A gas-liquid-solid three-phase circulating fluidized bed cold model experimental device

Abstract

The utility model discloses a kind of gas-liquid-solid three-phase circulating fluidized bed cold model experimental device, belong to fluidized bed experimental device technical field.The experimental device mainly includes liquid inlet, reaction tube, gas inlet, liquid outlet, gas-liquid separator, gas outlet, particle conduit, stock bin, screw feeder, conveying pipe, liquid-solid separator, conveying liquid outlet, filter, conveying liquid inlet, discharge port and discharge valve.Gas in the experimental device is in the form of bubble and moves upward and contacts with liquid-solid phase countercurrent, improves interfacial contact efficiency, liquid-solid phase moves downward, backmixing is small, and spiral feeder can be used to accurately control particle circulation rate;With pressure sensor, capacitance probe, optical fiber probe, high-speed camera and other test instruments, the stability of device can be used to study operating mechanism, reveal multiphase flow distribution in reactor, provide solid data and theoretical support for structure optimization and industrial application of the type reactor.

Description

Technical Field

[0001] This utility model belongs to the technical field of fluidized bed experimental devices, specifically relating to a gas-liquid-solid three-phase circulating fluidized bed cold model experimental device. Background Technology

[0002] Gas-liquid-solid three-phase reactors are widely used in petroleum, energy, biotechnology, chemical engineering, pharmaceuticals, and other fields. Traditional gas-liquid-solid three-phase reactors commonly include stirred tank reactors, bubble columns, and slurry beds. Among these, stirred tank reactors are the most widely used. However, stirred tank reactors require external power equipment, and as a completely mixed flow reactor, they have a high degree of backmixing, which prolongs the reaction time. This makes them unsuitable for continuous reaction processes where the reaction products undergo further transformation. Furthermore, continuous stirred tank reactors have low space utilization, making them unsuitable for large-scale production and presenting challenges in engineering scale-up. In addition, continuous stirred tank reactors require mechanical equipment such as agitators, which place high demands on the strength and sealing of the agitators, limiting their application in high-pressure reactions and high-viscosity systems.

[0003] Compared to stirred tank reactors, bubble column reactors have a simpler structure, require no mechanical stirring, and are more suitable for high-pressure systems. In a bubble column reactor, gas exists in the form of bubbles, which not only increases the gas-liquid interface contact area but also acts as a stirrer, resulting in more uniform liquid-solid mixing and improved heat and mass transfer rates. However, the apparent velocity of the liquid phase in a bubble column reactor is almost zero, leading to severe backmixing. Furthermore, it requires dedicated transfer, separation, and filtration equipment, increasing investment costs. Slurry bed reactors combine the advantages of continuous stirred tank reactors and bubble bed reactors, offering advantages such as simple structure, no need for mechanical rotating equipment, uniform catalyst distribution, and high heat and mass transfer rates. They are currently widely used in heavy oil catalyst hydrogenation, low-carbon hydrocarbon oxidation, and industrial waste gas and wastewater treatment. However, slurry bed reactors still suffer from significant backmixing, have low space utilization, and are not suitable for continuous reactions, thus limiting their application.

[0004] The three reactor types mentioned above, due to their high degree of backmixing, are closer to fully stirred-tank reactors (MSTs). Plug flow reactors, with their absence of backmixing, exhibit significantly better performance and higher reaction efficiency than MSTs. However, both plug flow and stirred-tank reactors differ from the ideal reactor model. In particular, plug flow reactors cannot achieve complete backmixing elimination, and they all exhibit some radial non-uniform distribution. Circulating fluidized bed reactors are a typical plug flow reactor type. Existing research on gas-solid circulating fluidized bed reactors reveals a typical "ring-core" flow structure within the reactor, which may be the main cause of backmixing. Furthermore, in liquid-solid riser reactors, when the liquid velocity is low or high-density particles are used, some particle backmixing still exists in the annular region. This is mainly because both the continuous and dispersed phases operate under an anti-gravity field. To further eliminate backmixing, downward-flowing fluidized bed reactors with gravity have been proposed and a series of studies have been conducted. In downward-flowing fluidized beds, because the flow is entirely with gravity, the radial distribution of particles is more uniform, closer to plug flow. However, existing research has focused on downward-flowing fluidized bed reactors with gas-solid two-phase flow, while research on three-phase circulating fluidized beds, especially those where the liquid and particles flow downwards with gravity while the gas flows upwards, is relatively limited. According to the above description, the flow environment where the liquid and particles flow downwards with gravity while the gas contacts the liquid-solid phase counter-currently in the form of bubbles, exhibits less backmixing compared to traditional circulating fluidized bed reactors where all three phases flow upwards, and possesses unique hydrodynamic characteristics. To study the hydrodynamic characteristics within these three-phase circulating fluidized bed reactors in detail, it is generally necessary to construct a cold-model experimental setup to facilitate observation and measurement of the flow structure of bubbles, particles, and liquid within the reactor, revealing the three-phase transport and mass transfer characteristics within the reactor. Utility Model Content

[0005] Therefore, the purpose of this invention is to provide a cold model experimental device for a gas-liquid-solid three-phase circulating fluidized bed. This device features a simple and compact structure, a complete system, and strong operability. The system can achieve stable catalyst circulation. The experimental device is made of transparent materials such as plexiglass, allowing for direct observation of the flow states of the gas, liquid, and particulate phases within the system. It can be equipped with differential pressure sensors, capacitance probes, fiber optic probes, high-speed cameras, and other related equipment, facilitating systematic research on the stability, flow characteristics, and transport characteristics of the three-phase circulating system, thus laying a solid foundation for the further application of the reactor.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] This invention provides a gas-liquid-solid three-phase circulating fluidized bed cold model experimental device. The experimental device mainly includes a liquid inlet 1, a reaction tube 2, a gas inlet 3, a liquid outlet 4, a gas-liquid separator 5, a gas outlet 6, a particle conduit 7, a storage tank 8, a screw feeder 9, a conveying pipe 10, a liquid-solid separator 11, a conveying liquid outlet 12, a filter 13, a conveying liquid inlet 14, a discharge port 15, and a discharge valve 16. The reaction tube 2, storage tank 8, screw feeder 9, conveying pipe 10, liquid-solid separator 11, particle conduit 7, and gas-liquid separator 5 are connected sequentially. A gas outlet 6 is provided at the top of the gas-liquid separator 5. The particle conduit 7 penetrates the interior of the gas-liquid separator 5 and extends to the top of the reaction tube 2. A liquid inlet 1 is provided at the top of the side wall of the reaction tube 2. The liquid inlet 1 is connected to… A liquid distributor is connected to the bottom of the side wall of the reaction tube 2, and a gas inlet 3 is provided at the bottom of the side wall. The gas inlet 3 is connected to the gas distributor. The bottom of the reaction tube 2 is connected to the top of the storage tank 8. A screw feeder 9 is provided in the middle and lower part of the storage tank 8. A liquid outlet 4 is provided on the side wall of the storage tank 8. A discharge port 15 is provided at the bottom of the storage tank 8. A discharge valve 16 is provided on the connecting pipe of the discharge port 15. The discharge end of the screw feeder 9 extends into the bottom of the side wall of the conveying pipe 10. A conveying liquid inlet 14 is connected to the bottom of the conveying pipe 10. The top of the conveying pipe 10 is connected to the inlet of the liquid-solid separator 11. A conveying liquid outlet 12 is provided on the top axis of the liquid-solid separator 11. A filter 13 is provided on the conveying liquid outlet 12. The bottom of the liquid-solid separator 11 is connected to the inlet of the particle guide tube 7.

[0008] Based on the above technical solution, the gas-liquid-solid three-phase circulating fluidized bed cold model experimental device is made of transparent material, which facilitates the observation and measurement of the fluid dynamic characteristics within the system.

[0009] Based on the above technical solution, the transparent material is further selected from tempered glass, plexiglass, polypropylene, or resin, or a combination of two or more of these materials.

[0010] Based on the above technical solution, the number of particles 7 is further 3 to 20.

[0011] Based on the above technical solution, the liquid distributor is further described as one of the following: a pipe-type liquid distributor, a ring-type liquid distributor, a perforated disc-type liquid distributor, a trough-type liquid distributor, or a jet-type liquid distributor.

[0012] Based on the above technical solution, the gas distributor is further described as one of the following: a wind-cap type gas distributor, a double-row blade type gas distributor, a tubular type gas distributor, a porous tubular type gas distributor, a swirl type gas distributor, or a porous membrane type gas distributor.

[0013] Based on the above technical solution, the diameter of the reaction tube 2 is 20~2000 mm and the height is 0.5~30 m.

[0014] Based on the above technical solution, furthermore, the experimental apparatus uses particles with a particle size of 0.001~5 mm and a particle density of 500-3000 kg / m³. 3 .

[0015] Based on the above technical solution, furthermore, in this utility model, the liquid and particles move downwards along the gravitational field, the backmixing of the liquid and solid phases is small, which is closer to a plug flow reactor. Using a screw feeder, the particle circulation rate and the particle concentration in the reaction tube can be precisely controlled. The operation is simple and the control is flexible.

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

[0017] (1) This utility model has the characteristics of simple structure, easy operation and flexible control. The use of screw feeder can accurately control the particle circulation rate in the system and reduce the height of the device, making it more suitable for laboratory construction.

[0018] (2) In the three-phase circulating fluidized bed cold model experimental device of this utility model, the liquid and particles move downward with the gravity field and come into countercurrent contact with the rising bubbles, which increases the contact efficiency between the gas phase and the liquid-solid phase. At the same time, it can also reduce the backmixing degree of the liquid-solid phase, which can improve the reaction efficiency and the space utilization of the reactor.

[0019] (3) The three-phase circulating fluidized bed cold model experimental device of this utility model is made of transparent materials such as plexiglass, which can directly observe the three-phase flow state and particle circulation in the reactor. With the help of multiphase flow testing instruments such as pressure sensors, capacitance probes, fiber optic probes and high-speed cameras, it can systematically reveal the multiphase flow characteristics in the reactor, providing solid theoretical support for the structural optimization and industrial application of this type of reactor. Attached Figure Description

[0020] To more clearly illustrate the embodiments of this utility model, the accompanying drawings related to the embodiments will be briefly described below.

[0021] Figure 1 This is a schematic diagram of the gas countercurrent liquid-solid downward bed reactor of this utility model. In the figure, 1-liquid inlet, 2-reaction tube, 3-gas inlet, 4-liquid outlet, 5-gas-liquid separator, 6-gas outlet, 7-particle conduit, 8-storage container, 9-screw feeder, 10-transfer pipe, 11-liquid-solid separator, 12-transfer liquid outlet, 13-filter, 14-transfer liquid inlet, 15-discharge port, 16-discharge valve. Detailed Implementation

[0022] The present invention will be described in detail below with reference to the embodiments. However, the implementation of the present invention is not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments can be obtained without creative effort and all fall within the protection scope of the present invention.

[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "front", "back", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Example 1

[0025] This invention provides a gas-liquid-solid three-phase circulating fluidized bed cold model experimental device, the structural schematic diagram of which is shown below. Figure 1As shown, the cold model experimental device mainly includes a liquid inlet 1, a reaction tube 2, a gas inlet 3, a liquid outlet 4, a gas-liquid separator 5, a gas outlet 6, a particle conduit 7, a storage tank 8, a screw feeder 9, a conveying pipe 10, a liquid-solid separator 11, a conveying liquid outlet 12, a filter 13, a conveying liquid inlet 14, a discharge port 15, and a discharge valve 16, etc.; the reaction tube 2, storage tank 8, screw feeder 9, conveying pipe 10, liquid-solid separator 11, particle conduit 7, and gas-liquid separator 5 are connected in sequence, forming an organic, highly coupled structure that enables the cyclic operation of particles and the formation of a highly efficient contact three-phase structure within the reaction tube 2; a gas outlet 6 is provided at the top of the gas-liquid separator 5, and the particle conduit 7 penetrates the interior of the gas-liquid separator 5, extending to the top of the reaction tube 2. There are 10 particle conduits 7, which have the dual functions of conveying particles and ensuring uniform particle distribution; A liquid inlet 1 is provided at the top of the side wall of the reaction tube 2, and the liquid inlet 1 is connected to a porous ring-type liquid distributor. A gas inlet 3 is provided at the bottom of the side wall of the reaction tube 2, and the gas inlet 3 is connected to a microporous gas distributor. The bottom of the reaction tube 2 is connected to the top of the storage tank 8. A screw feeder 9 is provided on the middle and lower cross section of the storage tank 8. A liquid outlet 4 is provided on the side wall of the storage tank 8. A discharge port 15 is provided at the bottom of the storage tank 8. A discharge valve 16 is provided on the connecting pipe of the discharge port 15. The discharge end of the screw feeder 9 extends into the bottom of the side wall of the conveying pipe 10. A conveying liquid inlet 14 is connected to the bottom of the conveying pipe 10. The top of the conveying pipe 10 is connected to the inlet of the liquid-solid separator 11. A conveying liquid outlet 12 is provided on the top axis of the liquid-solid separator 11. A filter 13 is provided on the conveying liquid outlet 12. The bottom of the liquid-solid separator 11 is connected to the inlet of the particle guide tube 7. The three-phase circulating fluidized bed cold model experimental device is made of plexiglass, which facilitates the observation and measurement of the hydrodynamic properties within the system. The device uses a screw feeder 9 to precisely adjust the particle circulation rate and particle concentration within the reaction tube 2, allowing for the study of particle hydrodynamic properties under extremely wide operating conditions. It also reduces the overall height of the device, making it more suitable for laboratory setup. The reaction tube 2 has an inner diameter of 50 mm and a height of 3 m; the particle size is 0.08 mm, and the particle density is 2000 kg / m³. 3 .

[0026] The specific operation process of this experimental device is as follows: The particles stored in the storage tank 8 are pushed to the bottom of the conveying pipe 10 by the screw feeder 9, and move upward along the conveying pipe 10 under the carrying action of the conveying liquid introduced through the conveying liquid inlet 14. Then, they enter the liquid-solid separator 11 for liquid-solid separation. The liquid is filtered by the filter 13 and discharged from the conveying liquid outlet 12. The particles pass through the gas-liquid separator 5 along the particle guide tube 7 and enter the top of the reaction tube 2. Under the combined action of gravity and the main liquid flow introduced through the liquid inlet 1, they move downward along the reaction tube 2. During the movement, they come into countercurrent contact with the gas introduced through the porous gas inlet 3, forming a good gas-liquid-solid contact environment. Subsequently, the liquid and particles enter the top of the storage tank 8 and are separated by sedimentation. The liquid is discharged from the device through the liquid outlet 4, and the particles fall onto the screw feeder 9 for recycling. The gas introduced from the bottom of the reaction tube 2 is separated into gas and liquid in the gas-liquid separator 5 at the top of the reaction tube 2. The gas is discharged from the device through the gas outlet 6.

[0027] In summary, the gas-liquid-solid three-phase circulating fluidized bed cold model experimental device of this invention can achieve stable operation of the device. With the help of testing instruments such as pressure sensors, capacitance probes, fiber optic probes, and high-speed cameras, it can be used to study the stable operation mechanism of the device, reveal the multiphase flow distribution in the reactor, and provide solid data and theoretical support for the structural optimization and industrial application of this type of reactor.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A gas-liquid-solid three-phase circulating fluidized bed cold model experimental device, characterized in that, The experimental apparatus mainly includes a liquid inlet, a reaction tube, a gas inlet, a liquid outlet, a gas-liquid separator, a gas outlet, a particle guide tube, a storage tank, a screw feeder, a conveying pipe, a liquid-solid separator, a conveying liquid outlet, a filter, a conveying liquid inlet, a discharge port, and a discharge valve. The reaction tube, storage tank, screw feeder, conveying pipe, liquid-solid separator, particle guide tube, and gas-liquid separator are connected sequentially. A gas outlet is located at the top of the gas-liquid separator. The particle guide tube penetrates the interior of the gas-liquid separator and extends to the top of the reaction tube. A liquid inlet is located at the top of the side wall of the reaction tube, and the liquid inlet is connected to a liquid distributor. The bottom of the side wall of the reaction tube... The unit is equipped with a gas inlet, which is connected to a gas distributor. The bottom of the reaction tube is connected to the top of the storage tank. A screw feeder is installed in the middle and lower part of the storage tank. A liquid outlet is installed on the side wall of the storage tank. A discharge port is installed at the bottom of the storage tank. A discharge valve is installed on the connecting pipe of the discharge port. The discharge end of the screw feeder extends into the bottom of the side wall of the conveying pipe. A conveying liquid inlet is connected to the bottom of the conveying pipe. The top of the conveying pipe is connected to the inlet of the liquid-solid separator. A conveying liquid outlet is installed on the top axis of the liquid-solid separator. A filter is installed on the conveying liquid outlet. The bottom of the liquid-solid separator is connected to the inlet of the particle guide tube.

2. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The gas-liquid-solid three-phase circulating fluidized bed cold model experimental device is made of transparent material.

3. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 2, characterized in that, The transparent material is one or a combination of two or more of tempered glass, plexiglass, polypropylene, or resin.

4. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The number of granular conduits is 3 to 20.

5. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The liquid distributor is one of the following: a pipe-type liquid distributor, a ring-type liquid distributor, a perforated disc-type liquid distributor, a trough-type liquid distributor, or a jet-type liquid distributor.

6. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The gas distributor is one of the following: a wind-cap type gas distributor, a double-row blade type gas distributor, a tubular type gas distributor, a porous tubular type gas distributor, a swirl type gas distributor, or a porous membrane type gas distributor.

7. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The diameter of the reaction tube is 20~2000 mm and the height is 0.5~30 m.

8. The gas-liquid-solid three-phase circulating fluidized bed cold model experimental apparatus according to claim 1, characterized in that, The experimental apparatus used particles with a diameter of 0.001–5 mm and a particle density of 500–3000 kg / m³. 3 .

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