AU600923B2 - Tuyere for torch guniting of metallurgical plant - Google Patents

Description

n1flUT Director 0 GNEUPORN0 I PR MS LNO T~ GRIFFITH HASSEL FRAZER G.P.O. BOX 4164 SYDNEY, AUSTRALIA All-Al -67765/87, BCEMH4PHA31 OPrAHI43AUWLA' P CT HHTEAJ1JEKTYAbH~fCOBCTBEHH6~ MEKIHAP)4HAZ 3A5IBKA, OrIYBJIMKOBAHHA5I B COOTBTCT91-H C ,TorOBOPOM 0 rIATEHTHOfr KoorIEPAIHI4 (PCT) (51) Mewijiyapoiwajj maccHaja~Wu 11306PeTejmx4 C21C 5/44, F27D 1/16 (11) Homep memKlzyaapomuofi ny6jimicamm: WO 88/02786 Al (43) ,laT2 Me2KzVHaPo0=0fI Hy6AM~auus: 21 anpenq 1988 (21.04.88) (21) Homep me)K yapoa~oiO 3aRBIxH: PCT/SU86/00098 (22) /AaTa meMe, apomzoii 11o2an: 17 oKTsi6psi 1986 (17.10.86) (71) 3aiinRrejn,: BCECo103HbMI roCYTAPCTBEH- HbUH HHCTH4TYT HAYtIHO-1HCCJIE,40OBA- T8J~bCKkX 1H rIPOEKTHbIX PABOT orHEY- IOPHOR flPOMhIIIIJIEHHOCTH4 [SU/SU]; Rle- -HHrpaxi 199034, Ha6. MaKapoBa, g. 2 (SU) [VSE- SOJUZNY GOSUDARSTVEN-NYINSTITUTNAU- CHNO-ISSLEDOVATELSKIKH I PROEKTNYKH RABo r OGNEUPORNOT PROMYSHFLENNOSTI, Leningrad (72) H~o6peTaTej. MqEMEPHC Oner HHAKoj~aeBH%4; To- Hetpc 340119, yni. ll~eTHHHa, zi. 1, KB. 87 (SU) [CHE- MERIS, Oleg Nikolaevich, Donetsk 103E- (DOBCKH14 113paimb A6paMoaHi; JleHHHrpaaI 194036, yni. PoHtiaPHas., *u 21, KB. 3 (SU) [JUZE- FOVSKY, lzrail Abramovich, Leningrad U14- B14H I4ropB IlaBTOBWIl; JieraiirpaAt 199155, yii. Ko- IN, Igor Paviovich, Leningrad ILIEPUIIHEB uja eKcaHflp AnieicaHanPoB~Tl; Reiirpap 192071, U n Eacceiiaq, z. 101, KCB. 453 (SU) ['.".HERSHNEV, 0. lexandrAlexandrovich, Leningrad B;Y'PHM 0 amapa IIeTpoaHa; HOBOKY3HeLIK 654048, KeMepOB- I- Kcaff o6ii., yn. Tope3a, p. 81, KB3.82 (SU) [BUGRIM, o LU amara Petrovna, Novokuznetsk MAJIAXOB IHxaI4J BacisnbeBuM; MOCKBa 117437, yn. Miuuy- L0. o-MaKnaR, z. 22, KCB. 289 (SU) [MALAKCHOV, Miail Vasilievich, Moscow AfI3ATYJIOB a~bmx Ca611poBH,4; HOBOKY3HeLI 654000, KemepoB- CKaAl o6,i., yii. KHpOBa, a. 56, KcB. 46 (SU) [AIZA- TULOV, Rafik Sabirovich, Novokuznetsk YtIHTEJIb JIeB MHxaimoB3H4 HoBoTCy3etac 654000 KemepoBcKaq o6mi, yni. KHpoBa, A. 56, KB. 3 (SU) [UCHITEL, Lev Mikhailovich, Novokuznetsk AneKcefi CepreewaH'; HoBoKy3He~ac 654051, Kehiepoacjcas o6.n., np. Jppy2K6bi, 8, KB. 116 (SU) [NJUNYAEV, Alexei Sergeevich, Novokuznetsk KJIO 1 1HEB Mxisxa.-m MHxafrnoB.14; HOBOKy3Heuic 654040, KemepoazIcasl o6ji., np. COBeTcK014 ApmHH, 43, KB. 115 (SU) [KLOCHNEV, Mikhail Mikhailovich, Novokuznetsk. KP1O- KOB IOp~f BacieBHwt; HoBoKy3HeLuK 654054, KemepoBcKasr o6n., yn. ApXHTeKTOpOB, 4. 22, KB. 193 (SU) [KRJUKOV, Jury Vasilievich, Novokuznetsk MAPAKYJI14H lOpmfi ApicameBHl; HOBO- Ky3HCLIK 654031, KemepoBcKBja oft., rip. COBeTcXOi Apmmi, a. 52, KB. 60 (SU) [MRAKL'LIN, Jury Arkadievich, Novokuznetsk BACAJIAEFI 1 4I-opb HBaHoBwN; HoBoicy3Helic 654048, KemeponcKast o6n., yn. 40 nreTr BJIKCM, a. 98, KCB. 87 (SUJ) [BASALAEV, Igor Ivanovich, Novokuznetsk XAPAXYJIAX BaeffhikI Cepreealsq; )KaaHOB 341026, 4ToHeuKas. o6n., np. rlo6exubi, p. 115, KB. 116 (SU) [KHAEAKHULAKH, Vasily Sergeevich, Zhdanov '1BH4JIEB AiiaTonmfi AHpipeeBHR; )Kaa- HOB 341047, 4ToHeUtias[ o6ni., 6yjmbBap llIeBxieHKo, zi. 274, KB. 95 (SUJ) [CHVILEV, Anatoly Andreevich, Zhdanov KAJJYBA IlaBern AjnexcaHpBH'l; )KaaHOB 341015,, ThHeuKasi ofn., yji. Ap-rema, p. 72, KB. 53 (SU) [KADUBA, Pavel Alexandrovich, Zhdanov (SU)1. ITJI14CKAHOBCKHfI AneKcaHup CTa- H14ciaBoBHq; 4THernponjerpBCK 320027, nep. YpHj-.

Koro, p. 4, KB. 10 (SU) [PLISKANOVSKY, Alexandr Stanislavovich, Dnepropetrovsk CYP)KEHKO BBJneHTHH 4ZmiiTpjieBHR; .)KaaHOB 341041, ,EOHeuicaq oft., 6ynbaap KomcomoinhcKi4A, g. 64, KB. 14 (SU) [Sb RZHENKO, Valentin Dmitrievich, Zhdanov (74) Arer: TOPrOBO-IIPOMLIIIIIEHHA5I IAJIATA CCCP; MOCKCBa 103735, yn. Kyftnbueaa, z. .512. (SU) [THE USSR CHAMBER OF COMMERCE AND INDUSTRY, Moscow (81) Yxa3ammi~e rocygapcTma: AT (eBpone~icKIf1 faTe14T), AU, BR, DE (eBpone~cci naTeHT), FR (eBponeficKJmf naTeHi-), GB (eBponeftccHi naTeHT), HU, IT (eBporief~cKHui naTeHT),, JP, NL (eBpone~Kni niaTeHT), SE (eBponefcKi rnaTeHT) Oiry6jngxonaua C om'iemoMi o me.2wcyHapO6H0M floucKe 00 'j on ri l (A 154) Title: TUYERE FOR TORCH GUNITING OF METALLURGICAL PLANT4 5s4) Ha=Hsme 19.3o6peTeMME: (DVPMA. Jl5 (DAKEJIbHOrO TOPKPETHPOBAH14AI METAJIJPIPI'HtIqECKOrO ArPETATA2 5 7 A tuyere for torch guniting of a metallurgical plant lined with a refractory material comprises a cooled casing inside which pipelines 4) for supplying oxygen and the gunite 11 mass into the cavity of the plant. The tuyere further comprises at least one slot-shaped nozzle, intended for supplying the g unite mass to the lining area to he restored, connected to the pipelin 7C4})fbr supplying the gunite mass and located on the side wall of the tuyere, near its end-face, parallel to the axes of the-pipe- 'lines 2, 3, The tuyere is also provided with nozzles for supplyig the oxygen to the lining ar ,-to be restored which are connected to.

the pipeline for supplying the oxygen and are spa\i enlaogthlnersdsfecI slot-shaped nozzle for supplying the gunite mass.

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-1A- TUYERE FOR FLAME-JET GUNMTING OF A METALLURGICAL UNIT Technical Field The invention relates to repair equipment to be used in the ferrous metallurgy, and more particularly, it deals with a tuyere for flame-jet guniting of a metallurgical unit.

Background of the Invention Now the requirements imposed upon quality of coating applied to the lining of metallurgical units has become more stringent.

Widely known in the art is a tuyere for flame-jet guniting of linings (cf. US patent No. 3883078, 1975), comprising a cooled casing in which are accommodated concentrically extending pipelines for supplying a pulveru- 15 lent mixture of a refractory with fuel and for supplying oxygen to the metallurgical unit, and a nozzle for supp- *lying them to the unit lining disposed in the end wall of the pipelines and extending at right angles with respect thereto.

20 Finely ground periclase powder is used as refractory and fuel is in the form of coke dust. Periclase powder and coke dust are mixed in a ration of 3:1, and this mixture will be hereinafter referred to as guniting composition.

.25 When guniting composition is applied to the lining 0o using a tuyere having one nozzle, particles of guniting composition are entrained with oxygen jet, mixed there- *with and deposited on the lining. Fuel (coke particles) is heated by the lining, ignited and burnt. A high-tempe- 30 rature zone is formed in the vicinity of the lining, and periclase particles getting into this zone are heated to a plastic state so that if contacted with the lining surface, they are welded thereto so as to form a coating strongly bonded to the lining refractories.

Periclase particles mainly from the peripheral zone

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2 of the oxygen jet that have not come in contact with the lining surface in the zone of impingement of the oxygen jet laden with guniting composition upon the lining are lost with gases removed from the impingement zone into a gas scrubbing system or environment.

Efficiency of application of guniting composition in carrying out the flame-jet guniting of a metallurgical unit in using the tuyere of this type is rather low and it does not exceed 50 (the ratio of weight of refractory powder that welds to the lining in a given area to weight of refractory powder supplied to the unit).

Also known in the art is a tuyere for flame-jet guniting (cf. USSR Inventor's Certificate No. 755851 of December 9, 1977, publ. in Off. Bull. No. 30, August 1980), comprising a cooled casing accommodating coaxial pipelines for supplying guniting composition and oxygen into the interior of a metallurgical unit and having at least one slit nozzle for supplying guniting composition to the area of the lining being patched communicating 20 with the pipeline for supplying guniting composition and located on the side wall adjacent to the end side of the tuyere in parallel with the pipeline axis, and nozzles for supplying oxygen to the area of the lining being patched communicating with the pipeline for supplying oxygen and located adjacent to shorter sides of each slit nozzle for supplying guniting composition.

The advantage of this design is in an improved efficiency of application of guniting composition which is *achieved owing to distribution of guniting composition over the lining surface along the longitudinal plane of symmetry of the slit nozzle.

Particles of guniting composition fly out of the 61 nozzle, are entrained with oxygen jets and directed towards the lining in the form of a plane-parallel flow of a mixture of coke and periclase particles and oxygen.

Coke particles are heated by the unit lining, they are ignited and burnt so as to form a high-temperature zone -3 0* S S

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@050 090505 0 in which periclase particles are heated to a plastic state and weld to the lining surface so as to form a coating thereon.

Periclase particles that did not weld to the lining are lost with gases removed from the guniting zone into atmosphere. In view of a large area of the plane-parallel jet of the mixture of guniting composition and oxygen, periclase particles are sucked-in by the jet surface and are again directed towards the lining. The probability of periclase particles being welded to the lining increases with in an increases in the degree of spread of the plane-parallel jet, i~e. with an increase in the surface area of this jet. Using the tuyere of the abovedescribed type, the efficiency of application of guniting composition is as high as 70 However, as the oxygen nozzles are disposed adjacent to the shorter sides of each slit nozzle for supplying guniting composition, the length of the slit depends on conditions that should be created for mixing guniting 20 composition with oxygen. The longer the slit, with a given distance from the nozzles to the lining being patched, the worse are conditions for penetration of oxygen to the center of the slit-shaped jet of guniting composition. Coke particles would be underburnt in this 25 zone thus resulting in deterioration of quality of the deposited coating and shorter life of the coating.

The shorter the slit, the better is mixing of oxygen with guniting composition and the better is quality and longer service life of the coating, but efficiency of application of guniting composition is lower, i.e.

the effect of spread of the plane-parallel jet of guniting composition over the lining surface being patched is lost in view of a decrease in the surface area of the jet of guniting composition and oxygen and a respective reduction of periclase particles entrained by this surface. As 6 vesult, the tuyere of this type exhibits inadequate efficiency of application of guniting composition, and service life of the resultant coating is also inadequate.

Summary of the Invention The invention is based on the problem of providing a tuyere for flame-jet guniting of metallurgical units having such structural arrangement of its nozzles as to improve efficiency of application of guniting composition and prolong service life of coating.

This problem is solved by the provision of a tuyere for flame-jet guniting of metallurgical units, comprising a cooled casing accommodating coaxial pipelines for supplying guniting composition and oxygen into the interior of the unit and having at least one slit nozzle for supplying guniting composition to the linintg area being patched communicating with the pipeline for supplying guniting composition and located on the peripheral wall of the tuyere adjacent to the end thereof in parallel with the pipeline axis, and nozzles for supplying oxygen the lining area being patched communicating with the pipeline for supplying oxygen, wherein according to the invention, nozzles for supplying oxygen are equally spaced along the long sides of each slit nozzle for supplying guniting composition.

The structural arrangement of nozzles in a tuyere 25 for flame-jet guniting according to the invention allows the jet of a mixture of guniting composition and oxygen to be spread maximum possible on the lining area surface without impairing conditions for mixing of guniting composition with oxygen aver all areas of the lining. This contributes to an increase in the surface area of the jet of guniting composition and oxygen and number of periclase particles Welding to the surface of the lining.

At the same time, this allows temperature to be equalized and increased over the whole extent of the zone of application of periclase powder particles to the lining so that the particles are sintered to a comparatively higher 5 density. All these factors result, in the end, in a improved efficiency of application of guniting composition and longer service life of the coating.

The oxygen supply nozzles in the tuyere for flamejet guniting are preferably mounted at an angle of from to 400 with respect to the longituginal plane of symmetry of the slit nozzle for supplying guniting composition.

This makes it possible to improve mixing of oxygen with guniting composition at the initial portion of the jet of the mixture and to ensure complete entrainment of the plane-parallel flow of guniting composition with oxygen jets so as to impart to particles thereof the desired direction of flight towards the metallurgical unit lining area being patched so as to improve efficiency of application of guniting composition and prolong service life of the coating.

If the nozzles for oxygen supply are mounted at an angle of less than 200 with respect to the longitudinal fe 20 plane of symmetry of the nozzle for supplying guniting *composition, guniting composition will be poorly mixed with oxygen and inefficiently entrained with its jets so that uniformity of distribution of guniting composition over the lining is impaired and guniting flame-jet temperature is lowered. As a result, quality of coating will nO be impaired and its service life will become shorter.

If the oxygen supply nozzles are mounted at an angle greater than 400 with respect to the longitudinal axis of symmetry of the nozzle for supplying guniting composition, a counter-current of oxygen is formed which will offer an additional resistance in the path of flow of guniting composition. As a result, conditions are provided for clogging the path of flow of guniting composition. In addition, oxygen can penetrate into interior of the pipeline for supplying giniting composition, and carbon of the guniting composition may be ignited in the pipeline which'is unacceptable from the safety point of view.

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7 V W -6 V be *go god 0 go** 39 0 goo* 0 a It is preferred that the oxygen supply nozzles provided in the tuyere for flame-jet guniting on either long side of the slit nozzle be disposed in a fan-like fashion, with the fan angle being from 15 to 450.

The fan-like spread of oxygen jets, while providing complete entrainment of the plane-parallel jet of guniting composition, allows the degree of spread of a mixture of guniting composition and oxygen to be increased substantially (by several times). In other words, the zone of spread of the flame jet over the lining surface can be increased as compared with the length of the slit nozzle f or supplying guniting composition and with the distance between the oxygen nozzles disposed along long sides of the slit nozzle which depend on conditions for uniform escape of guniting composition along the slit length (the slit length should not exceed a certain size for each type of guniting composition).

Dimensions of the slit nozzle and, first of all, the length of its long sides, are limited by conditions 20 for uniform escape of guniting composition in the crosssection of the slit. If the slit is too broad, flow rate of guniting composition at the end of the tuyere will be much greater than that at the beginning of the nozzle.

If the slit is too long, quite on the contrary, flow rate of guniting composition at the beginning of the nozzle will be greater than that at the end thereof. In such case the slit nozzle may be clogged with guniting composition so that the lining of a unit will be washedoff by oxygen jets, and its service life will be shorter.

30 The flame-jet guniting is carried out using slit nozzles in which the length is several times as small as the necessary length for spreading the flame jet. The fan-like distribution of oxygen jets, while providing for complete entrainment of the plane-parallel jet of guniting composition therewith, makes it possible to substantially increase the amount of spread of the flame jet over the lining as compared with the slit length.

-7- The surface area of the two-phase jets increases, the number of particles of periclase powder entrained with this surface also increases and efficiency of application of guniting composition is respectively improved.

If the fan angle is smaller than 150, the spread of the flame jet over the lining will be inadequate for a substantial improvement of efficiency of application of guniting composition.

If the fan angle is greater than 45°, the longitudinal component of the flame jet velocity directed along the flame jet spread over the lining increases. The loss of particles of refractory powder will increase in this direction to such an extent that an increase in efficiency of application of guniting composition caused by an increase in the angle of fan will cease.

Brief Description of the Drawings Specific embodiments of the invention will now be described with reference to the accompanying drawings, in which: 20 Fig. 1 shows a schematic representation of a tuyere in the zone of arrangement of nozzles according to the invention, in a front elevation view; Fig. 2 shows a cross-sectional view of the same tuyere, the sectional view being taken along line drawn 25 through nozzles for supplying guniting composition and oxygen; Fig. 3 is a sectional view taken along line III-III in Fig. 2; SFig. 4 is a sectional view taken along line IV-IV in Fig. 2; Fig. 5 schematically shows a longitudinal sectional view of a converter with a tuyere mounted in the interior thereof during guniting of the lining.

AtI i T- 8- Best Mode for Carrying Out the Invention A tuyere for flame-jet guniting (Figs 1, 2, 3 and 4) comprises a cooled casing defined by pipelines 1 and 2 accommodating coaxial pipelines 3 and 4 for supplying oxygen and guniting composition, respectively. The guniting composition is in the form of a pulverulent mixture of a refractory with a carbonaceous fuel in a ratio of 3:1. The annular passage defined between the pipelines 1 and 2 is used for supplying cooling water. The annular passage defined between the pipeline 2 and 3 is used for removal of water. The annular passage defined between the pipelines 3 and 4 (Fig. 2) is used for supplying oxygen. The central pipeline 4 is designed for supplying guniting composition in the form of a suspension in a carrier gas (air in this example) with a weight concentration of 100 200 kg/kg (guniting composition-to-air *ratio).

The tuyere has a slit nozzle 5 for supplying guniting composition. In this embodiment the tuyere has a 20 single slit nozzle 5, but it is understood that there may be more such nozzle 5. The number of nozzles depends on the size of the lining area to be patched.

The slit nozzle 5 is mounted in such a manner that its longitudinal plane of symmetry extends along the 25 axis of the tuyere (in this embodiment, the longitudinal plane of symmetry of the slit nozzle 5 extends through the tuyere axis).

Ten round nozzles 6 for oxygen supply are provided S along the long sides of each slit nozzle 5. In other embodiments of the invention the number and configuration of the nozzles 6 for oxygen supply may be different.

The oxygen supply nozzles 6 are mounted in such a manner that their axes extend at an angle equal to with respect to the longitudinal plane of symmetry of the slit nozzle 5. The nozzles 6 are positioned along the axis of the tuyere in such a manner (Fig. 4) that their axes define a fan-like pattern with an angle of -9fan 3 equal to 250.

Fig. 5 shows the tuyere for flame-jet guniting which is placed into the interior of a metallurgical unit (an oxygen converter 7 in this example). The tuyere has two slit nozzles 5. The nozzles 5 and 6 for supplying guniting composition and oxygen, respectively, are aimed at the lining area being patched where a refractory coating 8 is to be formed. Gases moving back from the patching area are removed from the interior of the converter 7 through a throat 9 and are admitted to an existing gas scrubbing system (not shown in the drawing).

The tuyere for flame-jet guniting of a metallurgical unit functions in the following manner.

Before starting guniting, water supply is turned on for cooling the tuyere, and the tuyere for flame-jet guniting is introduced into the interior of the converter 7.

The tuyere is positioned in such a manner that the nozzles 5 and 6 be directed towards the lining area of •the converter 7 being patched. Guniting composition is supplied through the central pipeline 4 and through the slit nozzle 5. Then oxygen is supplied through the annular passage defined between the pipelines 3 and 4 and through the nozzle 6, the flow rate of oxygen being chosen in such a manner as to ensure complete burning of 25 fuel fed with the guniting composition throu~gh the nozzles After ignition of the fuel, refractory material is 0:0 deposited to the lining areas of the converter 7 being patched. The tuyere may be moved along the longitudinal axis of the converter and rotated about the tuyere axis in any appropriate known manner to facilitate deposition of refractory material and also to cover the whole surface of the lining area being patched.

Outflow of guniting composition from the slit nozzle 5 occurs in the form of plane-parallel jets. Outflow of oxygen from the round nozzles 6 occurs in the form of MW concentrical jets which are distributed in the fan-like 10 fashion along the long sides of the slit nozzles 5 and which are directed towards the plane-parallel jets of guniting composition on either side so that each elementary volume of the flow of guniting composition at the outlet of the nozzle 5 is entrained with oxygen jets and is conveyed further towards the surface of the lining in the directions predetermined by the flow of oxygen jets.

With such a pattern of jets, refractory powder and fuel are mixed with oxygen in the immediate vicinity of the nozzles 5 and 6 of the tuyere and move towards the surface of the lining in the form of a dust-and-gas flow diverging in the fan-like fashion. Particles of fuel are ignited by the lining and burn out. A flame jet is formed in the zone adjacent to the lining, and refractory particles are heated to a plastic state in this flame jet and weld to the lining so as to form thereon a refractory coating. The greater the angle of the fan jet, the greater is the spread of the flame jet over the lining, the larger is its surface area, the greater is the .4 20 number of refractory powder entrained with this surface from the atmosphere within the unit, the greater is the number of particles deposited on, and welding to the lining and, respectively, the better is efficiency of application of guniting composition. With an increase in the 25 angle of inclination of oxygen jets, the degree of mixing of guniting composition with oxygen increases. The fuel- -to-oxygen ratio in all areas of the flame jet is maintained close to the stoichiometi ratio so that the flame jet temperature is increased over the whole extent thereof along the lining surface, and density of the coating thus applied increases with prolongation of its service life.

Industrial Applicability The tuyere according to the invention may be used for patching lining in metallurgical units of cylindrical shape such as converters and steel casting ladles. The invention may also be used for gunitin- planar surfaces of lining, in metallurgical units such as~side walls of steel-making, heating and other fur'naces. The invention may be most advantageously u~ied for patching lining of metallurgical units when hot.

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Claims (4)

1. A tuyere for flame-jet guniting of a metallurgical unit lined with a refractory material, comprising a cooled casing accommodating coaxial pipelines and for supplying guniting composition and oxygen into the interior of the unit, and having at least one slit nozzle for supplying guniting composition to the lining area being patched communicating with the pipeline for supplying guniting composition and located on the peripheral wall of the tuyere adjacent to the end thereof in parallel with the axis of the pipelines, and nozzles for oxygen supply to the lining area being patched communicating with the oxygen supply pipeline, wherein the oxygen supply nozzles are equally spaced along Sthe long sides of each slit nozzle for supplying guniting composition.

S2. A tuyere according to claim 1, wherein the oxygen supply nozzles are mounted at an angle of from 200 to 400 with respect to the longitudinal plane of symmetry of the slit nozzle for supplying guniting composition.

3. A tuyere according to claims 1 and 2, wherein the oxygen supply nozzles provided on either long side of the slit nozzle for supplying guniting composition are arranged s. in a fan-like fashion with an angle of fan being from 150 to 450

4. A tuyere for flame-jet guniting of a metallurgical unit lined with a refractory material substantially as herein described with reference to the accompanying drawings. DATED this 9th day of May, 1990 VSESOJUZNY GOSUDARSTVENNY INSTITUT NAUCHNO-ISSLEDOVATELSKIKH I PROEKTNYKH RABOT OGNEUFORNOI PROMYSHLENNOSTI By their Patent Attorneys GRIFFITH HACK CO. 060 0 6 0604s/EM