Double-membrane separation device and method for separating oil-water mixed phase

Abstract

A double-membrane separation device for separating an oil-water mixed phase comprises a membrane separation mother block, a cavity is formed in the membrane separation mother block, the left side and the right side of the membrane separation mother block are connected with a membrane separation mother block A and a membrane separation mother block B respectively, a hydrophilic oleophobic membrane is arranged between the membrane separation mother block and the membrane separation mother block A, and an oleophylic hydrophobic membrane is arranged between the membrane separation mother block and the membrane separation mother block B; a water phase discharge hole and an organic phase discharge hole are respectively formed in the separation ion block A and the membrane separation ion block B; the feeding hole is formed in the bottom of the membrane separation mother block. A double-membrane separation method for separating an oil-water mixed phase comprises the following steps: S1, injecting the oil-water mixed phase into an inner cavity of a membrane separation mother block through a feed port; S2, when the oil-water mixed phase is in contact with an oleophylic and hydrophobic membrane and a hydrophilic and oleophobic membrane, carrying out two-phase separation; and S3, after separation, the water phase flows out from a water phase discharge port, and the oil phase flows out from an organic phase discharge port 8.

Description

Technical Field

[0001] This patent relates to the field of nuclear chemical technology, and specifically to a double-membrane separation device and method for phase separation of oil-water mixed phases. Background Art

[0002] In the nuclear chemical production process, extraction is one of the main impurity purification technologies besides ion exchange, and plays an important role in nuclear fuel reprocessing and nuclear material chemical recovery. Compared with other separation processes, the extraction process has the following advantages: 1) It can meet the requirements of producing high-purity products and fine separation, and has a high recovery rate; 2) It is easy to realize continuous and automated production, which greatly reduces labor intensity and meets the requirements of modern industrial production. At the same time, the introduction of the extraction process can partially replace the cumbersome unit operations such as solid-liquid separation and medium conversion, which will help improve the efficiency of the production process; 3) The extraction process is carried out in a solution system, and compared with other production processes, the industrial waste produced is significantly reduced; 4) The extraction process is usually more economical.

[0003] At present, the extraction equipment in the nuclear chemical production process mainly includes mixing and settling tanks, pulse extraction columns and centrifugal extractors. Among them, the mixing and settling tank technology is the most mature, but there are problems such as large material and solvent retention, and there are certain limitations on the application environment; the advantage of the centrifugal extractor is that it has a small geometric size and a short material retention period, but its structure is complex, there are moving parts, and it is not easy to repair; the pulse extraction column is between the two. In comparison, it has the advantages of simple structure, good two-phase flow and mass transfer performance, easy to implement protective shielding, no internal moving parts, and convenient remote computer control, but for the nuclear material production process, there is still a problem of large online material volume.

[0004] Therefore, the present invention introduces a double-membrane separation device for phase separation of oil-water mixed phases. The device utilizes the difference in wettability of the oil and water phases with different types of membranes to separate the mixed phases. It can be used for continuous phase separation of mixed phases and has the advantages of small size, continuous phase separation process, and phase separation being independent of density difference. It can be applied to chemical production purification processes, and is particularly suitable for extraction and separation procedures in nuclear material production processes. Summary of the invention

[0005] The purpose of the present invention is to provide a double membrane separation device and method for oil-water mixed phase separation, which utilizes membrane separation technology to achieve continuous separation of mixed phases produced during extraction without mechanical movement of the device.

[0006] The technical solution of the present invention is: a double membrane separation device for phase separation of oil-water mixed phases, comprising a membrane separation mother block, the interior of the membrane separation mother block is a cavity, the left and right sides of the membrane separation mother block are respectively connected to a membrane separation sub-block A and a membrane separation sub-block B, and there is a hydrophilic and oleophobic membrane between the membrane separation mother block and the membrane separation sub-block A, and there is an oleophilic and hydrophobic membrane between the membrane separation mother block and the membrane separation sub-block B; the separation sub-block A and the membrane separation sub-block B are respectively equipped with a water phase discharge port and an organic phase discharge port; the feed port is located at the bottom of the membrane separation mother block.

[0007] The membrane separation mother block and the membrane separation sub-blocks A and B are sealed by O-rings.

[0008] The feed port and the membrane separation mother block are sealed by an O-ring B.

[0009] The pore size of the oleophilic and hydrophobic membranes is 0.11 microns.

[0010] The material of the oleophilic-hydrophobic membrane and the hydrophilic-oleophobic membrane is one of PTFE, PP and PVDF.

[0011] A double membrane separation method for oil-water mixed phase separation comprises the following steps:

[0012] S1: Inject the water-oil mixture into the internal cavity of the membrane separation mother block through the feed port:

[0013] S2: The water-oil mixture is in contact with the oleophilic-hydrophobic membrane and the hydrophilic-oleophobic membrane at the same time to separate the two phases;

[0014] S3: After separation, the water phase flows out from the water phase discharge port, and the oil phase flows out from the organic phase discharge port 8.

[0015] In S1, a pump is used to provide a driving force.

[0016] In S1, the maximum pressure inside the membrane separation mother block 4 is ≤4 bar.

[0017] The remarkable effect of the present invention is that the double membrane separation device for phase separation of oil-water mixed liquid described in the present invention is suitable for separation of mixed phases continuously generated in the extraction process and mixed phases generated in the scientific research test process. The present invention adopts membrane separation technology to separate the oil-water mixed phase generated by the extraction process. The overall design of the device has no moving components, and the separation process is carried out statically. Compared with the directional method of centrifugal extraction, the maintenance of moving components is avoided. A double-membrane separation design is adopted, and the difference in wettability is utilized. The two phases after mixing selectively pass through the side with the same wettability, which greatly ensures that the liquid after separation has no phase entrainment. The device described in the present invention can be designed and processed in a miniaturized manner. Compared with the phase separation components of the pulse extractor and the mixing and settling tank, it has the advantages of small device size and less online solution, and the advantage of continuous phase separation process. It is suitable for the separation of common low-viscosity extraction mixed liquid phases, and is also suitable for the extraction and separation of fissionable elements, avoiding critical risks. Compared with the traditional phase separation process, the device described in the present invention uses membranes with different wettability to separate the mixed phases, which changes the traditional method of using density difference for phase separation. It has a better separation effect for the situation where there is a transition between the light and heavy phases during the extraction process and the two phases with similar densities of the mixed phases. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view of a double membrane separation device for phase separation of oil-water mixture;

[0019] Figure 2 For schematic diagram

[0020] In the figure: 1-aqueous phase discharge port; 2-hydrophilic and oleophobic membrane; 3-membrane separation sub-block A; 4-membrane separation mother block; 5-O-ring A; 6-membrane separation sub-block B; 7-oleophilic and hydrophobic membrane; 8-organic phase discharge port; 9-O-ring B; 10-feed port. DETAILED DESCRIPTION

[0021] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific implementation disclosed below.

[0022] The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "a", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items.

[0023] It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0024] A double membrane separation device for oil-water mixed phase separation, mainly matching the separation of oil-water mixed phases produced in micro-mixing extraction and other continuous extraction processes.

[0025] It includes a membrane separation mother block 4, an oleophilic and hydrophobic membrane 7, and a hydrophilic and oleophobic membrane 2. The specific device design is as follows Figure 1 As shown. The interior of the membrane separation mother block 4 is a cavity, and the left and right sides of the membrane separation mother block 4 are connected to the membrane separation sub-block A3 and the membrane separation sub-block B6 respectively, and there is a hydrophilic and oleophobic membrane 2 between the membrane separation mother block 4 and the membrane separation sub-block A3, and there is an oleophilic and hydrophobic membrane 7 between the membrane separation mother block 4 and the membrane separation sub-block B6, and both are sealed by an O-ring 5: the separation sub-block A3 and the membrane separation sub-block B6 are respectively installed with a water phase discharge port 1 and an organic phase discharge port 8; the feed port 10 is located at the bottom of the membrane separation mother block 4 and is sealed by an O-ring B9.

[0026] A method for using a membrane separation device for phase separation of an oil-water mixture comprises the following steps:

[0027] S1: Use a pump to provide driving force to inject the water-oil mixture into the internal cavity of the membrane separation mother block 4 through the feed port 10:

[0028] S2: The water-oil mixture is in contact with the oleophilic-hydrophobic membrane 7 and the hydrophilic-oleophobic membrane 2 at the same time. By utilizing the difference in wettability, the organic phase in contact with the oleophilic-hydrophobic membrane 7 selectively permeates, and the water phase in contact with the hydrophilic-oleophobic membrane 2 selectively permeates, thereby achieving separation of the two phases.

[0029] S3: The two phases after separation flow out from their respective discharge ports.

[0030] In S1, the maximum pressure inside the entire device is ≤4 bar

[0031] In the above S2, the pore size of the oleophilic and hydrophobic membrane 7 and the hydrophilic and oleophobic membrane 2 is 0.11 micrometers, and the material is PTFE, PP, PVDF and other organic materials resistant to two-phase corrosion.

[0032] For the continuous mixed phase generated in the micro-mixed extraction process and other extraction processes, as well as the mixed phase waste liquid generated in the experimental process, the pump provides the driving force to pump the mixed phase from the feed port into the membrane separation device. At this time, the membrane separation device is placed vertically, and the two separation membranes are perpendicular to the ground. Under the pressure provided by the front end, a pressure difference is formed on both sides of the membrane, providing a driving force for the liquid to pass through the membrane. Under the action of pressure, according to the difference in wettability, the water phase selectively passes through the hydrophilic membrane, and the organic phase selectively passes through the oleophilic and hydrophobic membrane to achieve separation of the two phases. The separated two phases flow out of the membrane separation device along the corresponding discharge port to complete the separation of the two phases.

[0033] Embodiment 1:

[0034] A uranyl nitrate solution (extractant) with a concentration of 100.63 gU / L and an acidity of 2.3 mol / L was mixed with a 30% TBP solution (extractant) by using a T-type micromixer, wherein the flow rate of the uranyl nitrate solution was 4 mL / min, and the flow rate of the 65% TBP solution was 8 mL / min. After the extractant and the extractant were mixed by the T-type micromixer, they entered the membrane separator described in the present patent to separate the mixed phase, and a total of 1200 mL of the mixed phase was separated, and there was no obvious entrainment in the two phases after separation.

[0035] Embodiment 2:

[0036] A uranyl nitrate solution (extraction stock solution) with a concentration of 365.63 gU / L and an acidity of 2.5 mol / L was mixed with a 65% TBP solution (extraction agent) by using a T-type micromixer, wherein the flow rate of the uranyl nitrate solution was 5 mL / min, and the flow rate of the 65% TBP solution was 10 mL / min. After the extractant and the extraction stock solution were mixed by the T-type micromixer, they entered the membrane separator described in the present invention to separate the mixed phase, and a total of 300 mL of the mixed phase was separated. There was no obvious entrainment in the two phases after separation, and the two phases after separation were mixed, with the aqueous phase located in the upper layer and the organic phase located in the lower layer. Contrary to the fact that the density of the aqueous phase was greater than that of the organic phase before extraction, the separation of the device described in the present invention was not limited by the density difference.

[0037] Embodiment 3:

[0038] The organic phase was 30% TBP and the aqueous phase was 2.5 mol / L nitric acid solution. The membrane area on both sides was 20 cm 2 The flow rates of the two phases were set at 25 mL / min. The organic phase and the aqueous phase were mixed by a T-type micromixer and entered into a double membrane phase separator for phase separation. The phase separation results were observed. There was no obvious phase entrainment between the two phases after separation, and both phases were clear.

[0039] The above description is only a preferred embodiment of this patent and is not intended to limit this patent. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this patent should be included in the scope of protection of this patent.

[0040] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0041] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0042] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The optional embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can understand and use the present application well.

Claims

1. A double membrane separation device for oil-water mixed phase separation, characterized in that: The invention comprises a membrane separation mother block (4), the interior of the membrane separation mother block (4) is a cavity, the left and right sides of the membrane separation mother block (4) are respectively connected to a membrane separation sub-block A (3) and a membrane separation sub-block B (6), and a hydrophilic and oleophobic membrane (2) is provided between the membrane separation mother block (4) and the membrane separation sub-block A (3), and an oleophilic and hydrophobic membrane (7) is provided between the membrane separation mother block (4) and the membrane separation sub-block B (6); a water phase discharge port (1) and an organic phase discharge port (8) are respectively installed on the separation sub-block A (3) and the membrane separation sub-block B (6); and a feed port (10) is located at the bottom of the membrane separation mother block (4).

2. A double membrane separation device for oil-water mixed phase separation according to claim 1, characterized in that: The membrane separation mother block (4) is sealed with the membrane separation sub-block A (3) and the membrane separation sub-block B (6) via an O-shaped sealing ring (5).

3. A double membrane separation device for oil-water mixed phase separation according to claim 1, characterized in that: The feed port (10) and the membrane separation mother block (4) are sealed via an O-ring B (9).

4. A double membrane separation device for oil-water mixed phase separation according to claim 1, characterized in that: The pore sizes of the oleophilic and hydrophobic membrane (7) and the hydrophilic and oleophobic membrane (2) are 0.11 micrometers.

5. A double membrane separation device for oil-water mixed phase separation according to claim 4, characterized in that: The material of the oleophilic and hydrophobic membrane (7) and the hydrophilic and oleophobic membrane (2) is one of PTFE, PP and PVDF.

6. A double membrane separation method for oil-water mixed phase separation, using the double membrane separation device for oil-water mixed phase separation according to claim 1, characterized in that: The following steps are involved: S1: Inject the water-oil mixture into the inner cavity of the membrane separation mother block (4) through the feed port (10): S2: The water-oil mixture is in contact with the oleophilic-hydrophobic membrane (7) and the hydrophilic-oleophobic membrane (2) at the same time to separate the two phases; S3: After separation, the water phase flows out from the water phase outlet (1), and the oil phase flows out from the organic phase outlet (8).

7. A double membrane separation method for oil-water mixed phase separation according to claim 6, characterized in that: In S1, a pump is used to provide a driving force.

8. A double membrane separation method for oil-water mixed phase separation according to claim 7, characterized in that: In the above S1, the maximum pressure inside the membrane separation mother block (4) is ≤4 bar.

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