Annular space type centrifugal extractor

Abstract

The annular space type centrifugal extractor comprises a shell, a rotating cylinder is arranged in an inner cavity of the shell, the rotating cylinder is connected with a rotating shaft, and the rotating shaft penetrates through the top of the shell and is rotationally connected with the shell; an annular space is formed between the side wall of the rotary drum and the lower part of the shell and is communicated with a heavy phase inlet and a light phase inlet; a plurality of convex blocks are arranged in the annular space outside the side wall of the rotary drum, and are positioned below the heavy phase inlet and the light phase inlet; a porous medium structure is arranged in the annular space on the inner wall of the shell and located below the protruding block. According to the description of the scheme, the two-phase liquid mixing device has the beneficial effects that the structure is simple, the design is reasonable, the mixing strength of two-phase liquid in an annular space is enhanced, and the mass transfer time of the two-phase liquid is effectively prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of extraction, in particular to an annular gap type centrifugal extractor. Background Art

[0002] The annular gap centrifugal extractor is a highly efficient liquid-liquid extraction device. Its main body consists of a drum and a shell. It offers advantages such as low liquid retention, short residence time, compact size, integrated structure, strong phase separation performance, high extraction efficiency, easy start-up and shutdown, and a wide range of applications. It has been widely used in the pharmaceutical, petrochemical, hydrometallurgical, nuclear, and bioengineering industries.

[0003] In the prior art, the operating process of an annular gap centrifugal extractor primarily involves two steps: mixing and mass transfer within the annular gap, and centrifugal phase separation within the drum. Specifically, when two immiscible liquid phases (light phase and heavy phase) of different densities enter the annular gap region of the centrifugal extractor from their respective inlets, the high-speed rotation of the drum drives the incoming liquids through high-speed motion within the annular gap mixing zone, generating Taylor vortices and completing the mixing process. The mixed phase enters the drum through the drum inlet at the bottom of the drum, where it gradually separates into a light phase and a heavy phase under centrifugal force, completing the phase separation process. Simultaneously, the mixed phase moves upward under the action of pumping. The heavy phase flows through the heavy phase channel on the inner wall of the drum to the heavy phase collection chamber, and then out through the heavy phase outlet. The light phase flows through the light phase channel at the central axis of the drum to the light phase collection chamber, and then out through the light phase outlet pipe.

[0004] The annular gap region in an annular gap centrifugal extractor is the mixing zone for the light and heavy phases. This is the annular gap between the outer wall of the drum and the inner wall of the outer shell. To ensure sufficient mixing of the two phases, the annular gap region must have a certain volume, meaning the outer diameter of the drum must be smaller than the inner diameter of the outer shell. This annular gap presents two problems. First, the two phases of liquid in the annular gap are not fully mixed. Because mixing in the annular gap relies solely on the high-speed rotation of the drum, this can easily lead to insufficient mixing of the two phases, resulting in a light-phase enriched zone at the top and a heavy-phase enriched zone at the bottom. Second, due to the combined effects of gravity, pumping pressure, and the high-speed rotation of the drum, the two phases of liquid in the annular gap enter the drum too quickly and begin the phase separation process, resulting in a short mixing time for the two phases in the annular gap.

[0005] Existing centrifugal extractors have good effects on the extraction or stripping of substances or elements with fast reaction kinetics; for substances or elements with slow reaction kinetics, the two-phase liquid mixing degree is poor during extraction or stripping, and the mass transfer and extraction efficiency are low.

[0006] CN201510041215.2 describes an annular gap centrifugal extractor with vertical mixing baffles. Adding vertical baffles to the lower portion of the annular inner shell can improve mixing intensity to a certain extent, but the effect on increasing two-phase mass transfer time is modest, and there is no significant change in the extraction of elements with slow reaction kinetics. CN202211156604.6 describes a novel, high-efficiency annular gap centrifugal extractor with a variable diameter design at the bottom of the shell and blades added to the outer wall of the drum. This improves mixing efficiency and mass transfer time to a certain extent, but changes to the shell structure increase processing difficulty. Utility Model Content

[0007] The utility model aims to overcome the deficiencies in the prior art and provides an annular gap centrifugal extractor with a simple structure, reasonable design, enhanced mixing intensity of the two-phase liquid in the annular gap, and effectively increased mass transfer time of the two-phase liquid.

[0008] In order to achieve the above-mentioned purpose, the utility model provides an annular gap centrifugal extractor, comprising a shell, a rotor provided in the inner cavity of the shell, the rotor connected to a rotating shaft, the rotating shaft passing through the top of the shell and rotatably connected to the shell; a rotor inlet provided at the bottom of the rotor, the rotor inlet communicates with the inner cavity of the rotor, the inner cavity is communicated with a light phase outlet and a heavy phase overflow port; a light phase weir is provided on the upper part of the side wall of the rotor, the heavy phase overflow port is provided at a position of the light phase weir close to the side wall of the rotor, the inner cavity is communicated with the light phase outlet at the top of the light phase weir; the heavy phase overflow port is communicated with the heavy phase outlet; a heavy phase weir is provided on the upper part of the rotor, the heavy phase overflow port and the heavy phase outlet are connected at the upper part of the rotor The top of the heavy phase weir is connected; a light phase collecting chamber and a heavy phase collecting chamber are provided on the upper part of the shell, and the heavy phase collecting chamber is located above the light phase collecting chamber; the heavy phase rejection outlet corresponds to the heavy phase collecting chamber, and the heavy phase collecting chamber is connected to the heavy phase outlet; the light phase rejection outlet corresponds to the light phase collecting chamber, and the light phase collecting chamber is connected to the light phase outlet; an annular gap is provided between the side wall of the rotating drum and the lower part of the shell, and the annular gap is connected to the heavy phase inlet and the light phase inlet; a number of raised blocks are provided on the outside of the side wall of the rotating drum in the annular gap, and the raised blocks are located below the heavy phase inlet and the light phase inlet; a porous medium structure is provided on the inner wall of the shell in the annular gap, and the porous medium structure is located below the raised blocks.

[0009] Furthermore, the diameter of the circular hole formed by the heavy phase weir and the light phase weir is larger than the diameter of the drum inlet.

[0010] Furthermore, the porous medium structure is a ring structure.

[0011] Furthermore, the raised blocks are distributed in a plurality of vertical rows, and the raised blocks are evenly distributed in two upper and lower circles.

[0012] Furthermore, a hydrophilic / hydrophobic coating is sprayed on the surface of the protruding block.

[0013] Furthermore, a baffle is provided in the inner cavity near the inlet of the drum.

[0014] Furthermore, the number of the protruding blocks is 8-16.

[0015] Furthermore, the radial dimension of the porous medium structure is 1-10 mm, the vertical height is 3-400 mm, and the radial dimension of the annular gap is 0.5-2 mm larger than the radial dimension of the porous medium structure.

[0016] Furthermore, the radial dimension of the protruding block is 1-10 mm, the vertical height is 1-100 mm, the circumferential dimension is 1-5 mm, and the radial dimension of the annular gap is 0.5-2 mm larger than the radial dimension of the protruding block.

[0017] During operation, the light phase liquid enters the annular gap from the light phase inlet, and the heavy phase liquid enters the annular gap from the heavy phase inlet. The light phase liquid and the heavy phase liquid meet in the annular gap and are mixed under the influence of the drum side wall and the protruding blocks.

[0018] A mixture of light-phase and heavy-phase liquids enters the inner chamber of the drum through the drum inlet at the bottom. As the drum rotates, the liquid in the inner chamber is pulled toward the inner wall by centrifugal force. Because the diameter of the circular holes formed by the heavy-phase weir and the light-phase weir is larger than the diameter of the drum inlet, the liquid climbs up the drum under the centrifugal force, passing over the heavy-phase weir and the light-phase weir, and is ejected through the heavy-phase and light-phase ejection outlets.

[0019] Due to the obstruction of the porous medium structure, the liquid flow rate in the annular gap slows down and the mixing time becomes longer. After the mixed liquid enters the inner cavity of the drum, due to the rotation of the drum, the centrifugal force separates the heavy phase liquid and the light phase liquid. When the heavy phase liquid moves closer to the side wall of the drum, it drives the light phase liquid toward the axis of the drum.

[0020] Therefore, the accumulated light phase liquid passes over the light phase weir, is thrown into the light phase collection chamber from the light phase outlet, and then flows out from the light phase outlet for collection.

[0021] At the same time, the heavy phase near the side wall of the drum will climb up along the heavy phase overflow until it crosses the heavy phase weir and enters the heavy phase outlet, and then is thrown into the heavy phase collection chamber, and then flows out from the heavy phase outlet for collection.

[0022] The beneficial effects of this solution can be seen from the description of the above solution. It has a simple structure and reasonable design and has the following advantages:

[0023] (1) The raised blocks are set in the annular gap to play a certain stirring role, accelerating the turbulent flow of the two-phase liquid in the annular gap, and promoting the full mixing and uniform mixing of the two-phase liquid in the annular gap;

[0024] (2) Spraying a hydrophilic / hydrophobic coating on the protrusions facilitates the full mixing and uniform mixing of the two-phase liquids, further enhancing the mixing intensity of the two-phase liquids in the annular gap;

[0025] (3) The two-phase liquid in the annular gap must flow through the porous medium structure before entering the inner cavity of the drum. The flow time in the porous medium structure is prolonged, and the mixing time of the two-phase liquid is increased. For the extraction of elements with slow reaction kinetics, the mass transfer time is effectively increased, and the applicability of the centrifugal extractor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the utility model;

[0027] Figure 2 for Figure 1 A-A sectional view;

[0028] Figure 3 for Figure 1 B-B sectional view;

[0029] Figure 4 for Figure 1 C-C sectional view;

[0030] In the figure, 1. outer shell; 2. rotating drum; 3. rotating drum inlet; 4. light phase outlet; 5. heavy phase overflow outlet; 6. light phase weir; 7. heavy phase outlet; 8. heavy phase weir; 9. light phase collecting chamber; 10. heavy phase collecting chamber; 11. heavy phase outlet; 12. light phase outlet; 13. annular gap; 14. heavy phase inlet; 15. light phase inlet; 16. raised block; 17. porous medium structure; 18. baffle. DETAILED DESCRIPTION

[0031] In order to clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods. Example 1

[0032] like Figure 1-4 As shown ( Figure 2 and Figure 3It mainly represents the annular shape of the heavy phase weir, light phase weir, heavy phase collection chamber, and light phase collection chamber. To avoid too many lines in the figure, other information is omitted). This embodiment is an annular gap 13-type centrifugal extractor, including a shell 1. The inner cavity of the shell 1 is provided with a rotor 2, and the rotor 2 is connected to a rotating shaft. The rotating shaft passes through the top of the shell 1 and is rotatably connected to the shell 1; a rotor inlet 3 is provided at the bottom of the rotor 2, and the rotor inlet 3 is connected to the inner cavity of the rotor 2, and the inner cavity is connected to a light phase outlet 4 and a heavy phase overflow port 5; a light phase weir 6 is provided on the upper part of the side wall of the rotor 2, and the heavy phase overflow port 5 is provided at the position of the light phase weir 6 close to the side wall of the rotor 2, and the inner cavity is connected to the light phase outlet 4 at the top of the light phase weir 6; the heavy phase overflow port 5 is connected to the heavy phase outlet 7; a heavy phase weir 8 is provided on the upper part of the rotor 2, and the heavy phase overflow port 5 It is connected to the heavy phase rejection outlet 7 at the top of the heavy phase weir 8; a light phase collecting chamber 9 and a heavy phase collecting chamber 10 are provided on the upper part of the shell 1, and the heavy phase collecting chamber 10 is located above the light phase collecting chamber 9; the heavy phase rejection outlet 7 corresponds to the heavy phase collecting chamber 10, and the heavy phase collecting chamber 10 is connected to the heavy phase outlet 11; the light phase rejection outlet 4 corresponds to the light phase collecting chamber 9, and the light phase collecting chamber 9 is connected to the light phase outlet 12; an annular gap 13 is provided between the side wall of the rotating drum 2 and the lower part of the shell 1, and the annular gap 13 is connected to the heavy phase inlet 14 and the light phase inlet 15; eight protrusions 16 are provided on the outside of the side wall of the rotating drum 2 in the annular gap 13, and the protrusions 16 are located below the heavy phase inlet 14 and the light phase inlet 15; a porous medium structure 17 is provided on the inner wall of the shell 1 in the annular gap 13, and the porous medium structure 17 is located below the protrusions 16.

[0033] The diameter of the circular hole formed by the heavy phase weir 8 and the light phase weir 6 is larger than the diameter of the drum inlet 3 .

[0034] The porous medium structure 17 is an annular structure.

[0035] The raised blocks 16 are distributed in four vertical rows, and the raised blocks 16 are evenly distributed in two upper and lower circles.

[0036] The surface of the protruding block 16 is sprayed with a hydrophilic / hydrophobic coating.

[0037] A baffle 18 is provided in the inner cavity near the drum inlet 3 .

[0038] The diameter of the drum 2 is 10 mm, and the radial dimension of the annular gap 13 is 2 mm. The radial dimension of the raised block 16 is 1 mm, the vertical height is 1 mm, and the circumferential dimension is 1 mm. The distance between the upper and lower raised blocks 16 is 1 mm. The porous medium structure 17 has a radial dimension of 1.5 mm and a vertical height of 3 mm.

[0039] During operation, the light phase liquid enters the annular gap 13 from the light phase inlet 15, and the heavy phase liquid enters the annular gap 13 from the heavy phase inlet 14. The light phase liquid and the heavy phase liquid meet in the annular gap 13 and are mixed under the influence of the side wall of the drum 2 and the protrusions.

[0040] The mixture of light-phase liquid and heavy-phase liquid enters the inner cavity of the drum 2 through the drum inlet 3 at the bottom of the drum 2. Due to the rotation of the drum 2, the liquid in the inner cavity of the drum 2 will move toward the inner wall of the drum 2 under the action of centrifugal force. At this time, because the diameter of the circular hole formed by the heavy-phase weir 8 and the light-phase weir 6 is larger than the diameter of the drum inlet 3, under the action of centrifugal force, the liquid will climb up the drum 2, pass over the heavy-phase weir 8 and the light-phase weir 6, and be thrown out through the heavy-phase throw-out outlet 7 and the light-phase throw-out outlet 4.

[0041] Due to the obstruction of the porous medium structure 17, the liquid flow rate in the annular gap 13 slows down and the mixing time becomes longer. After the mixed liquid enters the inner cavity of the drum 2, due to the rotation of the drum 2, the centrifugal force separates the heavy phase liquid and the light phase liquid. When the heavy phase liquid moves closer to the side wall of the drum 2, it drives the light phase liquid toward the axis of the drum 2.

[0042] Thus, the accumulated light phase liquid passes over the light phase weir 6, is thrown into the light phase collecting chamber 9 through the light phase throwing outlet 4, and then flows out through the light phase outlet 12 for collection.

[0043] At the same time, the heavy phase near the side wall of the drum 2 will climb up along the heavy phase overflow port 5 until it passes over the heavy phase weir 8 and enters the heavy phase outlet 7, and then is thrown into the heavy phase collection chamber 10, and then flows out from the heavy phase outlet 11 for collection.

[0044] A mass transfer experiment was carried out using a 30% TRPO / kerosene-Fe-containing HNO3 solution system, wherein the Fe concentration was 14.2 g / L, the HNO3 concentration was 1.0 mol / L, the organic phase and aqueous phase flow rates were both 100 ml / h, and the rotation speed was 4500 r / min. The mass transfer stage efficiency of Fe in the traditional annular gap 13-type centrifugal extractor was 8.55%, while the mass transfer stage efficiency of the utility model was 12.88%, which was significantly improved. Example 2

[0045] Unlike Example 1, this embodiment has a drum 2 diameter of 60 mm, an annular gap 13 with a radial dimension of 4 mm. The raised block 16 has a radial dimension of 3 mm, a vertical height of 3 mm, and a circumferential dimension of 2 mm. The distance between the upper and lower raised blocks 16 is 2 mm. The porous medium structure 17 has a radial dimension of 3 mm and a vertical height of 8 mm.

[0046] A mass transfer experiment was carried out using a 30% TRPO / kerosene-Nd-containing HNO3 solution system, wherein the Nd concentration was 0.54 g / L, the HNO3 concentration was 1.0 mol / L, the organic phase and aqueous phase flow rates were both 40 L / h, and the rotation speed was 2200 r / min. The mass transfer stage efficiency of Nd in the traditional annular gap centrifugal extractor was 95.08%, while the mass transfer stage efficiency of the utility model was 99.88%, which was significantly improved.

[0047] The technical features not described in the present invention can be realized through or by adopting the existing technology, and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. An annular gap centrifugal extractor, characterized in that: The invention comprises an outer shell, wherein the inner cavity of the outer shell is provided with a rotating drum, the rotating drum is connected to a rotating shaft, the rotating shaft passes through the top of the outer shell and is rotatably connected to the outer shell; the bottom of the rotating drum is provided with a rotating drum inlet, the rotating drum inlet is connected to the inner cavity of the rotating drum, and the inner cavity is connected to a light phase outlet and a heavy phase overflow port; a light phase weir is provided on the upper part of the side wall of the rotating drum, the heavy phase overflow port is provided at a position of the light phase weir close to the side wall of the rotating drum, the inner cavity is connected to the light phase outlet at the top of the light phase weir; the heavy phase overflow port is connected to the heavy phase outlet; a heavy phase weir is provided on the upper part of the rotating drum, the heavy phase overflow port is connected to the heavy phase outlet at the top of the heavy phase weir; the upper part of the outer shell A light phase collection chamber and a heavy phase collection chamber are provided, and the heavy phase collection chamber is located above the light phase collection chamber; the heavy phase rejection outlet corresponds to the heavy phase collection chamber, and the heavy phase collection chamber is connected to the heavy phase outlet; the light phase rejection outlet corresponds to the light phase collection chamber, and the light phase collection chamber is connected to the light phase outlet; an annular gap is provided between the side wall of the rotating drum and the lower part of the shell, and the annular gap is connected to the heavy phase inlet and the light phase inlet; a plurality of raised blocks are provided on the outside of the side wall of the rotating drum in the annular gap, and the raised blocks are located below the heavy phase inlet and the light phase inlet; a porous medium structure is provided on the inner wall of the shell in the annular gap, and the porous medium structure is located below the raised blocks.

2. The annular gap centrifugal extractor according to claim 1, characterized in that: The diameter of the circular hole formed by the heavy phase weir and the light phase weir is larger than the diameter of the drum inlet.

3. The annular gap centrifugal extractor according to claim 1, characterized in that: The porous medium structure is a ring structure.

4. The annular gap centrifugal extractor according to claim 1, characterized in that: The raised blocks are distributed in a plurality of vertical rows, and the raised blocks are evenly distributed in two upper and lower circles.

5. The annular gap centrifugal extractor according to claim 1, characterized in that: The surface of the protruding block is sprayed with a hydrophilic or hydrophobic coating.

6. The annular gap centrifugal extractor according to claim 1, characterized in that: A baffle is provided in the inner cavity near the inlet of the drum.

7. The annular gap centrifugal extractor according to claim 1, characterized in that: The number of the raised blocks is 8-16.

8. The annular gap centrifugal extractor according to claim 1, characterized in that: The radial dimension of the porous medium structure is 1-10 mm, the vertical height is 3-400 mm, and the radial dimension of the annular gap is 0.5-2 mm larger than the radial dimension of the porous medium structure.

9. The annular gap centrifugal extractor according to claim 1, characterized in that: The radial dimension of the protruding block is 1-10 mm, the vertical height is 1-100 mm, the circumferential dimension is 1-5 mm, and the radial dimension of the annular gap is 0.5-2 mm larger than the radial dimension of the protruding block.

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