US3662447A

US3662447A - Method for producing a nozzle-load for a water cooled blowing lance

Info

Publication number: US3662447A
Application number: US61090A
Authority: US
Inventors: Otto Schweng; Hellmuth Smejkal; Hans Vereb; Karl Eicher
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG; Voest AG
Priority date: 1969-08-14
Filing date: 1970-08-05
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16
Also published as: ES187281Y; DE2058159A1; LU61505A1; ES382405A1; CA948404A; DE2058159B2; FI50341C; ES187281U; AT318673B; BE754652A; FR2056865A5; ZA705327B; SE382468B; DE2034575B2; DE2058159C3; JPS5036405B1; DE7026215U; DE2034575C3; DE2034575A1; FI50341B

Abstract

The disclosure relates to a nozzle-head for a water-cooled blowing lance comprising at least one outlet opening for a gaseous refining agent and, if desired, fine-grained fluxes, an inlet piece, at least one nozzle tube leading through a watercooled space and a front plate to which the at least one nozzle tube is connected, in which the improvement resides in that both the inlet piece and the front plate are provided with tubular projections which are connected with each other to form said nozzle tubes, the connection plane lying perpendicularly to the nozzle-head axis at a distance from the front plate amounting to about one-fourth to two-thirds of the height of the nozzle-head. The number of connecting seams corresponds to the number of nozzle tubes; the seams are far away from the front plate and thus sheltered from any danger to damage.

Description

United States Patent [151 3,662,447 Schweng et al. 1 May 16, 1972 [54] METHOD FOR PRODUCING A NOZZLE- 2,397,084 3/1946 Bernhardt ..29/48l LOAD FOR A WATER COOLED 3,228,612 H1966 Graham et al. BLOWING LANCE 3,477,112 11/1969 Yerkins ..29/l57 C [72] Inventors: Otto Schweng; Hellmuth Smejkal; Hans p E h R C b ll Vere); Karl of Ausma Assistant Examiner-Donald C. Reiley, 111 [73] Assignee: Vereinigte Osterreichische Eisenund A'mmeyKun Kelman Stahlwerke Aktiengesellscaft, Linz, Austria [57] ABSTRACT 22 Filed: Aug. 5, 1970 I The disclosure relates to a nozzle-head for a water-cooled PP N03 61,090 blowing lance comprising at least one outlet opening for a gaseous refining agent and, if desired, fine-grained fluxes, an 30 Foreign Application p Data inlet piece, at least one nozzle tube leading through a watercooled space and a front plate to which the at least one nozzle Aug. 14, 1969 Austria ..A 7830/69 tube is connected in which the improvement resides in bat both the inlet piece and the front plate are provided with tubu- [52] g 2 29/501 lar projections which are connected with each other to form I t 3 53 6 ig said nozzle tubes, the connection plane lying perpendicularly d /29/157C 2 to the nozzle-head axis at a distance from the front plate 0 am zglblc 239/132 amounting to about one-fourth to two-thirds of the height of the nozzle-head. The number of connecting seams cor- 56 responds to the number of nozzle tubes; the seams are far 1 References Cited away from the front plate and thus sheltered from any danger UNITED STATES PATENTS to damage- 2,378,516 6/1945 Timmerman et al ..29/l57 C 7 Claims, 8 Drawing Figures 9 10 I I l a,

i: I 17 I8 "E i611 PATENTEDHAY 16 I972 SHEET 1 BF 2 FIG-7.2a (33 FIG. la

FIG. 2b

INVENTORS 0W0 SQHVIENC-a HeLLMuJH 5MIKAL Hans vea BY KHRL E\L R AGENT METHOD FOR PRODUCING A NOZZLE-LOAD FOR A WATER COOLED BLOWING LANCE The invention relates to a nozzle-head for a water-cooled blowing lance comprising one or several outlet openings for a gaseous refining agent and, if desired, fine-grained admixtures, an inlet piece, one or several nozzle tubes leading through a water-cooled space and connected with a front plate, and to a method for producing such nozzle-head.

In basic oxygen steelmaking methods the oxygen necessary for refining the pig iron is blown onto the metal bath by means of water-cooled blowing lances. These blowing lances are provided at their lower end with nozzle-heads usually made of oxygen-free electrolyte copper which guarantees a long life of the nozzle-head because of the good heat conductivity and the poor affinity of copper to oxygen.

In the course of the development of basic oxygen methods at first blowing lances with only a single outlet for oxygen and, if desired, fine-grained fluxes were used. As a rule, the blowing lances comprised an oxygen supply tube and a nozzle-head, the outlet opening in the nozzle-head being preferably designed to be converging-diverging (Laval-nozzle). The nozzle-heads were produced from preforged blanks by chip removal. Later on, nozzle-heads with several outlets, so-called multi-hole nozzles, were used for larger converters; in this type of nozzles the holes are arranged in a manner that their axes are inclined to the blowing lance axis under a specific angle and the refining agent leaves these holes in several streams so that the reaction area of the oxygen with the melt is enlarged. Today, for most basic oxygen converters multi-hole nozzles are used which have e.g. three, four, five or six outlet openings. At first the noule-heads for such blowing lances were manufactured exactly as those for the one-hole nozzles. It was found, however, that this manufacturing process was unsuitable because the medium part of the nozzle-head, the so-called star, is greatly worn as a result of insufficient cooling, which may lead to a leakage and an unfavorable blowing performance which again causes slopping of slag and metal from the converter and a higher nitrogen content of the steel. It was realized that the nozzle-heads, which so far had been made of one piece, had to be divided into several individual parts; these parts are produced separately and then connected with each other by soldering or welding soas to permit access of the cooling water to the individual nozzle tubes. The individual parts are primarily produced by forging so that a finegranular structure is present in the material; cast parts have a coarse and porous structure and are unsuitable for this application. In the method employed so far e.g. for the production of a three-hole nozzle, an inlet piece and a front plate are separately manufactured by drop forging whereupon these parts are worked by means of chip removal and connected with each other via three interposed prefabricated nozzletubes by soldering or welding. This way of manufacturing necessitates exact working and fitting of the individual parts, soldering or welding is very time consuming, and great manual dexterity is needed because it is difficult to connect the nozzle tubes, which are arranged very closely side by side, with the front plate and the inlet piece. The life of the multi-hole nozzles thus produced was improved but still it may happen that the nozzle-heads are ruined prematurely owing to unavoidable faults in the manufacturing process. A particular disadvantage resides in that two partition planes are present in that part of the nozzle-head which gets into contact with oxygen; of these planes one lies very closely to the surface of the front plate. In case of flame erosion of the nozzle-head in the vicinity of the outlet openings it may happen that the soldering seam of this partition plane gets undone which would result in a failure of the nozzle-head.

The invention is aimed at creating a new nozzle-head for oxygen blowing lances with one or sever 1 outlet openings with which these disadvantages and provided are avoided. Furthermore the invention is aimed at a method for producing such nozzle-head in a simple, safe and cheap way guaranteeing an improved, prolonged life.

' the nozzle-head.

Preferably a water deflecting body is resting on ribs of the front plate, said body being provided with recesses whose number and shape corresponds to the number and shape of the nozzle tubes, the walls of said recesses surrounding the nozzle tubes for at least two-thirds of their circumference thus forming continuous annular cooling-water canals.

The method according to the invention for the production of a nozzle-head is characterized by the steps of: producing blanks for the inlet piece and the front plate each with studs in a number corresponding to the number of the nozzle tubes; providing for planar surfaces at the end of the studs of either blank perpendicularly to the nozzle-head axis e.g. by milling, grinding, turning or the like; drilling equidistant holes parallel to the nozzle-head axis through the studs of either blank in the area of the outlet opening to be made at a later point; if desired, arranging a prefabricated annular water deflecting body on the blank for the inlet piece; combining the blanks provided with the holes and inserting preferably annular soldering foils between the areas of contact of the stud ends of either blank; heating the blanks to soldering temperature and cooling them subsequently; mechanically working the blanks which are now soldered together, i.e. boring or drilling the outlet openings, working on the bevel edges for the weld connection with the tubes of the blowing lance, milling a groove at the inlet piece and a supporting surface on the ribs of the front plate; and, if desired, connecting the finished nozzle-head comprising the inlet piece and the front plate with a blowing lance.

Suitably, the combined two blanks are put onto an auxiliary means comprising a plate and guiding pins vertically arranged thereto, said guiding pins engaging into the holes of the blanks thus affording centering and fixing of these parts.

Preferably the two blanks for the inlet piece and the front plate and, if desired, the water deflection body are produced by drop forging from pressed material which was preforged in one or several heats, particularly copper, so that a high degree of shaping is achieved, which amounts to about 5 to 25 fold, preferably 10 to 15 fold, shaping for the blank for the front plate.

The annular water deflection body may be composed of two parts.

In order that the invention may be more fully understood these and further features of the invention shall now be explained by reference to the accompanying drawings.

FIG. 1 a is a vertical sectional view of a nozzle-head connected with a blowing lance according to the known construction and manufacturing technique, which was also employed by applicants so far.

FIG. 1 b is a horizontal sectional view along line I--] of FIG. 1 a.

FIG. 2 a is a vertical sectional view of the nozzle-head according to the invention and FIG. 2 b is a horizontal sectional view along line IIII of FIG. 2 a.

FIGS. 3 a, 3 b and 3 0 illustrate the method according to the invention and show vertical sectional views of the blanks for the inlet piece and the front plate, respectively, and of the water deflecting body.

FIG. 4 is a vertical sectional view through the blanks for the inlet piece and the front plate which are combined with the help of an auxiliary device according to a specific embodiment of the method according to the invention.

The nozzle tip which belongs to the art and is shown in FIG. 1 a comprises a nozzle-head 1 which gets into contact with the refining agent, and comprises a water deflecting ring 2 forming a separate constructional part which guides the cooling water to the nozzle-head l. The nozzle-head 1 comprises an inlet piece 3, three individual nozzle tubes 4 and the front plate 5 which parts are rigidly connected with each other by soldering or welding. The axes of the nozzle tubes 4 are inclined towards the vertical line. In the water deflecting ring 2 recesses 6 are provided; annular canals are formed between the walls of these recesses and the nozzle tubes 4 through which canals cooling water flows with high speed in the direction shown by the arrows in FIG. 1 a, i.e. in downward direction toward the front plate 5. The

individual parts

3, 4, 5 of the nozzle-head l are connected with each other at six junctures (there are three junctures at 7 and three at 8); the three junctures 7 lie in planes close to the surface of the front plate 5 and therefore they are in great danger when the nozzle-head is used in a converter. As may be seen from FIG. 1 a it is extremely difficult to solder or weld the conical nozzle tubes 4 which have to be very closely spaced to the front plate 5 and the inlet piece 3 so as to have a leak-proof connection all around. The nozzle-head 1 is welded or soldered via its inlet piece 3 to the oxygen tube 9 of the blowing lance and via its front plate 5 with the jacket tube 11. Between the tubes 9 and 11 a water guiding tube is built in which is rigidly connected with the water deflecting ring 2 which is supported on ribs of the front plate 5 so that the front plate is intensively cooled, too. Particularly endangered zones of the front plate 5 are the middle part (star) denoted with numeral 12 and the edges 13 in the area of the outlet openings 14 for the oxygen.

FIG. 2 a shows for ready comparison the nozzle-head according to the invention. The nozzle-head 1' comprises only two parts, i.e. the inlet piece 3' with tubular projections 17 and a front plate 5 with tubular projections 16; thus, only three junctures 18 are present which are at a great distance from the surface of the front plate 5' and are lying in one plane, which is perpendicular to the axis 33 of the nozzlehead. This connection cannot come undone owing to the influence of heat because the connecting areas are in about the middle of the nozzle-head 1'. It is suitable to arrange the planes of the junctures 18 at a distance from the surface of the front plate 5' amounting to from one-fourth to one-third of the height of the nozzle-head 1'. The ring 2' around which the water circulates is provided with recesses 6 surrounding the tubes 16 through about two-thirds of their circumference, thus forming continuous annular canals; in FIG. 2a the current of the water is illustrated by arrows. The speed with which the water circulates through the nozzle-head is continuously increased in the area of the ring 2 to reach a maximum when the water enters the space defined by the tubes l0, 11. The baffle ring 2' rests on narrow ribs 15' (FIG. 21:). Preferably the ring 2' consists of one piece. In the area of the inlet piece 3' a groove or notch 20 is provided for engaging adjusting screws 19 for centering the water guiding tube 10 relative to the oxygen tube 9.

FIG. 3 a shows a blank 21 for the inlet piece 3' which blank is drop forged from a preformed block in one or two heats. The blank 21 is provided with three conical studs 22 whose outer shape corresponds to the tubularprojections 17. FIG. 30

shows a blank 25 for the front plate 5, which blank 25 is formed in the die from a block which is preformed in one or two heats; in this process a 5 to 25 fold total shaping is to take place; a preferably 10 to 15 fold shaping is necessary in order to obtain a fine-granular and dense structure. The

blanks

21, 25 are preferably made of oxygen-free electrolyte copper. In principle, it is, however, possible to use also other metals, e.g. pure nickel or stainless steel for producing them. The blanks 21 25 have an outer shape which makes it possible to form the

necessary bevel edges

24, 24 and the groove 20 for connecting the nozzle-head with the blowing lance and for engagement of the adjustment screws 19, respectively, at a later point. In FIGS. 3 a and 3 c the inner contours of the tubular projections l6, 17 is shown in dotted lines. After forging, at the ends of the

studs

22, 26, planar surfaces 28, 28' are produced which are perpendicular to the axis 33 of the nozzlehead, and central holes 23, 23' are driven in, so that bores '29 (FIG. 4) may be produced going through the

studs

22, 26. In FIG. 3 b the water deflecting ring 2', which is preferably made of steel in one piece, is shown. This ring 2' lies on the supporting surfaces 27 (FIG. 3 c) of the ribs 15' of the front plate 5' when the nozzle-head is joined to the blowing lance.

FIG. 4 shows an auxiliary device for joining the

blanks

21, 25 which device comprises a plate 30 and vertically arranged guiding pins 32. Previously, holes 29 had been bored into the blanks through the

studs

22, 26 within the predetermined, inner contour of the tubular projections l7, 16, which is shown in dotted lines. The guiding pins 32 engage in these holes 29 and represent a centering means for the

blanks

25, 21. Between the partition planes 28, 28' a solder in the form of an annular solder foil is inserted, whereupon heating to soldering temperature of about 700 to 900 C in a temperature controlled furnace takes place. Then the blanks are cooled slowly to obtain a firm soldering connection between the

blanks

21, 25. If, as shown in FIG. 4, a water circulating ring 2' is used made of one piece, it is inserted after the blank 21 is put onto the auxiliary device comprising the plate 30 and the guiding pins 32 whereupon the blank 25 is joined with the blank 21. After the

blanks

21, 25 are soldered, the auxiliary means is removed and mechanical working is started, i.e. the milling or boring, respectively, of the insides of the tubular projections l6, 17, the bevel edges 24, 24, the groove 20 and the support planes 27 (FIG. 3 a or 3 c, respectively). The finished nozzlehead 1' together with the water circulating ring may then be welded with the

tubes

9, 10, ll of the blowing lance; adjusting screws 19 help to carry out centering of the tube 10.

What we claim is:

1. In a method for producing a nozzle-head for a blowing lance, comprising at least one outlet opening for a gaseous refining agent, an inlet piece, at least one nozzle tube leading through a water-cooled space, and a front plate to which said at least one nozzle tube is connected, the steps of a. producing blanks for the inlet piece and the front plate each with studs in a number corresponding to the number of nozzle tubes;

b. providing for planar surfaces at the ends of the studs of either blank perpendicularly to the nozzle-head axis;

c. drilling equidistant holes parallel to the nozzle-head axis through the studs of either blank in the area of the outlet openings to be made at a later point;

d. uniting the blanks provided with the holes and inserting soldering foils between the areas of contact of the stud ends of either blank;

. heating the blanks to soldering temperature and cooling them subsequently;

f. mechanically working the blanks soldered together, in-

cluding operations of drilling the outlet openings and forming bevel edges for the connection with the blowing lance.

2. The method set forth in claim 1, wherein said blank for said front plate is formed with ribs, a prefabricated annular water deflecting body designed to rest on said ribs is arranged on the blank for the inlet piece before the blanks are combined, and said ribs are machined to provide for a support surface for said annular body.

3. The method set forth in claim 1, wherein the finished nozzle-head comprising the inlet piece and the front plate is connected with a blowing lance.

4. The method set forth in claim 1, wherein a peripheral groove is milled in the inlet piece for engagement therewith of adjusting screws serving as centering means when said nozzlehead is connected with a blowing lance.

5. The method set forth in claim 1, wherein the combined two blanks are put onto an auxiliary means comprising a plate and guiding pins vertically projecting therefrom, said guiding pins engaging the holes of the blanks thus affording centering and fixing of said blanks.

6. The method set forth in claim 1, wherein the two blanks for the supply piece and the front plate are produced by drop forging from pressed metal which was pre-forged in at least one heat so that a high degree of shaping is achieved, namely an about 5 to 25 fold shaping of the blank for the front plate.

7. The method set forth in claim 1, wherein the water deflection body is also made by drop forging. 5

Claims

1. In a method for producing a nozzle-head for a blowing lance, comprising at least one outlet opening for a gaseous refining agent, an inlet piece, at least one nozzle tube leading through a water-cooled space, and a front plate to which said at least one nozzle tube is connected, the steps of a. producing blanks for the inlet piece and the front plate each with studs in a number corresponding to the number of nozzle tubes; b. providing for planar surfaces at the ends of the studs of either blank perpendicularly to the nozzle-head axis; c. drilling equidistant holes parallel to the nozzle-head axis through the studs of either blank in the area of the outlet openings to be made at a later point; d. uniting the blanks provided with the holes and inserting soldering foils between the areas of contact of the stud ends of either blank; e. heating the blanks to soldering temperature and cooling them subsequently; f. mechanically working the blanks soldered together, including operations of drilling the outlet openings and forming bevel edges for the connection with the blowing lance.

4. The method set forth in claim 1, wherein a peripheral groove is milled in the inlet piece for engagement therewith of adjusting screws serving as centering means when said nozzle-head is connected with a blowing lance.

7. The method set forth in claim 1, wherein the water deflection body is also made by drop forging.