Ultrasonic microreactor

Abstract

The utility model discloses an ultrasonic microreactor which is formed by directly attaching an ultrasonic transducer and a microreactor, the ultrasonic microreactor is formed by connecting a plurality of fluid microchannel reaction layers in series; the fluid micro-channel reaction layer is formed by alternately connecting a plurality of thin channels and thick channels; a reaction layer turbulent flow chip is arranged in the middle of the thick channel; under the synergistic effect of ultrasound and the microreactor, the ultrasonic microreactor has higher energy density and more accurate sound field and flow field regulation and control capability, and can solve the problems that channels are easy to block and the like, so that nano-emulsion with uniform particle size can be continuously prepared, and the efficiency of an emulsification process and the quality of an emulsion product are improved.

Description

Technical Field

[0001] The utility model relates to the cross technical field of chemical engineering and polymer material preparation, in particular to an ultrasonic microreactor. Background Art

[0002] Waterborne polyurethane dispersions use deionized water as the dispersion medium, significantly reducing the use of volatile organic solvents (VOCs). They are non-toxic, odorless, and environmentally friendly organic polymers. During use, the water evaporates to form a polyurethane film, giving the film-forming product of waterborne polyurethane dispersions the same outstanding physical and chemical properties as the original polyurethane material. Through formulation adjustments and chemical modifications, waterborne polyurethane materials can be produced to achieve high-performance properties with varying degrees of hardness and chemical resistance. They are widely used in wood coatings, textile coatings, synthetic leather, plastic coatings, metal coatings, personal care products, coatings, adhesives, sealants, and water-based inks.

[0003] Traditional polyurethane prepolymer dispersion is generally done using a high-speed disperser. The high-speed rotation of the dispersion disc shears the prepolymer into tiny liquids and evenly disperses them in water to form a uniform emulsion. This production process has the following main disadvantages: (1) long emulsification time, low production efficiency, and high production costs; (2) the production process is overly dependent on manual labor and has a low degree of automation; (3) the temperature distribution in the dispersion barrel is uneven, the product quality is unstable, and there is a large difference between batches.

[0004] Reaction process intensification and continuous production can solve the bottleneck problems existing in traditional batch production. Patent CN108017771A uses high-gravity emulsification technology to greatly enhance the micro-mixing and mass transfer process, and the resulting water-based polyurethane particles are relatively small. However, high-gravity emulsification technology has high requirements for equipment and is difficult to operate, making it difficult to apply on a large scale. Patent CN109824913B uses a tubular disperser to establish a continuous dispersion system, which can achieve continuous and rapid dispersion of polyurethane prepolymers. However, the internal components of this equipment are complex and difficult to process and install, which is not conducive to industrial scale-up production.

[0005] A microreactor is an equipment-enhancing technology with advantages such as fast mass and heat transfer, efficient mixing, easy process control, and good safety. However, in the preparation of emulsions, micron-sized droplets with uniform particle size are easily produced in the microreactor, but it is difficult to produce nano-sized emulsion droplets due to flow limitations (low Reynolds number and low energy density). Ultrasonic emulsification breaks up droplets through the violent vibration of cavitation bubbles and the accompanying shock waves and microjets, which can more easily produce nanoemulsions. However, due to the uneven distribution of the acoustic field, the particle size of the prepared emulsion is usually unevenly distributed. Utility Model Content

[0006] In response to the above-mentioned shortcomings, the purpose of the present utility model is to provide an ultrasonic microreactor, which, under the synergistic effect of ultrasound and microreactor, has higher energy density and more precise sound field and flow field control capabilities, while also solving problems such as easy channel clogging. Therefore, it is possible to continuously prepare nanoemulsions with uniform particle size, improve the efficiency of the emulsification process and the quality of the emulsion product.

[0007] To this end, the technical solution provided by the present invention is as follows:

[0008] An ultrasonic microreactor is formed by directly bonding an ultrasonic transducer to a microreactor; the ultrasonic microreactor is composed of several layers of fluid microchannel reaction layers connected in series; the fluid microchannel reaction layers are formed by alternating several fine channels and coarse channels; a reaction layer spoiler chip is provided in the middle of the coarse channel.

[0009] Furthermore, in the above-mentioned ultrasonic microreactor, the fluid microchannel reaction layer includes fluid reaction channels with a serpentine layout.

[0010] Furthermore, in the ultrasonic microreactor, a heat exchange layer is provided between two adjacent fluid microchannel reaction layers.

[0011] Furthermore, in the above-mentioned ultrasonic microreactor, the heat exchange layer is provided with a serpentine-shaped heat exchange layer etching channel; and a tubular heat exchange layer spoiler chip is provided in the heat layer etching channel.

[0012] Furthermore, in the above ultrasonic microreactor, a top cover layer is provided on the heat exchange layer.

[0013] Furthermore, the ultrasonic microreactor comprises a fluid microchannel reaction layer, a heat exchange layer and a top cover layer, wherein the fluid microchannel reaction layer is provided with a serpentine-shaped fluid reaction channel; the heat exchange layer is provided with a serpentine-shaped heat exchange layer etching channel;

[0014] The fluid reaction channel is formed by alternately connecting a number of fine channels and thick channels; a reaction layer spoiler chip is provided in the middle of the thick channel.

[0015] Furthermore, in the above-mentioned ultrasonic microreactor, the reaction layer spoiler chip has a structure that is thick at both ends and thin in the middle; the end of the reaction layer spoiler chip facing the fluid input is provided with an inner concave portion with an arc of 100 to 140°; the concave direction of the inner concave portion is opposite to the flow direction of the fluid; and a tubular heat exchange layer spoiler chip is provided in the heat exchange layer etching channel.

[0016] Furthermore, in the above-mentioned ultrasonic microreactor, the cross-sectional diameter ratio of the thin channel and the thick channel is 1:2~3; the cross-sectional diameter of the widest position of the spoiler chip of the thin channel and the thick channel is 1.3~1.7 times the cross-sectional diameter of the thin channel; the cross-sectional diameter of the narrowest position of the spoiler chip is 0.9~1.1 times the cross-sectional diameter of the thin channel; the diameter of the inner concave portion of the spoiler chip is 0.6~0.9 times the cross-sectional diameter of the thin channel.

[0017] Furthermore, in the ultrasonic microreactor, the fluid microchannel inlet port of the fluid microchannel reaction layer is provided with a first feed port and a second feed port; the other port is provided with a discharge port;

[0018] The top cover layer is provided with a first material input pipe installation hole for the cover layer and a second material input pipe installation hole for the cover layer; the heat exchange layer is provided with a first material input pipe installation hole for the heat exchange layer and a second material pipe installation hole for the heat exchange layer;

[0019] The top cover plate layer is provided with a cover plate layer material output pipeline installation hole, and the heat exchange layer is provided with a heat exchange layer material output pipeline installation hole.

[0020] Furthermore, in the above-mentioned ultrasonic microreactor, the frequency of the ultrasonic transducer is 10kHz-300kHz, and the power of the ultrasonic transducer is 20W-300W.

[0021] This application has at least the following beneficial effects:

[0022] 1. The structural turbulence chip and more dense ultrasonic field provided by the utility model can improve the emulsification effect. At the same time, the ultrasonic microreactor also has a strong heat exchange capacity and can effectively control the temperature. By precisely controlling the reaction conditions, such as ultrasonic power, frequency, time and temperature, the particle size distribution and performance of the emulsion can be flexibly adjusted to meet the application needs of different fields.

[0023] 2. The ultrasonic microreactor provided by the utility model realizes the rapid and uniform preparation of aqueous polyurethane nanoemulsion, significantly improves the particle size uniformity and stability of the emulsion, is conducive to industrial scale-up, and has good industrial application prospects.

[0024] 3. The aqueous polyurethane nanoemulsion prepared by the ultrasonic microreactor provided by the utility model has the advantages of small particle size, good dispersibility, narrow particle size distribution, and high stability, and has broad application prospects in the fields of coatings, adhesives, textiles, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an exploded view of the ultrasonic microreactor provided by the utility model;

[0026] Figure 2 This is a schematic structural diagram of the fluid microchannel reaction layer of the ultrasonic microreactor provided by the present invention;

[0027] Figure 3 This is a schematic structural diagram of the fluid microchannel of the ultrasonic microreactor provided by the present invention;

[0028] Figure 4 This is a schematic structural diagram of the heat exchange layer of the ultrasonic microreactor provided by the present utility model;

[0029] Figure 5 This is a schematic structural diagram of the top cover layer of the ultrasonic microreactor provided by the present invention;

[0030] Figure 6 It is a three-dimensional diagram of the static mixer provided by the utility model;

[0031] Figure 7 It is a structural schematic diagram of the static mixer provided by the utility model;

[0032] The symbols in the figure represent the components and similar components as follows:

[0033] Microreactor 1; fluid microchannel reaction layer 11; thin channel 111, coarse channel 112, reaction layer spoiler chip 113; inner recess 114; first feed port 115, second feed port 116, discharge port 117; heat exchange layer 12; heat exchange layer etched channel 122, tubular heat exchange layer spoiler chip 123; heat exchange layer first material input pipeline mounting hole 124, heat exchange layer second material pipeline mounting hole 125, heat exchange layer material output pipeline mounting hole 126; top cover layer 13; cover layer first material input pipeline mounting hole 131; cover layer second material pipeline mounting hole 132; cover layer material output pipeline mounting hole 133; tube body 41; inner core 42.

[0034] Specific embodiment

[0035] The present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. In the description of the present invention, it should be noted that the reagents or instruments used without indicating the manufacturer are conventional products that can be purchased on the market.

[0036] The equipment and components not particularly emphasized in the present invention are all conventional equipment and components in the art.

[0037] Example 1

[0038] The structure of the ultrasonic microreactor described in this Example 1 can be referred to Figures 2 to 6; It is composed of a microreactor 1 and an ultrasonic transducer 2 directly bonded together, wherein the microreactor 1 includes a fluid microchannel reaction layer 11, a heat exchange layer 12 and a top cover layer 13, the microchannel reaction layer 11, the heat exchange layer 12 and the top cover layer 13 are connected by screws, and a first sealing ring 14 is provided between the fluid microchannel reaction layer 11 and the heat exchange layer 12; a second sealing layer ring 15 is provided between the heat exchange layer 12 and the top cover layer 13; ensuring that the layers are tightly connected.

[0039] The fluid microchannel reaction layer 11 is provided with a fluid reaction channel with a serpentine layout; the heat exchange layer 12 is provided with a heat exchange layer etching channel 122 with a serpentine layout, and the heat layer etching channel 122 is provided with a tubular heat exchange layer spoiler chip 123; and a top cover layer 13.

[0040] The fluid reaction channel is formed by alternating several thin channels 111 and thick channels 112. The cross-sectional diameter of the thick channel 112 is larger than that of the thin channel 111. A reaction layer spoiler chip 113 is provided in the middle of the thick channel 112. The spoiler chip 113 has a bullet-shaped structure with thin ends and a thick middle. The end of the spoiler chip 113 facing the fluid input is provided with an inner recess 114. The recessed direction of the inner recess 114 is opposite to the flow direction of the fluid. The cross-sections of the thin channel 111 and the thick channel 112 are circular; the ratio of the cross-sectional diameters of the thin channel 111 and the thick channel is 1:2.5; the cross-sectional diameter of the widest position of the spoiler chip is 1.5 times the cross-sectional diameter of the thin channel 111, the cross-sectional diameter of the narrowest position of the spoiler chip is 1 times the cross-sectional diameter of the thin channel 111, the diameter of the inner concave portion of the spoiler chip is 0.8 times the width of the thin channel 111, and the curvature of the inner concave portion of the spoiler chip is 120°; the cross-sectional diameter of the thin channel 111 is 2 mm.

[0041] Furthermore, the fluid microchannel inlet port of the fluid microchannel reaction layer 11 is provided with a first feed port 115 and a second feed port 116; the other port is provided with a discharge port 117;

[0042] The top cover layer 13 is provided with a first material input pipeline installation hole 131 and a second material input pipeline installation hole 132 for the cover layer; the heat exchange layer 12 is provided with a first material input pipeline installation hole 124 and a second material pipeline installation hole 125 for the heat exchange layer.

[0043] The first material conveying pipe is connected to the first feed port 115 arranged on the fluid microchannel reaction layer 11 through the first material input pipe installation hole 131 of the cover layer and the first material input pipe installation hole 124 of the heat exchange layer. The second material conveying pipe is connected to the second feed port 116 arranged in the fluid reaction channel through the second material input pipe installation hole 132 of the cover layer and the second material pipe installation hole 125 of the heat exchange layer.

[0044] The top cover layer 13 is provided with a cover layer material output pipeline installation hole 133, and the heat exchange layer 12 is provided with a heat exchange layer material output pipeline installation hole 126; the material output pipeline is connected to the discharge port 117 through the cover layer material output pipeline installation hole 133 and the heat exchange layer material output pipeline installation hole 126.

[0045] The static mixer is Figure 6 and 7 , including a tube body 41 and an inner core 42 arranged in the tube body; the inner core and the tube body constitute a mixing channel; the inner core is SX type, with an outer diameter of 10 mm and a length of 10 cm.

[0046] The method for preparing an aqueous polyurethane nanoemulsion using the above-mentioned system for preparing an aqueous polyurethane nanoemulsion through an ultrasonic microreactor comprises the following steps in sequence:

[0047] 1) 54.6 g of isophorone diisocyanate, 100 g of polypropylene glycol (Mn=2000), and 0.2 g of stannous octoate were mixed in a prepolymer reactor 1 and reacted at 80° C. for 1.5 h. Subsequently, 8.33 g of dimethylolpropionic acid and 3.73 g of 1,4-butanediol were added and reacted at 85° C. for 2 h. The mixture was then cooled to 50° C., 25 g of N,N-dimethylformamide was added to reduce the viscosity of the system, and finally 6.29 g of triethylamine was added for neutralization for 20 min to obtain a polyurethane prepolymer;

[0048] 2) The polyurethane prepolymer prepared in step 1) and deionized water were respectively introduced into a static mixer 3 through metering pumps A and B for pre-emulsification to obtain a pre-emulsion, wherein the mass flow rates of the polyurethane prepolymer and deionized water were 5.86 g / min and 9.84 g / min, respectively, the pre-emulsification temperature was 20° C., and the residence time was 30 s;

[0049] 3) The secondary chain extender mixed solution is introduced into the ultrasonic microreactor 4 through the metering pump C at a mass flow rate of 0.9 g / min. The mixed solution and the pre-emulsion are subjected to secondary chain extension and secondary emulsification in the ultrasonic microreactor 4 at 20° C., an ultrasonic frequency of 20 kHz, an ultrasonic power of 50 W, and a residence time of 30 s to finally obtain an aqueous polyurethane dispersion;

[0050] in:

[0051] The mass ratio of deionized water to the secondary chain extender in the mixed solution is 10:1, and hydrazine hydrate is selected as the secondary chain extender.

[0052] The mass flow ratio between the deionized water and the polyurethane prepolymer in the secondary chain extender mixed solution is 2:1.

[0053] After the dispersion in Example 1 was dried and formed into a film, infrared spectroscopy was performed. The spectrum showed that NH (3322 cm -1 )、C=O(1701cm -1 ) and CO(1100cm -1 and 1236cm -1 ) has a strong vibration peak, while at 2275cm -1 No characteristic peak of -NCO was observed, which proved that the waterborne polyurethane was successfully synthesized.

[0054] The dispersions of the above-mentioned examples and comparative examples were tested, and the emulsion particle size was 30 DS / nm and the particle size polydispersity index was 0.088 PDI. It can be seen that the liquid prepared by the equipment provided by the utility model has a smaller dispersion index and a relatively small particle size. By utilizing the unique advantages of the ultrasonic microreactor, the rapid and uniform preparation of waterborne polyurethane nanoemulsion is achieved, and the particle size uniformity and stability of the emulsion are significantly improved, which is conducive to industrial scale-up and has good industrial application prospects.

Claims

1. An ultrasonic microreactor, characterized in that It is formed by directly bonding an ultrasonic transducer to a microreactor; the ultrasonic microreactor is composed of several layers of fluid microchannel reaction layers connected in series; the fluid microchannel reaction layer is formed by alternating several fine channels and coarse channels; a reaction layer spoiler chip is provided in the middle of the coarse channel.

2. The ultrasonic microreactor according to claim 1, characterized in that The fluid microchannel reaction layer includes fluid reaction channels with a serpentine layout.

3. The ultrasonic microreactor according to claim 1, characterized in that A heat exchange layer is provided between two adjacent fluid microchannel reaction layers.

4. The ultrasonic microreactor according to claim 3, characterized in that The heat exchange layer is provided with a serpentine-shaped heat exchange layer etching channel; and a tubular heat exchange layer spoiler chip is provided in the heat layer etching channel.

5. The ultrasonic microreactor according to claim 3, characterized in that A top cover layer is also provided on the heat exchange layer.

6. The ultrasonic microreactor according to claim 5, characterized in that: The microreactor comprises a fluid microchannel reaction layer, a heat exchange layer and a top cover layer. The fluid microchannel reaction layer is provided with a serpentine layout of fluid reaction channels; the heat exchange layer is provided with a serpentine layout of heat exchange layer etching channels; The fluid reaction channel is formed by alternately connecting a number of fine channels and thick channels; a reaction layer spoiler chip is provided in the middle of the thick channel.

7. The ultrasonic microreactor according to claim 6, characterized in that The reaction layer spoiler chip is a bullet-shaped structure with thin ends and a thick middle; the end of the reaction layer spoiler chip facing the fluid input is provided with an inner concave portion with an arc of 100 to 140 degrees; the concave direction of the inner concave portion is opposite to the flow direction of the fluid; a tubular heat exchange layer spoiler chip is provided in the heat exchange layer etching channel.

8. The ultrasonic microreactor according to claim 6, characterized in that The cross-sectional diameter ratio of the thin channel and the thick channel is 1:2-3; the cross-sectional diameter of the widest position of the spoiler chip of the thin channel and the thick channel is 1.3-1.7 times the cross-sectional diameter of the thin channel; the cross-sectional diameter of the narrowest position of the spoiler chip is 0.9-1.1 times the cross-sectional diameter of the thin channel; the diameter of the inner concave portion of the spoiler chip is 0.6-0.9 times the cross-sectional diameter of the thin channel.

9. The ultrasonic microreactor according to claim 6, characterized in that: The fluid microchannel inlet port of the fluid microchannel reaction layer is provided with a first feed port and a second feed port; the other port is provided with a discharge port; The top cover layer is provided with a first material input pipe installation hole for the cover layer and a second material input pipe installation hole for the cover layer; the heat exchange layer is provided with a first material input pipe installation hole for the heat exchange layer and a second material pipe installation hole for the heat exchange layer; The top cover plate layer is provided with a cover plate layer material output pipeline installation hole, and the heat exchange layer is provided with a heat exchange layer material output pipeline installation hole.

10. The ultrasonic microreactor according to claim 1, characterized in that: The frequency of the ultrasonic transducer is 10kHz-300kHz, and the power of the ultrasonic transducer is 20W-300W.

Images