Long-life blast furnace coal injection gun with anti-blocking and method thereof

Abstract

The application discloses a long-service-life blast furnace coal injection gun capable of preventing blockage and belongs to the technical field of steel metallurgy. The long-service-life blast furnace coal injection gun comprises a straight blow pipe and a gun body, the gun body is divided into a low-temperature section and a high-temperature section, a three-way quick connector is arranged between the low-temperature section and the high-temperature section, the three-way quick connector is used for connecting the low-temperature section and the high-temperature section, the two ends of the three-way quick connector are connected with the low-temperature section and the high-temperature section respectively, and the high-temperature section is inserted into the interior of the straight blow pipe. The long-service-life blast furnace coal injection gun solves the problems of short service life and easy blockage of the existing blast furnace coal injection gun. The low-temperature section and the high-temperature section are connected through the three-way quick connector, high-pressure N2 gas can be introduced to clean the blockage in sections, the low-temperature section is made of common wear-resistant steel, the high-temperature section is made of high-temperature-resistant steel in the shape of a gradually expanding horn, the interior of the pipe is sprayed with wear-resistant material and is designed in a small arc shape, and the service life can be effectively prolonged through the above design.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel metallurgy, in particular to a long-life blast furnace coal injection gun and method. BACKGROUND

[0002] Blast furnace coal injection is to inject finely ground coal into the blast furnace from the tuyere to replace coke to provide heat and reducing agent, thereby reducing coke ratio and pig iron cost. It is a major technical revolution in modern blast furnace smelting and a key technology for blast furnaces to compete with other ironmaking methods and continue to survive and develop. Therefore, blast furnace coal injection has been widely used worldwide. The coal injection gun is one of the important equipment of the blast furnace coal injection system, which is made of heat-resistant seamless steel pipe and divided into ordinary type and oxygen coal gun according to the different injection media. The ordinary type coal injection gun is divided into inclined insertion type, straight insertion type and tuyere fixed type according to the insertion mode, and the inclined insertion type coal injection gun is widely used for blast furnace coal injection.

[0003] The Chinese patent with publication number CN104611489A discloses a blast furnace coal injection gun and a manufacturing method thereof, which comprises a gun seat, an intermediate pipe, a connecting piece and a gun head. One end of the intermediate pipe is inserted into the gun seat, and the other end of the intermediate pipe is connected to the gun head through the connecting piece. The intermediate pipe and the connecting piece are connected through a first thread, and the gun head and the connecting piece are connected through a second thread. The middle part of the first thread and the second thread has a rubber gasket. The patent can effectively recycle the gun that is burned by high temperature in the front section, and only the gun head is burned by high temperature after using the invention, so that the gun head can be replaced, which has certain economic value.

[0004] The above-mentioned patent still has the following problems in actual use:

[0005] 1. During normal smelting of the blast furnace, the coal injection is injected into the blast furnace through the coal injection gun, which may cause different degrees of pipe blockage of the coal injection gun due to the influence of the temperature, humidity, flow rate, quality and impurities in the coal powder;

[0006] 2. The coal flow wears the tuyere and the gun has a short service life, the temperature rising speed, volatile decomposition and combustion speed of the coal powder at the tuyere are small;

[0007] Therefore, the existing needs are not met, and therefore we propose a long-life blast furnace coal injection gun and method. SUMMARY

[0008] The present application aims to provide a long-life blast furnace coal injection gun and method for preventing blockage, which connects a low-temperature section of the injection gun and a high-temperature section of the injection gun through a three-way quick connector, and can clean the blockage of the injection gun in sections by passing high-pressure N2 gas, and which is convenient for clamping, quickly cleaning blockage, sealing the body of the injection gun and preventing the injection gun from shaking, thereby solving the problems in the above background art.

[0009] To achieve the above object, the present application provides the following technical solution: a long-life blast furnace coal injection gun for preventing blockage, comprising a straight blow pipe and an injection gun, the body of the injection gun is divided into a low-temperature section and a high-temperature section, a three-way quick connector is arranged between the low-temperature section and the high-temperature section, the three-way quick connector is used for connecting the low-temperature section and the high-temperature section, the two ends of the three-way quick connector are connected with the low-temperature section and the high-temperature section respectively, and the high-temperature section is inserted into the inside of the straight blow pipe.

[0010] Further, the part of the injection gun entering the inside of the straight blow pipe is filled with refractory cotton, and a sealing device for preventing air leakage is arranged on one side of the injection gun.

[0011] Further, the low-temperature section of the injection gun is made of ordinary wear-resistant steel, the high-temperature section of the injection gun is made of large-diameter horn-shaped high-temperature-resistant steel, the inside of the pipeline of the high-temperature section is sprayed with wear-resistant material and designed in a small arc shape, and the included angle between the high-temperature section and the center line of the tuyere is 3°-5°.

[0012] Further, the outer side of the pipe wall of the high-temperature section of the injection gun is provided with a buckle, the three-way quick connector is designed in a 180° opposite double clamping groove, the clamping groove of the three-way quick connector corresponds to the buckle on the outer side of the pipe wall of the high-temperature section, the buckle is inserted into the clamping groove, and the high-temperature section and the three-way quick connector are connected in a clamping manner.

[0013] Further, the inside of the three-way quick connector is provided with a high-temperature-resistant sealing gasket for sealing between the high-temperature section.

[0014] An implementation method of a long-life blast furnace coal injection gun for preventing blockage, comprising the following steps:

[0015] S1: the low-temperature section of the injection gun is made of ordinary wear-resistant steel, the high-temperature section of the injection gun is made of large-diameter horn-shaped high-temperature-resistant steel, the inside of the pipeline of the high-temperature section is sprayed with wear-resistant material and designed in a small arc shape, the low-temperature section and the high-temperature section of the injection gun are connected through a three-way quick connector, and the low-temperature section and the high-temperature section and the three-way quick connector are connected in a clamping manner, the three-way quick connector passes high-pressure N2 gas through a quick connector valve, and the high-pressure N2 gas is used for cleaning blockage in sections;

[0016] S2: if the high temperature section of the lance is blocked, first close the blast furnace coal injection lance and the injection branch pipe valve, connect the high pressure N2 gas in the three-way quick connector quick joint valve to the high temperature section of the lance, and use the high pressure N2 gas to spray the blockage in the high temperature section of the lance into the blast furnace;

[0017] S3: if the low temperature section of the lance is blocked, first close the blast furnace coal injection lance and the injection branch pipe valve, connect the high pressure N2 gas to the high temperature section of the lance, and use the high pressure N2 gas to blow back and clean the blockage in the low temperature section of the lance.

[0018] Compared with the prior art, the beneficial effects of the present application are:

[0019] 1. The low temperature section and the high temperature section of the lance are connected by a three-way quick connector, high pressure N2 gas can be introduced through the three-way quick connector, the low temperature section and the high temperature section of the lance can be cleaned and blocked in sections by high pressure N2 gas, the three-way quick connector is designed with a 180° object double clamping groove, and a high temperature resistant sealing gasket is arranged in the three-way quick connector, so that the three-way quick connector is convenient to clamp and quickly clean and block, and the lance barrel is sealed and prevented from shaking.

[0020] 2. According to the present application, the lance barrel is divided into a low temperature section and a high temperature section before and after entering the tuyere, the low temperature section is made of ordinary wear-resistant steel, the high temperature section pipe is gradually expanded and shaped and made of high temperature resistant steel, and the inside of the high temperature section pipe is sprayed with wear-resistant material and designed with a small arc, which can effectively prolong the service life. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a schematic diagram of the lance into the straight blowing pipe of the present application;

[0022] Figure 2 It is a schematic diagram of the lance structure and the three-way quick connector of the present application;

[0023] Figure 3 It is a schematic diagram of the three-way quick connector structure of the present application.

[0024] In the figure: 1, straight blowing pipe; 2, lance; 3, low temperature section of the lance; 4, three-way quick connector; 5, high temperature section of the lance. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] In order to solve the technical problem that the blast furnace coal injection gun may be blocked to different degrees in the process of injecting coal powder into the blast furnace through the blast furnace coal injection gun, which is affected by the temperature, humidity, flow rate, quality and impurities in the coal powder, please refer to Figures 1-3 The embodiment provides the following technical scheme:

[0027] A long-life blast furnace coal injection gun capable of preventing blockage comprises a straight blow pipe 1 and a lance 2, and the part of the lance 2 entering the interior of the straight blow pipe 1 is filled with refractory cotton. The refractory cotton can improve the high-temperature resistance of the part of the lance 2 entering the interior of the straight blow pipe 1, and a sealing device is arranged on one side of the lance 2 to prevent air leakage, thereby improving the sealing performance of the lance 2 and preventing the lance 2 from vibrating. The lance 2 is divided into a low-temperature section 3 and a high-temperature section 5. The inner diameters of the high-temperature section 5 and the low-temperature section 3 are both 18 mm, and the diameter of the nozzle of the lance 2 is 24-26 mm. This design can slow down the flow rate of the coal powder and increase the preheating time. A three-way quick connector 4 is arranged between the low-temperature section 3 and the high-temperature section 5. The three-way quick connector 4 is used to connect the low-temperature section 3 and the high-temperature section 5. The two ends of the three-way quick connector 4 are connected to the low-temperature section 3 and the high-temperature section 5, respectively. The high-temperature section 5 is inserted into the interior of the straight blow pipe 1.

[0028] A buckle is arranged on the outer side of the pipe wall of the high-temperature section 5. The three-way quick connector 4 adopts a 180° opposite double-slot design. The double slots of the three-way quick connector 4 correspond to the buckles on the outer side of the pipe wall of the high-temperature section 5. The connection can be completed by inserting the buckles into the double slots and rotating 180°. The high-temperature section 5 is connected to the three-way quick connector 4 through clamping. A high-temperature sealing gasket is arranged in the three-way quick connector 4 to seal the high-temperature section 5. The high-temperature sealing gasket has the characteristics of sealing and high-temperature resistance.

[0029] Specifically, the low-temperature section 3 and the high-temperature section 5 of the lance are connected by the three-way quick connector 4, and the three-way quick connector 4 is used to introduce high-pressure N2 gas to clean the blockage, when the high-temperature section 5 of the lance is blocked, first, the blast furnace coal injection lance and the injection branch valve are closed, then the three-way quick connector 4 is connected to the high-pressure N2 gas through the quick valve, the high-pressure N2 gas introduced by the quick valve is connected to the position of the high-temperature section 5 of the lance, so that the blockage of the high-temperature section 5 of the lance can be blown into the blast furnace by the introduced high-pressure N2 gas, when the low-temperature section 3 of the lance is blocked, first, the blast furnace coal injection lance and the injection branch valve are also closed, then the high-pressure N2 gas is introduced to the position connected to the high-temperature section 5 of the lance, and the high-pressure N2 gas is used to blow back to clean the blockage of the low-temperature section 3 of the lance, the setting of the lance 2 can reduce the blockage of the blast furnace coal injection lance caused by the large particles of the transported agglomerate, so that the blast furnace coal injection can be improved, and the wear of the tuyere small sleeve caused by the pulverized coal can be reduced, meanwhile, the three-way quick connector 4 is designed with a 180° opposite double clamping groove, which is convenient for clamping the three-way quick connector 4 with the low-temperature section 3 and the high-temperature section 5 of the lance, so that the disassembly is more convenient, thereby the blockage can be quickly cleaned, the high-temperature sealing gasket arranged in the three-way quick connector 4 plays a sealing role, which can ensure the sealing of the lance 2, and prevent the lance 2 from shaking.

[0030] To solve the technical problem of short service life in the prior art, please refer to Figures 1-2 The embodiment provides the following technical scheme:

[0031] The low-temperature section 3 of the lance is made of ordinary wear-resistant steel, the high-temperature section 5 of the lance is made of large-diameter horn-shaped high-temperature-resistant steel, the inside of the pipeline of the high-temperature section 5 of the lance is sprayed with wear-resistant material and is designed in a small arc shape, the tuyere end of the straight blowing pipe 1 is provided with a large, medium and small sleeve, and the included angle between the high-temperature section 5 of the lance and the center line of the tuyere is 3°-5°, which can reduce the wear of the tuyere small sleeve caused by the pulverized coal flow under the action of high-speed hot air, thereby prolonging the service life of the tuyere small sleeve.

[0032] Specifically, the lance 2 is divided into a low-temperature section 3 and a high-temperature section 5 before and after entering the tuyere, the low-temperature section 3 is made of ordinary wear-resistant steel material, the pipeline of the high-temperature section 5 is gradually expanded in a horn shape and is made of high-temperature-resistant steel material, the inside of the pipeline of the high-temperature section 5 is sprayed with wear-resistant material and is designed in a small arc shape, so that the inside of the pipeline of the high-temperature section 5 has wear resistance, thereby avoiding the wear of the inside of the pipeline of the high-temperature section 5 caused by the pulverized coal, and through the above design, the service life of the lance 2 can be effectively improved.

[0033] In the embodiment, a 2500m 3 The comparison results before and after the blast furnace uses the present application are shown in Table 1.

[0034] Coal ratio Coke ratio Yield Small set life Lance life Lance cost Liquid iron > 1500 Liquid iron cost kg / t kg / t t / d Days Days Yuan / branch Tank car times Yuan / ton Before transformation 151 315 6975 218 88 125 18 3206 After transformation 157 309 7025 240 111 110 22 3198

[0035] Table 1

[0036] From Table 1, it can be seen that the coal ratio of a 2500m 3 The coal ratio of the blast furnace is 151kg / t before use, the coke ratio is 315kg / t, the coal ratio is 157kg / t after use, the coke ratio is 309kg / t, the average service life of the 30 small sleeves is increased from 218 days to 240 days, and the molten iron cost is reduced by 8 yuan / ton.

[0037] Implementation effect:

[0038] A 2500m 3 The effects of the blast furnace after implementing the technology of the application are as follows:

[0039] 1) Reducing the large particle injection material caused by transportation aggregation to block the blast furnace coal injection gun, and increasing the blast furnace coal injection ratio by 3%;

[0040] 2) Reducing the wear of the small sleeve caused by coal powder, and increasing the average service life of the blast furnace tuyere small sleeve by 10%;

[0041] 3) Reasonably distributing the heat of the blast furnace, reducing the molten iron temperature deviation between the tanks from 12℃ to 8℃, and increasing the number of times of the molten iron temperature being above 1500℃ per day by 18%;

[0042] 4) Reducing the cost of the injection gun 2 by more than 10%, and increasing the service life of the injection gun 2 by more than 30%.

[0043] Specifically, the embodiment also proposes an implementation method of the anti-blocking long-life blast furnace coal injection gun, which comprises the following steps:

[0044] S1: The injection gun low temperature section 3 is made of ordinary wear-resistant steel, the injection gun high temperature section 5 is made of large-diameter horn-shaped high-temperature-resistant steel, the inside of the pipeline of the injection gun high temperature section 5 is sprayed with wear-resistant material and adopts a small arc design, the injection gun low temperature section 3 and the injection gun high temperature section 5 are connected by a three-way quick connector 4, and the injection gun low temperature section 3 and the injection gun high temperature section 5 are connected with the three-way quick connector 4 by clamping connection, the three-way quick connector 4 is connected with high-pressure N2 gas through a quick valve, and the high-pressure N2 gas is used for segmented blockage cleaning;

[0045] S2: If the injection gun high temperature section 5 is blocked, first close the blast furnace coal injection gun and the injection blowing branch valve, connect the high-pressure N2 gas in the three-way quick connector 4 quick valve with the injection gun high temperature section 5 position, and use the high-pressure N2 gas to spray the blockage in the injection gun high temperature section 5 into the blast furnace;

[0046] S3: If the injection gun low temperature section 3 is blocked, first close the blast furnace coal injection gun and the injection blowing branch valve, connect the high-pressure N2 gas with the injection gun high temperature section 5 connection position, and use the high-pressure N2 gas to blow back, and clean the blockage of the injection gun low temperature section 3 by the back blowing of the high-pressure N2 gas.

[0047] Working principle: the low-temperature section 3 and the high-temperature section 5 of the lance are connected by the three-way quick connector 4, the three-way quick connector 4 can pass in high-pressure N2 gas, the high-pressure N2 gas can be used to blow the blockage in the low-temperature section 3 and the high-temperature section 5 of the lance, thereby the lance 2 can be segmented to clean the blockage, the setting of the lance 2 can reduce the blockage of the blast furnace coal injection lance caused by the large particles of the transported agglomerates, thereby the blast furnace coal injection ratio can be improved and the wear of the small sleeve caused by the pulverized coal can be reduced, at the same time, the three-way quick connector 4 adopts the 180° opposite double clamping groove design, which is convenient for the clamping between the three-way quick connector 4 and the low-temperature section 3 and the high-temperature section 5 of the lance, so that the disassembly is more convenient, and the high-temperature sealing gasket arranged in the three-way quick connector 4 plays a sealing role, which can ensure the sealing of the lance 2, prevent the lance 2 from shaking, the low-temperature section 3 of the lance is made of ordinary wear-resistant steel material, the pipeline of the high-temperature section 5 of the lance is gradually expanded and is made of high-temperature resistant steel material, the inside of the pipeline of the high-temperature section 5 of the lance is sprayed with wear-resistant material and adopts a small arc design, through the above design, the service life of the lance 2 can be effectively improved.

[0048] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0049] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A blast furnace coal injection gun with anti-clogging and long service life, comprising a straight blowing pipe (1) and a gun (2), characterized in that: The gun body of the spray gun (2) is divided into a spray gun low-temperature section (3) and a spray gun high-temperature section (5), and a three-way quick-connect joint (4) is provided between the spray gun low-temperature section (3) and the spray gun high-temperature section (5). The three-way quick-connect joint (4) is used to connect the spray gun low-temperature section (3) and the spray gun high-temperature section (5). The two ends of the three-way quick-connect joint (4) are respectively connected to the spray gun low-temperature section (3) and the spray gun high-temperature section (5), and the spray gun high-temperature section (5) is inserted into the interior of the straight blowing pipe (1); The low-temperature section (3) of the spray gun is made of ordinary wear-resistant steel, and the high-temperature section (5) of the spray gun is made of large-caliber trumpet-shaped high-temperature resistant steel. The interior of the pipe of the high-temperature section (5) of the spray gun is sprayed with wear-resistant material and adopts a small arc design. The angle between the high-temperature section (5) of the spray gun and the center line of the tuyere is 3°-5°; The outer side of the pipe wall of the high-temperature section (5) of the spray gun is provided with a snap fastener. The three-way quick-connect joint (4) adopts a 180° opposite double-slot design. The slot of the three-way quick-connect joint (4) corresponds to the snap fastener on the outer side of the pipe wall of the high-temperature section (5) of the spray gun. The high-temperature section (5) of the spray gun is snap-connected to the three-way quick-connect joint (4) by inserting the snap fastener into the slot.

2. The anti-blocking and long-life blast furnace coal injection gun according to claim 1, characterized in that: The portion where the spray gun (2) enters the interior of the direct blowing pipe (1) is filled with refractory cotton, and a sealing device for preventing air leakage is provided on one side of the spray gun (2).

3. The anti-blocking and long-life blast furnace coal injection gun according to claim 1, characterized in that: The interior of the three-way quick-connect joint (4) is provided with a high-temperature resistant sealing gasket for sealing with the high-temperature section (5) of the spray gun.

4. A method for implementing the anti-blocking and long-life blast furnace coal injection lance according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: The low-temperature section (3) of the spray gun is made of ordinary wear-resistant steel, and the high-temperature section (5) of the spray gun is made of large-caliber trumpet-shaped high-temperature steel. The interior of the pipe of the high-temperature section (5) of the spray gun is sprayed with wear-resistant material and adopts a small arc design. The low-temperature section (3) of the spray gun and the high-temperature section (5) of the spray gun are connected by a three-way quick-connect joint (4). The low-temperature section (3) of the spray gun and the high-temperature section (5) of the spray gun are connected to the three-way quick-connect joint (4) by a card connection method. The three-way quick-connect joint (4) is fed with high-pressure N2 gas through a quick-connect valve, and the high-pressure N2 gas is used to perform blockage cleaning in sections; S2: If the high temperature section (5) of the blast furnace coal injection gun is blocked, first close the valve of the blast furnace coal injection gun and the injection branch pipe, connect the high pressure N2 gas introduced by the quick-connect valve of the three-way quick-connect joint (4) to the position of the high temperature section (5) of the blast furnace, and use the high pressure N2 gas to spray the blockage in the high temperature section (5) of the blast furnace into the interior of the blast furnace; S3: If the low-temperature section (3) of the spray gun is blocked, first close the blast furnace coal injection gun and the injection branch valve, use high-pressure N2 gas to connect the high-temperature section (5) of the spray gun, and backflush the high-pressure N2 gas to clear the blockage of the low-temperature section (3) of the spray gun through the backflush of high-pressure N2 gas.

Images