CN112403417A

CN112403417A - Pipeline ultrasonic reactor

Info

Publication number: CN112403417A
Application number: CN202011185116.9A
Authority: CN
Inventors: 黄颖; 张军科; 范晓梅; 张琳
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2021-02-26

Abstract

The invention relates to the technical field of ultrasonic reaction equipment, and discloses a pipeline ultrasonic reactor which comprises a fluid pipeline and an ultrasonic generating mechanism, wherein the ultrasonic generating mechanism is arranged outside the fluid pipeline, a rough surface for adsorbing bubble nuclei is arranged on the inner wall of the fluid pipeline, the roughness Ra of the rough surface is 1-200 um, the ultrasonic frequency f generated by the ultrasonic generating mechanism is 10-1000 kHz, and the product of the roughness of the rough surface and the ultrasonic frequency generated by the ultrasonic generating mechanism is 0.01-100 mm & kHz. The inner wall of the fluid pipeline is provided with a rough surface, the roughness Ra of the rough surface is 1-200 um, the rough surface under the roughness is easy to adsorb and bind a large number of tiny bubble cores, the bubble cores form a large number of cavitation bubbles under the action of ultrasound, so that the ultrasonic mixing effect is enhanced, meanwhile, the friction surface is formed on the inner wall of the fluid pipeline, the situation that fillers are placed in the fluid pipeline is avoided, the pressure drop caused by the complexity of the internal structure of the fluid pipeline cannot be increased, and the blockage of fluid in the fluid pipeline is avoided.

Description

Pipeline ultrasonic reactor

Technical Field

The invention relates to the technical field of ultrasonic reaction equipment, in particular to a pipeline ultrasonic reactor.

Background

The continuous reactor based on the micro-pipeline is widely applied to the field of synthesis of fine chemicals and medical materials due to the advantages of high heat and mass transfer speed, controllable multiphase circulation, safe process, low equipment cost, simple operation, rapid amplification and the like, but the tubular reactors also have the problems of weak convective mixing, easy blockage by solids and the like, particularly under the conditions of low flow velocity ratio and no turbulent flow in the flow state.

In order to enhance the mixing of the fluid in the pipeline, it is common to provide some mixing structures in the pipeline, such as bending and deforming the pipeline, or arranging static mixing members, baffles, etc. in the pipeline, and these mixing structures can cut the fluid or generate local vortex when the fluid passes through, so as to achieve the effect of enhancing the mixing of the fluid. This mixing method is commonly referred to as passive mixing, but it has several disadvantages, firstly, the tiny ducts themselves are easily clogged by solid particles, and the provision of these mixing structures further increases the risk of duct clogging; secondly, the mixing method is extremely dependent on the flow rate of the fluid, and has a good mixing effect only when the flow rate is high, so that the mixing method has poor operation elasticity and a narrow operation window, and is not beneficial to a process with long fluid retention time.

The active mixer strengthens the fluid mixing in the pipeline through the external field, the mixing effect is mainly determined by the strength of the external field and does not depend on the flow velocity of the fluid, so the fluid mixing effect and the retention time can be separately adjusted, the operation interval is large, the elasticity is good, and the active mixer is suitable for low-flow-velocity or high-flow-velocity operation. Among the various active mixers, the ultrasonic-based tubular mixer is most promising because ultrasound is a mechanical wave, safe and reliable; meanwhile, equipment such as an ultrasonic cleaning machine and the like is large-scale and practical in the industry, and the equipment for generating the ultrasonic waves is mature in technology and low in cost. At present, a plurality of patents disclose ultrasonic tubular reactor devices with different structures, such as chinese patent 201410103187.8, world patents WO2011023761, WO2017144720a1 and german patent DE10243837a1, which have been widely used in the industries of chemical industry, food, medicine and the like to enhance the mixing and dispersion of fluids.

The principle of ultrasonic intensified fluid mixing is that under the action of ultrasonic, small bubbles dissolved in fluid in a pipeline or bubble nuclei adhered to the wall of the pipeline grow to form cavitation bubbles, and the cavitation bubbles violently vibrate and jump in the pipeline and generate strong disturbance and vortex like a stirrer, so that the fluid is quickly mixed. However, since the number of bubble nuclei dissolved in the fluid and adhered to the wall of the tube is limited, so that fewer cavitation bubbles are generated under the action of the ultrasonic waves, the mixing effect still has room for further improvement. The mixing time of the fluids under the action of ultrasound (the time required to mix two different fluids uniformly) in a 1mm pipe is 0.2-1 s, two orders of magnitude faster than the mixing time without ultrasound (20-30 s). However, mixing times of 0.2-1 s still do not meet the requirements of rapid chemical reactions, such as precipitation, nitration, radical reactions, etc., with reaction times on the order of 10-100 ms, which require mixing times of the fluid on the order of magnitude or less, which cannot be met by existing ultrasonic mixing methods.

To further enhance the mixing effect of ultrasound on the fluid in the pipeline, chinese patent 201410102972.1 introduces gas through one or more inlets in the pipeline, forming a large number of bubbles with uniform size in the pipeline, which generate the same oscillation and mixing effect as cavitation bubbles under the action of ultrasound. However, at common ultrasonic frequency ranges (20-200 kHz), the bubble size that produces significant ultrasonic cavitation effects is in the 10-300 um range. It is not easy to generate such small bubbles in the pipe.

Chinese patent 202010516802.3 discloses that porous solid filler is placed in a pipeline, and under the action of ultrasound, small bubble nuclei adhered to the surface of the solid filler form cavitation bubbles under the action of ultrasound, so that the quantity and mixing effect of ultrasonic cavitation bubbles are increased. Although this method works very well, the placement of the solid packing in the tubes increases the complexity of the tube structure and increases the pressure drop of the fluid flowing through the tubes, risking plugging of the reactor with smaller tube diameters.

Disclosure of Invention

The purpose of the invention is: a pipeline ultrasonic reactor is provided to improve the ultrasonic mixing effect in an ultrasonic reaction device.

In order to achieve the above object, the present invention provides a pipeline ultrasonic reactor, comprising a fluid pipeline and an ultrasonic generating mechanism, wherein the ultrasonic generating mechanism is arranged outside the fluid pipeline, a rough surface for adsorbing bubble nuclei is arranged on the inner wall of the fluid pipeline, the roughness Ra of the rough surface is 1-200 um, the ultrasonic frequency f generated by the ultrasonic generating mechanism is 10-1000 kHz, and the product of the roughness of the rough surface and the ultrasonic frequency generated by the ultrasonic generating mechanism is 0.01-100 mm-kHz.

Preferably, the product of the roughness of the rough surface and the ultrasonic frequency generated by the ultrasonic generating mechanism is 0.2-30 mm · kHz.

Preferably, the ultrasonic frequency f generated by the ultrasonic generating mechanism is 18-500 kHz.

Preferably, the roughness Ra of the rough surface is 10-100 um.

Preferably, the rough surface is arranged in plurality at intervals on the inner wall surface of the fluid pipeline.

Preferably, the ratio of the equivalent diameter of each roughened surface to the diameter of the fluid conduit is from 0.01 to 1000.

Preferably, the ratio of the interval between two adjacent rough surfaces to the diameter of the fluid pipeline is 0.1-1000.

Preferably, the hydraulic diameter of the fluid conduit is 0.1-100 mm.

Compared with the prior art, the pipeline ultrasonic reactor has the beneficial effects that: the inner wall of the fluid pipeline is provided with a rough surface, the roughness Ra of the rough surface is 1-200 um, the rough surface under the roughness is easy to adsorb and restrict a large number of tiny bubble nuclei, when fluid mixing is carried out by ultrasonic waves with the frequency f of 10-1000 kHz generated by an ultrasonic generating mechanism, the bubble nuclei form a large number of cavitation bubbles under the action of the ultrasonic waves, so that the ultrasonic mixing effect is enhanced, meanwhile, the friction surface is formed on the inner wall of the fluid pipeline, the situation that fillers are placed in the fluid pipeline is avoided, the pressure drop caused by the complexity of the internal structure of the fluid pipeline cannot be increased, and the blockage of the fluid in the fluid pipeline is avoided.

Drawings

FIG. 1 is a schematic structural view of a pipe ultrasonic reactor of the present invention;

FIG. 2 is a side view of the pipe ultrasound reactor of FIG. 1.

In the figure, 1, a fluid pipeline; 2. an ultrasonic generating mechanism; 3. rough surface.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

A preferred embodiment of the pipe ultrasonic reactor of the present invention, as shown in fig. 1 and 2, comprises an ultrasonic generating means 2 and a fluid pipe 1, wherein the ultrasonic generating means 2 is fixed on the outer wall of the fluid pipe 1, and the ultrasonic generating means 2 is used for generating ultrasonic waves and transmitting the ultrasonic waves into the fluid in the fluid pipe 1 through the outer wall of the fluid pipe 1. In the present embodiment, the ultrasonic generating mechanism 2 may be any one of a piezoelectric ceramic, a sandwich piezoelectric transducer, and an electrostatic transducer (capacitive transducer).

The fluid pipeline 1 is a place where the fluid is ultrasonically mixed, and the cross section of the fluid pipeline 1 can be circular, oval or rectangular, or can be other irregular shapes, preferably circular. The material of the fluid pipeline 1 can be metal pipe, glass pipe, ceramic pipe, polymer plastic pipe, preferably glass pipe and metal pipe. The hydraulic diameter of the fluid conduit 1 is 0.1-100 mm, in this embodiment the hydraulic diameter of the fluid conduit 1 is preferably 0.1-100 mm.

The inner wall surface of the fluid pipeline 1 is provided with rough surfaces 3 for adsorbing bubble nuclei, the roughness Ra of the rough surfaces 3 is 1-200 um, in the embodiment, the roughness Ra of the rough surfaces 3 is preferably 10-100 um, the rough surfaces 3 under the roughness have the strongest capacity of adsorbing and binding tiny bubble nuclei, and the size of the formed bubble nuclei can generate obvious ultrasonic cavitation effect. The rough surface 3 on the inner wall of the fluid pipe 1 may be formed when the fluid pipe 1 is processed, or may be formed by grinding the pipe wall after the fluid pipe 1 is processed.

The ultrasonic frequency f generated by the ultrasonic generating mechanism 2 is 10-1000 kHz, and in the embodiment, the ultrasonic frequency f generated by the ultrasonic generating mechanism 2 is preferably 18-500 kHz. The roughness of the rough surface 3 has a matching relation with the ultrasonic frequency generated by the ultrasonic generating mechanism 2, the product of the roughness Ra of the rough surface 3 and the ultrasonic frequency f is 0.01-100 mm.kHz, in the embodiment, the product of the roughness Ra of the rough surface 3 and the ultrasonic frequency f is preferably 0.2-30 mm.kHz; when the roughness Ra of the rough surface 3 and the ultrasonic frequency f satisfy this condition, the effect of the ultrasonic wave and the bubble oscillation and mixing is best.

The rough surface 3 may occupy the entire pipe wall or a part of the pipe wall in the length direction of the fluid pipe 1, and may occupy all or a part of the pipes in the circumferential direction of the cross section of the fluid pipe 1. The rough surface 3 may be the entire inner wall surface of the fluid conduit 1, and the greater the proportion of the rough surface 3 occupying the inner wall surface of the fluid conduit 1, the better the effect of ultrasonic mixing.

In the present embodiment, the rough surfaces 3 are arranged on the inner wall surface of the fluid conduit 1 at intervals, that is, the rough surfaces 3 are arranged at intervals in the axial direction and the circumferential direction of the fluid conduit 1, and the ratio of the equivalent diameter of each rough surface 3 to the diameter of the fluid conduit 1 is 0.01 to 1000, and preferably, the ratio of the equivalent diameter of each rough surface 3 to the diameter of the fluid conduit 1 is 0.1 to 10. The ratio of the interval between two adjacent rough surfaces 3 to the diameter of the fluid pipeline 1 is 0.1-1000, and preferably, the ratio of the interval between two adjacent rough surfaces 3 to the diameter of the fluid pipeline 1 is 1-100.

To sum up, the embodiment of the present invention provides a pipeline ultrasonic reactor, wherein a rough surface is arranged on an inner wall of a fluid pipeline, the roughness Ra of the rough surface is 1-200 um, the rough surface under the roughness is very easy to adsorb and bind a large amount of tiny bubble nuclei, when ultrasonic waves with the frequency f of 10-1000 kHz generated by an ultrasonic generating mechanism are used for fluid mixing, the bubble nuclei form a large amount of cavitation bubbles under the ultrasonic action, so that the ultrasonic mixing effect is enhanced, meanwhile, a friction surface is formed on the inner wall of the fluid pipeline, a filler is prevented from being placed in the fluid pipeline, the pressure drop caused by the complexity of the internal structure of the fluid pipeline is not increased, and the fluid is prevented from being blocked in the fluid pipeline.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. The pipeline ultrasonic reactor is characterized by comprising a fluid pipeline and an ultrasonic generating mechanism, wherein the ultrasonic generating mechanism is arranged outside the fluid pipeline, a rough surface used for adsorbing bubble nuclei is arranged on the inner wall of the fluid pipeline, the roughness Ra of the rough surface is 1-200 um, the ultrasonic frequency f generated by the ultrasonic generating mechanism is 10-1000 kHz, and the product of the roughness of the rough surface and the ultrasonic frequency generated by the ultrasonic generating mechanism is 0.01-100 mm-kHz.

2. The pipe ultrasound reactor of claim 1, wherein the roughness of the roughened surface multiplied by the ultrasound frequency generated by the ultrasound generating means is between 0.2 and 30 mm-kHz.

3. The pipe ultrasonic reactor of claim 1, wherein the ultrasonic frequency f generated by the ultrasonic generating mechanism is 18-500 kHz.

4. The pipe ultrasonic reactor of claim 1, wherein the rough surface has a roughness Ra of 10-100 um.

5. The tubular ultrasonic reactor according to any one of claims 1 to 4, wherein the roughened surface is provided in a plurality of spaced-apart positions on an inner wall surface of the fluid tubular.

6. The tubular ultrasonic reactor of claim 5, wherein the ratio of the equivalent diameter of each roughened surface to the diameter of the fluid tubular is from 0.01 to 1000.

7. The tubular ultrasonic reactor of claim 5, wherein the ratio of the spacing between adjacent asperities to the diameter of the fluid conduit is from 0.1 to 1000.

8. The pipe ultrasound reactor according to any of claims 1 to 4, wherein the hydraulic diameter of the fluid pipe is 0.1 to 100 mm.