A method for designing a segmented silicone monomer fluidized bed gas plenum

Abstract

This invention discloses a design method for a segmented organosilicon monomer fluidized bed gas booster pipe, including (1) designing the performance parameters of the second cylinder; (2) establishing a simplified three-dimensional model of the second cylinder; (3) importing the simplified model established in step 2 into software for processing; (4) performing numerical simulation calculations on the simplified model in step 3; (5) obtaining data based on the simulation results; (6) plotting a change curve based on the data; (7) changing the vertical plane angle β and repeating steps (1)-(6) to obtain the optimal vertical plane angle β; (8) changing the horizontal plane angle α and repeating the process several times to obtain the optimal horizontal plane angle α; (9) determining the installation position of the gas booster pipe based on the optimal horizontal plane angle α and vertical plane angle β. This achieves the goal of satisfying material rising while avoiding severe wear at the discharge port.

Description

Technical Field

[0001] This invention relates to the field of fluidized bed reactor technology, and specifically to a design method for a segmented organosilicon monomer fluidized bed gas booster pipe. Background Technology

[0002] During the reaction, the materials inside the fluidized bed are mainly distributed from bottom to top according to particle size. The completed product leaves through the discharge port, but this process causes significant wear on the discharge port, resulting in economic losses and safety hazards. Therefore, how to mitigate wear on the feed port is a technical problem that urgently needs to be solved in the existing technology. Summary of the Invention

[0003] This invention addresses the problems existing in the prior art by proposing a design method for a segmented organosilicon monomer fluidized bed gas booster pipe.

[0004] The technical solution adopted in this invention is: a design method for a segmented organosilicon monomer fluidized bed gas booster pipe, comprising:

[0005] (1) Design the performance parameters of the second cylinder, including the inner diameter and height of the cylinder, the inner diameter and depth of the gas booster pipe, the horizontal plane angle α, and the vertical plane angle β;

[0006] (2) Establish a simplified three-dimensional model of the second cylinder: Based on the performance parameters obtained in step 1, use SolidWorks software to draw the three-dimensional model of the second cylinder in step 1, and then retain the cylinder and gas pressurization pipe to obtain a simplified model of the three-dimensional model of the second cylinder.

[0007] (3) Import the simplified model established in step 2 into ANSYS Workbench, seal and fill the cylinder inlet and outlet and the gas pressurization pipe, and after filling, use unstructured tetrahedral mesh to mesh the simplified model, name the inlet and outlet boundaries, check the mesh for errors in General, and modify the size scale to mm.

[0008] (4) Import the simplified model in step 3 into the Workbench Fluent software for numerical simulation calculation; where the gravity is set to 9.81 m / s2 in general settings, the model is set to the standard k-epsilon RNG model, and the liquid-solid two-phase flow equation includes the continuity equation and momentum equation of turbulent motion; create the bottom inlet of the second cylinder as the first jet source, the jet source type is surface, inert particles, set the inlet velocity of the bottom inlet, the gas booster pipe is the second jet source, the jet source type is surface, inert particles, use surface normal direction for jetting, set the inlet velocity of the gas booster pipe, the diameter of the flowing particles, and the total flow rate;

[0009] (5) Based on the simulation results, obtain the particle motion trajectory of the second cylinder, the velocity and pressure distribution of the central region section, and the velocity and pressure distribution of the airflow confluence region section in the simplified model;

[0010] (6) Record the velocity and pressure data of the central region section ZY and the airflow confluence region section ZX and plot the change curves;

[0011] (7) Repeat steps (1)-(6) several times, change the value of the vertical plane angle β in step (1), obtain several new optimization models, obtain the change curves of several new optimization models, compare all the change curves, and obtain the optimal vertical plane angle β.

[0012] (8) Repeat steps (1)-(6) several times, change the horizontal plane angle α in step (1), keep the optimal vertical plane angle β and other parameters unchanged, and obtain the optimal horizontal plane angle α;

[0013] (9) Determine the angle between the gas booster pipe installation section and the vertical section on the second cylinder according to the optimal horizontal plane angle α, and determine the tilt angle of the gas booster pipe according to the optimal vertical plane angle β.

[0014] Based on the above scheme, as a preferred option, the transport equation of the RNG k-epsilon model is:

[0015]

[0016]

[0017]

[0018] In the formula , ,

[0019] This represents the generation of turbulent kinetic energy caused by the average velocity gradient.

[0020] Turbulent kinetic energy generated by buoyancy

[0021] This represents the contribution of wave expansion to the total dissipation rate in compressible turbulence.

[0022] fluid density

[0023] rate of dissipation of turbulent pulsating kinetic energy

[0024] and They are and The reciprocal of the effective Prandtl number

[0025] and It is a user-defined source item.

[0026] Based on the above scheme, as a preferred option, the continuity equation for turbulent motion is:

[0027]

[0028] The momentum equation for turbulent motion is:

[0029]

[0030] δ i3 The Kroneck symbol, with a value of 0 or 1;

[0031] u - velocity; - Average speed statistics; i, j - Number of operations;

[0032] u i ′-Pulse value;

[0033] x i -i coordinate position in the direction of x; j The coordinate position in the -j direction;

[0034] σ ij Represents the total average stress tensor;

[0035] v represents the fluid velocity, in m / s;

[0036] t represents time, in seconds;

[0037] τ ij Represents the average flow viscous stress, in N;

[0038] τ ij ′ represents the additional stress due to turbulence, in N;

[0039] ρ represents the reference density relative to the reference temperature T0, in kg / m³. 3 ;

[0040] T is taken as the average flow temperature or boundary layer temperature, k;

[0041] g is the acceleration due to gravity in the vertical direction, m / s² 2 ;

[0042] β represents the coefficient of thermal expansion of the liquid; This represents the average value of T.

[0043] Based on the above scheme, as a preferred option, in step (1), the inner diameter of the second cylinder is 3500mm and the height is 12000mm, the inner diameter of the gas booster pipe is 650mm, the depth is 1500mm, the horizontal plane angle α is 45°, and the vertical plane angle β is 45°.

[0044] Based on the above scheme, as a preferred option, in step (4), the flow velocity of the bottom inlet is 2m / s, the flow velocity of the gas booster pipe inlet is 10m / s, the diameter of the flowing particles is 100μm, and the total flow rate is 1e-20kg / s.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] To address the issue of uneven material distribution within the second cylinder area, an inclined gas booster pipe is used. This uses swirling flow to drive the material to flow in a specific pattern, allowing for a more complete reaction.

[0047] When the material enters the first cylinder from the second cylinder with the airflow, it has a high velocity due to the supplementary gas and pressure, resulting in significant wear on the heat exchange tubes. This invention addresses this by using two sets of gas booster pipes: the lower set provides supplementary gas and pressure to the material, while the upper set controls its velocity, thus ensuring the material rises while preventing severe wear at the outlet. Furthermore, both sets of gas booster pipes are controlled in real-time by pressure gauges, allowing for control of reactant quality.

[0048] The gas booster pipe is installed at both the upper and lower ends of the second cylinder. To meet actual production needs, a certain size of variable diameter section area is required for installation. Simulation verification is used to confirm the optimal horizontal plane angle α and the optimal vertical plane angle β of the gas booster pipe, thereby determining the optimal inclination angle for the installation position. Furthermore, the variable diameter section is only slightly larger than the diameter of the gas booster pipe to minimize its impact on the flow field. While ensuring structural strength, the variable diameter section of the second cylinder is manufactured according to the optimal horizontal plane angle α. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the second cylinder;

[0050] Figure 2 It is a simplified model of the second cylinder;

[0051] Figure 3 It is the trajectory of particle motion;

[0052] Figure 4 This is a velocity contour map of the ZY plane;

[0053] Figure 5 This is a ZY plane pressure contour map;

[0054] Figure 6 This is a velocity contour map of the ZX plane;

[0055] Figure 7 This is a ZX plane pressure contour map;

[0056] Figure 8 It is the velocity variation curve in the ZY plane;

[0057] Figure 9 This is the ZY plane pressure variation curve;

[0058] Figure 10 It is the velocity variation curve in the ZX plane;

[0059] Figure 11 This is the ZX plane pressure variation curve;

[0060] Figure 12 These are velocity contour maps of the ZY plane at different β angles;

[0061] Figure 13 These are ZY plane pressure contour maps at different β angles;

[0062] Figure 14 These are velocity contour maps of the ZX plane at different β angles;

[0063] Figure 15 These are ZX plane pressure contour maps at different β angles;

[0064] Figure 16 This is a schematic diagram of a segmented organosilicon monomer fluidized bed reactor. Detailed Implementation

[0065] The present invention will be further illustrated by the following examples, but the scope of the present invention is not limited thereto.

[0066] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0067] like Figure 1-16 As shown, the fluidized bed includes a first cylinder 1 and a second cylinder 2. The second cylinder includes a straight section 22 and gas booster pipe installation sections 21 located at both ends of the straight section. The gas booster pipe 3 is fixedly installed in the gas booster pipe installation section.

[0068] In an organosilicon fluidized bed reactor, the material enters the second cylinder and stops rising. At this point, the material's potential energy (energy from gravity and the gas flow) reaches equilibrium, resulting in a relatively static state. In this scenario, gas booster pipes are installed in two rows on the upper and lower walls of the cylinder. By injecting high-temperature gas, the potential energy of the material is altered, creating two swirling streams with the same direction of rotation. The gas velocity and injection angle are used to control the material flow primarily within the second cylinder. When the reaction time is sufficient and the particle size is small enough, the reactant velocity is lower than that of the original reactor, reducing wear on the outlet and achieving controllable material quality.

[0069] Principle: The energy difference between the upper and lower airflows needs to be compensated by the material reaction reducing gravitational potential energy. However, gravitational potential energy decreases as the reaction time increases. Therefore, the reaction time of the material in the second cylinder is controlled by the gas booster pipe.

[0070] Case 1: Energy of downward airflow + gravitational potential energy of material = energy of upward airflow (material is relatively stationary in the reactor)

[0071] Scenario 2: The energy of the downward airflow plus the gravitational potential energy of the material is less than the energy of the upward airflow (the gravitational potential energy of the material decreases with increasing reaction time, while the energy of the downward and upward airflows remains constant, therefore the material will begin to rise).

[0072] The main reaction formulas are as follows:

[0073]

[0074] Chemical reaction rate equation:

[0075]

[0076] [X] represents the activity of a given reactant X, usually expressed in moles per liter (mol / L).

[0077] k represents the rate constant of this reaction.

[0078] The exponents x and y represent the reaction order, which depends on the reaction mechanism.

[0079] The general form of the above rate equation is the differential form of the rate equation. It can be derived from the reaction mechanism and clearly shows the effect of concentration on the reaction rate, which is convenient for theoretical analysis. Integrating it yields the integral form of the rate equation, which is the functional relationship between reactant / product concentration [X] and time t.

[0080] The optimized design method for gas booster pipes includes the following steps:

[0081] (1) Obtain the performance parameters of the second cylinder, including the inner diameter and height of the cylinder, the inner diameter and depth of the gas booster pipe, the horizontal plane angle α, and the vertical plane angle β. Among them, the inner diameter of the cylinder is 3500mm, the height is 12000mm, the inner diameter of the gas booster pipe is 650mm, the depth is 1500mm, the horizontal plane angle α is 45°, and the vertical plane angle β is 45°.

[0082] (2) Establish a simplified 3D model of the second cylinder: Based on the performance parameters obtained in step 1, use SolidWorks software to draw the 3D model of the second cylinder from step 1. Then, retain the cylinder and the gas pressurization pipe to obtain a simplified model of the 3D model of the second cylinder, such as... Figure 2 As shown, the material enters from the bottom of the cylinder and exits from the top. The airflow enters the cylinder through two rows of gas booster pipes. The gas booster pipes are relatively independent and arranged in a circular array along the cylinder wall. The upper and lower rows are mirror images of each other, and the spray angles and directions of rotation are opposite.

[0083] (3) Import the simplified model established in step 2 into ANSYS Workbench, seal and fill the cylinder inlet and outlet and the gas pressurization pipe, and after filling, use unstructured tetrahedral mesh to mesh the simplified model, name the inlet and outlet boundaries, check the mesh for errors in General, and modify the size scale to mm.

[0084] (4) Import the simplified model in step 3 into the Workbench Fluent software for numerical simulation calculation; the gravity is set to 9.81 m / s2 in general settings, and the model is set to the standard k-epsilon RNG model. The liquid-solid two-phase flow equation includes the continuity equation and momentum equation of turbulent motion; create the bottom inlet as jet source 1, the jet source type is surface, inert particles, the inlet velocity is 2 m / s, and the gas booster pipe (inlet1~16) is jet source 2, the jet source type is surface, inert particles, using surface normal direction for jetting, the inlet velocity is 10 m / s, the diameter of the flowing particles is 100 μm, and the total flow rate is 1e-20 kg / s;

[0085] The cylinder is primarily cylindrical, therefore the flow within it is mainly swirling. The RNG k-epsilon model performs better than the standard k-epsilon model in terms of shear flow, vortices and separated flow, and swirling corrections. The transport equations for the RNG k-epsilon model are:

[0086]

[0087]

[0088]

[0089] In the formula , , ,

[0090] This represents the generation of turbulent kinetic energy caused by the average velocity gradient.

[0091] Turbulent kinetic energy generated by buoyancy

[0092] This represents the contribution of wave expansion to the total dissipation rate in compressible turbulence.

[0093] fluid density

[0094] rate of dissipation of turbulent pulsating kinetic energy

[0095] and They are and The reciprocal of the effective Prandtl number

[0096] and It is a user-defined source item.

[0097] The continuity equation for turbulent motion is:

[0098]

[0099] The momentum equation for turbulent motion is:

[0100]

[0101] δ i3 The Kroneck symbol, with a value of 0 or 1;

[0102] u - speed; - Average speed statistics; i, j - Number of operations;

[0103] u i ′-Pulse value;

[0104] x i -i coordinate position in the direction of x; j The coordinate position in the -j direction;

[0105] σ ij Represents the total average stress tensor;

[0106] v represents the fluid velocity, in m / s;

[0107] t represents time, in seconds;

[0108] τ ij Represents the average flow viscous stress, in N;

[0109] τ ij ′ represents the additional stress due to turbulence, in N;

[0110] ρ represents the reference density relative to the reference temperature T0, in kg / m³. 3 ;

[0111] T is taken as the average flow temperature or boundary layer temperature, k;

[0112] g is the acceleration due to gravity in the vertical direction, m / s² 2 ;

[0113] β represents the coefficient of thermal expansion of the liquid; This represents the average value of T;

[0114] (5) Based on the simulation results, obtain the particle motion trajectory of the second cylinder, the velocity and pressure distribution of the central region section, and the velocity and pressure distribution of the airflow confluence region section in the simplified model.

[0115] Movement of material particles inside the cylinder:

[0116] The volume fraction of the material is very small, so its motion characteristics are basically determined by the distribution of the flow field. Under the influence of the converging effect of the two swirling flows in the upper and lower rows of gas booster pipes, the material forms a regular spiral motion within the cylinder, such as... Figure 3 As shown.

[0117] Pressure and velocity distribution at the ZY section in the central region of the cylinder:

[0118] By extracting the cross-section of the central region (the cross-section at the very center of the cylinder, shown in the software as the ZY section), the velocity and pressure contour diagrams in the ZY plane inside the cylinder are obtained as follows: Figure 4 , 5 According to the velocity and pressure simulation analysis results in the figure, the gas velocity in the gas booster pipe accessory in the upper part of the second cylinder is too high, resulting in a large low-pressure area.

[0119] Velocity and pressure distribution at section ZX in the airflow confluence region

[0120] The cross-section of the airflow confluence region (the cross-section of the upper gas booster pipe, shown as section ZX in the software) is extracted to obtain the velocity and pressure cloud diagrams in the ZX plane inside the cylinder, as shown below. Figure 6 , 7 Based on the velocity and pressure simulation analysis results in the figure, it can be concluded that the swirling effect in the airflow confluence area is too strong, and the velocity and pressure distribution is uneven.

[0121] (6) Record the velocity and pressure data of the central region section ZY and the airflow confluence region section ZX for subsequent plotting of change curves;

[0122] (7) Perform structural optimization on the simplified model in step 2 to obtain a new optimized model:

[0123] Among them, the structural optimization mainly lies in the included angle β of the vertical plane. The value range of β is limited by the outer diameter of the gas booster pipe and the inner diameter of the second cylinder, and is approximately between 0° and 45°.

[0124] By taking different values ​​of the vertical plane angle β, and repeating steps 1 to 6, the velocity and pressure cloud of the central region section ZY of different optimization models can be obtained. Figure 12 , 13 The velocity and pressure clouds of the cross section ZX in the airflow confluence region. Figure 14 , 15 Plot the velocity and pressure curves of the ZY cross section in the central region of different optimization models. Figure 8 , 9 Velocity and pressure curves of cross section ZX in the airflow confluence region Figure 10 , 11 ;

[0125] By comparing the velocity and pressure change curves of all models, the optimal vertical plane angle β is obtained. This requires satisfying the conditions of uniform pressure distribution in the central region section ZY and a gradual velocity distribution in the airflow confluence region section ZX. This invention verifies five β angles: 25°, 30°, 35°, 40°, and 45°. It is found that a β angle of 25° best satisfies the condition of a gradual velocity distribution in the airflow confluence region section ZX, followed by 35°. Similarly, a β angle of 35° best satisfies the condition of uniform pressure distribution in the central region section ZY, followed by 25°. Therefore, subsequent work can focus on the optimal vertical plane angle β being between 25° and 35°.

[0126] (8) Through analysis Figure 8 , 9 10, 11. After finding the optimal vertical plane angle β, repeat steps 1 to 6. The structural optimization is done on the horizontal plane angle α. The value of α is limited by the outer diameter of the gas booster pipe and the inner diameter of the second cylinder, and is approximately between 0° and 60°. The optimal horizontal plane angle α is obtained.

[0127] (9) Determine the angle between the gas booster pipe installation section and the vertical section on the second cylinder based on the optimal horizontal plane angle α, 11. and thus design the cylinder diameter-changing section. The installation section does not appear in the simplified model and is mainly represented by the optimal horizontal plane angle α. However, in actual production, the installation position of the gas booster pipe needs to be considered, so a diameter-changing section will inevitably appear. By finding the optimal injection angle of the gas booster pipe through the above steps, the diameter-changing angle of the installation section can be determined. The installation section should be as small as possible to avoid having a large impact on the flow field. The tilt angle of the gas booster pipe is determined based on the optimal vertical plane angle β.

[0128] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A design method for a segmented organosilicon monomer fluidized bed gas booster pipe, characterized in that, include: (1) Design the performance parameters of the second cylinder, including the inner diameter and height of the cylinder, the inner diameter and depth of the gas booster pipe, the horizontal plane angle α, and the vertical plane angle β; (2) Establish a simplified three-dimensional model of the second cylinder: Based on the performance parameters obtained in step 1, use SolidWorks software to draw the three-dimensional model of the second cylinder in step 1, and then retain the cylinder and gas pressurization pipe to obtain a simplified model of the three-dimensional model of the second cylinder. (3) Import the simplified model established in step 2 into ANSYS Workbench, seal and fill the cylinder inlet and outlet and the gas pressurization pipe, and after filling, use unstructured tetrahedral mesh to mesh the simplified model, name the inlet and outlet boundaries, check the mesh for errors in General, and modify the size scale to mm. (4) Import the simplified model in step 3 into the Workbench Fluent software for numerical simulation calculation; where the gravity is set to 9.81 m / s2 in general settings, the model is set to the standard k-epsilon RNG model, and the liquid-solid two-phase flow equation includes the continuity equation and momentum equation of turbulent motion; create the bottom inlet of the second cylinder as the first jet source, the jet source type is surface, inert particles, set the inlet velocity of the bottom inlet, the gas booster pipe is the second jet source, the jet source type is surface, inert particles, use surface normal direction for jetting, set the inlet velocity of the gas booster pipe, the diameter of the flowing particles, and the total flow rate; (5) Based on the simulation results, obtain the particle motion trajectory of the second cylinder, the velocity and pressure distribution of the central region section, and the velocity and pressure distribution of the airflow confluence region section in the simplified model; (6) Record the velocity and pressure data of the central region section ZY and the airflow confluence region section ZX and plot the change curves; (7) Repeat steps (1)-(6) several times, change the value of the vertical plane angle β in step (1), obtain several new optimization models, obtain the change curves of several new optimization models, compare all the change curves, and obtain the optimal vertical plane angle β. (8) Repeat steps (1)-(6) several times, change the horizontal plane angle α in step (1), keep the optimal vertical plane angle β and other parameters unchanged, and obtain the optimal horizontal plane angle α; (9) Determine the angle between the gas booster pipe installation section and the vertical section on the second cylinder according to the optimal horizontal plane angle α, and determine the tilt angle of the gas booster pipe according to the optimal vertical plane angle β.

2. The design method of the segmented organosilicon monomer fluidized bed gas booster pipe as described in claim 1, characterized in that, The transport equation for the RNG k-epsilon model is: In the formula , , , This represents the generation of turbulent kinetic energy caused by the average velocity gradient. Turbulent kinetic energy generated by buoyancy This represents the contribution of wave expansion to the total dissipation rate in compressible turbulence. fluid density rate of dissipation of turbulent pulsating kinetic energy and They are and The reciprocal of the effective Prandtl number and It is a user-defined source item.

3. The design method of the segmented organosilicon monomer fluidized bed gas booster pipe as described in claim 1, characterized in that, The continuity equation for turbulent motion is: The momentum equation for turbulent motion is: δ i3 The Kronecker symbol, with a value of 0 or 1; u - velocity; - Average speed statistics; i, j - Number of operations; u i ′-Pulse value; x i -i coordinate position in the direction of x; j The coordinate position in the -j direction; σ ij Represents the total average stress tensor; v represents the fluid velocity, in m / s; t represents time, in seconds; τ ij Represents the average flow viscous stress, in N; τ ij ′ represents the additional stress due to turbulence, in N; ρ represents the reference density relative to the reference temperature T0, in kg / m³. 3 ; T is taken as the average flow temperature or boundary layer temperature, k; g is the acceleration due to gravity in the vertical direction, m / s² 2 ; β represents the coefficient of thermal expansion of the liquid; This represents the average value of T.

4. The design method of the segmented organosilicon monomer fluidized bed gas booster pipe as described in claim 1, characterized in that, In step (1), the inner diameter of the second cylinder is 3500mm and the height is 12000mm. The inner diameter of the gas booster pipe is 650mm, the depth is 1500mm, the horizontal plane angle α is 45°, and the vertical plane angle β is 45°.

5. The design method of the segmented organosilicon monomer fluidized bed gas booster pipe as described in claim 1, characterized in that, In step (4), the flow velocity at the bottom inlet is 2 m / s, the flow velocity at the gas booster pipe inlet is 10 m / s, and the diameter of the flowing particles is 100 μm.

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