Downflow knockback condenser
AssigneeButts Properties, Ltd.
InventorRayburn Butts
Life of this patent
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Abstract
An apparatus and method useful for partially condensing vapor in the upper section of a fractionation tower to separate and remove a lighter gaseous fraction from a condensed liquid component, such as nitrogen from natural gas. A downflow, knockback condenser is disclosed that utilizes a vapor riser to introduce a flow of vapor into a headspace above a vertical tubular heat exchanger, thereby establishing a downflow of condensed liquid and a lighter gaseous fraction through the heat exchange tubes.
Claims31
A condenser apparatus useful for removing gaseous nitrogen from nitrogen-containing natural gas, the apparatus comprising:
- a substantially cylindrical shell;
- a plurality of substantially vertical heat exchange tubes disposed inside the shell;
- a riser introducing vapor comprising natural gas and nitrogen into a headspace above the tubes;
- a refrigerant flowing upwardly through the shell around the tubes and sufficiently cooling the tubes to condense natural gas passing downwardly through the tubes, thereby liquefying the natural gas and separating it from the gaseous nitrogen;
- an outlet disposed below the tubes for receiving gaseous nitrogen exiting the tubes;
- and
- a receptacle disposed below the outlet for receiving liquefied natural gas exiting the tubes.
Apparatus useful for partially condensing vapor in the upper section of a fractionation tower to separate a lighter gaseous fraction from a condensed liquid component, the apparatus comprising:
- a substantially cylindrical shell;
- a condenser section having upper and lower tube sheets attached transversely to the inside of the shell, the tube sheets supporting a plurality of spaced-apart, vertically oriented, heat exchange tubes extending between the upper and lower tube sheets, and providing fluid communication through the tubes;
- refrigerant inlet and outlet ports disposed so as to establish a generally upward flow of refrigerant around the heat exchange tubes between the lower and upper tube sheets;
- a vapor riser providing fluid communication between a space in the fractionation tower disposed below the lower tube sheet and a headspace disposed above the upper tube sheet, thereby establishing an upward flow of vapor through the riser and a downward flow of vapor, condensed liquid and lighter gaseous fraction through the heat exchange tubes;
- a vapor outlet port disposed below the lower tube sheet to receive the lighter gaseous fraction and any remaining vapor exiting the lower tube sheet;
- and
- condensed liquid recovery apparatus disposed below the lower tube sheet and below the vapor outlet port to receive liquid condensed from the vapor.
A method for partially condensing a vapor to separate a lighter gaseous fraction from a condensed liquid fraction, the method comprising the steps of:
- providing a condenser having a substantially cylindrical, vertically oriented shell, upper and lower tube sheets attached transversely to the inside of the shell, the tube sheets supporting a plurality of spaced-apart, vertically oriented, heat exchange tubes extending between the upper and lower tube sheets, and providing fluid communication through the tubes;
- providing refrigerant inlet and outlet ports disposed in the shell so as to establish a generally upward flow of refrigerant around the heat exchange tubes between the lower and upper tube sheets;
- providing a vapor riser providing fluid communication between a space in the shell disposed below the lower tube sheet and a headspace disposed above the upper tube sheet;
- establishing an upward flow of vapor through the riser and a downward flow comprising vapor, condensed liquid and lighter gaseous fraction through the heat exchange tubes, the refrigerant having sufficient cooling capacity to condense a desired liquid fraction from the vapor while passing through the heat exchange tubes;
- and
- separately recovering the lighter gaseous fraction and condensed liquid below the heat exchange tubes.
Dependencies are inferred from the claim text.