Liquid de-entrainment in heat exchange equipment

Patent metadata

Field	Value
Publication number	US-11389745-B2
Application number	US-202016950430-A
Country	US
Kind code	B2
Filing date	Nov 17, 2020
Priority date	Dec 13, 2019
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

A kettle reboiler includes a shell, a liquid reservoir defined within the shell to contain a first process fluid, and a tube bundle positioned within the liquid reservoir and at least partially submergible in the first process fluid, the tube bundle being configured to circulate a second process fluid that causes the first process fluid to boil and discharge a vapor-liquid mixture. A liquid-vapor separation assembly is positioned in the shell and includes a separation deck, and a plurality of separation devices mounted to the separation deck, each separation device being operable to de-entrain liquid from the vapor-liquid mixture and discharge a vapor. A vapor outlet nozzle is coupled to the shell to receive the vapor discharged from the plurality of separation devices.

First claim

What is claimed is:

1. A kettle reboiler, comprising:
a shell;
a liquid reservoir defined within the shell to contain a first process fluid;
a tube bundle positioned within the liquid reservoir and at least partially submergible in the first process fluid, the tube bundle being configured to circulate a second process fluid that causes the first process fluid to boil and discharge a vapor-liquid mixture;
a liquid-vapor separation assembly positioned in the shell and including:
a separation deck; and
a plurality of separation devices mounted to the separation deck, each separation device being operable to de-entrain liquid from the vapor-liquid mixture and discharge a vapor; and
a vapor outlet nozzle coupled to the shell to receive the vapor discharged from the plurality of separation devices, wherein each separation device comprises:
a body mounted to the separation deck and defining a central flow passage that receives a portion of the vapor-liquid mixture, wherein the body includes:
an outer shell;
an inner shell at least partially arranged within the outer shell, an inner wall of the inner shell comprising one or more ribs provided on and extending into the central flow passage; and
a liquid flow passage defined between the outer and inner shells.

2. The kettle reboiler of claim 1 , wherein each separation device further comprises:
a cyclonic flow initiator arranged within the central flow passage and including a helical structure that defines a helical plane extending about a central axis of the cyclonic flow initiator along a helical path,
wherein, as the portion of the vapor-liquid mixture traverses the helical path, the liquid within the portion of the vapor-liquid mixture is urged radially outward to separate the liquid from the vapor.

3. The kettle reboiler of claim 2 , wherein the body further includes:
a plurality of apertures defined in the inner shell and facilitating fluid communication between the central flow passage and the liquid flow passage to remove the liquid from the central flow passage.

4. The kettle reboiler of claim 3 , wherein the liquid flow passage fluidly communicates with a top of the separation deck to deposit the liquid on the top of the separation deck.

5. The kettle reboiler of claim 2 , wherein at least one of a width, a pitch, and an angle of the helical structure varies along an axial length of the cyclonic flow initiator.

6. The kettle reboiler of claim 2 , wherein at least one of an upper surface and a lower surface of the helical plane defines a structure selected from the group consisting of a dimple, a corrugation, a fin, and any combination thereof.

7. The kettle reboiler of claim 2 , wherein an edge of the helical structure defines a structure selected from the group consisting of a notch, a half-circle, a scallop, a corrugation, a fin, and any combination thereof.

8. The kettle reboiler of claim 2 , further comprising:
a center post extending along the central axis, wherein the helical structure is coupled to and extends about the center post; and
a support structure coupled to the center post at at least two points of contact to support the cyclonic flow initiator within the central flow passage.

9. The kettle reboiler of claim 1 , further comprising a downcomer fluidly coupled to the separation deck to receive the liquid de-entrained from the vapor-liquid mixture.

10. The kettle reboiler of claim 9 , wherein the downcomer extends downward from the separation deck at a point above the liquid reservoir to deposit the liquid into the liquid reservoir.

11. The kettle reboiler of claim 9 , further comprising a liquid outlet chamber defined within the shell, wherein the downcomer extends downward from the separation deck at a point above the liquid outlet chamber to deposit the liquid into the liquid outlet chamber.

12. The kettle reboiler of claim 9 , wherein at least a portion of the separation deck is sloped to flow the liquid toward the downcomer.

13. A method of operating a kettle reboiler, comprising:
containing a first process fluid in a liquid reservoir defined within a shell of the kettle reboiler;
circulating a second process fluid through a tube bundle positioned within the liquid reservoir and at least partially submerged in the first process fluid;
boiling the first process fluid as the second process fluid circulates through the tube bundle and thereby discharging a vapor-liquid mixture from the first process fluid;
receiving the vapor-liquid mixture at a liquid-vapor separation assembly positioned in the shell, the liquid-vapor separation assembly including a separation deck and a plurality of separation devices mounted to the separation deck, wherein each separation device comprises a body mounted to the separation deck and defining a central flow passage, the body including:
an outer shell;
an inner shell at least partially arranged within the outer shell, an inner wall of the inner shell comprising one or more ribs provided on and extending into the central flow passage; and
a liquid flow passage defined between the outer and inner shells;

receiving a portion of the vapor-liquid mixture in the central flow passage;
de-entraining liquid from the vapor-liquid mixture with the plurality of separation devices and discharging a vapor from the plurality of separation devices; and
receiving the vapor discharged from the plurality of separation devices at a vapor outlet nozzle coupled to the shell.

14. The method of claim 13 , wherein a cyclonic flow initiator is arranged within the central flow passage and including a helical structure that defines a helical plane extending about a central axis of the cyclonic flow initiator along a helical path, the method further comprising:
flowing the portion of the vapor-liquid mixture along the helical path; and
urging the liquid within the portion of the vapor-liquid mixture radially outward and thereby separating the liquid from the vapor as the portion of the vapor-liquid mixture flows along the helical path.

15. The method of claim 13 , wherein a plurality of apertures are defined in the inner shell, the method further comprising:
receiving the liquid in the liquid flow passage via the plurality of apertures defined in the inner shell;
flowing the liquid from the liquid flow passage to a top of the separation deck; and
flowing the liquid on the top of the separation deck toward a downcomer.

16. The method of claim 15 , wherein the downcomer extends downward from the separation deck at a point above the liquid reservoir, the method further comprising depositing the liquid into the liquid reservoir from the downcomer.

17. The method of claim 15 , wherein a liquid outlet chamber is defined within the shell and the downcomer extends downward from the separation deck at a point above the liquid outlet chamber, the method further comprising depositing the liquid into the liquid outlet chamber from the downcomer.

18. The method of claim 14 , wherein the helical structure is coupled to and extends about a center post extending along the central axis, the method further comprising supporting the cyclonic flow initiator within the central flow passage with a support structure coupled to the center post.

19. The method of claim 14 , further comprising varying at least one of a width, a pitch, and an angle of the helical structure along an axial length of the cyclonic flow initiator.

Assignees

• Exxonmobil Technology & Engineering Company
• Exxon Mobil Tech And Engineering Company

Inventors

• Urbanski Nicholas F
• Marut Todd P

Classifications

• B01D3/32 Primary

  Other features of fractionating columns {; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30} · CPC title

• F28D1/04

  with tubular conduits {(F28D1/0246 takes precedence)} · CPC title

• B01D1/305

  Demister (vapour-liquid separation) · CPC title

• B01D1/04 Primary

  Evaporators with horizontal tubes · CPC title

• B01D45/16

  generated by the winding course of the gas stream {, the centrifugal forces being generated solely or partly by mechanical means, e.g. fixed swirl vanes} · CPC title