US3826479A

US3826479A - Tuyere for a melting furnace

Info

Publication number: US3826479A
Application number: US00333314A
Authority: US
Inventors: K Ikegawa
Original assignee: Kurimoto Ltd
Current assignee: Kurimoto Ltd
Priority date: 1973-02-16
Filing date: 1973-02-16
Publication date: 1974-07-30
Anticipated expiration: 1991-07-30

Abstract

A tuyere for a melting furnace, which comprises inner and outer walls forming a water cooling space therebetween; a cylindrical intermediate wall dividing the water cooling space into an inner water cooling chamber and an outer water cooling chamber, wherein water is introduced into the outer water cooling chamber from the outside of the furnace, circulated into the inner water cooling chamber from the inner end portion at the furnace side of the outer water cooling chamber and discharged from the outer end portion of the inner water cooling chamber; and a guide wall disposed in the water cooling chambers, whereby water circulates at a high speed at least in the portions of the water cooling chambers which are disposed inside the melting furnace.

Description

United States Patent [191 Ikegawa [11] 3,826,479 [451 Ju1y30, 1974 TUYERE FOR A MELTING FURNACE [75] Inventor: Kiyohiro lkegawa, Nara, Japan [73] Assignee: Kurimoto Iron Works, Ltd.,

Osaka-fu, Japan [22] Filed: Feb. 16, 1973 [21] Appl. No.: 333,314

[52] US. Cl. 266/41, 110/1825 [51] Int. Cl C21b 7/16 [58] Field of Search 239/1323; 122/66;

[56] References Cited UNITED STATES PATENTS 2.735,4()9 2/1956 Aurin ct a1 266/41 3,052,219 9/1962 Huuck 122/66 3.599.951) 8/1971 Tundcr..... 266/41 3,627,296 12/1971 Ucrlichs.... 266/41 3,638,929 2/1972 Brulhet 266/41 FOREIGN PATENTS OR APPLICATIONS 77.366 9/1954 Netherlands 239/1323 Primary Examiner-Gerald A. Dost Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn [57] ABSTRACT A tuyere for a melting furnace, which comprises inner and outer walls forming a water cooling space therebetween; a cylindrical intermediate wall dividing the water cooling space into an inner water cooling chamber and an outer water cooling chamber, wherein water is introduced into the outer water cooling chamber from the outside of the furnace, circulated into the inner water cooling chamber from the inner end portion at the furnace side of the outer water cooling chamber and discharged from the outer end portion of the inner water cooling chamber; and a guide wall disposed in the water cooling chambers, whereby water circulates at a high speed at least in the portions of the water cooling chambers which are disposed inside the melting furnace.

2 Claims, 10 Drawing Figures PATENTEB M30374 SHEEI 1 [IF 4 PATENTEM L 3.828.478

sum n or 4 FIG. 8

TUYERE' FOR A MELTING FURNACE- BACKGROUND OF THE INVENTION This invention relates to a tuyere for a melting furnace, especially for a blast furnace.

Since hot air is blown at a high temperature into the furnace from the tuyere of the melting furnace, especially a blast furnace, and the portion of the tuyere projecting inside the furnace is exposed to the molten metal at high temperatures, the fuel burning in the furnace, etc., the tuyere must be forcibly cooled. In addi-' tion to this, since hot air blown from the tuyere into the furnace must be supplied while maintaining its high temperature, care should be taken not to cool excessively the inside of the tuyere.

Hithereto, however, it has notbeen possible to provide a tuyere which sufficiently fulfils the above mentioned two conditions, namely, the cooling water should be smoothly circulated without causing any stagnation to sufficiently cool the tuyere to thereby prevent early breakage of the tuyere while the blown hot air should be maintained at a high temperature. The conventional tuyere has another defect in that it ordinarily comes to the end of its life within three to five months.

SUMMARY OF THE INVENTION Therefore, this invention provides a tuyere which can overcome the above mentioned defects of the conventional tuyere, namely, it can fulfil the above mentioned two conditions and have a long service life.

It is an object of this invention to provide a tuyere for a melting furnace, which comprises inner andouter walls forming a water cooling space therebetween, and an intermediate wall disposed in said water cooling space to divide the same into two inner and outer water cooling chambers, whereby cooling water is initially introduced into the outer water cooling chamber and then circulated to the inner water cooling chamber, to thereby supply cooling water at a low temperature to the inside of the outer wall which is exposed to the highest temperature of the tuyere so that said outer wall is effectively cooled and prevented from early breakage by hot temperatures.

It is another object of this invention to provide a tuyere for a melting furnace, which further comprises a helical guide wall disposed in the outer water cooling chamber to form a helical passage therein, whereby the cooling water introduced into the outer water cooling chamber and passing through said helical passage circulates at a high speed at the vicinity of the top portion of the tuyere which must be most effectively cooled, so that the vicinity of said top portion is effectively cooled and the loss of head of the cooling water is minimized.

It is a still further object of this invention to provide a tuyere for a melting furnace, wherein the vicinity of the top portion of the tuyere is cooled by cooling water passing through the helical passage in the water cooling chamber at a high hydraulic pressure and at a high speed while the water cooling chamber of the rear portion of the tuyere is suppled with another cooling water at a low speed, whereby said rear portion is prevented from being cooled excessively.

It is a still further object of this invention to provide a tuyere for a melting furnace, which can be easily manufactured by welding the required portions of the components, that is, hollow annular base member, an inner wall, an outer wall, an intermediate wall and an edge wall, to thereby form an integrally assembled tuyere.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a central longitudinal sectional view of an embodiment of this invention;

FIG. 2 is a sectional view taken along the line II II of FIG. 1;

FIG. 3 is a sectional view taken along the line III III of FIG. 1;

FIG. 4 is a sectional view taken along the line IV IV of FIG. 1;

FIG. 5 is a sectional view taken along the line of V V of FIG. 1;

FIG. 6 is a central longitudinal sectional view of another embodiment of this invention and which is taken along the line VI VI of FIG. 7',

FIG. 7 is an end view of the tuyere taken from the left end in FIG. 6;

FIG. 8 is a sectional view taken along the line VIII VIII of FIG. 6;

FIG. 9 is a sectional view taken along the line IX IX of FIG. 6;

FIG. 10 is a sectional view taken along the line X X of FIG. 6 and which is simplified so as to be easily understood.

DETAILED DESCRIPTION OF THE INVENTION in FIG. 2, the space inside the base member 1 is divided by a pair of radial partitions 6 into a lower chamber 19 and an upper chamber 20, the

chambers

19 and 20 having respectively inlet ports 7 for receiving water and an outlet port 8 for discharging water at the rear walls thereof (namely, the left side wall in FIG. 1) and having arcuate passages 9 and 10 at the forward wall thereof. These passages 9 and 10 are adapted to be connected respectively to an outer helical passage 13 and an inner helical passage 14 described hereinafter.

The forward wall of the base member 1 (namely, the right side wall in FIG. I) is attached to the rear end surface of a inner wall 2 composed of a tapered cylindrical thick steel pipe by a weld 24.

An intermediate wall 5 composed of a steel plate or a copper plate is provided at each of the outer and inner sides thereof with

helical guide walls

11 and 12 which are pitched at shorter spaces as they approach the forward side (namely, right side in FIG. 1) of the tuyere, and is attached at the top portion thereof to a circular partition 22 by welding; The radii of the inner round surfaces of the inner guide wall 12 and the partition 22 are equal to the outer radius of the corresponding portion of the inner wall 2 while the radii of the outer round surfaces of the outer guide wall 11 and the partition 22 are equal to the inner radius of the corresponding portion of the outer wall 3.

As is shown in FIG. 4, an inclined partition 15 is attached to the front surface of the partition 22. The front surface of the partition 15 is adapted to be in contact with the inner surface of an end wall 4 described hereinafter. An outlet port 17 is provided at the outer side of the partition 15 while a passage 18 is provided at the inner side of the same. These

openings

17 and 18 are adapted to be connected to

helical passages

13 and 14 which will be mentioned hereinafter.

The intermediate wall 5 as mentioned hereinabove is fitted to the outside of the inner wall 2 and the rear end portion of the wall 5 is attached to the forward wall of the base member 1 by welding the portion 23. Accordingly, the inner round surface of the guide wall 12 is closely in contact with the outer round surface of the inner wall 2 to thereby form the inner helical passage 14 therebetween. And the rear end portion of the passage 14 being connected to the passage of the base member 1.

Further, the outer wall 3 in the form of a tapered cylinder and composed of a thick steel plate is fitted to the outside of the intermediate wall 5. The rear end surface thereof is attached to the forward side wall of the base member 1 by the weld 25. Accordingly, the outer round surface of the guide wall 11 is closely in contact with the inner round surface of the outer wall 2 to thereby form the outer helical passage 13 between these walls. The inlet portion 16 (FIG. 5) at the rear end of the passage 13 is connected to the passage 9 of the base member 1.

Further, the annular end wall 4 is attached to the front surfaces of said inner wall 2 and said outer wall 3 respectively by the

welds

26 and 27. The end wall 4 is composed of a thick copper plate and has been manufactured in advance to a predetermined shape by machinery such as a lathe. As is mentioned hereinbefore, a passage 21 partitioned by the partition is formed between the end wall 4 and the partition 22, where cooling water changes its course from the outer helica passage 13 to the inner helical passage 14.

Now referring to the circulation flow of cooling water in the above mentioned embodiment of this invention, cooling water is supplied from a feed pipe (which is not shown in the drawings) through the inlet ports 7 to the lower chamber 19 of the base member 1 and, then, is passed from the passage 9 at the side wall of the lower chamber 19 to the outer helical guide passage 13. In the passage 13, cooling water is circulated along the guide wall 11 to cool the portion of the outer wall 3 which portion is exposed to the inside of the furnace. Then, the cooling water is directed through the outlet port 17 to the passage 21 to cool the end wall 4 and it passes through the passage 18 to the inner helical passage 14. In the passage 14, the cooling water is circulated along the guide wall 12 to cool the inner wall 2 and, then, it flows through the passage 10 into the upper chamber 20 of the base member 1. Thus, the cooling water is discharged from the outlet port 8 to a discharge pipe (which is not shown in the drawings);

connected thereto.

In the above described circulation flow of cooling water, cooling water is circulated in the outer helical passage 13 to cool the outer wall 3 and thereafterjt flows into the inner helical passage 14, to thereby cool the inner wall 2 but to a higher temperature than it cools the outer wall 3. Therefore, the inner wall 2 is cooled to a suitable extent and there is not any risk that the hot air passing through the tuyere will be cooled excessively.

Since the pitch of the guide wall 11 is made smaller as it advances to the forward end of the tuyere, the width of the helical passage 13 gradually becomes narrower in a direction toward the forward end. Therefore, when the cooling water flows into the passage 13, its flowing velocity increases and it circulates at a high speed to cool the outer wall 3 so that the portion of the outer wall 3 projecting into the inside of the furnace and therefore being exposed to a high temperature is sufficiently cooled. Cooling water which has passed through the passage 13 as described hereinbefore flows at a higher speedin the passage 21 which is formed along the end wall 4 and is narrower than the passage 13. Thus, the end wall 4 which is exposed to the highest temperature is also sufficiently cooled. Accordingly, the portion of the outer wall '3 which extends inside the 'fumace and the edge wall 4 are sufficiently cooled and therefore'the breakage of these portions is very decreased to such an extent that it is not necessary to renew the tuyere even after seven months service. Fur ther, it will be easy to design a cooling means of the tuyere in accordance with the condition of the furnace, because the flowing'velocity of cooling water can be optionally adjusted by modifying the widths of the passages l3 and 21.

The tuyere as mentioned hereinbefore may be assembled by attaching to the base member 1, by welding, the inner wall 2, the intermediate wall 5 and the outer wall 3 in this order, and thereafter attaching the end wall 4 to the end portions of the inner wall 2 and the outer wall 3 by welding. The

guide walls

11 and 12, the

partitions

15 and 22, etc., which are necessary to form the

passages

13, 14, 21, etc., will have been attached beforehand to the intermediate wall 5 by welding. Since, therefore, the

guide walls

11 and 12 and the

partitions

15 and 22 respectively are closely in contact with the corresponding surface portions of the inner wall 2, outer wall 3 and end wall 4 only by attaching the intermediate wall 5 and the outer wall 3 to the base member 1 by welding, with a result that the

helical passages

13 and 14, passage 21, etc are formed, it is very easy to manufacture each component and to assemble the same.

Although, in the above mentioned embodiment of this invention, the

helical passages

13 and 14 are formed at both of the outside and inside of the intermediate wall 5 and throughout from the forward end to the rear end thereof, it is sufficient to provide the helical passage 13 only at the outside of the wall 5 and, if desired, only at the front end thereof.

FIG. 6 to FIG. 10 show another embodiment of this invention.

In FIG. 6, a hollow annular base member 31 is composed of a copper casting or a steel casting. To the forward end of the base member 31, an inner wall 32 and an outer wall 33 each having a cylindrical form and composed of a material such as copper are integrally attached to form a rear water cooling chamber 53 therebetween. The forward end portion of the water cooling chamber is closed with a partition 54. And a forward member 34 composed of a material such as copper is integrally attached to said forward end portion. The forward member 34 is provided with an annular concavity which forms a forward water cooling chamber. At the forward position of this chamber, a partition 52 is secured. Further, a cylindrical intermediate wall 35 is provided between the

partitions

52 and 54 to divide the forward water cooling chamber into inner and outer water cooling chambers. As is shown in FIG. 9, to the front surface of the partition 52, an inclined partition 45 is attached, the front surface of which partition 45 is closely in contact with the inner surface of the forward member 34. An outlet port 47 is provided outside the partition 45 while a passage 48 is provided inside the same.

Further, a helical guide wall 41 is provided outside the intermediate wall 35 and between the

partitions

52 and 54 to thereby form a helical passage 43, the forward side of which passage 43 is connected through the outlet port 47 to the passage 51 in front of the partition 52. The rear side of the passage 43 is connected through an opening in the partition 54 to a water supply pipe 39 which is connected through the rear water cooling chamber 53 to the inlet port 37 formed in the base member 31.

To the inner water cooling chamber 55 of the front water cooling chamber, a drainage pipe 40 is connected through an opening formed in the partition 54. The pipe 40 is connected to the outlet port 38 formed in the base member 31 while the forward side of the inner water cooling chamber 55 is connected through the passage 48 to the passage 51. At the rear end portion of the base member 31, an inlet port 56 and an outlet port 57 are provided, each of which is connected to the rear water cooling chamber 53. The inlet port 56 is connected to the water supply pipe 58 to open the top end thereof to the vicinity of the forward portion of the water cooling chamber 53.

According to the above mentioned construction, the

cooling water for cooling the forward water cooling chamber is supplied through the following course; inlet port 37 water supply pipe 39 helical passage 43 outlet port 47 passage 51 passage 48 inner water cooling chamber 55 drainage pipe 40 outlet port 38, and thereafter is discharged from a drainage pipe (not shown) connected to the outlet port On the other hand, the cooling water which is supplied through the inlet port 56 to the water supply pipe 58 flows in the rear water cooling chamber 53 to fill the same and thereafter is discharged from the outlet port 57.

In this embodiment, the cooling water is circulated in two separate courses, namely, one course of the cooling water is circulated from the inlet port 37 and through the circular" passage 51 and thereafter discharged from the outlet port 38 while the other course is circulated from the inlet port 56 and through the rear water cooling chamber 53 and thereafter discharged from the outlet port 57. According to this embodiment, the cooling water is supplied to the forward water cooling chamber is at a high pressure and a high speed, for the purpose of effectively cooling the vicinity of the top portion of the tuyere which is exposed to the highest temperature. On the other hand, since the temperature of hot air decreases if excessive cooling is applied, the rear water cooling chamber 53 should be cooled while preventing such an excessive cooling condition. However, by the above mentioned embodiment, cooling water can be supplied to the rear water cooling chamber 53 at a lower pressure and a lower speed than it is supplied to the forward water cooling chamber, to thereby carry out an effective cooling.

Further, since cooling water supplied to the forward water cooling chamber is circulated through the helical passage 43 and the circular passage 51 to the inner water cooling chamber 55, there is not caused any hold-up of water current, and the cooling water can be circulated at a high speed with little loss in head. Thus the top portion of the tuyere which is exposed to the highest temperature can be effectively cooled. The cooling water can be also circulated at an optional speed by varying the sectional area of the passage 43, etc. Further, even if the top portion of the tuyere is broken to cause the leakage of water at the forward water cooling chamber, the operation can be carried on by maintaining the circulation of water to the rear water cooling chamber 53.

' While all components are attached together by welding in the above mentioned embodiments of this invention, they may be attached together by any other conventional means and the jointed portions may vary other than the jointed portion mentioned hereinbefore. It will be obvious to those skilled in the art that various modifications of the present invention may be resorted to in a manner limited only by a just interpretation of the following claims.

I claim:

1. Atuyere for-a melting furnace comprising inner and outer walls forming a water cooling chamber therebetween, a partitiondisposed at a position near the furnace side of said water cooling chamber to divide the chamber into a forward water cooling chamber section at the furnace side thereof and a rear water cooling chamber section at the opposite side thereof, a cylindrical intermediate wall having an axis extending in the same direction as those of said inner and outer walls and being disposed in said forward water cooling chamber section to divide the forward chamber section into an inner water cooling zone and an outer water cooling zone, a helical guide wall disposed in said outer water cooling zone to form a helical passage for water, a water supply pipe and a drainage pipe respectively connected to said outer water cooling zone and inner water cooling zone, each pipe extending inside the rear water cooling chamber section, and said rear water cooling chamber section being provided with an inlet port for receiving water and an outlet port for discharging the same.

2. A tuyere as defined in claim 1, in which said inner and outer walls are radially spaced, concentric tubular walls, and said partition is a radially extending annular wall extending between said inner and outer walls.

Claims

1. A tuyere for a melting furnace comprising inner and outer walls forming a water cooling chamber therebetween, a partition disposed at a position near the furnace side of said water cooling chamber to divide the chamber into a forward water cooling chamber section at the furnace side thereof and a rear water cooling chamber section at the opposite side thereof, a cylindrical intermediate wall having an axis extending in the same direction as those of said inner and outer walls and being disposed in said forward water cooling chamber section to divide the forward chamber section into an inner water cooling zone and an outer water cooling zone, a helical guide wall disposed in said outer water cooling zone to form a helical passage for water, a water supply pipe and a drainage pipe respectively connected to said outer water cooling zone and inner water cooling zone, each pipe extending inside the rear water cooling chamber section, and said rear water cooling chamber section being provided with an inlet port for receiving water and an outlet port for discharging the same.