Tuyere nose of hydrogen-rich carbon-recycling oxygen blast furnace and control method

Abstract

The present invention belongs to the technical field of blast furnace smelting. Specifically disclosed are a tuyere nose of a hydrogen-rich carbon-recycling oxygen blast furnace and a control method. The tuyere nose is configured to be a tuyere nose comprising a tuyere body, a tuyere front end, and an oxygen channel, wherein the tuyere body and a tuyere front end surface are welded together at a front end welding interface; the oxygen channel is arranged in the tuyere body and extends from an inner side of the tuyere front end; and an oxygen nozzle orifice of the oxygen channel is maintained at a distance of 20-50 mm from the tuyere front end surface, and the oxygen nozzle orifice forms an included angle of 25-30° with a tuyere center line. During normal operation of the blast furnace, the flow rate at the oxygen nozzle orifice is controlled to be not less than 150 m / s, and the distance between a front end high-temperature region of the tuyere body and the tuyere front end surface is controlled to be not less than 200 mm. By means of the tuyere nose of the hydrogen-rich carbon-recycling oxygen blast furnace and by using the control method, the blast furnace can be effectively prevented from burning loss, and the ironmaking efficiency of the blast furnace can be improved.

Description

Hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve and control method TECHNICAL FIELD

[0001] The present application relates to the field of blast furnace smelting technology, in particular to a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve and control method. BACKGROUND

[0002] 70% of the energy consumption of a steel enterprise is concentrated in the ironmaking process, so reducing the carbon consumption of the ironmaking process is the main way to achieve coal reduction in the steel industry. The existing traditional blast furnace process has been developed for several hundred years and has the characteristics of high thermal efficiency, large production capacity and perfect technology. However, it has also encountered a development bottleneck, and the space for further reducing the fuel consumption of molten iron is very limited, and the large-scale of blast furnace to improve production efficiency has reached the limit.

[0003] The hydrogen-rich carbon-circulation oxygen blast furnace adopts full-oxygen smelting and top-coal-gas decarburization heating and recycling technology, which reduces the fossil energy consumption of the traditional blast furnace process by 30%. However, due to the characteristics of full-oxygen smelting and coal gas heating and recycling technology, the blast furnace tuyere is prone to melting and damage under the complex working conditions of high temperature, oxidation, coal powder injection and high temperature molten slag and iron in the furnace, thereby affecting the normal operation of the blast furnace. SUMMARY

[0004] The purpose of the present application is to provide a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve and control method to solve the problem of easy melting and damage of the hydrogen-rich carbon-circulation oxygen blast furnace tuyere.

[0005] To achieve the above-mentioned purpose, the present application provides a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve, which comprises a tuyere body, a tuyere front end face and an oxygen channel, comprising:

[0006] The tuyere body comprises a high-temperature coal gas channel and a tuyere cooling water channel, the high-temperature coal gas channel is arranged at the center position of the tuyere body, and the tuyere cooling water channel is arranged at one side of the tuyere body; the front end of the tuyere body is welded to the front end welding interface of the tuyere front end face;

[0007] The diameter of the high-temperature coal gas channel is selected to be 50-120mm; according to the size of the blast furnace and the gas flow rate at the tuyere, the gas flow rate at the tuyere is required to be not less than 150 / s, and the gas flow rate during normal load operation of the high-temperature is preferably not less than 200m / s;

[0008] The gas flow rate of the high-temperature coal gas channel above 1100 DEG C during production is greater than or equal to 200m / s, and the gas in the high-temperature coal gas channel can be selected from the blast furnace self-circulation decarburization coal gas, the hydrogen-rich coke oven gas or the mixed gas of the above two kinds of coal gas;

[0009] The length of the tuyere small sleeve is 6-8% of the inner diameter of the blast furnace hearth, preferably 7%; the lower limit is preferred for blast furnaces above 1000 cubic meters, and the upper limit is preferred for blast furnaces below 1000 cubic meters.

[0010] The oxygen channel is arranged in the tuyere body and extends from the inner side of the front end of the tuyere body, and the oxygen channel comprises an oxygen inlet and an oxygen nozzle, the oxygen inlet and the oxygen nozzle are arranged at the two ends of the oxygen channel respectively, the distance between the oxygen nozzle and the tuyere front end surface is 20-50mm, the oxygen nozzle is located at a position 30-45° below the horizontal line, and the distance between the oxygen nozzle and the inserted coal injection gun port is greater than or equal to 50mm, and the angle between the oxygen nozzle and the tuyere center line is 25-30°.

[0011] The tuyere small sleeve comprises a tuyere body, a tuyere front end surface and an oxygen channel, the tuyere body comprises a high-temperature gas channel and a tuyere cooling water channel, the high-temperature gas channel is arranged at the center position of the tuyere body to ensure that the gas passes through the tuyere small sleeve smoothly, the tuyere cooling water channel is arranged on one side of the tuyere body to cool the tuyere small sleeve and avoid high-temperature melting, the oxygen channel is arranged in the tuyere body and extends from the inner side of the front end of the tuyere body, the distance between the oxygen nozzle of the oxygen channel and the tuyere front end surface and the oxygen blowing angle are set to avoid high-temperature reaction between oxygen and gas and cause melting of the tuyere small sleeve, and the safe and stable operation of the hydrogen-rich carbon cycle oxygen blast furnace tuyere area is ensured.

[0012] Preferably, the distance between the front end welding interface and the oxygen nozzle is not less than 20mm, and the welding depth of the front end welding interface is not less than 20mm.

[0013] The oxygen channel and the tuyere body are integrally cast, and then welded with the tuyere front end surface, the welding material needs to be selected to have a thermal conductivity not less than that of the base material, and needs to pass the water flow strength test of not less than 2Mpa.

[0014] The distance between the front end welding interface and the oxygen nozzle is controlled to avoid the problem of melting of the front end welding interface caused by too close distance between the two, and the welding depth of the front end welding interface is strengthened to increase the high-temperature resistance of the front end welding interface.

[0015] Preferably, after the front end welding interface is welded, a layer of high-temperature and wear-resistant protective layer is added to the front end welding interface.

[0016] By adding a layer of high-temperature and wear-resistant protective layer to the front end welding interface, the protection of the small sleeve end surface and the weld is completed, and the high-temperature resistance of the front end welding interface is increased.

[0017] The application also provides a control method of a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve.

[0018] By controlling the flow rate of oxygen at the oxygen nozzle and the distance between the front end high-temperature zone of the tuyere body and the tuyere front end face, the front end high-temperature zone is kept away from the tuyere front end face, so that the high-temperature damage of the tuyere caused by the combustion reaction of the oxygen stream and the high-temperature coal gas stream in the tuyere area is avoided, the blast furnace downtime rate is reduced, and the blast furnace ironmaking efficiency is improved.

[0019] Preferably, during the initial stage of starting the blast furnace or the low-load operation, and under the condition that the oxygen amount is lower than the preset normal value, the number of oxygen inlets is controlled, the oxygen flow rate in the oxygen inlets is kept not less than 150 m / s, and 100-300 of nitrogen is introduced into the oxygen inlets.

[0020] By controlling the number of oxygen inlets and supplementing nitrogen, the oxygen flow rate in the oxygen inlets is kept not less than 150 m / s, so as to ensure the safe and stable operation of the hydrogen-rich carbon-circulation oxygen blast furnace tuyere area.

[0021] Preferably, before oxygen is fed into the hydrogen-rich carbon-circulation oxygen blast furnace, the heating gas or nitrogen in the high-temperature coal gas passage must be adjusted to more than 40% of the total air volume, and the gas flow rate in the high-temperature coal gas passage is not less than 150 m / s.

[0022] By adjusting the air volume of the heating gas or nitrogen in the high-temperature coal gas passage before oxygen is fed into the blast furnace, and controlling the gas flow rate in the high-temperature coal gas passage, an operation basis is provided for the stable operation of the blast furnace tuyere area after oxygen is fed.

[0023] Preferably, before oxygen is fed into the hydrogen-rich carbon-circulation oxygen blast furnace, not less than 500 of nitrogen is first introduced into the oxygen passage, then oxygen is supplemented into the oxygen passage, and the oxygen flow rate in the oxygen passage is kept not less than 150 m / s, when the oxygen in the oxygen passage increases to more than 70% of the set oxygen amount, the nitrogen in the oxygen passage is gradually removed, and the flow rate in the oxygen passage is kept not less than 150 m / s throughout the process.

[0024] By first introducing nitrogen into the oxygen passage before feeding oxygen, then supplementing oxygen into the oxygen passage, and controlling the oxygen flow rate in the oxygen passage, when the oxygen in the oxygen passage increases to more than 70% of the set oxygen amount, the nitrogen in the oxygen passage is gradually removed, so as to ensure the concentration of oxygen in the oxygen passage.

[0025] The application provides a tuyere small sleeve provided with a tuyere body, a tuyere front end and an oxygen channel, the tuyere body and the tuyere front end are welded at a front end welding interface, the oxygen channel is arranged in the tuyere body and led out from the inside of the tuyere front end, an oxygen nozzle port of the oxygen channel is kept at a distance of 20-50 cm from the tuyere front end and forms an included angle of 25-30°, the oxygen nozzle port is located at a position 30-45 degrees below the horizontal line and is kept at a distance of not less than 50 mm from the inserted coal injection gun port, the flow rate of the oxygen nozzle port is controlled to be not less than 150 m / s during the normal operation of the blast furnace, the included angle matches the flow rate and angle of the oxygen flow of the oxygen channel and the gas flow of the high-temperature gas channel, and the high-temperature zone of the tuyere front end is away from the end face of the tuyere front end, by using the above-mentioned hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve and the above-mentioned control method, the burning loss of the blast furnace can be effectively prevented, and the ironmaking efficiency of the blast furnace is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a cross-sectional structure schematic view of a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve provided by the application;

[0027] Fig. 2 is a cross-sectional plane structure schematic view of a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve provided by the application;

[0028] Fig. 3 is a cross-sectional schematic view of an oxygen nozzle port in an oxygen channel;

[0029] Fig. 4 is a cross-sectional schematic view of an oxygen inlet port in an oxygen channel. DETAILED DESCRIPTION

[0030] The application will be further described in detail through specific embodiments:

[0031] The reference signs in the drawings of the specification include:

[0032] 1, oxygen channel; 2, oxygen inlet port; 3, oxygen nozzle port; 4, tuyere body; 5, high-temperature gas channel; 6, tuyere cooling water channel; 7, cooling water channel; 8, tuyere front end face; 9, front end welding interface; 10, injected gas inlet port; 11, cooling water inlet port; 12, cooling water outlet port; 13, tuyere small sleeve fixing groove. EMBODIMENT

[0033] As shown in Fig. 1, the embodiment of the application proposes a hydrogen-rich carbon-circulation oxygen blast furnace tuyere small sleeve, the tuyere small sleeve includes a tuyere body 4, a tuyere front end face 8 and an oxygen channel 1, which includes:

[0034] The tuyeres body 4 includes a high-temperature gas channel 5 and a tuyeres cooling water channel 6. The high-temperature gas channel 5 is located at the center of the tuyeres body 4, and the tuyeres cooling water channel 6 is located on one side of the tuyeres body 4. Cooling water channels 7 are provided in the tuyeres cooling water channel 6, and a cooling water channel 7 is also provided above the oxygen channel 1. The front end of the tuyeres body 4 is welded to the front end face 8 of the tuyeres at the front weld joint 9. The diameter of the high-temperature gas channel 5 is selected as 50mm; the total length of the tuyeres sleeve is set to 6% of the inner diameter of the blast furnace hearth (the blast furnace volume is over 1000 cubic meters, so the lower limit is used). High-temperature gas enters the high-temperature gas channel 5 through the injection gas inlet 10.

[0035] Oxygen channel 1 is located inside the tuyer body 4 and extends from the inner front end of the tuyer body 4. Oxygen channel 1 includes an oxygen inlet 2 and an oxygen nozzle 3. The oxygen inlet 2 and the oxygen nozzle 3 are respectively located at both ends of oxygen channel 1. The oxygen nozzle 3 is 20mm away from the front end face 8 of the tuyer, is located at a position 30° below the horizontal line, and is 50mm away from the inserted coal injection nozzle. The oxygen nozzle 3 forms a 25° angle with the center line of the tuyer. Oxygen channel 1 is integrally formed by vacuum casting. The distance between the front weld joint 9 and the oxygen nozzle 3 is 20mm, and the weld depth of the front weld joint 9 is 20mm, as shown in Figures 3 and 4. The inlet end of oxygen channel 1 is thicker than the outlet end, i.e., the oxygen inlet 2 is thicker and the oxygen nozzle 3 is thinner. The diameter of the oxygen inlet 2 can be selected as 35mm, and the diameter of the oxygen nozzle 3 as 26mm.

[0036] To protect the end face of the small sleeve and the weld, in this embodiment of the invention, after the front end face 8 of the air outlet is welded to the air outlet body 4, a high-temperature and wear-resistant protective layer is welded to the front weld joint 9.

[0037] Figure 2 is a schematic diagram of the left-side plan view of the above-mentioned hydrogen-rich carbon-circulating oxygen blast furnace tuyeres. It can be seen that a cooling water inlet 11 and a cooling water outlet 12 are set on the left side of the tuyeres. The cooling water inlet 11 and the cooling water outlet 12 are contained in the tuyeres cooling water channel 6 for the introduction and output of cooling water. An oxygen inlet 2 is set at the upper part of the tuyeres, an oxygen nozzle 3 is set at the center of the tuyeres, and a pulverized coal gas inlet 10 is set at a position slightly below the center of the tuyeres. High-temperature coal gas is introduced into the high-temperature coal gas channel 5 through the pulverized coal gas inlet 10. A tuyeres fixing groove 13 is set at the lower part of the tuyeres for fixing the tuyeres.

[0038] This invention also provides a control method for the small jacket of the hydrogen-rich carbon-circulating oxygen blast furnace tuyeres based on the above design, specifically including:

[0039] During normal operation of the hydrogen-rich carbon-cycle oxygen blast furnace tuyeres, the oxygen flow velocity at oxygen nozzle 3 is controlled at 150 m / s, and the distance between the high-temperature zone at the front end of the tuyer body 4 and the front end face 8 of the tuyeres is 200 mm. This is to prevent the oxygen stream from burning and reacting with the high-temperature coal stream in the tuyer area, which would cause high-temperature damage to the tuyeres, reduce the blast furnace shutdown rate, and improve the blast furnace ironmaking efficiency.

[0040] During the initial start-up or low-load operation, when the oxygen flow rate is lower than the preset normal value, control the number of oxygen inlets 2, maintain the oxygen flow rate in oxygen inlets 2 at 150 m / s, and introduce 100 m³ of oxygen into oxygen inlets 2. 3 / h of nitrogen gas.

[0041] Before oxygen is supplied to the hydrogen-rich carbon-cycle oxygen blast furnace, the heating gas or nitrogen in the high-temperature gas channel 5 needs to be adjusted to 40% of the total air volume, and the airflow velocity in the high-temperature gas channel 5 needs to be above 150m / s, so as to provide an operational basis for the stable operation of the blast furnace tuyeres area after oxygen supply.

[0042] Before supplying oxygen to the hydrogen-rich carbon-circulating oxygen blast furnace, the process also includes: first introducing 500m³ of oxygen into oxygen channel 1. 3 Nitrogen gas is supplied at a rate of / h, and oxygen is then added to oxygen channel 1, maintaining an oxygen flow rate of over 150m / s in oxygen channel 1. When the oxygen in oxygen channel 1 increases to 70% of the set oxygen quantity, the nitrogen gas in oxygen channel 1 is gradually withdrawn. Throughout the process, the flow rate in oxygen channel 1 is maintained at over 150m / s to ensure the oxygen concentration in oxygen channel 1.

[0043] By utilizing the aforementioned hydrogen-rich carbon-circulating oxygen blast furnace tuyeres and applying the aforementioned control methods, blast furnace burn-out can be effectively prevented and blast furnace ironmaking efficiency improved. Example

[0044] The specific implementation method is the same as that in Example 1, except for the following parts:

[0045] 1. The diameter of the high-temperature gas channel 5 is selected as 120mm; the length of the tuyeres is set to 8% of the diameter of the blast furnace hearth (the upper limit is taken for blast furnace volumes of 1000 cubic meters or more).

[0046] 2. The oxygen nozzle 3 is 50mm away from the front end face 8 of the air outlet. The oxygen nozzle 3 is located at a 45° position below the horizontal line and is 70mm away from the inserted coal injection gun. The oxygen nozzle 3 forms a 30° angle with the center line of the air outlet.

[0047] 3. The oxygen channel 1 is integrally formed by vacuum casting. The distance between the front welding port 9 and the oxygen nozzle port 3 is 40mm, and the weld depth of the front welding port 9 is 40mm.

[0048] 4. During normal operation of the hydrogen-rich carbon circulating oxygen blast furnace tuyeres, the oxygen flow velocity at oxygen nozzle 3 is controlled at 170 m / s, and the distance between the high-temperature zone at the front end of the tuyeres body 4 and the front end face 8 of the tuyeres is 220 mm.

[0049] 5. During the initial start-up or low-load operation, control the number of oxygen inlets 2, maintaining an oxygen flow rate of 170 m / s in oxygen inlet 2, and introduce 300 m³ of oxygen into oxygen inlet 2. 3 / h of nitrogen;

[0050] 6. Before supplying oxygen to the hydrogen-rich carbon circulating oxygen blast furnace, the heating gas or nitrogen in the high-temperature gas channel 5 needs to be adjusted to 60% of the total air volume, and the airflow velocity in the high-temperature gas channel 5 should be 170m / s.

[0051] 7. Before supplying oxygen to the hydrogen-rich carbon-circulating oxygen blast furnace, 700m³ of oxygen can be introduced into oxygen channel 1 first. 3 Nitrogen gas is supplied at a rate of / h, and oxygen is then added to oxygen channel 1 while maintaining an oxygen flow rate of 170m / s in oxygen channel 1. When the oxygen in oxygen channel 1 increases to 90% of the set oxygen quantity, the nitrogen gas in oxygen channel 1 is gradually withdrawn. Throughout the process, the flow rate in oxygen channel 1 is maintained at 170m / s to ensure the oxygen concentration in oxygen channel 1. Example

[0052] The specific implementation method is the same as that in Example 1, except for the following parts:

[0053] 1. The diameter of the high-temperature gas channel 5 is selected as 85mm; the length of the tuyeres is set to 7% of the diameter of the blast furnace hearth (the blast furnace volume is 1000 cubic meters).

[0054] 2. The oxygen nozzle 3 is 35mm away from the front end face 8 of the air outlet. The oxygen nozzle 3 is located at a position 40° below the horizontal line and is 60mm away from the inserted coal injection gun nozzle. The oxygen nozzle 3 forms a 27° angle with the center line of the air outlet.

[0055] 3. The oxygen channel 1 is integrally formed by vacuum casting. The distance between the front welding port 9 and the oxygen nozzle port 3 is 30mm, and the weld depth of the front welding port 9 is 30mm.

[0056] 4. During normal operation of the hydrogen-rich carbon circulating oxygen blast furnace tuyeres, the oxygen flow velocity at oxygen nozzle 3 is controlled at 160 m / s, and the distance between the high-temperature zone at the front end of the tuyeres body 4 and the front end face 8 of the tuyeres is 210 mm.

[0057] 5. During the initial start-up or low-load operation, control the number of oxygen inlets 2, maintaining an oxygen flow rate of 160 m / s in oxygen inlet 2, and introduce 200 m³ of oxygen into oxygen inlet 2. 3 / h of nitrogen;

[0058] 6. Before supplying oxygen to the hydrogen-rich carbon circulating oxygen blast furnace, the heating gas or nitrogen in the high-temperature gas channel 5 needs to be adjusted to 50% of the total air volume, and the airflow velocity in the high-temperature gas channel 5 should be 160m / s.

[0059] 7. Before supplying oxygen to the hydrogen-rich carbon-circulating oxygen blast furnace, 600m³ of oxygen can be introduced into oxygen channel 1 first. 3 Nitrogen gas is supplied at a rate of / h, and oxygen is then added to oxygen channel 1 while maintaining an oxygen flow rate of 160m / s in oxygen channel 1. When the oxygen in oxygen channel 1 increases to 80% of the set oxygen quantity, the nitrogen gas in oxygen channel 1 is gradually withdrawn. Throughout the process, the flow rate in oxygen channel 1 is maintained at 160m / s to ensure the oxygen concentration in oxygen channel 1.

[0060] This patented technology considers the impact of high-temperature coal gas and injected oxygen on the front face of the vent in its design. Firstly, in terms of flow rate control, the flow rate of oxygen and high-temperature coal gas is required to be no less than 150m / s, and preferably above 200m / s. Under high-speed airflow, the high-temperature zone of the reaction between the two is far away from the vent end face, reducing the risk of vent burn-out.

[0061] In terms of structural layout, the oxygen nozzle is positioned 30-45° below the horizontal line. Compared with the traditional method of arranging oxygen nozzles at the top, this arrangement is well adapted to the spatial structure characteristics of the counterclockwise circulation from bottom to top formed at the front of the air outlet. The injected oxygen can circulate to the end away from the air outlet as soon as possible, reducing the impact on the front surface.

[0062] With a distance of 50mm or more from the inserted pulverized coal nozzle, this layout eliminates the problem of oxygen from the oxygen nozzle burning the pulverized coal nozzle. The oxygen nozzle orifice forms a 25-30° angle with the center line of the tuyeres, further eliminating the influence of the oxygen stream on the pulverized coal stream and eliminating the problem of pulverized coal wear on the tuyeres caused by the oxygen stream blowing the pulverized coal stream off course.

[0063] This patented technology also makes good use of nitrogen replenishment measures. During the blast furnace start-up and shutdown periods, in order to ensure gas flow rate and system safety, nitrogen is injected to effectively solve the problem of insufficient gas and oxygen flow rate during start-up and shutdown periods, and eliminate the problem of tuyeres damage caused during shutdown and shutdown periods.

[0064] During the trial period, this patented technology was applied to the 430 cubic meter hydrogen-rich carbon-circulating oxygen blast furnace of Baosteel, increasing the service life of the tuyere from 1 month to 3 months and ensuring the smooth and stable operation of the blast furnace. It has now been extended to the 2500 cubic meter hydrogen-rich carbon-circulating oxygen blast furnace, where the service life of the tuyere has exceeded 5 months, effectively supporting the industrial production of the world's largest and only hydrogen-rich carbon-circulating oxygen blast furnace.

[0065] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A small sleeve for a hydrogen-rich carbon-circulating oxygen blast furnace tuyere, characterized in that, The air vent sleeve includes an air vent body (4), an air vent front face (8), and an oxygen channel (1), comprising: The air outlet body (4) includes a high-temperature gas channel (5) and an air outlet cooling water channel (6). The high-temperature gas channel (5) is located at the center of the air outlet body (4), and the air outlet cooling water channel (6) is located on one side of the air outlet body (4). The front end of the air outlet body (4) is welded to the front end face (8) of the air outlet at the front end weld joint (9). The diameter of the high-temperature gas channel (5) is selected to be 50-120mm; The total length of the tuyeres sleeve is set to 6-8% of the blast furnace hearth inner diameter; The oxygen channel (1) is located inside the air outlet body (4) and extends out from the inner front end of the air outlet body (4). The oxygen channel (1) includes an oxygen inlet (2) and an oxygen nozzle (3). The oxygen inlet (2) and the oxygen nozzle (3) are respectively located at both ends of the oxygen channel (1). The oxygen nozzle (3) is 20-50mm away from the front end face (8) of the air outlet. The oxygen nozzle (3) is located at a position 30-45° below the horizontal line and is at a distance greater than or equal to 50mm from the inserted coal injection gun nozzle. The oxygen nozzle (3) forms an angle of 25-30° with the center line of the air outlet.

2. The small sleeve for the tuyeres of a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 1, characterized in that... The distance between the front welding port (9) and the oxygen nozzle port (3) is not less than 20mm, and the weld depth of the front welding port (9) is not less than 20mm.

3. The hydrogen-rich carbon-circulating oxygen blast furnace tuyeres sleeve according to claim 1, characterized in that, After welding is completed at the front welding port (9), a high-temperature and wear-resistant protective layer is added to the front welding port (9).

4. A method for controlling the small sleeve at the tuyere of a hydrogen-rich carbon-circulating oxygen blast furnace, characterized in that, include: During normal operation, the oxygen flow rate at the oxygen nozzle (3) is controlled to be no less than 150 m / s, and the distance between the high-temperature zone at the front end of the air outlet body (4) and the front end face (8) of the air outlet is no less than 200 mm.

5. The control method for the small sleeve at the tuyere of a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 4, characterized in that... During the initial startup or low-load operation, when the oxygen flow rate is lower than the preset normal value, control the number of oxygen inlets (2) to maintain the oxygen flow rate in the oxygen inlets (2) at no less than 150 m / s, and introduce 100-300 ml of oxygen into the oxygen inlets (2). Nitrogen gas.

6. The control method for the small sleeve of the tuyere in a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 4, characterized in that, Before oxygen is supplied to the hydrogen-rich carbon-circulating oxygen blast furnace, the heating gas or nitrogen in the high-temperature gas channel (5) is adjusted to more than 40% of the total air volume, and the airflow velocity in the high-temperature gas channel (5) is not less than 150m / s.

7. The control method for the small sleeve at the tuyere of a hydrogen-rich carbon-circulating oxygen blast furnace according to claim 6, characterized in that, Before supplying oxygen to the hydrogen-rich carbon-circulating oxygen blast furnace, an oxygen flow of not less than 500 ppm is first introduced into the oxygen channel (1). Nitrogen gas is added to the oxygen channel (1), and oxygen is added to the oxygen channel (1) while maintaining the oxygen flow rate in the oxygen channel (1) at no less than 150 m / s. When the oxygen in the oxygen channel (1) increases to more than 70% of the set oxygen amount, the nitrogen gas in the oxygen channel (1) is gradually withdrawn. Throughout the process, the flow rate in the oxygen channel (1) is maintained at no less than 150 m / s.

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