Multifunctional combined injection equipment and injection process for converter top lance

Abstract

The application discloses a converter top gun multifunctional combined injection equipment, which comprises a gas main pipeline, a top gun, a first weighing bin for containing a first powder, a second weighing bin for containing a second powder, a fluidized bed connected with the first weighing bin and the second weighing bin, and a first powder injection bin and a second powder injection bin connected with the fluidized bed, wherein the first weighing bin and the second weighing bin are connected with the gas main pipeline, and the first powder injection bin and the second powder injection bin are connected with the top gun; the first powder is a lime powder or a carbon powder, and the second powder is a lime powder or a carbon powder. The top gun multifunctional combined injection equipment can reduce the consumption of lime and steel materials in the converter process, improve the dephosphorization rate and the quality of molten steel, increase the scrap steel ratio and production efficiency, and realize high efficiency and green smelting. The application further discloses a converter top gun multifunctional combined injection process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel converter smelting process, in particular, the present application relates to a multi-functional combined injection equipment of converter top lance and injection process. BACKGROUND

[0002] Converter injection metallurgy has two major technical schools, namely, bottom injection of various media and top injection of various media. The bottom injection powder is represented by K-OBM, KMS, K-BOP, OBM and other processes, which are applied in steel enterprises such as JFE, Nippon Steel in Japan, Gary in the United States, DOFASCO in North America, and Germany, France, etc. The main problem is that the bottom blowing service life is limited, the equipment is complex, and the cooling medium is strictly required.

[0003] In the 1950s, European converters solved the problem of high-phosphorus hot metal smelting by relying on oxygen lance powder injection technology LD-AC (OLP). Japanese Nippon Steel, JFE and other companies introduced and absorbed LD-AC technology, developed their own powder injection technology, and helped to reduce lime consumption and achieve less slag smelting. The powder injection technology applied in Wakayama Steel Plant dephosphorization furnace controls the phosphorus content of semi-steel hot metal within 0.015%, which lays the foundation for the dephosphorization furnace to provide oxygen for the ultra-high strength, low oxidized iron and less slag smelting. The above top powder injection technology is only limited to injecting lime powder to remove P, and does not involve the technology of temperature compensation by injecting carbonaceous powder or natural gas, and the high-efficiency and green smelting technology of injecting CO2 to reduce carbon and dust emission.

[0004] Converter smelting process mainly completes the tasks of decarburization, dephosphorization and temperature rise, etc. The dephosphorization is realized through the slag-steel interface reaction, that is, the slag requires a certain basicity and oxidizing property. At present, the lime addition of converter smelting is mainly added through the silo. Due to the size of lime block and the dynamic conditions of molten pool, it has a certain influence on the slag making in the early and middle stages of converter, so increasing the specific surface area of lime and improving the dynamic conditions of molten pool are the key to realize high-efficiency dephosphorization and high-efficiency metallurgy. At the same time, the heat compensation during the converter smelting is mainly realized by adding silicon and carbonaceous heat generating agent through the silo, and the heat utilization efficiency is low. Even if the "secondary combustion technology" is used, the heat provided is also very limited. And due to the high oxygen supply intensity of the top lance, the oxidation reaction increases the dust emission of the converter.

[0005] The patent with publication number CN112410497A discloses a production method of converter top and bottom composite powder injection for vanadium extraction. Oxygen lance is used for top blowing oxygen supply and injection of iron oxide powder, and iron oxide powder is injected from the bottom of the furnace by using carrier gas during the oxygen blowing process. The bottom of the furnace is switched to bottom blowing nitrogen gas until the next furnace blowing starts. The patent does not involve related equipment, and it involves the process of injecting iron oxide powder for vanadium extraction. The purpose of powder injection is to control the temperature of molten pool and improve the distribution ratio of vanadium between slag and gold.

[0006] The patent document with publication number CN112094980A discloses a converter top and bottom composite powder injection high-efficiency smelting system and method. The system mainly includes a converter, an oxygen lance, a central powder conveying pipeline, a top blowing powder injection tank, a top blowing carrier gas pipeline, an oxygen lance main blowing gas pipeline, a top blowing gas pipeline, a bottom powder injection element, a distributor, a bottom powder injection pipeline, a bottom blowing powder injection tank, a bottom blowing gas pipeline, and a buffer tank. Before the converter smelting starts, the top and bottom composite injection powder injection amount is calculated, and the medium types of the top blowing main blowing gas, the top blowing powder injection carrier gas, and the bottom blowing gas in different smelting periods are set. During the smelting process, the top lime powder is injected into the converter through the central powder conveying pipeline, and the bottom lime powder is injected into the converter through the bottom powder injection element via the bottom powder injection pipeline. The top blowing two powder injection tanks are independent of each other, and it is difficult to achieve powder injection speed adjustment and mixed injection.

[0007] The patent document with publication number CN114752728A discloses an oxygen lance for oxygen blowing and powder injection decarburization and desulfurization. The oxygen lance includes an oxygen lance nozzle and an oxygen lance shell body connected thereto. The oxygen lance nozzle is provided with a contraction nozzle hole in the center on the basis of a traditional converter oxygen lance nozzle. The oxygen lance shell body includes multiple layers of pipeline channels connected to the oxygen lance nozzle at one end and connected to two sets of oxygen supply pipelines and cooling water inlet and outlet pipelines at the other end. The patent does not involve related powder injection equipment. The oxygen lance nozzle injects oxygen mixed with calcium oxide powder into the converter to achieve effective desulfurization. SUMMARY

[0008] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a top lance multifunctional combined injection device, which aims to reduce lime and steel consumption, improve phosphorus removal rate, and improve product quality.

[0009] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a converter top lance multifunctional combined injection device, which includes a gas main pipeline, a top lance, a first weighing bin for containing a first powder, a second weighing bin for containing a second powder, a fluidized bed connected to the first weighing bin and the second weighing bin, and a first powder injection bin and a second powder injection bin connected to the fluidized bed. The first weighing bin and the second weighing bin are connected to the gas main pipeline, and the first powder injection bin and the second powder injection bin are connected to the top lance. The first powder is a lime powder or a carbon powder, and the second powder is a lime powder or a carbon powder.

[0010] The fluidized bed is connected to a first reversing device, and the first reversing device is connected to the first weighing bin and the second weighing bin. The fluidized bed is connected to the first powder injection bin and the second powder injection bin through a first pipeline and a second pipeline, respectively.

[0011] A first gate valve and a first rotary feeder are arranged between the outlet of the first weighing bin and the first reversing device, and a second gate valve and a second rotary feeder are arranged between the outlet of the second weighing bin and the first reversing device.

[0012] The first powder spraying bin and the second powder spraying bin are connected with a second switching device through a third pipeline and a fourth pipeline respectively, the second switching device is connected with the top lance, and the gas main pipeline is connected with the second switching device.

[0013] The top lance comprises a top lance body and a main gas supply pipe, a water inlet pipe, a water return pipe and a spraying hose connected with the top lance body, and the spraying hose is connected with the first powder spraying bin and the second powder spraying bin.

[0014] The top lance body comprises a center pipe, an intermediate pipe, an inner pipe and an outer pipe, the intermediate pipe is sleeved on the center pipe, the inner pipe is sleeved on the intermediate pipe, and the outer pipe is sleeved on the inner pipe, a powder spraying channel is arranged on the center pipe, a main gas supply channel is formed between the center pipe and the intermediate pipe, a cooling water inlet channel is formed between the intermediate pipe and the inner pipe, a cooling water return channel is formed between the inner pipe and the outer pipe, the cooling water return channel is communicated with the water return pipe, the cooling water inlet channel is communicated with the water inlet pipe, the powder spraying channel is communicated with the spraying hose, and the main gas supply channel is communicated with the main gas supply pipe.

[0015] The center pipe, the intermediate pipe, the inner pipe and the outer pipe are coaxial cylindrical barrels, and are made of container or boiler steel.

[0016] The application further provides a multifunctional combined top lance spraying process for a converter, which adopts the multifunctional combined top lance spraying equipment for the converter and comprises the following steps.

[0017] Step one: selection of powder and calculation of powder and natural gas demand;

[0018] Step two: selection and determination of spraying scheme;

[0019] Step three: loading of cold charge and molten iron into the converter, and starting of blowing by the top lance;

[0020] Step four: smelting;

[0021] Step five: tapping.

[0022] The step four comprises:

[0023] Step 4.1: in the early smelting stage, the spraying gas in the main gas supply channel of the top lance is oxygen, mixed gas formed by mixing oxygen and carbon dioxide, oxygen and nitrogen or oxygen and other inert gases, and the carrier gas in the powder spraying channel of the top lance is mixed gas formed by mixing one or more than two of argon, nitrogen and carbon dioxide;

[0024] Step 4.2: In the middle of smelting, the blowing gas of the main gas supply channel of the top lance is oxygen, mixed gas of oxygen and carbon dioxide, oxygen and nitrogen or other inert gas, the carrier gas of the powder injection channel of the top lance is oxygen, argon, nitrogen, carbon dioxide or mixed gas of two or more of them;

[0025] Step 4.3: In the late stage of smelting, the blowing gas of the main gas supply channel of the top lance is oxygen, mixed gas of oxygen and carbon dioxide or other inert gas, the gas medium of the powder injection channel of the top lance is oxygen or mixed gas of oxygen and carbon dioxide, argon.

[0026] In the step two, if the lime powder and carbonaceous powder injection process for thermal compensation is used, the first weighing bin and the second weighing bin can be filled with lime powder and carbonaceous powder respectively, and the powder in the first weighing bin and the second weighing bin is mixed and transported to any one of the first powder injection bin and the second powder injection bin through the fluidized bed for mixing and injection.

[0027] The top lance multifunctional combined injection equipment of the present application can reduce the consumption of lime and steel materials in the converter process, improve the dephosphorization rate and the quality of molten steel, increase the converter scrap ratio, reduce the consumption of steel materials and process energy consumption, realize the "carbon reduction and emission reduction" high-efficiency green steelmaking. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present specification includes the following drawings, and the shown contents are respectively:

[0029] Figure 1 is a structural schematic diagram of the top lance multifunctional combined injection equipment of the present application;

[0030] Figure 2 is a structural schematic diagram of the top lance;

[0031] Figure 3 is a structural schematic diagram of the top lance body;

[0032] The following valves are marked in the diagram: 1. First ball valve; 2. Second ball valve; 3. First weighing bin; 4. Third ball valve; 5. Second weighing bin; 6. Fourth ball valve; 7. Fifth ball valve; 8. Sixth ball valve; 9. Seventh ball valve; 10. Eighth ball valve; 11. First gate valve; 12. First rotary feeder; 13. Second gate valve; 14. Second rotary feeder; 15. First reversing device; 16. First butterfly valve; 17. First powder spraying bin; 18. Ninth ball valve; 19. Tenth ball valve; 20. Eleventh ball valve; 21. Twelfth ball valve; 22. Thirteenth ball valve; 23. Second powder spraying bin; 24. Second butterfly valve; 25. Fluidized bed; 26. Top gun; 27. Main gas pipeline; 28. Second reversing device; 29. ​​Fourteenth ball valve; 30. 31. First pressure detection device; 32. Second pressure detection device; 33. Third pressure detection device; 34. Fourth pressure detection device; 35. Fifth pressure detection device; 36. Fifteenth ball valve; 37. Sixteenth ball valve; 38. Seventeenth ball valve; 39. Eighteenth ball valve; 40. Material conveying pipeline; 41. Nineteenth ball valve; 42. Twentieth ball valve; 43. Protective gas pipeline; 51. Top gun body; 52. Water inlet pipe; 53. Water return pipe; 54. Spray hose; 55. Connecting device; 56. Main air supply pipe; 61. Powder spraying channel; 62. Main air supply channel; 63. Cooling water inlet channel; 64. Cooling water return channel; 65. Central pipe; 66. Intermediate pipe; 67. Inner pipe; 68. Outer pipe. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0034] like Figure 1 As shown, the present invention provides a multi-functional combined injection device for a converter top lance 26, including a gas main line 27, a top lance 26, a first weighing chamber 3 for containing a first powder, a second weighing chamber 5 for containing a second powder, a fluidized bed 25 connected to the first weighing chamber 3 and the second weighing chamber 5, and a first powder injection chamber 17 and a second powder injection chamber 23 connected to the fluidized bed 25. The first weighing chamber 3 and the second weighing chamber 5 are connected to the gas main line 27, and the first powder injection chamber 17 and the second powder injection chamber 23 are connected to the top lance 26. The first powder is a lime powder or a carbonaceous powder, and the second powder is a lime powder or a carbonaceous powder. The lime powder can be lime powder.

[0035] Specifically, such as Figure 1As shown, the top of the first weighing bin 3 is communicated with the gas main pipeline 27 through the second ball valve 2, and the first weighing bin 3 is provided with the first pressure detection device 30 and the eighteenth ball valve 38, and the first weighing bin 3 can be filled and discharged with gas through the switch combination control of the first ball valve 1 and the eighteenth ball valve 38, so as to adjust the pressure of the first weighing bin 3. The top of the second weighing bin 5 is communicated with the gas main pipeline 27 through the third ball valve 4, and the second weighing bin 5 is provided with the second pressure detection device 31 and the seventeenth ball valve 37, and the second weighing bin 5 can be filled and discharged with gas through the switch combination control of the third ball valve 4 and the seventeenth ball valve 37, so as to adjust the pressure of the second weighing bin 5. The bottom of the first weighing bin 3 is communicated with inert gas (nitrogen or argon, etc.), so as to prevent the material from being hardened and keep it in a fluidized state, and the bottom of the first weighing bin 3 is connected with the fourth ball valve 6, which is used for gas cut-off and delivery. The bottom of the second weighing bin 5 is communicated with inert gas (nitrogen or argon, etc.), so as to prevent the material from being hardened and keep it in a fluidized state, and the bottom of the second weighing bin 5 is connected with the first ball valve 1, which is used for gas cut-off and delivery.

[0036] As shown in Figure 1 , the first weighing bin 3 is connected with the delivery pipeline 39, which is used for the input of the first powder in the first weighing bin 3. The second weighing bin 5 is connected with the delivery pipeline 40, which is used for the input of the second powder in the second weighing bin 5. The powders added in the first weighing bin 3 and the second weighing bin 5 can be the same or different.

[0037] As shown in Figure 1 , the first weighing bin 3 and the second weighing bin 5 are provided with a pressure head and a weighing module, and have a weight weighing function, which can give a continuous analog signal of the net weight of the powder input and a powder mixing amount decreasing signal.

[0038] As shown in Figure 1 , the gas main pipeline 27 is provided with the fourteenth ball valve 29 and the fifth pressure detection device 34, the fourteenth ball valve 29 is used for the gas cut-off and delivery control in the gas main pipeline 27, and the fifth pressure detection device 34 is used for the pressure measurement of the gas main pipeline 27. The gas main pipeline 27 can supply nitrogen, argon, CO2, etc. single or mixed medium according to the demand and has an automatic switching function.

[0039] As shown in Figure 1As shown, the fluidized bed 25 is connected with the first reversing device 15, the first reversing device 15 is connected with the first weighing bin 3 and the second weighing bin 5, and the fluidized bed 25 is connected with the first powder injection bin 17 and the second powder injection bin 23 through the first pipeline and the second pipeline respectively. The first weighing bin 3 is provided with the first gate valve 11 and the first rotary feeder 12 between the outlet of the first weighing bin 3 and the first reversing device 15, the first rotary feeder 12 is located between the first gate valve 11 and the first reversing device 15, and the first gate valve 11 is used to close the outlet of the first weighing bin 3 during maintenance. The first rotary feeder 12 is used to deliver the first powder discharged from the first weighing bin 3 to the first reversing device 15 and control the discharging speed. The second weighing bin 5 is provided with the second gate valve 13 and the second rotary feeder 14 between the outlet of the second weighing bin 5 and the first reversing device 15, the second rotary feeder 14 is located between the second gate valve 13 and the first reversing device 15, and the second gate valve 13 is used to close the outlet of the second weighing bin 5 during maintenance. The second rotary feeder 14 is used to deliver the second powder discharged from the second weighing bin 5 to the first reversing device 15 and control the discharging speed.

[0040] As shown in the figure, Figure 1 The first rotary feeder 12 and the second rotary feeder 14 are communicated with the fluidized bed 25 of a shared pneumatic conveying device, and the first weighing bin 3 and the second weighing bin 5 deliver the powders to the fluidized bed 25 through the first rotary feeder 12 and the second rotary feeder 14 respectively and then to the first powder injection bin 17 and the second powder injection bin 23. The fluidized bed 25 can mix and deliver the powders in the first weighing bin 3 and the second weighing bin 5 to any one of the first powder injection bin 17 and the second powder injection bin 23, or can deliver the powders in any one of the first weighing bin 3 and the second weighing bin 5 to the first powder injection bin 17 or the second powder injection bin 23, and the first reversing device 15 is used to control the powder flow direction and determine the filling of the powders to the first powder injection bin 17 or the second powder injection bin 23. The fluidized bed 25 uses low-pressure gas (such as nitrogen or argon) as the carrier gas, and the powders move along the fluidized bed 25 by gravity and enter the first powder injection bin 17 and the second powder injection bin 23.

[0041] As shown in the figure, Figure 1 The top of the first powder injection bin 17 is communicated with the gas main pipeline 27 through the sixth ball valve 8 and the auxiliary pipeline, and the first powder injection bin 17 is provided with the third pressure detection device 32 and the fifteenth ball valve 35, and the first powder injection bin 17 can be filled and discharged with gas and the pressure of the first powder injection bin 17 can be adjusted through the on-off combination control of the sixth ball valve 8 and the fifteenth ball valve 35. The top of the second powder injection bin 23 is communicated with the gas main pipeline 27 through the twelfth ball valve 21 and the auxiliary pipeline, and the first powder injection bin 17 is provided with the fourth pressure detection device 33 and the sixteenth ball valve 36, and the second powder injection bin 23 can be filled and discharged with gas and the pressure of the second powder injection bin 23 can be adjusted through the on-off combination control of the twelfth ball valve 21 and the sixteenth ball valve 36.

[0042] As Figure 1 shown, the bottom of the first powder spraying bin 17 is connected with inert gas (nitrogen or argon, etc.) to keep the material in the bin in a fluidized state and prevent the material from hardening. The bottom of the first powder spraying bin 17 is connected with the seventh ball valve 9, which is used for gas shutoff and delivery. The seventh ball valve 9 is connected with the gas main pipeline 27. The bottom of the second powder spraying bin 23 is connected with inert gas (nitrogen or argon, etc.) to keep the material in the bin in a fluidized state and prevent the material from hardening. The bottom of the second powder spraying bin 23 is connected with the eleventh ball valve 20, which is used for gas shutoff and delivery. The eleventh ball valve 20 is connected with the gas main pipeline 27.

[0043] As Figure 1 shown, the first powder spraying bin 17 and the second powder spraying bin 23 are respectively connected with the second reversing device 28 through the third pipeline and the fourth pipeline. The second reversing device 28 is connected with the top gun 26, and the gas main pipeline 27 is connected with the second reversing device 28. The first butterfly valve 16 is arranged on the third pipeline. The first butterfly valve 16 is a pneumatic or electric butterfly valve, which is used to control the opening and closing of the third pipeline, thereby realizing the control of the material receiving and stopping of the first powder spraying bin 17. The second butterfly valve 24 is arranged on the fourth pipeline. The second butterfly valve 24 is a pneumatic or electric butterfly valve, which is used to control the opening and closing of the fourth pipeline, thereby realizing the control of the material receiving and stopping of the second powder spraying bin 23.

[0044] As Figure 1 shown, the outlet of the first powder spraying bin 17 is provided with the ninth ball valve 18, which is connected with the second reversing device 28. The ninth ball valve 18 is used to control the opening and closing of the outlet of the first powder spraying bin 17, thereby realizing the control of the powder delivery. The outlet of the second powder spraying bin 23 is provided with the thirteenth ball valve 22, which is connected with the second reversing device 28. The thirteenth ball valve 22 is used to control the opening and closing of the outlet of the second powder spraying bin 23, thereby realizing the control of the powder delivery.

[0045] As Figure 1As shown, the first powder spraying bin 17 and the second powder spraying bin 23 are communicated with the top gun 26 through pipelines; the gas main pipeline 27 is communicated with the eighth ball valve 10 and the tenth ball valve 19, the eighth ball valve 10 and the tenth ball valve 19 are communicated with the second reversing device 28, the eighth ball valve 10 and the tenth ball valve 19 are located between the gas main pipeline 27 and the second reversing device 28, the eighth ball valve 10 and the tenth ball valve 19 are arranged in parallel, the eighth ball valve 10 and the tenth ball valve 19 are used for the cut-off and delivery control of the assist blowing gas, the ninth ball valve 18 and the eighth ball valve 10 are connected with the same port of the second reversing device 28, the tenth ball valve 19 and the thirteenth ball valve 22 are connected with the other same port of the second reversing device 28. The nineteenth ball valve 41 is arranged for the cut-off and delivery control of the protection gas, the nineteenth ball valve 41 is connected with the gas source for providing the protection gas and the top gun 26, and the nineteenth ball valve 41 is located between the gas source and the top gun 26. The twentieth ball valve 42 is arranged between the second reversing device 28 and the top gun 26, and the twentieth ball valve 42 is connected with the second reversing device 28 and the top gun 26.

[0046] As preferred, the first weighing bin 3 and the second weighing bin 5 and the first powder spraying bin 17 and the second powder spraying bin 23 are arranged on the same vertical axis or arranged on different vertical axes.

[0047] As shown in Figure 1 and Figure 2 The top gun 26 includes a top gun body 51, a main gas supply pipe 56, a water inlet pipe 52, a water return pipe 53 and a spraying hose 54 connected with the top gun body 51, and the spraying hose 54 is connected with the first powder spraying bin 17 and the second powder spraying bin 23. The top gun 26 is installed on the lifting trolley through a connecting device 55, and the spraying height can be adjusted. The spraying hose 54 is communicated with the first powder spraying bin 17, the second powder spraying bin 23 and the nineteenth ball valve 41 through pipelines, so as to realize the spraying of the powder into the furnace; the main gas supply pipe 56 is communicated with oxygen, nitrogen, argon, CO2 and other media, and oxygen, nitrogen, argon, CO2 and other media are introduced into the main gas supply pipe 56 according to the requirements, so as to realize the mixed spraying function of oxygen and nitrogen, argon, CO2 and other media.

[0048] As shown in Figure 3As shown, the top lance body 51 comprises a center tube 65, an intermediate tube 66, an inner tube 67 and an outer tube 68, the intermediate tube 66 is sleeved on the center tube 65, the inner tube 67 is sleeved on the intermediate tube 66, the outer tube 68 is sleeved on the inner tube 67, the center hole of the center tube 65 is a powder injection channel 61, the powder injection channel 61 is used for injecting powder, a main gas supply channel 62 is formed between the center tube 65 and the intermediate tube 66, the main gas supply channel 62 is used for supplying blowing gas, a cooling water inlet channel 63 is formed between the intermediate tube 66 and the inner tube 67, a cooling water return channel 64 is formed between the inner tube 67 and the outer tube 68, the cooling water return channel 64 is communicated with the water return pipe 53, the cooling water inlet channel 63 is communicated with the water inlet pipe 52, the powder injection channel 61 is communicated with the blowing hose 54, and the main gas supply channel 62 is communicated with the main gas supply pipe 56. Cooling water is introduced into the cooling water inlet channel 63, which is used for cooling the top lance 26. The diameters of the center tube 65, the intermediate tube 66, the inner tube 67 and the outer tube 68 increase in turn, the center tube 65, the intermediate tube 66, the inner tube 67 and the outer tube 68 are all coaxial cylindrical bodies, and the materials are container or boiler steels.

[0049] The application also provides a top lance multifunctional combined injection process for a converter, which adopts the top lance multifunctional combined injection equipment and comprises the following steps.

[0050] Step one: selection of powder and calculation of powder and natural gas requirements;

[0051] Step two: selection and determination of blowing scheme;

[0052] Step three: the converter is loaded with cold charge and molten iron, and the top lance 26 starts blowing;

[0053] Step four: smelting;

[0054] Step five: tapping;

[0055] Step six: after tapping, the converter is shaken to a vertical position, the lance is lowered and the slag is splashed to protect the furnace, the gas medium of the main gas supply channel 62 and the center powder injection channel 61 of the top lance 26 is nitrogen, the bottom blowing medium is switched to nitrogen, and the gas supply strength is increased;

[0056] Step seven: after slag splashing and protection, the slag is poured, the converter is shaken to a charging position, and the next smelting is started.

[0057] Specifically, in the above step one, the requirements of lime powder, carbonaceous powder for thermal compensation and natural gas are calculated according to the charging amount, composition, temperature and smelting steel grade requirements of the converter molten iron, scrap steel and other iron-containing metal materials.

[0058] In the above step two, the amount of lime powder injected by the top lance 26 is distributed according to the injection capacity (the top lance is used to add the powder from the powder bin when the top lance capacity is insufficient), the amount of carbonaceous powder injected by the top lance 26 is filled into the powder injection bin, the pressure in the first powder injection bin 17 and the second powder injection bin 23 is set to 0.40-1.80 MPa, and the type and flow of the gas medium in different stages are set.

[0059] In the above step three, after the converter is charged with scrap steel and other cold materials, the molten iron is added, the converter is shaken to be vertical to the converter mouth, and the top lance 26 is lowered to start the blowing.

[0060] The above step four includes:

[0061] Step 4.1: In the early stage of smelting, the gas injected by the main gas supply channel 62 of the top lance 26 is oxygen, a mixture of oxygen and carbon dioxide, a mixture of oxygen and nitrogen, or a mixture of oxygen and other inert gases, and the carrier gas of the powder injection channel 61 of the top lance 26 is a mixture of one or more of argon, nitrogen, and carbon dioxide;

[0062] Step 4.2: In the middle stage of smelting, the gas injected by the main gas supply channel 62 of the top lance 26 is oxygen, a mixture of oxygen and carbon dioxide, a mixture of oxygen and nitrogen, or a mixture of oxygen and other inert gases, and the carrier gas of the powder injection channel 61 of the top lance 26 is a mixture of one or more of oxygen, argon, nitrogen, and carbon dioxide;

[0063] Step 4.3: In the late stage of smelting, the powder injection of the top lance 26 is stopped, the gas injected by the main gas supply channel 62 of the top lance 26 is oxygen, a mixture of oxygen and carbon dioxide, or a mixture of oxygen and other inert gases, and the gas medium of the powder injection channel 61 of the top lance 26 is oxygen or a mixture of oxygen and carbon dioxide, argon.

[0064] In the above step two, if the lime powder and the carbonaceous powder for heat compensation are used for injection process, the first weighing bin 3 and the second weighing bin 5 can be filled with lime powder and carbonaceous powder respectively, and the powder in the first weighing bin 3 and the second weighing bin 5 can be mixed and transported to any one of the first powder injection bin 17 and the second powder injection bin 23 for mixed injection by the fluidized bed 25.

[0065] In particular, in the above step two, the powder in the first weighing bin 3 and the second weighing bin 5 can be transported to the first powder injection bin 17 or the second powder injection bin 23 for injection separately; the powder indicators require that the particle size of the lime powder is 20-2000 μm, and the water content is less than 0.5%; the particle size of the carbonaceous powder is 20-1000 μm, and the water content is less than 1.5%, which helps to improve the product quality.

[0066] In the above step five, after confirming that the tapping condition is reached, the top lance 26 is lifted, and the gas supply is stopped after reaching the opening and closing oxygen point, and the tapping is prepared.

[0067] In the above multi-functional combined injection process of the converter top lance 26, the maximum amount of the corresponding powder is as follows when single-injection of lime powder, single-injection of carbon powder, and lime powder + carbon powder injection are performed in one furnace:

[0068] (1) Single-injection of lime powder in one furnace;

[0069] In the early and middle stages of smelting, the top lance 26 sprays lime powder into the converter, and the maximum injection amount of lime powder LM=(7-12)×VL, wherein LM is the maximum injection amount of lime powder, VL is the maximum injection speed of lime powder, and the unit is kg / min; such a setting is helpful to improve product quality.

[0070] (2) Single-injection of carbon powder in one furnace;

[0071] In the early and middle stages of smelting, when the top lance 26 sprays carbon powder into the converter, the maximum injection amount of carbon powder CM=(8-15)×VC, wherein CM is the maximum injection amount of carbon powder, and VC is the maximum injection speed of carbon powder, and the unit is kg / min; such a setting is helpful to improve product quality.

[0072] (3) Lime powder + carbon powder injection in one furnace;

[0073] In the early and middle stages of smelting, when the top lance 26 sprays lime powder and carbon powder into the converter, the injection amount of lime powder is (4-12)×VL×0.70, and the injection amount of carbon powder is (4-12)×VC×0.3, VL is the maximum injection speed of lime powder, and the unit is kg / min, and VC is the maximum injection speed of carbon powder, and the unit is kg / min; such a setting is helpful to improve product quality.

[0074] In the above step 4.1, in order to improve the dephosphorization effect in the early stage, the main gas supply channel 62 of the top lance 26 uses one or more gases such as oxygen and nitrogen, carbon dioxide, and argon for mixed blowing, and the oxygen accounts for 40%-95% of the total gas supply amount; such a setting is helpful to improve product quality. If the nitrogen content at the end of the smelted steel grade is required to be not greater than 18 ppm, the mixed blowing gas in the main gas supply channel 62 of the top lance 26 does not contain nitrogen; such a setting is helpful to improve product quality. In particular, in the above step four, if the nitrogen content at the end of the smelted steel grade is required to be not greater than 15 ppm, the carrier gas of the central powder injection channel 61 of the top lance 26 is a nitrogen-free gas such as argon and carbon dioxide, which is helpful to improve product quality. If the nitrogen content at the end of the smelted steel grade is greater than 15 ppm, the carrier gas of the central powder injection channel 61 of the top lance 26 is a mixed gas formed by mixing one or more than two of nitrogen, argon, and carbon dioxide.

[0075] In the above step 4.2, in order to inhibit the evaporation of iron elements (and absorb carbon dioxide), the mixed gas of oxygen and one or more of nitrogen, carbon dioxide and argon is mixed and blown through the main gas supply channel 62 of the top lance 26, and the oxygen accounts for more than 70% of the total gas supply. This helps to improve the product quality. If the nitrogen content of the steel grade at the end of smelting is required to be not more than 22 ppm, the mixed gas of the main gas supply channel 62 of the top lance 26 does not contain nitrogen. This helps to improve the product quality. If the nitrogen content of the steel grade at the end of smelting is required to be not more than 18 ppm, the carrier gas of the center powder injection channel 61 of the top lance 26 is a nitrogen-free gas such as argon or carbon dioxide. This helps to improve the product quality.

[0076] In the above step four, the pressure in the first powder injection bin 17 and the second powder injection bin 23 is higher than the pressure in the center pipe 65 of the top lance 26 by more than 0.2 MPa, the gas supply intensity of the top lance 26 is 2.8-5.0 m 3 / (t.min), and the powder flow rate of the top lance 26 is 0.5-6 kg / (t.min). This helps to improve the product quality.

[0077] The above-mentioned multi-functional combined top lance 26 injection equipment and process have the following advantages:

[0078] (1) Through the unique design and configuration of the multi-functional combined high-efficiency injection metallurgical process and equipment, various types of solid-state powder and gaseous medium required for the injection of the top lance 26 can be realized individually or in proportion to "mixed injection", "flexible switching" and "mutual standby" of the injection equipment, so as to achieve the required various injection metallurgical targets in a more reliable and flexible manner.

[0079] (2) Through the unique design of the multi-functional combined high-efficiency injection process equipment of the top lance 26, it can achieve, for example, "mixed injection" of lime and biomass carbon in proportion, which can simultaneously achieve the purposes of reducing lime consumption and steel consumption, improving dephosphorization rate and steel quality, and improving scrap steel ratio and production efficiency.

[0080] (3) Through the unique design of the multi-functional combined high-efficiency injection process equipment of the top lance 26, it can also simultaneously achieve, for example, "flexible switching" of the function of absorbing CO2 to reduce dust emission, so as to achieve the purposes of improving the scrap steel ratio and production efficiency of the converter and "carbon reduction and emission reduction" high comprehensive benefit of green steelmaking.

[0081] (4) The system design is unique, and the top lance 26 can realize the injection smelting of oxygen, mixed gas of oxygen and carbon dioxide, oxygen and nitrogen, or oxygen and other inert gas through the main gas supply valve station and pipeline. The injection system, lance body and powder injection channel 61 of the nozzle have the functions of "flexible switching" of various powders and nitrogen, argon, CO2 and other types of gas for injection metallurgy.

[0082] (5) The weighing bin and the powder spraying bin can be arranged on the same vertical axis or on different vertical axes, which is compact and flexible.

[0083] (6) The unique design of the top gun 26 multi-functional combined high-efficiency spraying process equipment can realize, for example, "mutual standby" of the weighing bin and the spraying bin, redundancy, and strong system stability.

[0084] Embodiment

[0085] The embodiment provides a 150-ton converter top gun 26 multi-functional combined spraying equipment, the volume of the first weighing bin 3 and the second weighing bin 5 is 10m 3 , and the design pressure is 5000Pa; the volume of the first powder spraying bin 17 and the second powder spraying bin 23 is 6m 3 , and the design maximum pressure is 0.80Mpa.

[0086] The medium in the gas main pipeline 27 is nitrogen and argon, the purity is > 99.0%, and the pressure is 0.50-0.70Mpa.

[0087] The first ball valve 1, the second ball valve 2, the third ball valve 4, the fourth ball valve 6, the fifth ball valve 7, the sixth ball valve 8, the seventh ball valve 9, the eighth ball valve 10, the ninth ball valve 18, the tenth ball valve 19, the eleventh ball valve 20, the twelfth ball valve 21, the thirteenth ball valve 22, the fourteenth ball valve 29, the fifteenth ball valve 35, the sixteenth ball valve 36, the seventeenth ball valve 37, the eighteenth ball valve 38, the nineteenth ball valve 41 and the twentieth ball valve 42 are pneumatic or electric valves; the first gate valve 11 and the second gate valve 13 are pneumatic or electric valves; and the first butterfly valve 16 and the second butterfly valve 24 are pneumatic or electric valves.

[0088] The top of the first weighing bin 3 is communicated with the gas main pipeline 27 through the second ball valve 2, the first weighing bin 3 is provided with the first pressure detection device 30 and the eighteenth ball valve 38, the first weighing bin 3 can be filled with gas or discharged through the switch combination control of the first ball valve 1 and the eighteenth ball valve 38, and the pressure of the first weighing bin 3 can be adjusted. The top of the second weighing bin 5 is communicated with the gas main pipeline 27 through the third ball valve 4, the second weighing bin 5 is provided with the second pressure detection device 31 and the seventeenth ball valve 37, the second weighing bin 5 can be filled with gas or discharged through the switch combination control of the third ball valve 4 and the seventeenth ball valve 37, and the pressure of the second weighing bin 5 can be adjusted. The bottom of the first weighing bin 3 is communicated with inert gas (nitrogen or argon), so that the material is prevented from being hardened and kept in a fluidized state, the fluidized flow rate is 3m 3 / h, the bottom of the first weighing bin 3 is connected with the fourth ball valve 6, and the fourth ball valve 6 is used for gas cutting and conveying. The bottom of the second weighing bin 5 is communicated with inert gas (nitrogen or argon), so that the material is prevented from being hardened and kept in a fluidized state, the fluidized flow rate is 3m 3 / h, the bottom of the second weighing bin 5 is connected with the first ball valve 1, and the first ball valve 1 is used for gas shutoff and conveying.

[0089] The fourteenth ball valve 29 and the fifth pressure detecting device 34 are arranged on the gas main pipeline 27, the fourteenth ball valve 29 is used for gas shutoff and conveying control in the gas main pipeline 27, and the fifth pressure detecting device 34 is used for pressure measurement of the gas main pipeline 27, and an alarm is given when the pressure in the gas main pipeline 27 is lower than 0.45 Mpa or higher than 0.75 Mpa; the gas main pipeline 27 can be set to supply single or mixed medium such as nitrogen, argon and CO2 according to requirements and has an automatic switching function.

[0090] The first gate valve 11 and the first rotary feeder 12 are arranged between the outlet of the first weighing bin 3 and the first reversing device 15, the first rotary feeder 12 is located between the first gate valve 11 and the first reversing device 15, and the first gate valve 11 is used for closing the outlet of the first weighing bin 3 during maintenance. The first rotary feeder 12 is used for conveying the first powder discharged from the first weighing bin 3 to the first reversing device 15 and for controlling the discharging speed. The second gate valve 13 and the second rotary feeder 14 are arranged between the outlet of the second weighing bin 5 and the first reversing device 15, the second rotary feeder 14 is located between the second gate valve 13 and the first reversing device 15, and the second gate valve 13 is used for closing the outlet of the second weighing bin 5 during maintenance. The second rotary feeder 14 is used for conveying the second powder discharged from the second weighing bin 5 to the first reversing device 15 and for controlling the discharging speed. The discharging speed of the first weighing bin 3 and the second weighing bin 5 is controlled to be 500-700 kg / min.

[0091] The fluidized bed 25 uses low-pressure gas (such as nitrogen or argon) as carrier gas, the flow rate is 3 m 3 / h, the pressure is 0.30-0.70 MPa, and the powder moves into the first powder spraying bin 17 and the second powder spraying bin 23 along the fluidized bed 25 by gravity.

[0092] The top of the first powder spraying bin 17 is communicated with the gas main pipeline 27 through the sixth ball valve 8 and the auxiliary pipeline, the third pressure detecting device 32 and the fifteenth ball valve 35 are arranged on the first powder spraying bin 17, and the first powder spraying bin 17 can be inflated and deflated by gas and the pressure of the first powder spraying bin 17 can be adjusted through the on-off combination control of the sixth ball valve 8 and the fifteenth ball valve 35. The top of the second powder spraying bin 23 is communicated with the gas main pipeline 27 through the twelfth ball valve 21 and the auxiliary pipeline, the fourth pressure detecting device 33 and the sixteenth ball valve 36 are arranged on the first powder spraying bin 17, and the second powder spraying bin 23 can be inflated and deflated by gas and the pressure of the second powder spraying bin 23 can be adjusted through the on-off combination control of the twelfth ball valve 21 and the sixteenth ball valve 36.

[0093] The bottom of the first powder spraying bin 17 is connected with inert gas (nitrogen or argon, etc.) to keep the material in the bin in a fluidized state, and the fluidized flow rate is 2 m 3 / h. The bottom of the first powder spraying bin 17 is connected with the seventh ball valve 9, which is used for gas shutoff and delivery, and the seventh ball valve 9 is connected with the gas main pipeline 27. The bottom of the second powder spraying bin 23 is connected with inert gas (nitrogen or argon, etc.) to keep the material in the bin in a fluidized state, and the fluidized flow rate is 2 m 3 / h. The bottom of the second powder spraying bin 23 is connected with the eleventh ball valve 20, which is used for gas shutoff and delivery, and the eleventh ball valve 20 is connected with the gas main pipeline 27.

[0094] In the embodiment, the center pipe 65, the intermediate pipe 66, the inner pipe 67 and the outer pipe 68 are coaxial cylindrical barrels. The diameters of the center pipe 65, the intermediate pipe 66, the inner pipe 67 and the outer pipe 68 are φ76.1 mm, φ194 mm, φ248 mm and φ299 mm respectively. The sizes of the center pipe 65, the intermediate pipe 66, the inner pipe 67 and the outer pipe 68 are 7.1 mm, 10 mm, 7 mm and 9 mm respectively. The materials of the center pipe 65, the intermediate pipe 66, the inner pipe 67 and the outer pipe 68 are all 16Mn.

[0095] The embodiment provides a 150-ton converter top gun 26 multifunctional combined injection process, which comprises the following steps:

[0096] Step one: lime powder and carbonaceous powder dosage calculation. According to the charging amount, composition, temperature and steel grade requirement of the converter molten iron, scrap steel and other iron-containing metal materials, the required amounts of lime powder and carbonaceous powder for heat compensation are calculated to be 4700 kg and 1100 kg respectively.

[0097] Step two: selection and determination of injection scheme. According to the injection capacity, the amount of lime powder injected into the top gun 26 is distributed (the top gun 26 is used to add the material in the bin when the top injection capacity is insufficient), and the amount of carbonaceous powder injected into the top gun 26 is filled into the powder spraying bin. The pressures in the first powder spraying bin 17 and the second powder spraying bin 23 are 0.40-0.70 MPa. The types and flow rates of gas injection media in different stages are set.

[0098] Step three: after the converter is charged with scrap steel and other cold materials, the molten iron is poured, the converter is shaken to be vertical to the furnace mouth, and the top gun 26 is lowered to start blowing.

[0099] Step 4.1: in order to improve the dephosphorization effect in the early stage, the top gun 26 main gas supply channel 62 adopts oxygen and nitrogen mixed blowing (the nitrogen content at the end of the steel grade is required to be not greater than 20 ppm), and the oxygen accounts for 70% of the total gas supply amount (the total gas supply amount is 35000 m 3 / h, wherein the oxygen amount is 24500 m 3 / h); the carrier gas of the center powder spraying channel 61 of the top gun 26 is nitrogen, and the nitrogen flow rate is 300 m3 / h;

[0100] Step 4.2: In the middle of smelting, in order to inhibit the evaporation of iron element, the top lance 26 main gas supply channel 62 uses oxygen and carbon dioxide mixed blowing, and the oxygen accounts for 90% of the total gas supply (the total amount is 35000m3 / h, of which the oxygen is 31500m3 / h); the center powder injection channel 61 carries nitrogen gas, and the flow is 300m3 / h.

[0101] Step 4.3: In the late stage of smelting, stop powder injection, the top lance 26 main gas supply channel 62 sprays oxygen and carbon dioxide (the total gas supply is 33000m 3 / h, of which the oxygen amount is 29700m 3 / h), the center powder injection channel 61 of the top lance 26 gas medium is oxygen, and the oxygen flow is 600m 3 / h;

[0102] Step five: after confirming that the tapping condition is reached, the top lance 26 is lifted to the opening and closing oxygen point, and then the gas supply is stopped to prepare for tapping;

[0103] Step six: after tapping, the converter is shaken to the vertical position, the lance is lowered to splash slag for furnace protection, the gas medium of the top lance 26 main blowing channel and the center powder injection channel 61 is nitrogen, the bottom blowing medium is switched to nitrogen, and the gas supply intensity is increased;

[0104] Step seven: after slag splashing for furnace protection, the slag is poured, the converter is shaken to the charging position, and the next furnace smelting is started.

[0105] Further, the pressure in the first powder injection bin 17 and the second powder injection bin 23 is higher than the pressure in the center pipe 65 by more than 0.2MPa, the gas supply intensity is 3.8m 3 / (t.min), and the powder carrying capacity is 3.4kg / (t.min).

[0106] In the above step two, a lime powder and carbonaceous powder injection process is used, the first weighing bin 3 and the second weighing bin 5 are respectively filled with lime powder and carbonaceous powder, and the first powder from the first weighing bin 3 and the second powder from the second weighing bin 5 are mixed by the fluidized bed 25 and then transported to any one of the first powder injection bin 17 and the second powder injection bin 23 for mixing and injection; the mixing ratio can be arbitrarily adjusted. In this embodiment, the weight ratio of the first powder and the second powder is 7:3.

[0107] In this embodiment, the injection scheme uses a lime powder + carbonaceous powder injection scheme per furnace.

[0108] In the early and middle stages of smelting, the lime powder is injected into the converter by the top lance 26, the total injection time is 10 minutes, the maximum injection speed of lime powder VL=500 kg / min, the injection amount of lime powder =10*VL*0.70=3500 kg; wherein the lime powder with a weight of 1200 kg is directly put into the converter by the stock bin.

[0109] In the early and middle stages of smelting, the carbonaceous powder is injected into the converter by the top lance 26, the total injection time is 10 minutes, the maximum injection speed of carbonaceous powder VL=400 kg / min, then the injection amount of carbonaceous powder =1200 kg, and the carbonaceous powder can be injected through the lance.

[0110] By the injection equipment and injection process of the embodiment, the lime consumption can be reduced by >3 kg / t, the dephosphorization rate can be increased by >5.0%, and the steel material consumption can be reduced by >1.0 kg / t.

[0111] The application is described above with reference to the drawings. It is clear that the specific implementation of the application is not limited to the above manner. Any non-essential improvement made by using the method concept and technical scheme of the application, or the direct application of the above concept and technical scheme of the application to other occasions without improvement, is within the protection scope of the application.

Claims

1. A multi-functional combined injection device for converter top lance, comprising a main gas pipeline and a top lance, characterized in that, It also includes a first weighing chamber for containing a first powder, a second weighing chamber for containing a second powder, a fluidized bed connected to the first and second weighing chambers, and a first and second powder spraying chamber connected to the fluidized bed. The first and second weighing chambers are connected to the main gas pipeline, and the first and second powder spraying chambers are connected to the top gun. The first powder is a lime powder or a carbonaceous powder, and the second powder is a lime powder or a carbonaceous powder. The fluidized bed is connected to the first reversing device, the first reversing device is connected to the first weighing chamber and the second weighing chamber, and the fluidized bed is connected to the first powder spraying chamber and the second powder spraying chamber through the first pipeline and the second pipeline, respectively. A first gate valve and a first rotary feeder are provided between the outlet of the first weighing bin and the first reversing device, and a second gate valve and a second rotary feeder are provided between the outlet of the second weighing bin and the first reversing device. The first powder spraying chamber and the second powder spraying chamber are respectively connected to the second reversing device through the third pipeline and the fourth pipeline. The second reversing device is connected to the top gun, and the main gas pipeline is connected to the second reversing device. The top gun includes a top gun body and a main air supply pipe, a water inlet pipe, a water return pipe, and a spray hose connected to the top gun body. The spray hose is connected to the first powder spraying chamber and the second powder spraying chamber. The top gun body includes a central tube, an intermediate tube, an inner tube, and an outer tube. The intermediate tube is sleeved on the central tube, the inner tube is sleeved on the intermediate tube, and the outer tube is sleeved on the inner tube. A powder spraying channel is provided on the central tube. A main air supply channel is formed between the central tube and the intermediate tube. A cooling water inlet channel is formed between the intermediate tube and the inner tube. A cooling water return channel is formed between the inner tube and the outer tube. The cooling water return channel is connected to the return water pipe. The cooling water inlet channel is connected to the inlet water pipe. The powder spraying channel is connected to the spraying hose. The main air supply channel is connected to the main air supply pipe.

2. The converter top lance multi-functional combined spraying device according to claim 1, characterized in that, The central tube, the intermediate tube, the inner tube, and the outer tube are all coaxial cylindrical bodies made of container or boiler steel.

3. The converter top lance multi-functional combined spraying process is characterized by, The converter top lance multi-functional combined injection device as described in claim 1 or 2 is used, and includes the following steps: Step 1: Selection of powder and calculation of powder and natural gas demand; Step Two: Selection and Determination of the Pulse Jetting Scheme; Step 3: The converter is loaded with cold material and molten iron, and the top lance begins the blowing process; Step 4: Smelting; Step 5: Tap the steel.

4. The converter top lance multi-functional combined injection process according to claim 3, characterized in that, Step four includes: Step 4.1: In the early stage of smelting, the blowing gas of the main gas supply channel of the top gun is a mixture of oxygen, oxygen and carbon dioxide, oxygen and nitrogen, or oxygen and other inert gases. The carrier gas of the powder injection channel of the top gun is a mixture of one or more of argon, nitrogen, and carbon dioxide. Step 4.2: During the middle stage of smelting, the blowing gas of the main gas supply channel of the top gun is a mixture of oxygen, oxygen and carbon dioxide, oxygen and nitrogen, or oxygen and other inert gases. The carrier gas of the powder injection channel of the top gun is a mixture of one or more of the following gases: oxygen, argon, nitrogen, and carbon dioxide. Step 4.3: In the later stage of smelting, the blowing gas of the main gas supply channel of the top gun is oxygen, oxygen and carbon dioxide or oxygen and other inert gases, and the gas medium of the powder injection channel of the top gun is oxygen or oxygen and carbon dioxide and argon.

5. The converter top lance multi-functional combined injection process according to claim 3, characterized in that, In step two, if a lime powder and thermal compensation carbonaceous powder spraying process is used, the first weighing bin and the second weighing bin can be filled with lime powder and carbonaceous powder respectively. The powders in the first weighing bin and the second weighing bin are mixed and transported to either the first spraying bin or the second spraying bin for mixed spraying through the fluidized bed.

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