A supergravity continuous foam separation device and method

Abstract

The present invention discloses a high-gravity continuous foam separation device and method, belonging to the field of chemical separation technology. The device includes n high-gravity rotating packed beds and n+1 foam columns. When n=2, it includes first and second high-gravity rotating packed beds, and first, second, and third foam columns. The gas inlet of the first high-gravity rotating packed bed and the gas inlet of the first foam column are simultaneously connected to a gas delivery pipeline, and the foam outlet of the first foam column is connected to the liquid outlet of the first high-gravity rotating packed bed. The gas inlet of the second foam column is connected to the gas outlet of the first rotating packed bed, and the foam outlet of the second foam column is connected to the gas inlet of the second high-gravity rotating packed bed. The gas inlet of the third foam column is connected to the gas outlet of the second high-gravity rotating packed bed. The liquid inlet of the first rotating packed bed is simultaneously connected to the liquid outlet of the second rotating packed bed and a liquid delivery pipeline. The present invention achieves efficient separation of target substances and is suitable for continuous operation processes.

Description

Technical Field

[0001] The invention relates to a high-gravity continuous foam separation device and method, belonging to the technical field of chemical separation. Background Art

[0002] Foam separation is based on the principle of interfacial chemical adsorption. Using foam or bubbles as a carrier, surface-active components (ions, molecules, colloids, solid particles, or suspended particles) adhere to the rising bubbles and float to the liquid surface, separating surfactant components or components that can bind to surfactants from the solution, thereby purifying the solution. This method offers advantages such as simple equipment, gentle operation, low energy consumption, high efficiency, continuous or intermittent operation, and ease of industrial scale-up. It has been widely used in the metallurgical industry, environmental protection industry, food industry, and bioseparation. However, conventional foam separation processes suffer from large and uneven bubbles, poor stability, slow mass transfer efficiency, and low separation efficiency. Therefore, reducing bubble size, improving bubble morphology, and improving mass transfer and separation efficiency are pressing challenges.

[0003] Chinese patent CN116585757A discloses a foam separation device with an octagonal pyramidal internal component containing sieve holes and its application. This invention purifies and separates β-glucosidase fusion protein by enhancing foam drainage. Experimental results show that this device improves the enrichment ratio, but the recovery rate still needs to be improved. Chinese patent CN103142664A discloses a method for extracting total saponins from Bupleurum chinense using a two-stage foam separation process. This invention involves a continuous foam separation process for total saponins from Bupleurum chinense. The device performs a two-stage foam separation of saponins, and its separation efficiency still has potential and room for improvement. Chinese patent CN115634781A discloses a novel foam separation and purification device with several porous trays with sieve holes added to the foam section. This device was used to extract an aqueous sodium dodecyl sulfate (SDS) solution from surfactant wastewater. Results showed an SDS recovery rate of 97.79% and an enrichment ratio of 1.791. The design of this equipment focused on optimizing the foam drainage process, resulting in the failure to achieve a simultaneous improvement in recovery rate and enrichment ratio, reflecting that the equipment performance still needs to be further balanced and optimized in these two aspects.

[0004] Currently, the two key factors affecting foam separation efficiency are surface adsorption and foam drainage. Throughout the foam separation process, enhancing surface adsorption is crucial for improving separation efficiency. While some existing inventions can improve separation performance to a certain extent by modifying system properties (such as liquid viscosity and surface tension) and optimizing operating conditions (such as the gas-liquid ratio and bubble generation rate), achieving optimal results remains difficult. To address these issues, the present invention proposes a high-gravity continuous foam separation device and method. Summary of the Invention

[0005] In response to the problems existing in the current foam separation technology, such as large bubbles, slow mass transfer efficiency, and low separation efficiency, the present invention provides a high-gravity continuous foam separation device and method.

[0006] The present invention proposes to improve the traditional foam separation equipment. Based on the principle of enhanced separation of gas-liquid two-phase in a hypergravity field, a supergravity continuous foam separation device is invented. Its core device is a rotating packed bed. The centrifugal force field is generated by high-speed rotation to quickly separate the foam and liquid phases. The purpose is to strengthen the surface adsorption process, optimize the generation and rupture process of bubbles, and use the hypergravity field to greatly increase the renewal rate of the gas-liquid interface, significantly improve the mass transfer efficiency and separation effect, and achieve continuous and efficient separation of target substances. The innovation of the present invention is reflected in: 1. Applying supergravity technology to the field of foam separation, providing a supergravity continuous foam separation device; using supergravity technology can greatly enhance the interface adsorption and separation process, and can effectively improve the gas-liquid mass transfer efficiency. The high-speed rotating packing in the hypergravity field generates huge shear force. The liquid is torn into a micro-liquid state after multiple times and quickly contacts with the gas, which accelerates the frequency of gas-liquid surface renewal and the degree of liquid turbulence, increases the effective contact area of ​​the target substance at the gas-liquid interface, and greatly improves the interphase mass transfer rate. ② The present invention introduces two-stage or multi-stage supergravity technology to provide two or more gas-liquid two-phase contact sites, so that the gas-liquid two-phase can be sheared and reorganized multiple times under the action of centrifugal force, greatly accelerating the gas-liquid surface renewal rate, achieving the purpose of strengthening the surface adsorption process, increasing the effective gas-liquid contact area, and significantly improving the separation and purification effect of the target substance.

[0007] The present invention provides a high-gravity continuous foam separation device, comprising n high-gravity rotating packed beds and n+1 foam columns. The present invention is described as follows using n=2 as an example:

[0008] The separation device comprises a first high-gravity rotating packed bed and a second high-gravity rotating packed bed, a first foam column, a second foam column, and a third foam column;

[0009] The gas inlet of the first high-gravity rotating packed bed is connected to the gas inlet of the first foam column and the gas delivery pipeline at the same time, and the foam outlet of the first foam column is connected to the liquid outlet of the first high-gravity rotating packed bed; the gas inlet of the second foam column is connected to the gas outlet of the first high-gravity rotating packed bed, and the foam outlet of the second foam column is connected to the gas inlet of the second high-gravity rotating packed bed; the gas inlet of the third foam column is connected to the gas outlet of the second high-gravity rotating packed bed; the liquid inlet of the first high-gravity rotating packed bed is connected to the liquid outlet of the second high-gravity rotating packed bed and the liquid delivery pipeline at the same time;

[0010] The gas delivery pipeline consists of a fan, a gas buffer tank, a gas valve, and a gas flow meter connected in sequence; the liquid delivery pipeline includes a raw material liquid tank, a pump, a liquid valve, and a liquid flow meter connected in sequence.

[0011] Furthermore, the core components of the first supergravity rotating packed bed and the second supergravity rotating packed bed are the same. The first supergravity rotating packed bed includes a rotor, packing, a shell, a motor, and a liquid distributor. The lower side of the shell is provided with a gas inlet, the top is provided with a liquid inlet and a gas outlet, and the bottom is provided with a liquid outlet; various packings are installed in the rotor, the bottom of the rotor is connected to the motor, and is driven to rotate by the motor; the liquid delivery pipeline sprays the liquid to the inner edge of the packing through the liquid distributor; the structure of the second supergravity rotating packed bed is the same as the above-mentioned structure of the first supergravity rotating packed bed. In addition, the liquid inlet of the second supergravity rotating packed bed is connected to the diverter valve under the defoamer, and the reflux liquid is transported to the inside of the packing through the liquid distributor; a guide tube is provided at the gas inlet of the second supergravity rotating packed bed to prevent excessive liquid from flowing into the second foam column and affecting the rise of bubbles; the liquid outlet of the second supergravity rotating packed bed is provided with a one-way valve, and the liquid that has not been foam-separated continues to enter the first supergravity rotating packed bed;

[0012] Furthermore, the guide tube includes an upper tube and a lower tube, both of which are hollow conical structures, and their outer sides are connected in sequence by multiple drainage baffles with arc-shaped protrusions to form a cylindrical structure. The upper tube and the lower tube are placed at an angle, and the two are combined into a structure that is narrow at both ends and wide in the middle, and the top opening of the upper tube is larger than the bottom opening of the lower tube. Specifically, each drainage baffle occupies 1 / 4 to 1 / 36 of the circumference of the guide tube. Under the action of centrifugal force, when the splashed liquid hits the upper tube, the raised part on the drainage baffle will drain the liquid into the groove between the two drainage baffles and flow along the direction of the groove, so that the originally concentrated fluid is dispersed to different groove directions by the impact force, changing the flow direction of the liquid. The lower tube is used to block the remaining liquid in the packing bed to prevent the liquid from entering the second foam column; under the action of the guide tube, the liquid flows along the liquid outlet into the first supergravity rotating packing bed, which helps to stabilize the operation of the second foam column and prevent liquid impact; the overall height of the guide tube is set according to the size of the supergravity rotating packing bed and the foam column, the height ratio of the upper tube and the lower tube is between 1:2 and 1:10, the upper tube is inclined at an angle of 5° to 85° with the vertical direction, and the lower tube is inclined at an angle of 0° to 85° with the vertical direction.

[0013] Furthermore, the foam column bodies of the first foam column, the second foam column and the third foam column are closed cylindrical; a guide pipe is provided on the side of the third foam column, the outlet of which is connected to the defoamer, and a reflux pipe is provided under the defoamer, and the defoaming liquid flows into the second supergravity rotating packed bed through the reflux pipe; another reflux pipe of the defoamer is connected to the product tank; whether to reflux, as well as the reflux time, number of cycles and reflux flow rate are determined according to the product quality.

[0014] Furthermore, the guide tube structure of the third foam column is an annular tube, which is arranged at an angle downward on the side of the third foam column, with an inclination angle ranging from 10° to 90°, and the outlet end is connected to the defoamer. The defoamer structure is as follows: the body of the device is cylindrical, and an ultrasonic rod is installed on one side of the interior, which extends into the interior to break the foam; a needle-shaped bubble breaker is arranged at the bottom and side, and the needle-shaped bubble breaker is a mace-shaped structure with sharp thorns arranged upward; the ultrasonic rod and the needle-shaped bubble breaker can be used simultaneously or separately, and the size of the needle-shaped bubble breaker is determined according to the size of the defoamer; a liquid level gauge is placed on the top to monitor the foam generation rate and liquid level changes in real time. If the liquid level exceeds the set value, the feed flow rate or operating conditions need to be adjusted to avoid foam overflow due to excessive liquid; a diverter valve is arranged under the defoamer, which can be adjusted manually or automatically through a controller to accurately control the reflux rate of the defoaming liquid;

[0015] Furthermore, a one-way valve is provided below the second high-gravity rotating packed bed to control the one-way flow of the fluid and prevent the liquid from flowing back.

[0016] Furthermore, the liquid outlet on the side of the first foam column is connected to the residual liquid tank.

[0017] Furthermore, the packing of the high-gravity rotating packed bed is at least one or more of a combination of ball ring packing, wire mesh packing, spherical packing, arc saddle packing, and honeycomb packing, and the packing type is interchangeable. Furthermore, the packing is composed of a series of multiple rotating packed beds or a combination of multiple packing layers. A combination of multiple packing layers refers to sequentially arranging packings of the same or different types or specifications to form multiple independent working layers, each layer having different functions and points of action. A series connection of multiple rotating packed beds refers to a multi-stage packing formed by connecting multiple independent rotating packed beds in series, with each rotating packed bed acting as an independent processing unit.

[0018] Furthermore, through the combined design of a rotating packed bed and foam column consisting of multi-stage series or multi-layer packing, as well as an adjustable feed, gas-liquid ratio and reflux system, efficient separation and enrichment of target substances in continuous or semi-continuous mode are achieved; the foam column has a height-to-diameter ratio ranging from 5 to 50 and is designed according to the liquid flow rate and bubble diffusion characteristics to improve the gas-liquid contact efficiency and reduce the equipment pressure drop.

[0019] The present invention provides a high-gravity continuous foam separation method. In the above-mentioned high-gravity continuous foam separation device, the raw material liquid is foamed in the first high-gravity rotating packed bed to generate a foam phase and a liquid phase. The foam phase passes through the gas outlet of the first high-gravity rotating packed bed through the second foam column and enters the second high-gravity rotating packed bed for further foaming. Under the action of the gas, the foam continuously rises and enters the third foam column, and a high-concentration target substance is obtained in the defoamer; the liquid phase in the defoamer is refluxed to the second high-gravity rotating packed bed for continued foaming, and the remaining liquid phase flows into the first high-gravity rotating packed bed for continued foam separation, and the remaining liquid phase component is obtained at the bottom of the first foam column.

[0020] Furthermore, the above-mentioned high-gravity continuous foam separation method specifically comprises the following steps:

[0021] (1) Start the motor and set the rotation speed of the first and second high-gravity rotating packed beds. The raw material liquid is driven by the pump and injected into the first high-gravity rotating packed bed after being measured by the rotor flowmeter. At the same time, start the fan to supply gas to the system. After the gas passes through the buffer tank, the gas velocity is stabilized by adjusting the flowmeter. The gas pipeline is divided into two branches: one pipeline enters the first foam column through the gas distributor and rises to the first high-gravity rotating packed bed; the other pipeline directly enters the first high-gravity rotating packed bed.

[0022] (2) The two gases merge in the first high-gravity rotating packed bed; in the first high-gravity rotating packed bed, the liquid is thrown from the inside of the packing to the outside by the centrifugal force, and contacts with the gas to generate microbubbles; part of the liquid flows into the first foam column through the liquid outlet of the first high-gravity rotating packed bed, and the bubbles formed at this time continue to rise into the first high-gravity rotating packed bed to achieve foam separation;

[0023] (3) The foam enters the second foam column from the gas outlet of the first high-gravity rotating packed bed, and continues to rise to the second high-gravity rotating packed bed for continuous foaming. At the same time, it undergoes the process of foaming, reorganization, crushing and reorganization. The surface is constantly renewed, which effectively improves the material enrichment efficiency. During the rising process of the foam, part of the liquid it carries will flow through the liquid outlet of the second high-gravity rotating packed bed to the first high-gravity rotating packed bed due to gravity for re-circulation and separation.

[0024] (4) The foam in the second foam column rises into the second high-gravity rotating packed bed, continuously foams under the action of gas and rises into the third foam column, and is finally collected in the defoamer through the guide pipe;

[0025] (5) In the defoamer, bubbles are broken by ultrasonic rods or needle-shaped bubble breakers to form defoaming liquid; the liquid level gauge at the top monitors the foam generation rate and liquid level changes in real time; a diverter valve is installed at the bottom of the defoamer to control the diversion ratio of the reflux liquid and the defoaming liquid, so that part of the defoaming liquid flows into the product tank and the other part flows back to the second high-gravity rotating packed bed; after the entire separation process is completed, the product tank collects the product, and the remaining residual liquid is collected by the residual liquid tank.

[0026] In the above method, the gas-liquid contact mode is one of cross-flow, counter-flow or co-flow, the hypergravity factor is 5 to 120; and the gas is at least one or more of air, carbon dioxide, nitrogen, oxygen or inert gas.

[0027] In the above separation method, the reflux ratio of the defoaming liquid, the height of the foam column and the height of the packing are determined according to the foam rising speed, the gas-liquid flow rate and the separation effect; that is, the reflux ratio is controlled by controlling factors such as the gas flow rate, the liquid flow rate, the raw material liquid concentration, and the pH value, and finally the appropriate reflux speed is selected during operation to ensure that this process can be operated continuously or semi-continuously.

[0028] Beneficial effects of the present invention:

[0029] (1) The present invention applies supergravity technology to the field of foam separation, significantly increasing the gas-liquid contact area and achieving efficient adsorption of target substances on the submillimeter microbubble interface. This effectively overcomes the shortcomings of traditional foam separation equipment, such as large and uneven bubbles, low mass transfer efficiency, and low separation efficiency, and achieves efficient separation of target substances.

[0030] (2) The present invention utilizes a supergravity continuous foam separation device to provide a two-stage or multi-stage gas-liquid two-phase contact separation site. Bubble recombination and fragmentation are carried out alternately, and the surface is continuously renewed, which significantly enhances the separation effect, improves the stability and separation efficiency of the foam, and is suitable for continuous operation processes. It is green, efficient, low in energy consumption, and meets the needs of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of the high-gravity continuous foam separation device of the present invention;

[0032] Figure 2 This is a structural diagram of the first foam column in the device of the present invention;

[0033] Figure 3 This is a structural diagram of the second foam column in the device of the present invention;

[0034] Figure 4 This is a structural diagram of the third foam column in the device of the present invention;

[0035] Figure 5 This is a diagram showing the internal structure of the first high-gravity rotating packed bed in the device of the present invention;

[0036] Figure 6 This is a diagram showing the internal structure of the second high-gravity rotating packed bed in the device of the present invention;

[0037] Figure 7 FIG. 1 is a diagram showing the internal structure of the defoamer in the device of the present invention;

[0038] Figure 8 for Figure 7 Top view of the internal structure of the middle defoamer;

[0039] Figure 9 It is a three-dimensional structural diagram of the guide tube of the present invention;

[0040] Figure 10 for Figure 9 Top view of the middle guide tube;

[0041] Figure 11 for Figure 9 Planar side view of the middle guide tube;

[0042] Figure 12 This is a diagram of the internal structure of the rotating packed bed composed of multiple layers of packing in Example 3.

[0043] In the figure: 1. raw liquid storage tank; 2. pump; 3. liquid valve; 4. liquid flow meter; 5. first supergravity rotating packed bed; 6. first motor; 7. fan; 8. gas buffer tank; 9. gas valve; 10. gas flow meter; 11. residual liquid tank; 12. first foam column; 13. second foam column; 14. second supergravity rotating packed bed; 15. second motor; 16. one-way valve; 17. third foam column; 18. liquid level meter; 19. ultrasonic disperser; 20. defoamer; 201. ultrasonic rod; 21. diverter valve; 22. product tank; 1201. gas inlet of first foam column; 1202. residual liquid outlet of first foam column; 1203. foam outlet of first foam column; 1204. gas distributor; 1301. gas inlet of second foam column; 1302. foam outlet of second foam column; 170 1. Gas inlet of the third foam column; 1702. Draft tube; 1703. Foam outlet of the third foam column; 501. Gas inlet; 502. Liquid inlet; 503. Second liquid inlet; 504. Gas outlet; 505. Liquid outlet; 506. Liquid distributor; 507. Packing; 1401. Gas outlet of the second supergravity rotating packed bed; 1402. Liquid inlet of the second supergravity rotating packed bed; 1403. Liquid outlet of the second supergravity rotating packed bed; 1404. Gas inlet of the second supergravity rotating packed bed; 1405. Liquid distributor of the second supergravity rotating packed bed; 1406. Packing of the second supergravity rotating packed bed; 1407. Draft tube; 23. Liquid inlet of the rotating packed bed composed of multiple layers of packing; 24. Honeycomb packing; 25. Pall ring packing; 26. Wire mesh packing. DETAILED DESCRIPTION

[0044] The present invention is further illustrated below by way of examples, but is not limited to the following examples. Example 1

[0045] like Figures 1 to 11 As shown, a supergravity continuous foam separation device includes two supergravity rotating packing beds and three foam columns in this embodiment; specifically, it includes a first supergravity rotating packing bed 5, a second supergravity rotating packing bed 14; a first foam column 12, a second foam column 13, and a third foam column 17; the second foam column 13 connects the first supergravity rotating packing bed 5 with the second supergravity rotating packing bed 14; the first foam column 12 is connected below the first supergravity rotating packing bed 5; and the third foam column 17 is connected above the second supergravity rotating packing bed 14.

[0046] like Figure 1 As shown, the gas inlet 501 of the first supergravity rotating packed bed and the first foam column gas inlet 1201 are connected to the gas delivery pipeline at the same time, and the first foam column foam outlet 1203 is connected to the liquid outlet 505 of the first supergravity rotating packed bed; the second foam column gas inlet 1301 is connected to the gas outlet 504 of the first supergravity rotating packed bed, and the second foam column foam outlet 1302 is connected to the gas inlet 1404 of the second supergravity rotating packed bed; the third foam column gas inlet 1701 is connected to the gas outlet 1401 of the second supergravity rotating packed bed; the liquid inlet 502 of the first supergravity rotating packed bed is connected to the liquid delivery pipeline, and the second liquid inlet 503 is connected to the liquid outlet 1403 of the second supergravity rotating packed bed;

[0047] The gas delivery pipeline consists of a blower 7, a gas buffer tank 8, a gas valve 9 and a gas flow meter 10 connected in sequence;

[0048] The liquid delivery pipeline includes a raw material liquid storage tank 1, a pump 2, a liquid valve 3 and a liquid flow meter 4 which are connected in sequence.

[0049] Furthermore, the first supergravity rotating packed bed 5 includes a rotor, a packing 507, a shell, a first motor 6, and a liquid distributor 506. A gas inlet 501 (connected to a gas delivery pipeline) is provided on the lower side of the shell, a liquid inlet 502, a second liquid inlet 503 and a gas outlet 504 are provided on the top, and a liquid outlet 505 is provided on the bottom; various packings 507 are installed in the rotor, and the bottom of the rotor is connected to the first motor 6 and is driven to rotate by the first motor 6; the gas outlet 504 of the first supergravity rotating packed bed 5 is connected to the second foam column gas inlet 1301, and its liquid outlet 505 is connected to the first foam column foam outlet 1203; the liquid inlet 502 is connected to the liquid delivery pipeline, and the second liquid inlet 503 is connected to the second supergravity rotating packed bed liquid outlet 1403, so that the liquid is transported to the inside of the packing through the liquid distributor 506.

[0050] Furthermore, the internal structure of the second high-gravity rotating packed bed 14 is the same as that of the first high-gravity rotating packed bed 5. The lower side of the shell is provided with a second high-gravity rotating packed bed gas inlet 1404 and a second high-gravity rotating packed bed liquid outlet 1403; the top is provided with a second high-gravity rotating packed bed liquid inlet 1402; the rotor is equipped with a second high-gravity rotating packed bed filler 1406, the bottom of the rotor is connected to the second motor 15, and is driven to rotate by the second motor 15; the second high-gravity rotating packed bed gas outlet 1401 is connected to the third foam column gas inlet 170 1, the second high gravity rotating packed bed liquid outlet 1403 is connected to the second liquid inlet 503 of the first high gravity rotating packed bed 5 through a one-way valve 16; the second high gravity rotating packed bed liquid inlet 1402 is connected to the diverter valve 21 below the defoamer 20, and the reflux liquid is transported to the interior of the second high gravity rotating packed bed packing 1406 through the second high gravity rotating packed bed liquid distributor 1405; a guide tube 1407 is set at the second high gravity rotating packed bed gas inlet 1404 to prevent excessive liquid from flowing into the second foam column and affecting the rise of bubbles.

[0051] Furthermore, the guide tube 1407 is an innovatively designed baffle, which includes an upper tube and a lower tube. Both the upper tube and the lower tube are hollow conical structures, and the outer side thereof is composed of a plurality of drainage baffles with arc-shaped raised structures connected in sequence to form a cylindrical structure. The upper tube and the lower tube are placed at an angle, and the two are combined into a structure that is narrow at both ends and wide in the middle, and the top opening of the upper tube is larger than the bottom opening of the lower tube. Specifically, each drainage baffle occupies 1 / 4 to 1 / 36 of the circumference of the guide tube. Under the action of centrifugal force, when the splashed liquid hits the upper tube, the raised part on the drainage baffle will drain the liquid into the groove between the two drainage baffles and flow along the direction of the groove, so that the originally concentrated fluid is dispersed to different groove directions by the impact force, changing the flow direction of the liquid. The lower tube is used to block the remaining liquid in the packing bed to prevent the liquid from entering the second foam column 13; under the action of the guide tube 1407, the liquid flows along the liquid outlet into the first supergravity rotating packing bed 5, which helps to stabilize the operation of the second foam column and prevent liquid impact; the overall height of the guide tube is set according to the size of the supergravity rotating packing bed and the foam column, the height ratio of the upper tube and the lower tube is between 1:2 and 1:10, the upper tube is inclined at an angle of 5° to 85° to the vertical direction, and the lower tube is inclined at an angle of 0° to 85° to the vertical direction.

[0052] Furthermore, the foam column includes a first foam column 12, a second foam column 13, and a third foam column 17; the foam column body is a closed cylindrical shape; a guide tube 1702 is provided on the side of the third foam column 17, and its outlet is connected to the defoamer 20. A reflux pipe is provided below the defoamer, and a diverter valve 21 is provided on the reflux pipe to control the flow rate. The defoaming liquid is introduced from the liquid inlet 1402 of the second supergravity rotating packed bed through a reflux pipe; the other reflux pipe is connected to the product tank 22; the first foam column gas inlet 1201 is connected to the gas delivery pipe, and the first foam column foam outlet 1203 is connected to the liquid outlet 505 of the first supergravity rotating packed bed; the second foam column 13 is connected to the gas outlet 504 of the first supergravity rotating packed bed 5 and the gas inlet 1404 of the second supergravity rotating packed bed above and below respectively; the third foam column gas inlet 1701 is connected to the gas outlet 1401 of the second supergravity rotating packed bed 14, and the third foam column foam outlet 1703 is connected to the defoamer 20.

[0053] Furthermore, the structure of the flow guide 1702 is as follows: it is located on the side of the third foam column 17, with an inclination angle ranging from 10° to 90°, and the outlet is connected to the defoamer 20; the structure of the defoamer 20 is as follows: the body of the device is cylindrical, and an ultrasonic device (i.e., an ultrasonic rod) is installed on one side of the interior, and the ultrasonic rod 201 extends into the interior to break the foam; a needle-shaped bubble breaker is set at the bottom and side, and the needle-shaped bubble breaker is a mace-shaped structure with sharp thorns set upward; the ultrasonic rod and the needle-shaped bubble breaker can be used simultaneously or separately, and the needle-shaped bubble breaker can be used separately. The size of the defoamer is determined by the size of the defoamer; a liquid level gauge 18 is placed on its top to monitor the foam generation rate and liquid level changes in real time, and adjust the feed flow or operating conditions through feedback control to avoid foam overflow caused by excessive liquid; a diverter valve 21 is set below the defoamer 20, and the diverter valve can be adjusted manually or automatically through a controller to accurately control the reflux rate of the defoaming liquid; a one-way valve 16 is set on the liquid outlet 1403 pipeline of the second supergravity rotating packed bed to control the one-way flow of the fluid and prevent liquid backflow.

[0054] Furthermore, the residual liquid tank 11 is connected to the liquid outlet 1202 on the side of the first foam column 12 .

[0055] Furthermore, the fillers 507 of the first high-gravity rotating packed bed and the fillers 1406 of the second high-gravity rotating packed bed are at least one or more combinations of ball ring fillers, wire mesh fillers, spherical fillers, arc saddle fillers, and honeycomb fillers, and the types of fillers can be replaced.

[0056] Furthermore, the height-to-diameter ratio of the foam column ranges from 5 to 50 and is designed based on the liquid flow rate and bubble diffusion characteristics to improve the gas-liquid contact efficiency and reduce the equipment pressure drop.

[0057] The present invention provides a high-gravity continuous foam separation method. In the above-mentioned high-gravity continuous foam separation device, the raw material liquid is foamed by the first high-gravity rotating packed bed 5 to generate a foam phase and a liquid phase. The foam phase passes through the gas outlet 504 of the first high-gravity rotating packed bed through the second foam column 13 and enters the second high-gravity rotating packed bed 14 for further foaming. Under the action of the gas, the foam continuously rises and enters the third foam column 17, and a high-concentration target substance is obtained in the defoamer 20; the liquid phase in the defoamer enters the second high-gravity rotating packed bed 14 due to the action of gravity to continue foaming, and the remaining liquid phase enters the first high-gravity rotating packed bed 5 to continue foam separation, and the remaining liquid phase component is obtained at the bottom of the first foam column.

[0058] The above-mentioned method of high-gravity continuous foam separation comprises the following steps:

[0059] Start the first motor 6 and the second motor 15 and set the rotation speeds of the first high-gravity rotating packed bed 5 and the second high-gravity rotating packed bed 14. The raw material liquid is driven by the pump 2 and injected into the first high-gravity rotating packed bed 5 after being measured by the liquid flow meter 4. At the same time, start the fan 7 to supply gas to the system. After the gas passes through the buffer tank 8, the gas velocity is stabilized by adjusting the gas flow meter 10. The gas pipeline is divided into two branches: one pipeline enters the first foam column 12 through the gas distributor 1204 and rises to the first high-gravity rotating packed bed 5; the other pipeline directly enters the first high-gravity rotating packed bed 5; the two branches The gas streams converge in the first high-gravity rotating packed bed 5; in the first high-gravity rotating packed bed, the liquid is thrown from the inside of the packing to the outside by the centrifugal force, and contacts with the gas to generate microbubbles; part of the liquid flows into the first foam column 12 through the liquid outlet 505 of the first high-gravity rotating packed bed 5, and the bubbles formed at this time continue to rise into the first high-gravity rotating packed bed 5 to achieve foam separation; the foam enters the second foam column 13 from the gas outlet 504 of the first high-gravity rotating packed bed, and continues to rise to the second high-gravity rotating packed bed 14 for continuous foaming, and at the same time undergoes foaming, recombination, During the processes of crushing and reorganization, the surface is constantly renewed, which effectively improves the material enrichment efficiency; during the rising process of the foam, part of the liquid it carries will flow through the second high-gravity rotating packed bed liquid outlet 1403 to the first high-gravity rotating packed bed 5 for re-circulation and separation; the foam in the second foam column 13 rises into the second high-gravity rotating packed bed 14, and continuously foams and rises into the third foam column 17 under the action of gas, and is finally collected in the defoamer 20 through the guide pipe 1702; in the defoamer 20, the bubbles are broken in the defoamer by the ultrasonic rod 201 or the needle-shaped bubble breaker A defoaming liquid is formed; the liquid level meter 18 at the top monitors the foam generation rate and liquid level changes in real time, and adjusts the feed flow or operating conditions through a feedback mechanism to prevent foam overflow; a diverter valve 21 is installed at the bottom of the defoamer 20, which can be adjusted manually or automatically to accurately control the reflux speed of the defoaming liquid; the diverter valve on the outlet pipe of the defoamer 20 is adjusted to control the diversion ratio of the reflux liquid and the defoaming liquid, so that a part of the defoaming liquid flows into the product tank 22, and the other part flows back to the second high-gravity rotating packed bed 14; after the entire separation process is completed, the product tank 22 collects the product, and the remaining residual liquid is collected by the residual liquid tank 11.

[0060] In the above method, the gas-liquid contact mode is one of cross-flow, counter-flow or co-flow, the hypergravity factor is 5 to 120; and the gas is at least one or more of air, carbon dioxide, nitrogen, oxygen or inert gas.

[0061] In the above separation methods, establishing a more optimal defoaming liquid reflux system and operating conditions requires comprehensive consideration of factors such as foam separation efficiency, operational stability, energy consumption, and product quality. The defoaming liquid reflux ratio ranges from 0 to 100%, allowing for full reflux or determining whether to reflux, as well as the reflux time, number of cycles, and reflux flow rate, based on product quality. This ensures that the defoaming liquid maintains sufficient foaming time in the rotating packed bed and matches the gas-liquid mixing efficiency.

[0062] (1) Full reflux (reflux ratio 100%) is suitable for scenarios where the concentration of the target substance in the wastewater is low (for example, protein concentration is less than 100 mg / L), and multiple cycles are needed to increase the enrichment ratio. The target substance is difficult to desorb from the gas-liquid interface, and a longer foam residence time is required. The gas-liquid ratio is generally 5:1 to 8:1, and the reflux flow rate is 100% of the feed flow rate.

[0063] (2) Partial reflux (reflux ratio 20%-80%) is applicable when the target substance concentration in the wastewater is moderate (e.g., protein concentration is 100-300 mg / L), product quality requirements are high, but a certain degree of wastewater discharge is allowed. The foam enrichment capacity is strong, but energy consumption and operational stability must be considered. The reflux ratio of 20%-80% can be optimized through gradual experiments, and it is recommended to start from 50% under common conditions.

[0064] (3) No reflux (reflux ratio 0%) is applicable when the target substance concentration in the wastewater is high (for example, protein concentration exceeds 300 mg / L) and the foam generation rate is high, so the recovery target can be achieved without multiple cycles. The gas-liquid ratio can be maintained at 3:1 to 5:1, without additional reflux.

[0065] Typically, the reflux time should be shorter than the equipment's processing cycle to ensure smooth, continuous operation. Install a level gauge to monitor the defoaming liquid's foam generation rate and level changes. Based on the foam generation rate, adjust the reflux time until the system reaches a stable state. The height of the foam column and packing material is determined based on the foam's rise rate, gas-liquid flow rate, and separation efficiency. Ultimately, select appropriate operating conditions to ensure continuous or semi-continuous operation of the process.

[0066] The separation efficiency of foam separation technology is evaluated by the enrichment ratio E and the recovery rate R:

[0067] Recovery rate:

[0068] Enrichment ratio:

[0069] Where, C f Indicates the concentration of target substance in the collected defoaming solution (mg / L), C 0 represents the initial concentration of the target solute in the feed solution (mg / L),C w Indicates the concentration of target substance in the residual liquid (mg / L); V w represents the residual liquid volume (L), V 0 represents the volume of the raw material solution (feed solution) (L), V f Indicates the volume of defoaming solution (L).

[0070] In order to make the above-mentioned purpose of the present invention more intuitive, the specific implementation methods of the technical solution of the present invention are described in detail below in conjunction with specific embodiments. Example 2

[0071] The experiment used a simulated surfactant wastewater, sodium dodecylbenzenesulfonate (SDBS) aqueous solution, as the system. The SDBS concentration was 300 mg / L. The experiment was a continuous operation, and the wastewater treatment volume each time was 8 L. The surfactant wastewater was pumped into the liquid inlet 502 of the first high-gravity rotating packed bed with a gas velocity of 600 L / h, a feed flow rate of 450 mL / min, a high-gravity factor of 40, a reflux ratio of 50%, and the experimental temperature was maintained at 25°C. The operation time was 30 min. The experiment was stopped when the foam no longer bulged, and the foam entered the product tank 22, and the remaining liquid entered the residual liquid tank 11 for collection.

[0072] Finally, it was concluded that the recovery rate of SDBS in this example was 95.98%, the enrichment ratio was 77, and the separation effect was good. Under the conditions of reflux ratios of 20%, 50%, and 80%, the corresponding reflux flow rates were set to 60 mL / min, 150 mL / min, and 240 mL / min, respectively. Example 3

[0073] The source of this experiment is soybean whey wastewater from a soy product production plant. Soy whey wastewater contains a large amount of organic matter, including COD (chemical oxygen demand) of 1500 mg / L and nitrogen content of 80 mg / L. Direct discharge will cause environmental pollution. Figure 1 ), effectively recovering proteins and other surfactants from wastewater while reducing the pollution load of the wastewater. The foam separation column has a height-to-diameter ratio of 6:1, and the packing height is 1 / 3 of the column height.

[0074] Experimental procedures: Soy whey wastewater was filtered through a 100-mesh filter to remove large suspended solids. Based on the effects of initial pH, bubble size, superficial gas velocity, feed concentration, and foam layer height on the foam separation of soy protein wastewater, SDS was added to the solution at a standardized mass ratio as a scavenger and foaming agent. 4 L of wastewater was then passed through a high-gravity continuous foam separation apparatus, and the gas pipeline system was activated and the gas velocity was adjusted. The apparatus was operated at atmospheric pressure for 30 minutes. Surfactants in the wastewater accumulated on the bubble surfaces, and the resulting foam was recovered by a top collector. The collected foam was then deposited in a defoamer to form a defoaming solution, which was then freeze-dried in a vacuum chamber to obtain a high-concentration protein product. The treated wastewater was discharged from the bottom outlet for subsequent analysis. Foam was collected every 60 seconds, weighed, and the volume of the foam solution was recorded.

[0075] Finally, the optimal separation conditions were determined: the experimental temperature was maintained at 25°C (controlled by a water bath), the whey protein concentration was 200 mg / L, the pH was 6.2, the first hypergravity factor was 45, the second hypergravity factor was 30, the gas velocity was 50 L / h, and the feed rate was 300 mL / min. The experiment was conducted for 25 minutes. The experiment was terminated when the foam ceased to bulge. The foam entered the product tank 22, and the residual liquid was collected in the residual liquid tank 11. The total recovery rate of soy whey protein in this example was 94.5%, and the enrichment ratio was 80, indicating good separation performance. The wastewater pollutant removal efficiency was 75% (reduced from 1500 mg / L to 375 mg / L), and the nitrogen content was reduced by 40% (from 80 mg / L to 48 mg / L). The foam enrichment ratio reached an optimal value of 80 at a reflux ratio of 50%. When the reflux ratio was below 20%, the foam stability decreased; when the reflux ratio was above 80%, the foam was excessively diluted.

[0076] By using this device to treat soybean whey wastewater, not only can high-value-added substances such as protein be efficiently recovered, but the concentration of pollutants in the wastewater can also be significantly reduced. This method is simple to operate and has low operating costs, providing an efficient solution for the resource utilization of soybean whey wastewater. Example 4

[0077] The soy whey wastewater from soy product production plants is treated using a super gravity continuous foam separation device consisting of multiple layers of fillers. The height-to-diameter ratio of the foam column is 6:1. The rotating filler bed is made of high-strength corrosion-resistant material. Its height is determined by the filler height and is divided into three layers (such as Figure 12As shown in the figure, the lower layer of packing is honeycomb packing 24, which promotes initial mixing of gas and liquid and increases the foam generation rate. The middle layer of packing is pall ring packing 25, which increases turbulence, enhances gas-liquid mass transfer, and improves separation efficiency. The upper layer of packing is wire mesh packing 26, which enhances microbubble stability, prolongs foam residence time, and significantly increases the enrichment ratio. Each packing layer accounts for one-third of the total packed bed height and is separated by stainless steel partitions. Each layer has a liquid inlet to ensure uniform liquid distribution. The wastewater primarily contains proteins and other surfactants, with an initial COD of 1500 mg / L and a protein concentration of 200 mg / L. During the experiment, the hypergravity factor was set to 50, the reflux ratio was adjustable, the feed flow rate was 300 mL / min, the gas flow rate was 50 L / h (air), and the temperature was 25°C (controlled by a water bath). The operation lasted 30 minutes, and the defoaming solution reflux ratio was 50%. The protein concentration of the foam solution was measured every 5 minutes, and the foam solution volume and wastewater treatment volume were recorded.

[0078] Experimental results showed that the foam column height remained stable at 20 cm, and the foam liquid concentration reached 800 mg / L, four times the initial protein concentration in the wastewater. The COD reduction rate was 72.33%, from 1500 mg / L to 415 mg / L. The total recovery rate was 90.5%. The enrichment ratio was 70, indicating that the device had excellent enrichment capacity. This multi-layered supergravity continuous foam separation device achieves efficient protein enrichment and effective wastewater purification through optimized packing structure and gas-liquid contact mechanism, making it suitable for application in soy product wastewater treatment and other bioseparation applications.

[0079] Anything not covered in the embodiments of the present invention can be selected by those skilled in the art from the prior art.

[0080] The above disclosure is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present invention, which should all be included in the protection scope of the present invention.

Claims

1. A high gravity continuous foam separation device, characterized by: It comprises n high-gravity rotating packed beds and n+1 foam columns, where n≥2; the foam columns and the high-gravity rotating packed beds are sequentially connected to form a separation device; When n=2, the separation device includes a first high-gravity rotating packed bed and a second high-gravity rotating packed bed, a first foam column, a second foam column, and a third foam column; The gas inlet of the first high-gravity rotating packed bed is connected to the gas inlet of the first foam column and the gas delivery pipeline at the same time, and the foam outlet of the first foam column is connected to the liquid outlet of the first high-gravity rotating packed bed; the gas inlet of the second foam column is connected to the gas outlet of the first high-gravity rotating packed bed, and the foam outlet of the second foam column is connected to the gas inlet of the second high-gravity rotating packed bed; the gas inlet of the third foam column is connected to the gas outlet of the second high-gravity rotating packed bed; the liquid inlet of the first high-gravity rotating packed bed is connected to the liquid outlet of the second high-gravity rotating packed bed and the liquid delivery pipeline at the same time; The gas delivery pipeline consists of a blower, a gas buffer tank, a gas valve and a gas flow meter connected in sequence; the liquid delivery pipeline consists of a raw material liquid tank, a pump, a liquid valve and a liquid flow meter connected in sequence; The core components of the first supergravity rotating packed bed and the second supergravity rotating packed bed are the same. The first supergravity rotating packed bed includes a rotor, packing, a shell, a motor, and a liquid distributor. The lower side of the shell is provided with a gas inlet, the top is provided with a liquid inlet and a gas outlet, and the bottom is provided with a liquid outlet; various packings are installed in the rotor, the bottom of the rotor is connected to the motor, and is driven to rotate by the motor; the liquid delivery pipeline sprays the liquid to the inner edge of the packing through the liquid distributor; the structure of the second supergravity rotating packed bed is the same as the above structure of the first supergravity rotating packed bed. In addition, the liquid inlet of the second supergravity rotating packed bed is connected to the diverter valve under the defoamer, and the reflux liquid is transported to the inside of the packing through the liquid distributor; a guide tube is provided at the gas inlet of the second supergravity rotating packed bed to prevent excessive liquid from flowing into the second foam column and affecting the rise of bubbles; the liquid outlet of the second supergravity rotating packed bed is provided with a one-way valve, and the liquid that has not been foam-separated continues to enter the first supergravity rotating packed bed; The guide tube includes an upper tube and a lower tube. Both the upper tube and the lower tube are hollow truncated cone structures. The outer side of the guide tube is connected in sequence by a plurality of drainage baffles with arc-shaped protrusions to form a cylindrical structure. The upper tube and the lower tube are placed at an angle. The two tubes are combined into a structure that is narrow at both ends and wide in the middle. The top opening of the upper tube is larger than the bottom opening of the lower tube. Under the action of centrifugal force, when the splashed liquid hits the upper cylinder, the raised part on the drainage partition will drain the liquid into the groove between the two drainage partitions and flow along the direction of the groove.

2. The high gravity continuous foam separation device according to claim 1, characterized in that: Each drainage baffle occupies 1 / 4 to 1 / 36 of the circumference of the guide tube, so that the originally concentrated fluid is dispersed to different groove directions by the impact force, changing the direction of liquid flow. The lower tube is used to block the remaining liquid in the packing bed to prevent the liquid from entering the second foam column; under the action of the guide tube, the liquid flows along the liquid outlet into the first high-gravity rotating packing bed, which helps to stabilize the operation of the second foam column and prevent liquid impact; the overall height of the guide tube is set according to the size of the high-gravity rotating packing bed and the foam column. The height ratio of the upper tube and the lower tube ranges from 1:2 to 1:

10. The upper tube is inclined at an angle of 5° to 85° to the vertical direction, and the lower tube is inclined at an angle of 0° to 85° to the vertical direction.

3. The high gravity continuous foam separation device according to claim 1, characterized in that: The foam column bodies of the first foam column, the second foam column and the third foam column are closed cylindrical; a guide pipe is provided on the side of the third foam column, and its outlet is connected to the defoamer. A reflux pipe is provided under the defoamer, and the defoaming liquid flows into the second supergravity rotating packed bed through the reflux pipe; another reflux pipe of the defoamer is connected to the product tank; whether to reflux, the reflux time, the number of cycles and the reflux flow rate are determined according to the product quality; the liquid outlet on the side of the first foam column is connected to the residual liquid tank.

4. The high gravity continuous foam separation device according to claim 3, characterized in that: The guide tube structure of the third foam column is an annular tube, which is arranged downwardly on the side of the third foam column with an inclination angle ranging from 10° to 90°, and the outlet end is connected to the defoamer; the defoamer structure is as follows: the body of the device is cylindrical, and an ultrasonic rod is installed on one side of the interior, which extends into the interior to break the foam; needle-shaped foam breakers are arranged at the bottom and side, and the needle-shaped foam breakers are mace-shaped structures with sharp spikes arranged upward; the ultrasonic rod and the needle-shaped foam breakers can be used simultaneously or separately, and the size of the needle-shaped foam breakers is determined according to the size of the defoamer; a liquid level gauge is provided at the top for real-time monitoring of the foam generation rate and liquid level changes. If the liquid level exceeds the set value, the feed flow rate or operating conditions need to be adjusted to avoid foam overflow caused by excessive liquid; a diverter valve is provided below the defoamer, which can be adjusted manually or automatically through a controller to accurately control the reflux rate of the defoaming liquid; the height-to-diameter ratio of the foam column ranges from 5 to 50.

5. The high gravity continuous foam separation device according to claim 1, characterized in that: The filler of the high-gravity rotating packed bed is at least one or more combinations of ball ring filler, wire mesh filler, spherical filler, arc saddle filler, and honeycomb filler, and the type of filler can be replaced.

6. The high gravity continuous foam separation device according to claim 5, characterized in that: The packing is composed of a multi-stage rotating packed bed connected in series or a combination of multiple packing layers; a combination of multiple packing layers refers to arranging packings of the same or different types or specifications in sequence to form multiple independent working layers, and the function and action point of each layer of packing are different; a multi-stage rotating packed bed connected in series refers to a multi-stage packing formed by connecting multiple independent rotating packed beds in series in sequence, and each rotating packed bed serves as an independent processing unit.

7. A high-gravity continuous foam separation method, using the high-gravity continuous foam separation device according to any one of claims 1 to 6, characterized in that: The raw material liquid is foamed in the first high-gravity rotating packed bed to generate a foam phase and a liquid phase. The foam phase passes through the gas outlet of the first high-gravity rotating packed bed through the second foam column and enters the second high-gravity rotating packed bed for further foaming. Under the action of the gas, the foam continues to rise and enters the third foam column, and a high-concentration target substance is obtained in the defoamer; the liquid phase in the defoamer returns to the second high-gravity rotating packed bed to continue foaming, and the remaining liquid phase flows into the first high-gravity rotating packed bed to continue foam separation, and the remaining liquid phase component is obtained at the bottom of the first foam column.

8. The high gravity continuous foam separation method according to claim 7, characterized in that The following steps are involved: (1) Start the motor and set the rotation speed of the first and second high-gravity rotating packed beds. The raw material liquid is driven by the pump and injected into the first high-gravity rotating packed bed after being measured by the rotor flowmeter. At the same time, start the fan to supply gas to the system. After the gas passes through the buffer tank, the gas velocity is stabilized by adjusting the flowmeter. The gas pipeline is divided into two branches: one pipeline enters the first foam column through the gas distributor and rises to the first high-gravity rotating packed bed; the other pipeline directly enters the first high-gravity rotating packed bed. (2) The two gases merge in the first high-gravity rotating packed bed; in the first high-gravity rotating packed bed, the liquid is thrown from the inside of the packing to the outside by the centrifugal force, and contacts with the gas to generate microbubbles; part of the liquid flows into the first foam column through the liquid outlet of the first high-gravity rotating packed bed, and the bubbles formed at this time continue to rise into the first high-gravity rotating packed bed to achieve foam separation; (3) The foam enters the second foam column from the gas outlet of the first high-gravity rotating packed bed, and continues to rise to the second high-gravity rotating packed bed for continuous foaming. At the same time, it undergoes the process of foaming, reorganization, crushing and reorganization. The surface is constantly renewed, which effectively improves the material enrichment efficiency. During the rising process of the foam, part of the liquid it carries will flow through the liquid outlet of the second high-gravity rotating packed bed to the first high-gravity rotating packed bed due to gravity for re-circulation and separation. (4) The foam in the second foam column rises into the second high-gravity rotating packed bed, continuously foams under the action of gas and rises into the third foam column, and is finally collected in the defoamer through the guide pipe; (5) In the defoamer, bubbles are broken by ultrasonic rods or needle-shaped bubble breakers to form defoaming liquid; the liquid level meter at the top monitors the foam generation rate and liquid level changes in real time; a diverter valve is installed at the bottom of the defoamer to control the diversion ratio of the reflux liquid and the defoaming liquid, so that part of the defoaming liquid flows into the product tank and the other part flows back to the second high-gravity rotating packed bed; After the entire separation process is completed, the product tank collects the product, and the remaining residual liquid is collected by the residual liquid tank; In the above method, the gas-liquid contact mode is one of cross-flow, counter-flow or co-flow, the hypergravity factor is 5 to 120; and the gas is at least one or more of air, carbon dioxide, nitrogen, oxygen or inert gas.

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