Fluidized gasification-pyrolysis transport coupled reaction apparatus

Abstract

The utility model discloses a fluidization gasification - pyrolysis conveying coupling's reaction unit, including air chamber, cloth air distribution board, bubbling fluidized bed reactor, transition section, conveyor I, screw feeder, conveyor II and gasification furnace, the material outlet of screw feeder is connected with the one side end of bubbling fluidized bed reactor, and the other side end of bubbling fluidized bed reactor is connected with conveyor I through conveyor II, and the bottom of bubbling fluidized bed reactor is connected with the top of air chamber, and cloth air distribution board sets up between bubbling fluidized bed reactor and air chamber, and the top of bubbling fluidized bed reactor is connected with conveyor I through transition section, and the end of conveyor I is in communication with the inlet of gasification furnace. Through the coupling of two section conveyors, realize half -coke granule pyrolysis conveying integration, have both the advantage that bubbling fluidized bed granule stays long, gas -solid contact is sufficient, and have the advantage that external circulation flow rate is high, and half -coke granule pyrolysis is sufficient, provide the support for the efficient gasification of subsequent gasification furnace.

Description

Technical Field

[0001] This utility model relates to fluidized bed devices in energy and chemical processes, specifically to a fluidized gasification-pyrolysis transport coupled reaction device. Background Technology

[0002] Bubbling fluidized bed reactors are a classic gas-solid two-phase fluidized bed reactor widely used in industry. They are valued for their excellent gas-solid contact, long particle residence time, and strong heat and mass transfer performance. Material flow rate is typically controlled by adjusting the speed of the screw feeder, which necessitates increasing the size of the screw feeder, thus increasing construction costs and the risk of instability. Pneumatic conveying devices, on the other hand, operate at higher gas velocities. During operation, material in the pneumatic conveying device is quickly carried out of the bed at high gas velocities, preventing particle aggregation at the bottom of the bed. Pneumatic conveying devices feature a large external circulation flow rate and low gas-solid backmixing, and have been applied in coal gasification and chemical looping combustion in recent years. However, they also have some drawbacks: due to the high operating air velocity, the reactor is generally relatively tall to ensure sufficient material residence time, resulting in a less compact layout and higher initial investment; simultaneously, the high air velocity across the entire height of the pneumatic conveying device leads to higher fan energy consumption, reducing the economic efficiency of reactor operation. Whether it's a bubbling fluidized bed, a circulating fluidized bed, or other gas-solid fluidized beds evolved from circulating fluidized beds, it's impossible to simultaneously achieve optimal residence time and flow rate for solid materials. Reactors with longer residence times often have lower flow rates, while reactors with higher flow rates often have insufficient particle residence time. To date, no reports have been found on technologies that can simultaneously control the material residence time in the reactor, adjust the reactor's circulation flow rate, enhance semi-coke pyrolysis, and ensure efficient, economical, and safe reactor operation. Utility Model Content

[0003] The purpose of this invention is to provide a fluidized gasification-pyrolysis conveying coupled reaction device, which classifies the semi-coke produced by the bubbling fluidized bed into a pneumatic conveyor according to its size, thereby improving the semi-coke flow rate and reactivity.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is: a fluidized gasification-pyrolysis conveying coupled reaction device, which includes a wind chamber, a wind distribution plate, a bubbling fluidized bed reactor, a transition section, a conveyor I, a screw feeder, a conveyor II, and a gasifier;

[0005] The material outlet of the screw feeder is connected to one side of the bubbling fluidized bed reactor. The other side of the bubbling fluidized bed reactor is connected to conveyor I through conveyor II. The bottom of the bubbling fluidized bed reactor is connected to the top of the air chamber. The air distribution plate is set between the bubbling fluidized bed reactor and the air chamber. The top of the bubbling fluidized bed reactor is connected to conveyor I through a transition section. The end of conveyor I is connected to the inlet of the gasifier.

[0006] Furthermore, the upper part of the bubbling fluidized bed reactor body is a dilute phase zone, the lower part is a dense phase zone, and the lower part of the dense phase zone is an air distribution plate.

[0007] Furthermore, the bottom wall of the air chamber is provided with a fluidizing air inlet, and the fluidizing air introduced is one or more of air, oxygen, water vapor and carbon dioxide.

[0008] Furthermore, the fluidizing air is a mixture of CO2 and O2, wherein the air equivalent ratio is 0.1 to 0.4 and the carbon dioxide concentration is 20% to 50%.

[0009] Furthermore, the first end of conveyor I is connected to the transition section located at the top, and then conveyor I descends along one side of the bubbling fluidized bed reactor, finally connecting its tail end to the inlet of the gasifier; the outlet end of conveyor II is connected to the descending section of conveyor I.

[0010] Furthermore, the material outlet height of the screw feeder is higher than the inlet height of the conveyor II.

[0011] Furthermore, the conveyor II is inclined downward at 5 to 60 degrees, and the inlet height of the conveyor II is higher than the initial bed material accumulation height in the bubbling fluidized bed reactor; the initial bed material is one or more of quartz sand, dolomite and olivine.

[0012] Furthermore, conveyors I and II are pipes lined with a high-temperature wear-resistant coating, and the pipe diameters of conveyors I and II are smaller than the pipe diameter of the bubbling fluidized bed reactor.

[0013] Furthermore, the wind speed in conveyor I is 5-20 m / s, the temperature is 400-600℃, the particle speed is 5-25 m / s, and the gas-solid ratio is 15-30, while the gas-solid ratio in conveyor II is 0-15.

[0014] Furthermore, the fluidizing velocity of the bubbling fluidized bed reactor is 1–3.5 m / s, the temperature is 700–1000 °C, and the operating pressure is a slightly positive pressure of 40–60 kPa or a pressurized pressure of 0–4 MPa.

[0015] Furthermore, the bubbling fluidized bed reactor adopts the operation mode of bubbling bed or turbulent bed, and the conveyor I adopts the operation mode of pneumatic conveying or rapid fluidized bed.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) Effective control of the flow rate of solid materials and the residence time of materials in the reactor. Compared with traditional gas-solid fluidized bed reactors, this invention couples a bubbling fluidized bed and two-stage conveyors, thus possessing both the advantages of long particle residence time in bubbling fluidized beds and the characteristics of high particle flow rate in pneumatic conveying devices. In the bubbling fluidized bed reactor, the residence time of fine particles is greater than 40s, while coarse particles enter the conveyor through pressure difference and backmixing. In the device of this invention, fluidizing air enters the bubbling fluidized bed reactor from the air chamber through the air distribution plate, and then enters conveyor I through the transition section. The diameter of the high-temperature wear-resistant coated pipes of conveyors I and II is smaller than the pipe diameter of the fluidized bed reactor, thus the air velocity in conveyors I and II is greater than the air velocity in the fluidized bed reactor section. The material enters the bubbling fluidized bed reactor through a screw feeder. The terminal velocity of smaller particles (the final velocity of the particles as they freely settle in the airflow) is much lower than the fluidizing air velocity, so they are carried into conveyor I by the fluidizing air. The terminal velocity of larger particles is higher than the fluidizing air velocity, so they cannot be carried away by the fluidizing air and will enter conveyor II due to the backmixing and pressure difference of the fluidized bed.

[0018] (2) Effective integration of material pyrolysis and conveying. Compared with traditional gasification devices, this invention achieves integrated pyrolysis and conveying of semi-coke particles through the coupling of two conveyors. It combines the advantages of long particle residence time and sufficient gas-solid contact in a bubbling fluidized bed reactor with the advantages of high external circulation flow rate and sufficient pyrolysis of semi-coke particles. In this invention, the material undergoes pyrolysis in the bubbling fluidized bed reactor, effectively extending the gas-solid contact time and enhancing the gas-solid contact efficiency. The pyrolysis residue is conveyed by the conveyor to the next stage high-temperature gasifier, which is more conducive to the gasification reaction. The gasification reaction temperature of the bubbling fluidized bed is 700-1000℃, and the reaction temperature of conveyors I and II is 500-800℃. Therefore, by achieving effective pyrolysis of the material through the bubbling fluidized bed and conveying the pyrolysis residue through the conveyor, the integrated control of material pyrolysis and conveying can be effectively realized.

[0019] (3) Simple and compact structure. The reaction device of this utility model consists of a wind chamber, a wind distribution plate, a bubbling fluidized bed reactor, a transition section, a conveyor I, a cyclone separator, a conveyor II, and a high-temperature gasifier. It has a simple structure, low overall height, compact spatial arrangement, low initial investment, and good application prospects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] The diagram is labeled as follows: 1-air chamber, 2-air distribution plate, 3-bubbling fluidized bed reactor, 4-transition section, 5-conveyor I, 6-screw feeder, 7-conveyor II, 8-gasifier. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1 As shown, this utility model discloses a fluidized gasification-pyrolysis conveying coupled reaction device, comprising a wind chamber 1, an air distribution plate 2, a bubbling fluidized bed reactor 3, a transition section 4, a conveyor I5, a screw feeder 6, a conveyor II7, and a gasifier 8. The material outlet of the screw feeder 6 is connected to one end of the bubbling fluidized bed reactor 3. The other end of the bubbling fluidized bed reactor 3 is connected to the conveyor I5 via the conveyor II7. Material enters the bubbling fluidized bed reactor 3 through the screw feeder 6. Fine particles, under the action of fluidizing air, pass through the transition section 4 and enter the conveyor I5, while coarse particles, under the action of pressure difference, fall directly into the conveyor I5 via the conveyor II7. The bottom end of the bubbling fluidized bed reactor 3 is connected to the top end of the wind chamber 1, and the top end of the bubbling fluidized bed reactor 3 is connected to the conveyor I5 via the transition section 4. The bubbling fluidized bed reactor 3 can be operated as a bubbling bed or a turbulent bed. The conveyor I5 can be operated as a pneumatic conveyor or a rapid fluidized bed. The air distribution plate 2 is connected between the bubbling fluidized bed reactor 3 and the air chamber 1. The wall of the air chamber 1 is provided with a fluidizing air inlet. The fluidizing air enters the air chamber 1 through the fluidizing air inlet, and then enters the bubbling fluidized bed reactor 3 through the air distribution plate 2.

[0024] Preferably, the flow rate of the bubbling fluidized bed reactor 3 is lower than that of the conveyor I5, thereby increasing the particle velocity within the conveyor I5 and facilitating pneumatic conveying or rapid fluidization.

[0025] Preferably, the material outlet height of the screw feeder on the left side of the bubbling fluidized bed reactor 3 is higher than the inlet height of the conveyor II7. The conveyor II7 is inclined downward at 5 to 60 degrees, and the inlet height of the conveyor II7 is higher than the initial bed material accumulation height in the bubbling fluidized bed reactor. Thus, after the material has been pyrolyzed in the bubbling fluidized bed reactor for a certain period of time, it can enter the conveyor I5 under the action of backmixing and pressure difference.

[0026] The working process of the above-described fluidized gasification-pyrolysis conveying coupled reaction device is as follows: the material enters the bubbling fluidized bed reactor 3 from the screw feeder 6. The fluidizing air from the air chamber 1 enters the bubbling fluidized bed reactor 3 through the air distribution plate 22, and fluidizes the solid material in the bubbling fluidized bed reactor 3, making it in a bubbling fluidized or turbulent fluidized state, and the material completes the initial pyrolysis in the bubbling fluidized bed reactor 3. The bubbling fluidized bed reactor 3 is connected to the conveyor I5 through the transition section 4. The fine particles in the material enter the conveyor I5 section through the transition section 4 under the action of the fluidizing air. The coarse particles in the material enter the conveyor II7 under the action of pressure difference and fluidized bed backmixing. The conveyor I5 is in a pneumatic conveying or rapid fluidization state. The conveyor I5 is connected to the gasifier 8, and the next gasification reaction is completed in the gasifier.

[0027] The working principle of the above-mentioned fluidized gasification-pyrolysis conveying coupled reaction device is as follows: When the device is running, by controlling the air velocity of the fluidizing air introduced into the bubbling fluidized bed reactor 3 and the feed rate of the screw feeder 6, the material is made to be in a bubbling fluidized state and a turbulent fluidized state in the bubbling fluidized bed reactor 3, and under the action of pressure difference and back mixing, it enters the conveyor I5 from the left conveyor II7 of the bubbling fluidized bed reactor 3.

[0028] This fluidized gasification-pyrolysis conveying coupled reaction device controls the amount of solid material entering the conveyor I5 from the bubbling fluidized bed reactor 3 by changing the air velocity of the fluidizing air and the feed rate of the screw feeder 6. Through the combined adjustment of air velocity and feed rate, the gas-solid ratio in the conveyor I5 is maintained within the range of 15-30, and the air velocity of the fluidizing air is maintained between the minimum fluidization velocity and the entrainment velocity to ensure stable conveying without sedimentation. This effectively controls the flow rate and residence time of solid material in the gas-solid reaction device and achieves the organic unity of pyrolysis and conveying, which is more conducive to the subsequent gasification reaction.

[0029] The following is an example of applying the fluidized gasification-pyrolysis conveying coupled reaction device of this invention to a treatment system integrating pyrolysis and conveying of organic solid waste granules. This system includes a wind chamber 1, an air distribution plate 2, a bubbling fluidized bed reactor 3, a transition section 4, a conveyor I5, a screw feeder 6, a conveyor II7, and a gasifier 8. The material outlet of the screw feeder 6 is connected to the bubbling fluidized bed reactor 3 via the conveyor II7. The bubbling fluidized bed reactor 3 is connected to the conveyor I5 via the conveyor II7. Granulated particles (equivalent diameter <30mm) enter the bubbling fluidized bed reactor 3 through the screw feeder 6. Fine particles (equivalent diameter <1000μm) pass through the transition section 4 and enter the conveyor I5 under the action of fluidizing air. Coarse particles (equivalent diameter <2mm) fall directly into the conveyor I5 through the conveyor II7 under the action of pressure difference and backmixing. The bottom of the bubbling fluidized bed reactor 3 is connected to the top of the air chamber 1. The top of the bubbling fluidized bed reactor 3 is connected to the conveyor I5 via a transition section 4. The conveyor I5 is connected to the inlet of the gasifier 8. The bubbling fluidized bed reactor 3 can be operated as a bubbling bed or a turbulent bed. The conveyor I5 can be operated as a pneumatic conveyor or a rapid fluidized bed. The air distribution plate 2 is connected between the bubbling fluidized bed reactor 3 and the air chamber 1. The wall of the air chamber 1 is provided with a fluidizing air inlet. The fluidizing air enters the air chamber 1 through the fluidizing air inlet, and then enters the bubbling fluidized bed reactor 3 through the air distribution plate 2. The pyrolysis temperature of the bubbling fluidized bed reactor 3 is 700-1000℃, the operating temperature of the conveyor I5 and conveyor II7 is 500-800℃, and the operating temperature of the gasifier 8 is 1000-1600℃. The operating pressure of the bubbling fluidized bed reactor 3 is slightly positive pressure (40-60 kPa) or pressurized (~4 MPa).

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that the above embodiments do not limit the scope of protection of this utility model in any way, and all technical solutions obtained by equivalent substitution or other means fall within the scope of protection of this utility model. Parts not covered by this utility model are the same as or can be implemented using existing technology.

Claims

1. A fluidized gasification-pyrolysis transport coupled reaction apparatus, characterized by, The reaction device comprises a wind chamber (1), a wind distribution plate (2), a bubbling fluidized bed reactor (3), a transition section (4), a conveyor I (5), a screw feeder (6), a conveyor II (7) and a gasification furnace (8). The material outlet of the screw feeder (6) is connected with one side end of the bubbling fluidized bed reactor (3), the other side end of the bubbling fluidized bed reactor (3) is connected with the conveyor I (5) through the conveyor II (7), the bottom end of the bubbling fluidized bed reactor (3) is connected with the top end of the wind chamber (1), the wind distribution plate (2) is arranged between the bubbling fluidized bed reactor (3) and the wind chamber (1), the top end of the bubbling fluidized bed reactor (3) is connected with the conveyor I (5) through the transition section (4), and the tail end of the conveyor I (5) is communicated with the inlet of the gasification furnace (8).

2. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The upper part of the bubbling fluidized bed reactor (3) is a dilute phase zone, the lower part is a dense phase zone, and the lower part of the dense phase zone is the wind distribution plate (2).

3. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The bottom wall of the wind chamber (1) is provided with a fluidization wind inlet, and the fluidization wind is one or more of air, oxygen, water vapor and carbon dioxide.

4. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The head end of the conveyor I (5) is connected with the top transition section (4), then the conveyor I (5) is downward along one side of the bubbling fluidized bed reactor (3), and finally the tail end is connected with the inlet of the gasification furnace (8); the outlet end of the conveyor II (7) is connected with the descending section of the conveyor I (5).

5. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The material outlet height of the screw feeder (6) is higher than the inlet height of the conveyor II (7).

6. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The conveyor II (7) is arranged in a downward 5-60° inclination, and the inlet height of the conveyor II (7) is higher than the initial bed material accumulation height in the bubbling fluidized bed reactor.

7. A fluidized gasification-pyrolysis transport coupled reaction apparatus according to claim 1, wherein, The conveyors I (5) and II (7) are pipelines lined with high-temperature wear-resistant coating, and the pipeline diameters of the conveyors I and II are smaller than the pipe diameter of the bubbling fluidized bed reactor.

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