Oxygen lance nozzle for converter oxygen supply smelting and oxygen supply method

Abstract

The present invention discloses an oxygen lance nozzle and oxygen supply method for converter oxygen supply smelting, which belongs to the field of iron and steel metallurgy, and solves the problems of splashing, back drying and process control in the converter smelting process after increasing the oxygen supply intensity in the prior art. The oxygen lance nozzle includes a nozzle and a main blowing hole and a secondary blowing hole opened on the nozzle. The main blowing hole and the secondary blowing hole have different apertures, design pressures and Mach numbers at the throat. In the method, when the converter smelting is in the silicon oxygen oxidation stage, the carbon oxygen reaction phase I, the carbon oxygen reaction phase II and the carbon oxygen reaction phase III, the main blowing hole is in a normal working state and the secondary blowing hole is in an abnormal working state; when the converter smelting is in the carbon pulling phase, the main blowing hole is in an abnormal working state and the secondary blowing hole is in a normal working state. The present invention can be used for converter oxygen supply smelting.

Description

Technical Field

[0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to an oxygen lance nozzle and an oxygen supply method for converter oxygen supply smelting. Background Art

[0002] At present, the long process represented by blast furnace-converter is still the world's dominant steel production process. The use of oxygen has greatly improved the production efficiency of the converter. The structure and performance of the oxygen lance used for oxygen supply largely determine the effect of oxygen steelmaking, especially for the top-blown oxygen converter steelmaking process. Among them, the structure of the oxygen lance nozzle determines important process factors such as the contact area between the oxygen jet and the molten pool, the penetration depth of the oxygen jet, the stirring state of the molten pool, the oxidation degree of the elements, the heating rate of the molten pool, and the iron oxide content in the slag.

[0003] In order to ensure that the final phosphorus content of converter-smelted steel meets the standard, a low-intensity oxygen flow rate is generally used. The more common oxygen supply intensity is 3.0-3.5Nm 3 / min / t, long oxygen blowing time, slow production rhythm and large-scale production of low-phosphorus steel varieties have, to a certain extent, restricted the increase in steelmaking output.

[0004] In the prior art, the methods for increasing the oxygen supply intensity of the converter cannot effectively solve the problems of splashing, back drying and process control in the converter smelting process after increasing the oxygen supply intensity. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide an oxygen lance nozzle and oxygen supply method for converter oxygen smelting, which solves the problems of splashing, back drying and process control in the converter smelting process after increasing the oxygen supply intensity in the prior art.

[0006] The present invention provides an oxygen lance nozzle for converter oxygen smelting, comprising a nozzle and a main blowing hole and a secondary blowing hole opened on the nozzle, the aperture of the main blowing hole is different from the aperture of the secondary blowing hole, the design pressure of the main blowing hole is different from the design pressure of the secondary blowing hole, and the Mach number of the throat of the main blowing hole is different from the Mach number of the throat of the secondary blowing hole.

[0007] Further, the total number of the main blowing holes and the auxiliary blowing holes is N=4 to 10;

[0008] The number of main blowing holes is N1=2~5, and the number of auxiliary blowing holes is N2=2~5.

[0009] Further, the number of the main blowing holes is 2, the number of the auxiliary blowing holes is 2, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on the same ring;

[0010] Alternatively, the number of the main blowing holes is 3, the number of the auxiliary blowing holes is 3, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on the same ring.

[0011] Further, the number of the main blowing holes is 3, the number of the auxiliary blowing holes is 3, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on different rings;

[0012] Alternatively, the number of the main blowing holes is 4, the number of the auxiliary blowing holes is 4, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on different rings;

[0013] Alternatively, the number of the main blowing holes is 5, the number of the auxiliary blowing holes is 5, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on different rings.

[0014] Furthermore, the radius of the ring where the main blowing hole is located is r1, and the radius of the ring where the auxiliary blowing hole is located is r2, r1-r2=0~2D1; D1 is the throat diameter of the main blowing hole, m.

[0015] Furthermore, the radius of the main blowing hole R1 = A1 / A 1o =1.17~2.64, A1 is the outlet area of ​​each main blowing hole, m 2 , A 1o is the throat area of ​​each main injection hole, m 2 ;

[0016] The radius of the secondary injection hole R2 = A2 / A 2o =1~1.69, A2 is the outlet area of ​​each auxiliary blowing hole, m 2 , A 2o is the throat area of ​​each secondary injection hole, m 2 .

[0017] Furthermore, the angle α1 between the axis of the nozzle and the axis of the main blowing hole is 10-20°;

[0018] The included angle α2 between the axis of the nozzle and the axis of the auxiliary blowing hole is 10-20°.

[0019] Furthermore, (N1×A 1o ) / (N2×A 2o )=0.5~1;

[0020] N1 is the number of main blowing holes, A 1o is the throat area of ​​each main injection hole, m 2 , the number of N2 main injection holes, A 2o is the throat area of ​​each secondary injection hole, m 2 .

[0021] Furthermore, the Mach number of the throat of the main injection hole is 1.80-2.20, and the Mach number of the throat of the auxiliary injection hole is 1.10-1.55.

[0022] The present invention also provides an oxygen supply method for converter oxygen smelting, using the above oxygen lance nozzle, the converter oxygen smelting is divided into a silicon oxygen oxidation stage, a carbon oxygen reaction stage I, a carbon oxygen reaction stage II, a carbon oxygen reaction stage III and a carbon pulling stage in chronological order, and the oxygen supply method comprises the following steps:

[0023] Step 1: The converter smelting is in the silicon-oxygen oxidation stage, the oxygen supply percentage is β, 0<β≤40%, the oxygen supply pressure is Pg, 1.0P1<Pg≤1.2P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0024] Step 2: The converter smelting is in the first stage of carbon-oxygen reaction, the oxygen supply percentage is β, 40<β≤60%, the oxygen supply pressure is Pg, 0.9P1<Pg≤1.0P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0025] Step 3: The converter smelting is in the second stage of carbon-oxygen reaction, the oxygen supply percentage is β, 60<β≤80%, the oxygen supply pressure is Pg, 0.8P1<Pg≤0.9P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0026] Step 4: The converter smelting is in the third stage of carbon-oxygen reaction, the oxygen supply percentage is β, 80<β≤90%, the oxygen supply pressure is Pg, 0.7P1<Pg≤0.8P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0027] Step 5: The converter smelting is in the carbon pulling period, the oxygen supply percentage is β, 90<β≤100%, the oxygen supply pressure is Pg, Pg=P2, the main blowing hole is in an abnormal working state, and the auxiliary blowing hole is in a normal working state;

[0028] In the oxygen supply method, P1 is the design pressure of the main injection hole, P1 is 0.58~1.1MPa, and P2 is the design pressure of the auxiliary injection hole, P2 is 0.22~0.4MPa.

[0029] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0030] A) The main blowing hole and the auxiliary blowing hole provided by the present invention have different parameters (for example, aperture, set working pressure and Mach number). According to different stages of smelting, the main blowing hole or the auxiliary blowing hole is controlled to be at the designed working pressure through variable pressure operation, so that the main blowing hole or the auxiliary blowing hole is in a normal working state, thereby changing the jet and flow rate, thereby more effectively optimizing the smelting effect.

[0031] B) The oxygen supply method for converter oxygen smelting provided by the present invention can change the jet flow according to the smelting needs of different stages of converter smelting by switching different oxygen lance oxygen supply pressures during the oxygen blowing smelting process, and increase the oxygen supply flow rate while reducing oxygen blowing splashing, thereby realizing converter oxygen supply.

[0032] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0034] Figure 1 This is a schematic diagram of the first structure of an oxygen lance nozzle for converter oxygen supply smelting provided in Example 1 of the present invention, the number of main injection holes = the number of auxiliary injection holes = 2, located in the same ring;

[0035] Figure 2 A schematic diagram of a second structure of an oxygen lance nozzle for converter oxygen supply smelting provided in the first embodiment of the present invention, wherein the number of main injection holes = the number of auxiliary injection holes = 3, which are located in the same ring;

[0036] Figure 3 A third structural schematic diagram of an oxygen lance nozzle for converter oxygen supply smelting provided in the first embodiment of the present invention, wherein the number of main injection holes = the number of auxiliary injection holes = 3, which are located in different rings;

[0037] Figure 4 A fourth structural schematic diagram of an oxygen lance nozzle for converter oxygen supply smelting provided in the first embodiment of the present invention, wherein the number of main injection holes = the number of auxiliary injection holes = 4, which are located in different rings;

[0038] Figure 5 A fifth structural schematic diagram of an oxygen lance nozzle for converter oxygen supply smelting provided in the first embodiment of the present invention, wherein the number of main injection holes is 4, the number of auxiliary injection holes is 5, and they are located in different rings;

[0039] Figure 6A sixth structural schematic diagram of an oxygen lance nozzle for converter oxygen supply smelting provided in the first embodiment of the present invention, wherein the number of main injection holes is 5, the number of auxiliary injection holes is 4, and they are located in different rings;

[0040] Figure 7 This is a seventh structural schematic diagram of an oxygen lance nozzle for converter oxygen supply smelting provided in Example 1 of the present invention, wherein the number of main injection holes = the number of auxiliary injection holes = 5, which are located in different rings.

[0041] Reference numerals:

[0042] 1- Main blowing hole; 2- Auxiliary blowing hole. DETAILED DESCRIPTION

[0043] Preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used to explain the principles of the present invention together with the embodiments of the present invention.

[0044] Embodiment 1

[0045] This embodiment provides an oxygen lance nozzle for converter oxygen supply smelting, see Figures 1 to 7 The oxygen lance nozzle includes a nozzle and a main injection hole 1 and an auxiliary injection hole 2 opened on the nozzle. The aperture of the main injection hole 1 is different from the aperture of the auxiliary injection hole 2, the design pressure of the main injection hole 1 is different from the design pressure of the auxiliary injection hole 2, and the Mach number of the throat of the main injection hole 1 is different from the Mach number of the throat of the auxiliary injection hole 2.

[0046] Since the increase of oxygen supply intensity leads to the increase of jet impact energy, which will lead to the deterioration of process control, the jet impact energy must be effectively controlled to achieve true oxygen supply smelting.

[0047] Compared with the prior art, the multiple parameters (for example, aperture, set working pressure and Mach number) of the main blowing hole 1 and the auxiliary blowing hole 2 provided in this embodiment are different. According to the different stages of smelting, the main blowing hole 1 or the auxiliary blowing hole 2 is controlled to be at the designed working pressure through variable pressure operation, so that the main blowing hole 1 or the auxiliary blowing hole 2 is in a normal working state, thereby changing the jet and flow rate, thereby more effectively optimizing the smelting effect.

[0048] From the perspective of layout, the total number of the main blowing holes 1 and the auxiliary blowing holes 2 is N=4-10, the number of the main blowing holes 1 is N1=2-5, and the number of the auxiliary blowing holes 2 is N2=2-5.

[0049] As for the number and layout of the main blowing holes 1 and the auxiliary blowing holes 2, the following types can be adopted by way of example:

[0050] The first one, see Figure 1The number of the main blowing holes 1 is 2, the number of the auxiliary blowing holes 2 is 2, the main blowing holes 1 and the auxiliary blowing holes 2 are arranged alternately, and the centers of the main blowing holes 1 and the auxiliary blowing holes 2 are located on the same ring.

[0051] The second one, see Figure 2 The number of the main blowing holes 1 is 3, the number of the auxiliary blowing holes 2 is 3, the main blowing holes 1 and the auxiliary blowing holes 2 are arranged alternately, and the centers of the main blowing holes 1 and the auxiliary blowing holes 2 are located on the same ring.

[0052] The third one, see Figure 3 The number of main blowing holes 1 is 3, the number of auxiliary blowing holes 2 is 3, the main blowing holes 1 and the auxiliary blowing holes 2 are arranged alternately, the centers of the main blowing holes 1 and the auxiliary blowing holes 2 are located on different rings, all the main blowing holes 1 are located on the same ring, and all the auxiliary blowing holes 2 are located on another ring.

[0053] For the fourth type, see Figure 4 The number of main blowing holes 1 is 4, the number of auxiliary blowing holes 2 is 4, the main blowing holes 1 and the auxiliary blowing holes 2 are arranged alternately, the centers of the main blowing holes 1 and the auxiliary blowing holes 2 are located on different rings, all the main blowing holes 1 are located on the same ring, and all the auxiliary blowing holes 2 are located on another ring.

[0054] Fifth, see Figure 5 The number of main blowing holes 1 is 5, the number of auxiliary blowing holes 2 is 4, the main blowing holes 1 are divided into a central main blowing hole arranged at the center of the nozzle and surrounding main blowing holes arranged around the central main blowing hole, the surrounding main blowing holes and the auxiliary blowing holes 2 are alternately arranged, the centers of the surrounding main blowing holes and the auxiliary blowing holes 2 are located on different rings, all the surrounding main blowing holes are located on the same ring, and all the auxiliary blowing holes 2 are located on another ring.

[0055] The sixth type, see Figure 6 The number of main blowing holes 1 is 4, the number of auxiliary blowing holes 2 is 5, the auxiliary blowing holes 2 are divided into central auxiliary blowing holes arranged at the center of the nozzle and surrounding auxiliary blowing holes arranged around the central auxiliary blowing hole, the main blowing holes 1 and the surrounding auxiliary blowing holes are alternately arranged, the centers of the main blowing holes 1 and the surrounding auxiliary blowing holes are located on different rings, all the main blowing holes 1 are located on the same ring, and all the surrounding auxiliary blowing holes are located on another ring.

[0056] The seventh type, see Figure 7 The number of main blowing holes 1 is 5, the number of auxiliary blowing holes 2 is 5, the main blowing holes 1 and the auxiliary blowing holes 2 are arranged alternately, the centers of the main blowing holes 1 and the auxiliary blowing holes 2 are located on different rings, all the main blowing holes 1 are located on the same ring, and all the auxiliary blowing holes 2 are located on another ring.

[0057] It should be noted that the arrangement method in which the centers of the main injection holes 1 and the auxiliary injection holes 2 are located in the same ring, corresponding to the first and second methods, is more convenient for processing the oxygen lance nozzle.

[0058] For the setting method in which the centers of the main blowing hole 1 and the auxiliary blowing hole 2 are located in different rings, corresponding to the third, fourth and seventh methods, dual-channel control can be achieved. By controlling the different pressures of different channels, the main blowing hole 1 and the auxiliary blowing hole 2 can work under normal pressure at the same time. Specifically, the dual-channel control can be adopted as follows: Since the main blowing hole 1 and the auxiliary blowing hole 2 are not on the same ring, another layer of air supply pipe can be added in the air supply pipe, divided into two channel air supply slits.

[0059] Regarding the setting of the center main blowing hole 1 or the center auxiliary blowing hole 2, specifically, if the center main blowing hole 1 or the center auxiliary blowing hole 2 is not set at the center position of the nozzle, the high-speed gas will be ejected, and a negative pressure area will be formed at the center position of the nozzle, changing the shape of the jet, and causing erosion at the center position of the nozzle, reducing the service life of the nozzle. Among them, by adding the center main blowing hole 1, corresponding to the fifth method, the area of ​​the main blowing hole 1 is much larger than the area of ​​the auxiliary blowing hole 2. During the smelting process, the main blowing hole 1 is mainly used for smelting, the gas supply intensity is greater, the jet is stronger, the stirring of the molten pool is more intense, and the mass transfer effect is better. However, this method will cause problems such as drying back; by adding the center auxiliary blowing hole 2, corresponding to the sixth method, the area of ​​the main blowing hole 1 and the area of ​​the auxiliary blowing hole 2 are slightly different, the jet is relatively gentle, and the drying back problem can be effectively avoided.

[0060] In order to further adjust the smelting effect, for example, the radius of the ring where the main blowing hole 1 is located is r1, and the radius of the ring where the auxiliary blowing hole 2 is located is r2, r1-r2=0~2D1, for example, r1-r2=0~1D1, wherein D1 is the throat diameter of the main blowing hole 1, m. It should be noted that when r1-r2=0, it means that the centers of the main blowing hole 1 and the auxiliary blowing hole 2 are on the same ring, and when r1-r2≠0, it means that the centers of the main blowing hole 1 and the auxiliary blowing hole 2 are on different rings.

[0061] In order to further adjust the overall layout of the main blowing hole 1 and the auxiliary blowing hole 2 and improve the smelting effect, the radius of the main blowing hole 1 is R1 = A1 / A 1o =1.17~2.64, the included angle between the axis of the nozzle and the axis of the main blowing hole 1 is α1=10~20°, where A1 is the outlet area of ​​each main blowing hole 1, m 2 , A 1o The throat area of ​​each main blowing hole 1, m 2 , the radius of the secondary injection hole 2 R2 = A2 / A 2o=1~1.69, the included angle between the axis of the nozzle and the axis of the auxiliary blowing hole 2 is α2=10~20°, where A2 is the outlet area of ​​each auxiliary blowing hole 2, m 2 , A 2o is the throat area of ​​each auxiliary blowing hole 2, m 2 .

[0062] In order to ensure variable pressure operation at different smelting stages, the area of ​​the main blowing hole 1 and the area of ​​the auxiliary blowing hole 2 are adjusted. It is also necessary to further adjust the total area of ​​the throats of the multiple main blowing holes 1 and the total area of ​​the throats of the multiple auxiliary blowing holes 2. For example, (N1×A 1o ) / (N2×A 2o )=0.5~1, where N1 is the number of main blowing holes 1, A 1o The throat area of ​​each main blowing hole 1, m 2 , the number of N2 main injection holes 1, A 2o is the throat area of ​​each auxiliary blowing hole 2, m 2 In this way, the total area of ​​the main injection hole 1 and the total area of ​​the auxiliary injection hole 2 can be further limited by the above formula, so as to ensure the variable pressure operation in different smelting stages, so that the main injection hole 1 and the auxiliary injection hole 2 work at the designed pressure, thereby changing the jet and flow rate, and optimizing the smelting effect.

[0063] The Mach numbers of the throat of the main injection hole 1 and the throat of the auxiliary injection hole 2 are different. Specifically, the Mach number of the throat of the main injection hole 1 is 1.80-2.20, and the Mach number of the throat of the auxiliary injection hole 2 is 1.10-1.55. In this way, different Mach numbers can meet the needs of different smelting periods and achieve normal work in different smelting periods.

[0064] Embodiment 2

[0065] This embodiment provides an oxygen supply method for converter oxygen smelting, using the oxygen lance nozzle provided in the first embodiment, wherein the converter oxygen smelting is divided into a silicon oxygen oxidation stage, a carbon oxygen reaction stage I, a carbon oxygen reaction stage II, a carbon oxygen reaction stage III and a carbon pulling stage in chronological order, and the oxygen supply method comprises the following steps:

[0066] Step 1: The converter smelting is in the silicon-oxygen oxidation stage, the oxygen supply percentage is β, 0<β≤40%, the oxygen supply pressure is Pg, 1.0P1<Pg≤1.2P1, where P1 is the design pressure of the main injection hole, usually 0.58~1.1MPa. It should be noted that at this time, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0067] This is because, generally, the difference between the actual pressure and the design pressure / design value is not easy to exceed 20%. If it exceeds, insufficient expansion or over-expansion is likely to occur, resulting in changes in the flow morphology. At this stage, rapid oxidation of silicon manganese is the main method, and the oxygen supply pressure is controlled at 1.0P1<Pg≤1.2P1, so that the main blowing hole can work within the design pressure range (for example, the upper limit of the design pressure). While ensuring the impact of the flow, the flow rate can be increased. The auxiliary blowing hole expands insufficiently because it exceeds the normal working upper limit of the design pressure. The expansion of the flow after the outlet causes the flow to decay instantly, increasing the flow while reducing the kinetic energy of the flow.

[0068] Step 2: The converter smelting is in the first stage of carbon-oxygen reaction, the oxygen supply percentage is β, 40<β≤60%, the oxygen supply pressure is Pg, 0.9P1<Pg≤1.0P1, where P1 is the design pressure of the main injection hole, usually 0.58~1.1MPa. It should be noted that at this time, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0069] This is because the carbon-oxygen reaction in the molten pool is violent, the molten pool is stirred violently, and the oxygen supply intensity is not easy to be too high. Similarly, the main blowing hole works normally, and the auxiliary blowing hole works abnormally, but the oxygen supply intensity is reduced.

[0070] Step 3: The converter smelting is in the second stage of carbon-oxygen reaction, the oxygen supply percentage is β, 60<β≤80%, the oxygen supply pressure is Pg, 0.8P1<Pg≤0.9P1, where P1 is the design pressure of the main injection hole, usually 0.58~1.1MPa. It should be noted that at this time, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state;

[0071] At this time, the carbon-oxygen reaction is still relatively violent, but it tends to change to a lower direction. It is necessary to maintain high top blowing stirring, but increase the oxygen supply intensity to avoid overoxidation of the molten pool in advance, and still use the main blowing hole to work normally.

[0072] Step 4: The converter smelting is in the third stage of carbon-oxygen reaction, the oxygen supply percentage is β, 80<β≤90%, the oxygen supply pressure is Pg, 0.7P1<Pg≤0.8P1, among which P1 is the design pressure of the main blowing hole, usually 0.58~1.1MPa, which further reduces the oxygen supply intensity. It should be noted that at this time, the main blowing hole is in normal working state, and the auxiliary blowing hole is in abnormal working state.

[0073] Step 5: The converter smelting is in the carbon pulling stage, the oxygen supply percentage is β, 90<β≤100%, the oxygen supply pressure is Pg, Pg=P2, wherein P2 is the design pressure of the auxiliary blowing hole, usually 0.22~0.4MPa. It should be noted that at this time, the main blowing hole is in an abnormal working state, and the auxiliary blowing hole is in a normal working state. At this time, the oxygen supply intensity should be further reduced, and the jet intensity should be reduced. The auxiliary blowing hole should be selected to work normally, and the flow rate should be reduced while reducing the jet intensity on the basis of the previous stage to avoid iron overoxidation.

[0074] For example, the oxygen supply intensity of the above-mentioned converter oxygen supply smelting method ranges from 4.5 to 6.0 Nm 3 / t·min.

[0075] Compared with the prior art, the beneficial effects of the oxygen supply method for converter oxygen smelting provided in this embodiment are basically the same as the beneficial effects of the oxygen lance nozzle for converter oxygen smelting provided in Example 1, and are not elaborated here.

[0076] In addition, by switching different oxygen lance oxygen supply pressures during oxygen blowing smelting, the jet flow can be changed according to the smelting needs of different stages of converter smelting. For oxygen supply, the oxygen flow rate can be increased while reducing oxygen blowing splashing, thereby achieving converter oxygen supply.

[0077] Specifically, oxygen blowing is carried out at the beginning of converter smelting. The purpose of oxygen blowing is to oxidize impurity elements such as carbon, silicon, manganese, phosphorus, etc. in molten iron and refine molten iron into molten steel. Converter oxygen supply smelting is divided into silicon oxygen oxidation stage, carbon oxygen reaction phase I, carbon oxygen reaction phase II, carbon oxygen reaction phase III and carbon pulling phase in chronological order. The smelting tasks in different periods are not the same. In the conventional smelting process, the oxygen pressure is generally unchanged. The height of the oxygen gun, that is, the gun position, is changed. Even if the oxygen pressure of the gas supply is changed, because the oxygen gun nozzle is a Laval structure, according to gas dynamics, it is necessary to work within the set pressure range to meet the needs of the oxygen jet. Therefore, the conventional operation of changing the oxygen pressure destroys the oxygen jet, or it will affect the effect of the jet on the molten pool, and there is no detailed effect due to the small adjustment range. The two specifications of the nozzles (main nozzle and auxiliary nozzle) set in this embodiment have different design pressures. Due to different tasks in different periods, the switching of the main nozzle / auxiliary nozzle can be completed by switching the pressure to meet the smelting needs of different periods.

[0078] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for supplying oxygen to converter smelting, characterized in that: An oxygen lance nozzle is used, the oxygen lance nozzle comprises a nozzle and a main blowing hole and a secondary blowing hole provided on the nozzle, the aperture of the main blowing hole is different from the aperture of the secondary blowing hole, the design pressure of the main blowing hole is different from the design pressure of the secondary blowing hole, and the Mach number of the throat of the main blowing hole is different from the Mach number of the throat of the secondary blowing hole; The converter oxygen supply smelting is divided into a silicon oxygen oxidation stage, a carbon oxygen reaction stage I, a carbon oxygen reaction stage II, a carbon oxygen reaction stage III and a carbon pulling stage in chronological order. The oxygen supply method comprises the following steps: Step 1: The converter smelting is in the silicon-oxygen oxidation stage, the oxygen supply percentage is β, 0<β≤40%, the oxygen supply pressure is Pg, 1.0P1<Pg≤1.2P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state; Step 2: The converter smelting is in the first stage of carbon-oxygen reaction, the oxygen supply percentage is β, 40<β≤60%, the oxygen supply pressure is Pg, 0.9P1<Pg≤1.0P1, the main blowing hole is in a normal working state, and the auxiliary blowing hole is in an abnormal working state; Step 3: The converter smelting is in the second stage of carbon-oxygen reaction, the oxygen supply percentage is β, 60<β≤80%, the oxygen supply pressure is Pg, 0.8P1<Pg≤0.9P1, the main injection hole is in a normal working state, and the auxiliary injection hole is in an abnormal working state; Step 4: The converter smelting is in the third stage of carbon-oxygen reaction, the oxygen supply percentage is β, 80<β≤90%, the oxygen supply pressure is Pg, 0.7P1<Pg≤0.8P1, the main blowing hole is in a normal working state, and the auxiliary blowing hole is in an abnormal working state; Step 5: the converter smelting is in the carbon pulling period, the oxygen supply percentage is β, 90<β≤100%, the oxygen supply pressure is Pg, Pg=P2, the main blowing hole is in an abnormal working state, and the auxiliary blowing hole is in a normal working state; In the oxygen supply method, P1 is the design pressure of the main injection hole, P1 is 0.58~1.1MPa, and P2 is the design pressure of the auxiliary injection hole, P2 is 0.22~0.4MPa.

2. The oxygen supply method for converter oxygen smelting according to claim 1, characterized in that: The total number of the main blowing holes and the auxiliary blowing holes is N=4~10; The number of the main blowing holes is N1=2~5, and the number of the auxiliary blowing holes is N2=2~5.

3. The oxygen supply method for converter oxygen smelting according to claim 2, characterized in that: The number of the main blowing holes is 2, the number of the auxiliary blowing holes is 2, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on the same ring.

4. The oxygen supply method for converter oxygen smelting according to claim 2, characterized in that: The number of the main blowing holes is 3, the number of the auxiliary blowing holes is 3, the main blowing holes and the auxiliary blowing holes are arranged alternately, and the centers of the main blowing holes and the auxiliary blowing holes are located on the same ring.

5. The oxygen supply method for converter oxygen smelting according to claim 1, characterized in that: The radius of the ring where the main blowing hole is located is r1, and the radius of the ring where the auxiliary blowing hole is located is r2, r1-r2=0~2D1; D1 is the diameter of the main injection hole throat, m.

6. The oxygen supply method for converter oxygen smelting according to claim 5, characterized in that: The radius of the main blowing hole is R1=A1 / A 1o =1.17~2.64, A1 is the outlet area of ​​each main blowing hole, m 2 , A 1o is the throat area of ​​each main injection hole, m 2 ; The radius of the secondary blowing hole is R2=A2 / A 2o =1~1.69, A2 is the outlet area of ​​each auxiliary injection hole, m 2 , A 2o is the throat area of ​​each secondary injection hole, m 2 .

7. The oxygen supply method for converter oxygen smelting according to claim 1, characterized in that: The included angle α1 between the axis of the nozzle and the axis of the main blowing hole is 10-20°; The included angle α2 between the axis of the nozzle and the axis of the auxiliary blowing hole is 10-20°.

8. The oxygen supply method for converter oxygen smelting according to claim 1, characterized in that: (N1×A 1o ) / (N2×A 2o )=0.5~1; N1 is the number of main blowing holes, A 1o is the throat area of ​​each main injection hole, m 2 , N2 is the number of auxiliary injection holes, A 2o is the throat area of ​​each secondary injection hole, m 2 .

9. The oxygen supply method for converter oxygen smelting according to claim 1, characterized in that: The Mach number of the throat of the main injection hole is 1.80-2.20, and the Mach number of the throat of the auxiliary injection hole is 1.10-1.55.

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