Superheating atomizing steam with hot FCC feed oil

• US 20010000600A1
• Filed: 12/13/2000
• Published: 05/03/2001
• Est. Priority Date: 08/26/1999
• Status: Active Grant

• Current Assignee: Dean C. Draemel, George A. Swan, Jackson I. Ito, Leonard Schoenman, Teh C. Ho
• Original Assignee: Dean C. Draemel, George A. Swan, Jackson I. Ito, Leonard Schoenman, Teh C. Ho
• Inventors: Swan, George A., Ho, Teh C., Draemel, Dean C., Ito, Jackson I., Schoenman, Leonard
• Granted Patent: US 6,352,639 B2
• Time in Patent Office: Days
• US Class Current: 208/113
• CPC Class Codes: B01J 19/26 Nozzle-type reactors, i.e. the distribution of the initial reactants within the reactor is effected by their introduction or injection through nozzles
• CPC Class Codes: B01J 2219/00092 Tubes
• CPC Class Codes: B01J 2219/00094 Jackets
• CPC Class Codes: B01J 2219/00119 Heat exchange inside a feeding nozzle or nozzle reactor
• CPC Class Codes: B01J 2219/00123 adding a temperature modifying medium to the reactants
• CPC Class Codes: B01J 2219/00159 controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling
• CPC Class Codes: B01J 8/1827 the fluidising gas being a reactant
• CPC Class Codes: B05B 7/0433 with one inner conduit of gas surrounded by an external conduit of liquid upstream the mixing chamber
• CPC Class Codes: B05B 7/0483 with gas and liquid jets intersecting in the mixing chamber
• CPC Class Codes: C10G 11/18 according to the "fluidised-bed" technique
• CPC Class Codes: F28C 3/06 the heat-exchange media being a liquid and a gas or vapour temperators for cooling steam F22
• CPC Class Codes: F28F 13/08 by varying the cross-section of the flow channels
• CPC Class Codes: F28F 7/02 Blocks traversed by passages for heat-exchange media F28D7/0008 takes precedence

Abstract

An atomizing gas, such as steam, and a hot fluid comprising a hot liquid to be atomized, are passed under pressure, through separate fluid conduits in a heat exchange means, in which the hot liquid heats the steam to a superheat temperature, by indirect heat exchange. The superheated steam is then injected into the hot fluid, which comprises a two-phase fluid comprising steam and the hot liquid, subsequent to the superheated steam injection. The two-phase fluid is passed through an atomizing means, such as an orifice, into a lower pressure atomizing zone, which causes the steam to expand and atomize the liquid into a spray of liquid droplets. The two-phase fluid is formed before or as a consequence of the superheated steam injection and is preferably steam-continuous when passed through the atomizing means. This process is useful for atomizing a hot feed oil for a fluid cat cracking (FCC) process.

Claims

1. A fluid cat cracking process which comprises the steps of:

(a) injecting steam into a flowing, hot, liquid FCC feed oil under pressure, to form a two-phase fluid comprising said hot oil and steam;

(b) passing an atomizing gas comprising steam and said hot, two-phase fluid formed in (a) through separate conduits in a heat exchange means, in which said flowing hot fluid heats said steam to a superheat temperature, by indirect heat exchange with said fluid;

(c) injecting superheated heated steam formed in (b) into said hot fluid to increase the surface area of said liquid phase and form a steam-continuous two-phase fluid;

(d) passing said steam-continuous fluid through an atomizing means into a lower pressure atomizing zone to atomize said fluid and form a spray comprising droplets of said feed oil, and

(e) passing said spray into a cat cracking reaction zone.

2. A process according to

claim 1

wherein said superheated steam formed in (b) is injected into said fluid in one or more of (i) upstream of said means, (ii) downstream of said means and (iii) in said means.

3. A process according to

claim 2

wherein said superheated steam is injected into said fluid at a Mach number of at least 0.5.

4. A process according to

claim 3

wherein said atomizing means is located downstream of said heat exchange means.

5. A process according to

claim 4

wherein said spray is fan-shaped.

6. A process according to

claim 2

wherein said heat exchange means includes atomizing means.

7. A process according to

claim 2

wherein said heat exchange means includes means for mixing said two-phase fluid flowing therethrough.

8. A process according to

claim 7

wherein said two-phase fluid mixed in said heat exchange means is steam continuous.

9. A process according to

claim 8

wherein said steam heated in said heat exchange means and then injected into said fluid is at a Mach number of at least 0.5.

10. A process according to

claim 2

wherein said heat exchange means comprises part of an FCC feed injection unit which injects said atomized hot oil spray into said cat cracking reaction zone.

11. A liquid atomization process in which a hot fluid comprising the liquid to be atomized flows through a heat exchange means, in indirect heat exchange with an atomizing gas to heat said gas, wherein said hot gas is injected into said flowing hot fluid which comprises a hot, two-phase fluid comprising said gas and liquid, subsequent to said gas injection, to reduce the surface area of said liquid and assist in atomizing said liquid in said fluid into a spray comprising drops of said liquid.

12. A process according to

claim 11

wherein said two-phase fluid comprises a gas continuous fluid, which is atomized by passing it through an atomizing means and into a lower pressure atomizing zone, to form said spray.

13. A process according to

claim 12

wherein said fluid flowing through said heat exchange means comprises a single liquid phase.

14. A process according to

claim 12

wherein a two-phase fluid comprising said liquid to be atomized and said atomizing gas flows through said heat exchange means.

15. A process according to

claim 11

wherein said two-phase fluid is formed either before injecting said heated gas into said fluid, or as a consequence of injecting said heated gas into said fluid.

16. A process according to

claim 15

wherein said two-phase fluid comprises a gas-continuous, two-phase fluid after injecting said hot gas into said fluid.

17. A process according to

claim 15

wherein said heat exchange means includes means for mixing said two-phase fluid flowing therethrough.

18. A process according to

claim 16

wherein said heat exchange means includes means for mixing said two-phase fluid flowing therethrough.

19. A process according to

claim 11

wherein said gas heated in said heat exchange means and then injected into said fluid is at a Mach number of at least 0.5.

20. A process according to

claim 16

wherein said gas heated in said heat exchange means and then injected into said fluid is at a Mach number of at least 0.5.