Oxy-fuel burner, ignition and flame control system and method for controlling ignition and flame

Patent metadata

Field	Value
Publication number	US-2024230087-A9
Application number	US-202218277854-A
Country	US
Kind code	A9
Filing date	Mar 1, 2022
Priority date	Mar 2, 2021
Publication date	Jul 11, 2024
Grant date	—

Abstract

An oxy-fuel burner and method of use, having a housing defining an oxidizing-agent supply channel running in the longitudinal direction to the downstream end of the housing, a fuel supply channel likewise running in the longitudinal direction of the housing and an oxidant injector running in the longitudinal direction inside the fuel supply channel as well as an ignition and flame-control electrode inside the oxidizing-agent supply channel, the ignition and flame-control electrode being designed to provide initial ignition of the burner and subsequent control of the flame, and being connectable to a system for automatically controlling burner ignition and flame control.

First claim

1 .- 15 . (canceled)

16 . An oxy-fuel burner adapted to be housed within a wall of a melting furnace, the oxy-fuel burner comprising:
a housing, which defines an oxidizing-agent supply channel running in a longitudinal direction, from an upstream end to a downstream end of the housing and having an oxidizing-agent outlet port at the downstream end of the housing, a fuel supply channel extending in the longitudinal direction of the housing and having a fuel outlet port located at the downstream end of the housing, an oxidant injector extending in the longitudinal direction inside the fuel supply channel and having an oxidant outlet port located at the downstream end of the housing, and an ignition and flame-control electrode extending inside the oxidizing-agent supply channel and adapted to provide initial ignition of the burner and subsequent control of a burner flame, wherein said ignition and flame-control electrode is adapted to be connected to a system for automatically controlling the ignition and flame control of a burner.

17 . The oxy-fuel burner according to claim 16 , wherein the ignition and flame-control electrode is an ionisation electrode.

18 . The oxy-fuel burner according to claim 16 , wherein the oxidant injector is adapted to supply oxidant at a subsonic velocity.

19 . The oxy-fuel burner according to claim 16 , in which the oxidant injector is adapted to supply oxidant at a supersonic velocity.

20 . The oxy-fuel burner according to claim 19 , wherein the oxidant injector is equipped with a de Laval nozzle.

21 . The oxy-fuel burner according to claim 16 , wherein the concentration of oxygen in the oxidant introduced through the oxidant injector is higher than the concentration of oxygen in the oxidizing agent introduced through the oxidizing-agent supply channel.

22 . The oxy-fuel burner according to claim 16 , wherein the fuel is natural gas.

23 . The oxy-fuel burner according to claim 16 , wherein said burner contains an earth electrode positioned at a distance of 3-4 mm, in a transverse direction, from the ignition and flame-control electrode, wherein the downstream extremities of the earth electrode and the ignition and flame-control electrode are positioned at an equal distance from the downstream extremity of the housing of the burner.

24 . The oxy-fuel burner according to claim 16 , wherein the distance (L1) from the downstream extremity of the oxygen injector to the downstream extremity of the housing of the burner is equal to the outer diameter (d) of the oxidant injector, while the distance (L2) from the downstream extremity of the ignition and flame-control electrode to the downstream extremity of the housing of the burner is equal to 0.5d.

25 . The oxy-fuel burner according to claim 16 , adapted to be fitted into a tuyere located in the wall of a melting furnace, wherein the distance from the downstream extremity of the housing of the burner to the downstream extremity of the tuyere is between 2D and 3D, where D is the inner diameter of the tuyere.

26 . The oxy-fuel burner according to claim 25 , adapted to be fitted into a tuyere having a blast supply flow rate of 700-1,200 m 3 /hr at a temperature of 250-650° C.

27 . A system for automatically controlling the ignition and flame control of the oxy-fuel burner according to claim 1 , wherein said system comprises: an ignition device; a combustion-signalling device; a cut-off valves unit, designed with the ability to be connected to a gas-oxygen unit which regulates the flows of fuel, oxidizing agent, oxidant and instrument air and supplies same to the burner; and a control unit designed with the ability to communicate with the gas-oxygen unit, the ignition device, the combustion-signalling device and the cut-off valves unit.

28 . The system according to claim 27 , in which the ignition device is a high voltage transformer source.

29 . A method for controlling the ignition and flame control of oxy-fuel burners, fitted in a melting furnace, using the system according to claim 16 , which method comprises steps in which:
a signal is received confirming that the gas-oxygen unit has been switched on; the number of burners requiring to be put into operation is determined; cut-off valves in the cut-off valves unit are opened for the supply of fuel oxidizing agent and oxidant to the selected burners; spark ignition of the selected burners is switched on; spark ignition is switched off; the flame in the burners is monitored, during which monitoring process:
the presence of a flame in each burner is determined, wherein, when a flame is found to be present in all the burners, operation is continued, but if a flame is found to be absent in one or more of the burners, spark ignition is switched on in the corresponding burner;
a tally is maintained of the number of unsuccessful attempts to ignite the burners, wherein, if said number is greater than a specified value, supply of gas, oxidizing agent and oxidant to the corresponding burner is halted.

30 . The method according to claim 29 , in which the specified value of the number of unsuccessful attempts to ignite the burners is equal to five.

Assignees

• Air Liquide

Inventors

• Abutalipov Ayrat
• Chernyshev Ivan
• Leroux Bertrand
• Misyura Maxim
• Shovkan Artem
• Ougarane Lahcen
• Paubel Xavier

Classifications

• F23D14/22 Primary

  with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other · CPC title

• F23N5/123 Primary

  using electronic means · CPC title

• F23L2900/07005

  Injecting pure oxygen or oxygen enriched air · CPC title

• F23L2900/07006

  Control of the oxygen supply · CPC title

• F23D14/32

  using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air (F23D14/38 takes precedence) · CPC title