Pulverized coal feeding device for iron-making blast furnace

Abstract

The utility model discloses a pulverized coal feeding device for an iron-making blast furnace. The pulverized coal feeding device comprises a pulverized coal bin, an injection tank, a nitrogen gas source, a steam generator, a compressed air generator, a heat tracing pipe sleeve and a gas supplementing device. A discharge port of the pulverized coal bunker is communicated with a feed port of the injection tank through a blanking pipe; the nitrogen gas source is communicated with the pulverized coal bunker and the injection tank through pipelines, and a heat tracing pipe is arranged on the communication pipeline. By adopting the device, the temperature of pulverized coal entering the blast furnace can be effectively maintained, condensate water formed by condensation in the conveying process is reduced, the injection fluidity of blast furnace feeding is ensured, the temperature stability of the blast furnace is improved, and fluctuation is reduced.

Description

Technical Field

[0001] This application relates to the field of ironmaking production technology, and in particular to a pulverized coal feeding device for ironmaking blast furnaces. Background Technology

[0002] The heat required for ironmaking is mainly provided by the blast furnace, which is fueled by pulverized coal. After grinding, the pulverized coal is transported into the blast furnace by compressed air and burned to generate heat for ironmaking. The existing pulverized coal injection workshop integrates pulverized coal grinding, transportation, and injection. The continuous stability of the pulverized coal entering the blast furnace is related to the stability of the blast furnace temperature, which in turn affects the quality stability of the produced steel.

[0003] However, the existing pulverized coal injection plant has the following problems:

[0004] The temperature of the finished pulverized coal injected into the blast furnace in the existing pulverized coal injection workshop needs to be maintained at around 70℃. During the charging process and when the injection tank is pressurized with nitrogen (around 20℃), the temperature of the pulverized coal drops by about 15℃. Then, during the transportation process with compressed air at around 20℃ (the temperature of compressed air is even lower in spring, autumn and winter), the compressed air contains a large amount of condensate. As a result, the temperature of the pulverized coal delivered to the blast furnace tuyeres by the existing pneumatic conveying system is only 30-40℃. After absorbing moisture at this temperature, the pulverized coal has poor fluidity and high transportation resistance, making injection difficult. The low temperature of the pulverized coal entering the blast furnace tuyeres increases the amount of heat that needs to be absorbed, and the heat required for conversion into heat after combustion increases, increasing the difficulty of controlling the temperature stability of the blast furnace.

[0005] The existing equipment causes intermittent and unstable pulverized coal injection, which greatly restricts the normal injection of pulverized coal, causes frequent fluctuations in blast furnace temperature, and leads to abnormal furnace conditions, affecting the overall stability of blast furnace ironmaking production quality.

[0006] The information disclosed in the background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Utility Model Content

[0007] This application addresses the aforementioned technical problems by providing a pulverized coal feeding device for ironmaking blast furnaces, which achieves uniform and stable pulverized coal injection, stable and smooth blast furnace operation, continuous, uniform and stable pulverized coal injection, and stable blast furnace temperature with minimal fluctuations, thereby achieving stable production and improving productivity.

[0008] This application provides a pulverized coal feeding device for ironmaking blast furnaces, including: a pulverized coal silo, a pulverized coal injection tank, a nitrogen gas source, a steam generator, a compressed air generator, a heat tracing pipe sleeve, and a gas make-up device;

[0009] The discharge port of the pulverized coal silo and the inlet of the injection tank are connected by a discharge pipe; the nitrogen source is connected to the pipelines of the pulverized coal silo and the injection tank, and a heat tracing sleeve is installed on the connecting pipeline;

[0010] The compressed air generator and the air replenisher are connected by a heating sleeve installed on the connecting pipeline.

[0011] The steam generator is connected to the air inlet pipe of the heat exchange jacket of the heat tracing pipe sleeve.

[0012] Preferably, it includes: a main pipe, a pressurizing and replenishing gas inlet, and a fluidizing gas pipe at the bottom of the silo; one end of the main pipe is connected to a nitrogen gas source, and the other end is connected to one end of the pressurizing and replenishing gas inlet and the fluidizing gas pipe at the bottom of the silo; the extension end of the fluidizing gas pipe at the bottom of the silo is connected to the bottom of the pulverized coal silo; the extension end of the pressurizing and replenishing gas inlet is connected to the top of the injection tank.

[0013] Preferably, it includes: a second branch pipe and a third branch pipe; one end of the second branch pipe is connected to the main pipe and the other end is connected to the fluidizing gas inlet of the injection tank; one end of the third branch pipe is connected to the main pipe and the other end is connected to the boiling gas inlet of the injection tank.

[0014] Preferably, the heat tracing sleeve includes: a heat exchange jacket, an air inlet, an air outlet, and a vent pipe; the outer wall of the vent pipe is covered with the heat exchange jacket; the outer wall of the heat exchange jacket is provided with an air inlet and an air outlet at intervals; the air inlet is connected to the steam generator.

[0015] Preferably, it includes: a coal feeding valve; the coal feeding valve is installed on the pipeline connecting the injection tank and the air replenisher.

[0016] Preferably, it includes: pressure gauges; the pressure gauges are respectively installed on the pulverized coal silo and the injection tank.

[0017] Preferably, it includes: multiple valves; the valves are installed on the main pipe, the pressurizing and replenishing gas inlet, the fluidizing gas pipe at the bottom of the silo, and the discharge pipe.

[0018] Preferably, a pressurizing gas inlet is provided on the top surface of the injection tank; a fluidizing gas inlet is provided on the side wall of the injection tank; and a boiling gas inlet is provided on the bottom surface of the injection tank.

[0019] The beneficial effects that this application can produce include:

[0020] 1) The pulverized coal feeding device for blast furnaces provided in this application can effectively maintain the temperature of pulverized coal entering the blast furnace, reduce the condensate formed during the transportation process, ensure the flowability of the blast furnace feed, improve the temperature stability of the blast furnace, and reduce fluctuations. Attached Figure Description

[0021] Figure 1 A schematic diagram of a pulverized coal feeding device for an ironmaking blast furnace in at least one embodiment provided in this application;

[0022] Figure 2 A cross-sectional schematic diagram of the heat tracing pipe sleeve used in at least one embodiment provided in this application;

[0023] Figure 3 A schematic diagram of the pulverized coal injection feeding process for a blast furnace in at least one embodiment provided in this application.

[0024] Legend:

[0025] 1. Heat tracing pipe sleeve, 11. Heat exchange jacket, 12. Air inlet, 13. Air outlet, 14. Ventilation pipe, 2. Pulverizing tank, 21. Feed pipe, 22. Fluidizing gas inlet, 23. Boiling gas inlet, 24. Pressurizing and replenishing gas inlet, 321. Pressure gauge, 321. Pulverized coal bin, 31. Bottom fluidizing gas pipe, 32. Pressurizing and replenishing pipe, 4. Coal discharge valve, 5. Air replenisher. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0029] See Figures 1-3 The pulverized coal feeding device for blast furnace ironmaking provided in this application includes: a heat tracing pipe sleeve 1, a jet tank 2, a feeding pipe 21, a fluidizing gas inlet 22, a boiling gas inlet 23, a pressurizing and replenishing gas inlet 24, a pulverized coal silo 3, a fluidizing gas pipe at the bottom of the silo 31, and a pressurizing and replenishing pipe 32.

[0030] The nitrogen gas source is connected to the bottom air inlet pipe of the pulverized coal silo 3; a heat tracing sleeve 1 is installed on the pipeline connecting the nitrogen gas source and the pulverized coal silo 3; the heat tracing sleeve 1 includes a heat exchange jacket 11; both ends of the heat exchange jacket 11 are connected to the steam generator pipeline, and the steam generator can be a boiler or other device that can generate high-temperature gas; the generated steam is introduced into the heat exchange jacket 11 of the heat tracing sleeve 1 to heat the nitrogen passage pipe wrapped by the heat exchange jacket 11, thereby increasing the temperature of the carrier gas entering the pulverized coal silo 3, effectively ensuring the temperature of the pulverized coal after fluidization, and avoiding the condensation of gas caused by the pulverized coal temperature being too low.

[0031] The pulverized coal silo 3 and the injection tank 2 are connected by a feed pipe 21. The pulverized coal, after being gasified by nitrogen carrier gas, is fed into the injection tank 2 through the feed pipe 21. After being buffered in the injection tank 2, the pulverized coal enters the discharge pipe through a pipeline. The discharge pipe is connected to the inlet pipeline of the furnace front distributor. Coal discharge valves 4 and gas replenishers 5 are installed at intervals on the discharge pipe.

[0032] The outlet of the compressed air generator is connected to the inlet pipe of the make-up air device 5. A heat tracing sleeve 1 is installed on the connecting pipe between the compressed air generator and the make-up air device 5. This heat tracing sleeve 1 also has a heat exchange jacket 11, and a tube is installed inside the heat exchange jacket 11. The tube is attached to the pipe to heat the compressed air flowing inside the tube, thereby reheating the discharged pulverized coal at the make-up air device 5. This avoids the pulverized coal from cooling down due to residence time in the injection tank 2, dries the condensate contained in the pulverized coal, reduces condensate, improves the flowability of the pulverized coal entering the furnace front distributor, improves the flow stability and temperature of the pulverized coal entering the blast furnace, and maintains a stable blast furnace temperature. The compressed air generator is a commercially available device and will not be described in detail here.

[0033] In one specific embodiment, a feed inlet is provided at the top of the pulverized coal silo 3, through which pulverized coal is fed.

[0034] In one specific embodiment, the nitrogen source can be a commonly used nitrogen source such as a nitrogen storage tank. For example, when it is a nitrogen storage tank, the outlet of the storage tank is provided with a main pipe, and the extension end of the main pipe is connected to one end of the fluidizing gas pipe 31 at the bottom of the tank and the pressurization and pressure replenishment pipe 32, respectively.

[0035] In one specific embodiment, the extension end of the fluidizing gas pipe 31 at the bottom of the silo is connected to the fluidizing gas port at the bottom of the pulverized coal silo 3.

[0036] In one specific embodiment, it includes: multiple valves; valves are respectively installed on the fluidizing gas pipe 31 at the bottom of the silo and the pressurization and replenishment pipe 32.

[0037] In one specific embodiment, the extension end of the pressurizing and replenishing pipe 32 is connected to the pressurizing and replenishing air inlet 24 at the top of the injection tank 2 to achieve pressurization or pressure adjustment of the injection tank 2.

[0038] In one specific embodiment, the system includes: multiple pressure gauges 321; the pressure gauges 321 are installed on the pulverized coal silo 3 and the injection tank 2. This allows operators to monitor the pressure changes inside the pulverized coal silo 3 and the injection tank 2 in real time.

[0039] In one specific embodiment, it includes: a coal feeding valve 4; the coal feeding valve 4 is disposed on the discharge pipe and disposed between the air replenisher 5 and the injection tank 2.

[0040] In one specific embodiment, the system includes a second branch pipe and a third branch pipe. One end of the second branch pipe is connected to the main pipe, and the other end is connected to the fluidizing gas inlet 22 on the side wall of the injection tank 2. One end of the third branch pipe is connected to the main pipe, and the other end is connected to the boiling gas inlet 23 at the bottom of the injection tank 2. Heated nitrogen is used to promote the fluidization of pulverized coal in the injection tank 2, facilitating transportation. By opening the fluidizing gas inlet 22 and the boiling gas inlet 23 on the side wall and bottom of the injection tank 2 respectively, carrier gas is introduced into the injection tank 2 from multiple angles, promoting the fluidization of pulverized coal in the injection tank 2. At the same time, it increases the contact with the heated carrier gas, thereby increasing the temperature of the pulverized coal, reducing condensate in the pulverized coal, and improving the flow stability of the pulverized coal.

[0041] In one specific embodiment, the heat tracing sleeve 1 includes: a heat exchange jacket 11, an air inlet 12, an air outlet 13, and a vent pipe 14; the air inlet 12 and the air outlet 13 are disposed opposite each other on the outer wall of the heat exchange jacket 11; the air inlet 12 is connected to the steam generator pipeline; the heat exchange jacket 11 covers the outer wall of the vent pipe 14 and makes heat exchange contact with the vent pipe 14. The steam introduced into the heat exchange jacket 11 can heat the airflow in the vent pipe 14, thereby achieving the effect of heating the carrier gas.

[0042] In use, nitrogen, as the carrier gas, is heated by the heat tracing pipe sleeve 1 and then enters the injection tank 2 and the pulverized coal bin 3. In the injection tank 2, it plays a role in fluidizing the pulverized coal at the bottom of the bin. The nitrogen carrier gas is introduced into the injection tank 2 from multiple angles through the pressurizing and replenishing gas inlet 24, the second branch pipe, and the third branch pipe, respectively, and plays a role in pressurizing, replenishing pressure, fluidizing, and boiling. It fully contacts the pulverized coal, increases the temperature of the pulverized coal, and reduces the condensate contained in the pulverized coal, which helps to maintain the fluidity of the pulverized coal.

[0043] The fluidized coal powder moves from the injection tank 2 to the furnace front distributor. At this time, the coal powder is reheated by the heated compressed air in the make-up air device 5, which dries the condensate formed from the injection tank 2 to the make-up air device 5, maintains the coal powder temperature, maintains the quality of the coal powder entering the blast furnace, and thus ensures the stability of the blast furnace temperature.

[0044] The air supply device 5 can be a tank with pulverized coal inlet and outlet on both sides and an air supply port at the bottom. A pressure gauge is also installed to monitor pressure changes. The tank size can be selected and adjusted according to the pulverized coal feed rate.

[0045] Implementation results:

[0046] The above equipment has been put into use in production, and the project has been completed and put into use. The temperature of the pulverized coal entering the blast furnace can be stably controlled at around 70℃, which effectively prevents the pulverized coal from being moist, adsorbing, agglomerating, and sticking, and improves the flow rate of pulverized coal in the pipeline to prevent lance blockage, thus creating favorable conditions for full-load dense phase injection of the blast furnace.

[0047] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pulverized coal feeding device for an ironmaking blast furnace, characterized in that, include: Pulverized coal silo (3), injection tank (2), nitrogen source, steam generator, compressed air generator, heat tracing pipe sleeve (1), air replenisher (5); The outlet of the pulverized coal silo (3) and the inlet of the injection tank (2) are connected by a feed pipe (21); the nitrogen gas source is connected to the pipelines of the pulverized coal silo (3) and the injection tank (2), and a heat tracing sleeve (1) is installed on the connecting pipeline; The compressed air generator and the air replenisher (5) are connected by a pipeline, and a heat tracing sleeve (1) is installed on the connecting pipeline; The steam generator is connected to the air inlet pipe of the heat exchange jacket (11) of the heat tracing sleeve (1).

2. The pulverized coal feeding device for blast furnaces according to claim 1, characterized in that, include: The main pipe, the pressurizing and replenishing gas inlet (24), and the fluidizing gas pipe at the bottom of the silo (31) are connected. One end of the main pipe is connected to the nitrogen gas source, and the other end is connected to one end of the pressurizing and replenishing gas inlet (24) and the fluidizing gas pipe at the bottom of the silo (31). The extension end of the fluidizing gas pipe at the bottom of the silo (31) is connected to the bottom of the pulverized coal silo (3). The extension end of the pressurizing and replenishing gas inlet (24) is connected to the top of the injection tank (2).

3. The pulverized coal feeding device for blast furnaces according to claim 2, characterized in that, include: Second branch pipe and third branch pipe; one end of the second branch pipe is connected to the main pipe and the other end is connected to the fluidizing gas inlet (22) of the injection tank (2); one end of the third branch pipe is connected to the main pipe and the other end is connected to the boiling gas inlet (23) of the injection tank (2).

4. The pulverized coal feeding device for blast furnaces according to claim 1, characterized in that, The heat tracing sleeve (1) includes: a heat exchange jacket (11), an air inlet (12), an air outlet (13), and a vent pipe (14); the outer wall of the vent pipe (14) is covered with the heat exchange jacket (11); the outer wall of the heat exchange jacket (11) is provided with an air inlet (12) and an air outlet (13) at intervals; the air inlet (12) is connected to the steam generator.

5. The pulverized coal feeding device for blast furnaces according to claim 1, characterized in that, include: Coal discharge valve (4); The coal discharge valve (4) is installed on the pipeline connecting the injection tank (2) and the air replenisher (5).

6. The pulverized coal feeding device for blast furnaces according to claim 1, characterized in that, include: Pressure gauge (321); Pressure gauge (321) is installed on the pulverized coal silo (3) and the injection tank (2).

7. The pulverized coal feeding device for blast furnaces according to claim 2, characterized in that, include: Multiple valves are installed on the main pipe, the pressurization and replenishment gas inlet (24), the fluidizing gas pipe at the bottom of the silo (31), and the discharge pipe (21).

8. The pulverized coal feeding device for blast furnaces according to claim 1, characterized in that, A pressurizing gas inlet (24) is provided on the top surface of the injection tank (2); a fluidizing gas inlet (22) is provided on the side wall of the injection tank (2); and a boiling gas inlet (23) is provided on the bottom surface of the injection tank (2).

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