Concentric shaft type micro mixer and mixing method

Abstract

The invention belongs to the technical field of micro mixers, and particularly relates to a concentric shaft type micro mixer and a mixing method. The miniature mixer comprises a first liquid inlet channel, a second liquid inlet channel and a liquid outlet channel, the first liquid inlet channel and the liquid outlet channel are concentrically arranged, and the second liquid inlet channel is connected to the joint of the first liquid inlet channel and the liquid outlet channel; the inner diameter of the first liquid inlet channel is smaller than that of the second liquid inlet channel and that of the liquid outlet channel. According to the embodiment of the invention, materials can be fully mixed, continuous production conditions in the precipitation process are provided, and blockage in the precipitation and crystallization process is avoided due to the concentric shaft design. The mixing effect is better than that of a traditional paddle stirrer, and the paddle stirrer is free of control units and easily-damaged parts and suitable for special systems such as strong acid liquid.

Description

Technical Field

[0001] The present application belongs to the technical field of micro mixers, and in particular relates to a coaxial micro mixer and a mixing method. Background Art

[0002] Precipitation is a common unit operation in the chemical industry. Through precipitation unit operation, both liquid purification and material transformation can be achieved. It is widely used in metal preparation, purification, water treatment and other industries. Stirring plays a key role in the precipitation process, which makes the precipitant and the precipitation stock solution evenly mixed, and has a direct impact on the purification of the material.

[0003] Involving high-concentration nitric acid systems, the agitator is easily corroded and deformed, and the electronic control unit of the agitator is prone to failure, affecting production efficiency. The pore size of the general mixer is 600μm, which can achieve full mixing of the two-phase liquid, but is not suitable for the precipitation process. The solid precipitate produced during the precipitation process is easy to clog the pipeline. Summary of the invention

[0004] The purpose of the present application is to provide a concentric shaft type micro mixer and a mixing method, so as to solve the problem in the prior art that solid sediments generated during the sedimentation process are prone to block the pipeline.

[0005] Technical solution to achieve the purpose of this application:

[0006] In a first aspect, an embodiment of the present application provides a concentric shaft type micro mixer, the micro mixer comprising: a first liquid inlet channel, a second liquid inlet channel and a liquid outlet channel;

[0007] The first liquid inlet channel and the liquid outlet channel are arranged concentrically, and the second liquid inlet channel is connected to the connection between the first liquid inlet channel and the liquid outlet channel;

[0008] Wherein, the inner diameter of the first liquid inlet channel is smaller than the inner diameters of the second liquid inlet channel and the liquid outlet channel.

[0009] Optionally, the second liquid inlet channel is arranged perpendicular to the liquid outlet channel.

[0010] Optionally, the inner diameter of the first liquid inlet channel is 1 mm, the inner diameter of the second liquid inlet channel is 3 mm, and the inner diameter of the liquid outlet channel is 3 mm.

[0011] Optionally, the first liquid inlet channel is used to introduce the stock solution, and the second liquid inlet channel is used to introduce the precipitant.

[0012] Optionally, the micro mixer is a split structure.

[0013] The second aspect of the embodiment of the present application provides a mixing method, which is applied to any one of the concentric shaft micro mixers provided in the first aspect of the embodiment of the present application; the method comprises:

[0014] The stock solution is introduced into the first liquid inlet channel, and the precipitant is introduced into the second liquid inlet channel;

[0015] The precipitation reaction results are collected at the outlet channel.

[0016] Optionally, the precipitant is hydrogen peroxide.

[0017] Optionally, the concentration of the uranyl nitrate is 100.35 gU / L, and the acidity is 1.13 mol / L; the precipitant is 30% hydrogen peroxide, M(H2O2):M(U)=8.18:1.

[0018] The beneficial technical effects of this application are:

[0019] The embodiment of the present application provides a concentric shaft type micro mixer and a mixing method, wherein the micro mixer comprises: a first liquid inlet channel, a second liquid inlet channel and a liquid outlet channel; the first liquid inlet channel and the liquid outlet channel are concentrically arranged, and the second liquid inlet channel is connected to the connection between the first liquid inlet channel and the liquid outlet channel; wherein the inner diameter of the first liquid inlet channel is smaller than the inner diameter of the second liquid inlet channel and the liquid outlet channel. The embodiment of the present application can achieve full mixing of materials, and has the conditions for continuous production during the precipitation process, and the concentric shaft design avoids blockage during the precipitation crystallization process. The mixing effect is stronger than that of the traditional paddle agitator, and there is no control unit and fragile parts, which is suitable for special systems such as strong acid liquid. It has great application prospects in continuous precipitation, because it occupies a very small space and is very suitable for glove box operation in the nuclear chemical industry. The micro mixer can be processed by 3D printing technology, machining technology and etching technology, and can also be processed using a variety of materials, such as Hazardous Materials C, nickel-based alloys, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of the structure of a concentric shaft type micro mixer provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of the application of a concentric shaft micro mixer provided in an embodiment of the present application.

[0022] In the figure:

[0023] 1-first liquid inlet channel; 2-second liquid inlet channel; 3-liquid outlet channel. DETAILED DESCRIPTION

[0024] In order to make those skilled in the art better understand the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only a part of the embodiments of the present application, not all. Based on the embodiments recorded in the present application, all other embodiments obtained by those skilled in the art without paying creative work are within the scope of protection of the present application.

[0025] See also Figure 1 , which is a schematic structural diagram of a concentric shaft type micro mixer provided in an embodiment of the present application.

[0026] A concentric shaft micro mixer provided in an embodiment of the present application comprises: a first liquid inlet channel 1, a second liquid inlet channel 2 and a liquid outlet channel 3;

[0027] The first liquid inlet channel 1 and the liquid outlet channel 3 are arranged concentrically, and the second liquid inlet channel 2 is connected to the connection between the first liquid inlet channel 1 and the liquid outlet channel 3;

[0028] The inner diameter of the first liquid inlet channel 1 is smaller than the inner diameters of the second liquid inlet channel 2 and the liquid outlet channel 3 .

[0029] In a specific implementation, the first liquid inlet channel 1 , the second liquid inlet channel 2 and the liquid outlet channel 3 may all be smooth pipes.

[0030] In one example, the second liquid inlet channel 2 is arranged perpendicular to the liquid outlet channel 3 .

[0031] In some possible implementations of the embodiments of the present application, the inner diameter of the first liquid inlet channel 1 is 1 mm, the inner diameter of the second liquid inlet channel 2 is 3 mm, and the inner diameter of the liquid outlet channel 3 is 3 mm.

[0032] In one example, the first liquid inlet channel 1 is used to introduce the stock solution, and the second liquid inlet channel 2 is used to introduce the precipitant.

[0033] In another example, the micro mixer is a split structure.

[0034] In the embodiment of the present application, in order to adapt to the primary precipitation reaction and avoid the instantaneous blockage of the pores by the precipitate generated after mixing, the internal structure of the micro mixer is designed in a concentric axis confluence manner. Figure 2As shown, the second liquid inlet channel 2 is relatively large in size, allowing a large flow rate to flow through, and is designed as a precipitant flow channel. The first liquid inlet channel 1 is a small-size flow channel, designed as a precipitation stock solution flow channel. The total flow rate is designed to be 120ml / min, and the pipe size is 3mm, which can be calculated to be 0.28m / s. At this flow rate, the precipitant-coated stock solution flows out, and under the condition of the port effect, the stock solution diffuses outward. The precipitant forms a flow gradient under the action of the climbing rod effect, which can achieve full mixing of the materials. For the first-order two-phase precipitation reaction, the precipitation rate of the material after micro-size mixing is greater than 99%, which greatly improves the precipitation efficiency of the material.

[0035] The micro mixer has a very fast precipitation speed and can generate a large amount of precipitation in an extreme time. Due to its extremely short residence time, the impurity elements do not have time to react before the solid-liquid separation is completed, achieving the effect of impurity purification. In specific implementation, the precipitation stock solution and the precipitant with a suitable metering ratio are transported to the micro mixer by a high-pressure plunger pump, and the precipitation reaction is completed after mixing. This process is suitable for primary chemical precipitation reaction, realizing continuous operation of the precipitation process and reducing labor costs.

[0036] A concentric shaft type micro mixer provided in an embodiment of the present application is described in detail below with reference to a specific example.

[0037] A concentric shaft type micro mixer provided in the embodiment of the present application has been verified in the uranium peroxide precipitation process. During the precipitation process, the concentration of uranyl nitrate prepared is 100.35gU / L, the acidity is 1.13mol / L, the precipitant is 30% hydrogen peroxide, M(H2O2):M(U)=8.18:1, and the precipitation process uses a precision high-pressure plunger pump to inject hydrogen peroxide and uranyl nitrate into the A and B ports of the micro mixer in a molar ratio. Under normal temperature (23°C to 25°C), the material mixing occurs precipitation reaction instantly. After precipitation, the tail liquid concentration is sampled and tested, and the calculated precipitation rate is above 99%. If the aging time (5 to 10min) is matched, the precipitation rate reaches 99.98%, which is significantly better than the traditional kettle precipitation and significantly improves the production efficiency. The impurity purification effect of the micro mixer precipitation is significant, as shown in Table 1, which is better than the kettle precipitation process.

[0038] Table 1 Impurity purification table

[0039] Impurity Type Al Fe Ni Cu Zr Cr Stock solution (μg / gU) 1405 4070 856 866 1058 923 Precipitation (μg / gU) 10.7 4.2 0.6 0.7 118.9 0.6 Impurity purification coefficient 131 969 1427 1237 9 1538

[0040] The embodiment of the present application can achieve full mixing of materials and has the conditions for continuous production of the precipitation process. The concentric shaft design avoids blockage in the precipitation crystallization process. The mixing effect is stronger than that of the traditional paddle agitator. It has no control unit and fragile parts and is suitable for special systems such as strong acid liquids. It has great application prospects in continuous precipitation because it occupies very little space and is very suitable for glove box operation in the nuclear chemical industry. The micromixer can be processed by 3D printing technology, machining technology and etching technology, and can also be processed using a variety of materials, such as Ha C, nickel-based alloys, etc.

[0041] Based on the coaxial shaft type micro mixer provided in the above embodiments, the embodiments of the present application further provide a mixing method, which is applied to any one of the coaxial shaft type micro mixers provided in the above embodiments.

[0042] A hybrid method provided in an embodiment of the present application includes:

[0043] Step S101: introducing a stock solution into the first liquid inlet channel 1, and introducing a precipitant into the second liquid inlet channel 2;

[0044] Step S102: collecting precipitation reaction results at the liquid outlet channel 3.

[0045] In one example, the precipitating agent is hydrogen peroxide.

[0046] In another example, the concentration of uranyl nitrate is 100.35 gU / L, and the acidity is 1.13 mol / L; the precipitant is 30% hydrogen peroxide, and M(H2O2):M(U)=8.18:1.

[0047] In the precipitation process, the concentration of uranyl nitrate is 100.35 gU / L, the acidity is 1.13 mol / L, the precipitant is 30% hydrogen peroxide, M(H2O2):M(U)=8.18:1, and a precision high-pressure plunger pump is used to inject hydrogen peroxide and uranyl nitrate into the A and B ports of the micro mixer in a molar ratio. Under the condition of room temperature (23°C-25°C), a precipitation reaction occurs instantly when the materials are mixed. After precipitation, a sample is taken to test the concentration of the tail liquid, and the calculated precipitation rate is above 99%. If the aging time (5-10 minutes) is combined, the precipitation rate reaches 99.98%, which is significantly better than the traditional kettle precipitation and significantly improves the production efficiency.

[0048] The present application is described in detail above in conjunction with the accompanying drawings and embodiments, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present application. Any content not described in detail in the present application can adopt the existing technology.

Claims

1. A concentric shaft micro mixer, characterized in that: The micro mixer comprises: a first liquid inlet channel (1), a second liquid inlet channel (2) and a liquid outlet channel (3); The first liquid inlet channel (1) and the liquid outlet channel (3) are arranged concentrically, and the second liquid inlet channel (2) is connected to the connection between the first liquid inlet channel (1) and the liquid outlet channel (3); The inner diameter of the first liquid inlet channel (1) is smaller than the inner diameters of the second liquid inlet channel (2) and the liquid outlet channel (3).

2. The concentric shaft micro mixer according to claim 1, characterized in that: The second liquid inlet channel (2) is arranged perpendicular to the liquid outlet channel (3).

3. The concentric shaft micro mixer according to claim 1, characterized in that: The inner diameter of the first liquid inlet channel (1) is 1 mm, the inner diameter of the second liquid inlet channel (2) is 3 mm, and the inner diameter of the liquid outlet channel (3) is 3 mm.

4. The concentric shaft micro mixer according to any one of claims 1 to 3, characterized in that: The first liquid inlet channel (1) is used for introducing the stock solution, and the second liquid inlet channel (2) is used for introducing the precipitant.

5. The concentric shaft micro mixer according to any one of claims 1 to 3, characterized in that: The micro mixer is of split structure.

6. A hybrid method, characterized in that The concentric shaft micro mixer according to any one of claims 1 to 5; the method comprising: A stock solution is introduced into the first liquid inlet channel (1), and a precipitant is introduced into the second liquid inlet channel (2); The precipitation reaction results are collected at the liquid outlet channel (3).

7. The mixing method according to claim 6, characterized in that The stock solution is uranyl nitrate, and the precipitant is hydrogen peroxide.

8. The mixing method according to claim 7, characterized in that The concentration of the uranyl nitrate is 100.35 gU / L, and the acidity is 1.13 mol / L; the precipitant is 30% hydrogen peroxide, M(H2O2): M(U)=8.18:1.

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