Fluidized bed pulverized coal pyrolysis furnace and pyrolysis method

Abstract

This invention relates to the field of low-rank coal fractionation and utilization, and discloses a fluidized bed pulverized coal pyrolysis furnace and pyrolysis method. The fluidized bed pulverized coal pyrolysis furnace includes: a pyrolysis furnace body, with a fluidizing gas inlet at the bottom and a gas outlet at the top; multiple pulverized coal raw material inlets arranged circumferentially and leading into the pyrolysis furnace bed, and multiple high-temperature semi-coke inlets arranged circumferentially and leading into the bottom of the pyrolysis furnace bed; and a circulating semi-coke outlet at the top. This fluidized bed pulverized coal pyrolysis furnace, when used for low-rank coal pyrolysis, can efficiently and cleanly convert low-rank coal into semi-coke, coal tar, and coal gas, thereby increasing the coal tar yield.

Description

Technical Field

[0001] This invention relates to the field of low-rank coal fractionation and utilization, specifically to a fluidized bed pulverized coal pyrolysis furnace and pyrolysis method. Background Technology

[0002] my country has relatively abundant coal reserves. Therefore, the potential amount of coal tar produced as a byproduct of low-rank coal utilization is huge, which can play a significant role in alleviating my country's dependence on foreign oil.

[0003] Currently, gasification and combustion processes use low-rank coal, but most do not produce coal tar as a byproduct. Semi-coke technology produces coal tar as a byproduct, but also generates a large amount of semi-coke, and the raw material must be lump coal, which does not match the particle size distribution produced by mechanized coal mining. Furthermore, the semi-coke process is relatively outdated, and its production efficiency and environmental protection standards do not meet modern requirements.

[0004] Fluidized bed pyrolysis uses pulverized coal as raw material, has a fast pyrolysis reaction rate, and with reasonable process arrangement, the amount of pollution emissions is greatly reduced, which can achieve the level of green process.

[0005] Application No. 201910905164.1, entitled "Circulating Fluidized Bed Pulverized Coal Pyrolysis-Gasification Device and Method," describes a circulating fluidized bed pulverized coal pyrolysis-gasification device and method. The device is connected to a fluidized bed pyrolysis furnace via a feeder and a feed inclined tube. A fluidized bed gasifier is connected to the fluidized bed pyrolysis furnace via a pyrolysis inclined tube. A fast bed gasifier has its lower inlet connected to the upper outlet of the fluidized bed gasifier. A fluidized bed combustion chamber has its upper inlet connected to the lower outlet of the fluidized bed gasifier. A fine powder settling / stripping unit is located outside the fast bed gasifier and connected to the fluidized bed pyrolysis furnace via a gasification inclined tube. This circulating fluidized bed pulverized coal pyrolysis-gasification device and method features high carbon conversion rate, high gasification intensity, high pulverized coal utilization rate, wide adaptability to gasified coal types, rational energy utilization, and stable and efficient operation.

[0006] Application number CN202011377851.X, entitled: A high-efficiency comprehensive utilization process system and method for pulverized coal, including a circulating fluidized bed boiler, a pulverized coal drying mechanism, a circulating fluidized bed pyrolysis furnace, a semi-coke gasification mechanism, a tar recovery mechanism, and a coal gas purification unit. Through the rational design of the process system and method, the heat generated during the pulverized coal pyrolysis process is fully recovered and utilized, enabling the combined system consisting of semi-coke combustion, semi-coke gasification, pulverized coal drying, and circulating fluidized bed pyrolysis of pulverized coal to achieve stable operation and achieve energy-saving and high-efficiency comprehensive utilization.

[0007] In summary, none of the existing fluidized bed pyrolysis furnaces mentioned above have addressed the impact of cold and hot materials entering the furnace on the temperature distribution of the fluidized bed, nor have they addressed the impact of the vertical relationship between cold and hot materials entering the furnace, thus preventing further increases in coal tar production. Summary of the Invention

[0008] The purpose of this invention is to overcome the problem that the coal tar yield in existing fluidized bed pyrolysis furnaces cannot be further increased, and to provide a fluidized bed pulverized coal pyrolysis furnace that can efficiently and cleanly convert low-rank coal into semi-coke, coal tar and coal gas when used for low-rank coal pyrolysis, thereby increasing the coal tar yield.

[0009] To achieve the above objectives, the first aspect of the present invention provides a fluidized bed pulverized coal pyrolysis furnace, which includes: a pyrolysis furnace body, wherein the bottom end of the pyrolysis furnace body is configured as a fluidizing gas inlet, the top end of the pyrolysis furnace body is configured as a gas outlet, the lower part of the pyrolysis furnace body is provided with a plurality of pulverized coal raw material inlets arranged circumferentially and entering the pyrolysis furnace bed, and a plurality of high-temperature semi-coke inlets arranged circumferentially and entering the bottom of the pyrolysis furnace bed, and the upper part of the pyrolysis furnace body is provided with a circulating semi-coke outlet.

[0010] Preferably, both the high-temperature semi-coke inlet and the pulverized coal raw material inlet are connected to a feeding mechanism; the feeding mechanism includes: a feeding pipeline and a plurality of feeding short pipes connected to the feeding pipeline, the feeding short pipes being connected to the corresponding high-temperature semi-coke inlet or the pulverized coal raw material inlet.

[0011] Preferably, the feed pipe connected to the pulverized coal inlet includes: a first inclined pipe and a first annular conduit concentrically arranged with the pyrolysis furnace body; the feed pipe connected to the high-temperature semi-coke inlet includes: a second inclined pipe and a second annular conduit concentrically arranged with the pyrolysis furnace body; multiple feed short pipes are radially connected and located inside the first annular conduit and the second annular conduit; the first inclined pipe is used to introduce pulverized coal, and the second inclined pipe is used to introduce high-temperature semi-coke.

[0012] Preferably, the feed pipe is obliquely downward along the direction toward the pyrolysis furnace body, and forms an angle of 30-60° with the horizontal plane.

[0013] Preferably, both the first annular conduit and the second annular conduit are formed by combining at least two arc-shaped conduit segments, each arc-shaped conduit segment is provided with a plurality of feed short pipes, and each arc-shaped conduit segment is provided with a first inclined pipe or a second inclined pipe.

[0014] Preferably, the inner diameter of the pyrolysis furnace body is 2-20m, the height-to-diameter ratio is 2-6, the vertical distance between the circulating semi-coke outlet and the bottom of the pyrolysis furnace body is 5-30m, and the high-temperature semi-coke inlet is located 0.2-1.5m below the pulverized coal raw material inlet.

[0015] Preferably, the fluidizing gas inlet is a cone-shaped structure with a gas distribution plate inside.

[0016] Preferably, the upper end of the pyrolysis furnace body is provided with a settling section, the lower part of the settling section is provided with a constricted cone structure, the angle between the cone surface of the cone structure and the horizontal plane is 60-85°, and the ratio of the upper part of the settling section to the inner diameter of the pyrolysis furnace body is 1.05-1.35.

[0017] Preferably, an external semi-coke outlet is also provided on the pyrolysis furnace body at a position 1-5m above the circulating semi-coke outlet.

[0018] A second aspect of the present invention provides a pyrolysis method using the fluidized bed pulverized coal pyrolysis furnace, the pyrolysis method comprising:

[0019] 1) Crush the raw coal into small particles with a diameter of 0.05-1.0 mm;

[0020] 2) The small pulverized coal particles from step 1) are carried by loosened gas and flow into the pyrolysis furnace bed through multiple pulverized coal feed inlets distributed in a circumferential direction;

[0021] At the same time, high-temperature semi-coke at a temperature of 800-950℃ is carried by loosening gas and flows into the bottom of the pyrolysis furnace bed through multiple circumferentially distributed high-temperature semi-coke inlets.

[0022] At the same time, fluidizing gas is conveyed upward through the fluidizing gas inlet;

[0023] 3) Under the action of fluidizing gas, the hot and cold materials are mixed evenly, so that the bed temperature is maintained between 500-700℃, and the raw coal undergoes pyrolysis reaction under a pressure of 0.05-0.5MPa.

[0024] Through the above technical solution, pulverized coal feedstock is dispersed into the pyrolysis furnace bed through multiple pulverized coal feedstock inlets, and high-temperature semi-coke is dispersed into the bottom of the pyrolysis furnace bed through multiple high-temperature semi-coke inlets. Fluidized gas enters the pyrolysis furnace body through the fluidized gas inlet. The fluidized gas fully mixes and exchanges heat between the dispersed pulverized coal feedstock and the high-temperature semi-coke in the lower part of the pyrolysis furnace body. The high-temperature semi-coke provides heat to the pulverized coal feedstock, and a pyrolysis reaction occurs simultaneously. The semi-coke is discharged through the set circulating semi-coke outlet and becomes high-temperature feedstock after being heated. Thus, when the fluidized bed pulverized coal pyrolysis furnace is used for the pyrolysis of low-rank coal, it can efficiently and cleanly convert low-rank coal into semi-coke, coal tar, and coal gas, thereby increasing the yield of coal tar. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a preferred embodiment of a fluidized bed pulverized coal pyrolysis furnace;

[0026] Figure 2This is a schematic diagram of another preferred embodiment of a fluidized bed pulverized coal pyrolysis furnace;

[0027] Figure 3 This is a schematic diagram of a preferred embodiment of the feeding mechanism;

[0028] Figure 4 This is a schematic diagram of another preferred embodiment of the feeding mechanism.

[0029] Explanation of reference numerals in the attached figures

[0030] 1-Pyrolysis furnace body; 2-Feeding mechanism; 3-Fluidizing gas inlet; 4-Gas outlet; 5-Fluidizing gas; 6-First annular conduit; 7-Feeding short pipe; 8-Second inclined pipe; 9-Circulating semi-coke outlet; 10-External semi-coke outlet; 11-First inclined pipe; 12-Second annular conduit; 13-Settling section; 14-Semi-annular conduit. Detailed Implementation

[0031] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0032] In this invention, unless otherwise stated, directional terms such as "up, down, left, right, front, back, inside, outside" in the terminology only represent the orientation of the term in its normal use or are common terms understood by those skilled in the art, and should not be regarded as a limitation on the term.

[0033] See Figure 1 The fluidized bed pulverized coal pyrolysis furnace shown includes: a pyrolysis furnace body 1, with a fluidizing gas inlet 3 at the bottom and a gas outlet 4 at the top. The lower part of the pyrolysis furnace body 1 is provided with multiple pulverized coal raw material inlets distributed circumferentially and leading into the pyrolysis furnace bed, and multiple high-temperature semi-coke inlets distributed circumferentially and leading into the bottom of the pyrolysis furnace bed. The upper part of the pyrolysis furnace body 1 is provided with a circulating semi-coke outlet 9.

[0034] Through the implementation of the above technical solution, pulverized coal feedstock is dispersed into the pyrolysis furnace bed from multiple pulverized coal feedstock inlets, and high-temperature semi-coke is dispersed into the bottom of the pyrolysis furnace bed from multiple high-temperature semi-coke inlets. Fluidized gas 5 enters the pyrolysis furnace body 1 from the fluidized gas inlet 3. The fluidized gas 5 fully mixes and exchanges heat between the dispersed pulverized coal feedstock and the high-temperature semi-coke in the lower part of the pyrolysis furnace body 1. The high-temperature semi-coke provides heat to the pulverized coal feedstock, and a pyrolysis reaction occurs simultaneously. The semi-coke is discharged through the set circulating semi-coke outlet 9 and becomes high-temperature feedstock after being heated. Thus, when the fluidized bed pulverized coal pyrolysis furnace is used for the pyrolysis of low-rank coal, it can efficiently and cleanly convert low-rank coal into semi-coke, coal tar, and coal gas, thereby increasing the yield of coal tar.

[0035] In this embodiment, to further improve the feeding effect of high-temperature semi-coke and pulverized coal raw materials, both the high-temperature semi-coke inlet and the pulverized coal raw material inlet are connected to a feeding mechanism 2. The feeding mechanism 2 includes a feeding pipeline and multiple feeding short pipes 7 connected to the feeding pipeline. The feeding short pipes 7 are connected to the corresponding high-temperature semi-coke inlet or pulverized coal raw material inlet. The raw materials enter from the feeding pipeline, are dispersed to various positions in the circumferential direction by the feeding short pipes 7, and then enter the pyrolysis furnace bed. The size and number of feeding short pipes 7 depend on the size of the pyrolysis furnace body 1.

[0036] The structure of the feed pipeline can be varied. For example, in one embodiment, the feed pipeline connected to the pulverized coal inlet includes: a first inclined pipe 11 and a first annular conduit 6 concentrically arranged with the pyrolysis furnace body 1; the feed pipeline connected to the high-temperature semi-coke inlet includes: a second inclined pipe 8 and a second annular conduit 12 concentrically arranged with the pyrolysis furnace body 1; multiple feed short pipes 7 are radially connected and located inside the first annular conduit 6 and the second annular conduit 12; the first inclined pipe 11 is used to introduce pulverized coal, and the second inclined pipe 8 is used to introduce high-temperature semi-coke.

[0037] The circulating semi-coke is fed into the second annular guide tube 12 through the second inclined tube 8, and then fed into the pyrolysis furnace body 1 through multiple feed short tubes 7 arranged radially on the inner side of the second annular guide tube 12. This can increase the dispersion of material conveying and increase the mixing effect. Of course, in order to improve the mixing uniformity of raw materials, the multiple feed short tubes 7 can be distributed at equal intervals.

[0038] Pulverized coal raw material is fed into the first annular conduit 6 through the first inclined pipe 11, and then fed into the pyrolysis furnace body 1 through multiple feed short pipes 7 arranged radially on the inner side of the first annular conduit 6. This can increase the dispersion of material conveying and increase the mixing effect. Of course, in order to improve the mixing uniformity of raw materials, the multiple feed short pipes 7 can be evenly distributed.

[0039] By adopting a decentralized feeding method, the high and low temperature materials entering the furnace are dispersed in the circumference and then enter the bed through the feed short pipe 7. This avoids the formation of high temperature or low temperature zones by a single material entering the bed. At the same time, the vertical relationship between the cold and hot materials entering the furnace is specified, allowing the high temperature materials to enter from the bottom and the cold materials to enter from a certain distance above, so that the cold and hot materials are mixed evenly, which is conducive to heat and mass transfer.

[0040] In this embodiment, to further enhance the mixing effect of the raw materials, the feed pipe 7 is obliquely downward along the direction towards the pyrolysis furnace body 1, forming an angle of 30-60° with the horizontal plane. This arrangement ensures that the conveying direction of the fluidizing gas 5 forms an obtuse angle with the feeding direction of the raw materials, thereby improving the mixing effect. The size and number of feed pipes 7 depend on the size of the pyrolysis furnace body 1.

[0041] In another embodiment, both the first annular conduit 6 and the second annular conduit 12 are formed by combining at least two arc-shaped conduit segments. Each arc-shaped conduit segment is provided with multiple feed short pipes 7, and each arc-shaped conduit segment is provided with either the first inclined pipe 11 or the second inclined pipe 8. Figure 3 and Figure 4 As shown, the arc-shaped conduit is a semi-circular conduit 14, representing two different connection methods between the first inclined tube 11 or the second inclined tube 8 and the semi-circular conduit 14. The angle between the first inclined tube 11 or the second inclined tube 8 and the horizontal plane is in the range of 40-75°. Of course, in order to smoothly feed the raw material into the pyrolysis furnace body 1, a loosening gas inlet can be provided on the corresponding first inclined tube 11 or second inclined tube 8. This loosening gas can be water vapor or circulating pyrolysis gas.

[0042] In this embodiment, the pyrolysis furnace body 1 can be of various sizes depending on the processing capacity requirements. For example, the inner diameter of the pyrolysis furnace body 1 can be 2-20m, while the inner diameter of an industrial furnace is generally 8-17m, with a height-to-diameter ratio of 2-6. The vertical distance between the circulating semi-coke outlet 9 and the bottom of the pyrolysis furnace body 1 is 5-30m, and the high-temperature semi-coke inlet is located 0.2-1.5m below the pulverized coal raw material inlet. Of course, the pyrolysis furnace body 1 can also be configured with other sizes and proportions as needed.

[0043] In this embodiment, to enhance the inflow of fluidizing gas 5, the fluidizing gas inlet 3 is a cone shape with a gas distribution plate inside. The high-temperature semi-coke inlet can be located at the bottom cone of the pyrolysis furnace body 1, while the pulverized coal raw material inlet is located 0.2-1.5m above the pipeline. The gas distribution plate is used to uniformly distribute the fluidizing gas 5.

[0044] In this embodiment, in order to increase the settling effect at the upper end of the pyrolysis furnace body 1, such as... Figure 2 As shown, the upper end of the pyrolysis furnace body 1 is provided with a settling section 13, and the lower part of the settling section 13 is provided with a constricted cone structure. The angle between the cone surface of the cone structure and the horizontal plane is 60-85°, and the ratio of the upper part of the settling section 13 to the inner diameter of the pyrolysis furnace body 1 is 1.05-1.35.

[0045] In this embodiment, to properly dispose of excess coke in the pyrolysis furnace, an external coke discharge outlet 10 is provided on the pyrolysis furnace body 1, located 1-5m above the circulating coke outlet 9. The coke material flowing out of the circulating coke outlet 9 enters a gasifier or combustion heating furnace, and after its temperature is increased, it enters the pyrolysis furnace body 1 through a high-temperature coke inlet. The external coke discharge outlet 10 is used to discharge excess coke. When the circulating coke is gasified, the external coke discharge outlet 10 does not discharge coke. For example, if excess coke in the pyrolysis furnace body 1 is discharged from the external coke discharge outlet 10, and the pyrolysis furnace body 1 is coupled to the gasifier or combustion heating furnace through the circulating coke outlet 9, the external coke discharge outlet 10 can be omitted or closed. When coupled with gasification technology, the coke can be simultaneously converted into syngas.

[0046] A second aspect of the present invention provides a pyrolysis method using the fluidized bed pulverized coal pyrolysis furnace, the pyrolysis method comprising:

[0047] 1) Crush the raw coal into small particles with a diameter of 0.05-1.0 mm;

[0048] 2) The small pulverized coal particles from step 1) are carried by loosened gas and flow into the pyrolysis furnace bed through multiple pulverized coal feed inlets distributed in a circumferential direction;

[0049] At the same time, high-temperature semi-coke at a temperature of 800-950℃ is carried by loosening gas and flows into the bottom of the pyrolysis furnace bed through multiple circumferentially distributed high-temperature semi-coke inlets.

[0050] At the same time, fluidizing gas 5 is conveyed upward through fluidizing gas inlet 3;

[0051] 3) Under the action of fluidizing gas 5, the hot and cold materials are mixed evenly, so that the bed temperature is maintained between 500-700℃, and the raw coal undergoes pyrolysis reaction under a pressure of 0.05-0.5MPa.

[0052] Specifically, the raw coal is pulverized into small particles ranging from 0.05 to 1.0 mm, or even smaller particles within a narrower range of this size. The pulverized coal is connected to the pulverized coal inlet via a hopper, pipeline, or valve, while a small amount of loosening gas is introduced into the pipeline. The pulverized coal flows towards the pyrolysis furnace bed under the influence of the gas.

[0053] The high-temperature semi-coke comes from a combustion furnace or gasifier, with a temperature range of 800-950℃. It is connected to the high-temperature semi-coke inlet through pipelines and valves. At the same time, a small amount of loosening gas is introduced into the pipeline. The high-temperature semi-coke flows to the bottom of the pyrolysis furnace bed under the action of the gas. Under the action of fluidizing gas 5, the hot and cold materials are mixed evenly, so that the bed temperature is maintained between 500-700℃, and further optimized to between 550-600℃. The raw coal undergoes a pyrolysis reaction, releasing gas and coal tar.

[0054] Gas flows out of the pyrolysis furnace from gas outlet 4 and is processed downstream. Circulating semi-coke flows out from circulating semi-coke outlet 9 and flows into the combustion furnace or gasification furnace through a conduit. After the temperature rises, it returns. Excess semi-coke from the pyrolysis furnace is discharged from the external semi-coke outlet 10. If the pyrolysis furnace and the gasification furnace are coupled, the external semi-coke outlet 10 can be omitted.

[0055] Example 1 (Data source: Experiment No.: 120040-2021-10569-049)

[0056] The pyrolysis furnace body 1 adopts a cold-mold reactor, with an inner diameter of 0.5m and a bed height of 3m in the cold-mold test bed;

[0057] The main pipe of the feed pipeline used to transport pulverized coal raw materials has a diameter of 25mm and a length of 1.75m around the cold mold reactor. The feed short pipe 7 has a diameter of 10mm and a length of 100mm. There are 90 feed short pipes 7 distributed at equal intervals.

[0058] The main pipe of the feed pipe used to transport high-temperature semi-coke has a diameter of 60mm and a length of 1.2m around the lower cone of the cold mold reactor. There are 7 feed short pipes with a diameter of 15mm and a length of 100mm, and the number of them is 80 and they are evenly distributed.

[0059] The vertical distance between the circulating semi-coke outlet 9 and the bottom of the cold mold reactor is 1.7m, and the outlet pipe diameter is 60mm. The external discharge semi-coke outlet 10 is 3m from the bottom of the reactor, and the pipe diameter is 25mm.

[0060] Cold mold fluidizing gas volume 5: 235.5 Nm 3 / h, the particle size of pulverized coal is in the range of 0.1-0.6mm, the pulverized coal feed rate is 0.5t / h, which is the same as the amount of discharged material;

[0061] When the circulating material rate is 2-3 t / h, the bed material is stable and can maintain a steady state.

[0062] Example 2

[0063] The same hot reactor of the same size as in Example 1 was used, with low-rank coal as the raw material (analytical data are shown in Table 1).

[0064]

[0065] Table 1 Analysis of Raw Coal

[0066] The pulverized coal feed rate is 0.5 t / h, the pyrolysis furnace temperature is 560℃, the pressure is 0.15 MPa, the combustion furnace temperature is 850℃, and the circulating fluidized gas flow rate is 125.5 Nm³. 3 The pyrolysis furnace is operating normally, with a pyrolysis gas yield of 110.5 Nm³ / h. 3 / t, coal tar yield 7.1%, semi-coke yield 69.1%, that is, the semi-coke discharge flow rate is 0.35t / h.

[0067] Comparative Example 1

[0068] Other conditions were the same as in Example 2, except that the high-temperature material and the cold material entered the bed from their respective separate inlets. The results showed that the pyrolysis gas yield was 95.1 Nm / t, the coal tar yield was 6.3%, and the semi-coke yield was 72.5%. This indicates incomplete pyrolysis, with the coal tar yield decreasing by 0.8 percentage points.

[0069] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0071] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A fluidized bed pulverized coal pyrolysis furnace, characterized in that, The fluidized bed pulverized coal pyrolysis furnace includes: a pyrolysis furnace body (1), the bottom end of the pyrolysis furnace body (1) is configured as a fluidizing gas inlet (3), the top end of the pyrolysis furnace body (1) is configured as a gas outlet (4), the lower part of the pyrolysis furnace body (1) is provided with multiple pulverized coal raw material inlets distributed circumferentially and entering the pyrolysis furnace bed and multiple high-temperature semi-coke inlets distributed circumferentially and entering the bottom of the pyrolysis furnace bed, and the upper part of the pyrolysis furnace body (1) is provided with a circulating semi-coke outlet (9). The fluidized bed pulverized coal pyrolysis furnace also includes a first inclined tube (11) for feeding pulverized coal raw materials and a second inclined tube (8) for feeding high-temperature semi-coke. The first inclined tube (11) is connected to the pulverized coal raw material inlet through a feed short tube (7), and the second inclined tube (8) is connected to the high-temperature semi-coke inlet through a feed short tube (7). Multiple feed short tubes (7) are arranged radially. The fluidizing gas inlet (3) is a cone, and the high-temperature semi-coke inlet is located at the cone part at the bottom of the pyrolysis furnace body (1); The upper end of the pyrolysis furnace body (1) is provided with a settling section (13), and the lower part of the settling section (13) is provided with a constricted cone structure. The high-temperature semi-coke inlet is located 0.2-1.5m below the pulverized coal raw material inlet.

2. The fluidized bed pulverized coal pyrolysis furnace according to claim 1, characterized in that, Both the high-temperature semi-coke inlet and the pulverized coal raw material inlet are connected to a feeding mechanism (2). The feeding mechanism (2) includes: a feeding pipeline and a plurality of feeding short pipes (7) connected to the feeding pipeline.

3. The fluidized bed pulverized coal pyrolysis furnace according to claim 2, characterized in that, The feed pipeline connected to the pulverized coal raw material inlet includes: a first inclined pipe (11) connected to the pulverized coal raw material inlet and a first annular conduit (6) arranged concentrically with the pyrolysis furnace body (1). The feed pipeline connected to the high-temperature semi-coke inlet includes: a second inclined pipe (8) connected to the feed pipeline and a second annular conduit (12) concentrically arranged with the pyrolysis furnace body (1). The feed short pipes (7) are arranged in a radial manner inside the first annular conduit (6) and the second annular conduit (12); The first inclined tube (11) is used to introduce pulverized coal raw material, and the second inclined tube (8) is used to introduce high-temperature semi-coke material.

4. The fluidized bed pulverized coal pyrolysis furnace according to claim 3, characterized in that, The feed pipe (7) is obliquely downward along the direction toward the pyrolysis furnace body (1) and forms an angle of 30-60° with the horizontal plane.

5. The fluidized bed pulverized coal pyrolysis furnace according to claim 3, characterized in that, The first annular conduit (6) and the second annular conduit (12) are both formed by combining at least two arc-shaped conduits. Each arc-shaped conduit is provided with a plurality of feed short pipes (7) and each arc-shaped conduit is provided with the first inclined pipe (11) or the second inclined pipe (8).

6. The fluidized bed pulverized coal pyrolysis furnace according to claim 1, characterized in that, The vertical distance between the circulating semi-coke outlet (9) and the bottom of the pyrolysis furnace body (1) is 5-30m.

7. The fluidized bed pulverized coal pyrolysis furnace according to claim 1, characterized in that, A gas distribution plate is provided inside the fluidizing gas inlet (3).

8. The fluidized bed pulverized coal pyrolysis furnace according to claim 1, characterized in that, The angle between the conical surface of the vertebral structure and the horizontal plane is 60-85°.

9. The fluidized bed pulverized coal pyrolysis furnace according to any one of claims 1-8, characterized in that, An external semi-coke outlet (10) is also provided on the pyrolysis furnace body (1) at a position 1-5m above the circulating semi-coke outlet (9).

10. A pyrolysis method, characterized in that, The pyrolysis method uses the fluidized bed pulverized coal pyrolysis furnace according to any one of claims 1-9, and the pyrolysis method includes: 1) Crush the raw coal into small particles with a diameter of 0.05-1.0 mm; 2) The small pulverized coal particles from step 1) are carried by loosened gas and flow into the pyrolysis furnace bed through multiple pulverized coal feed inlets distributed in a circumferential direction; At the same time, high-temperature semi-coke at a temperature of 800-950℃ is carried by loosening gas and flows into the bottom of the pyrolysis furnace bed through multiple circumferentially distributed high-temperature semi-coke inlets. At the same time, fluidizing gas (5) is conveyed upward through the fluidizing gas inlet (3); 3) Under the action of fluidizing gas (5), the hot and cold materials are mixed evenly, so that the bed temperature is maintained between 500-700℃, and the raw coal undergoes pyrolysis reaction under a pressure of 0.05-0.5MPa.

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