US3745943A

US3745943A - Baffle nose tuyere

Info

Publication number: US3745943A
Application number: US00240057A
Authority: US
Inventors: W Nothstein
Original assignee: Bethlehem Steel Corp
Current assignee: Bethlehem Steel Corp
Priority date: 1972-03-31
Filing date: 1972-03-31
Publication date: 1973-07-17
Anticipated expiration: 1990-07-17

Abstract

An improved tuyere which minimizes under nose burning, and which is suitable for blast furnaces is disclosed. The nose section of the tuyere is provided, on its underside, with a slot for the passage of part of the gases flowing through the tuyere and a deflecting means projecting into the tuyere bore for diverting gases into the slot.

Description

O Umted States Patent 11 1 1111 3,745,943 Nothstein July 17, 1973 [54] BAFFLE NOSE TUYERE 1,994,115 3 1935 Stoecker 266/41 2,074,507 3 1937 H 2 4 [75] Inventor: Willard D. Nothstem, Bethlehem, 2,781,190 1957 l l N 22 3,350,084 10/1967 Lucarell 266/41 [73] Assignee: Bethlehem Steel Corporation,

Bethlehem p Primary ExaminerKenneth W. Sprague 2 Filed; Man 31 972 Attorney-Joseph J. OKeefe An improved tuyere which minimizes under nose burn- [52] U.S. CI 1 10/1825, 122/66, 266/41 ing, and which is suitable for blast furnaces is disclosed. [51] Int. Cl. F23c 7/00 The nose section of the tuyere is provided, on its under- [58] Field of Search 110/1825; 266/41; side, with a slot for the passage of part of the gases 122/66 flowing through the tuyere and a deflecting means projecting into the tuyere bore for diverting gases into the [56] References Cited slot.

UNITED STATES PATENTS 8 Claims, 7 Drawing Figures 1,738,901 12/1929 Holzworth 266/41 1,789,870 1/1931 Holzworth .1 266/41 25 1 i 1. mummnz 1 i 20 j T PATENTEDJUL 1 1 1913 BACKGROUND OF THE INVENTION This invention relates to metallurgical apparatus for treating molten material and more particularly to tuyeres.

Tuyeres of the type useful in blast furnace operations are subject to burning out at the nose section. Burning out is caused, or accelerated by, accumulation under the nose due to insufficient or improperly directed agitation of the molten material in the furnace. Various solutions to minimize nose bum-out have been proposed. Early prior art proposals have included constricting the nose bore to change the direction of the tuyere blast, or alternately, locating the tuyere to direct the blast in a more downwardly direction.

Other devices operate by deflecting only a portion of the tuyere blast. For example, notches or grooves have been cut in the underside of the tuyere to cause a portion of the blast to exit under the tuyere. U. S. Pat. No. 1,738,901 to Holzworth, utilizes a second bore with an opening under the tuyere nose through which a portion of the tuyere blast is directed underneath the tuyere nose. Such prior art devices, while solving the problem to some extent, are not entirely satisfactory. Slight adjustments in the angle of the blast are not possible without extensive redesign of the tuyere. Further, changing the quantity or velocity of gases passing through the grooves or alternate bores cannot be readily accomplished.

There has therefore been a need for a tuyere construction which minimizes undernose burning.

Further, there has been a need for an improved means for directing a portion of the tuyere blast so that the agitation of the molten material in the blast furnace discourages buildup, thus reducing nose burning, and thereby prolonging tuyere life.

SUMMARY OF THE INVENTION It is an object of this invention to provide a tuyere with minimum undernose burning.

It is another object of this invention to provide a tuyere with detachable nose section which improves gas flow direction.

It is still another object of this invention to divert part of the tuyere gas flow by means of a nose slot together with an adjustable, detachabledeflecting. means.

The aforementioned prior art deficiences are obviated by the bafile nose tuyere of this invention. The instant tuyere provides an improved nose section comprising a slot for the passage of gases diverted from the main bore, and a deflecting means located in the main bore to direct and regulate the gas flow. The deflecting means, including a baffle plate, cooperates with the main boreand slot so that a precise and easily adjustable volume and velocity of gases may be directed to exit through the slot.

INCORPORATION BY REFERENCE A preferred embodiment utilizes the body portion and nose cooling features of the tuyere disclosed in U. S. Pat. No. 2,891,783, to John E. Eberhardt, filed Apr. 1 l, 1957 and issued June 23, 1959; which is hereby incorporated by reference, and hereinafter referred to as the Eberhardt patent."

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a longitudinal portion of the tuyere of this invention viewed from the underside thereof.

FIG. 2 shows a transverse section of the tuyere taken along line 2-2 of FIG. 1.

FIG. 3 shows a section of the tuyere taken along line 3-3 of FIG. 1 with a wall portion broken away to show the cooling water nozzle.

FIG. 4 shows a longitudinal section of the tuyere with an integrally cast deflector means in the nose portion.

FIG. 5 is a front view of a detachable deflecting means.

FIG. 6 shows a top view of a detachable deflecting means.

FIG. 7 is a side view of a detachable deflecting means.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1, 2, 3, 4, a tuyere, generally designated A, comprising a butt section 12 and nose section 14 is shown. Butt section 12 includes outer wall 16 and inner wall 18, and nose section 14 likewise includes outer wall 20 and inner wall 22. Nose section 14 and butt section 12 are separably joined at 24 below bafi'le wall 25 at the end of butt section 12. The nose section of the tuyere is normally inserted into the hearth sec tion of, for example, a blast furnace with the underside resting in, or close to the molten material in the furnace. Cooling water circulates in annular cooling chambers, generally 26 and 28 which are formed between the inner and outer walls of both butt section 12 and nose section 14. Cooling water nozzle 30 supplies water for these chambers in the manner described in the Eberhardt patent. In nose section 14, inner wall 22 defines, in the nose section, the main bore for the passage of gases through tuyere A. In addition, a slot 36, which extends through nose inner wall 22 and outer wall 20, is provided.

Deflecting means 32 is positioned on nose inner wall 22 of tuyere A and extends into the main bore toward the butt wall of the tuyere from slot 36, as shown in FIGS.3and4.

In FIGS. 5, 6, and 7, the'deflecting means includes baffle plate 38, slot mating face 42, main bore face 44, and tuyere mating face 40; Deflecting means 32, as seen in FIG. 3, is inserted into slot 36 in nose section 14 with slot mating face .42 adjacent slot face 43. The tuyeremating face 40 of deflecting means 32 rests on inner wall 22 of the tuyere. The baffle plate 38 deflects a portion of the gases flowing'through the tuyere main bore through the slot 36 to the underside of the nose section 14. It will be obvious to those skilled in the art that the deflecting means 32 may be integrally cast with nose section 14, if preferred, and baffle plate 38 thus integrally formed will perform in the same fashion as the separabledeflecting means 32 shownin FIGS. 5, 6 and 7. 6

FIG. 4 illustrates gases flowing through tuyere A from butt section 12 through nose section 14 where, in the latter, the gases are baffled by deflecting means 32, causig a portion of the gases to be diverted. The main portion of the gases exit nose section 14 at end 34, while a lesser amount, preferably 10-13 percent or more of the total volume of gases, exit nose section 14 through slot 36.

Deflecting means 32 may be a separable, replaceable part as shown in FIG. 3 or may be integrally cast with nose section 14, as shown in FIG. 4, as noted hereinafter.

Copper, or copper alloys, as disclosed in the Eberhardt patent, are preferred as material of construction for the integrally cast deflecting means. However, other metals such as stainless, are suitable. The detachable deflecting means may be the same metal as the tuyere, or different, and materials such as high alumina ceramics are also within the scope of this invention.

Joining of the baffle means when not integrally cast with the nose section) to the inner wall can be accomplished by silver soldering, as is well known in the art.

Cooling for the nose section is provided as shown in the Eberhardt patent, in both the integrally cast or separable embodiments.

An important feature of the preferred embodiments of the baffle nose tuyere of this invention is gas flow efficiency. The baffle plate extends into the main bore toward the butt wall of the tuyere at the same angle the slot depends therefrom, resulting in diversion of gases with minimum intra tuyere eddying. While the angle B, shown in FIG. 4, is not critical, it should be less than 90 in order to prevent burning of the furance wall, and, an angle B as shallow as about would reduce the available cross sectional area in which to provide a coolant passageway in the nose, thus reducing the efficiency of the cooling system. For blast furance tuyeres, an angle A of about 60 is preferable.

The design of the deflecting means may vary depending on the securing means. A baffle plate with no anchoring into the slot, but which is silver soldered, or cast, only on the inner wall of the main bore is within the scope of this invention. Likewise, a baffle plate extending upward into the main bore from the inner wall of the slot also falls within my inventive concept.

Many other variations are within the scope of my invention. The length and diameter of the tuyere may be changed. The slot may be changed in width, length and location around the circumference of the nose. The size and height of the deflecting means may vary.

Each of the preferred embodiments of the tuyere of this invention, detachable or integrally cast, has distinctive advantages. A detachable deflecting means is readily adaptable to existing tuyeres, and may be replaceable. An integrally cast deflecting means, on the other hand, enables the annular cooling chamber to be enlarged into the deflecting means as shown in FIG. 4.

The outstanding advantage of the baffle nose tuyere of this invention is the universal nature of the deflecting means. Before this invention, control of the volume of gases being diverted to burn under the tuyere could only be controlled by the size of the slot or notch opening. The deflecting means of this invention by varying the baffle plate height, permits a precise combination of volume and velocity of gases needed to achieve maximum agitation in the exact area under the tuyere where buildup is maximum.

I claim:

1. In a tuyere or like furance part having an outer wall, an inner wall, a nose wall joining said outer and inner wall at the discharge end of the tuyere, a butt wall joning said outer and inner wall at the other end of the tuyere, said inner wall defining a main bore for the flow of gases therethrough from the butt to the nose wall of the tuyere, the improvement comprising:

a. a slot extending downwardly toward said discharge end from said main bore through said inner wall and said outer wall and b. deflecting means located on said inner wall between said slot and said nose wall and extending into said main bore.

2. The tuyere of claim 1 in which said deflecting means is detachable.

3. The tuyere of claim 1 in which said deflecting means extends from said inner wall toward said butt wall at an angle of about 60 with said inner wall.

4. The tuyere of claim 3 in which said slot depends from said main bore at the same angle said deflecting means extends from said inner wall so that said deflecting means forms a continuous extension of said slot.

5. In a tuyere or like furance part having a body section and a detachable nose section, each of said sections including an outer wall and an inner wall, said inner wall defining a main bore for the flow of gases therethrough from the body section to the nose section, the improvement comprising:

a. a slot extending downwardly from said main bore through said inner wall and said outer wall of said nose section, and

b. deflecting means located on said inner wall adjacent said slot and extending into said main bore to cause a portion of said gases to flow through said auxiliary bore.

6. The tuyere of claim 5 in which said deflecting means is detachable.

7. The tuyere of claim 5 in which said deflecting means extends from said inner wall toward said butt wall at angle of about60 with said inner wall.

8. The tuyere of claim 7 in which said slot depends from said main bore at the same angle said deflecting means extends from said inner wall so that said deflecting means forms a continuous extension of said slot.

Claims

1. In a tuyere or like furance part having an outer wall, an inner wall, a nose wall joining said outer and inner wall at the discharge end of the tuyere, a butt wall joning said outer and inner wall at the other end of the tuyere, said inner wall defining a main bore for the flow of gases therethrough from the butt to the nose wall of the tuyere, the improvement comprising: a. a slot extending downwardly toward said discharge end from said main bore through said inner wall and said outer wall and b. deflecting means located on said inner wall between said slot and said nose wall and extending into said main bore.

2. The tuyere of claim 1 in which said deflecting means is detachable.

3. The tuyere of claim 1 in which said deflecting means extends from said inner wall toward said butt wall at an angle of about 60* with said inner wall.

5. In a tuyere or like furance part having a body section and a detachable nose section, each of said sections including an outer wall and an inner wall, said inner wall defining a main bore for the flow of gases therethrough from the body section to the nose section, the improvement comprising: a. a slot extending downwardly from said main bore through said inner wall and said outer wall of said nose section, and b. deflecting means located on said inner wall adjacent said slot and extending into said main bore to cause a portion of said gases to flow through said auxiliary bore.

6. The tuyere of claim 5 in which said deflecting means is deTachable.

7. The tuyere of claim 5 in which said deflecting means extends from said inner wall toward said butt wall at angle of about 60* with said inner wall.