A new type of high-efficiency annular centrifugal extractor

Abstract

The present invention discloses a novel and efficient annular centrifugal extractor, which includes a rotating drum and a variable-diameter base. When the two-phase solutions are fed from the variable-diameter base and flow through the annular channel, they are driven to rotate by the blades on the outer wall of the rotating drum, realizing the relative movement and friction between the two-phase solutions and the inner wall of the variable-diameter base. The two-phase solutions undergo laminar flow and turbulent flow, achieving sufficient mixing and homogenization, and effectively realizing mass transfer between the liquid phases. The fixed blades on the variable-diameter base further enhance the mass transfer of the two-phase solutions by mixing. The baffle plates in the rotating drum block the upward flow rate of the two-phase liquids, further prolonging the mixing and mass transfer time of the two-phase solutions. For the extraction or stripping of substances or elements with slow reaction kinetics, the two-phase solutions can be effectively mixed and mass transferred in the centrifugal extractor of the present invention, improving the accuracy of extraction or stripping. Moreover, the centrifugal extractor of the present invention has a wide range of applications and can be effectively applied to the extraction or stripping of substances or elements with fast reaction kinetics.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid-liquid extraction equipment, and particularly relates to a novel and efficient annular-gap centrifugal extractor. Background Art

[0002] The annular-gap centrifugal extractor is a highly efficient liquid-liquid extraction equipment. It has the advantages of small liquid holdup, short residence time, strong phase separation performance, high extraction stage efficiency, convenient startup and shutdown, etc., and has been widely used in various fields such as pharmaceuticals, petrochemicals, hydrometallurgy, nuclear chemistry, and wastewater treatment.

[0003] In the prior art, the working process of the annular-gap centrifugal extractor includes two parts: mixing mass transfer and centrifugal phase separation; among which the mixing mass transfer is carried out in the annular gap; and the phase separation is carried out in the rotating drum. Specifically: when two-phase feed liquids with different densities and immiscible with each other enter the mixing zone of the centrifugal extractor from the feed ports respectively, the feed liquids are mixed in the annular-gap mixing zone under the drive of the rotating drum rotating at high speed. The mixed liquid enters the rotating drum from the bottom of the rotating drum and is phase-separated under the action of centrifugal force: the heavy phase reaches the inner wall of the rotating drum, flows through the channel to the heavy-phase collection chamber, and flows out from the heavy-phase outlet pipe; the light phase is in the central axis area of the rotating drum, flows through the channel to the light-phase collection chamber, and flows out from the light-phase outlet pipe.

[0004] The annular gap in the annular-gap centrifugal extractor is the mixing zone of the two-phase solution. To ensure that the mixing zone has a certain volume, the annular-gap area must have a certain volume. Therefore, the horizontal width of the annular gap cannot be too small, that is, there must be a certain distance between the drum and the inner wall of the base. On the one hand, in terms of the mixing degree of the two-phase solution: due to the certain width of the annular gap, when the two-phase solution is driven by the rotating drum rotating at high speed in the annular gap, the solution in the annular gap mainly undergoes laminar flow, and the laminar flow makes the mixing of the two-phase solution in the annular gap not sufficient. On the other hand, in terms of time, the solution in the annular gap will quickly enter the rotating drum under the action of gravity and the suction force of the drum to undergo phase separation, resulting in a short mixing time of the two-phase solution in the annular-gap area.

[0005] Therefore, the existing centrifugal extractors are suitable for the extraction or stripping of substances or elements with fast reaction kinetics. For substances or elements with slow reaction kinetics, the mass transfer rate of the substance or element between the liquid-liquid two-phase feed liquids is slow. When using the existing centrifugal extractors for extraction or stripping, the mixing degree of the two-phase feed liquids is poor, and the centrifugal extraction efficiency is low. Summary of the Invention

[0006] Aiming at the above technical problems existing in the prior art, the purpose of the present invention is to provide a novel and efficient annular-gap centrifugal extractor that is simultaneously suitable for the rapid mixing and centrifugal extraction of substances or elements with slow reaction kinetics.

[0007] To achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows: A novel and efficient annular-gap high-efficiency centrifugal extractor, comprising a rotating cylinder and a reduced-diameter base; the interior of the reduced-diameter base is a cavity with a gradually decreasing inner diameter from top to bottom; the rotating cylinder is located in the cavity of the reduced-diameter base, and a reduced-diameter annular-gap channel is formed between the rotating cylinder and the reduced-diameter base; a fixed blade is provided in the middle of the reduced-diameter base, below the rotating cylinder; a protruding blade plate is provided on the outer side wall of the middle and lower part of the rotating cylinder, and the blade plate is located in the annular-gap channel; a baffle plate is provided inside the rotating cylinder.

[0008] Further, the blade plate forms one or more vertical turning or arc turning channels in the annular-gap channel.

[0009] Further, inner blades are provided inside the rotating cylinder, and the baffle plate is located at the end of the inner blades.

[0010] Further, a mixed liquid inlet is provided at the bottom of the rotating cylinder, below the baffle plate.

[0011] Further, a light-phase feed inlet and a heavy-phase feed inlet are respectively provided on the middle side wall of the reduced-diameter base.

[0012] Further, a rotating-cylinder light-phase outlet is provided in the upper middle part of the side wall of the rotating cylinder, and a rotating-cylinder heavy-phase outlet is provided at its top.

[0013] Further, a base light-phase outlet and a base heavy-phase outlet are provided on the side wall of the reduced-diameter base.

[0014] Further, the base heavy-phase outlet, the base light-phase outlet, and the light-phase feed inlet are arranged on the reduced-diameter base from top to bottom.

[0015] Further, it further comprises a motor and a transmission component, the transmission component is connected to the rotating cylinder; the motor drives the transmission component to drive the rotating cylinder to rotate.

[0016] The beneficial effects brought by the technical solution adopted in the present invention are as follows. A novel and efficient annular-gap centrifugal extractor includes a rotating drum and a variable-diameter base. The interior of the variable-diameter base is a cavity with a decreasing inner diameter from top to bottom. The rotating drum is located in the cavity of the variable-diameter base, forming a variable-diameter annular-gap channel with the variable-diameter base. A fixed blade is provided in the middle of the variable-diameter base, below the rotating drum. Protruding blade plates are provided on the outer side wall of the middle and lower part of the rotating drum, and the blade plates are located in the annular-gap channel. A baffle plate is provided inside the rotating drum. When two-phase solutions enter from the variable-diameter base and flow through the annular-gap channel, they are rotated by the blade plates on the outer wall of the rotating drum, realizing the relative movement and friction between the two-phase solutions and the inner wall of the variable-diameter base, causing the two-phase solutions to flow in a laminar flow in the vertical direction of the channel; and in a turbulent flow in the horizontal direction. Due to the turbulent flow, the two-phase solutions are fully mixed and homogenized, and effective mass transfer between the liquid phases is achieved. When the two-phase solutions flow through the turning channel between the inside of the variable-diameter base and the protruding blade plates of the rotating drum, they not only flow in the vertical direction but also in the horizontal direction and finally reach the inside of the base. When the two-phase solutions flow through the channel in the horizontal direction, because the channel is relatively narrow, the flow rate of the two-phase solutions flowing through the horizontal channel is small, and the flow time is extended. At the same time, the homogenization time and mass transfer time of the two-phase solutions are increased, effectively adjusting the homogenization intensity and mass transfer time of the two-phase solutions, and coordinating the relative proportional relationship between the homogenization intensity and the mass transfer time. After being stirred by the fixed blade, the two-phase solutions are further mixed and mass transferred. After entering the inside of the rotating drum, the baffle plate can block the upward flow rate of the two-phase liquids, further extending the mixing time and mass transfer time of the two-phase solutions. For the extraction or stripping of substances or elements with slow reaction kinetics, the two-phase solutions can be effectively homogenized in the centrifugal extractor of the present invention, improving the accuracy of extraction or stripping. The centrifugal extractor of the present invention has a wide range of applications; for the extraction or stripping of substances or elements with fast reaction kinetics, the efficiency is further effectively improved; and the novel and efficient annular-gap high-efficiency centrifugal extractor of the present invention has a simple structure, is easy to manufacture and operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the novel and efficient annular-gap centrifugal extractor of an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of a traditional centrifugal extractor.

[0019] Where: heavy-phase outlet 1 of the rotating drum, rotating drum 2, heavy-phase outlet 3 of the base, light-phase outlet 4 of the rotating drum, light-phase outlet 5 of the base, light-phase inlet 6, heavy-phase inlet 7, inner blade 8, annular-gap channel 9, blade plate 10, baffle plate 11, variable-diameter base 12, mixed-liquid inlet 13, fixed blade 14, motor 15, transmission component 16. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0021] Embodiment 1

[0022] A novel and efficient annular-gap centrifugal extractor according to an embodiment of the present invention includes a rotating drum 2 and a variable-diameter base 12; the interior of the variable-diameter base 12 is a cavity with a decreasing inner diameter from top to bottom; the rotating drum 2 is located in the cavity of the variable-diameter base 12, and a variable-diameter annular-gap channel 9 is formed between the rotating drum 2 and the variable-diameter base 12; a fixed blade 14 is provided in the middle of the variable-diameter base 12, below the rotating drum 2; a protruding blade plate 10 is provided on the outer side wall of the middle and lower part of the rotating drum 2, and the blade plate 10 is located in the annular-gap channel 9; a baffle plate 11 is provided inside the rotating drum 2.

[0023] Preferably, the blade plate 10 forms a vertical turning channel in the annular-gap channel 9. The residence time of the two phases in the annular-gap channel 9 is extended, and the mass transfer time of the two-phase mixing is further extended.

[0024] Preferably, inner blades 8 are provided inside the rotating drum 2, and the baffle plate 11 is located at the end of the inner blades 8. The inner blades 8 divide the interior of the rotating drum 2 into 4 spaces, driving the two-phase liquid to rotate centrifugally.

[0025] Preferably, a mixed liquid inlet 13 is provided at the bottom of the rotating drum 2, directly below the baffle plate 11. The two-phase liquid in the variable-diameter base 12 enters the interior of the rotating drum through the mixed liquid inlet 13. The baffle plate 11 is directly above the mixed liquid inlet 13, blocking the mixed liquid from entering the rotating drum 2, reducing the rate of the two-phase liquid entering the interior of the rotating drum 2, and extending the mass transfer time of the two-phase liquid.

[0026] Preferably, a base heavy-phase outlet 3, a base light-phase outlet 5, a light-phase feed inlet 6, and a heavy-phase feed inlet 7 are respectively provided on the side wall of the variable-diameter base 12. The light-phase liquid enters the variable-diameter base 12 from the light-phase feed inlet 6, and the heavy-phase liquid enters the variable-diameter base 12 from the heavy-phase feed inlet 7. After the two-phase liquid enters the variable-diameter base 12, they are mixed in the annular-gap channel 9, and are rotated and mixed by the blade plate 10. The two phases are violently mixed and homogenized, and the substances or elements to be extracted or back-extracted are mass-transferred sufficiently between the two phases; the liquid after extraction or back-extraction flows out through the base heavy-phase outlet 3 and the base light-phase outlet 5 respectively.

[0027] Preferably, the light-phase feed inlet 6 and the heavy-phase feed inlet 7 are located on both sides of the variable-diameter base 12.

[0028] Preferably, a heavy-phase outlet 1 of the rotary drum 2 is provided at the top thereof, and a light-phase outlet 4 of the rotary drum is provided in the upper middle part of the side wall; the heavy-phase outlet 1 of the rotary drum is communicated with the heavy-phase outlet 3 of the base, and the light-phase outlet 4 of the rotary drum is communicated with the light-phase outlet 5 of the base. After the two-phase liquid enters the interior of the rotary drum 2, under the action of centrifugal force, the heavy phase is in the outermost layer inside the rotary drum 2, and the light phase is in the central axis part of the rotary drum 2; the heavy phase flows outwards along the heavy-phase outlet 1 on the rotary drum 2 and is thrown out in all directions, and finally flows out from the heavy-phase outlet 3 of the base; the light phase flows outwards along the light-phase outlet 4 on the rotary drum 2 and is thrown out in all directions, and finally flows out from the light-phase outlet 5 of the base.

[0029] Preferably, the heavy-phase outlet 3 of the base, the light-phase outlet 5 of the base, and the light-phase feed port 6 are arranged from top to bottom on the stepped base 12.

[0030] Preferably, it further includes a motor 15 and a transmission component 16, and the transmission component 16 is connected to the rotary drum 2; the motor 15 drives the transmission component 16 to drive the rotary drum 2. After the motor 15 is started, the speed is adjusted to the normal working speed of the centrifugal extractor; the rotary drum 2 is rotated together through the transmission component 16, and the two-phase feed liquid pump is started, and the two-phase feed liquid is respectively added into the interior of the stepped base 12 of the centrifugal extractor through the light-phase feed port 6 and the heavy-phase feed port 7.

[0031] Preferably, the inner diameter of the rotary drum 2 is 10 - 500 mm; the stepped base 12 and the rotary drum 2 are both symmetrical structures; the horizontal width of the vertical channel in the annular gap channel 9 is 1.5 - 2.5 mm, and the vertical height of the horizontal channel in the annular gap channel 9 is not affected by the inner diameter of the rotary drum 2 and can be controlled within 1 - 5 mm.

[0032] Embodiment 2

[0033] Refer to the appendix Figure 1 and 2 Using the centrifugal extractor of Embodiment 1 of the present invention and a traditional centrifugal extractor at an ambient temperature of 25 °C, back extraction is performed on Pu(IV) in 30% TBP-kerosene with an aqueous phase of 0.3 mol / L dimethylhydroxylamine, 0.2 mol / L methylhydrazine, and 0.40 mol / L HNO3; among them, the Pu(IV) concentration is 9.1 g / L, and the flow rate ratio of the organic phase to the aqueous phase is 4:1. The comparison results are shown in Table 1.

[0034] The diameters of the rotary drums 12 of both centrifugal extractors are 10 mm. The horizontal width of the vertical channel in the annular gap channel 9 of Embodiment 1 of the present invention is 2 mm, and the vertical height of the horizontal channel is 1 mm; the horizontal width of the vertical channel in the annular gap channel 9 of the traditional centrifugal extractor is 2 mm.

[0035] Table 1 Comparison of extraction results between the embodiment of the present invention and the traditional centrifugal extractor

[0036] Total flow rate (mL / min) Stage residence time (s) Stage efficiency Centrifugal extractor of Embodiment 1 of the present invention 4.2 10 68％ Traditional centrifugal extractor 4.2 22 84％

[0037] As can be seen from Table 1, the extraction efficiency of the centrifugal extractor in the first embodiment of the present invention is significantly improved compared with that of the traditional extractor.

[0038] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A new type of high-efficiency annular gap centrifugal extractor, characterized by: The invention comprises a rotating drum (2) and a variable diameter base (12); the interior of the variable diameter base (12) is a cavity with an inner diameter that decreases from top to bottom; the rotating drum (2) is located in the cavity of the variable diameter base (12), and an annular gap channel (9) with a turning and changing diameter is formed between the rotating drum (2) and the variable diameter base (12); a fixed blade (14) is provided in the middle of the variable diameter base (12), which is located below the rotating drum (2); a blade (10) is provided on the outer side wall of the middle and lower part of the rotating drum (2), and the blade (10) is located in the annular gap channel (9). The blade (10) forms a vertical turning or arc-shaped turning channel in the annular gap channel (9). When the two-phase solution flows through the turning channel between the interior of the variable diameter base and the protruding blade of the rotating drum, the blade (10) is turned vertically. , it not only flows in the vertical direction, but also flows in the horizontal direction, so that the mixing time and mass transfer time of the two-phase solution are increased. The horizontal width of the vertical channel in the annular gap channel (9) is 1.5 to 2.5 mm, and the vertical height of the horizontal channel in the annular gap channel (9) is 1 to 5 mm. A baffle (11) is provided inside the rotating drum (2), and the baffle (11) blocks the upward flow rate of the two-phase solution, further extending the mixing time and mass transfer time of the two-phase solution. An inner blade (8) is provided inside the rotating drum (2), and the baffle (11) is located at the end of the inner blade (8). A mixed liquid inlet (13) is provided at the bottom of the rotating drum (2), which is located directly below the baffle (11).

2. A novel high-efficiency annular gap centrifugal extractor according to claim 1, characterized in that: The side walls of the variable diameter base (12) are respectively provided with a base heavy phase outlet (3), a base light phase outlet (5), a light phase feed port (6), and a heavy phase feed port (7).

3. A novel high-efficiency annular gap centrifugal extractor according to claim 2, characterized in that: The light phase feed port (6) and the heavy phase feed port (7) are located on both sides of the variable diameter base (12); and the base heavy phase outlet (3) and the base light phase outlet (5) are provided on both sides of the variable diameter base (12).

4. A novel high-efficiency annular gap centrifugal extractor according to claim 2, characterized in that: The top of the rotating drum (2) is provided with a rotating drum heavy phase outlet (1), and the upper middle portion of the side wall is provided with a rotating drum light phase outlet (4); the rotating drum heavy phase outlet (1) is communicated with the heavy phase outlet (3) of the base, and the rotating drum light phase outlet (4) is communicated with the light phase outlet (5) of the base.

5. A novel high-efficiency annular gap centrifugal extractor according to claim 2, characterized in that: The base heavy phase outlet (3), the base light phase outlet (5), and the light phase feed port (6) are arranged from top to bottom on the variable diameter base (12).

6. A novel high-efficiency annular gap centrifugal extractor according to claim 1, characterized in that: It also includes a motor (15) and a transmission component (16), wherein the transmission component (16) is connected to the rotating drum (2); the motor (15) drives the transmission component (16) to drive the rotating drum (2) to rotate.

7. A novel high-efficiency annular gap centrifugal extractor according to claim 1, characterized in that: The inner diameter of the rotating drum (2) is 10 to 500 mm.

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