Reducing gas injection system

Patent metadata

Field	Value
Publication number	US-12504233-B2
Application number	US-202118043949-A
Country	US
Kind code	B2
Filing date	Sep 27, 2021
Priority date	Sep 28, 2020
Publication date	Dec 23, 2025
Grant date	Dec 23, 2025

Abstract

The injector(s) have a nozzle body with an inner gas channel for guiding reducing gas from an inlet port to injection holes(s). The nozzle body is mounted trough an aperture in the blast furnace wall at a shaft level of the blast furnace and includes a peripheral mounting portion configured for connecting the injector in a gas tight manner to the aperture. The inlet port is in fluidic connection with a reducing gas distribution pipe by means of an injector stock including a feeding pipe connected to the reducing gas distribution pipe, an elbow connected to the feeding pipe and an injector pipe connected to the elbow and being flange mounted in a gas tight manner to the inlet port. The injector pipe and/or an outlet of the elbow have at least one cardan compensation joint.

First claim

The invention claimed is:

1 . A reducing gas injection system for a blast furnace comprising a blast furnace wall, wherein the reducing gas injection system comprises
a reducing gas distribution pipe, one or more injectors mounted to the blast furnace wall at a shaft level, wherein the reducing gas distribution pipe is attached to the blast furnace wall or a supporting structure thereof, wherein said injector(s) comprise(s) a nozzle body with a peripheral wall extending along a longitudinal axis from a front portion, with at least one injection hole, to an opposite rear portion with an inlet port, wherein the nozzle body includes an inner gas channel for guiding reducing gas from said inlet port to said injection holes(s); wherein said nozzle body is mounted through an aperture in said blast furnace wall in such a way that the front portion with the injection hole(s) is located on an inner side of said blast furnace, whereas said rear portion with the inlet port is outside of said blast furnace wall, wherein said nozzle body comprises a peripheral mounting portion configured for connecting said injector in a gas tight manner to said aperture in said blast furnace wall, wherein the inlet port is in fluidic connection with the reducing gas distribution pipe by means of an injector stock, said injector stock comprising a feeding pipe connected to the reducing gas distribution pipe, an elbow connected to said feeding pipe and an injector pipe connected to said elbow, said injector pipe being flange mounted in a gas tight manner to the inlet port of the injector and said injector pipe and/or an outlet of the elbow comprising at least one cardan compensation joint.

2 . The reducing gas injection system as claimed in claim 1 , wherein the at least one cardan compensation joint of said injector pipe is connected to the elbow.

3 . The reducing gas injection system as claimed in claim 1 , wherein the front region of the injection hole(s) is protruding in the inner side of said blast furnace.

4 . The reducing gas injection system as claimed in claim 1 , wherein the feeding pipe comprises one or more further cardan compensation joints.

5 . The reducing gas injection system as claimed in claim 1 , wherein the injector is mounted with a flange in a gas tight manner with bolts or hooks to the aperture in said blast furnace wall.

6 . The reducing gas injection system as claimed in claim 1 , wherein the injector pipe is flange mounted in a gas tight manner with bolts or hooks to the inlet port of the injector, with a metallic and/or soft seal for gas tightness between a first mounting flange on said rear portion on said nozzle body and a second mounting flange on said injector pipe.

7 . The reducing gas injection system as claimed in claim 1 , wherein the injector(s) comprising said nozzle body with said peripheral wall extending along a longitudinal axis from a front portion, with at least one injection hole is made of one piece.

8 . The reducing gas injection system as claimed in claim 1 , wherein the elbow comprises a maintenance and inspection port centered with the longitudinal axis of the injector, to which a cover, a view glass and/or a camera is removably attached.

9 . The reducing gas injection system as claimed in claim 1 , wherein a gas flow detector or a thermocouple is mounted within the injector stock, either protruding in the gas flow or being integrated in a refractory lining of said injector stock.

10 . The reducing gas injection system as claimed in claim 1 , wherein the front portion of the injector is configured to be mounted through an aperture in a cooling plate attached to an inner side of said blast furnace wall.

11 . The reducing gas injection system as claimed in claim 10 , wherein the front portion of the injector is provided with a cooling system, in fluidic cooling connection with a cooling system of the cooling plate.

12 . The reducing gas injection system as claimed in claim 1 , wherein an inner surface of the reducing gas distribution pipe, the injector(s), and the injector stock is lined with a refractory insulating material layer.

13 . The reducing gas injection system as claimed in claim 1 comprising between 20 and 60 injectors.

14 . The reducing gas injection system as claimed in claim 1 , wherein the injector(s) is/are oriented perpendicular or tangentially to the blast furnace wall.

15 . The reducing gas injection system as claimed in claim 1 , wherein the reducing gas distribution pipe is divided in several portions located around the furnace, each portion being supplied by individual reducing gas supply lines.

16 . The reducing gas injection system as claimed in claim 1 , wherein a protruding cover is arranged above the injector(s) and configured to protect the nozzle body front portion that protrudes inside the furnace from a descending burden material.

17 . A blast furnace installation for producing pig iron, comprising a blast furnace and at least one reducing gas injection system as claimed in claim 1 , wherein the injector(s) are mounted at shaft level.

Assignees

• Wurth Paul Sa

Inventors

• Maggioli Nicolas
• Kinzel Klaus Peter
• Kass Gilles

Classifications

• F27D2007/023

  Conduits · CPC title

• F27D2003/169

  Construction of the lance, e.g. lances for injecting particles · CPC title

• F27D2003/166

  the fluid being a treatment gas · CPC title

• F27D3/16

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

• F27B1/16

  Arrangements of tuyeres · CPC title