METHOD AND APPARATUS FOR DECOKING TUBES IN AN OIL REFINERY FURNACE

• US 20080234868A1
• Filed: 03/24/2008
• Published: 09/25/2008
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Leslie D. Osborne
• Original Assignee: Leslie D. Osborne
• Inventors: Osborne, Leslie D.
• Granted Patent: US 8,349,169 B2
• Time in Patent Office: Days
• US Class Current: 700/271
• CPC Class Codes: C10G 9/16 Preventing or removing incrustation
• CPC Class Codes: C10G 9/206 controlling or regulating the tube furnaces
• CPC Class Codes: F28D 2021/0059 for petrochemical plants
• CPC Class Codes: F28G 13/00 Appliances or processes not covered by groups F28G1/00 - F28G11/00; Combinations of appliances or processes covered by groups F28G1/00 - F28G11/00
• CPC Class Codes: F28G 15/00 Details measuring thickness of deposit G01B
• CPC Class Codes: F28G 15/003 Control arrangements

Abstract

A control system for performing a global-decoke of a tube furnace comprising a plurality of passes.

Claims

1. A control system for performing a global-decoke of a tube furnace comprising a plurality of passes, said control system comprising:

a main-controller, wherein said main-controller comprises at least one processor and sufficient memory to perform a control algorithm, wherein the main-controller operates in response to said control algorithm, wherein said main-controller is operably connected to;

a plurality of feed regulators FR(N), a plurality of feed gas regulators FGR(N), a plurality of air regulators AR(N), a plurality of steam regulators SR(N), a plurality of tube temperature measurement devices TT(N), a plurality of output temperature measurement devices OTC(N), and a 3-way valve,

wherein a plurality of feed outlet temperature FOT(N) is respectively monitored by the plurality of output temperature measurement devices OTC(N), a plurality of furnace tube temperatures FTT(N) is respectively monitored by the plurality of tube temperature measurement devices TT(N), a plurality of feed input rates FIR(N) is respectively monitored by the plurality of feed regulators FR(N), and

wherein said main-controller in response to said control algorithm communicates a control signal to the 3-way valve to direct flow output along a combined output line to a decoke system 180 when a predetermined number of the plurality of feed input rates FIR(N) do not meet or exceed a corresponding plurality of set input feed rates SIFR(N) whereupon said main controller 300 performs a global-decoke procedure.

2. A control system for performing a global-decoke of a tube furnace comprising a plurality of passes, said control system comprising:

a main-controller, wherein said main-controller comprises at least one processor and sufficient memory to perform a control algorithm, wherein the main-controller operates in response to said control algorithm, wherein said main-controller is operably connected to;

a plurality of feed regulators FR(N), a plurality of feed gas regulators FGR(N), a plurality of air regulators AR(N), a plurality of steam regulators SR(N), a plurality of tube temperature measurement devices TT(N), a plurality of output temperature measurement devices OTC(N), and a 4-way valve,

wherein a plurality of feed outlet temperature FOT(N) is respectively monitored by the plurality of output temperature measurement devices OTC(N), a plurality of furnace tube temperatures FTT(N) is respectively monitored by the plurality of tube temperature measurement devices TT(N), a plurality of feed input rates FIR(N) is respectively monitored by the plurality of feed regulators FR(N), and

wherein said main-controller in response to said control algorithm communicates a control signal to the 4-way valve to direct flow output along a combined output line to a decoke system 180 when a predetermined number of the plurality of feed input rates FIR(N) do not meet or exceed a corresponding plurality of set input feed rates SIFR(N) whereupon said main controller 300 performs a global-decoke procedure.

3. A control system for performing a global-decoke of a tube furnace comprising a plurality of passes, said control system comprising:

a main-controller, wherein said main-controller comprises at least one processor and sufficient memory to perform a control algorithm, wherein the main-controller operates in response to said control algorithm, wherein said main-controller is operably connected to;

a plurality of feed regulators FR(N), a plurality of feed gas regulators FGR(N), a plurality of air regulators AR(N), a plurality of steam regulators SR(N), a plurality of tube temperature measurement devices TT(N), a plurality of output temperature measurement devices OTC(N), flow regulator BR(1) for directing fluid to a decoke system 180, flow regulator BR(2) in a coke bypass line, and a 4-way valve,

wherein a plurality of feed outlet temperature FOT(N) is respectively monitored by the plurality of output temperature measurement devices OTC(N), a plurality of furnace tube temperatures FTT(N) is respectively monitored by the plurality of tube temperature measurement devices TT(N), a plurality of feed input rates FIR(N) is respectively monitored by the plurality of feed regulators FR(N), and

wherein said main-controller in response to said control algorithm communicates a control signal to the 4-way valve to direct flow output along a combined output line to a decoke system 180 via BR(1) when a predetermined number of the plurality of feed input rates FIR(N) do not meet or exceed a corresponding plurality of set input feed rates SIFR(N) whereupon said main controller 300 performs a global-decoke procedure.

4. A control system for performing a global-decoke of a tube furnace comprising a plurality of passes, said control system comprising:

a main-controller, wherein said main-controller comprises at least one processor and sufficient memory to perform a control algorithm, wherein the main-controller operates in response to said control algorithm, wherein said main-controller is operably connected to;

a plurality of feed regulators FR(N), a plurality of feed gas regulators FGR(N), a plurality of air regulators AR(N), a plurality of steam regulators SR(N), a plurality of tube temperature measurement devices TT(N), a plurality of output temperature measurement devices OTC(N), a main flow meter MFM on a main input line and a 3-way valve,

wherein a plurality of feed outlet temperature FOT(N) is respectively monitored by the plurality of output temperature measurement devices OTC(N), a plurality of furnace tube temperatures FTT(N) is respectively monitored by the plurality of tube temperature measurement devices TT(N), a plurality of feed input rates FIR(N) is respectively monitored by the plurality of feed regulators FR(N), wherein total flow rate TFR into the tube furnace is measured by said main flow meter MFM, and

wherein said main-controller in response to said control algorithm communicates a control signal to the 3-way valve to direct flow output along a combined output line to a decoke system 180 when TFR is less than MATFR whereupon said main controller 300 performs a global-decoke procedure.