US2781190A - Tuyere - Google Patents

Description

Feb. 12, 1957 :awr-:1R 2,781,190

TUYERE Filed March 9, 1951 FlELi- [mentar: Hen/VK WS/e,

United States TUYERE Application March 9, 1951, Serial No. 214,719

2 Claims. (Cl. 2156-41) This invention relates to tuyeres and more particularly to water cooled tuyeres for use in blast furnaces. During the operation of a blast furnace the tuyeres discharge their blast of air radially toward the centerV of the furnace and create an individual combustion area immediately beyond the exit end of each tuyere. ln the tuyeres used prior to my invention there was a great deal of turbulence adjacent the exit end of the tuyere which limited the penetration of the air into the furnace. Because of this and other reasons, a conoid core of inactive materials occurs at the center of the hearth and extends upwardly therefrom. it is of course desirable to reduce the size of this core as much as possible.

As the materials in the furnace burden are reduced and melted, they drop to the hearth in the form of iron or slag. These materials in a molten state till the hearth with the slag on top of the iron until the slag line rises to a level slightly below the underside of the tuyeres.

en this level is reached the furnace is cast. Since the air expands radially in a swirling turbulence as it leaves the tuyere, descending coke and iron is driven across the nose of the tuyere causing abrasive and thermal A destruction of the vertical surface thereof. Also the blast of air agitates the slag and creates a vertical, clockwise rotation of the upper strata thereof, thus causing the slag to Contact the underside of the tuyere nose and adhere thereto. This slag with some iron therein attacks the 4- water cooled shell of the tuyere at the lowest part of the vertical face at the exit end and in many cases causes failure of the tuyere.

While the radial blowing mentioned above is that cornmonly used, it has been suggested to use a non-radial circumferential blast and also a downward blast. The circurnferential blast has many of the disadvantages of the radial blast. The designs of the prior downward blast types of tuyeres are such that the turbulent ow of the blast is aggravated. Also in many instances the degree 5- of curvature within the tuyere proper is such that the view of the furnace interior is restricted and in some instances eliminated. ln addition, cinder sometimes builds up in the tuyeres. l have found that the angles of declination suggested are in most instances too great for best results.

l have found that tuyeres acquire an insulating and abrasive resistant cinderlike coating after they have been in use a relatively short time. This incrustation envelops the tuyere shell from the furnace wall to within 6- an inch or two of the vertical surface of the upper nose from whence it recedes circumferentially to within six or eight inches of the furnace wall at the underside of the tuyere. This formation occurs only in an area outside the inuence of the turbulent, abrasive combustion zone and protects the tuyere from failure.

In the tuyeres used prior to my invention there was danger of an explosion occurring when the tuyere failed. Such explosions endanger furnace personnel and equipment.

It is an object of my invention to provide a tuyere which exhausts a blast of air into the furnace with minimum turbulence.

Another object is to provide a tuyere having a minimum amount of its surface within the turbulent abrasive com# bustion zone.

Still another object is to provide such a tuyere having an eicient, self-cleaning coolant system which in combination with the balanced angle ow of the blast prevents molten iron, slag and the like from entering the tuyere.

A further object is to provide a tuyere of long life which also increases the output of the furnace.

A still further object is to provide a tuyere which eliminates or greatly restricts the danger of explosions when failure of the tuyere occurs.

These and other objects will be more apparent after referring to the following specification and attached drawings, in which: s

Figure 1 i-s a longitudinal section of the tuyere as placed in the tuyere cooler of a blast furnace;

Figure 2 is an enlarged longitudinal section of the tuyere;

Figure 3 is a sectional view taken on the line lll-Ill of Figure 2;

Figure 4 is a sectional View taken on the line lV-IV of Figure 2; and

Figure 5 is a perspective View of the tuyere.

Referring more particularly to the drawings, the reference numeral 2 indicates that part of the furnace wall surrounding the tuyere cooler 4 which suppnrts the tuyere 6 of my invention. The tuyere 6 consists of a body 8 made of a copper alloy or other appropriate material and having an uninterrupted air passageway 10 therethrough for the admission of a blast of air to the furnace, this passage being connected at its inlet end with the source of air supply by means of a pipe 12. Surrounding the air passageway 10 is a chamber 14 to which a cooling uid is supplied by means of an inlet pipe 16. The uid after passing through the chamber 14 is discharged frorn the top thereof through an outlet pipe 18. The air passageway 10 is inclined downwardly at an angle 20. The angle 20 is preferably approximately 12 degrees but the tuyere will operate satisfactorily when the angle is between 5 and l5 degrees. The -diameter of the passageway 10 is preferably greater at its entry end than at its outlet in order to gain the advantages of the nozzle elfect produced thereby. To minimize the vulnerable area of the lower tuyere nose and to compensate for the angled blast passage, the height of the vertical section 22 of the nose is reduced to a minimum commensurate with structural and thermal conductivity requirements. This presentsa vertical surface of 50 percent or less of that present in standard tuyeres. In combination with the angle flow of the blast this reduced section oifers a lower tuyere nose of such proportion that the abrasive agitation of the descending materials as well as the rotating motion of the top strata of liquid stag caused by the reduced turbulence of the blast, occurs below and out of contact with the tuyere, thus greatly increasing thelife of the tuyere. In order to obtain proper cooling and at the same time have a minimum vertical surface exposed to the adverse action of the combustion area, the top part of the body 8 is provided with a slightly sloping portion 24 which extends from the rear thereof to a point adjacent its exit or front end and a steep sloping portion 26 extending from the portion 24 to a vertical top face 28. The height of the face 28 is approximately 11/2 times that of the section 22.

o The coolant chamber 14 is divided into a passageway 30 at its lower end which is ,reduced in height and there- Vfore in cross sectional area as it approaches the nose section'22. From the ypassageway 30 the coolant water passes into Vthe main portion of the chamber 14. VA rib 32 VisV located in the center of the upper nose portion in order to reduceY the swirling, agitated, commingling of theopposed waters at the top of the tuyere. The rib 32 also strengthens the tuyere at a critical point. The coolant passes out through the passageway 18. This construction Vof the coolant chamber causes the velocity of the cooling water to increase to a maximum at the lower nose 22 from which area it passes circumferentially upwardlyvdecreasing in velocity as it rises to the wider upper portion of the chamber, The high velocity of the waiter at the lower nose V22 prevents accumulation or' foreign materials on the chamber walls at this vulnerable location, while its rapid ow increases the cooling efliciency. YThe above construction of the tuyere is such that the insulating abrasive resistant coating mentioned above will form along the tuyere roof tothe vertical position 2S with proportionate increases about the balance of the shell.

vWhile one embodiment of my invention has been shown and described it will be apparent that other adaptations and modications may be made without departing from the scope of the following claims.

I claim:

1. In a blast furnace, a substantially Vertical wall for said furnace, a tuyere having its outer end adjacent the wall of the furnace and its inner end extendingl into the furnace, said tuyere comprising a body having an air passage therethrough, said air passage being inclined f uniformly downwardly and inwardly into the furnace from a point adjacent its outer end, Ythe axis of said air passage being arranged at an angle of between 5 and 15 degrees with the horizontal, said body having a vertical wall surrounding the air passage outlet, said body having a top'portion sloping slightly downwardly and inwardly 4 Y, from its outer end and a portion merging withthe top portion andrsloping at a relatively steep angle downwardly to the top of the said wall, a cooling chamber in said body surrounding said passage, and a passageway in the lower part of said cooling chamber leading from its outer end to its inner end and decreasing in cross section from its outer end to its inner end, the inner end of said passageway having an opening into said cooling chamber.

2. ln a blast furnace, a substantially vertical wall for said furnace, a tuyere having its outer end adjacent the wall of the furnace and its inner end extending into the furnace, said tuyere comprising a body having an air passage therethrough, said air passage beingrinclined uniformly downwardly and inwardly into the furnace from. a point adjacent its outer end, the axis of said air passage' being arranged at an anglerof between 5 and 15 degrees with the horizontal, said body having a vertical wall A surrounding the air passage outlet, said body having a top portion sloping slightly downwardly and inwardly from its outer end and a portion merging with the top portion andV sloping at a relatively steep angle downwardly to the top of the said wall, a cooling chamber in said body surrounding said passage, a rib in said chamber extending between the walls thereof at the steeply sloping portion of said body, and a passageway in the lower part of said cooling chamber leading from its outer end to its inner end and decreasing in cross section from its outer end to its inner end, the inner end of said passageway having an opening into said cooling chamber. Y

References Cited in the fle of this patent UNITED STATES PATENTSY 296,225 Schulze-Berge Apr. 1, 1884 318,604r Devereux May 26, 1885 1,205,568 Ross, Jr Nov. 21, 1916 1,354,032 Dovel Sept. 28, 1920 1,994,115 Y Stoecker Mar. 12, 1935V 2,124,437 Steinbacher July 19, 1938 2,501,265 Diaz Mar. 21, 1950

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