Reaction process device and feeding device and parameter optimization method thereof

Abstract

The invention provides a reaction process device and a feeding device and a parameter optimization method thereof. Wherein the feeding device comprises a feeding pipeline, an annular pipeline and at least two spiral nozzles; the feeding pipeline comprises a main feeding branch pipe and at least two branch flow dividing branch pipes, the main feeding branch pipe is communicated with the annular pipeline through the branch flow dividing branch pipes, and the spiral nozzles are distributed on the annular pipeline in a scattered mode. According to the invention, uniform material flow distribution can be ensured, the dispersion uniformity of the material liquid on the cross section of the reaction kettle is enhanced, and scaling caused by excessive accumulation of local materials in the reaction kettle is prevented. The smooth flow channel design of the spiral nozzle and the high liquid speed in the channel can reduce the scaling and blocking probability of the feeding pipeline to a certain extent.

Description

Technical Field

[0001] This disclosure relates to the field of chemical equipment technology, and in particular to a reaction process apparatus and its feeding device, and a parameter optimization method. Background Technology

[0002] Reactor and other reaction process equipment are important industrial devices, typically consisting of a vessel body, stirring system, heat transfer system, feed / discharge port, monitoring instruments, etc. They achieve uniform mixing of reactants and heat and mass transfer through mechanical stirring, and are widely used in industrial processes such as hydrolysis, neutralization, crystallization, distillation, storage, hydrogenation, hydrocarbonation, polymerization, condensation, heating and mixing, and isothermal reactions.

[0003] In processes using reactors, liquid-liquid mixing reactions are common. These reactions often involve adding materials through a single orifice at the top of the reactor, which can lead to poor dispersion of the materials entering the reactor. Excessive material accumulation near the baffles on the liquid surface can cause over-reaction due to localized high concentrations, exacerbating scaling on the reactor walls. This negatively impacts product quality and increases the difficulty of cleaning the reactor. Simultaneously, the low flow rate in the drip feed pipe also makes it prone to clogging, disrupting the normal operation of the production process. Summary of the Invention

[0004] The technical problem to be solved by this disclosure is to overcome the defects of the feeding method of the reaction process device in the prior art, which leads to uneven material dispersion, easy blockage of the feeding pipe, local over-reaction and scaling. The disclosure provides a reaction process device and its feeding device, as well as a parameter optimization method.

[0005] This disclosure solves the above-mentioned technical problems through the following technical solution:

[0006] In a first aspect, a feeding device is provided, comprising: a feeding pipeline, an annular pipeline, and at least two spiral nozzles; the feeding pipeline includes a main feeding branch pipe and at least two branch pipes for diversion, the main feeding branch pipe being connected to the annular pipeline through the branch pipes, and the spiral nozzles being distributed along the annular pipeline. Preferably, the feeding device is applied to a reaction process apparatus with a single feed inlet.

[0007] Optionally, the number of spiral nozzles is determined based on the spray range of the spiral nozzles and the cross-section of the reactor included in the reaction process apparatus.

[0008] Optionally, the spiral nozzles are arranged at equal intervals on the annular pipe;

[0009] And / or, each branch pipe is installed at equal intervals on the annular pipeline;

[0010] And / or, the number of the spiral nozzles is four;

[0011] And / or, the number of the branch pipes is 2.

[0012] Optionally, the feed pipeline further includes a feed reducer, the first end of which is fixed to the feed inlet at the top of the reactor included in the reaction process device, and the second end of which is connected to the main feed branch pipe; wherein the inner diameter of the first end is larger than the inner diameter of the second end.

[0013] Optionally, the feeding device further includes a pulse generator; the pulse generator is disposed inside the main feeding branch pipe;

[0014] Optionally, the feeding device further includes a pulse generator and an external feeding pipe, wherein the pulse generator is disposed inside the external feeding pipe and the external feeding pipe is disposed outside the reactor; the external feeding pipe is connected to the main feeding branch pipe, or, if the feeding pipeline includes a feeding reducer, the external feeding pipe is connected to the feeding reducer.

[0015] Optionally, the pulse generator generates pressure pulses at a fixed frequency; the fixed frequency can be an empirical value or can be obtained by simulation calculation of the reactor with the built-in feeding device.

[0016] And / or, the pulse intensity of the pulse generator is in the range of [0.1 MPa, 0.5 MPa]; the pulse intensity can be an empirical value or can be obtained by simulation calculation of the reactor with the built-in feeding device.

[0017] And / or, the feeding device further includes a pressure regulating valve, which is located inside the main feed branch pipe, or, if the feeding device includes an external feed pipe, the pressure regulating valve is located inside the external feed pipe. Preferably, a flow sensor is also provided inside the external feed pipe, and the pressure regulating valve is located downstream of the external fluid source and upstream of the flow sensor.

[0018] Optionally, the feeding device further includes a flow sensor, a pressure sensor, and a controller, wherein the controller is electrically connected to the flow sensor, the pressure sensor, and the pulse generator respectively; the flow sensor and the pressure sensor are arranged inside the main feed branch pipe or the external feed pipe, and the flow sensor and the pressure sensor are located downstream of the pressure regulating valve and upstream of the pulse generator;

[0019] The controller is used to adjust the pulse frequency of the pulse generator according to the flow data detected by the flow sensor and the pressure data detected by the pressure sensor until the flow data and the pressure data meet the preset conditions.

[0020] In a second aspect, a reaction process apparatus is provided, comprising a reaction vessel and a feeding device as described in any one of the first aspects;

[0021] The reactor is provided with a feed inlet at the top, the feed device is located inside the reactor, and the feed pipeline is connected to the feed inlet.

[0022] Optionally, the feed device includes a branch pipe, annular pipe, spiral nozzle, and main feed branch pipe, all of which are located inside the reactor; and if the feed pipe does not include a feed reducer, the reactor inlet is connected to the main feed branch pipe; if the feed pipe includes a feed reducer, the reactor inlet is connected to the feed reducer.

[0023] Thirdly, a parameter optimization method for a feeding device is provided, the parameter optimization method being used to optimize the structural parameters of the feeding device described in the first aspect; the parameter optimization method includes the following steps:

[0024] The flow field calculation results of the reactor with the built-in feeding device were obtained through numerical simulation;

[0025] The structural parameters of the feeding device are optimized based on the flow field calculation results; wherein the structural parameters include at least one of the following: the number of branch pipes, the number of spiral nozzles, the angle of the spiral nozzles, the layout of the spiral nozzles, the layout of the branch pipes, the size of the main feed branch pipe, the size of the branch pipes, and the size of the annular pipeline.

[0026] Optionally, the structural parameters of the feeding device are optimized based on the flow field calculation results, including:

[0027] The kurtosis value of the prepolymer concentration in the cross section is determined based on the flow field calculation results.

[0028] Optimize the structural parameters of the feeding device based on the kurtosis value of the prepolymer concentration in the cross section;

[0029] The formula for calculating the kurtosis value of the prepolymer concentration in the cross section is as follows:

[0030]

[0031] Where n represents the number of cross-sectional data points, i represents the i-th data point, and c i This represents the concentration value of the i-th data point. SD represents the sample concentration mean, and SD represents the sample concentration standard deviation.

[0032] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this disclosure.

[0033] The positive and progressive effects of this disclosure are as follows: the annular pipeline in this disclosure plays a role in redistributing the material flow to ensure that the material flow into each spiral nozzle is evenly distributed; the multiple spiral nozzles arranged on the annular pipeline can further enhance the uniformity of material dispersion in the cross section of the reactor by spraying a larger droplet range on the basis of multi-point feeding, preventing excessive accumulation of material in the reactor and scaling; the unobstructed flow channel design of the spiral nozzles and the high liquid velocity inside the channel can also reduce the probability of scaling and blockage in the feed pipeline to a certain extent. Attached Figure Description

[0034] Figure 1 A schematic diagram of a feeding device without a pulse generator is provided as an exemplary embodiment of this disclosure;

[0035] Figure 2 A schematic diagram of a feeding device with a pulse generator is provided as an exemplary embodiment of this disclosure;

[0036] Figure 3 A schematic diagram of the structure of a pulse generator included in a feeding device, provided as an exemplary embodiment of this disclosure;

[0037] Figure 4 A flowchart illustrating the determination of the pulse frequency of a pulse generator by a feeding device, provided as an exemplary embodiment of this disclosure;

[0038] Figure 5 A schematic diagram of a reaction process apparatus provided for an exemplary embodiment of this disclosure;

[0039] Figure 6 A flowchart illustrating a parameter optimization method for a feeding device provided as an exemplary embodiment of this disclosure;

[0040] Figure 7 A basic flow chart of a UDF for monitoring the kurtosis value of prepolymer concentration distribution in a reaction process apparatus provided as an exemplary embodiment of this disclosure;

[0041] Figure 8 A comparison diagram of the cross-sectional prepolymer concentration peaks of a reaction process apparatus provided for an exemplary embodiment of this disclosure;

[0042] Figure 9 A schematic diagram of the dimensions of a feeding device used in a reaction process apparatus provided for an exemplary embodiment of this disclosure;

[0043] Figure 10 A schematic diagram showing the installation position of the spiral nozzle and the spray coverage area of ​​the material liquid in a feeding device, provided as an exemplary embodiment of this disclosure;

[0044] Figure 11aA cross-sectional velocity contour plot of a stirred tank provided as an exemplary embodiment of this disclosure;

[0045] Figure 11b A cross-sectional velocity vector diagram of a stirred tank provided for an exemplary embodiment of this disclosure;

[0046] Figure 11c An axial velocity cloud diagram of a stirred tank provided as an exemplary embodiment of this disclosure;

[0047] Figure 11d A volume fraction cloud map of a mixed liquid phase in a stirred tank provided as an exemplary embodiment of this disclosure;

[0048] Figure 11e A schematic diagram of cross-sectional velocity distribution at different axial heights inside a stirred tank, provided as an exemplary embodiment of this disclosure;

[0049] Figure 11f A schematic diagram of prepolymer concentration distribution at a cross-sectional position h = 3500 mm (h = 0 mm at the bottom of the vessel) in a stirred tank, provided for the prior art;

[0050] Figure 11g for Figure 11f Schematic diagram of the prepolymer dispersion process at the mid-section;

[0051] Figure 11h A schematic diagram of the prepolymer concentration distribution at a cross-sectional position h = 3500 mm (h = 0 mm at the bottom of the vessel) in a stirred tank with a feeding device provided in an exemplary embodiment of the present disclosure;

[0052] Figure 11i for Figure 11h Schematic diagram of the prepolymer dispersion process at the mid-section. Detailed Implementation

[0053] The present disclosure is further illustrated below by way of embodiments, but the present disclosure is not limited to the scope of the embodiments described herein.

[0054] The prefixes such as "first" and "second" used in this disclosure are merely for distinguishing different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes used to distinguish descriptive objects in this disclosure does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and should not be construed as an unnecessary limitation. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0055] Figure 1This is a schematic diagram of a feeding device provided as an exemplary embodiment of the present disclosure. This feeding device can be applied to a reaction process apparatus with a single feed inlet. See also... Figure 1 The feeding device includes: a feeding pipeline, an annular pipeline 12, and at least two spiral nozzles 13; the feeding pipeline includes a main feeding branch pipe 111 and at least two branch pipes 112, the main feeding branch pipe 111 is connected to the annular pipeline 12 through the branch pipes 112, and each spiral nozzle 13 is distributed on the annular pipeline 12.

[0056] The annular pipe 12 serves to redistribute the material flow, ensuring uniform distribution of liquid (material) flow into each spiral nozzle 13. Multiple spiral nozzles 13 arranged on the annular pipe 12, based on multi-point feeding, further enhance the uniformity of material dispersion across the reactor cross-section through a larger droplet spray range, preventing excessive material accumulation in localized areas of the reactor, thus avoiding over-reaction or scaling. Furthermore, the unobstructed flow channel design of the spiral nozzles 13 and the high liquid velocity within the channels also reduce the likelihood of scaling and blockage in the feed pipe. The high flow velocity within the spiral nozzle channels is attributed to the constraint and guidance of fluid flow by its structural design: the small-diameter inlet causes the flow velocity to increase proportionally with area contraction, and the spiral guiding structure ensures continuous fluid flow along the tank wall without dead zones, guaranteeing uniform and efficient flow velocity throughout the pipe section, and promoting efficient conversion of pressure energy into kinetic energy.

[0057] It should be noted that the annular pipe 12 can be a circular ring or an elliptical ring, and the size and shape of the annular pipe 12 can be adapted to the reaction vessel included in the actual application reaction process device.

[0058] The number of branch pipes 112 and spiral nozzles 13 can be set according to actual needs, and is not limited to the two branch pipes and four spiral nozzles shown in the figure. Preferably, each branch pipe 112 and each spiral nozzle 13 are symmetrically arranged with respect to a cross section of the annular pipe 12. The angle of the spiral nozzle 13 and the connection method between the spiral nozzle and the annular pipe can also be adjusted according to actual needs.

[0059] The feeding device provided in this embodiment does not require changing the existing pipe arrangement on the top of the reactor included in the reaction process device. The feeding device is placed inside the reactor, and the feeding pipe of the feeding device is fixed to the top of the reactor through the original feeding port on the top of the reactor. No modification to the reactor is required, and the original feeding port can still be used for feeding.

[0060] In this embodiment, the uniformity of material dispersion within the reactor is improved, avoiding over-reaction and scaling caused by some materials remaining in localized areas for too long. This embodiment effectively addresses scaling issues at the feeding pipe locations that may arise from submersion feeding, material splashing within the reactor, or material crystallization within the pipes.

[0061] In one embodiment, the number of spiral nozzles 13 is determined based on the spray range of the spiral nozzles 13 and the cross-section of the reactor contained in the reaction process apparatus. Here, in order to avoid corrosion of the stirring shaft and scaling of the reactor wall, the spray range of the spiral nozzles 13 should cover a larger cross-section of the reactor without excluding the stirring shaft and the reactor wall.

[0062] In one embodiment, the number of spiral nozzles 13 and the number of branch pipes 112 are determined by simulation calculation on a reactor equipped with the feeding device of this embodiment. The specific implementation of the simulation calculation is described below. Preferably, simulation determines that the number of spiral nozzles 13 is 4 and the number of branch pipes 112 is 2, resulting in better feeding performance.

[0063] In one embodiment, each branch pipe 112 is equally spaced on the annular pipe 12 to improve the uniformity of the material in the annular pipe 12.

[0064] In one embodiment, the spiral nozzles 13 are arranged at equal intervals on the annular pipe 12 to further improve the uniformity of material flow distribution of each spiral nozzle 13.

[0065] In one embodiment, the feed pipeline further includes a feed reducer 113, the first end of which is fixed to the feed inlet at the top of the reactor included in the reaction process device, and the second end of which is connected to the main feed branch pipe 111; wherein the inner diameter of the first end is larger than the inner diameter of the second end.

[0066] In this embodiment, the feeding smoothness can be improved and the risk of blockage can be reduced by setting a feed reducer.

[0067] In one embodiment, see Figure 2 The feeding device also includes a pulse generator 14, which is located inside the main feed branch pipe 111. The pulse generator 14 may be electromagnetically driven, but is not limited to being driven by an electromagnetic drive. During the feeding process, the pulse generator 14 is driven to generate pressure pulses, causing the material at the outlet of the spiral nozzle 13 to be intermittently sprayed, thereby enhancing the atomization effect of the spiral nozzle 13 and the anti-clogging performance of the pipeline.

[0068] In one embodiment, the feeding device further includes an external feed pipe (not shown in the figure), and the pulse generator 14 is disposed inside the external feed pipe. The external feed pipe is disposed outside the reactor; the external feed pipe is connected to the main feed branch pipe, or, if the feed pipeline includes a feed reducer, the external feed pipe is connected to the feed reducer.

[0069] In this embodiment, the pulse generator is placed inside the external feed pipe, which facilitates the adjustment, maintenance, and replacement of the pulse generator.

[0070] Figure 3This is a schematic diagram of the structure of a pulse generator 14 shown in an exemplary embodiment of the present disclosure. The pulse generator 14 mainly includes a junction box 1, an electromagnet 2, a movable push rod 3, a moving iron core spring 4, a movable iron core 5, a movable push rod assembly 6, a moving iron core spring 7, a piston 8, a piston seal 9, and a valve body 10. The working principle of the pulse generator 14 is as follows: when the electromagnet is energized, it generates electromagnetic attraction, lifting the piston, thus forming a passage in the main feed branch pipe 111 to allow fluid (material) to flow through; when the power is off, the moving iron core spring force presses the piston tightly, closing the passage and cutting off the fluid flow. By controlling the opening and closing frequency of the pulse generator 14, intermittent pulse jets are formed.

[0071] In one embodiment, the pulse generator 14 generates pressure pulses at a fixed frequency. The fixed frequency can be an empirical value or can be obtained through simulation calculations of a reactor with a built-in feeding device. Preferably, the fixed frequency is 10-20 pulses per minute.

[0072] In one embodiment, the pulse intensity of the pulse generator 14 ranges from [0.1 MPa to 0.5 MPa]. The pulse intensity can be an empirical value or obtained through simulation calculations on a reactor with a built-in feeding device.

[0073] In one embodiment, the feeding device further includes a pressure regulating valve located inside the main feed branch pipe.

[0074] In one embodiment, when the feeding device includes an external feed pipe, the pressure regulating valve is located inside the external feed pipe. Preferably, a flow sensor is also provided inside the external feed pipe, and the pressure regulating valve is located downstream of the external fluid source and upstream of the flow sensor. The pressure regulating valve enables a stable feed output to the pulse generator 14.

[0075] In one embodiment, the feeding device further includes a flow sensor (not shown), a pressure sensor (not shown), and a controller (not shown). The controller is electrically connected to the flow sensor, the pressure sensor, and the pulse generator 14, respectively. The flow sensor and the pressure sensor are arranged inside the main feed branch pipe, and are located downstream of the pressure regulating valve and upstream of the pulse generator. The controller is used to adjust the pulse frequency of the pulse generator 14 according to the flow data detected by the flow sensor and the pressure data detected by the pressure sensor. The pulse frequency of the pulse generator 14 can be adjusted, but is not limited to, through a PID control algorithm, until the flow data and pressure data meet preset conditions. The preset conditions can be set according to actual needs.

[0076] In one embodiment, to facilitate adjustment, maintenance, and replacement of the flow sensor and pressure sensor, when the feeding device includes an external feed pipe, the flow sensor and pressure sensor are arranged inside the external feed pipe and located downstream of the pressure regulating valve and upstream of the pulse generator. The control logic of the controller is similar to that in the above embodiment and will not be described again here.

[0077] In other implementations, the flow sensor, pressure sensor, pressure regulating valve, and pulse generator can be partially located inside the external feed pipe and partially located inside the main feed branch pipe. For example, the pressure regulating valve, flow sensor, and pressure sensor are located inside the external feed pipe, while the pulse generator is located inside the main feed branch pipe; or, the pressure regulating valve is located inside the external feed pipe, while the flow sensor, pressure sensor, and pulse generator are located inside the main feed branch pipe.

[0078] The specific working process is described below: (1) Low-pressure liquid supply: The liquid phase (material) is pressurized to the set pressure (e.g., 0.1MPa-0.5MPa) by a low-pressure pump, and then stably output to the inlet of the pulse generator through a pressure regulating valve; (2) Pulse generation and nozzle atomization: The controller drives the pulse generator to open and close rapidly, cutting the continuous liquid flow (material) into discrete pulse flow. The pulse flow enters the spiral nozzle to form atomized droplets. (3) The flow sensor monitors the instantaneous flow rate (flow data), the pressure sensor monitors the pipeline pressure fluctuation (pressure data), and the controller uses a PID algorithm to dynamically adjust the pulse frequency; for details, see Figure 4 The controller determines whether the pressure and flow rate meet the preset conditions. If the condition is met, the current pulse frequency is maintained. If the condition is not met, the pulse frequency is reset and the process returns to the step of generating pulses at the reset pulse frequency.

[0079] In this embodiment, the low-pressure liquid supply and low-pressure design can reduce energy consumption by 30% to 50%, which is beneficial to energy conservation and environmental protection.

[0080] In this embodiment, the pulse frequency of the pulse generator 14 is dynamically adjusted according to the actual state of the feed to adapt to fluctuations in the working conditions, ensure the stability of the feed, and facilitate precise and controllable process.

[0081] See Figure 5 This disclosure also provides a reaction process apparatus, which includes a reaction vessel 51 and a feeding device 52 provided in any of the above embodiments. The reaction vessel has a feeding port at its top, the feeding device is located inside the reaction vessel, and a feeding pipeline is connected to the feeding port. The feeding pipeline can be fixedly connected to the feeding port, or it can be detachably connected to the feeding port via a snap-fit ​​or other mechanical structure; this disclosure does not impose any particular limitation on this aspect.

[0082] Specifically, the feeding device, including the branch pipe, annular pipe, spiral nozzle, and main feed branch pipe, is located inside the reactor. When the feed pipe does not include a feed reducer, the reactor inlet is connected to the main feed branch pipe; when the feed pipe includes a feed reducer, the reactor inlet is connected to the feed reducer. The main feed branch pipe or feed reducer can be fixedly connected to the inlet, or it can be detachably connected to the inlet via a snap-fit ​​or other mechanical structure; this embodiment does not impose any particular limitation on this.

[0083] The reaction process apparatus in this embodiment can be industrial equipment used for industrial processes such as hydrolysis, neutralization, crystallization, distillation, storage, hydrogenation, hydrocarbonation, polymerization, condensation, heating and mixing, and isothermal reaction. For example, the reaction process apparatus can be a stirred tank.

[0084] This embodiment uses the reaction process of isocyanate prepolymer and amino resin as an example for illustration. The isocyanate prepolymer reacts with the amino resin in the reactor by being added.

[0085] This disclosure also provides a parameter optimization method for a feeding device. This parameter optimization method is used to optimize the structural parameters of the feeding device provided in any of the above embodiments. The structural parameters may include, but are not limited to, the number of branch pipes, the number of spiral nozzles, the angle of the spiral nozzles, the layout of the spiral nozzles, the layout of the branch pipes, the size of the main feed branch pipe, the size of the branch pipes, the size of the annular pipe, the connection method between the spiral nozzles and the annular pipe, the pulse frequency of the pulse generator, and the pulse intensity of the pulse generator.

[0086] The parameter optimization method includes the following steps: S1, obtaining the flow field calculation results of the reactor with the built-in feeding device through numerical simulation; S2, optimizing the structural parameters of the feeding device based on the flow field calculation results.

[0087] See Figure 6 The parameter optimization method specifically includes the following steps:

[0088] Step 601: Obtain the flow field calculation results of the reactor with built-in feeding device through numerical simulation.

[0089] In this embodiment, the CFD (Computational Fluid Dynamics) numerical simulation method is used for simulation calculation.

[0090] Step 602: Determine the kurtosis value of the prepolymer concentration in the cross section based on the flow field calculation results.

[0091] The formula for calculating the kurtosis value of the cross-sectional prepolymer concentration is as follows:

[0092]

[0093] Where n represents the number of cross-sectional data points of the reactor, i represents the i-th data point, and c i This represents the concentration value of the i-th data point. SD represents the sample concentration mean, and SD represents the sample concentration standard deviation.

[0094] Step 603: Optimize the structural parameters of the feeding device based on the peak concentration value of the prepolymer in the cross section.

[0095] The kurtosis value of the prepolymer concentration in this cross-section is a statistical measure describing the steepness of the distribution of all values ​​in the overall data. In this embodiment, the kurtosis value of the prepolymer concentration in the cross-section is used to quantitatively represent the high concentration of local material liquid. This statistic needs to be compared with a normal distribution. A kurtosis of 0 indicates that the overall data distribution is of the same steepness as the normal distribution; a kurtosis greater than 0 indicates that the overall data distribution is steeper than the normal distribution, with a sharp peak; a kurtosis less than 0 indicates that the overall data distribution is flatter than the normal distribution, with a flat peak. The larger the absolute value of the kurtosis, the greater the difference in the steepness of its distribution from the normal distribution.

[0096] In the embodiments of this disclosure, a corresponding "user-defined function" (UDF) can be used to monitor the kurtosis value of the prepolymer concentration in the cross section, thereby enabling real-time judgment of whether there are local high concentration regions of prepolymer during the calculation process. This facilitates a direct comparison of the prepolymer dispersion effect under different operating conditions. The basic process of this UDF is as follows: Figure 7 As shown (where sum is the first-order sum of volume fractions; sum2 is the sum of squares, used to calculate variance; sum4 is the fourth-order sum, used to calculate kurtosis; count is the number of cells that meet the criteria).

[0097] See Figure 8 As can be seen, in the stirred tank of the feeding device of this embodiment, the change trend of the prepolymer concentration peak in the cross section is gentle and the absolute value is small, indicating that there are almost no local high values ​​of prepolymer concentration at the cross section.

[0098] The following section uses a stirred tank reactor as an example to illustrate the process of parameter optimization:

[0099] S11. Measure the specific dimensions of the mixing vessel, stirring paddle, baffle, and prepolymer feed pipe; the diameter of the mixing vessel inlet is 51mm, the outward extension length is 150mm, and the distance between the inlet and the vertical center axis of the mixing vessel is 800mm. Based on the prepolymer spraying range of the nozzle (spraying angle: 90°), determine the height of the spiral nozzle above the liquid level in the mixing vessel to be 750mm; determine the height of the feed pipe of the feeding device based on the distance between the liquid level and the top of the vessel. Figure 9As shown, this specifically includes the distance H1 between the top of the reactor and the bottom of the prepolymer feed reducer, the height H2 between the bottom of the prepolymer feed reducer and the plane containing the center of the branch pipe, the height H3 between the center plane of the branch pipe and the center plane of the annular pipe, and the height H4 between the center plane of the annular pipe and the top of the spiral nozzle; the inner diameter of the feed device pipe is determined to be 10mm. In other implementations, the main feed pipe, branch pipe, and annular pipe can be set with different inner diameters according to actual needs, that is, the inner diameters of the main feed pipe, branch pipe, and annular pipe have certain dimensional differences. Figure 10 The diagram shows the installation location of the spiral nozzles and the spray coverage of the prepolymer: the diameter of the annular pipe is 1600mm, and four nozzles are evenly installed on the annular pipe at equal intervals. The diameter of the circular coverage area of ​​the spray produced by the nozzles is 1500mm. Based on the determined device dimensions, a three-dimensional model of the stirred tank including the feeding device was created using Space Claim software, and the inlet / outlet, stirring paddle surface, wall surface, and rotation interface were named.

[0100] S12. Use the Fluent Meshing module to generate an unstructured tetrahedral mesh for the stirred tank model, locally refine the surfaces of the impeller, baffle, and distributor, add boundary layers, and verify the mesh independence.

[0101] S13, a. Import the mesh into Fluent software, determine the mesh unit (mm) and mass (minimum orthogonal mass greater than 0.15), select pressure-based steady state as the solver, and set the gravity direction to the positive direction along the Z-axis; add the in-vessel liquid phase and prepolymer in Material, and change the viscosity and density to the physical property parameters under actual industrial operating conditions;

[0102] b. Selection and Setting of Multiphase Flow Model: Euler-Euler models for handling multiphase flows include volume fraction (VOF) models, mixing models, and Euler models. The VOF model is primarily used to simulate non-overlapping multiphase fluid flows. It achieves this by solving a shared momentum equation and tracking the volume fraction of each phase. This is a surface tracking technique that requires little memory, has a wide range of applications, and is simple and effective. The embodiments of this disclosure focus on the phase distribution of the prepolymer and the state of the interphase interfaces. Without considering interphase interference, the multiphase flow model can be set to the VOF model, with three Eulerian phases: air, the liquid phase in the reactor, and the prepolymer. The governing equations for the VOF model are as follows:

[0103] Volume fraction equation:

[0104]

[0105] In the formula: α qρ represents the volume fraction of the q-th phase, indicating the proportion of the control volume occupied by the q-th phase; q The density of phase q is kg / m³. 3 ;v q Let m be the velocity of phase q, in m / s; pq For mass transfer from phase p to phase q, m qp To transfer mass from phase q to phase p, by default, the source terms in the equations... It is zero.

[0106] Momentum equation:

[0107]

[0108] In the formula: ρ and μ are the density and viscosity of the fluid, respectively. The velocity is expressed in m / s. This is the velocity transpose matrix; The acceleration due to gravity is m / s². 2 ; For volume force, N; The pressure difference is expressed in Pa.

[0109] c. Turbulence model selection and settings:

[0110] Fluent provides turbulence models including: single-equation (Spalart-Allmaras) models, two-equation models (standard k-ε model, renormalization group k-ε model, and realizable k-ε model), Reynolds stress models, and large eddy simulations. Among these, the k-ε model, especially the standard k-ε model, is widely used in engineering. The embodiments disclosed herein employ the standard k-ε model as the turbulence model, and the turbulent kinetic energy and dissipation rate equations are calculated according to the following formulas:

[0111] Transport equation for turbulent kinetic energy k:

[0112]

[0113] Transport equation for turbulent dissipation rate ε:

[0114]

[0115] In the above equation, ρ and μ are the density and viscosity of the fluid, respectively, and u i x represents the average velocity component. i and x j G represents spatial coordinates, t represents time, and G represents spatial coordinates. k G represents the turbulent kinetic energy generation term caused by the average velocity gradient. b Y represents the turbulent kinetic energy generation term caused by buoyancy. MC represents the contribution of the wave expansion of compressible turbulence to the overall dissipation rate; ε1 and C ε2 C represents the proportionality constants for the generating and dissipating terms in the ε equation, with default values ​​of 1.44 and 1.92, respectively; ε3 The coefficient representing the influence of buoyancy on the generation of ε, with a value ranging from 0 to 1; σ k and σ ε μ are the Prandtl numbers for k and ε, respectively, with default values ​​of 1 and 1.3. t The turbulent viscosity coefficient: μ t =ρC μ (k 2 / ε), C μ This represents the correlation constant between turbulent viscosity and k and ε, with a default value of 0.09.

[0116] d. Setting boundary conditions:

[0117] The rotational domain was defined using the multi-reference frame motion method, with the rotational speed set to 73 rev / min. The inlet type was set to velocity inlet, and the inlet velocity was set to 0 (this calculation is divided into two stages: the first stage involves stirring the liquid phase inside the vessel, and the second stage involves adding prepolymer dropwise to the vessel when the stirring has reached a stable state). The outlet type was set to pressure outlet, and the gauge pressure was set to 0 Pa. A mesh interface was established between the dynamic and static domains. The remaining boundary types were set to wall. The initial liquid phase region region0 was established using the coordinate range input function in cell registers.

[0118] e. Setting the solution method:

[0119] Pressure-velocity coupled solution algorithm: Coupled; Mesh: Least Squares CellBased scheme; Pressure: Presto! scheme; Momentum: Second-order upwind scheme; Volume fraction: Compressive scheme; Turbulence parameters: First-order upwind scheme.

[0120] f. Initialization settings:

[0121] The standard initialization method is used to first initialize the entire region: the volume fraction of air in the reactor is 1, and the volume fractions of liquid phase and prepolymer in the reactor are both 0; then local initialization is performed: the volume fraction of liquid phase in the initial liquid phase region region0 in the reactor is set to 1.

[0122] S14. Calculate and solve the example, and monitor the torque value of the stirring paddle and the velocity distribution inside the vessel. When the torque value reaches a stable state and the velocity distribution inside the vessel remains basically unchanged, it can be determined that the convergence state has been reached. At this time, the steady-state multiphase flow field is obtained, and the example and data are saved.

[0123] S15. Set the prepolymer inlet velocity to 0.09 m / s, the turbulence intensity to 7.1164%, the hydraulic diameter to 51 mm, and the prepolymer inlet volume fraction to 1. Change to transient settings to track the flow trajectory of the prepolymer in the reactor.

[0124] The turbulence intensity is calculated by the following formula:

[0125] Reynolds number Re: In the formula, D is the pipe diameter, u is the average flow velocity of the pipe cross section, ρ is the fluid density, and μ is the dynamic viscosity.

[0126] Turbulence Intensity I:

[0127] S16. After the solution is completed, import the calculation results into the CFD-post module for post-processing to obtain the velocity distribution of the fluid inside the reactor and the volume fraction distribution of the prepolymer.

[0128] The velocity distribution of the fluid and the volume fraction distribution of the prepolymer within the reactor characterize the fluid motion within the reactor, and this motion pattern can be used to judge the effectiveness of the feeding device. If the effect is unsatisfactory, the structural parameters of the feeding device are iteratively adjusted until the effect reaches the ideal value.

[0129] In this embodiment, CFD numerical calculation technology is applied to the field of chemical engineering. Fluent software is used to numerically simulate the velocity distribution and phase distribution in the stirred tank. This avoids the high cost and implementation difficulties of experimental techniques in large-scale stirred reaction devices. Moreover, it allows for a more intuitive observation of the dispersion process of the prepolymer in the tank, providing technical support for the design and optimization of the feed pipeline structure of industrial stirred tanks.

[0130] In other implementations, S11' replaces S11, and S12' replaces S12. S11': Measure the specific dimensions of the stirred tank, impeller, and baffle; based on the determined device dimensions, use Space Claim software to create a 3D model of the stirred tank under the current operating conditions, and name the inlet / outlet, impeller surface, wall, and rotation interface; S12': Use the Fluent Meshing module to divide the stirred tank model into unstructured tetrahedral meshes, locally refine the impeller and baffle surfaces and add boundary layers, and verify the mesh's independence; the remaining steps (S13'-S16') are consistent with the corresponding steps (S13-S16) described above.

[0131] In one embodiment, the rationality and feasibility of the structural optimization of the feeding device are also verified during the parameter optimization process, providing reference and theoretical support for similar processes such as liquid-liquid mixing reactions.

[0132] The fluid simulation process will be further explained below:

[0133] S21. Referring to the existing structure and dimensions of the stirred tank device, a three-dimensional model of the stirred tank is established in Space claim software. The main structure of the stirred tank includes the stirred tank body, feeding device, baffle, and stirring paddle. The main fluid domain includes the fluid volume inside the tank excluding the stirring paddle and four baffles.

[0134] S22. Mesh generation and independence verification;

[0135] S23. Import the mesh into the fluent module of ANSYS software, and determine the material parameters, physical model, turbulence model, boundary conditions, and calculation methods;

[0136] S24. Perform numerical simulation calculations on the example and save the data;

[0137] S25. Import the calculation results into the CFD-post module in ANSYS software for post-processing.

[0138] S26. Based on the dimensions of the stirred tank and the liquid level, design the specific structure and dimensions of the feeding device. This includes the annular pipeline and the spiral nozzle. Determine the specifications of the spiral nozzle according to the predetermined spray range. The nozzle is a solid cone with an inner diameter of 2.4 mm and a spray particle size of 600-800 micrometers.

[0139] S27. Perform mesh generation and numerical simulation calculations on the stirred tank device with a feeding device, and save the data;

[0140] S28. Import the optimized flow field calculation results of the stirred tank into the CFD-post module of ANSYS software for post-processing.

[0141] S29. Compare and analyze the flow field results of the stirred tank before optimization with the flow field results after optimization using the feeding device to verify the feasibility of the feeding device in improving material distribution and preventing local scaling.

[0142] Depend on Figures 11a-11d The fluid velocity at the vertical cross-section and the volume fraction distribution of the mixed liquid phase inside the vessel reveal that the flow velocity within the stirred tank is concentrated near the impeller tip, while localized low-velocity zones exist near the liquid surface and near the wall. Figure 11e At mid-section a, a localized low-velocity zone can be observed near the liquid surface along the axial height, behind the baffle in the stirring direction, which may lead to prepolymer accumulation. Sections b-c show that at the mid-height, the flow velocity is higher near the impeller and lower between the vessel wall and the impeller. Near the bottom of the vessel (section d), the flow velocity is lower in the vessel wall area.

[0143] By tracking the trajectory of the prepolymer inside the reactor containing the feeding device of the embodiments of this disclosure and the reactor with single-tube dripping, the volume fraction distribution of the prepolymer at the cross-section can be obtained, such as... Figures 11f-11i As shown, it can be found that the prepolymer of the reactor containing the feeding device of the present disclosure has better uniformity of distribution in the reactor cross section than that of the single-tube dripping reactor. The prepolymer can be dispersed uniformly in the reactor cross section more quickly, without accumulating too much on the reactor wall and near the baffle, thus avoiding local over-reaction.

[0144] Besides the example of the reaction production process of isocyanate prepolymer and amino resin, the feeding device of the embodiments of this disclosure can also be applied to other reaction process devices that require enhanced liquid-liquid mixing. Furthermore, the computational fluid dynamics models and methods used in the embodiments of this disclosure can also provide reference for the structural design of other devices (e.g., spiral nozzles, stirred tank feeding devices, etc.).

[0145] In the embodiments of this disclosure, the material distribution state is analyzed using computational fluid dynamics methods. This eliminates the need for numerous difficult and tedious experimental operations, allowing for rapid verification of the feasibility of device structure optimization and saving significant time and experimental costs. This embodiment enables the quantification and visualization of more physical details such as velocity distribution and phase distribution within the vessel, thereby providing technical insights and theoretical support for the optimized design of the feeding device.

[0146] Embodiments of this disclosure also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the parameter optimization method for the feeding device provided in any of the above embodiments.

[0147] The readable storage medium may be more specifically adopted, including but not limited to: portable disk, hard disk, random access memory, read-only memory, erasable programmable read-only memory, optical storage device, magnetic storage device, or any suitable combination thereof.

[0148] Embodiments of this disclosure also provide a computer program product, including a computer program that, when executed by a processor, implements the parameter optimization method for the feeding device described in any of the preceding claims.

[0149] The program code for executing the computer program product of this disclosure can be written in any combination of one or more programming languages, and the program code can be executed entirely on a user device, partially on a user device, as a stand-alone software package, partially on a user device and partially on a remote device, or entirely on a remote device.

[0150] While specific embodiments of this disclosure have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this disclosure is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this disclosure, but all such changes and modifications fall within the scope of protection of this disclosure.

Claims

1. A feeding device, characterized in that, The feeding device includes: a feeding pipeline, an annular pipeline, and at least two spiral nozzles; the feeding pipeline includes a main feeding branch pipe and at least two branch pipes for diversion, the main feeding branch pipe being connected to the annular pipeline through the branch pipes for diversion, and each spiral nozzle being distributed on the annular pipeline.

2. The feeding device according to claim 1, characterized in that, The number of spiral nozzles is determined based on the spray range of the spiral nozzles and the cross-section of the reactor contained in the reaction process apparatus, and the feeding device is applied to the reaction process apparatus.

3. The feeding device according to claim 1, characterized in that, Each spiral nozzle is arranged at equal intervals on the annular pipe; And / or, each branch pipe is installed at equal intervals on the annular pipeline; And / or, the number of the spiral nozzles is four; And / or, the number of the branch pipes is 2.

4. The feeding device according to claim 1, characterized in that, The feed pipeline also includes a feed reducer, the first end of which is fixed to the feed inlet at the top of the reactor included in the reaction process device, and the second end of which is connected to the main feed branch pipe; wherein, the inner diameter of the first end is larger than the inner diameter of the second end, and the feed device is used in the reaction process device.

5. The feeding device according to any one of claims 1-4, characterized in that, The feeding device also includes a pulse generator; The pulse generator is located inside the main feed branch pipe; or the feeding device further includes an external feed pipe, and the pulse generator is located inside the external feed pipe; the external feed pipe is located outside the reactor; the external feed pipe is connected to the main feed branch pipe, or if the feed pipeline includes a feed reducer, the external feed pipe is connected to the feed reducer.

6. The feeding device according to claim 5, characterized in that, The pulse generator produces pressure pulses at a fixed frequency; wherein the fixed frequency is an empirical value, or the fixed frequency is obtained by simulation calculation of a reactor with the built-in feeding device. And / or, the pulse intensity of the pulse generator is in the range of [0.1 MPa, 0.5 MPa]; the pulse intensity is an empirical value, or the pulse intensity is obtained by simulation calculation of the reactor with the built-in feeding device; And / or, the feeding device further includes a pressure regulating valve, which is located inside the main feeding branch pipe or the external feeding pipe.

7. The feeding device according to claim 6, characterized in that, The feeding device further includes a flow sensor, a pressure sensor, and a controller. The controller is electrically connected to the flow sensor, the pressure sensor, and the pulse generator, respectively. The flow sensor and the pressure sensor are arranged inside the main feed branch pipe or the external feed pipe, and the flow sensor and the pressure sensor are located downstream of the pressure regulating valve and upstream of the pulse generator. The controller is used to adjust the pulse frequency of the pulse generator according to the flow data detected by the flow sensor and the pressure data detected by the pressure sensor until the flow data and the pressure data meet the preset conditions.

8. A reaction process apparatus, characterized in that, Includes a reaction vessel and a feeding device according to any one of claims 1-7; The reactor is provided with a feed inlet at the top, the feed device is located inside the reactor, and the feed pipeline is connected to the feed inlet.

9. A method for optimizing the parameters of a feeding device, characterized in that, The parameter optimization method is used to optimize the structural parameters of the feeding device according to any one of claims 1-7; the parameter optimization method includes the following steps: The flow field calculation results of the reactor with the built-in feeding device were obtained through numerical simulation; The structural parameters of the feeding device are optimized based on the flow field calculation results; wherein the structural parameters include at least one of the following: the number of branch pipes, the number of spiral nozzles, the angle of the spiral nozzles, the layout of the spiral nozzles, the layout of the branch pipes, the size of the main feed branch pipe, the size of the branch pipes, the size of the annular pipe, the connection method between the spiral nozzles and the annular pipe, the pulse frequency of the pulse generator, and the pulse intensity of the pulse generator.

10. The parameter optimization method for the feeding device according to claim 9, characterized in that, Optimize the structural parameters of the feeding device based on the flow field calculation results, including: The kurtosis value of the prepolymer concentration in the cross section is determined based on the flow field calculation results. Optimize the structural parameters of the feeding device based on the kurtosis value of the prepolymer concentration in the cross section; The formula for calculating the kurtosis value of the prepolymer concentration in the cross section is as follows: Where n represents the number of cross-sectional data points of the reactor, i represents the i-th data point, and c i This represents the concentration value of the i-th data point. SD represents the sample concentration mean, and SD represents the sample concentration standard deviation.

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