US2497000A

US2497000A - Tuyere structure

Info

Publication number: US2497000A
Application number: US15311A
Authority: US
Inventors: Harry O Johnson
Original assignee: American Steel and Wire Company of New Jersey
Current assignee: American Steel and Wire Company of New Jersey
Priority date: 1948-03-17
Filing date: 1948-03-17
Publication date: 1950-02-07
Anticipated expiration: 1967-02-07

Description

2 497,000 F b 7 1950 H. o. JOHNSON e TUYERE STRUCTURE Filed March 17, 1948 FIE-1-1- Z0 Q 760676625 weer 0 JOHN? ivy/W4 1 Patented Feb. 7, 1950 UNITED STATES PATENT OFFICE TUYERE STRUCTURE Application March 17, 1948, Serial No. 15,311

2 Claims. (Cl. 266-41) This invention relates to tuyeres and more particularly to tuyeres used to conduct the preheated air blast into a blast-furnace.

In present day blast-furnace practice, the hot blast is introduced into the furnace through tuyres which are installed in the furnace about its circumference just below the lower bosh-Iine. These tuyres are usually frusto-conical in shape and cast from a copper alloy or other similar material The number of tuyeres used in blastfurnaces operating today ranges from to 22.

The maintenance of tuyres is an important problem in the operation of a blast-furnace and one that seriously affects iron production. The,

fact that tuyeres must necessarily be positioned in the hearth of a furnace immediately above the molten metal and slag causes them to be subjected not only to the heat and abrasion of the blast entering the furnace but also to the intense heat given off by the molten slag and metal in the hearth. Under these conditions, the tuyres Wear rapidly and burn out after being in use only a relatively short time. This necessitates frequent replacements which result in a high coppe waste as Well as a loss in iron production.

Many attempts have been made to solve this troublesome problem, such as reinforcing the tuyre by providing an insert of a material having a high temperature melting point in the bottom of its nose or by constructing the tuyre with an inwardly sloping nose so as to protect its bottom. Although these changes improve the situation somewhat, furnace operators still find it necessary to replace tuyres frequently during a furnace campaign.

A principal object of my invention is to provide a tuyere that will have a prolonged service life and require few replacements during a blastfurnace campaign.

Another object of my invention is to provide a t'uyre that is designed to effectively withstand the deteriorating conditions that it is subject to when in use.

A further object of my invention is to provide a tuyere having surfaces adapted to receive and retain a layer of protective material thereover.

Still another object of my invention is to provide a tuyre covered with a protective refractory coating and provided with means to transfer the heat from said refractory coating to the cooled shell of the tuyere.

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

Figure 1 is a side elevational view of the tuyre of my invention showing its exterior surface;

Figure 2 is a nose end view of Figure 1;

Figure 3 is a longitudinal-sectional view of the tuyre taken on the line III-III of Figure 1;

Figure 4 is a cross-sectional view of the tuyre taken on the line IV-IV of Figure 3,

Figure 5 is a rear end view of thr tuyre; and

Figure 6 is an enlarged detail section of the tuyere nose showing the heat resistant refractory material applied.

Referring more particularly to the drawings, reference numeral 2 indicates a tuyere having the usual hot air passage 4 therethrough which is surrounded by a cooling chamber 6. As shown in Figures 1 and 2, the exterior surface 8 of the tuyre has spaced-apart, longitudinal and transverse ribs l0 projecting therefrom. The inner wall I! of air passage 6, as seen in Figures 3 and 4, likewise has similar longitudinal and transverse ribs l4 projecting therefrom Longitudinal ribs l0 extend around the nose It of the tuyere and are continuous with the longitudinal ribs l4 projecting from the inner wall i2. A projecting rib It; extends circumferentially around the face of the nose I6 approximately midway between the exterior surface 8 and inner wall l2.

The interior and exterior surfaces of the tuyere between the various ribs are covered with a suitable heat resistant refractory material 20, as shown in Figure 6.

One of the purposes of the waffle-type surface thus formed on the exterior of the tuyre, its nose, and on the interior wall of the air passage is to receive and retain the refractory material applied. To facilitate the keying of the refractory coating onto the exterior surfaces, the ribs [0 can be tapered inwardly toward their centerline, as shown. The ribs l0, l4, and I8 also serve to transfer heat from the refractory 20 to the water-cooled shell of the tuyre body. The refractory coating is preferably of a thickness equal to the height of ribs IO, M, and 3.

It will be apparent that the size and design of this wailie-type pattern can vary widely but, in any case, the construction must be such as to offer reinforcement for retaining the refractory material securely to the body of the tuyre and to transfer heat from the refractory to the cooled tuyre shell.

The advantage of applying refractory to the inner surface as well as the outer surface and the nose is to protect the air passage of the tuyere from destruction in case iron or cinder flows back into the tuyre and also to protect the inner wall from the heat of the hot air blast. The former is a common occurrence if the furnace is too cold, too iimey, if there is a bad distribution of the stock or blast, or if, for any reason, the furnace is too full and the blast is reduced or taken off.

The waiile-type pattern of the outer and inner surfaces of the tuyre is cast directly on the surface portions of the tuyere body when the tuyere is made in the foundry.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims:

I claim:

1. In a tuyere having a body portion with an air passage extending therethrough, the improvement consisting of a network of spaced-apart intersecting ribs projecting from the exterior surface of said body portion, refractory material extending between said ribs, a network of spacedapart ribs projecting from the inner wall of said air passage, and refractory material extending between said ribs.

2. In a tuyere having a body portion with an air passage extending therethrough, the improvement consisting of a network of spaced-apart intersecting ribs projecting from the exterior surface of said body portion, a network of spacedapart intersecting ribs projecting from the inner wall of said air passage, said ribs forming individual compartments on the exterior surface of said body portion and on the inner wall of said air passage, and refractory material extending between said ribs to substantially fill said compartments.

HARRY O. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,393,749 Carstens Oct. 18, 1921 1,441,178 Schiegries et al Jan. 2, 1923 1,793,849 Groninger Feb. 24, 1931 1,883,590 Crosby et al Oct. 18, 1932 2,082,280 Fox et a1 June 1, 1937 2,175,291 Heskett Oct. 10, 1939 Certificate of Correction Patent N 0. 2,497,000 February 7, 1950 HARRY 0. JOHNSON It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 22, before the word ribs insert intersecting;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of May, A. D. 1950.

THQMAS F. MURPHY,

Assistant Commissioner of Patents.