Tuyere for a basic oxygen furnace

Patent metadata

Field	Value
Publication number	US-11155890-B2
Application number	US-201916514122-A
Country	US
Kind code	B2
Filing date	Jul 17, 2019
Priority date	Jul 17, 2019
Publication date	Oct 26, 2021
Grant date	Oct 26, 2021

Abstract

A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle Θ from 30° to 60° connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

First claim

The invention claimed is:

1. A tuyere comprising:
an inner tube including a lower section having a first diameter, an upper section having a second diameter that is smaller than the first diameter, and a converging transition section having a converging angle Θ from 30° to 60° connecting the inner tube lower section to the inner tube upper section, the inner tube terminating in an inner nozzle at a downstream end of the inner tube upper section;
an outer tube surrounding the inner tube so as to create an annulus therebetween, the outer tube including a lower section having a third diameter that is larger than the first diameter, an upper section having a fourth diameter that is smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the outer tube lower section to the outer tube upper section, the outer tube terminating in an outer nozzle at a downstream end of the outer tube upper section;
a first inert gas valve configured to supply an inert gas to the inner tube and a fuel valve configured to supply a fuel to the inner tube;
a second inert gas valve configured to supply an inert gas to the outer tube and an oxidant valve configured to supply an oxidant to the outer tube; and
a controller programmed to operate the tuyere in a stirring mode or a burner mode, wherein in the stirring mode the first inert gas valve and the second inert gas valve are open while the fuel valve and the oxidant valve are closed, and wherein in the burner mode the fuel valve and the oxidant valve are open while the first inert gas valve and the second inert gas valve are closed;
wherein the tuyere is operable in two modes, a stirring mode in which a jet formed by the tuyere is in the jetting mode with an expansion Mach number from 0.75 to 2 and a burner mode in which a stable non-premixed flame is formed to enable clearing of any blockage of the inner nozzle or the outer nozzle.

2. The tuyere of claim 1 , wherein the expansion Mach number is from 1.25 to 2 when the tuyere is operated in the jetting mode during stirring mode.

3. The tuyere of claim 1 , further comprising:
a pair of diametrically opposed wires spirally wound around on outer surface of the upper section of the inner tube at a taper angle from 15° to 75°.

4. The tuyere of claim 1 , further comprising:
a first pressure sensor in a conduit upstream of the inner tube of the tuyere configured to send a signal to the controller indicative of a first back-pressure in the inner tube of the tuyere; and
a second pressure sensor in a conduit upstream of the outer tube of the tuyere configured to send a signal to the controller indicative of a second back-pressure in the outer tube of the tuyere;
wherein the controller is programmed to switch tuyere operation from the stirring mode to the burner mode when one or both of the first back-pressure and the second back-pressure deviates from a predetermined normal range of back-pressure in the tuyere.

5. The tuyere of claim 1 , further comprising:
a temperature sensor configured to send a signal to the controller indicative of a temperature in the upper section of the outer tube of the tuyere;
wherein the controller is programmed to switch tuyere operation from the stirring mode to the burner mode when the temperature deviates from a predetermined normal range of temperature in the tuyere.

6. The tuyere of claim 1 , further comprising:
a camera configured to send a visual image of the inner nozzle and the outer nozzle of the tuyere to the controller;
wherein the controller is programmed to switch tuyere operation from the stirring mode to the burner mode when the visual image indicates partial blockage of one or both of the inner nozzle and the outer nozzle.

Assignees

• Air Prod & Chem

Inventors

• Makwana Anandkumar
• Sane Anup Vasant
• Buzinski Michael David
• Buragino Gregory J

Classifications

• C21C5/48 Primary

  Bottoms or tuyéres of converters · CPC title

• F27D2003/165

  the fluid being a fuel · CPC title

• F27D2003/167

  the fluid being a neutral gas · CPC title

• C21C5/35 Primary

  Blowing from above and through the bath · CPC title

• F27D3/16

  Introducing a fluid jet or current into the charge (F27D3/18 takes precedence) · CPC title