A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter

Abstract

The present invention relates to the technical field of iron and steel metallurgy, and specifically to a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter, comprising a central fuel pipe, an oxygen supply pipe coaxially arranged with the central fuel pipe, a cooling water inlet pipe, and a cooling water outlet pipe; wherein: it also comprises a water-cooled nozzle head; the water-cooled nozzle head comprises a fuel nozzle assembly, an oxygen nozzle assembly, and a cooling water nozzle assembly; the fuel nozzle assembly is telescopically connected to the central fuel pipe through a first cup-shaped component; the oxygen nozzle assembly is telescopically connected to the oxygen supply pipe through a second cup-shaped component; the cooling water nozzle assembly is respectively connected to the cooling water inlet pipe and the cooling water outlet pipe. The burner can significantly increase the heat capacity of the burner, reduce the heating time of the metal scrap, and improve the efficiency of preheating the metal scrap in the converter; to reduce the manufacturing and maintenance costs of the burner, and extend the service life of the burner.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a multi-nozzle fuel-oxygen burner used for preheating metal waste in a converter. Background Art

[0002] The BOF is a general metallurgical furnace that uses blasted air, pure oxygen, or pure oxygen plus fuel to oxidize impurities in liquid metal and generate the required heat energy. It is a rotating metallurgical furnace, such as a silver smelting converter and a steel smelting converter. The combustion system on the converter provides heat energy for converter smelting and is an important component of the converter. The combustion air of an ordinary burner is air, which contains a large amount of nitrogen (about 79%), so that the combustion flue gas contains a large amount of nitrogen oxides, which causes serious pollution; and the use of air for combustion will generate a large amount of flue gas, and a large amount of heat will be carried away by the flue gas, which cannot be fully utilized, resulting in low thermal efficiency; therefore, in order to solve the above problems, it is necessary to design a burner with oxygen-enriched combustion air.

[0003] It is known that Journal of Higher Education, Ferrous Metallurgy (1988, No. 2, pp. 17-20, Figure 1 , Bagryantsev V.I. et al.) have disclosed an oxygen-fuel nozzle for supplying oxygen and pulverized coal fuel to the furnace during the converter blowing process; the nozzle comprises a central fuel pipe for supplying pulverized coal in a neutral gas flow, a coaxially arranged oxygen supply pipe, a cooling water supply and discharge pipe, a head with a central pulverized coal nozzle and an oxygen nozzle arranged at a certain angle relative to the pulverized coal nozzle. During the converter furnace blowing process, due to the existence of thermal expansion, the external cooling water outlet will be elongated. In order to ensure the normal assembly and use of the nozzle assembly, a gap of 0.1-0.4 mm is required between the pulverized coal nozzle in the head and the central fuel nozzle. As stated in the Journal of Higher Education, Ferrous Metallurgy (1988, Issue 2, Pages 17-20, Figure 2 , Bagryantsev VI et al.) determined that the gap connection between the pulverized coal nozzle and the fuel pipe will cause strong abrasion and wear on the surface of the pulverized coal nozzle; and during use, the gap between the pulverized coal nozzle and the fuel pipe connection area will gradually expand significantly, resulting in a decrease in the resistance of the nozzle head. In addition, during the furnace blowing process, the pulverized coal fuel will splash due to the spraying of pulverized coal fuel through the nozzle, which will increase the possibility of explosion of the nozzle and the gas exhaust pipeline in the converter; and as the coal combustion process proceeds, the pulverized coal particles will penetrate into the space in front of the oxygen nozzle through the expanded gap, causing the nozzle head to be burned, and then causing cooling water to enter the converter.

[0004] The known existing patent, publication number: SU1167209A1, discloses a gas-oxygen nozzle design for heating scrap metal and blowing metal in a converter (BOF), the nozzle comprises coaxially arranged natural gas and oxygen supply pipes, cooling water supply and discharge pipes, and a head provided with a central natural gas and peripheral oxygen nozzle, the central natural gas nozzle is provided with a gap in a metal cup, the metal cup is rigidly connected to the head, and the gap is 1 / 12 to 1 / 6 of the cross-sectional area of ​​the central natural gas nozzle. When oxygen flows out through the gap, it mixes with natural gas at the nozzle outlet, provides combustion air for natural gas combustion and forms a flame, thereby providing heat energy for the scrap metal inside the converter. However, the head of this nozzle is only equipped with a central gas nozzle, and accordingly, only a high-temperature natural gas combustion flame can be formed to heat the scrap metal, and the oxygen and natural gas are not fully mixed at the nozzle outlet, which leads to the problem of increased scrap metal heating time and uneven heating temperature, which not only makes the production efficiency of the oxygen converter process low, but also causes the scrap metal in the nozzle area to melt locally, forming a highly oxidized slag-metal melt, and the discharge of metal and slag cannot be avoided when ensuring the smooth pouring of pig iron into the BOF. Known existing patents, publication number: SU1397496A1, disclose a nozzle for blowing liquid metal in a neutral gas flow. The nozzle includes an oxygen supply channel, a carbon powder channel in the neutral gas flow, a supply and discharge of cooling water, and a head, in which a main oxygen nozzle and a powder nozzle are installed, and an additional oxygen nozzle connecting the oxygen channel to the powder nozzle. The focal point of the output cross-sectional axis of these additional oxygen nozzles is no more than four times the diameter of the powder nozzle from the end face of the head. Similarly, the head of this nozzle is also equipped with only one central powder nozzle.

[0005] A known prior art patent, publication number: US3823929A, discloses a nozzle for supplying oxygen and liquid fuel oil to a converter (BOF), the nozzle comprising a central fuel pipe for supplying fuel oil, and an insulating pipe arranged concentrically therewith, the insulating pipe being provided with a disc-shaped distributor with holes, in which the inlet portion of the fuel pipe nozzle concentric with the insulating pipe is fixed, an oxygen supply pipe, an inlet pipe and an outlet pipe for cooling water, and a cooling head consisting of an upper cover and a lower cover, between which the water distributor and the oxygen nozzle are placed, the cross-sectional inner contour of these nozzles being composed of an inlet conical portion, a central cylindrical portion and an outlet expansion portion, at the inlet conical portion of each oxygen nozzle, the fuel tubular nozzle is fixed by a spacer, forming an annular gap between the inner contour of the oxygen nozzle and the outer surface of the fuel tubular nozzle, and the length of the gap is variable. However, this type of nozzle fixes the fuel tubular nozzle in the inlet contraction channel of the head oxygen nozzle, which will cause uneven mixing of oxygen and fuel at the outlet of the head end, resulting in insufficient fuel combustion and failure to improve the organization of fuel combustion, which in turn leads to low thermal capacity of the nozzle and low efficiency in preheating metal scrap in the converter; in addition, since the fuel distributor is located outside the nozzle head and the inlet of the fuel tubular nozzle is fixed in the hole of the distributor by welding, the outlet of the fuel tubular nozzle is fixed in the inlet contraction channel of the head oxygen nozzle by a spacer and welding, this will not only reduce the service life of the nozzle, but also greatly increase the complexity of maintenance work, especially when replacing worn fuel tubular nozzles and nozzle heads.

[0006] The present invention provides a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter to solve the problems of the prior art of complicated maintenance work, short service life, low heat capacity and low efficiency of preheating metal scrap in a converter. Summary of the invention

[0007] The purpose of the present invention is to provide a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter to solve the problems of the prior art of complicated maintenance work, short service life, low heat capacity and low efficiency of preheating metal scrap in a converter.

[0008] The technical solution of the present invention is: a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter, comprising: a central fuel pipe, an oxygen supply pipe, a cooling water inlet pipe, and a cooling water outlet pipe coaxially arranged with the central fuel pipe; the upper ends of the central fuel pipe, the oxygen supply pipe, the cooling water inlet pipe, and the cooling water outlet pipe are sealed and connected to each other by locking washers and welds respectively; a fuel inlet is welded to the top of the central fuel pipe by a weld; an oxygen inlet, a cooling water inlet, and a cooling water outlet are welded to the oxygen supply pipe, the cooling water inlet pipe, and the cooling water outlet pipe by welds respectively; wherein, a water-cooled nozzle head is also included; the water-cooled nozzle head comprises a fuel nozzle assembly, an oxygen nozzle assembly, and a cooling water nozzle assembly; the fuel nozzle assembly is telescopically connected to the central fuel pipe by a first cup-shaped component; the oxygen nozzle assembly is telescopically connected to the oxygen supply pipe by a second cup-shaped component; the cooling water nozzle assembly is connected to the cooling water inlet pipe and the cooling water outlet pipe respectively.

[0009] Preferably, the fuel nozzle assembly comprises a piston-type fuel sleeve, a fuel distributor and a plurality of fuel nozzle bodies;

[0010] The bottom of the piston type fuel sleeve is fixedly connected to the fuel distributor;

[0011] A plurality of the fuel nozzle bodies are arranged on the fuel distributor at a certain angle;

[0012] One end of the first cup-shaped component is fixedly connected to the central fuel pipe; the other end of the first cup-shaped component is inserted into the upper part of the piston-type fuel sleeve, and the piston-type fuel sleeve moves relatively in the first cup-shaped component; a rubber ring for sealing is also provided on the upper part of the piston-type fuel sleeve to ensure sealing contact between the piston-type fuel sleeve and the first cup-shaped component.

[0013] Preferably, the fuel distributor includes a distributor upper plate and a lower cone fixedly connected to the bottom of the distributor upper plate; a trapezoidal hole is provided on the side wall of the lower cone; a plurality of through holes are provided at predetermined angles on the distributor upper plate for accommodating the fuel nozzle body; the bottom of the piston type fuel sleeve is fixedly connected to the upper part of the distributor upper plate.

[0014] Preferably, a fuel channel is provided inside the fuel nozzle body; the upper inlet part and the middle part of the outer side of the fuel nozzle body are both cylindrical, and the lower outlet part is hexagonal; the middle part is provided with a positioning protrusion; the positioning protrusion and the ribs of the lower outlet part are arranged in a ring corresponding to each other.

[0015] Preferably, there are four fuel nozzle bodies, and the upper inlet portion is provided with threads; four through holes are provided on the distributor upper plate at predetermined angles, and internal threads are provided in the through holes for threadedly connecting the distributor upper plate with the fuel nozzle body.

[0016] Preferably, the oxygen nozzle assembly comprises a piston-type oxygen sleeve, an oxygen nozzle body having the same number as the fuel nozzle body, and an upper cover;

[0017] The oxygen nozzle body is arranged on the lower end surface of the upper cover at the same predetermined angle, and the upper end surface of the upper cover is fixedly connected to the bottom of the piston type oxygen sleeve through a weld;

[0018] One end of the second cup-shaped component is inserted into the upper part of the piston-type oxygen sleeve, and the piston-type oxygen sleeve can move relatively inside the second cup-shaped component; the other end of the second cup-shaped component is fixedly connected to the oxygen supply pipe; a rubber ring is provided on the upper part of the piston-type oxygen sleeve to ensure sealing contact between the piston-type oxygen sleeve and the second cup-shaped component.

[0019] Preferably, the oxygen nozzle body comprises an inlet portion configured as a cone, a central portion configured as a cylinder, and an oxygen outlet portion configured as a trumpet-shaped port.

[0020] Preferably, the cooling water nozzle assembly includes an intermediate cooling water branch and an external cooling water branch; the intermediate cooling water branch is telescopically connected to the cooling water inlet pipe through a third cup-shaped component; and the external cooling water branch is fixedly connected to the cooling water outlet pipe through a weld.

[0021] Preferably, the water-cooling nozzle head also includes a lower cover; the lower cover is fixedly connected to the external cooling water branch pipe through a weld.

[0022] Preferably, a water distributor is provided between the upper cover and the lower cover; the water distributor is connected to the intermediate cooling water branch pipe via a weld.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] (1) The present invention provides a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter. The burner can be provided with a plurality of fuel nozzle bodies at a predetermined angle so that a plurality of fuel jets can be formed at the burner head, and the formed fuel jets are distributed in the turbulent pulsating annular oxygen jet ejected from the oxygen nozzle body, so that the oxygen and the fuel can be fully mixed, so that the fuel can be more fully burned and a high-temperature flame can be formed at the same time; thereby significantly improving the heat capacity of the burner, reducing the heating time of the metal scrap, and improving the efficiency of preheating the metal scrap in the converter; avoiding the occurrence of local melting of the metal scrap due to excessively long heating time of the scrap metal and uneven heating temperature; thereby solving the problems of low heat capacity of the existing burner and low efficiency of preheating the metal scrap in the converter in the prior art.

[0025] (2) The present invention provides a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter. The water-cooled nozzle head of the burner is only subjected to one circular welding during assembly, which is simple to assemble and convenient to disassemble and replace. The fuel nozzle body and the distributor upper plate are connected to each other by threads, which is convenient for later maintenance and replacement. Therefore, the burner provided by the present application can reduce the labor intensity of manufacturing and assembling the water-cooled nozzle head, simplify and speed up the maintenance work of replacing the water-cooled nozzle head and the fuel nozzle body, thereby reducing the manufacturing and maintenance costs of the burner and extending the service life of the burner. This solves the problems of complex maintenance work and short service life of the existing burners in the prior art.

[0026] (3) The present invention provides a multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter. The fuel nozzle assembly and the oxygen nozzle assembly of the burner form an annular sliding seal connection with the first cup-shaped component and the second cup-shaped component respectively. This can solve the problems of deformation of the water-cooled nozzle head due to elongation of the external cooling water outlet due to thermal expansion during the process of preheating metal scrap in the converter, abnormal assembly between the components of the water-cooled nozzle head, and further damage to the burner. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0028] Figure 1 is a cross-sectional view of the multi-nozzle fuel-oxygen burner of the present invention;

[0029] Figure 2 A top view of the fuel distributor of the present invention;

[0030] Figure 3 A sectional view of the fuel distributor of the present invention along the top view AA direction;

[0031] Figure 4A top view of the fuel nozzle body of the present invention;

[0032] Figure 5 A sectional view of the fuel nozzle body of the present invention along the top view BB direction;

[0033] Figure 6 is a cross-sectional view of the multi-nozzle fuel-oxygen burner of the present invention;

[0034] Among them, 1. central fuel pipe; 11. fuel inlet; 2. oxygen supply pipe; 21. oxygen inlet; 3. cooling water inlet pipe; 31. cooling water inlet; 4. cooling water outlet pipe; 41. cooling water outlet; 5. locking washer; 51. weld; 6. lower cover, 61 water distributor; 7. fuel nozzle assembly; 71. piston fuel sleeve; 72. fuel distributor; 73. fuel nozzle body; 74. distributor upper plate; 75. lower cone; 76. trapezoidal hole; 77. through hole; 78. positioning protrusion; 79. thread; 70. fuel channel; 8. oxygen nozzle assembly; 81. piston oxygen sleeve; 82. oxygen nozzle body; 83. upper cover; 9. cooling water nozzle assembly; 91. intermediate cooling water branch; 92. external cooling water branch; 12. first cup-shaped component; 13. second cup-shaped component; 14. third cup-shaped component; 15. rubber ring. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with specific embodiments:

[0036] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "inside", "outside", "side", "upper end face", "lower end face", etc. are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred to components must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0037] A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter comprises a central fuel pipe 1 and an oxygen supply pipe 2, a cooling water inlet pipe 3, and a cooling water outlet pipe 4 coaxially arranged with the central fuel pipe 1; wherein the upper ends of the central fuel pipe 1, the oxygen supply pipe 2, the cooling water inlet pipe 3, and the cooling water outlet pipe 4 are sealed and connected to each other through locking washers 5 and welds 51 respectively; a fuel inlet 11 is welded to the top of the central fuel pipe 1 through the weld 51; an oxygen inlet 21, a cooling water inlet 31, and a cooling water outlet 41 are welded to the side walls of the oxygen supply pipe 2, the cooling water inlet pipe 3, and the cooling water outlet pipe 4 through welds 51 respectively.

[0038] The burner also includes a water-cooled nozzle head; Figure 1As shown, the water-cooled nozzle head includes a fuel nozzle assembly 7, an oxygen nozzle assembly 8, and a cooling water nozzle assembly 9; wherein the fuel nozzle assembly 7 is connected to the central fuel pipe 1 through a first cup-shaped component 12; the oxygen nozzle assembly 8 is connected to the oxygen supply pipe 2 through a second cup-shaped component 13; the cooling water nozzle assembly 9 is respectively connected to the cooling water outlet pipe 4 and to the cooling water inlet pipe 3 through a third cup-shaped component 14.

[0039] The fuel nozzle assembly 7 includes a piston-type fuel sleeve 71, a fuel distributor 72 and four fuel nozzle bodies 73. Figure 2 , Figure 3 As shown, the fuel distributor 72 includes a distributor upper plate 74 and a lower cone 75 fixedly connected to the bottom of the distributor upper plate 74; at the same time, a trapezoidal hole 76 is provided on the side wall of the lower cone 75 for supplying oxygen to the head upper cover 83; four cylindrical through holes 77 are evenly arranged at a certain predetermined angle on the distributor upper plate 74 for accommodating the fuel nozzle body 73; and the inner side of the cylindrical through hole 77 is provided with an internal thread for easy connection with the fuel nozzle body 73. In other embodiments, the distributor upper plate 74 can be provided with a plurality of fuel nozzle bodies 73 evenly arranged at a certain predetermined angle according to actual use requirements, for example, two, six, five or three fuel nozzle bodies 73 are provided. In other embodiments, the through hole 77 provided on the distributor upper plate 74 can be of other shapes, and the shape of the through hole 77 matches the shape of the outer side surface of the upper inlet portion of the fuel nozzle body 73.

[0040] like Figure 4 As shown, the fuel nozzle body 73 is provided with a fuel passage 70 inside, and the fuel passage 70 is cylindrical; the outer side surface of the fuel nozzle body 73 is composed of one or more different shapes; when the outer side surface of the fuel nozzle body 73 has only one shape, the shape of the outer side surface of the fuel nozzle body 73 should match the shape of the through hole 77; when the outer side surface of the fuel nozzle body 73 is composed of multiple different shapes, only the shape of the outer side surface of the upper inlet portion needs to match the shape of the through hole 77. Figure 5 As shown, the outer side of the fuel nozzle body 73, its upper inlet part and the middle part are both cylindrical, and its lower outlet part is hexagonal; and the upper cylindrical inlet part is provided with a thread 79 for threading the fuel nozzle body 73 with the fuel distributor 72; the middle cylindrical part 36 is provided with positioning protrusions 78, and these positioning protrusions 78 are arranged in a ring corresponding to the hexagonal ribs. In this embodiment, the outer side of the fuel nozzle body 73 and the lower outlet part are set to be hexagonal, which is helpful for the installation and removal of the fuel nozzle body 73; when the fuel nozzle body 73 needs to be replaced, the fuel nozzle body 73 can be screwed with a matching hexagonal wrench, and slipping can be prevented during the screwing process.

[0041] One end of the first cup-shaped component 12 is fixedly welded to the bottom of the central fuel pipe 1 through a weld 51; the other end of the first cup-shaped component 12 is inserted into the upper part of the piston-type fuel sleeve 71, and the piston-type fuel sleeve 71 can move relatively inside the first cup-shaped component 12; a rubber ring 15 is also provided on the upper part of the piston-type fuel sleeve 71 to achieve a sealed connection between the piston-type fuel sleeve 71 and the first cup-shaped component 12. The bottom of the piston-type fuel sleeve 71 is fixedly connected to the upper part of the distributor upper plate 74, thereby achieving a telescopic connection between the fuel nozzle assembly 7 and the central fuel pipe 1.

[0042] The oxygen nozzle assembly 8 comprises a piston-type oxygen sleeve 81, an upper cover 83 and four oxygen nozzle bodies 82; the bottom of the piston-type oxygen sleeve 81 is fixedly connected to the upper end surface of the upper cover 83 through a weld 51, and the connection between the peripheral side of the bottom of the piston-type oxygen sleeve 81 and the upper cover 83 is sealed; the oxygen nozzle body 82 is fixedly connected to the lower end surface of the upper cover 83 at the same predetermined angle as the fuel nozzle body 73; the oxygen nozzle body 82 comprises an inlet portion set as a cone, a central portion set as a cylinder, and an outlet portion set as a trumpet-shaped port. The oxygen nozzle assembly 8 is inserted and sleeved on the fuel nozzle assembly 7, so that the oxygen nozzle body 82 is sleeved on the fuel nozzle body 73, so that the positioning protrusion 78 set on the outer surface of the fuel nozzle body 73 is located in the central part of the oxygen nozzle body 82 and abuts against the inner side wall of the central part of the oxygen nozzle body 82; at the same time, the upper end surface of the upper cover 83 and the lower cone 75 are welded together at the position where they contact each other through a weld 51. In this embodiment, the positioning protrusion 78 can not only play a role of limiting, but also serve as a spoiler to change or guide the flow rate and flow of oxygen. In other embodiments, the shape of the oxygen nozzle body 82 can be set according to the shape of the outer side of the fuel nozzle body 73. One end of the second cup-shaped component 13 is fixedly welded to the bottom of the oxygen supply pipe 2 through a weld 51; the other end of the second cup-shaped component 13 is inserted into the upper part of the piston-type oxygen sleeve 81, and the piston-type oxygen sleeve 81 can move up and down inside the second cup-shaped component 13; a rubber ring 15 is also provided on the upper part of the piston-type oxygen sleeve 81 to achieve a sealed contact between the piston-type oxygen sleeve 81 and the second cup-shaped component 13, thereby achieving the mutual connection between the oxygen nozzle assembly 8 and the oxygen supply pipe 2.

[0043] The cooling water nozzle assembly 9 includes an intermediate cooling water branch pipe 91 and an external cooling water branch pipe 92; a boss is provided on the top of the intermediate cooling water branch pipe 91, and a groove is provided on one end of the third cup-shaped component 14 at a position corresponding to the boss on the top of the intermediate cooling water branch pipe 91. When the intermediate cooling water branch pipe 91 is connected to one end of the third cup-shaped component 14, the boss is located in the groove, and a small gap exists between the top of the boss and the bottom of the groove, so that the intermediate cooling water branch pipe 91 and the third cup-shaped component 14 can be retractably connected; the other end of the third cup-shaped component 14 is connected to the cooling water inlet pipe 3 through a weld 51. The external cooling water branch pipe 92 and the cooling water outlet pipe 4 are fixedly welded together through a weld 51.

[0044] The water-cooled nozzle head also includes a lower cover 6, which is sealed and connected to the external cooling water branch pipe 92 via a weld 51. A water distributor 61 is also provided between the upper cover 83 and the lower cover 6, and the water distributor 61 is connected to the intermediate cooling water branch pipe 91 via a weld 51.

[0045] The working principle of the multi-nozzle fuel-oxygen burner is as follows: cooling water enters the cooling water inlet pipe 3 through the cooling water inlet 31, and then flows into the water distributor 61 between the upper cover 83 and the lower cover 6 through the annular gaps between the oxygen supply pipe 2 and the cooling water inlet pipe 3, between the second cup-shaped component 13 and the third cup-shaped component 14, and between the piston-type oxygen sleeve 81 and the intermediate cooling water branch pipe 91. Then, the cooling water is guided to the central part of the lower cover 6 through the turning channel between the upper cover 83 and the water distributor 61 and between the oxygen nozzle body 82; thereafter, the cooling water flows into the annular gaps between the intermediate cooling water branch pipe 91 and the external cooling water branch pipe 92 and between the cooling water inlet pipe 3 and the cooling water outlet 4 through the water outlet channel between the water distributor 61, the lower cover 6 and the oxygen nozzle body 82, and is finally discharged through the cooling water outlet 41.

[0046] Oxygen is delivered to the oxygen supply pipe 2 through the oxygen inlet 21, and then enters the upper cover 83 of the head through the annular gaps between the central fuel pipe 1 and the oxygen supply pipe 2, between the second cup-shaped component 13 and the first cup-shaped component 12, between the piston-type fuel sleeve 71 and the piston-type oxygen sleeve 81, and the trapezoidal hole 76 on the side wall of the lower cone 75; then the oxygen flow is distributed to the four oxygen nozzle bodies 82, and then passes through three variable-length annular gaps and then sprays out. The three variable-length annular gaps are: the annular gap between the inner surface of the conical inlet part of the oxygen nozzle body 82 and the outer side surface of the upper inlet part of the fuel nozzle body 73, the annular gap between the inner surface of the cylindrical central part of the oxygen nozzle body 82 and the outer side surface of the middle part of the fuel nozzle body 73 with six positioning protrusions 78, and the annular gap between the inner surface of the outlet part of the oxygen nozzle body 82 set as a trumpet end and the outer side surface of the lower hexagonal outlet part of the fuel nozzle body 73. Since a positioning protrusion 78 is provided in the middle portion of the fuel nozzle body 73, and the positioning protrusion 78 abuts against the inner side wall of the central portion of the oxygen nozzle body 82, and the lower outlet portion of the fuel nozzle body 73 is hexagonal, the positioning protrusion 78 and the hexagonal ribs can serve as spoilers in the gap to provide power for the turbulent pulsation of oxygen; therefore, a turbulent annular pulsating oxygen jet is formed at the outlet of the oxygen nozzle body 82, thereby increasing the intensity of the mixing of oxygen and fuel.

[0047] Coal powder fuel, natural gas or liquid fuel oil in the form of nitrogen injection is transported to the central fuel pipe 1 through the fuel inlet 11, and then enters the fuel distributor 72 for distribution through the central fuel pipe 1, the first cup-shaped component 12 sealedly connected to the central fuel pipe 1, and the piston-type fuel sleeve 71 connected to the first cup-shaped component 12; the fuel distributor 72 distributes the fuel into four parts and then transports it to the fuel nozzle body 73 connected to it, and sprays it through the fuel channel 70 inside the fuel nozzle body 73, forming four fuel jets on the hexagonal end face of the fuel nozzle body 73.

[0048] By supplying fuel and oxygen simultaneously through the fuel nozzle body 73 and the oxygen nozzle body 82, it can be ensured that at the outlet of the burner, a fuel jet is formed to be distributed in the turbulent pulsating annular oxygen jet formed, and four high-temperature flames are formed to point to the surface of the metal scrap in the converter. Compared with the conventional tube-in-tube nozzle, the burner provided in this embodiment, the fuel jet flowing out of the fuel nozzle body 73 having the fuel channel 70 is distributed in the turbulent pulsating annular oxygen jet ejected from the oxygen nozzle body 82, which can fully mix the oxygen and the fuel, so that the fuel burns more fully and forms a high-temperature flame at the same time; thereby, the heat capacity of the burner can be significantly improved, the heating time of the metal scrap can be reduced, and the dispersion characteristics of the interaction between the high-temperature flame and the metal scrap surface can be provided; at the same time, the phenomenon of partial melting of the metal scrap before the hot metal is poured into the converter can be avoided, thereby achieving the purpose of saving pig iron and improving the production efficiency of the converter process.

[0049] Since an annular sliding sealing connection is formed between the second cup-shaped component 13 and the piston oxygen sleeve 81, and between the first cup-shaped component 12 and the piston fuel sleeve 71 through the rubber ring 15, during the process of preheating metal scrap in the converter, the linear elongation of the burner head oxygen nozzle body 82 and the fuel nozzle body 73 caused by the elongation of the external cooling water outlet due to thermal expansion can be compensated.

[0050] In addition, when assembling the water-cooled nozzle head of the burner head, only one annular welding is required, that is, the annular connection between the external cooling water branch pipe 92 and the cooling water outlet pipe 4; therefore, when disassembling and replacing the water-cooled nozzle head, it is only necessary to cut off the external cooling water branch pipe 92, and then respectively disassemble the connection between the piston oxygen sleeve 81 with the rubber ring 15 and the second cup-shaped component 13, between the piston fuel sleeve 71 and the first cup-shaped component 12, and between the intermediate water pipe 30 and the third cup-shaped component 14. In addition, if the fuel channel 70 in the center of the fuel nozzle body 73 is worn, worn out, etc. and needs to be replaced, the old fuel nozzle body 73 can be directly unscrewed from the distributor upper plate 74 of the water-cooled nozzle head, and a new fuel nozzle body 73 can be screwed on using a hexagonal wrench that matches the hexagonal shape of the outer side of the fuel nozzle body 73 for replacement; in this way, it is not necessary to cut off the water-cooled nozzle head from the upper central fuel pipe 1 and the oxygen supply pipe 2 and then weld a new head. This maintenance and replacement method without removing the fuel nozzle body 73 from the suspended working position can significantly reduce the difficulty of maintenance, and can also save time and material costs. Therefore, the burner provided in this embodiment can simplify and speed up the maintenance work of replacing the water-cooled nozzle head and the fuel nozzle body 73 by reducing the labor intensity of manufacturing and assembling the water-cooled nozzle head, thereby reducing the manufacturing and maintenance costs of the burner and extending the service life of the burner.

[0051] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter, comprising: A central fuel pipe (1), an oxygen supply pipe (2) coaxially arranged with the central fuel pipe (1), a cooling water inlet pipe (3), and a cooling water outlet pipe (4); The upper ends of the central fuel pipe (1), the oxygen supply pipe (2), the cooling water inlet pipe (3) and the cooling water outlet pipe (4) are sealed and connected to each other via locking washers (5) and welds (51); a fuel inlet (11) is welded to the top of the central fuel pipe (1) via a weld (51); an oxygen inlet (21), a cooling water inlet (31) and a cooling water outlet (41) are welded to the oxygen supply pipe (2), the cooling water inlet pipe (3) and the cooling water outlet pipe (4) via welds (51); It is characterized by: it also includes a water-cooling nozzle head; The water-cooling nozzle head comprises a fuel nozzle assembly (7), an oxygen nozzle assembly (8), and a cooling water nozzle assembly (9); The fuel nozzle assembly (7) is telescopically connected to the central fuel pipe (1) via a first cup-shaped component (12); the oxygen nozzle assembly (8) is telescopically connected to the oxygen supply pipe (2) via a second cup-shaped component (13); the cooling water nozzle assembly (9) is respectively connected to the cooling water inlet pipe (3) and the cooling water outlet pipe (4); The fuel nozzle assembly (7) comprises a piston-type fuel sleeve (71), a fuel distributor (72) and a plurality of fuel nozzle bodies (73); The bottom of the piston-type fuel sleeve (71) is fixedly connected to the fuel distributor (72); A plurality of the fuel nozzle bodies (73) are arranged on the fuel distributor (72) at a predetermined angle; A fuel passage (70) is provided inside the fuel nozzle body (73); The upper inlet portion and the middle portion of the outer side surface of the fuel nozzle body (73) are both cylindrical, and the lower outlet portion is hexagonal; The middle portion is provided with a positioning protrusion (78); the positioning protrusion (78) is arranged in a ring shape corresponding to the ribs of the lower outlet portion.

2. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 1, characterized in that: One end of the first cup-shaped component (12) is fixedly connected to the central fuel pipe (1); the other end of the first cup-shaped component (12) is inserted into the upper part of the piston-type fuel sleeve (71), and the piston-type fuel sleeve (71) moves relatively in the first cup-shaped component (12); A rubber ring (15) for sealing is also provided on the upper part of the piston type fuel sleeve (71), so that the piston type fuel sleeve (71) and the first cup-shaped component (12) are in sealed contact.

3. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 2, characterized in that: The fuel distributor (72) comprises a distributor upper plate (74), and a lower cone (75) fixedly connected to the bottom of the distributor upper plate (74); a trapezoidal hole (76) is provided on the side wall of the lower cone (75); a plurality of through holes (77) are provided on the distributor upper plate (74) at predetermined angles for accommodating the fuel nozzle body (73); The bottom of the piston-type fuel sleeve (71) is fixedly connected to the upper part of the distributor upper plate (74).

4. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 3, characterized in that: There are four fuel nozzle bodies (73), and the upper inlet portion is provided with a thread (79); four through holes (77) are provided on the distributor upper plate (74) at a predetermined angle, and internal threads are provided in the through holes (77) for threadedly connecting the distributor upper plate (74) and the fuel nozzle body (73).

5. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 2, characterized in that: The oxygen nozzle assembly (8) comprises a piston-type oxygen sleeve (81), oxygen nozzle bodies (82) having the same number as the fuel nozzle bodies (73), and an upper cover (83); The oxygen nozzle body (82) is arranged on the lower end surface of the upper cover (83) at the same predetermined angle, and the upper end surface of the upper cover (83) is fixedly connected to the bottom of the piston type oxygen sleeve (81) through a weld (51); One end of the second cup-shaped component (13) is inserted into the upper part of the piston-type oxygen sleeve (81), and the piston-type oxygen sleeve (81) can move relatively inside the second cup-shaped component (13); the other end of the second cup-shaped component (13) is fixedly connected to the oxygen supply pipe (2); and a rubber ring (15) is provided on the upper part of the piston-type oxygen sleeve (81) to ensure sealing contact between the piston-type oxygen sleeve (81) and the second cup-shaped component (13).

6. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 5, characterized in that: The oxygen nozzle body (82) comprises an inlet portion configured as a cone, a central portion configured as a cylinder, and an oxygen outlet portion configured as a trumpet-shaped port.

7. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 6, characterized in that: The cooling water nozzle assembly (9) comprises an intermediate cooling water branch pipe (91) and an external cooling water branch pipe (92); the intermediate cooling water branch pipe (91) is telescopically connected to the cooling water inlet pipe (3) via a third cup-shaped component (14); and the external cooling water branch pipe (92) is fixedly connected to the cooling water outlet pipe (4) via a weld (51).

8. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 7, characterized in that: The water-cooling nozzle head also includes a lower cover (6); The lower cover (6) is fixedly connected to the external cooling water branch pipe (92) via a weld (51).

9. A multi-nozzle fuel-oxygen burner for preheating metal scrap in a converter according to claim 8, characterized in that: A water distributor (61) is provided between the upper cover (83) and the lower cover (6); the water distributor (61) is connected to the intermediate cooling water branch pipe (91) via a weld (51).

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