Pulverized coal injection system for blast furnace

Abstract

The utility model discloses a blast furnace pulverized coal injection system, which is characterized in that compressed air in a compressed air tank is conveyed to a heat exchanger through a pipeline to be heated, and the heated compressed air is conveyed along a pneumatic conveying pipeline to convey pulverized coal in a pulverized coal bin to a distributor; flue gas subjected to heat exchange with the heat exchanger is conveyed to a spiral heating pipe wound on the pneumatic conveying pipeline along an exhaust pipe to be heated, the heated flue gas is correspondingly conveyed to a distribution pipe connected to the upper portion of the distributor through a plurality of connecting branch pipes, and the distribution pipe is provided with a uniform pressure regulating system. The heated flue gas heats the pneumatic conveying pipeline through the spiral heating pipe to prevent the temperature of the pneumatic conveying pipeline from being lost in winter, so that the temperature of the pulverized coal entering the distributor is ensured; the distribution pipes of the distributor are regulated and controlled through the uniform pressure regulating system, so that the pressure balance of the multiple distribution pipes can be ensured, and the stability of pulverized coal entering the blast furnace is ensured.

Description

Technical Field

[0001] The utility model relates to the field of pulverized coal injection, in particular to a pulverized coal injection system for blast furnaces. Background Art

[0002] Coal injection is an important part of blast furnace ironmaking technology. By injecting pulverized coal into the tuyere area of the blast furnace, the efficiency of the reduction reaction of iron ore in the blast furnace is improved, the coke consumption in the blast furnace is reduced, the output of the blast furnace is increased, and the ironmaking cost is reduced.

[0003] In the existing pulverized coal injection system, the compressed air in the compressed air tank 1 is heated by passing through the heat exchanger 2, and the pulverized coal in the pulverized coal bin 4 is transported along the pneumatic conveying pipeline 3 to the distributor 5 by the heated compressed air. After being distributed by the distributor 5, the pulverized coal is transported along multiple distribution pipes 6 to the pulverized coal injection pipes of the blast furnace for feeding. Among them, the heat exchanger 2 can use the heated compressed air to heat the pulverized coal, reducing the energy consumption of the blast furnace. However, during the winter transportation, the temperature loss of the pneumatic conveying pipeline 3 is relatively large, reducing the temperature of the pulverized coal entering the blast furnace. Moreover, the pressures of the multiple distribution pipes 6 for distributing pulverized coal by the distributor 5 are also different, affecting the balance of the transportation of the distribution pipes 6. Summary of the Utility Model

[0004] In order to solve the above existing problems, the utility model provides a pulverized coal injection system for blast furnaces.

[0005] The utility model is realized by the following technical solutions:

[0006] A pulverized coal injection system for blast furnaces, in which the compressed air in the compressed air tank is transported through a pipeline to a heat exchanger for heating, and the heated compressed air transports the pulverized coal in the pulverized coal bin along the pneumatic conveying pipeline to the distributor. The flue gas after heat exchange with the heat exchanger is transported along the exhaust pipe to a spiral heating pipe wound around the pneumatic conveying pipeline for heating, and the heated flue gas is correspondingly transported to the distribution pipes connected to the upper part of the distributor through multiple connecting branch pipes. The distribution pipes are provided with a uniform pressure regulating system.

[0007] Further optionally, the uniform pressure regulating system includes a PLC controller, the PLC controller is electrically connected to a pressure detector installed on the corresponding distribution pipe, and the PLC controller is electrically connected to a pressurizing fan installed on the connecting branch pipe 0.

[0008] Further optionally, the shell side inlet of the heat exchanger is connected to an inlet pipe, and the shell side outlet of the heat exchanger is connected to an exhaust pipe.

[0009] Further optionally, the bottom of the pulverized coal bin is connected to the pneumatic conveying pipeline through a discharge pipe.

[0010] Further optionally, control valves are installed on the pneumatic conveying pipeline, the inlet pipe, the exhaust pipe and the discharge pipe.

[0011] Compared with the existing technology, the beneficial effects of the present utility model are as follows: By heating the compressed air for pneumatic conveying, the heated flue gas passes through the spiral heating pipe to heat the pneumatic conveying pipeline to prevent heat dissipation in winter, thereby ensuring the temperature of the pulverized coal entering the distributor; the distribution pipes of the distributor are regulated through a uniform pressure regulating system, which can ensure the pressure balance of multiple distribution pipes and the stability of the pulverized coal entering the blast furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the system of the present utility model;

[0013] Figure 2 is a schematic diagram of the prior art of the present utility model;

[0014] In the figure: compressed air tank 1, heat exchanger 2, pneumatic conveying pipeline 3, pulverized coal bin 4, distributor 5, distribution pipe 6, intake pipe 7, exhaust pipe 8, spiral heating pipe 9, connecting branch pipe 10, pressurizing fan 11, PLC controller 12, pressure detector 13, control valve 14. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The present utility model will be further described in detail below in conjunction with the drawings and specific embodiments:

[0016] As Figure 1 shown, a blast furnace pulverized coal injection system, the compressed air in the compressed air tank 1 is conveyed through a pipeline to the heat exchanger 2 for heating, and the heated compressed air is conveyed along the pneumatic conveying pipeline 3 to convey the pulverized coal in the pulverized coal bin 4 to the distributor 5. The flue gas after heat exchange with the heat exchanger 2 is conveyed along the exhaust pipe 8 to the spiral heating pipe 9 wound around the pneumatic conveying pipeline 3 for heating, and the heated flue gas is conveyed to the distribution pipe 6 connected to the upper part of the distributor 5 through a plurality of connecting branch pipes 10. The distribution pipe 6 is provided with a uniform pressure regulating system, and the pressure uniformity of each distribution pipe 6 is ensured through the uniform pressure regulating system.

[0017] The uniform pressure regulating system includes a PLC controller 12. The PLC controller 12 is electrically connected to the pressure detector 13 installed on the corresponding distribution pipe 6, and the PLC controller 12 is electrically connected to the pressurizing fan 11 installed on the connecting branch pipe 10. The rotation speed of the pressurizing fan 11 is controlled by the feedback of the pressure of the distribution pipe 6 to ensure the balanced stability of the pressure of the pulverized coal entering the blast furnace in each distribution pipe 6.

[0018] The shell side inlet of the heat exchanger 2 is connected to the intake pipe 7, and the shell side outlet of the heat exchanger 2 is connected to the exhaust pipe 8.

[0019] The bottom of the pulverized coal bin 4 is connected to the pneumatic conveying pipeline 3 through a discharge pipe. When the high-pressure gas in the pneumatic conveying pipeline 3 passes through the discharge pipe at the bottom of the pulverized coal bin 4, the siphon principle will be generated to adsorb and mix the pulverized coal in the discharge pipe, and finally realize the pneumatic conveying of the materials in the pulverized coal bin 4.

[0020] Control valves 14 are installed on the pneumatic conveying pipeline 3, the intake pipe 7, the exhaust pipe 8 and the discharge pipe.

[0021] The implementation principle of an embodiment of a pulverized coal injection system for a blast furnace in this application is as follows:

[0022] The compressed air in the compressed air tank 1 is heated by the heat exchanger 2 and transports the pulverized coal in the pulverized coal bin 4 along the pneumatic conveying pipeline 3 to the distributor 5. After being distributed by the distributor 5, it is transported to the blast pipe of the blast furnace along multiple distribution pipes 6;

[0023] The 170°C high-temperature flue gas in the intake pipe 7 enters the heat exchanger 2 for heat exchange. After heat exchange, the 100 - 105°C flue gas is transported along the exhaust pipe 8 to the spiral heating pipe 9 wound on the pneumatic conveying pipeline 3. The external of the pneumatic conveying pipeline 3 is heated through the spiral heating pipe 9 to prevent heat dissipation in winter, so as to ensure the temperature of the pulverized coal entering the distributor 5;

[0024] The flue gas passing through the spiral heating pipe 9 is transported through the connecting branch pipe 10 to the corresponding distribution pipe 6 for transportation. The pressure detector 13 of the corresponding distribution pipe 6 transmits the detected pressure to the PLC controller 12 in real time. When the detected pressure exceeds the pressure set by the PLC controller 12, which is 0.08 - 0.1 MP, the PLC controller 12 controls the speed reduction of the booster fan 11 of the corresponding connecting branch pipe 10 to reduce the pressure of the overpressure distribution pipe 6. When the detected pressure is lower than the pressure set by the PLC controller 12, which is 0.08 - 0.1 MP, the PLC controller 12 controls the speed increase of the booster fan 11 of the corresponding connecting branch pipe 10 to ensure the pressure of the overpressure distribution pipe 6. In this way, the pressure balance of the multiple distribution pipes 6 can be ensured, and the stability of the pulverized coal entering the blast furnace can be ensured.

[0025] The above shows and describes the basic principle, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A pulverized coal injection system for blast furnace, wherein the compressed air in the compressed air tank (1) is transported through a pipeline to the heat exchanger (2) for heating, and the heated compressed air is transported along the pneumatic conveying pipeline (3) to transport the pulverized coal in the pulverized coal bin (4) to the distributor (5), characterized in that: The flue gas after heat exchange with the heat exchanger (2) is transported along the exhaust pipe (8) to the spiral heating pipe (9) wound around the pneumatic conveying pipeline (3) for heating. The heated flue gas is correspondingly transported to the distribution pipe (6) connected to the upper part of the distributor (5) through a plurality of connecting branch pipes (10). The distribution pipe (6) is provided with a uniform pressure regulating system.

2. The pulverized coal injection system for blast furnace according to claim 1, wherein: The uniform pressure regulating system includes a PLC controller (12). The PLC controller (12) is electrically connected to a pressure detector (13) installed on the corresponding distribution pipe (6), and the PLC controller (12) is electrically connected to a pressurizing fan (11) installed on the connecting branch pipe (10).

3. The pulverized coal injection system for blast furnace according to claim 1, wherein: The shell-side inlet of the heat exchanger (2) is connected to the inlet pipe (7), and the shell-side outlet of the heat exchanger (2) is connected to the exhaust pipe (8).

4. A pulverized coal injection system for blast furnace according to claim 1, characterized in that: The bottom of the pulverized coal bin (4) is connected to the pneumatic conveying pipeline (3) through a discharge pipe.

5. A pulverized coal injection system for blast furnace according to claim 1, characterized in that: Control valves (14) are installed on the pneumatic conveying pipeline (3), the inlet pipe (7), the exhaust pipe (8), and the discharge pipe.

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