Pipeline premixer, multi-component liquid-phase reactant pipeline premixing system and method and application of pipeline premixer and multi-component liquid-phase reactant pipeline premixing system and method

Abstract

The invention provides a pipeline premixer, a multi-component liquid-phase reactant pipeline premixing system and method and application of the pipeline premixer and the multi-component liquid-phase reactant pipeline premixing system and method. The pipeline premixer is used for pre-mixing multi-component liquid phase reactants and sequentially comprises a variable-pitch spiral flow guide section, a spiral flow guide section, a spiral flow guide section and a flow guide section in the fluid direction, and the variable-pitch spiral flow guide section is used for increasing the fluid Reynolds number to a turbulent flow area; the multi-taper-hole shear plate section is used for shearing fluid so as to generate a local cavitation effect; and the helical tooth staggered mixed grid section is used for enabling the fluid to generate a Karman vortex street. Compared with the prior art, the pipeline premixer, the multi-component liquid phase reactant pipeline premixing system, the method and the application have the advantages that molecular-level uniform mixing of multi-component reactants is realized by arranging the variable-pitch spiral flow guide section, the multi-taper-hole shear plate section and the helical-tooth staggered mixing grid section; therefore, the problem of non-uniform component distribution caused by mixing delay in the kettle can be solved.

Description

Technical Field

[0001] This invention relates to the field of chemical reaction engineering technology, and in particular to a pipeline premixer, a multi-component liquid phase reactant pipeline premixing system, method, and application thereof. Background Technology

[0002] In multi-component co-precipitation synthesis (such as precursors for ternary cathode materials in lithium batteries with a chemical composition of nickel-cobalt-manganese hydroxide), traditional processes use separate pipelines to directly introduce each reaction solution into the reactor. However, this method has three major drawbacks: 1. Mixing lag: Due to differences in diffusion rates within the reactor, localized concentration unevenness occurs. Experiments show that Ni synthesized using traditional methods... 0.8 Co 0.1 Mn 0.1 In (OH)2 (NCM811), the Ni / Co / Mn elemental distribution deviation reaches ±8% (EDS surface scan data).

[0003] 2. Response delay: When adjusting the raw material ratio (e.g., NCM111→NCM811), it takes more than 30 minutes to reach a new steady state, during which a large amount of unqualified transition material is generated.

[0004] 3. Product defects: XRD analysis showed local lattice distortion (15% increase in full width at half maximum), which led to a decrease in battery cycle performance. Summary of the Invention

[0005] To address the technical problems in the prior art, this invention provides a pipeline premixer capable of achieving uniform mixing, a pipeline premixing system for multi-component liquid phase reactants, a method, and their applications.

[0006] A pipeline premixer for premixing multi-component liquid-phase reactants, comprising, in sequence along the fluid direction: The variable pitch helical guide section is used to increase the Reynolds number of the fluid to the turbulent region; Multi-conical-hole shear plate segments are used to shear fluids to produce a localized cavitation effect; The helical toothed interleaved mixing grid is used to generate a Karman vortex street in the fluid.

[0007] Preferably, the variable pitch spiral guide section includes multiple longitudinally arranged spiral blades, with the spiral blade pitch gradually changing from 0.5D at the inlet end to 0.2D at the outlet end, where D is the inner diameter of the pipe.

[0008] Preferably, the multi-conical-hole shearing plate section has multi-conical-hole shearing plates at both ends, each multi-conical-hole shearing plate having multiple conical holes, each conical hole having a cone angle α = 30-60 degrees, an opening ratio of 50%-70%, and a hole diameter of φ1-5mm, producing >1000s -1 The shear rate.

[0009] Preferably, the side of the multi-conical hole shear plate is further provided with guide grooves that are connected to the conical surface of the conical hole and radially distributed, with a groove depth of 0.5-2mm and a groove width of 1-3mm.

[0010] Preferably, the helical toothed mixed grid section is provided with a plurality of helical toothed plates arranged in a grid shape, and the helical toothed plates are provided with a plurality of toothed pieces, the toothed piece inclination angle β=30-60 degrees, and the tooth height h=0.2D-0.4D.

[0011] Preferably, the inner surface of the pipe is coated with a PTFE-TiO2 composite superhydrophobic coating with a thickness of 50-200μm and a static contact angle ≥150 degrees.

[0012] A multi-component liquid-phase reactant pipeline premixing system, comprising: Multiple feed lines are provided, each for transporting different liquid phase reactants. Each feed line is equipped with a mass flow meter and a regulating valve. A pipeline premixer, employing the pipeline premixer described above, wherein the pipeline premixer is connected to the outlet of at least a portion of the feed line; An online concentration analyzer, installed downstream of the pipeline premixer, is used to detect the concentration of each component in the mixed solution produced by the pipeline premixer; The controller connects each regulating valve to the online concentration analyzer and is used to dynamically adjust the flow rate of liquid reactants in each feed line based on the component concentration data detected by the online concentration analyzer.

[0013] A method for premixing multi-component liquid-phase reactants in a pipeline, employing the multi-component liquid-phase reactant pipeline premixing system described above, includes the following steps: S1. Set the target proportions for each component, and initialize the control valve opening of the controller; S2. Turbulence is generated as the solution flows through the variable pitch spiral guide section; S3. Local cavitation effect is generated through the multi-conical-hole shear plate segment, with a shear rate > 1000s. -1 ; S4. Microscale mixing is achieved by inducing the generation of Karman vortex street through the helical toothed interleaved mixing grid segment; S5, the online concentration analyzer detects the concentration of each component in the mixed solution produced by the pipeline premixer and feeds the data back to the controller in real time, so that the controller can dynamically adjust the flow rate.

[0014] A method for synthesizing OLED material Ir(ppy)3 employs the multi-component liquid-phase reactant premixing method described above. The method has three feed lines, which are used to transport IrCl3 solution, ppy ligand solution and reducing agent solution respectively, with a molar ratio of 1:3:1.5.

[0015] A method for synthesizing a ternary cathode material precursor for lithium-ion batteries employs the multi-component liquid-phase reactant pipeline premixing method described above. The method has five feed pipelines, which are used to transport nickel salt solution, cobalt salt solution, manganese salt solution, sodium hydroxide solution, and ammonia solution, respectively. The nickel salt solution, cobalt salt solution, and manganese salt solution are added to the synthesis reactor simultaneously with the sodium hydroxide solution and ammonia solution after flowing through the pipeline premixer.

[0016] Compared with the prior art, the pipeline premixer, multi-component liquid phase reactant pipeline premixing system, method and application provided by the present invention achieve molecular-level uniform mixing of multi-component reactants by setting up a variable pitch spiral guide section, a multi-conical hole shear plate section and an oblique tooth staggered mixing grid section, thereby solving the problem of uneven component distribution caused by mixing lag in the reactor. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A perspective view of a pipeline premixer provided in one embodiment; Figure 2 for Figure 1 The front view of the pipeline premixer shown; Figure 3 for Figure 1 Top view of the pipe premixer shown; Figure 4 for Figure 1 A schematic diagram of the internal structure of the pipeline premixer shown. Figure 5 for Figure 1 A schematic diagram of the variable pitch spiral guide section in the pipeline premixer shown; Figure 6 for Figure 1 A schematic diagram of the multi-conical-hole shear plate section in the pipeline premixer shown; Figure 7 for Figure 1 A schematic diagram of the staggered mixing grid section in the pipeline premixer shown; Figure 8 for Figure 7 A schematic diagram of one helical tooth plate in the helical tooth interleaved hybrid grid segment shown; Figure 9 for Figure 1 A schematic diagram of a multi-component liquid phase reactant pipeline premixing system used in the pipeline premixer shown; Figure 10 for Figure 9 The diagram shows a comparison of the surface thermograms of nickel distribution in ternary precursor particles during the synthesis reaction of ternary cathode material precursors for lithium-ion batteries using a multi-component liquid phase reactant pipeline premixing system, with those obtained using traditional methods. Figure 11 for Figure 9 The diagram shows a multi-component liquid-phase reactant pipeline premixing system applied to the synthesis of a ternary precursor core-shell gradient structure. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0021] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0022] like Figures 1 to 8 As shown, this embodiment of the invention provides a pipeline premixer for premixing multi-component liquid-phase reactants. The main body of the pipeline premixer is a generally cylindrical pipeline with multiple fluid inlets 1 at one end and a fluid outlet 2 at the other end. Along the fluid direction, it sequentially includes a variable pitch spiral guide section 3, a multi-conical hole shear plate section 4, and an oblique toothed interlaced mixing grid section 5.

[0023] The variable-pitch helical guide section 3 is used to increase the Reynolds number of the fluid to the turbulent region (Reynolds number Re > 10000). In this embodiment, the variable-pitch helical guide section 3 includes multiple longitudinally arranged helical blades 31 (7 in this embodiment, e.g., ...). Figure 5The pitch of the spiral blade 31 gradually changes from 0.5D at the inlet end to 0.2D at the outlet end, where D is the inner diameter of the pipe.

[0024] The multi-conical-hole shear plate segment 4 is used to shear the fluid to generate a localized cavitation effect. In this embodiment, as... Figure 6 As shown, the multi-conical-hole shearing plate section 4 has multi-conical-hole shearing plates 41 at both ends. Each multi-conical-hole shearing plate 41 has multiple conical holes 42 (a conical hole refers to a hole that is conical, with one side having a larger diameter and the other side having a smaller diameter). The cone angle α of each conical hole 42 is 30-60 degrees, the opening rate is 50%-70%, and the hole diameter is φ1-5mm, producing >1000s -1 The shearing rate. The side of the multi-conical hole shear plate 41 is also provided with guide grooves 43 that are connected to the conical surface of the conical hole 42 and radially distributed, with a groove depth of 0.5-2mm and a groove width of 1-3mm.

[0025] The helical toothed interlaced mixing grid segment 5 is used to generate a Karman vortex street in the fluid to achieve microscale mixing. In this embodiment, as... Figure 7 , Figure 8 As shown, the helical toothed mixed grid section 5 has multiple helical toothed plates 51 arranged in a grid shape, and multiple toothed plates 511 are provided on the helical toothed plates 51. The inclination angle β of the toothed plates 511 is 30-60 degrees, and the tooth height h is 0.2D-0.4D.

[0026] Furthermore, in this embodiment, the inner surface of the pipe premixer is coated with a PTFE-TiO2 composite superhydrophobic coating with a thickness of 50-200μm and a static contact angle ≥150 degrees.

[0027] like Figure 9 As shown, this embodiment also provides a multi-component liquid-phase reactant pipeline premixing system, including: Multiple feed lines 11 are provided, each feed line 11 is used to transport each liquid phase reactant, and each feed line 11 is equipped with a mass flow meter 12 and a regulating valve 13 (electronic regulating valve in this embodiment). The pipeline premixer 14, as described above, is connected to the outlet of at least a portion of the feed line 11. An online concentration analyzer 15 is installed downstream of the pipeline premixer 14 (e.g., on the pipeline between the pipeline premixer 14 and the synthesis vessel 16) to detect the concentration of each component in the mixed solution produced by the pipeline premixer 14. The controller (not shown) connects each regulating valve 13 to the online concentration analyzer 15 and is used to dynamically adjust the flow rate of the liquid phase reactants in each feed line 11 based on the component concentration data detected by the online concentration analyzer 15.

[0028] This embodiment also provides a method for premixing multi-component liquid-phase reactants in a pipeline, using the multi-component liquid-phase reactant pipeline premixing system described above, and the method includes the following steps: S1. Set the target proportions for each component, and initialize the control valve opening of the controller; S2. Turbulence is generated as the solution flows through the variable pitch spiral guide section; S3. Local cavitation effect is generated through the multi-conical-hole shear plate segment, with a shear rate > 1000s. -1 ; S4. Microscale mixing is achieved by inducing the generation of Karman vortex street through the helical toothed interleaved mixing grid segment; S5, the online concentration analyzer detects the concentration of each component in the mixed solution produced by the pipeline premixer and feeds the data back to the controller in real time, so that the controller can dynamically adjust the flow rate.

[0029] In step S2, the uniformity CV value of the fluid after passing through the three-stage mixing unit is ≤0.9%, and the pressure drop is ≤0.15MPa.

[0030] This embodiment also provides a scheme for applying the above-mentioned multi-component liquid-phase reactant pipeline premixing system to the synthesis reaction of ternary cathode material precursors for lithium-ion batteries. This method for synthesizing ternary cathode material precursors for lithium-ion batteries employs the multi-component liquid-phase reactant pipeline premixing method described above. It has five feed pipelines, respectively used to transport nickel salt solution, cobalt salt solution, manganese salt solution, sodium hydroxide solution, and ammonia solution. The nickel salt solution, cobalt salt solution, and manganese salt solution flow through the pipeline premixer and are then simultaneously added to the synthesis reactor along with the sodium hydroxide solution and ammonia solution.

[0031] The specific implementation plan is described below.

[0032] The process parameters are shown in the table below.

[0033]

[0034] Its operation process is as follows: The target elemental ratio for synthesizing nickel-cobalt-manganese hydroxide was set as Ni:Co:Mn = 80:10:10; Nickel sulfate solution, cobalt sulfate solution, and manganese sulfate solution flow through a three-stage mixing unit; The concentration is monitored in real time using an online concentration analyzer (such as LIBS or laser-induced breakdown spectrometer), and the flow rate is controlled by dynamically adjusting the valve using a PID (proportional-integral-derivative) control system. The matching sodium hydroxide solution and ammonia solution were added to the synthesis reactor simultaneously.

[0035] The test results are shown in the table below:

[0036] Note: The Span value is used to characterize the particle size distribution. It is calculated as (D90-D10) / D50. The smaller the value, the more concentrated the particle size distribution and the more controllable the reaction.

[0037] If traditional in-reactor mixing is used (comparative example), under the same raw materials and proportions, the Ni content of the product fluctuates by 72-85% in the first 30 minutes of reaction. TEM shows that the local Co / Mn ratio reaches 1:1.8, and the batch transition material accounts for 18% (only 2% in this invention). A comparison of the nickel element distribution thermograms is shown below. Figure 10 As shown.

[0038] The aforementioned multi-component liquid-phase reactant pipeline premixing system can also be applied to synthetic reactions such as pharmaceutical intermediates where strict uniformity of component ratios is required. For example, it can be used in the synthesis of OLED material Ir(ppy)3. The synthesis method employs the multi-component liquid-phase reactant pipeline premixing method described above, with three feed lines used to transport IrCl3 solution, ppy ligand solution, and reducing agent solution, respectively, in a molar ratio of 1:3:1.5.

[0039] The details are as follows.

[0040] As a high-efficiency phosphorescent OLED material, the synthesis of Ir(ppy)3 requires extremely high mixing uniformity. Its reaction mechanism is: IrCl3·3H2O + 3 ppyH + reducing agent → Ir(ppy)3 + byproduct. The molar ratio of Ir:ppy ligand: reducing agent must be strictly controlled to be 1:3:1.5.

[0041] This embodiment uses a mixed three-component organometallic solution (IrCl3 / ppy ligand / reducing agent), which improves the fluorescence quantum efficiency of the product to 92% (compared to 85% for conventional methods). It is particularly suitable for high-viscosity organic systems (viscosity ≤ 500 cP).

[0042] Its system components are:

[0043] Its parameters are controlled as follows:

[0044] The results of their operation are compared as follows:

[0045] The aforementioned multi-component liquid-phase reactant pipeline premixing system can also be applied to the synthesis of ternary precursor core-shell gradient variation structures.

[0046] Its system configuration is as follows: Pipe diameter DN50, material PPH; Online LIBS analyzer (accuracy ±0.1%); The superhydrophobic coating is 150μm thick.

[0047] Its process parameters are:

[0048] Its operation process is as follows: The target proportions of elements in the synthesis of nickel-cobalt-manganese hydroxide were set according to the core-shell gradient structure; Nickel sulfate, cobalt sulfate, and manganese sulfate solutions flow through a three-stage mixing unit; LIBS monitors concentration in real time, and PID dynamically adjusts valves to control flow. The matching sodium hydroxide solution and ammonia solution were added to the synthesis reactor simultaneously.

[0049] The synthesis target is: the particle D50 is 5μm, the core of the sphere is Ni:Co:Mn=90:0:10, and the composition gradually changes to Ni:Co:Mn=80:10:10, Ni:Co:Mn=60:20:20, Ni:Co:Mn=50:20:30.

[0050] The relationship of its operating flow control function is as follows:

[0051] The precursor graded core-shell structure obtained by the above method is as follows: Figure 11 As shown.

[0052] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A pipeline premixer for premixing multi-component liquid-phase reactants, characterized in that, Along the fluid direction, the following are included in sequence: The variable pitch helical guide section is used to increase the Reynolds number of the fluid to the turbulent region; Multi-conical-hole shear plate segments are used to shear fluids to produce a localized cavitation effect; The helical toothed interleaved mixing grid is used to generate a Karman vortex street in the fluid.

2. The pipeline premixer according to claim 1, characterized in that, The variable pitch spiral guide section includes multiple longitudinally arranged spiral blades, with the spiral blade pitch gradually changing from 0.5D at the inlet end to 0.2D at the outlet end, where D is the inner diameter of the pipe.

3. The pipeline premixer according to claim 1, characterized in that, The multi-conical-hole shearing plate section has multi-conical-hole shearing plates at both ends. Each multi-conical-hole shearing plate has multiple conical holes, each with a cone angle α = 30-60 degrees, an opening ratio of 50%-70%, and a hole diameter of φ1-5mm, producing >1000s. -1 The shear rate.

4. The pipeline premixer according to claim 3, characterized in that, The side of the multi-conical hole shear plate is also provided with guide grooves that are connected to the conical surface of the conical hole and are radially distributed, with a groove depth of 0.5-2mm and a groove width of 1-3mm.

5. The pipeline premixer according to claim 1, characterized in that, The helical toothed mixed grid section is provided with multiple helical toothed plates arranged in a grid shape, and multiple toothed plates are provided on the helical toothed plates. The toothed plate inclination angle β = 30-60 degrees and the tooth height h = 0.2D-0.4D.

6. The pipeline premixer according to claim 1, characterized in that, The inner surface of the pipe is coated with a PTFE-TiO2 composite superhydrophobic coating with a thickness of 50-200μm and a static contact angle of ≥150 degrees.

7. A multi-component liquid-phase reactant pipeline premixing system, characterized in that, include: Multiple feed lines are provided, each for transporting different liquid phase reactants. Each feed line is equipped with a mass flow meter and a regulating valve. A pipeline premixer, as described in any one of claims 1 to 6, wherein the pipeline premixer is connected to the outlet of at least a portion of the feed line; An online concentration analyzer, installed downstream of the pipeline premixer, is used to detect the concentration of each component in the mixed solution produced by the pipeline premixer; The controller connects each regulating valve to the online concentration analyzer and is used to dynamically adjust the flow rate of liquid reactants in each feed line based on the component concentration data detected by the online concentration analyzer.

8. A method for premixing multi-component liquid-phase reactants in a pipeline, characterized in that, The method using the multi-component liquid-phase reactant pipeline premixing system as described in claim 7 includes the following steps: S1. Set the target proportions for each component, and initialize the control valve opening of the controller; S2. Turbulence is generated as the solution flows through the variable pitch spiral guide section; S3. Local cavitation effect is generated through the multi-conical-hole shear plate segment, with a shear rate > 1000s. -1 ; S4. Microscale mixing is achieved by inducing the generation of Karman vortex street through the helical toothed interleaved mixing grid segment; S5, the online concentration analyzer detects the concentration of each component in the mixed solution produced by the pipeline premixer and feeds the data back to the controller in real time, so that the controller can dynamically adjust the flow rate.

9. A method for synthesizing OLED material Ir(ppy)3, characterized in that, The multi-component liquid-phase reactant pipeline premixing method described in claim 8 has three feed pipelines, which are used to transport IrCl3 solution, ppy ligand solution and reducing agent solution respectively, with a molar ratio of 1:3:1.

5.

10. A method for synthesizing a ternary cathode material precursor for lithium-ion batteries, characterized in that, The multi-component liquid phase reactant pipeline premixing method described in claim 8 has five feed pipelines, which are used to transport nickel salt solution, cobalt salt solution, manganese salt solution, sodium hydroxide solution, and ammonia solution, respectively. The nickel salt solution, cobalt salt solution, and manganese salt solution are added to the synthesis reactor simultaneously with the sodium hydroxide solution and ammonia solution after flowing through the pipeline premixer.

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