Fluid contact tray particularly for the use in an offshore fractionation column

1. A fractionation column ( 1 ) comprising:

a housing ( 29 ) and at least one fluid contact tray ( 10 ), wherein the fluid contact tray is a vapor-liquid contact tray and wherein the tray ( 10 ) comprises:

a tray deck ( 12 ) comprising an active mass transfer surface ( 20 ) suitable for contacting a fluid (g) and a fluid (l), wherein fluid (l) has a higher density than fluid (g), wherein the active mass transfer surface ( 20 ) comprises one or more orifices ( 18 ) for the passage of & fluid (g), and wherein at least two at least partially radially extending separation walls ( 22 - 1 , 22 - 2 , 22 - 3 , 22 - 4 ) and/or at least one separation weir ( 42 ) are arranged on the active mass transfer surface ( 20 ), which divides the active mass transfer surface ( 20 ) into at least two sections ( 24 - 1 , 24 - 2 , 24 - 3 , 24 - 4 ),

an annular channel ( 26 ) having a bottom area ( 28 ) suitable for collecting fluids ( 1 ), which is arranged at the peripheral area of the active mass transfer surface ( 20 ) and embraces or partially embraces the mass transfer surface ( 20 ),

a central downcomer ( 34 ) for collecting and discharging fluid (l) from the annular channel ( 26 ), wherein the central downcomer ( 34 ) has the form of a hollow body with an opening ( 36 ) in the bottom section thereof being suitable for the distribution of liquid vertically downwardly, and wherein the central downcomer ( 34 ) is non-rotatably fixed at the fluid contact tray ( 10 ), and

at least one conducting means ( 40 ) for transferring fluid collected in the annular channel ( 26 ) from the annular channel ( 26 ) to the central downcomer ( 34 ),

wherein the fractionation column ( 1 ) comprises at least two fluid contact trays ( 10 ), which are arranged so as to allow the distribution of liquid vertically downwardly from the opening ( 36 ) of the downcomer ( 34 ) of one fluid contact tray ( 10 ) onto the upper side of the tray deck ( 12 ) of the adjacent fluid contact tray ( 10 ).

2. The column ( 1 ) according to claim 1 , wherein the active mass transfer surface ( 20 ) has, in top view, the form of at least substantially a circular ring and wherein the fluid contact tray ( 10 ) is formed at least substantially symmetrically and wherein the tray deck ( 12 ) comprising the active mass transfer surface ( 20 ) and at least partially radially extending separation walls ( 22 - 1 , 22 - 2 , 22 - 3 , 22 - 4 ) and/or separation weir ( 42 ) is substantially rotation-symmetrically with respect to the axis (A), which extends through the center of the tray perpendicular to the tray deck ( 12 ).

3. The column ( 1 ) according to claim 1 , which is configured so that in operation liquid ( 1 ) flows on the active mass transfer surface ( 20 ) from its radially inner end to its peripheral area and that liquid ( 1 ) is transferred from the annular channel ( 26 ) to the central downcomer ( 34 ) located in the center of the fluid contact tray ( 10 ).

4. The column ( 1 ) according to claim 1 , wherein between 2 and 8 at least partially radially extending separation walls ( 22 - 1 , 22 - 2 , 22 - 3 , 22 - 4 ) are arranged on the active mass transfer surface ( 20 ), and/or, wherein between 1 and 8, separation weirs ( 42 ) are arranged on the active mass transfer surface ( 20 ).

5. The column ( 1 ) according to claim 1 ,

wherein the at least two at least partially radially extending separation walls ( 22 - 1 , 22 - 2 , 22 - 3 , 22 - 4 ) extend from the radially outer periphery line of the active mass transfer surface ( 20 ) over more than 50% to less than 100% of the distance between the peripheral line of the active mass transfer surface ( 20 ) and the center of the tray deck ( 12 ).

6. The column ( 1 ) according to claim 1 , wherein at least one at least partially radially extending partition wall ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) is arranged on the bottom area ( 28 ) and/or in the top area of the annular channel ( 26 ), wherein the at least one at least partially radially extending partition wall ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) extends substantially in vertical direction.

7. The column ( 1 ) according to claim 6 , wherein between 1 and 8 at least partially radially extending partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) are arranged on the bottom area ( 28 ) and/or in the top area of the annular channel ( 26 ).

8. The column of claim 7 , wherein the number of partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) arranged on the bottom area ( 28 ) and/or in the top area of the annular channel ( 26 ) is equal to the number of the separation walls ( 22 - 1 , 22 - 2 , 22 - 3 , 22 - 4 ) arranged on the active mass transfer surface ( 20 ).

9. The column ( 1 ) according to claim 6 , wherein the tray ( 10 ) comprises at least two at least partially radially extending partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ), wherein the at least partially radially extending partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) are arranged substantially equally spaced apart from each other on the bottom area ( 28 ) and/or in the top area of the annular channel ( 26 ), so that the annular channel ( 26 ) is divided by the partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) into substantially equally sized sections ( 32 - 1 , 32 - 2 , 32 - 3 , 32 - 4 ).

10. The column ( 1 ) according to claim 1 , wherein the tray deck ( 12 ) is sloped downwardly, either from center of the tray deck ( 12 ) to the periphery of the active mass transfer surface ( 20 ) or from the radially inner end of the active mass transfer surface ( 20 ) to the periphery of the active mass transfer surface ( 20 ), with a negative angle (α) measured in radial direction with respect to the horizontal plane of 2 to 10°.

11. The column ( 1 ) according to claim 1 , wherein the at least one conducting means ( 40 ) is a pipe, wherein one opening of the pipe ( 40 ) opens out into the lower part of the annular channel ( 26 ) and the other opening of the pipe ( 40 ) opens out into the central downcomer ( 34 ).

12. The column ( 1 ) according to claim 1 , wherein at least one at least partially radially extending partition wall ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ) is arranged on the bottom area ( 28 ) of the annular channel ( 26 ) dividing the annular channel ( 26 ) in a number of sections ( 32 - 1 , 32 - 2 , 32 - 3 , 32 - 4 ) corresponding to the number of the partition walls ( 30 - 1 , 30 - 2 , 30 - 3 , 30 - 4 ), wherein the fluid contact tray ( 10 ) comprises equal or a greater number of conducting means ( 40 ) than the number of sections ( 32 - 1 , 32 - 2 , 32 - 3 , 32 - 4 ).

13. The column ( 1 ) according to claim 1 , wherein the column is an offshore fractionation column.

14. A method for use of a fractionation column ( 1 ) according to claim 1 comprising the steps of: providing the fractionation column ( 1 ) according to claim 1 , introducing fluid mixtures to the housing of the fractionation column ( 1 ), and performing a thermal separation process to separate fluid mixtures into their components, wherein the fractionation column ( 1 ) is located offshore.

15. The method of use according to claim 14 , wherein the thermal separation process comprises at least one of:

high pressure distillation in the fractionation column ( 1 ), which is performed at a pressure of at least 6 bar,

removal of a heavy fraction in the fractionation column ( 1 ) from a hydrocarbon mixture, and

removal of light fractions in the fractionation column ( 1 ) from a hydrocarbon mixture.