METHOD AND SYSTEM FOR ORIFICE CONTROL OF VALVE PRESSURE DROP
The present invention relates to a valve tray for use in a chemical process column. The valve tray includes a plurality of apertures formed therein. A plurality of valves are maintained in a spaced relationship relative to individual apertures of the plurality of apertures. An area of the individual apertures is less than an area of individual valves of the plurality of valves.
1 . A valve tray for use in a chemical-process column, the valve tray comprising:
a tray surface having an aperture formed therein, the aperture being of an aperture area;
a valves coupled to the tray surface and disposed in a spaced relationship above the aperture, the valve comprising:
a top surface having a surface area;
an upstream leg coupled to the top surface;
a downstream leg coupled to the top surface;
at least one vane formed on an edge of the top surface, the at least one vane being directed outwardly and downwardly relative to the top surface; and
wherein the aperture area is smaller than the surface area.
2 . The valve tray according to claim 1 , wherein the aperture is trapezoidal shaped.
3 . The valve tray according to claim 1 , wherein the aperture comprises opposed ends of a lateral width and a central portion of a reduced lateral width relative to the opposed ends.
4 . The valve tray according to claim 1 , wherein the aperture is bordered by two slots.
5 . The valve tray according to claim 1 , wherein the valve is a fixed valve.
6 . The valve tray according to claim 1 , wherein the valve is a floating valve.
7 . The valve tray according to claim 1 , wherein the valve comprises an orifice formed in the downstream leg.
8 . The valve tray according to claim 7 , wherein the valve comprises a tab formed adjacent to the orifice.
9 . The valve tray according to claim 1 , wherein the valve comprises two vanes formed on oppositely-disposed edges of the top surface.
10 . The valve tray according to claim 1 , the aperture area is in the range of approximately 87% to approximately 50% of the surface area.
11 . The valve tray according to claim 1 , wherein the vane directs ascending fluid in a downward direction thereby creating a vena contracta between a lower edge of the vane and the tray surface.
12 . A method of controlling valve pressure drop in a valve tray, the method comprising:
forming a valve tray having an aperture formed therein, the aperture facilitating passage of a first fluid therethrough;
positioning a valve in a spaced relationship over the aperture;
mixing the first fluid flowing upwardly through the aperture with a second fluid flowing downwardly across the valve tray;
wherein the aperture is of restricted size relative to the valve to facilitate control of pressure drop across the valve.
13 . The method of claim 12 , wherein the restricted aperture size reduces spray height.
14 . The method of claim 12 , comprising creating a vena contracta between the valve and the valve tray via a vane disposed on an edge of the valve.
15 . The method of claim 14 , wherein the vane directs the first fluid outwardly and downwardly relative to the valve.
16 . The method of claim 14 , wherein the vena contracta encourages the first fluid to distribute across the valve tray.
17 . The method of claim 12 , wherein the aperture is trapezoidal shaped.
18 . The method of claim 12 , wherein the aperture comprises opposed ends of a lateral width and a central portion of a reduced lateral width relative to the opposed ends.
19 . The method of claim 12 , wherein an area defined by the aperture is in the range of approximately 87% to approximately 50% of a surface area of a cover associated with the valve.
20 . The method of claim 12 , wherein the valve comprises two vanes formed on oppositely-disposed edges of the top surface.