A vertical pulverized coal heating device and method

Abstract

The present invention relates to a vertical pulverized coal heating device and method, and belongs to the technical field of coal injection in metallurgical ironmaking blast furnaces. The technical scheme is: a small portion of pulverized coal and nitrogen are separated and first enter a bag filter (11) for nitrogen and pulverized coal separation, and the pulverized coal enters a vertical pulverized coal heater (12); after heating, the pulverized coal passes through a pulverized coal regulating valve (14) and enters a lower injection tank (5) of a vertical nitrogen pulverized coal heater (4), where it is mixed with most of the pulverized coal and nitrogen heated by the vertical nitrogen pulverized coal heater (4), and then output from the injection tank (5) to the blast furnace through the fluidization and boosting of nitrogen. The beneficial effects of the present invention are: ensuring uniform flow of pulverized coal injected into the blast furnace, thereby ensuring improved pulverized coal combustion efficiency, reducing fuel ratio, and saving energy and reducing consumption; at the same time, further increasing the heat source for heating pulverized coal, thereby further increasing the pulverized coal temperature.

Description

Technical Field

[0001] The invention relates to a vertical coal powder heating device and method, belonging to the technical field of coal injection in metallurgical ironmaking blast furnaces. Background Art

[0002] At present, in the field of metallurgical ironmaking technology, blast furnace pulverized coal injection heating technology can effectively improve the combustion efficiency of pulverized coal and reduce the fuel ratio of blast furnaces. Through actual production application, the energy-saving and consumption-reducing effect is remarkable, especially the vertically arranged pulverized coal heating device. Since the pulverized coal heater is arranged vertically, it has more advantages, such as smooth pulverized coal transportation, low accident and failure rate, small footprint, and more conducive to widespread promotion and application in production. This is the case with the Chinese patent CN2022110243682 applied by me, entitled "An Energy-Saving Blast Furnace Gas Multi-stage Heating Vertical Pulverized Coal Heating Device and Method" and the Chinese patent CN202211552583X, entitled "An Efficient Vertical Pulverized Coal Heating Device and Method". However, the two patent applications still have shortcomings. Chinese patent CN 2022110243682, entitled "An energy-saving blast furnace gas multi-stage heating vertical pulverized coal heating device and method", has the following shortcomings: ① Before the pulverized coal from the blast furnace injection pipeline enters the pulverized coal heater, it is necessary to separate the pulverized coal and gas, separate most of the pulverized coal and nitrogen, and pulverize and heat them separately, which increases the construction cost and the equipment cost is high; ② Due to the poor thermal conductivity of pulverized coal, the heat exchange area of ​​the pulverized coal heater is large, which also increases the equipment cost, and the heat transfer and heating time between pulverized coal is long, and the heating efficiency is low; the advantage is that the amount of pulverized coal output from the pulverized coal heater can be adjusted and controlled, and the conical pin in the pulverized coal flow rate adjustment device moves up and down to adjust the flow area of ​​the fixed orifice pulverized coal, which is the same as the principle of the regulating valve, thereby controlling the pulverized coal flow rate, and the pulverized coal injected into the blast furnace is more uniform, the combustion rate of pulverized coal is also improved, and the fuel consumption of the blast furnace is reduced. Chinese patent CN202211552583X, entitled "A high-efficiency vertical pulverized coal heating device and method", has the following shortcomings: the pulverized coal flow rate cannot adjust and control the amount of pulverized coal coming from the blast furnace coal injection pipeline. Due to the large fluctuations in the output of pulverized coal from the blast furnace coal injection pipeline, the combustion rate of the pulverized coal entering the blast furnace is unstable, the pulverized coal combustion efficiency is low, and the blast furnace fuel consumption is increased. Summary of the invention

[0003] The purpose of the present invention is to provide a vertical pulverized coal heating device and method, which ensures that the flow rate of pulverized coal sprayed into the blast furnace is uniform, thereby ensuring the improvement of pulverized coal combustion efficiency, reducing fuel ratio, saving energy and reducing consumption; at the same time, further increasing the temperature of the heat source for heating pulverized coal, thereby further increasing the temperature of pulverized coal, and solving the above-mentioned technical problems existing in the existing technology.

[0004] The technical solution of the present invention is:

[0005] A vertical pulverized coal heating method, before the pulverized coal from the blast furnace coal injection inlet main line enters the vertical nitrogen pulverized coal heater, a small part of the pulverized coal and nitrogen are separated through the inlet branch line, introduced into a bag dust collector and the vertical pulverized coal heater, and most of the pulverized coal and nitrogen enter the vertical nitrogen pulverized coal heater; the small part of the pulverized coal and nitrogen separated first enters the bag dust collector for nitrogen and pulverized coal separation, the nitrogen is discharged from the bag dust collector, and the pulverized coal enters the vertical pulverized coal heater; after being heated by the vertical pulverized coal heater, the pulverized coal is discharged from the lower shell of the vertical pulverized coal heater, passes through the pulverized coal regulating valve, enters the lower injection tank of the vertical nitrogen pulverized coal heater, and mixes with the pulverized coal after passing through the vertical pulverized coal heater. Most of the pulverized coal heated by the nitrogen pulverized coal heater is mixed with nitrogen, fluidized in the fluidizing bin and pressurized, and then output from the injection tank to the blast furnace through the fluidization and boosting of nitrogen; the pulverized coal flow rate discharged from the lower shell of the vertical pulverized coal heater is adjusted by adjusting the opening of the pulverized coal regulating valve; if the pulverized coal flow rate injected into the blast furnace is less than the set flow rate, the pulverized coal regulating valve opening is increased, and the amount of coal input into the injection tank is increased; if the pulverized coal flow rate injected into the blast furnace is greater than the set flow rate, the pulverized coal regulating valve opening is reduced or completely closed, and the amount of coal input into the injection tank is reduced or no pulverized coal is input, thereby ensuring the uniformity of the pulverized coal output from the injection tank and improving the combustion efficiency of the pulverized coal.

[0006] The fluidizing and boosting nitrogen is heated by the heat of the slag iron hook in front of the blast furnace. The heated nitrogen first enters the nitrogen energy storage tank, exchanges heat with the energy storage material in the nitrogen energy storage tank, and then enters the vertical nitrogen pulverized coal heater, the fluidizing bin and the booster. While playing the role of fluidization and boosting, it brings heat into the pulverized coal to further increase the temperature of the pulverized coal.

[0007] A vertical pulverized coal heating device, a blast furnace coal injection inlet main line, a vertical nitrogen pulverized coal heater upper shell, a vertical nitrogen pulverized coal heater, a blowing tank, a fluidized bin and an output pipeline of the vertical nitrogen pulverized coal heater are connected in sequence, and the special feature of the device is that the blast furnace coal injection inlet main line leads to an inlet branch line, and the inlet branch line is connected to the blowing tank through the vertical pulverized coal heater, the vertical pulverized coal heater lower shell, the pulverized coal regulating valve and the vertical pulverized coal heater output pipeline.

[0008] Furthermore, the inlet branch pipeline is connected to the vertical pulverized coal heater through a bag filter.

[0009] Furthermore, the fluidizing bin, booster and vertical nitrogen pulverized coal heater are matched with a nitrogen heated fluidizing booster system. The nitrogen heated fluidizing booster system adopts the slag groove in front of the blast furnace for heating. The nitrogen pipeline is inserted into the slag groove or on the slag groove cover plate. The heat of the blast furnace iron and slag is used to heat the nitrogen in the nitrogen energy storage tank. The heated nitrogen enters the pulverized coal fluidizing bin, booster and vertical nitrogen pulverized coal heater through the pipeline, and heats the pulverized coal while fluidizing and boosting.

[0010] Furthermore, the nitrogen energy storage tank comprises an energy storage tank nitrogen pipe bundle, a nitrogen energy storage tank shell, a nitrogen energy storage tank upper shell and a nitrogen energy storage tank lower shell. The nitrogen energy storage tank shell is arranged between the nitrogen energy storage tank upper shell and the nitrogen energy storage tank lower shell, and the energy storage tank nitrogen pipe bundle is arranged in the nitrogen energy storage tank shell.

[0011] The positive effects of the present invention are as follows: before the pulverized coal from the blast furnace injection pipeline enters the vertical nitrogen pulverized coal heater, the present invention separates a small portion of the pulverized coal and nitrogen, and stores the separated portions in the vertical pulverized coal heater to adjust the flow rate of the pulverized coal input into the blast furnace, while most of the pulverized coal and nitrogen do not need to be separated and directly enter the vertical nitrogen pulverized coal heater; by adjusting the flow rate of the pulverized coal input into the blast furnace, the flow rate of the pulverized coal injected into the blast furnace is ensured to be uniform, thereby ensuring the improvement of the pulverized coal combustion efficiency, reducing the fuel ratio, and saving energy and reducing consumption; at the same time, a nitrogen heating energy storage tank is added to stabilize the nitrogen heating temperature and increase the temperature of other heating pulverized coal heat sources, thereby achieving good energy-saving and consumption-reducing effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a process flow chart of an embodiment of the present invention;

[0013] Figure 2 This is a structural diagram of a spray tank according to an embodiment of the present invention;

[0014] Figure 3 Schematic diagram of heating nitrogen in slag and iron trench according to an embodiment of the present invention;

[0015] Figure 4 Schematic diagram of heating nitrogen with a slag iron trench cover plate according to an embodiment of the present invention;

[0016] Figure 5 is a schematic structural diagram of a nitrogen energy storage tank according to an embodiment of the present invention;

[0017] In the figure: blast furnace coal injection inlet main line 1, inlet pulverized coal flowmeter 2, vertical nitrogen pulverized coal heater upper shell 3, vertical nitrogen pulverized coal heater 4, injection tank 5, fluidized bin 6, vertical nitrogen pulverized coal heater output pipeline 7, booster 8, outlet pulverized coal flowmeter 9, inlet branch pipeline 10, bag filter 11, vertical pulverized coal heater 12, vertical pulverized coal heater lower shell 13, pulverized coal regulating valve 14, vertical pulverized coal heater output pipeline 15, nitrogen heating fluidization boosting system 16, slag iron ditch 17, slag iron ditch cover 18, injection tank lower pulverized coal pipe 19, nitrogen heating pipe 20, nitrogen energy storage tank 21, energy storage tank nitrogen pipe bundle 22, nitrogen energy storage tank shell 23, nitrogen energy storage tank upper shell 24, nitrogen energy storage tank lower shell 25. DETAILED DESCRIPTION

[0018] The present invention will be further described below through embodiments in conjunction with the accompanying drawings.

[0019] A vertical pulverized coal heating method, before the pulverized coal from the blast furnace coal injection inlet main line 1 enters the vertical nitrogen pulverized coal heater 4, a small portion of the pulverized coal and nitrogen are first separated through the inlet branch line 10, and introduced into the bag dust collector 11 and the vertical pulverized coal heater 12, and most of the pulverized coal and nitrogen enter the vertical nitrogen pulverized coal heater 4; the small portion of the pulverized coal and nitrogen separated first enters the bag dust collector 11 to separate the nitrogen and pulverized coal, the nitrogen is discharged from the bag dust collector 11, and the pulverized coal enters the vertical pulverized coal heater 12; after the pulverized coal is heated by the vertical pulverized coal heater 12, it is discharged from the lower shell 13 of the vertical pulverized coal heater, passes through the pulverized coal regulating valve 14, and enters the lower injection tank 5 of the vertical nitrogen pulverized coal heater 4 , mixed with most of the pulverized coal and nitrogen heated by the vertical nitrogen pulverized coal heater 4, pressurized after fluidization in the fluidizing bin 6, and output from the injection tank 5 to the blast furnace through the fluidization and boosting of nitrogen; by adjusting the opening of the pulverized coal regulating valve 14, the pulverized coal flow rate discharged from the lower shell 13 of the vertical pulverized coal heater is adjusted; if the pulverized coal flow rate injected into the blast furnace is less than the set flow rate, the opening of the pulverized coal regulating valve 14 is increased, and the amount of coal input into the injection tank 5 is increased; if the pulverized coal flow rate injected into the blast furnace is greater than the set flow rate, the opening of the pulverized coal regulating valve 14 is reduced or completely closed, and the amount of coal input into the injection tank 5 is reduced or no pulverized coal is input, thereby ensuring the uniformity of the pulverized coal output from the injection tank and improving the combustion efficiency of the pulverized coal.

[0020] The fluidizing and boosting nitrogen is heated by the heat of the slag iron hook in front of the blast furnace. The heated nitrogen first enters the nitrogen energy storage tank, exchanges heat with the energy storage material in the nitrogen energy storage tank, and then enters the vertical nitrogen pulverized coal heater 4, the fluidizing bin 6 and the booster 8. While playing the role of fluidization and boosting, it brings heat into the pulverized coal to further increase the temperature of the pulverized coal.

[0021] A vertical pulverized coal heating device, wherein a blast furnace coal injection inlet main line 1, a vertical nitrogen pulverized coal heater upper shell 3, a vertical nitrogen pulverized coal heater 4, a blowing tank 5, a fluidizing bin 6 and a vertical nitrogen pulverized coal heater output pipeline 7 are connected in sequence, and the device is special in that: the blast furnace coal injection inlet main line 1 leads to an inlet branch line 10, and the inlet branch line 10 is connected to the blowing tank 5 through a vertical pulverized coal heater 12, a vertical pulverized coal heater lower shell 13, a pulverized coal regulating valve 14 and a vertical pulverized coal heater output pipeline 15.

[0022] The inlet branch pipeline 10 is connected to the vertical pulverized coal heater 12 through a bag filter 11 .

[0023] The fluidizing bin 6, booster 8 and vertical nitrogen pulverized coal heater 4 are matched with a nitrogen heating fluidizing booster system 16. The nitrogen heating fluidizing booster system 16 adopts the slag groove 17 in front of the blast furnace for heating. The nitrogen pipeline 20 is inserted into the slag groove 17 or on the slag groove cover 18. The heat of iron and slag from the blast furnace is used to heat the nitrogen in the nitrogen energy storage tank 21. The heated nitrogen enters the pulverized coal fluidizing bin 6, booster 8 and vertical nitrogen pulverized coal heater through the pipeline, and heats the pulverized coal while fluidizing and boosting.

[0024] The nitrogen energy storage tank 21 includes an energy storage tank nitrogen pipe bundle 22, a nitrogen energy storage tank shell 23, a nitrogen energy storage tank upper shell 24 and a nitrogen energy storage tank lower shell 25. The nitrogen energy storage tank shell 23 is arranged between the nitrogen energy storage tank upper shell 24 and the nitrogen energy storage tank lower shell 25, and the energy storage tank nitrogen pipe bundle 22 is arranged in the nitrogen energy storage tank shell 23.

[0025] The vertical nitrogen pulverized coal heater output pipeline 7 is provided with a booster 8 and an outlet pulverized coal flow meter 9.

[0026] In the embodiment, the vertical nitrogen pulverized coal heater of the present invention is consistent with Chinese patent CN202211552583X, entitled "A High-efficiency Vertical Pulverized Coal Heating Device and Method". The heat exchanger of the vertical nitrogen pulverized coal heater can be provided with one or more sections, and a fluidizer can be provided between the heat exchanger sections.

[0027] The upper shell of the vertical nitrogen pulverized coal heater of the present invention is consistent with the upper shell of the heat exchanger in Chinese patent CN202211552583X, entitled "A High-efficiency Vertical Coal Powder Heating Device and Method".

[0028] The injection tank of the present invention is basically the same as the lower shell of the heat exchanger in Chinese patent CN202211552583X, entitled "A High-efficiency Vertical Coal Powder Heating Device and Method". The difference is that a injection tank lower coal pipe 19 connected to the vertical coal powder heater is added on the basis of the lower shell of the heat exchanger.

[0029] The fluidizing bin of the present invention is basically consistent with the pulverized coal fluidizing pressurizer in Chinese patent CN202211552583X, entitled "A High-efficiency Vertical Coal Powder Heating Device and Method".

[0030] The vertical pulverized coal heater of the present invention is the same as the pulverized coal heating section in Chinese patent CN 2022110243682, entitled "An energy-saving blast furnace gas multi-stage heating vertical pulverized coal heating device and method", and the pulverized coal heating section can be set to one section or multiple sections.

[0031] The lower shell of the vertical pulverized coal heater of the present invention is basically the same as the lower shell of the heat exchanger in Chinese patent CN 2022110243682, entitled "An energy-saving blast furnace gas multi-stage heating vertical pulverized coal heating device and method".

[0032] The booster, pulverized coal regulating valve and bag filter are all general products.

[0033] The nitrogen heating fluidized boosting system includes a nitrogen energy storage tank, a slag ditch, a slag ditch cover, a nitrogen heating tank, etc., and adopts the slag ditch in front of the blast furnace for heating. The nitrogen pipeline is inserted into the slag ditch or on the slag ditch cover, and the heat of iron and slag from the blast furnace is used to heat the nitrogen. The heated nitrogen first enters the nitrogen energy storage tank through the pipeline to exchange heat with the energy storage material of the energy storage tank, and then enters the pulverized coal fluidization bin and the booster. While fluidizing and boosting, the pulverized coal is also heated.

[0034] The nitrogen energy storage tank comprises a nitrogen pipe bundle of the energy storage tank, an upper shell of the nitrogen energy storage tank, a lower shell of the nitrogen energy storage tank, an outer shell of the nitrogen energy storage tank and energy storage materials, etc. Nitrogen flows in the nitrogen pipe bundle of the energy storage tank, the upper shell of the nitrogen energy storage tank and the lower shell of the nitrogen energy storage tank, and heat storage materials are stored outside the nitrogen pipe bundle of the energy storage tank and between the outer shell of the nitrogen energy storage tank.

[0035] The energy storage material is not limited to molten salt, thermal oil or graphite energy storage material.

[0036] The slag iron ditch is not limited to various shapes of slag iron ditch currently used in blast furnaces, and the nitrogen pipeline is not limited to various carbon steel and stainless steel pipes.

[0037] The slag ditch cover plate 18 is not limited to various shapes of slag ditch covers currently used in blast furnaces, and the nitrogen pipeline is not limited to various carbon steel and stainless steel pipes.

[0038] The heating heat source system of the vertical pulverized coal heater 12 and the vertical nitrogen pulverized coal heater 4 is a universal heat source, not limited to various heat sources, such as hot flue gas, steam, thermal oil, etc.

[0039] The inlet branch pipeline 10 is not limited to the branch pipeline separated from the coal injection inlet main pipeline 1 and the upper shell of the vertical nitrogen pulverized coal heater.

Claims

1. A vertical pulverized coal heating method, characterized in that: The blast furnace coal injection inlet main line (1), the vertical nitrogen pulverized coal heater upper shell (3), the vertical nitrogen pulverized coal heater (4), the blowing tank (5), the fluidizing chamber (6) and the vertical nitrogen pulverized coal heater output pipeline (7) are connected in sequence; the blast furnace coal injection inlet main line (1) leads to an inlet branch line (10); the inlet branch line (10) is connected to the blowing tank (5) through the vertical pulverized coal heater (12), the vertical pulverized coal heater lower shell (13), the pulverized coal regulating valve (14) and the vertical pulverized coal heater output pipeline (15); the inlet branch line (10) is connected to the vertical pulverized coal heater (12) through a bag filter (11); the fluidizing chamber (6), the booster (8) and the vertical nitrogen pulverized coal heater (4) are matched with a nitrogen heating fluidized booster system (16); the nitrogen heating fluidized booster system (16) The method adopts the method of heating the slag groove (17) in front of the blast furnace, inserting a nitrogen pipeline (20) into the slag groove (17) or onto a slag groove cover plate (18), utilizing the heat of iron and slag from the blast furnace to heat nitrogen in a nitrogen energy storage tank (21), and the heated nitrogen enters the pulverized coal fluidization bin (6), the booster (8) and the vertical nitrogen pulverized coal heater (4) through the pipeline, and heats the pulverized coal while fluidizing and boosting. The nitrogen energy storage tank (21) comprises an energy storage tank nitrogen pipe bundle (22), a nitrogen energy storage tank shell (23), a nitrogen energy storage tank upper shell (24) and a nitrogen energy storage tank lower shell (25), wherein the nitrogen energy storage tank shell (23) is arranged between the nitrogen energy storage tank upper shell (24) and the nitrogen energy storage tank lower shell (25), and the nitrogen energy storage tank shell (23) is provided with an energy storage tank nitrogen pipe bundle (22). The specific steps are as follows: Before the pulverized coal from the blast furnace coal injection inlet main line (1) enters the vertical nitrogen pulverized coal heater (4), a small portion of the pulverized coal and nitrogen are separated through the inlet branch line (10) and introduced into the bag filter (11) and the vertical pulverized coal heater (12), and most of the pulverized coal and nitrogen enter the vertical nitrogen pulverized coal heater (4); the small portion of the pulverized coal and nitrogen separated first enters the bag filter (11) for nitrogen and pulverized coal separation, the nitrogen is discharged from the bag filter (11), and the pulverized coal enters the vertical pulverized coal heater (12); the pulverized coal is heated by the vertical pulverized coal heater (12), discharged from the lower shell (13) of the vertical pulverized coal heater, and enters the lower injection tank (5) of the vertical nitrogen pulverized coal heater (4) after passing through the pulverized coal regulating valve (14). The pulverized coal is mixed with the majority of the pulverized coal heated by the vertical nitrogen pulverized coal heater (4) and the nitrogen, and is pressurized after fluidization in the fluidizing chamber (6). The pulverized coal is then output from the injection tank (5) to the blast furnace through the fluidization and boosting of the nitrogen. The flow rate of the pulverized coal discharged from the lower shell (13) of the vertical pulverized coal heater is adjusted by adjusting the opening of the pulverized coal regulating valve (14). If the flow rate of the pulverized coal injected into the blast furnace is less than the set flow rate, the opening of the pulverized coal regulating valve (14) is increased, and the amount of coal input into the injection tank (5) is increased. If the flow rate of the pulverized coal injected into the blast furnace is greater than the set flow rate, the opening of the pulverized coal regulating valve (14) is reduced or completely closed, and the amount of coal input into the injection tank (5) is reduced or no pulverized coal is input, thereby ensuring the uniformity of the pulverized coal output from the injection tank and improving the combustion efficiency of the pulverized coal.

2. A vertical pulverized coal heating method according to claim 1, characterized in that: The fluidizing and boosting nitrogen is heated by the heat of the slag iron hook in front of the blast furnace. The heated nitrogen first enters the nitrogen energy storage tank, exchanges heat with the energy storage material in the nitrogen energy storage tank, and then enters the vertical nitrogen pulverized coal heater (4), the fluidizing bin (6) and the booster (8). While playing the role of fluidizing and boosting, it brings heat into the pulverized coal to further increase the temperature of the pulverized coal.

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