A high-efficiency vertical pulverized coal heating device and method

Abstract

The present invention relates to a high-efficiency 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 first-stage fluidizer (3), a first heating section (4) of the heat exchanger, a second-stage fluidizer (5), a second heating section (6) of the heat exchanger, a third-stage fluidizer (7) and a third heating section (8) of the heat exchanger are arranged in sequence from top to bottom between an upper shell (2) of a heat exchanger and a lower shell (9) of a heat exchanger, and a pulverized coal fluidizing pressurizer (10) is arranged at the bottom of the lower shell of the heat exchanger and is connected to an outlet pulverized coal pipeline (11). The beneficial effect of the present invention is that before the pulverized coal from the blast furnace injection pipeline enters the pulverized coal heater, it is not necessary to separate the pulverized coal and nitrogen, and the pulverized coal and nitrogen are heated together. Since the pulverized coal and nitrogen do not need to be separated, the separator equipment is eliminated, the structure of the equipment is simplified, the time for the pulverized coal to be heated is much shorter than the heat transfer time between the pulverized coal and the pulverized coal, the heating efficiency is greatly improved, and the investment cost is correspondingly reduced.

Description

Technical Field

[0001] The invention relates to a high-efficiency vertical pulverized coal 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 is more conducive to widespread promotion and application in production. This is the case with the Chinese patent CN2022110243682 applied by the applicant, entitled "A Energy-Saving Blast Furnace Gas Multi-stage Heating Vertical Pulverized Coal Heating Device and Method". However, the patent application still 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, which increases the construction cost. If the pulverized coal and gas are not separated, it will cause the accumulation and aggregation of materials in the pulverized coal heater; ② Due to the poor thermal conductivity of pulverized coal, the heat exchange area of ​​the pulverized coal heater is large, the heat transfer and heating time between pulverized coal is long, and the efficiency is low; ③ The vertical pulverized coal heater has a complex structure and high investment cost. Summary of the invention

[0003] The purpose of the present invention is to provide a high-efficiency vertical pulverized coal heating device and method. Before the pulverized coal from the blast furnace injection pipeline enters the pulverized coal heater, it is not necessary to separate the pulverized coal and nitrogen, and the pulverized coal and nitrogen are heated together. Since the pulverized coal and nitrogen do not need to be separated, the separator equipment is eliminated, the structure of the equipment is greatly simplified, the investment cost is correspondingly reduced, the time for the pulverized coal to be heated is much shorter than the heat transfer time between the pulverized coal and the pulverized coal, the heating efficiency is greatly improved, the structure of the equipment is further simplified, the investment cost is correspondingly reduced, and the problems existing in the background technology are solved.

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

[0005] A high-efficiency vertical pulverized coal heating method, before the pulverized coal from the blast furnace injection pipeline enters the vertical pulverized coal heating device, it is not necessary to separate the pulverized coal and nitrogen, the pulverized coal and nitrogen mixture enters the vertical pulverized coal heating device together for heating, a fluidizer is arranged on the upper part of the heating section of the vertical pulverized coal heating device to avoid the pulverized coal and nitrogen from agglomerating and piling up, thereby ensuring the pulverized coal heating efficiency; since the pulverized coal and nitrogen do not need to be separated, the separator equipment is eliminated, the structure is simplified, and the equipment investment is reduced; the pulverized coal and gas are heated together, since airflow disturbance occurs after nitrogen heating, the pulverized coal is heated, the pulverized coal is heated more quickly, the heating efficiency is improved, and accordingly, the heat area of ​​the vertical pulverized coal heating device can also be reduced, the equipment structure is further simplified, and the investment cost is correspondingly reduced.

[0006] A high-efficiency vertical pulverized coal heating device, wherein a first-stage fluidizer, a first heating section of the heat exchanger, a second-stage fluidizer, a second heating section of the heat exchanger, a third-stage fluidizer and a third heating section of the heat exchanger are sequentially arranged between an upper shell of a heat exchanger and a lower shell of a heat exchanger from top to bottom, the top of the upper shell of the heat exchanger is connected to an inlet pulverized coal pipeline, and a pulverized coal fluidizing pressurizer is arranged at the bottom of the lower shell of the heat exchanger and is connected to an outlet pulverized coal pipeline; a pulverized coal-nitrogen mixture coming from a blast furnace coal injection pipeline enters the upper shell of the pulverized coal heat exchanger through the inlet pulverized coal pipeline, and the pulverized coal-nitrogen mixture uniformly enters the first-stage fluidizer, the first heating section of the heat exchanger, the second-stage fluidizer, the second heating section of the heat exchanger, the third-stage fluidizer and the third heating section of the heat exchanger in sequence, and the pulverized coal-nitrogen mixture is uniformly arranged in the first-stage fluidizer, the second Under the action of the first-stage fluidizer and the third-stage fluidizer, the pulverized coal and nitrogen mixture is further fluidized by nitrogen, and the pulverized coal is in a suspended state under the action of nitrogen, which avoids the aggregation and accumulation of pulverized coal, resulting in low pulverized coal heating efficiency and poor heating effect. The nitrogen is heated in the first heating section, the second heating section and the third heating section of the heat exchanger, and the nitrogen gas flow is disturbed. The heated nitrogen quickly heats the surrounding pulverized coal particles to the same temperature. The heated nitrogen pulverized coal mixture comes out of the third heating section of the heat exchanger, enters the lower shell of the pulverized coal heat exchanger, and finally enters the pulverized coal fluidization pressurizer. Under the action of fluidizing gas and nitrogen pressurized gas, the pulverized coal and nitrogen are pressed into the pulverized coal pipeline at the blast furnace coal injection outlet and transported to the blast furnace.

[0007] The first-stage fluidizer, the second-stage fluidizer and the third-stage fluidizer have the same structure, and are composed of a flange outer cylinder, an upper sealing plate, a lower sealing plate, a nitrogen inlet pipe and a conical fluidizing cylinder. The upper sealing plate and the lower sealing plate are circular steel plate processed parts, and circular through holes are provided on the surface of the steel plate; the conical fluidizing cylinder is an inverted cone, and is installed between the circular through holes of the upper sealing plate and the lower sealing plate. The flange outer cylinder is connected to the upper sealing plate and the lower sealing plate 31 by welding. The flange outer cylinder and the upper sealing plate, the lower sealing plate and the outer surface of the conical fluidizing cylinder form a closed cavity for circulating nitrogen. Nitrogen enters from the nitrogen inlet pipe and is discharged from the coal powder fluidization channel in each conical fluidizing cylinder.

[0008] The first heating section, the second heating section and the third heating section of the heat exchanger have the same structure, and are composed of high-efficiency heat exchange tubes, upper flange tube sheets, lower flange tube sheets, outer cylinders, corrugated compensators, high-temperature heat source inlets and high-temperature heat source outlets. The high-efficiency heat exchange tubes are connected to the coal powder heating channels of the upper flange tube sheets and the lower flange tube sheets by welding, and the outer cylinders are connected to the upper flange tube sheets and the lower flange tube sheets by welding. The outer cylinders, the upper flange tube sheets, the lower flange tube sheets and the outer surfaces of the high-efficiency heat exchange tubes form a closed cavity for circulating the high-temperature heat source to heat the coal powder and nitrogen in the high-efficiency heat exchange tubes.

[0009] The outer steel pipe of the high-efficiency heat exchange tube is a standard product. A central pipe is arranged inside the steel pipe. A plurality of longitudinal open steel pipes are arranged tangentially between the central pipe and the outer steel pipe of the high-efficiency heat exchange tube. All the longitudinal open steel pipes are connected to the central pipe by welding. The outer surface of the high-efficiency heat exchange tube contacts and transfers heat. Pulverized coal and nitrogen flow through the inner surface of the high-efficiency heat exchange tube and between the central pipe and the longitudinal open steel pipe. In this way, the heating area of ​​the high-efficiency heat exchange tube is increased, and the heat exchange efficiency of the pulverized coal and nitrogen is improved.

[0010] The high temperature heat source is not limited to molten salt, thermal oil, steam, hot flue gas, etc.

[0011] The lower shell of the heat exchanger includes: a baffle, a flow equalizing device, a nitrogen pressurizing pipe and an outer shell. The upper part of the lower shell of the pulverized coal heat exchanger is cylindrical and connected to the high-efficiency heat exchange pipe, and the lower part is a conical fluidizing cylinder, which is connected to the pulverized coal fluidizing pressurizer. The conical fluidizing cylinder is used to further fluidize the pulverized coal to prevent the pulverized coal from agglomerating and piling up. The shape is not limited to various shapes such as conical and cylindrical.

[0012] In order to ensure that the coal powder and nitrogen flow in each high-efficiency heat exchange tube fall evenly and avoid "short circuit" which affects the heat exchange efficiency, a baffle and a flow equalizing device are arranged in the lower shell of the heat exchanger; the baffle 22 is a circular steel plate processed part, and the baffle can be arranged in multiple layers in the lower shell of the heat exchanger. The surface of the steel plate is provided with multiple circular through holes, which are used to block the coal powder and nitrogen flow to avoid excessive local flow rate and the resulting reduction in heat exchange efficiency; the flow equalizing device is composed of multiple annular triangular steel parts concentrically arranged in the lower shell of the heat exchanger, and all the triangular vertices are in one plane. The multiple annular triangular steel parts are superimposed on each other in the vertical direction, leaving a certain gap between each other to prevent the coal powder from falling vertically, resulting in excessive local coal powder falling speed and uneven coal amount.

[0013] The nitrogen pressurizing pipe is arranged below the flow equalizing device. Nitrogen flows in the nitrogen pressurizing pipe to increase the pressure of the lower shell of the heat exchanger and ensure that the pulverized coal and nitrogen are continuously output from the lower shell of the heat exchanger.

[0014] The pulverized coal fluidizing pressurizer comprises a conical fluidizing plate, a booster pressurizing pipeline and a fluidizer outer shell. The conical fluidizing plate is arranged inside the fluidizer outer shell. The upper part of the fluidizer outer shell is connected with the lower shell of the heat exchanger, and the lower part of the fluidizer outer shell is connected with the outlet pulverized coal pipeline through the booster pressurizing pipeline. The conical fluidizing plate is in the shape of an inverted cone, and the conical fluidizing plate is used for circulating nitrogen and pulverized coal.

[0015] The upper shell of the heat exchanger includes: a conical cylinder shell, a guide cone and a guide ring plate; the upper flange of the conical cylinder shell is connected to the imported pulverized coal pipeline, and the lower flange of the conical cylinder shell is connected to the pulverized coal fluidization channel of the first-stage fluidizer; the functions of the conical cylinder shell, the guide cone and the guide ring plate are to change the direction of the pulverized coal and nitrogen airflows, so as to ensure that the nitrogen-coal mixed airflow entering the upper shell of the pulverized coal heat exchanger enters the first-stage fluidizer smoothly and evenly.

[0016] The guide cone is a steel part, which is arranged below the upper flange of the conical cylinder shell. The guide cone has a conical shape and its function is to disperse the nitrogen-coal-powder mixed airflow in the circumferential direction to prevent the nitrogen-coal-powder mixed airflow from directly impacting downward and causing the nitrogen-coal-powder mixed airflow to be unstable.

[0017] The guide ring plate is a steel part, arranged below the guide cone, and is an inverted conical cylinder. Its function is to guide the nitrogen-coal powder mixed airflow to change direction and ensure that the coal powder and nitrogen enter the coal powder fluidization channel of the first-stage fluidizer smoothly and evenly.

[0018] The beneficial effects of the present invention are as follows: before the pulverized coal from the blast furnace injection pipeline enters the pulverized coal heater, it is not necessary to separate the pulverized coal and nitrogen, and the pulverized coal and nitrogen are heated together. Since the pulverized coal and nitrogen do not need to be separated, the separator equipment is eliminated, the structure of the equipment is greatly simplified, the investment cost is correspondingly reduced, the time for the pulverized coal to be heated is much shorter than the heat transfer time between the pulverized coal, the heating efficiency is greatly improved, the structure of the equipment is further simplified, and the investment cost is correspondingly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an overall structural diagram of an embodiment of the present invention;

[0020] Figure 2 This is a structural diagram of the upper shell of the heat exchanger according to an embodiment of the present invention;

[0021] Figure 3 This is a structural diagram of a heating section of a heat exchanger according to an embodiment of the present invention;

[0022] Figure 4 This is a structural diagram of a flange tube sheet according to an embodiment of the present invention;

[0023] Figure 5 This is a structural diagram of the lower shell of the heat exchanger according to an embodiment of the present invention;

[0024] Figure 6 1. It is a structural diagram of a pulverized coal fluidizing pressurizer according to an embodiment of the present invention;

[0025] Figure 7 is a structural diagram of a fluidizer according to an embodiment of the present invention;

[0026] Figure 8 AA is a cross-sectional structural diagram of a fluidizer according to an embodiment of the present invention;

[0027] Fig. 9 This is a structural diagram of a fluidizer BB according to an embodiment of the present invention;

[0028] Fig.10 This is a structural diagram of a high-efficiency heat exchange tube according to an embodiment of the present invention;

[0029] Fig.11 This is a steel tube structure diagram of a high-efficiency heat exchange tube according to an embodiment of the present invention;

[0030] In the figure: inlet pulverized coal pipeline 1, upper shell of heat exchanger 2, first-stage fluidizer 3, first heating section of heat exchanger 4, second-stage fluidizer 5, second heating section of heat exchanger 6, third-stage fluidizer 7, third heating section of heat exchanger 8, lower shell of heat exchanger 9, pulverized coal fluidization pressurizer 10, conical cylinder shell 12, outlet pulverized coal pipeline 11, guide cone 13, guide ring plate 14, high-efficiency heat exchange tube 15, upper flange tube sheet 16, lower flange tube sheet 17, outer cylinder 18, corrugated The groove compensator 19, the high-temperature heat source inlet 20, the high-temperature heat source outlet 21, the baffle 22, the flow equalizing device 23, the nitrogen pressurizing pipe 24, the outer shell 25, the conical fluidizing plate 26, the booster pressurizing pipeline 27, the fluidizer outer shell 28, the flange outer cylinder 29, the upper sealing plate 30, the lower sealing plate 31, the nitrogen inlet pipe 32, the conical fluidizing cylinder 34, the pulverized coal fluidizing channel 35, the center tube 36, the longitudinal open steel pipe 37, the high-temperature heat source 38, and the pulverized coal heating channel 39. DETAILED DESCRIPTION

[0031] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings.

[0032] A high-efficiency vertical pulverized coal heating method, before the pulverized coal from the blast furnace injection pipeline enters the vertical pulverized coal heating device, it is not necessary to separate the pulverized coal and nitrogen, the pulverized coal and nitrogen mixture enters the vertical pulverized coal heating device together for heating, a fluidizer is arranged on the upper part of the heating section of the vertical pulverized coal heating device to avoid the pulverized coal and nitrogen from agglomerating and piling up, thereby ensuring the pulverized coal heating efficiency; since the pulverized coal and nitrogen do not need to be separated, the separator equipment is eliminated, the structure is simplified, and the equipment investment is reduced; the pulverized coal and gas are heated together, since airflow disturbance occurs after nitrogen heating, the pulverized coal is heated, the pulverized coal is heated more quickly, the heating efficiency is improved, and accordingly, the heat area of ​​the vertical pulverized coal heating device can also be reduced, the equipment structure is further simplified, and the investment cost is correspondingly reduced.

[0033] A high-efficiency vertical pulverized coal heating device, wherein a first-stage fluidizer 3, a first heating section 4 of the heat exchanger, a second-stage fluidizer 5, a second heating section 6 of the heat exchanger, a third-stage fluidizer 7 and a third heating section 8 of the heat exchanger are arranged in sequence from top to bottom between an upper shell 2 of the heat exchanger and a lower shell 9 of the heat exchanger, the top of the upper shell 2 of the heat exchanger is connected to an inlet pulverized coal pipeline 1, and a pulverized coal fluidizing pressurizer 10 is arranged at the bottom of the lower shell 9 of the heat exchanger and is connected to an outlet pulverized coal pipeline 11; a pulverized coal-nitrogen mixture coming from a blast furnace coal injection pipeline enters the upper shell 2 of the pulverized coal heat exchanger through the inlet pulverized coal pipeline 1, and the pulverized coal-nitrogen mixture enters the first-stage fluidizer 3, the first heating section 4 of the heat exchanger, the second-stage fluidizer 5, the second heating section 6 of the heat exchanger, the third-stage fluidizer 7 and the third heating section 8 of the heat exchanger in sequence and uniformly, and is discharged into ... Under the action of the fluidizer 3, the second-stage fluidizer 5 and the third-stage fluidizer 7, the pulverized coal and nitrogen mixture is further fluidized by nitrogen. The pulverized coal is in a suspended state under the action of nitrogen, which avoids the aggregation and accumulation of pulverized coal, resulting in low pulverized coal heating efficiency and poor heating effect. The nitrogen is heated in the first heating section 4, the second heating section 6 and the third heating section 8 of the heat exchanger, and the nitrogen gas flow is disturbed. The heated nitrogen quickly heats the surrounding pulverized coal particles to the same temperature. The heated nitrogen pulverized coal mixture comes out of the third heating section 8 of the heat exchanger, enters the lower shell 9 of the pulverized coal heat exchanger, and finally enters the pulverized coal fluidization pressurizer 10. Under the action of the fluidizing gas and the nitrogen pressurized gas, the pulverized coal and nitrogen are pressed into the pulverized coal pipeline 11 at the blast furnace coal injection outlet and transported to the blast furnace.

[0034] The first-stage fluidizer 3, the second-stage fluidizer 5 and the third-stage fluidizer 7 have the same structure, and are composed of a flange outer cylinder 29, an upper sealing plate 30, a lower sealing plate 31, a nitrogen inlet pipe 32 and a conical fluidizing cylinder 34. The upper sealing plate 30 and the lower sealing plate 31 are circular steel plate processed parts, and circular through holes are provided on the surface of the steel plates; the conical fluidizing cylinder 34 is an inverted cone, and is installed between the circular through holes of the upper sealing plate 30 and the lower sealing plate 31. The flange outer cylinder 29 is connected to the upper sealing plate 30 and the lower sealing plate 31 by welding. The flange outer cylinder 29 and the upper sealing plate 30, the lower sealing plate 31 and the outer surface of the conical fluidizing cylinder 34 form a closed cavity for circulating nitrogen. Nitrogen enters from the nitrogen inlet pipe 32 and is discharged from the coal powder fluidizing channel 35 in each conical fluidizing cylinder 34.

[0035] The first heating section 4, the second heating section 6 and the third heating section 8 of the heat exchanger have the same structure, and are composed of a high-efficiency heat exchange tube 15, an upper flange tube sheet 16, a lower flange tube sheet 17, an outer cylinder 18, a corrugated compensator 19, a high-temperature heat source inlet 20 and a high-temperature heat source outlet 21. The high-efficiency heat exchange tube 15 is connected to the coal powder heating channel 39 of the upper flange tube sheet 16 and the lower flange tube sheet 17 by welding, and the outer cylinder 18 is connected to the upper flange tube sheet 16 and the lower flange tube sheet 17 by welding. The outer cylinder 18 and the outer surfaces of the upper flange tube sheet 16, the lower flange tube sheet 17 and the high-efficiency heat exchange tube 15 form a closed cavity for circulating the high-temperature heat source 38 to heat the coal powder and nitrogen in the high-efficiency heat exchange tube 15.

[0036] The outer steel pipe of the high-efficiency heat exchange tube 15 is a standard product. A central tube 36 is arranged inside the steel pipe. A plurality of longitudinal open steel pipes 37 are arranged tangentially between the central tube 36 and the outer steel pipe of the high-efficiency heat exchange tube 15. All longitudinal open steel pipes 37 are connected to the central tube 36 by welding. The outer surface of the high-efficiency heat exchange tube 15 is in contact with heat transfer. Pulverized coal and nitrogen flow through the inner surface of the high-efficiency heat exchange tube 15 and between the central tube 36 and the longitudinal open steel pipes 37. In this way, the heating area of ​​the high-efficiency heat exchange tube 15 is increased, and the heat exchange efficiency of the pulverized coal and nitrogen is improved.

[0037] The high temperature heat source 38 is not limited to molten salt, heat transfer oil, steam, hot flue gas, etc.

[0038] The lower shell 9 of the heat exchanger includes: a baffle 22, a flow equalizing device 23, a nitrogen pressurizing pipe 24 and an outer shell 25. The upper part of the lower shell 9 of the pulverized coal heat exchanger is cylindrical and connected to the high-efficiency heat exchange pipe 15, and the lower part is a conical fluidizing cylinder 34, which is connected to the pulverized coal fluidizing pressurizer 10; the conical fluidizing cylinder 34 is used to further fluidize the pulverized coal to prevent the pulverized coal from agglomerating and piling up, and the appearance is not limited to various shapes such as conical and cylindrical.

[0039] In order to ensure that the coal powder and nitrogen flow in each high-efficiency heat exchange tube 15 fall evenly and avoid "short circuit" which affects the heat exchange efficiency, a baffle 22 and a flow equalizer 23 are arranged in the lower shell 9 of the heat exchanger; the baffle 22 is a circular steel plate processed part, and the baffle can be arranged in multiple layers in the lower shell 9 of the heat exchanger. The surface of the steel plate is provided with multiple circular through holes, which are used to block the coal powder and nitrogen flow to avoid excessive local flow rate and the resulting reduction in heat exchange efficiency; the flow equalizer 23 is composed of multiple annular triangular steel parts concentrically arranged in the lower shell 9 of the heat exchanger, and all the triangular vertices are in one plane. The multiple annular triangular steel parts are superimposed on each other in the vertical direction, leaving a certain gap between each other to prevent the coal powder from falling vertically, resulting in excessive local coal powder falling speed and uneven coal amount.

[0040] The nitrogen pressurizing pipe 24 is arranged below the flow equalizing device 23 . Nitrogen flows in the nitrogen pressurizing pipe 24 to increase the pressure of the lower shell 9 of the heat exchanger and ensure that the pulverized coal and nitrogen are continuously output from the lower shell 9 of the heat exchanger.

[0041] The pulverized coal fluidizing pressurizer 10 comprises a conical fluidizing plate 26, a boosting and pressurizing pipeline 27 and a fluidizer outer shell 28. The conical fluidizing plate 26 is arranged in the fluidizer outer shell 28. The upper part of the fluidizer outer shell 28 is connected to the lower shell 9 of the heat exchanger, and the lower part of the fluidizer outer shell 28 is connected to the outlet pulverized coal pipeline 11. The outlet pulverized coal pipeline 11 is provided with a boosting and pressurizing pipeline 27. The conical fluidizing plate 26 is in the shape of an inverted cone, and the conical fluidizing plate 26 is used to circulate nitrogen and pulverized coal.

[0042] The upper shell 2 of the heat exchanger includes: a conical cylindrical shell 12, a guide cone 13 and a guide ring plate 14; the upper flange of the conical cylindrical shell 12 is connected to the imported pulverized coal pipeline 1, and the lower flange of the conical cylindrical shell 12 is connected to the pulverized coal fluidization channel 35 of the first-stage fluidizer 3; the functions of the conical cylindrical shell 12, the guide cone 13 and the guide ring plate 14 are to change the direction of the pulverized coal and nitrogen airflows, so as to ensure that the nitrogen-pulverized coal mixed airflow entering the upper shell 2 of the pulverized coal heat exchanger smoothly and evenly enters the first-stage fluidizer 3.

[0043] The guide cone 13 is a steel part, which is arranged below the upper flange of the conical cylinder shell 12. The guide cone 13 has a conical shape and its function is to disperse the nitrogen-coal-powder mixed airflow in the circumferential direction to prevent the nitrogen-coal-powder mixed airflow from directly impacting downward and causing the nitrogen-coal-powder mixed airflow to be unstable.

[0044] The guide ring plate 14 is a steel part, which is arranged below the guide cone 13 and is an inverted conical cylinder. Its function is to guide the nitrogen-coal mixed airflow to change direction and ensure that the coal powder and nitrogen enter the coal powder fluidization channel 35 of the first-stage fluidizer 3 smoothly and evenly.

[0045] In the embodiment, the pulverized coal and nitrogen mixture coming from the blast furnace coal injection pipeline enters the upper shell 2 of the pulverized coal heat exchanger through the inlet pulverized coal pipeline 1. Under the action of the guide cone 13 and the guide ring plate 14, the pulverized coal and nitrogen mixture enters the pulverized coal fluidizing channel 35 and the pulverized coal heating channel 39 of the first-stage fluidizer 3, the first heating section 4 of the heat exchanger, the second-stage fluidizer 5, the second heating section 6 of the heat exchanger, the third-stage fluidizer 7 and the third heating section 8 of the heat exchanger in sequence and evenly. Under the action of the first-stage fluidizer 3, the second-stage fluidizer 5 and the third-stage fluidizer 7, the pulverized coal and nitrogen mixture is further fluidized by nitrogen, and the pulverized coal is in a suspended state under the action of nitrogen, thereby avoiding the aggregation and accumulation of the pulverized coal. The phenomenon results in low heating efficiency of pulverized coal and poor heating effect. In the first heating section 4, the second heating section 6 and the third heating section 8 of the heat exchanger, the high-temperature heat source 38 first heats the nitrogen in the high-efficiency heat exchange tube 15. The nitrogen gas flow is disturbed, and the heated nitrogen quickly heats the surrounding pulverized coal particles to the same temperature. The heated nitrogen-pulverized coal mixture comes out of the third heating section 8 of the heat exchanger, enters the lower shell 9 of the pulverized coal heat exchanger, passes through the baffle 22 and the flow equalizing device 23, and finally enters the pulverized coal fluidizing pressurizer 10. Under the action of the fluidizing gas and the nitrogen pressurized gas, the pulverized coal and nitrogen are pressed into the pulverized coal pipeline 11 at the blast furnace coal injection outlet and transported to the blast furnace.

[0046] In the embodiment, the flange outer cylinder of the first-stage fluidizer 3 is connected to the lower flange of the conical cylinder shell 12, and is connected to the upper flange tube sheet 16 of the first heating section 4 of the heat exchanger. The conical fluidizing cylinder 34 and the coal powder fluidizing channel 35 are connected to the coal powder heating channel 39 of the upper flange tube sheet 16 of the first heating section 4 of the heat exchanger and the high-efficiency heat exchange tube 15 for circulating nitrogen and coal powder.

[0047] The flange outer cylinder of the second-stage fluidizer 5 is connected to the lower flange tube sheet of the first heating section 4 of the heat exchanger and the upper flange tube sheet of the second heating section 6 of the heat exchanger. The conical fluidizing cylinder and the pulverized coal fluidizing channel are connected to the pulverized coal heating channels and high-efficiency heat exchange pipes of the first heating section 4 of the heat exchanger and the second heating section 6 of the heat exchanger for circulating nitrogen and pulverized coal.

[0048] The flange outer cylinder of the third-stage fluidizer 7 is connected to the lower flange tube sheet of the second heating section 6 of the heat exchanger and the upper flange tube sheet of the third heating section 6 of the heat exchanger. The conical fluidizing cylinder 34 and the pulverized coal fluidizing channel 35 are connected to the pulverized coal heating channels and high-efficiency heat exchange pipes of the second heating section 5 of the heat exchanger and the third heating section 7 of the heat exchanger for circulating nitrogen and pulverized coal.

[0049] The conical fluidizing tube 34 is used to further fluidize the coal powder to prevent the coal powder from agglomerating and piling up. The shape is not limited to various shapes such as conical, cylindrical and flat fluidizing plate.

Claims

1. A high-efficiency vertical pulverized coal heating device, characterized in that: A first-stage fluidizer (3), a first heating section (4) of the heat exchanger, a second-stage fluidizer (5), a second heating section (6) of the heat exchanger, a third-stage fluidizer (7) and a third heating section (8) of the heat exchanger are arranged in sequence from top to bottom between the upper shell (2) of the heat exchanger and the lower shell (9) of the heat exchanger. The top of the upper shell (2) of the heat exchanger is connected to the inlet pulverized coal pipeline (1). The bottom of the lower shell (9) of the heat exchanger is provided with a pulverized coal fluidizing pressurizer (10) and is connected to the outlet pulverized coal pipeline (11). The pulverized coal and nitrogen mixture coming from the blast furnace coal injection pipeline enters the upper shell (2) of the pulverized coal heat exchanger through the inlet pulverized coal pipeline (1). The pulverized coal and nitrogen mixture enters the first-stage fluidizer (3), the first heating section (4) of the heat exchanger, the second-stage fluidizer (5), the second heating section (6) of the heat exchanger, the third-stage fluidizer (7) and the third heating section (8) of the heat exchanger in sequence. In the third heating section (8) of the heat exchanger, under the action of the first-stage fluidizer (3), the second-stage fluidizer (5) and the third-stage fluidizer (7), the pulverized coal nitrogen mixture is further fluidized by nitrogen, and the pulverized coal is suspended under the action of nitrogen, thereby preventing the pulverized coal from agglomerating and piling up. In the first heating section (4), the second heating section (6) and the third heating section (8) of the heat exchanger, the nitrogen is heated, and the nitrogen gas flow is disturbed. The heated nitrogen quickly heats the surrounding pulverized coal particles to the same temperature. The heated nitrogen pulverized coal mixture comes out of the third heating section (8) of the heat exchanger, enters the lower shell (9) of the pulverized coal heat exchanger, and finally enters the pulverized coal fluidization pressurizer (10). Under the action of the fluidizing gas and the nitrogen pressurizing gas, the pulverized coal and the nitrogen are pressed into the pulverized coal pipeline (11) at the blast furnace coal injection outlet and transported to the blast furnace. The first-stage fluidizer (3), the second-stage fluidizer (5) and the third-stage fluidizer (7) have the same structure, and are composed of a flange outer cylinder (29), an upper sealing plate (30), a lower sealing plate (31), a nitrogen inlet pipe (32) and a conical fluidizing cylinder (34). The upper sealing plate (30) and the lower sealing plate (31) are circular steel plate processed parts, and circular through holes are provided on the surface of the steel plate. The conical fluidizing cylinder (34) is an inverted cone and is installed on the upper sealing plate (30). The flange outer cylinder (29) is connected to the upper sealing plate (30) and the lower sealing plate (31) by welding, and the flange outer cylinder (29) and the upper sealing plate (30), the lower sealing plate (31) and the outer surface of the conical fluidizing cylinder (34) form a closed cavity for circulating nitrogen. The nitrogen enters from the nitrogen inlet pipe (32) and is discharged from the coal powder fluidizing channel (35) in each conical fluidizing cylinder (34).

2. A high-efficiency vertical pulverized coal heating device according to claim 1, characterized in that; The first heating section (4), the second heating section (6) and the third heating section (8) of the heat exchanger have the same structure, and are composed of a high-efficiency heat exchange tube (15), an upper flange tube sheet (16), a lower flange tube sheet (17), an outer cylinder (18), a corrugated compensator (19), a high-temperature heat source inlet (20) and a high-temperature heat source outlet (21); the high-efficiency heat exchange tube (15) is connected to the pulverized coal heating channel (39) of the upper flange tube sheet (16) and the lower flange tube sheet (17) by welding; the outer cylinder (18) is connected to the upper flange tube sheet (16) and the lower flange tube sheet (17) by welding; the outer cylinder (18) and the upper flange tube sheet (16), the lower flange tube sheet (17) and the outer surface of the high-efficiency heat exchange tube (15) form a closed cavity for circulating the high-temperature heat source (38) to heat the pulverized coal and nitrogen in the high-efficiency heat exchange tube (15).

3. A high-efficiency vertical pulverized coal heating device according to claim 1, characterized in that The heat exchanger lower shell (9) comprises: a baffle (22), a flow balancing device (23), a nitrogen pressurizing pipe (24) and an outer shell (25); the upper portion of the pulverized coal heat exchanger lower shell (9) is cylindrical and communicates with the high-efficiency heat exchange pipe (15); the lower portion of the pulverized coal heat exchanger lower shell (9) is conical and communicates with the pulverized coal fluidizing pressurizer (10); the baffle (22) and the flow balancing device (23) are provided in the pulverized coal heat exchanger lower shell (9); and the nitrogen pressurizing pipe (24) is provided below the flow balancing device (23).

4. A high-efficiency vertical pulverized coal heating device according to claim 3, characterized in that: The baffle (22) is a circular steel plate processed part. The baffle can be arranged in multiple layers in the lower shell (9) of the heat exchanger. The surface of the steel plate is provided with multiple circular through holes, which are used to block the flow of coal powder and nitrogen to avoid excessive local flow rate and the resulting reduction in heat exchange efficiency. The flow equalizing device (23) is composed of multiple annular triangular steel parts concentrically arranged in the lower shell (9) of the heat exchanger. All the triangular vertices are in a plane. The multiple annular triangular steel parts are superimposed on each other in the vertical direction, leaving a certain gap between each other, so as to prevent the coal powder from falling vertically, resulting in excessive local coal powder falling speed and uneven coal amount.

5. The high-efficiency vertical pulverized coal heating device according to claim 1 is characterized in that: The pulverized coal fluidizing pressurizer (10) comprises a conical fluidizing plate (26), a boosting and pressurizing pipeline (27) and a fluidizer outer shell (28); the conical fluidizing plate (26) is arranged in the fluidizer outer shell (28); the upper part of the fluidizer outer shell (28) is connected to the lower shell (9) of the heat exchanger; the lower part of the fluidizer outer shell (28) is connected to the outlet pulverized coal pipeline (11) through the boosting and pressurizing pipeline (27); the conical fluidizing plate (26) is in the shape of an inverted cone; nitrogen and pulverized coal are circulated in the conical fluidizing plate (26).

6. A high-efficiency vertical pulverized coal heating device according to claim 1, characterized in that The heat exchanger upper shell (2) comprises: a conical cylindrical shell (12), a guide cone (13) and a guide ring plate (14); the upper flange of the conical cylindrical shell (12) is connected to the inlet pulverized coal pipeline (1), and the lower flange of the conical cylindrical shell (12) is connected to the pulverized coal fluidization channel (35) of the first-stage fluidizer (3); the conical cylindrical shell (12), the guide cone (13) and the guide ring plate (14) function to change the direction of the pulverized coal and nitrogen flows, thereby ensuring that the nitrogen-coal mixed flow entering the pulverized coal heat exchanger upper shell (2) enters the first-stage fluidizer (3) smoothly and evenly.

7. A high-efficiency vertical pulverized coal heating device according to claim 2, characterized in that: A central tube (36) is arranged inside the outer steel tube of the high-efficiency heat exchange tube (15), and a plurality of longitudinal open steel tubes (37) are arranged tangentially between the central tube (36) and the outer steel tube of the high-efficiency heat exchange tube (15). All longitudinal open steel tubes (37) are connected to the central tube (36) by welding. The outer surface of the high-efficiency heat exchange tube (15) is in contact with the heat transfer, and coal powder and nitrogen flow between the inner surface of the high-efficiency heat exchange tube (15), the central tube (36), and the longitudinal open steel tubes (37).

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