WO2010151874A2

WO2010151874A2 - Tuyere

Info

Publication number: WO2010151874A2
Application number: PCT/US2010/040190
Authority: WO
Inventors: Elmer Reno; James Benson; Robert Pattillo; Kim Herald
Original assignee: Reno Refractories, Inc.
Priority date: 2009-06-26
Filing date: 2010-06-28
Publication date: 2010-12-29
Also published as: WO2010151874A3

Abstract

A tuyere for use in furnaces having a base section attached to the wall of the furnace and a nose section that extends into the interior of the furnace. The nose section includes an angled or sloped top surface and may include two front side faces that taper inwardly to facilitate passage of the coke or other materials past the tuyere during operation. A passageway extending through the tuyere to introduce air into the interior of the furnace may include multiple sections with the outlet section having a downward angle to prevent air from bouncing back toward the tuyere. In a second embodiment, the tuyere may have a base plate that is attached to the furnace to allow the nose section to be slidingly attached thereto.

Description

This invention claims benefit to U.S. Provisional Patent Application Serial No. 61/220,670, filed June 26, 2009, the entirety of which is hereby incorporated by reference.

Field of the Invention

The invention relates to furnaces for melting iron, copper or other metals and, more particular, to tuyeres for use in furnaces.

Background of the Invention

Cupola furnaces are generally vertical shafts having a refractory lining or material (e.g., bricks) on its interior to permit the melting of iron, copper or other materials. A charge, which typically consists of alternate layers of a metal layer, a coke layer and other materials such as limestone, and ferrous-alloys, is introduced into the top of the furnace. Tuyeres are used to inject air, both heated and non-heated, into furnaces. The air, which is comprised of about 21% oxygen, is used to add extra oxygen into the furnace to increase the reaction with the carbonaceous materials present in the coke or other materials to create heat. The reaction creates temperatures at the end of the tuyeres that may reach 3,400⁰F to 4,000⁰F.

A lot of smaller facilities simply use tubes with larger openings for introducing air into the furnace. The larger openings result in a low blast velocity that decreases the efficiency of the process. In such systems, the air does not properly penetrate the center of the coke bed, thereby resulting in uneven reactions and an inefficient combustion of coke fuel and oxygen. This requires, among other things, the introduction of additional coke fuel into the system to spur the reaction. Furthermore, when air contacts the materials inside the furnace, the air may bounce back and contact the end of the tubes and the inside walls of the furnace. This process, commonly known as back attack phenomenon, causes the refractory lining or material of the furnace walls to erode and fail in a short period of time (often less than 12 hours). Also, because the reactions are taking place near the furnace interior walls, the temperatures and turbulence of the molten materials are elevated, which reduces the refractory's ability to withstand corrosive metal and slag combinations washing along the surfaces. In such cases, the furnace must be shut down, and the excess material must be cleared through doors at the bottom of the furnace to permit the furnace walls to be repaired or replaced. The short operation time for the furnace leads to wasted material and more down time. This increases the cost of operation due to the use of increased amounts of fuel and decreased efficiency.

Typical tuyeres are tapered cylindrical pipes, usually copper, with hollow sidewalls. Water is circulated through cavities in the hollow sidewalls at a high velocity in order to keep the pipe cool enough to withstand the high temperatures. While the water keeps the copper at a temperature lower than the melting point, the water is extracting heat from the process, thereby lowering the efficiency of the process. The heat extraction represents a significant (likely at least 15%-25%) loss of the energy for the melting process, thereby increasing the cost of the melting process (e.g., requiring more coke fuel to react with the air) while decreasing the efficiency.

In addition to the increased cost and decreased efficiency set forth above, the presence of water in the system also creates problems. In particular, when tuyeres have defects that allow the cooling water to escape into the furnace, the furnace must be stopped due to safety aspects. Stoppage of the furnace will require remaining workforces downstream to also be stopped, thereby increasing the total cost of such cessation of activity and further decreasing efficiency.

Summary of the Invention

The present invention is an improvement over the prior tuyeres, in one embodiment, in how the design inhibits damage to the tuyere and provides for a more efficient process. In particular, in one embodiment, the tuyere of the present invention comprises a base section that is affixed or otherwise attached to the interior wall of a furnace, and a nose section that extends into the interior of the furnace. The nose section preferably includes an angled or sloped top surface in order to deflect away the coke and other materials that are dropped onto the surface. Two front side faces may also taper inwardly on the nose section to help facilitate movement of the coke or other materials past the nose section.

A passageway through the tuyere allows air to be inserted into the interior of the furnace. In order to prevent air from bouncing back toward the tuyere, the passageway may include a section that is angled downwardly into the furnace. The passageway may have a smaller diameter at its outlet to increase the velocity of the air. The components of the tuyere extending into the furnace are preferably made of a refractory material to inhibit damage to the tuyere during operation.

In another embodiment, the base of the tuyere may include a back plate that is attached to the furnace and a wedge plate that may be slidingly attached thereto. The passageway extends through the back plate, wedge plate and nose section to allow air to be introduced into the furnace. It is therefore an object of the present invention to provide a new and improved tuyere for use in the creation of metals.

Another object of the present invention is to provide a new and improved tuyere that lowers the amount of coal or coke needed.

It is yet another object of the present invention to produce a tuyere that is economical and easy to use.

Still another object of the invention is to provide a tuyere that increases the velocity of the air flowing therethrough.

Yet another object of the invention is to provide a tuyere that increases the efficiency of a furnace.

Another object of the present invention is to provide a tuyere that permits furnaces to operate for much longer periods of time.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts.

Brief Description of the Drawings

Figure 1 is a front perspective view of one embodiment of the tuyere of the present invention.

Figure 2 is a side perspective view of the tuyere of Figure 1.

Figure 3 is a front elevated view of the tuyere of Figure 1.

Figure 4 is a cross sectional view of the tuyere of Figure 3 taken along line A-A.

Figure 5 is a front perspective view of a second embodiment of the tuyere of the present invention. Figure 6 is a cross sectional view of the tuyere of Figure 5 taken along line 6-6. Figure 7 is a side elevated view of the tuyere of Figure 5. Figure 8 is a perspective view of the tuyere of Figure 5.

DETAILED DESCRIPTION OF THE INVENTION

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail several specific embodiments, with the understanding that the present disclosure is to be considered merely an exemplification of the principles of the invention and the application is limited only to the appended claims.

Referring now to the drawings, and particularly to Figs. 1 through 4, there is shown one embodiment of the present invention. The tuyere of the present invention, generally designated by the reference numeral 10, is shown as having a base section 12 and a nose section 14. The tuyere is preferably made of a refractory material to inhibit damage to the tuyere during operation of the furnace.

The base section 12 of the tuyere may be affixed or otherwise attached to the interior wall of a furnace in a known way. The nose section 14 of the tuyere is designed to extend into the interior of the furnace. Extending into the interior of the furnace distances the reaction of the materials within the furnace away from the interior walls to extend the life of the interior walls. In order to deflect the coke and other materials that are dropped into the surface, the nose section 14 preferably includes an angled or sloped top surface 16. In one embodiment, the top surface is sloped at an angle of approximately 60 degrees. Referring now to Figures 1 and 3, the nose section 14 may also include two front side faces 18 that taper inwardly to also facilitate passage of the coke and other dropped materials by the nose section 14 of the tuyere 10.

A passageway 20, having an inlet 30 and an outlet 32, extends through the base section 12 and the nose section 14 of the tuyere 10 to permit air to be inserted from an outside source into the body or interior of a furnace. As shown in Figure 4, the passageway may consist of more than one section 22, 24, wherein the outlet section 24 may be angled downward. The downward angle of the outlet section 24 of the passageway 20 permits any air that exits the passageway 20 into the furnace and "bounces back" toward the tuyere 10 to pass, or be deflected, around the tuyere 10. Because the outlet of the tuyere is away from the interior walls of the furnace, damage or erosion to the interior walls of the furnace will also be inhibited.

Referring again to Figure 4, the outlet 32 of the passageway preferably has a smaller diameter than the inlet 30 to increase the velocity of the air before introduction into the furnace. While the inlet and outlet openings may be sized according to the demands of difference furnaces, in one embodiment, it is appreciated that the inlet section 22 may have a diameter of 4 9/16 inches and the outlet 32 may have a diameter of 3/4 inches.

Referring now to Figure 5 through 8, a second embodiment of the tuyere of the present invention is shown. The tuyere, general designated by the reference numeral 100, is shown having a base 102 and a nose section 104. While the base may be a variety of designs that may be fastened to the walls or structures of the furnace, the embodiment shown in the figures is a two-piece product that permits the tuyere to be slid down into engagement. Particularly, the base shown in Figures 7 and 8 includes a back plate 106 that would fit over hole in side of the furnace structure and a wedge plate 108 that may be slidingly attached thereto. It is appreciated that the back plate 106 of the base may be attached to the furnace wall or other structure in a known way. The nose section 104 includes a neck 110 and a main cylindrical body 112. Extending through the neck and main cylindrical body 112 are one or more passageways 114, 116, that also extends through the base 102 to permit air to be inserted from an outside source into the body or interior of the furnace. In one embodiment the passageway is angled downward to permit any air that exits the passageway into the furnace and "bounces back" toward the tuyere 100 to pass, or be deflected, around the tuyere 100. As shown in Figure 6, one suitable angle is 10 degrees.

The components of the tuyere extending into the furnace are preferably made of a refractory material to inhibit damage to the tuyere during operation of the furnace. While a variety of refractory materials may be used, examples of suitable referactory materials include an aluminum magnesia spinel or a chrome aluminum material. The cylindrical body may also include an expanded metal such as, but not limited to, a stainless steel expanded metal to help retain the refractory material in place. While the inlet and outlet of the passageway may be sized according to the demands of different furnaces, in one embodiment, it is appreciated that the diameter throughout the passageway may be about 4 inches.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is limited only by the scope of the appended claims.

Claims

1. A tuyere for a furnace having walls defining an interior, the tuyere comprising: a base section operatively attached to the furnace walls; a nose section extending into the interior of the furnace, the nose section having a top surface that is angled downwardly; and a passageway through the base section and nose section into the interior of the furnace.

2. The tuyere of claim 1 where the angle of the top surface of the nose section is about 60 degrees.

3. The tuyere of claim 1 where the tuyere is made from a refractory material.

4. The tuyere of claim 1 wherein the passageway has an inlet opening in the base section and an outlet opening in the nose section, wherein the outlet opening has a smaller diameter than the inlet opening.

5. The tuyere of claim 4 wherein the outlet opening is about 3 ¹A inches in diameter.

6. The tuyere of claim 4 wherein the passageway includes a first section proximate the inlet opening and a second section proximate the outlet opening, the second section being angled downwardly.

7. The tuyere of claim 4 wherein the inlet and outlet openings may be sized according to the demands of different furnaces.

8. The tuyere of claim 6 wherein the angle of the second section is approximately 10 degrees.

9. The tuyere of claim 1 wherein the nose section further includes two side faces, wherein the two side faces are angled inwardly.

10. The tuyere of claim 1 where the angle of the top surface of the nose section is about 10 degrees.

11. The tuyere of claim 1 wherein the nose section further comprises an expanded metal wrap.

12. The tuyere of claim 1 wherein the base section includes a back plate and a wedge plate attached to the nose section, wherein the wedge plate slidingly engages the back plate.

13. A tuyere for a furnace having walls defining an interior, the tuyere comprising: a base operatively attached to the furnace walls; a nose positioned within the interior of the furnace and having a downwardly angled top surface; and a passageway through the base section and nose section into the interior of the furnace; wherein the base and nose are made from a refractory material.

14. The tuyere of claim 12 wherein the nose further includes an expanded metal.

15. The tuyere of claim 12 wherein the passageway is angled at about 10 degrees.

16. The tuyere of claim 12 wherein the top surface is angled at about 10 degrees.