A multi-circulation fluidized bed reaction apparatus

Abstract

This application relates to the field of material batching, and in particular to a multi-circulating fluidized bed reactor, which includes a circulating fluidization component and a separation component. The circulating fluidization component includes two symmetrically arranged fluidized beds, each with a feed pipe, a discharge pipe, and an outlet pipe at the top, and an air inlet and a return pipe located on one side of the air inlet at the bottom. The fluidized beds contain heat-conducting particles. The separation component is located between the two fluidized beds and includes two symmetrically arranged cyclone separators. The top of each cyclone separator is connected to the outlet pipe of one of the fluidized beds in the circulating fluidization component, and the bottom is connected to the return pipe of the other fluidized bed. The top of each cyclone separator is provided with an air outlet pipe. This application enables materials to circulate and fluidize between multiple fluidized beds, avoiding the problems of uneven particle distribution and short material residence time caused by the difference in terminal velocity between heat-conducting particles and material particles.

Description

Technical Field

[0001] This application relates to the field of chemical reaction equipment, and in particular to a multi-circulation fluidized bed reaction device. Background Technology

[0002] Fluidized bed reactors have wide applications in many industrial fields such as chemical engineering and energy. The development of fluidized bed technology has greatly promoted the progress of related industries. It can enhance heat and mass transfer processes, making chemical reactions more efficient and stable. Through the full contact between the gas and solid phases in the fluidized bed, the reaction rate and product quality can be significantly improved. It has shown great advantages in various processes such as catalytic reactions, drying, and calcination, laying the foundation for large-scale and efficient industrial production.

[0003] When a single-stage fluidized bed is in operation, the difference in terminal velocities between the heat-conducting particles and the material particles leads to uneven particle distribution within the fluidized bed. The material is fed from the top or side of the bed, moves upward with the airflow, and is directly discharged after the reaction. There is no circulation path within the bed, and the contact between the material and the fluidized bed occurs only in a single flow process, which is extremely short. This results in insufficient reaction and makes it difficult to achieve ideal reaction results and product quality. This limits the application of fluidized bed reactors in some industrial production processes with high reaction requirements. Utility Model Content

[0004] The purpose of this application is to overcome the above-mentioned technical problems and provide a multi-circulation fluidized bed reactor.

[0005] A multi-circulation fluidized bed reactor includes:

[0006] A circulating fluidized bed assembly includes two symmetrically arranged fluidized beds. Each fluidized bed has a feed pipe, a discharge pipe, and a discharge pipe at its top, and an air inlet and a return pipe located to one side of the air inlet at its bottom. The fluidized bed contains heat-conducting particles.

[0007] A separation assembly is located between the two fluidized beds. The separation assembly includes two symmetrically arranged cyclone separators. The top of each cyclone separator is connected to the outlet pipe of one of the fluidized beds in the circulating fluidization assembly, and the bottom is connected to the return pipe of the other fluidized bed. Each cyclone separator is provided with an air outlet pipe at its top.

[0008] By adopting the above scheme, the material is fed into the fluidized bed through the feed pipe, and fluidizing gas is blown in through the air inlet at the bottom of the fluidized bed, forming a stable fluidization state within the fluidized bed. The heat-conducting particles come into contact with the material particles, thereby conducting heat to the material particles. Then, the material particles enter the outlet pipe under the action of the fluidizing gas, and then enter the cyclone separator for gas-solid separation. The separated gas is discharged from the air outlet pipe at the top of the cyclone separator. The material after gas-solid separation enters another fluidized bed through the return pipe at the bottom of the cyclone separator to continue the reaction. Then, after the material reacts, it returns to the previous fluidized bed through another cyclone separator, thus circulating fluidization. This avoids the problem of uneven particle distribution and short material residence time in the fluidized bed caused by the difference in terminal velocity between the heat-conducting particles and the material particles.

[0009] In one embodiment, the return pipe extends downward at an angle from the bottom of the cyclone separator.

[0010] By adopting the above scheme, it is ensured that the material particles after gas-solid separation can enter the fluidized bed under the action of gravity.

[0011] In one embodiment, the return pipe includes an outlet and a conveying section. The outlet extends vertically downward from the bottom of the cyclone separator, and the conveying section communicates with the outlet. The conveying section extends obliquely from one end of the outlet away from the cyclone separator toward the bottom of the fluidized bed.

[0012] By adopting the above scheme, the material after gas-solid separation falls from the outlet and enters the conveying section after being accelerated by gravity. This ensures that the material has sufficient power when passing through the conveying section and avoids blockage in the return pipe.

[0013] In one embodiment, the return pipe is provided with an air supply pipe on its side.

[0014] By adopting the above solution, material particles are prevented from adhering to the inner wall of the return pipe and being unable to flow. By setting up an air supply pipe, air is introduced into the return pipe, thereby pushing away the residual material particles in the return pipe.

[0015] In one embodiment, the air supply pipe is located on the side of the return pipe, the air supply pipe is coplanar with the return pipe, and the air supply pipe has the same inclination direction as the outlet.

[0016] By adopting the above scheme, the direction of gas replenishment can be directed towards the extension direction of the outlet, thereby allowing more gas to flow through the gas guide pipe.

[0017] In one embodiment, the fluidized bed includes a gas distributor, a fluidizing section, and an expansion section. The gas inlet is located at the bottom of the gas distributor, the fluidizing section is located at the top of the gas distributor, the heat-conducting particles are located in the fluidizing section, the return pipe is located on the side wall of the fluidizing section, the expansion section is located at the end of the fluidizing section opposite to the gas distributor, and the feed pipe, discharge pipe, and outlet pipe are all located at the top of the expansion section.

[0018] By adopting the above scheme, the gas distributor is used to distribute the gas into uniform small streams of airflow, avoiding local gas velocity that is too high or too low, which would cause some areas of gas not to flow, resulting in insufficient mixing of heat-conducting particles and materials in the fluidization section. The heat-conducting particles and materials are in a fluidized state in the fluidization section, and the expansion section is used to reduce the gas velocity, so that the heat-conducting particles settle.

[0019] In one embodiment, the enlarged section includes a settling section communicating with the fluidization section, the settling section being funnel-shaped with its opening facing upwards.

[0020] By adopting the above scheme, when the airflow flows from the fluidization section to the settling section, the airflow area increases and the gas velocity decreases, thereby causing the heat-conducting particles to settle.

[0021] In one embodiment, the outlet pipe is connected to the side of the discharge pipe, and the enlarged section further includes a guide section connected to the discharge pipe, the guide section being funnel-shaped with its opening facing downwards.

[0022] By adopting the above scheme, the guide section directs the material particles into the outlet pipe, preventing the material particles from getting stuck at the top of the fluidized bed and unable to circulate.

[0023] In one embodiment, an electromagnetic coil is fitted around the outer periphery of the fluidization section, and the surface of the heat-conducting particles is covered with a metal layer.

[0024] By adopting the above scheme, the coil will generate an alternating magnetic field, and the heat-conducting particles will induce eddy currents in the magnetic field. The eddy currents generate heat inside the heat-conducting particles due to resistance, thereby heating the heat-conducting particles. The heat-conducting particles directly transfer heat to the material, avoiding heat conduction lag and improving heating efficiency.

[0025] In one embodiment, the circulating fluidization assembly includes a plurality of fluidized beds arranged in a circumferential array, with a cyclone separator provided between two adjacent fluidized beds. The outlet pipe of one of the two adjacent fluidized beds is connected to the top of the cyclone separator, and the return pipe of the other fluidized bed is connected to the bottom of the cyclone separator.

[0026] By adopting the above scheme, circulating fluidization can be completed even when there are more than two fluidized beds.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. Material is fed into the fluidized bed through the feed pipe. Fluidizing gas is blown in through the air inlet at the bottom of the fluidized bed, forming a stable fluidized state. The heat-conducting particles come into contact with the material particles, thereby conducting heat to the material particles. Then, the material particles enter the outlet pipe under the action of the fluidizing gas, and then enter the cyclone separator for gas-solid separation. The separated gas is discharged from the air outlet pipe at the top of the cyclone separator. After gas-solid separation, the material enters another fluidized bed through the return pipe at the bottom of the cyclone separator to continue the reaction. Then, after the material reacts, it returns to the previous fluidized bed through another cyclone separator, thus circulating fluidization. This avoids the problem of uneven particle distribution and short material residence time in the fluidized bed due to the difference in terminal velocity between the heat-conducting particles and the material particles.

[0029] 2. By setting up an enlarged section, when the airflow flows from the fluidization section to the settling section, the airflow area increases and the gas velocity decreases, thereby causing the heat-conducting particles to settle; the guide section guides the material particles to the outlet pipe, preventing the material particles from getting stuck at the top of the fluidized bed and unable to circulate.

[0030] 3. The coil generates an alternating magnetic field, and the heat-conducting particles will induce eddy currents in the magnetic field. The eddy currents generate heat inside the heat-conducting particles due to resistance, thereby heating the heat-conducting particles. The heat-conducting particles directly transfer heat to the material, avoiding heat conduction lag and improving heating efficiency. Attached Figure Description

[0031] Figure 1 This is an installation schematic diagram of a multi-circulation fluidized bed reactor provided in the first embodiment of this application.

[0032] Figure 2 This is an installation schematic diagram of a multi-circulation fluidized bed reactor provided in the second embodiment of this application.

[0033] Explanation of reference numerals in the attached drawings: 1. Circulating fluidization assembly; 11. Fluidized bed; 111. Gas distributor; 1111. Air inlet; 112. Fluidization section; 1121. Return pipe; 1122. Outlet section; 1123. Conveying section; 1124. Heat-conducting particles; 1125. Air replenishment pipe; 1126. Electromagnetic coil; 113. Expansion section; 1131. Feed pipe; 1132. Discharge pipe; 1133. Outlet pipe; 1134. Settling section; 1135. Guide section; 2. Separation assembly; 21. Cyclone separator; 211. Air outlet pipe. Detailed Implementation

[0034] Therefore, it is necessary to provide a multi-circulation fluidized bed 11 reaction device that can avoid uneven particle distribution and short material residence time in the fluidized bed 11.

[0035] Example 1

[0036] Please see Figure 1 , Figure 1 This is an installation schematic diagram of a multi-circulating fluidized bed reactor provided in the first embodiment of this application. The multi-circulating fluidized bed reactor based on thermally conductive particle induction heating provided in this embodiment includes a circulating fluidization component 1 and a separation component 2. The circulating fluidization component 1 and the separation component 2 cooperate with each other, and the material circulates between the circulating fluidization component 1 and the separation component 2. This avoids the problem of uneven particle distribution and short material residence time in the fluidized bed 11 caused by the difference in terminal velocity between the thermally conductive particles 1124 and the material particles, resulting in a more complete reaction and improved reaction efficiency and product quality.

[0037] The circulating fluidization assembly 1 includes two symmetrically arranged fluidized beds 11. Each fluidized bed 11 has a feed pipe 1131, a discharge pipe 1132, and an outlet pipe 1133 at its top. The outlet pipe 1133 is located on the side of the discharge pipe 1132 and communicates with it. The feed pipe 1131 can adopt a common pipe structure, such as a circular stainless steel pipe, for feeding materials into the fluidized bed 11. The discharge pipe 1132 can also be a circular stainless steel pipe for discharging the reacted materials. The outlet pipe 1133 has a similar structure for guiding the materials to the cyclone separator 21. The fluidized bed 11 has an air inlet 1111 at its bottom and a return pipe 1121 located on one side of the air inlet 1111.

[0038] The air inlet 1111 is generally a circular opening, which can be connected to an air supply pipe via a flange to blow in fluidizing gas and form a stable fluidization. The return pipe 1121 can be made of carbon steel and is used to return the material separated by the cyclone separator 21 back to the fluidized bed 11. The fluidized bed 11 contains heat-conducting particles 1124, which can be ceramic particles covered with a metal layer. The metal layer can be made of metals with good electrical conductivity, such as iron or nickel. Alternatively, the heat-conducting particles 1124 can be metal particles directly, thus possessing good thermal conductivity.

[0039] Each fluidized bed 11 includes a gas distributor 111, a fluidizing section 112, and an expansion section 113. The gas distributor 111 can be a perforated plate structure, such as a stainless steel perforated plate, installed at the bottom of the fluidizing section 112 to uniformly distribute the fluidizing gas blown in through the inlet 1111, creating a stable fluidized environment within the fluidizing section 112. An electromagnetic coil 1126 is fitted around the outer periphery of the fluidizing section 112. The electromagnetic coil 1126 is typically made of copper enameled wire and generates an alternating magnetic field when an alternating current is applied. The fluidizing section 112 is used to contain the heat-conducting particles 1124 and the material, allowing them to fully contact and react under the action of the fluidizing gas. The return pipe 1121 is located on the side wall of the fluidizing section 112.

[0040] The expansion section 113 is located at the end of the fluidizing section 112 away from the gas distributor 111. The feed pipe 1131, discharge pipe 1132, and outlet pipe 1133 are all located at the top of the expansion section 113. The expansion section 113 includes a funnel-shaped settling section 1134 connected to the fluidizing section 112. The opening of the settling section 1134 faces upward. This funnel-shaped structure can be made of carbon steel. When the airflow rises from the fluidizing section 112 and enters the settling section 1134, the airflow area increases and the flow velocity decreases, thereby causing the heat-conducting particles 1124 to settle down. The expansion section 113 also includes a funnel-shaped guide section 1135 connected to the discharge pipe 1132. The guide section 1135 faces downward and is connected to the outlet pipe 1133. It is also made of carbon steel. It can guide the material particles into the discharge pipe 1132 and the outlet pipe 1133, preventing the material from getting stuck at the top of the fluidized bed 11.

[0041] The separation assembly 2 is located between the circulating fluidization assemblies 1 and includes at least two symmetrically arranged cyclone separators 21. The top of each cyclone separator 21 is connected to the outlet pipe 1133 of one of the fluidized beds 11, and the bottom is connected to the return pipe 1121 of the other fluidized bed 11. The cyclone separators 21 can be made of carbon steel or stainless steel, and their working principle is based on gas-solid separation using centrifugal force. The top of the cyclone separator 21 is equipped with an outlet pipe 211, which is generally a circular pipe used to discharge the separated gas.

[0042] The return pipe 1121 extends downwards at an angle from the bottom of the cyclone separator 21. This inclined structure ensures that the material particles after gas-solid separation can enter the fluidized bed 11 under the action of gravity. The return pipe 1121 includes an outlet section 1122 and a conveying section 1123. The outlet section 1122 extends vertically downwards from the bottom of the cyclone separator 21, and the conveying section 1123 communicates with the outlet section 1122 and extends at an angle towards the bottom of the fluidized bed 11. Both the outlet section 1122 and the conveying section 1123 can be made of carbon steel pipes. After being accelerated by gravity in the outlet section 1122, the material enters the conveying section 1123, ensuring sufficient power and preventing blockage of the material in the return pipe 1121. The side of the return pipe 1121 is provided with an air supply pipe 1125. The air supply pipe 1125 can be a stainless steel pipe with a smaller diameter. It is inclined in the same direction as the outlet 1122 and is coplanar with the return pipe 1121. By venting air into the return pipe 1121, the residual material particles in the return pipe 1121 are pushed to prevent the material particles from adhering to the inner wall of the return pipe 1121 and being unable to flow.

[0043] The various components of the circulating fluidization assembly 1 are combined. Material is fed into the feed pipe 1131, fluidizing gas is blown in through the air inlet 1111, and the gas distributor 111 ensures uniform gas distribution. In the fluidization section 112, the heat-conducting particles 1124 and the material fully contact and react in a fluidized environment. The expansion section 113 facilitates the settling of the heat-conducting particles 1124 and guides the material flow. These components cooperate to ensure stable reaction of the material within the fluidized bed 11. The separation assembly 2 works in conjunction with the circulating fluidization assembly 1 to perform gas-solid separation of the reacted material. The separated material re-enters the fluidized bed 11 for further reaction through the return pipe 1121, forming a highly efficient material circulation and reaction system.

[0044] The implementation principle of this embodiment is as follows: First, metal particles are added to the two fluidized beds 11, and preheated fluidizing gas is introduced to form a stable fluidization in the fluidized beds 11. Then, the electromagnetic coil 1126 is energized, and the current magnitude and frequency are adjusted to heat the internal metal particles to the required temperature. The material particles are fed into the two fluidized beds 11 through the feed inlet. The material and metal particles are mixed evenly under the action of the airflow. The mixed raw material particles are rapidly heated to reach the target temperature. A mixture of preheated process reaction gas and carrier gas is introduced. The raw material particles react in a fluidized and uniform state and continuously rise from the reaction section to the expansion section 113. After passing through the conveying section, they enter the cyclone separator 21. The metal particles settle under the action of gravity after passing through the expansion section 113 in the fluidized section 112. Two cyclone separators 21 respectively draw in solid particles from one fluidized bed 11 and introduce them into another fluidized bed 11 for circulating fluidization. After the reaction time is reached, the outlet pipe 1133 and the inlet pipe valve between the fluidized bed 11 and the cyclone separator 21 are closed to blow the solid particles inside the fluidized bed 11 out of the fluidized bed 11 and obtain the finished product.

[0045] Example 2

[0046] Please see Figure 2 , Figure 2This is a schematic diagram of the installation of a multi-circulating fluidized bed reactor according to the second embodiment of this application. The structure of this embodiment is basically the same as the above embodiments, except that the circulating fluidization component 1 includes multiple fluidized beds 11 arranged in a circular array, with a cyclone separator 21 between two adjacent fluidized beds 11. The basic structure of the fluidized beds 11 and the cyclone separator 21 is similar to that of Embodiment 1, but the layout is different. The multiple fluidized beds 11 arranged in a circular array can utilize space more effectively, increasing the material circulation path and the number of reactions. For example, four, six, or even more fluidized beds 11 can be set, and each fluidized bed 11 still has a feed pipe 1131, a discharge pipe 1132, an outlet pipe 1133, an air inlet 1111, a return pipe 1121, and other structures. Two adjacent fluidized beds 11 have their outlet pipe 1133 connected to the top of the cyclone separator 21, and their return pipe 1121 connected to the bottom of the cyclone separator 21. The material continuously circulates and reacts in this structure.

[0047] The implementation principle of this embodiment is as follows: The combination of multiple fluidized beds 11 arranged in a circular array and cyclone separators 21 further increases the number of material circulations and residence time, resulting in a more complete reaction. The multi-circulation fluidized bed 11 reactor can process more materials simultaneously. This layout improves the space utilization and processing capacity of the device, making it particularly suitable for large-scale industrial production. Compared to the symmetrical arrangement in Embodiment 1, the circular array arrangement better adapts to different production sites and needs. By increasing the number of fluidized beds 11, the processing scale of the device can be flexibly adjusted, providing more choices and possibilities for industrial production, and further optimizing and improving the existing technology.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multi-circulating fluidized bed reactor, characterized in that, include: A circulating fluidized bed assembly (1) includes two symmetrically arranged fluidized beds (11). Each fluidized bed (11) has a feed pipe (1131), a discharge pipe (1132), and a discharge pipe (1133) at its top. The fluidized bed (11) also has an air inlet (1111) at its bottom and a return pipe (1121) located on one side of the air inlet (1111). The fluidized bed (11) contains heat-conducting particles (1124). The separation component (2) is located between the two fluidized beds (11). The separation component (2) includes two symmetrically arranged cyclone separators (21). The top of each cyclone separator (21) is connected to the outlet pipe (1133) of one of the fluidized beds (11) in the circulating fluidization component (1), and the bottom is connected to the return pipe (1121) of the other fluidized bed (11). Each cyclone separator (21) is provided with an air outlet pipe (211) at the top.

2. The multi-circulation fluidized bed reactor according to claim 1, characterized in that: The return pipe (1121) extends downward at an angle from the bottom of the cyclone separator (21).

3. The multi-circulation fluidized bed reactor according to claim 2, characterized in that: The return pipe (1121) includes an outlet (1122) and a conveying section (1123). The outlet (1122) extends vertically downward from the bottom of the cyclone separator (21). The conveying section (1123) is connected to the outlet (1122). The conveying section (1123) extends obliquely from the end of the outlet (1122) away from the cyclone separator (21) toward the bottom of the fluidized bed (11).

4. The multi-circulation fluidized bed reactor according to claim 3, characterized in that: The return pipe (1121) is provided with an air supply pipe (1125) on its side.

5. A multi-circulation fluidized bed reactor according to claim 4, characterized in that: The air supply pipe (1125) is located on the side of the return pipe (1121). The air supply pipe (1125) and the return pipe (1121) are coplanar. The air supply pipe (1125) and the outlet (1122) have the same inclination direction.

6. The multi-circulation fluidized bed reactor according to claim 1, characterized in that: The fluidized bed (11) includes a gas distributor (111), a fluidizing section (112), and an enlargement section (113). The air inlet (1111) is located at the bottom of the gas distributor (111), the fluidizing section (112) is located at the top of the gas distributor (111), the heat-conducting particles (1124) are located in the fluidizing section (112), the return pipe (1121) is located on the side wall of the fluidizing section (112), the enlargement section (113) is located at the end of the fluidizing section (112) away from the gas distributor (111), and the feed pipe (1131), the discharge pipe (1132), and the outlet pipe (1133) are all located at the top of the enlargement section (113).

7. A multi-circulation fluidized bed reactor according to claim 6, characterized in that: The enlarged section (113) includes a settling section (1134) connected to the fluidized section (112), the settling section (1134) being funnel-shaped with its opening facing upwards.

8. A multi-circulation fluidized bed reactor according to claim 7, characterized in that: The outlet pipe (1133) is connected to the side of the discharge pipe (1132), and the enlarged section (113) also includes a guide section (1135) connected to the discharge pipe (1132), the guide section (1135) being funnel-shaped with the opening facing downwards.

9. A multi-circulation fluidized bed reactor according to claim 6, characterized in that: An electromagnetic coil (1126) is fitted on the outer periphery of the fluidization section (112), and a metal layer is covered on the surface of the heat-conducting particles (1124).

10. A multi-circulation fluidized bed reactor according to claim 1, characterized in that: The circulating fluidization assembly (1) includes multiple fluidized beds (11) arranged in a circumferential array. A cyclone separator (21) is provided between two adjacent fluidized beds (11). The outlet pipe (1133) of one of the two adjacent fluidized beds (11) is connected to the top of the cyclone separator (21), and the return pipe (1121) of the other fluidized bed (11) is connected to the bottom of the cyclone separator (21).

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