A controllable dispersion system device suitable for micro-suspension emulsions

Abstract

This invention discloses a controllable dispersion system for micro-suspension emulsions, comprising a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump, and a second three-way valve. This system can improve monomer seed quality, achieve controllable emulsion particle size, reduce energy consumption, and ensure product quality stability. Depending on the internal components and parameters, the controllable emulsion particle size obtained after emulsification ranges from 0.56 to 0.70 μm, and the distribution index ranges from 0.320 to 0.400.

Description

Technical Field

[0001] This invention belongs to the field of micro-suspension emulsion preparation technology, and in particular relates to a controllable dispersion system device suitable for micro-suspension emulsions. Background Technology

[0002] Microsuspension polymerization is a technique for preparing polymer microparticles. It involves dispersing monomers in a liquid medium to form tiny droplets, and then carrying out polymerization reactions within these droplets. This method combines the advantages of suspension polymerization and emulsion polymerization, enabling the production of polymer particles with uniform size and narrow particle size distribution. Microsuspension polymerization can be used to produce a variety of products, including polystyrene microspheres for laboratory reagents and biomedical applications, polyacrylate microspheres for coatings and adhesives, polyurethane microspheres for textile finishing and coatings, and polyvinyl chloride paste resins for flooring materials, coatings, and synthetic leather.

[0003] The preparation of micro-suspension emulsions is crucial in micro-suspension polymerization. By precisely controlling the emulsion formation process, uniform droplet size can be obtained, which plays a decisive role in the final polymer particle size and distribution. In the past, micro-suspension emulsion preparation often used stirred tanks. For example, Chinese patent CN214327614U uses dispersion tanks for mechanical homogenization, and Chinese patent application CN105498586A proposes using multi-layered and different types of stirring paddles to achieve more effective and dispersed mixing and dispersion of materials. However, the above emulsification methods suffer from problems such as uneven droplet size distribution, large emulsifier dosage, incomplete emulsification, and high energy consumption during long-term operation.

[0004] To address the aforementioned issues, Chinese patent application CN106883331A introduced a homogenizing pump for emulsification based on traditional processes, successfully producing a finished product with an average particle size of 1.10 μm. Despite improvements in the process equipment, challenges remain, including increased wear on equipment components due to high shear forces, increased maintenance costs, the need for additional cooling due to temperature rise during the shearing process, and high energy consumption resulting from high-pressure operation.

[0005] Therefore, to address the aforementioned technical challenges, there is an urgent need to develop more efficient emulsification equipment to obtain higher quality monomer seeds. This invention proposes a premixing system to improve the dispersion efficiency of micro-suspension emulsions. Through internal structural design, it achieves efficient droplet dispersion and uniform mixing. Summary of the Invention

[0006] The technical problem this invention aims to solve is to provide a controllable dispersion system device suitable for micro-suspension emulsions. This dispersion system device can solve many problems existing in the pretreatment premixing and dispersion of current micro-suspension polymerization production processes. Through this system, the quality of monomer seeds can be improved, the particle size of the emulsion can be controlled, energy consumption can be reduced, and the stability of product quality can be ensured. Depending on the internal components and parameters, the controllable emulsion particle size obtained after emulsification ranges from 0.56 to 0.70 μm, and the distribution index ranges from 0.320 to 0.400.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A controllable dispersion system device suitable for micro-suspension emulsions includes a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump, and a second three-way valve.

[0009] The first static mixer is covered by a first ultrasonic transducer;

[0010] The first ultrasonic generator transmits ultrasonic energy to the first static mixer through an ultrasonic transducer.

[0011] The inlet of the first static mixer is connected to the raw material liquid pipeline;

[0012] The outlet of the first static mixer is connected to the inlet of the first homogenizing pump via a pipeline;

[0013] The outlet of the first homogenizing pump is connected to the inlet of the first three-way valve via a pipeline.

[0014] One outlet of the first three-way valve flows back to the raw material liquid pipeline through a pipeline;

[0015] The other outlet of the first three-way valve is connected to the inlet of the second static mixer via a pipeline; the second static mixer is covered by a second ultrasonic transducer;

[0016] The second ultrasonic generator transmits ultrasonic energy to the second static mixer via an ultrasonic transducer;

[0017] The outlet of the second static mixer is connected to the inlet of the second homogenizing pump via a pipeline;

[0018] The outlet of the second homogenizing pump is connected to the inlet of the second three-way valve via a pipeline.

[0019] One outlet of the second three-way valve flows back through a pipe to the inlet pipe of the second static mixer;

[0020] The other outlet of the second three-way valve is connected to the product storage tank via a pipeline.

[0021] Preferably, the ultrasonic frequency setting range of the first ultrasonic generator is 10 to 30 kHz; and the ultrasonic frequency setting range of the second ultrasonic generator is 30 to 50 kHz.

[0022] Preferably, the length-to-diameter ratio of both the first static mixer and the second static mixer is in the range of 6-10, and the diameter of the mixing pipe of the first static mixer and the second static mixer is less than 12cm.

[0023] Preferably, when one outlet of the first three-way valve flows back into the raw material liquid pipeline through a pipeline, the reflux ratio ranges from 2 to 5.

[0024] Preferably, the number of mixing elements in both the first static mixer and the second static mixer is 4-8, and the mixing pipes of the first static mixer and the second static mixer are provided with spiral blades.

[0025] Preferably, when the mixing elements in the first static mixer and the second static mixer are installed, the degree of overlap between adjacent spiral blades is in the range of 45° to 90°.

[0026] Preferably, the first and second static mixers are made of materials with high elastic modulus (such as titanium alloy or stainless steel); the maximum wall thickness of the mixing elements in the first and second static mixers is set to 5 cm.

[0027] Preferably, the inner diameters of the first and second static mixers gradually decrease from upstream to downstream, with a maximum reduction of no more than 6 cm.

[0028] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0029] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The controllable dispersion system of this invention couples a static mixer with an ultrasonic device to form an ultrasonic static mixer. The static mixer contains spiral blades with different torsion angles, enhancing the static mixing effect of the emulsion. Simultaneously, the static mixer is made of a material capable of effectively transmitting ultrasonic amplitude and is equipped with an external reflux system, reducing the final emulsion droplet size and resulting in a narrower particle size distribution. This equipment is applicable to all micro-suspension emulsion preparation processes and is of great significance for optimizing and improving micro-suspension emulsion preparation processes. Depending on the internal components and parameters, the controllable emulsion particle size range after emulsification is 0.56–0.70 μm, and the distribution index ranges from 0.320 to 0.400.

[0032] 2. This invention optimizes the micro-suspension emulsion dispersion process, reducing the required processing time, energy consumption, and material consumption, thereby significantly lowering production costs. Furthermore, the controllable particle size emulsion produced by this equipment can meet the production needs of different processes. Especially when used in the production of polyvinyl chloride paste resin, it can reduce the energy consumption for subsequent vinyl chloride monomer recovery, contributing to reduced environmental pollution and meeting the requirements of sustainable development. Attached Figure Description

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the controllable dispersion system device of the present invention;

[0035] Figure 2 This refers to the mixing element structure within the first and second static mixers of the present invention.

[0036] Reference numerals: 1-First static mixer, 2-First ultrasonic generator, 3-First ultrasonic transducer, 4-First homogenizing pump, 5-First three-way valve, 6-Second static mixer, 7-Second ultrasonic generator, 8-Second ultrasonic transducer, 9-Second homogenizing pump, 10-Second three-way valve. Detailed Implementation

[0037] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0038] In this embodiment of the invention, trichloroethylene is purchased from high-purity trichloroethylene produced by Shanghai Aladdin Biochemical Technology Co., Ltd., and sodium dodecyl sulfate and cetyl alcohol are purchased from Shanghai Maclean Biochemical Technology Co., Ltd., which are reagent-grade sodium dodecyl sulfate and high-purity cetyl alcohol, respectively.

[0039] See Figure 1As shown, as one aspect of the present invention, the present invention provides a controllable dispersion system device suitable for micro-suspension emulsions, comprising a first static mixer 1, a first ultrasonic generator 2, a first ultrasonic transducer 3, a first homogenizing pump 4, a first three-way valve 5, a second static mixer 6, a second ultrasonic generator 7, a second ultrasonic transducer 8, a second homogenizing pump 9, and a second three-way valve 10.

[0040] The first static mixer 1 is covered by a first ultrasonic transducer 3;

[0041] The first ultrasonic generator 2 transmits ultrasonic energy to the first static mixer 1 through the first ultrasonic transducer 3;

[0042] The inlet of the first static mixer 1 is connected to the raw material liquid pipeline;

[0043] The outlet of the first static mixer 1 is connected to the inlet of the first homogenizing pump 4 via a pipe;

[0044] The outlet of the first homogenizing pump 4 is connected to the inlet of the first three-way valve 5 via a pipeline.

[0045] One outlet of the first three-way valve 5 flows back to the raw material liquid pipeline through a pipeline;

[0046] The other outlet of the first three-way valve 5 is connected to the inlet of the second static mixer 6 via a pipeline; the second static mixer 6 is covered by a second ultrasonic transducer 8;

[0047] The second ultrasonic generator 7 transmits ultrasonic energy to the second static mixer 6 through the second ultrasonic transducer 8.

[0048] The outlet of the second static mixer 6 is connected to the inlet of the second homogenizing pump 9 via a pipe;

[0049] The outlet of the second homogenizing pump 9 is connected to the inlet of the second three-way valve 10 via a pipeline.

[0050] One outlet of the second three-way valve 10 flows back to the inlet pipe of the second static mixer 6 through a pipe;

[0051] The other outlet of the second three-way valve 10 is connected to the product storage tank via a pipeline.

[0052] According to certain embodiments of the present invention, the ultrasonic frequency setting range of the first ultrasonic generator is 10–30 kHz; the ultrasonic frequency setting range of the second ultrasonic generator is 30–50 kHz. By connecting the low frequency and high frequency in series, a large number of cavitation bubbles are first generated using the low frequency, and then the bubbles are torn apart using the high frequency to obtain a lower emulsion particle size and a narrower emulsion particle size distribution.

[0053] According to certain embodiments of the present invention, the aspect ratio of both the first static mixer and the second static mixer is in the range of 6-10, and the diameter of the mixing pipes of the first static mixer and the second static mixer is less than 12 cm. Providing sufficiently long pipes ensures effective dispersion of the ultrasonic static mixing emulsion.

[0054] According to certain embodiments of the present invention, when one outlet of the first three-way valve flows back into the raw material liquid pipeline through a pipeline, the reflux ratio ranges from 2 to 5; when one outlet of the second three-way valve flows back into the inlet pipeline of the second static mixer through a pipeline, the reflux ratio ranges from 2 to 5. A suitable reflux ratio can increase the residence time of the material in the system, ensuring thorough mixing and uniform emulsification, while also enabling finer control over droplet size and obtaining a more uniform particle size distribution.

[0055] According to certain embodiments of the present invention, see Figure 2 As shown, the number of mixing elements in both the first static mixer and the second static mixer is 4-8, preferably 6; the mixing pipes of the first static mixer and the second static mixer are provided with spiral blades to promote thorough mixing of the liquid.

[0056] According to certain embodiments of the present invention, when the mixing elements in the first and second static mixers are installed, the degree of overlap between adjacent spiral blades ranges from 45° to 90°. The torsion angle of the mixing elements can be clockwise or counterclockwise 180°, and preferably, mixing elements with different torsion directions are staggered and connected with an overlap angle of 90°.

[0057] According to certain embodiments of the present invention, in order to improve the transmission of ultrasonic amplitude within the static mixer, the first and second static mixers are made of materials with high elastic modulus (such as titanium alloy or stainless steel); the maximum wall thickness of the mixing elements within the first and second static mixers is set to 5 cm.

[0058] According to certain embodiments of the present invention, the inner diameters of the first static mixer and the second static mixer gradually decrease from upstream to downstream, with a maximum reduction of no more than 6 cm, in order to enhance the ultrasonic coverage area and thereby improve the mixing effect of the static mixer.

[0059] Example 1

[0060] A controllable dispersion system for micro-suspension emulsions includes a first static mixer 1, a first ultrasonic generator 2, a first ultrasonic transducer 3, a first homogenizing pump 4, a first three-way valve 5, a second static mixer 6, a second ultrasonic generator 7, a second ultrasonic transducer 8, a second homogenizing pump 9, and a second three-way valve 10.

[0061] The first static mixer 1 is covered by a first ultrasonic transducer 3;

[0062] The first ultrasonic generator 2 transmits ultrasonic energy to the first static mixer 1 through the first ultrasonic transducer 3;

[0063] The inlet of the first static mixer 1 is connected to the raw material liquid pipeline;

[0064] The outlet of the first static mixer 1 is connected to the inlet of the first homogenizing pump 4 via a pipe;

[0065] The outlet of the first homogenizing pump 4 is connected to the inlet of the first three-way valve 5 via a pipeline.

[0066] One outlet of the first three-way valve 5 flows back to the raw material liquid pipeline through a pipeline;

[0067] The other outlet of the first three-way valve 5 is connected to the inlet of the second static mixer 6 via a pipeline; the second static mixer 6 is covered by a second ultrasonic transducer 8;

[0068] The second ultrasonic generator 7 transmits ultrasonic energy to the second static mixer 6 through the second ultrasonic transducer 8.

[0069] The outlet of the second static mixer 6 is connected to the inlet of the second homogenizing pump 9 via a pipe;

[0070] The outlet of the second homogenizing pump 9 is connected to the inlet of the second three-way valve 10 via a pipeline.

[0071] One outlet of the second three-way valve 10 flows back to the inlet pipe of the second static mixer 6 through a pipe;

[0072] The other outlet of the second three-way valve 10 is connected to the product storage tank via a pipeline.

[0073] A method for controllable dispersion of micro-suspension emulsions using the above-mentioned system device includes the following steps:

[0074] 1) A mixed solution containing 50 wt% soft water, 0.73 wt% sodium dodecyl sulfate, 0.54 wt% cetyl alcohol, and 48.73 wt% trichloroethylene was added to the first ultrasonic static mixer. The mixture was ultrasonically mixed (ultrasonic frequency 20 kHz) and then homogenized using the first homogenizing pump.

[0075] 2) Then send the homogenized liquid into the second ultrasonic static mixer (ultrasonic frequency 50kHz), start the second homogenization pump to obtain the final emulsion product. The reflux ratio of both ultrasonic static mixers is set to 3. When installing the mixing elements in the static mixer, the adjacent spiral blades are staggered by 90°, and the number of mixing elements is 6.

[0076] 3) The micro-suspension emulsion product is piped from one outlet of the second three-way valve to the product storage tank.

[0077] Example 2

[0078] Example 1 is repeated, except that the ultrasonic frequency of the first ultrasonic generator is 10 kHz.

[0079] Example 3

[0080] Example 1 is repeated, except that: the ultrasonic frequency of the first ultrasonic generator is 35kHz; when one outlet of the first three-way valve flows back to the raw material liquid pipeline through a pipeline, the reflux ratio is 4; when one outlet of the second three-way valve flows back to the inlet pipeline of the second static mixer through a pipeline, the reflux ratio is 4. With the reflux ratio changed to 4, the number of mixing elements in the first and second static mixers is set to 7, and the adjacent spiral blades are staggered by 60° during installation, otherwise it is exactly the same as in Example 2.

[0081] Example 4

[0082] Example 1 is repeated, except that: the ultrasonic frequency of the first ultrasonic generator is 30kHz, the adjacent spiral blades of the mixing elements in the first and second static mixers are staggered by 45° when installed, and the number of mixing elements in the first and second static mixers is set to 8. Everything else is exactly the same as in Example 1.

[0083] Comparative Example 1

[0084] The same as in Example 1 is repeated, except that the ultrasonic frequency of the first ultrasonic static mixer is changed to 40kHz, the ultrasonic frequency of the second ultrasonic static mixer is changed to 20kHz, the reflux ratio of the two ultrasonic static mixers is changed to 1, the number of mixing elements is set to 8, and the stagger degree of adjacent spiral blades is 0° during installation.

[0085] Comparative Example 2

[0086] A controllable dispersion system for micro-suspension emulsions is described. Two ultrasonic static mixers are replaced with homogenization tanks. 49.39 wt% soft water, 1.44 wt% sodium dodecyl sulfate, 1.07 wt% cetyl alcohol, and 48.10 wt% trichloroethylene are added to the first homogenization tank under stirring. The mixture is stirred thoroughly for 20 minutes, further homogenized using a homogenization pump, and then transferred to the second homogenization tank. When the liquid level in one tank reaches 10%, the second homogenization pump is started to obtain the emulsion. The rest is the same as in Example 1.

[0087] The product analysis indicators of Examples 1-4 and Comparative Examples 1-2 are shown in Table 1 below:

[0088] Table 1

[0089] content Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Average particle size (nm) 568.8 589.5 632.1 642.2 732.0 1380.0 Distribution index 0.321 0.338 0.355 0.383 0.452 0.548 Emulsifier dosage (wt%) 0.73 0.73 0.73 0.73 0.73 1.44 Co-emulsifier dosage (wt%) 0.54 0.54 0.54 0.54 0.54 1.07 Number of hybrid elements 6 6 7 8 8 ——

[0090] As can be seen from Table 1:

[0091] 1) Compared to Comparative Example 2, which uses two homogenization processes, the average particle size and distribution index obtained by using two ultrasonic static mixers are better, while the amount of emulsifier and co-emulsifier is significantly reduced.

[0092] 2) In Examples 1, 2, 3 and 4, the application of the ultrasonic static mixer resulted in an average particle size and distribution index that were far superior to those of Comparative Example 1, which had a non-preferred operating parameter range.

[0093] 3) Comparative Example 1 used a two-stage ultrasonic static mixing technology, which resulted in a smaller average particle size and more uniform distribution of the emulsion compared to the two-stage homogenization tank in Comparative Example 2.

[0094] The results of the embodiments show that the present invention can reduce material consumption, reduce mixing time, and prepare emulsions with smaller particle size and more uniform distribution.

[0095] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A controllable dispersion system device suitable for micro-suspension emulsions, characterized in that: It includes a first static mixer, a first ultrasonic generator, a first ultrasonic transducer, a first homogenizing pump, a first three-way valve, a second static mixer, a second ultrasonic generator, a second ultrasonic transducer, a second homogenizing pump, and a second three-way valve. The first static mixer is covered by a first ultrasonic transducer; The first ultrasonic generator transmits ultrasonic energy to the first static mixer through an ultrasonic transducer. The inlet of the first static mixer is connected to the raw material liquid pipeline; The outlet of the first static mixer is connected to the inlet of the first homogenizing pump via a pipeline; The outlet of the first homogenizing pump is connected to the inlet of the first three-way valve via a pipeline. One outlet of the first three-way valve flows back to the raw material liquid pipeline through a pipeline; The other outlet of the first three-way valve is connected to the inlet of the second static mixer via a pipeline; the second static mixer is covered by a second ultrasonic transducer; The second ultrasonic generator transmits ultrasonic energy to the second static mixer via an ultrasonic transducer; The outlet of the second static mixer is connected to the inlet of the second homogenizing pump via a pipeline; The outlet of the second homogenizing pump is connected to the inlet of the second three-way valve via a pipeline. One outlet of the second three-way valve flows back through a pipe to the inlet pipe of the second static mixer; The other outlet of the second three-way valve is connected to the product storage tank via a pipeline; The ultrasonic frequency setting range of the first ultrasonic generator is 10 to 30 kHz; the ultrasonic frequency setting range of the second ultrasonic generator is 30 to 50 kHz. The length-to-diameter ratio of both the first static mixer and the second static mixer is 6-10, and the diameter of the mixing pipes of the first static mixer and the second static mixer is less than 12cm. When one outlet of the first three-way valve flows back to the raw material liquid pipeline through a pipeline, the reflux ratio ranges from 2 to 5. The first static mixer and the second static mixer each contain 4-8 mixing elements, and the mixing pipes of the first static mixer and the second static mixer are equipped with spiral blades. When the mixing elements in the first and second static mixers are installed, the degree of overlap between adjacent spiral blades ranges from 45° to 90°. The inner diameters of the first and second static mixers gradually decrease from upstream to downstream, with a reduction of ≤6cm.

2. The controllable dispersion system device for micro-suspension emulsions according to claim 1, characterized in that: The first and second static mixers are made of titanium alloy or stainless steel; the wall thickness of the mixing elements in the first and second static mixers is ≤5cm.

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