified flow,slug flow and foam flow.Sprinkle density?L_w?and kinetic energy factor?F_s?are the main factors that influence the flow patterns and their operating regions.Tridimensional rotational sieve tray structural parameters and stallation impact every kind of flow pattern's operating regions.L_w is the main factor that affect the flow patterns.In conditions of installing one N8-A90-C tray,when L_w<70 m³·?m²·h?^-1,it was continuous-stratified flow;when L_w=70¹45 m³·?m²·h?^-1,it was bubbling-stratified flow or plug flow;when L_w>145m³·?m²·h?^-1,it was foam flow;when L_w=70¹45 m³·?m²·h?^-1,transformation of bubbling-stratified flow and plug flow was affected by F_s,it was bubbling-stratified when Fs<1.95(m·s^-1)(kg·m^-3)^0.5 and it was plug flow when F_s>2.34(m·s^-1)(kg·m^-3)^0.5.In the case of one tridimensional rotational sieve tray,operating regions of the patternsvary with its structural parameters.The more the number of vanes of a tridimensional rotational sieve tray is,the narrower operating regions of continuous-stratified flow and bubbling-stratified flow are,the wider the operating regions of slug flow and foam flow are.The effect of the number of vanes has greater influence on bubbling-stratified flow and slug.The larger torsion angle of a vane is,the wider the operating regions of the continuous-stratified flow and slug flow are,the narrower the operating regions of bubbling-stratified flow and foam flow are.Torsion angles have greater influence on continuous-stratified flow,bubbling-stratified flow and slug flow.When two tridimensional rotational sieve tray are installed,whether install in the same direction or install reversel,the flow operating regions of upper tridimensional rotational sieve tray is same with installed one tray;for lower tridimensional rotational sieve tray,when installed in the same direction,the flow pattern operating regions of continuous-stratified flow and bubbling-stratified flow are wider than upper one,and the flow pattern operating regions of slug flow and foam flow are narrower;while install reversely,operating regions of slug flow and foam are wider than upper one,the continuous-stratified flow and bubbling-stratified flow is narrower than the upper.