Tower bottoms coke catching device

Patent metadata

Field	Value
Publication number	US-10696906-B2
Application number	US-201816124322-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Sep 29, 2017
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A coke catching apparatus for use in hydrocarbon cracking to assist in the removal of coke and the prevention of coke build up in high coking hydrocarbon processing units. The apparatus includes a grid device for preventing large pieces of coke from entering the outlet of the process refining equipment while lowing small pieces of coke to pass through and be disposed of. The coke catching apparatus can be easily disassembled to be removed from the refining process equipment and cleaned.

First claim

We claim:

1. A coke catching apparatus that assists in the removal of coke and prevention of coke build up in a reactor unit used in the refining of petroleum products, the coke catching apparatus comprising:
a grid device constructed of a bottom plate, a first section of a grid portion positioned proximate the bottom plate, a second section of the grid portion positioned proximate the first section of the grid portion, and a top hat positioned proximate the second section of the grid portion, the grid portion defined by bars interconnected to create openings therebetween,
the grid device positioned within the reactor unit and proximate to an outlet of the reactor unit, the bottom plate of the grid device fitting over the outlet,
the openings of the grid portion of the grid device sized to allow small pieces of coke contained in petroleum fluid within the reactor unit to pass through to the outlet while preventing large pieces of coke contained in the petroleum fluid from passing through when the petroleum fluid flows into the grid device and to the outlet.

2. The coke catching apparatus of claim 1 wherein the diameter of the grid device is at least 2 inches larger than the diameter of the outlet.

3. The coke catching apparatus of claim 1 wherein the grid device has a bottom plate that is solid and includes a plurality of drain holes to allow for refined product to exit the reactor unit.

4. The coke catching apparatus of claim 1 wherein the top hat is designed to prevent coke particles from settling on top of the coke catching apparatus.

5. The coke catching apparatus of claim 4 wherein the top hat is separated by at least 12 inches from the second section of the grid portion.

6. The coke catching apparatus of claim 1 wherein the openings of the grid device are at least 4 inches wide.

7. The coke catching apparatus of claim 1 wherein the reactor unit is a resid hydrotreating unit.

8. A coke catching device positioned inside a reactor unit that refines a petroleum fluid, the coke catching device comprising:
a bottom section having a bottom plate with a plurality of apertures therein, the bottom section positioned inside the reactor unit adjacent an outlet thereof;
a tubular grid section having a tubular grid constructed of interconnected bars that form openings therebetween, the tubular grid section being connected to the bottom section; and
a top section having a hat portion that is connected to the tubular grid section, each of the top section, the tubular grid section, and the bottom section in combination defining a fluid pathway through one or more of the openings of the tubular grid of the tubular grid section, into an inner portion of the tubular grid, through one or more of the plurality of apertures of the bottom plate of the bottom section and into the outlet of the reactor unit.

9. The coke catching device of claim 8 wherein the openings of the tubular grid of the tubular grid section are sized to permit at least some spalled coke pieces to pass therethrough and along the fluid pathway.

10. The coke catching device of claim 9 wherein the plurality of apertures in the bottom plate of the bottom section are sized to permit the at least some spalled coke pieces to pass therethrough into the outlet of the reactor unit.

11. The coke catching device of claim 8 wherein the openings of the tubular grid of the tubular grid section have a size that retains large spalled coke pieces on an outer side of the tubular grid, the large spalled coke pieces defined as those spalled coke pieces that do not fit through the openings in the tubular grid.

12. The coke catching device of claim 8 wherein the hat portion of the top section is connected to the tubular grid section through a plurality of hat supports that permit at least some spalled coke pieces to pass therebetween.

13. The coke catching device of claim 8 wherein the top section and the tubular grid section are removably connected through a clamp.

14. The coke catching device of claim 8 wherein the reactor unit is a resid hydrotreating unit.

15. A method of catching spalled coke inside a reactor unit that refines a petroleum fluid, the method comprising:
operating a reactor unit with a coke catching device positioned proximate an outlet of the reactor unit, the coke catching device including a bottom section disposed adjacent the outlet, a tubular grid section connected to the bottom section and constructed of interconnected bars that form openings therebetween, and a top section connected to the tubular grid section, the coke catching device providing a fluid pathway through one or more of the openings in the tubular grid section, into an inner portion of the tubular grid section, through the bottom section, and into the outlet;
flowing the petroleum fluid having spalled coke therein through at least a portion of the reactor unit and into the coke catching device through the openings in the tubular grid section thereof;
retaining large coke pieces on an outer side of the tubular grid section, the large coke pieces defined as those coke pieces that do not fit through the openings of the tubular grid section; and
permitting coke pieces that fit through the openings of the tubular grid section to flow with the petroleum fluid along the fluid pathway.

16. The method of claim 15 further comprising operating the reactor unit to create thermal cycling therein and to thereby cause coke in the reactor unit to spall off interior walls thereof.

17. The method of claim 15 further comprising disconnecting the top section, the tubular grid section and the bottom section from each other during a shutdown of the reactor unit.

18. The method of claim 15 further comprising removing the top section, the tubular grid section and the bottom section from inside the reactor unit during a shutdown of the reactor unit.

Assignees

• Marathon Petroleum Co Lp

Inventors

• Cantley Gregory A
• Vail Ross
• Yaden Kathleen
• Brooks Ray

Classifications

• C10G9/18

  Apparatus · CPC title

• B01J8/008

  Details of the reactor or of the particulate material; Processes to increase or to retard the rate of reaction (B01J8/0285, B01J8/067, B01J8/087, B01J8/1836 take precedence) · CPC title

• C10G2300/4031

  Start up or shut down operations · CPC title

• C10G2300/1077

  Vacuum residues · CPC title

• C10G2300/107

  Atmospheric residues having a boiling point of at least about 538 °C · CPC title