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CN-121754916-B - Vertical flow single kettle type extractor and adjusting method, multistage countercurrent extraction system connected in series and control adjusting method

CN121754916BCN 121754916 BCN121754916 BCN 121754916BCN-121754916-B

Abstract

The invention discloses a vertical flow single kettle type extractor and an adjusting method, a multistage countercurrent extraction system connected in series and a control adjusting method. The extractor is of a vertical single-kettle configuration, a mixing cylinder, a guide cylinder and a container outer shell are formed in the extractor, and the extractor further comprises a variable speed stirrer, phase clarification function fillers, a two-phase liquid inlet pipe orifice, a two-phase liquid outlet pipe orifice and the like. The variable speed stirrer drives the two-phase materials to be fully mixed in a downward plug flow mode in the mixing chamber to form stable pressurizing and conveying, and the mixed materials enter the annular clarifying chamber in a horizontal radiation flow after being turned back to realize efficient layering, and the discharging of the pressurizing pressure head is reserved. The countercurrent extraction system can support the extraction under pressure by connecting a plurality of stages of single kettle extractors in series according to a countercurrent mass transfer mode and configuring components such as interstage connection, regulation and control and the like. The system is operated according to a specific method, and can realize the full-line on-line and off-line continuous control of efficiency, on-line large-scale adjustment of treatment capacity, full-line adjustment of two-phase flow ratio, convenient startup and distribution, convenient shutdown and quality-division discharging and the like.

Inventors

  • LU JIANMING
  • JIANG YONG
  • XUE ZHILEI

Assignees

  • 南京圣卡孚科技有限公司

Dates

Publication Date
20260508
Application Date
20260302

Claims (20)

  1. 1. A vertical flow single kettle type extractor is used for liquid-liquid extraction operation between oil and water phases, and is characterized in that the extractor structurally comprises: an outer shell (3) of the vertical container is formed by assembling and welding a lower seal head, a cylinder body, an upper seal head and a top flange; The mixing cylinder (1) is coaxially arranged at the upper part of the outer shell (3); The guide cylinder (2) is a lower coaxial outer sleeve of the mixing cylinder (1), is arranged on a lower seal head of the outer shell (3), and guides fluid to the outer space between the mixing cylinder (1) and the guide cylinder (2); The components of the mixing drum (1) comprise a top sealing head (10) with a vertical drum section and a flange, a sealing ring (11), an inner drum section (12), a propulsion cavity (13) and a drainage taper pipe section (14), and a balance air interface is arranged on the top sealing head (10); the flange of the top sealing head (10) is matched with the top flange of the outer shell (3) and clamps the sealing ring (11) together, so that a pressure-isolating seal is formed for the inner space of the extraction machine, and the extraction machine can press the container standard for design and manufacture; after the top seal head (10), the mixing drum (1) and the guide drum (2) are assembled and connected with the outer shell (3), the inner space of the outer shell (3) is separated into a mixing chamber formed by the mixing drum (1) and the inside of the guide drum (2) and an annular clarifying chamber formed by the mixing drum (1) and the annular clarifying chamber formed by the guide drum (2) and the outer shell (3); The variable speed stirrer (4) is arranged at the top of the mixing drum (1), the transmission shaft of the variable speed stirrer is a multi-paddle stirring shaft (15) and extends into the mixing chamber, at least one mixing paddle (16) and at least one propelling paddle (17) positioned at the tail end of the multi-paddle stirring shaft (15) are arranged on the multi-paddle stirring shaft (15), the mixing paddle (16) is used for driving two-phase materials to be uniformly mixed, and the propelling paddle (17) is used for generating axial downward plug flow so as to convey blended materials; The light phase liquid inlet pipe orifice (5) and the heavy phase liquid inlet pipe orifice (6) are arranged on the same horizontal plane of the vertical cylinder section of the top sealing head (10); The light phase liquid outlet pipe orifice (7) and the heavy phase liquid outlet pipe orifice (8) are respectively arranged at the upper part and the lower part of the outer shell (3), are respectively provided with an inner drainage pipe, and are used for respectively leading out layered light phase and heavy phase from the top and the bottom of the clarification chamber, and the light phase drives gas phase discharge at the top of the clarification chamber to form the clarification chamber to be fully full of work; The phase interface sensor (9) is arranged on the upper end socket of the outer shell (3) and extends into the clarifying chamber, and is used for monitoring two-phase working interface levels in the clarifying chamber, wherein the upper part and the lower part of the interface levels are respectively light-phase and heavy-phase clarifying spaces, and a light-phase filler (18) and a heavy-phase filler (19) with clarifying functions are respectively arranged; the extractor is based on the combined action of the space combination of the mixing cylinder (1), the guide cylinder (2) and the outer shell (3) and the variable speed stirrer (4), a downward plug flow mixing-vertical flow clarifying flow field is formed in a single container space by two-phase medium, materials are driven to be mixed in the mixing chamber through the downward plug flow, and then are guided to turn back through the guide cylinder (2) so as to enter the clarifying chamber through horizontal radiation flow, layering is realized in the vertical direction, and both the light phase and the heavy phase after layering are pressurized and discharged.
  2. 2. The vertical flow single kettle extractor according to claim 1, characterized in that a circulation outlet (21) is provided near the height of the two-phase working interface of the outer casing (3), a circulation return port (22) is provided at the feed height of the mixing drum (1), and the connection between the two is formed by an internal circulation pipe valve assembly (23) consisting of a pipeline and a switch valve, so as to stop the two-phase feed in a single-stage working state, and simultaneously communicate the mixing chamber with the clarification chamber, thereby realizing the maintenance of the distribution and mass transfer balance of the two phases in the apparatus.
  3. 3. The vertical flow single kettle extractor according to claim 1, wherein the nominal diameter D and the height H of the outer shell (3) are determined according to the single machine residence time required by mass transfer separation, the diameter-height ratio D/H of the outer shell and the height-height ratio D/H is 0.7-1, the single machine residence time is determined within the range of 6-30 min according to the difference between the interfacial tension value and the density of two phases, the volume of the outer shell (3) is further determined, and the nominal diameter of D is calculated, and then H is determined by back calculation.
  4. 4. The vertical flow single kettle extractor according to claim 1, wherein, in the components of the mixing drum (1), the sealing ring (11) is connected with the inner drum section (12) by assembly welding, the inner drum section (12) is sequentially connected with the propulsion cavity (13) and the drainage taper pipe section (14) through the back taper reducing section, and the dimensions of the components comprise: The diameter d and the depth h of the propulsion cavity (13) are determined by the extraction working flow, the length-diameter ratio h/d is 0.45-1.5, specifically, the downward propulsion flow speed of the mixed liquid in the propulsion cavity (13) is selected within the range of 0.05-0.4 m/s from small to large according to the difference value between the interfacial tension value and the density of the two phases of extraction, and the rounding value of d is calculated; The diameter D1 of an inner barrel section of the mixing barrel (1) and the penetration length H2 of the propeller (17) are determined according to the mixing residence time of the two-phase medium in the mixing chamber within 1.5-7.5 min, and the conditions that the volume of the mixing chamber is calculated according to the mixing residence time, then the rounding value of D1 is selected within the range of 2.2d≤d1≤0.4-0.7D from small to large according to the difference between the interfacial tension value and the density of the extracted two-phase medium, and H2 is determined within the range of 0.24-0.72 times of the height H of the outer shell (3); the base angle alpha of the back taper reducing section is selected within the range of 20-50 degrees according to the fact that the difference between the interfacial tension value and the density of the two phases is large, and the penetration depth h1 of the upper edge surface of the propelling propeller (17) from the inlet of the propelling cavity (13) is 0.12-0.5 times of d; the cone angle beta of the drainage taper pipe section (14) is determined from small to large within the range of 5-55 degrees according to the length of the overflow pipe and the density difference of two phases.
  5. 5. The vertical flow single kettle extractor of claim 1, wherein the inner diameter d2 of the guide cylinder (2) is determined within the range of 0.4-1.1 times of the inner cylinder section diameter d1 of the mixing cylinder (1), and a plurality of clarifying chamber distributing openings (20) which are horizontally distributed are arranged at the top of the guide cylinder (2), wherein the line height H3 is designed according to the height of a two-phase interface in a working state and is the same as the median value of the detection depth of the phase interface sensor (9).
  6. 6. The vertical flow single kettle extractor according to claim 1, wherein the vertical distance H1 between the opening height of the light phase liquid inlet pipe orifice (5) and the heavy phase liquid inlet pipe orifice (6) and the flange sealing surface of the top sealing head (10) is 0.15-0.4 times of the diameter d1 of the inner barrel section of the mixing barrel (1).
  7. 7. The vertical flow single kettle extractor of claim 1, wherein the range of the phase interface sensor (9) corresponds to the range of effective adjustment of the height of the light-heavy two-phase interface in the working state, and the adjustment range is 0.1-0.3 times the height H of the outer shell (3).
  8. 8. The vertical flow single tank extractor according to claim 1, characterized by a light phase packing (18) and a heavy phase packing (19) installed in the light phase and heavy phase clarification spaces, the surface polarity of the two phase packing being the same as the polarity of the heterogeneous emulsion droplets in the respective spaces and the surface energy being similar.
  9. 9. The vertical flow single tank extractor according to claim 1 or 2, characterized in that a level sensor (24) for monitoring the working level in the mixing drum (1) is also provided on the top head (10).
  10. 10. The vertical flow single kettle extractor of claim 1 or 2, wherein the extractor distinguishes between a low pressure mode and a pressure mode according to the effect of the working pressure on the system mass transfer power, wherein the low pressure extraction mode is suitable for extraction occasions with working pressure not exceeding 0.3 MPa, the pressure extraction mode is suitable for extraction occasions with working pressure not lower than 0.3 MPa and not exceeding 3.2 MPa, and the pressure extraction mode is suitable for boosting the interphase mass transfer; In the low-pressure extraction mode, the rotating speed n of the variable speed stirrer (4) is 150-400 r/min, and the matching relation between the diameter d of the propulsion cavity (13) and the working flow Q of the extractor is as follows: When the diameter d of the propulsion cavity (13) is 70-190 mm, the working flow Q is 1.2-6 m3/h; When the diameter d of the propulsion cavity (13) is 190-250 mm, the working flow Q is 6-15 m < 3 >/h; when the diameter d of the propulsion cavity (13) is 250-325 mm, the working flow Q is 15-36 m3/h; when the diameter d of the propulsion cavity (13) is 340-400 mm, the working flow Q is 36-75 m3/h; when the diameter d of the propulsion cavity (13) is 400-475 mm, the working flow Q is 75-150 m3/h; When the diameter d of the propulsion cavity (13) is 475-550 mm, the working flow Q is 150-220 m <3 >/h.
  11. 11. The vertical-flow single-kettle extractor according to claim 10, wherein in the pressure extraction mode, the rotation speed n of the variable speed stirrer (4) is 150-600 r/min, and when n is 400-600 r/min, the push-down flow rate of the mixed liquid in the push-up cavity (13) is 1.5-3.5 times of the push-down flow rate in the low-pressure extraction mode.
  12. 12. The method for adjusting a vertical flow single kettle extractor according to claim 2, wherein the spreading and starting up are realized by the following steps: a) Opening a valve on the internal circulation pipe valve assembly (23) to communicate the mixing chamber and the clarification chamber; b) The light phase liquid outlet pipe orifice (7) and the heavy phase liquid outlet pipe orifice (8) are closed to prevent the light phase and the heavy phase from being discharged, the heavy phase is injected into the mixing chamber according to the preset proportion of the two phases, then the light phase is injected into the mixing chamber, and then the two-phase feeding is stopped; c) Starting a variable speed stirrer (4) and adjusting the speed to a preset rotating speed; d) And closing a valve on the internal circulation pipe valve assembly (23) to isolate the mixing chamber and the clarifying chamber, simultaneously starting continuous feeding of two phases according to a preset flow, and synchronously opening a light phase liquid outlet pipe orifice (7) and a heavy phase liquid outlet pipe orifice (8) to realize continuous feeding and discharging of the light phase and the heavy phase.
  13. 13. The method for adjusting a vertical flow single kettle extractor according to claim 2, wherein the method is characterized in that the method comprises the following steps: When the machine is temporarily stopped, the inner circulation pipe valve assembly (23) is started while the feeding and discharging of the two phases are stopped, so that the material circulation between the mixing chamber and the clarifying chamber is formed in the extractor, and the internal two-phase distribution and concentration balance are maintained; and when restarting, recovering two phases of feeding and discharging, and synchronously closing the internal circulation pipe valve assembly (23) to realize the impact-free restarting of the extractor.
  14. 14. The method for adjusting the vertical-flow single-kettle extractor according to claim 1, wherein the adjustment of the processing capacity is realized by actively increasing or decreasing the rotation speed of the variable speed stirrer (4) to continuously increase or decrease the downward plug flow generated by the propeller (17).
  15. 15. The method for adjusting the vertical flow single kettle extractor according to claim 1 or 2, wherein the deviation direction of the working liquid level signal of the mixing chamber, which is detected by the liquid level sensor (24), is used for reversely adjusting the rotating speed of the variable speed stirrer (4), changing the discharging flow of the propelling propeller (17), and the working liquid level signal of the liquid level sensor (24) returns to a set value and then returns the variable speed stirrer (4) to the set rotating speed, so that the adjustment for restraining the errors of the inlet flow and the outlet flow is realized.
  16. 16. The method for adjusting the vertical flow single kettle extractor according to claim 1, wherein after the flow rate of the raw material liquid or the concentration of the mass transfer component fluctuates, the control height of the phase interface sensor (9) is reset according to the two-phase balance required by the process reaching the standard, the outlet flow rates of the light phase outlet pipe orifice (7) and the heavy phase outlet pipe orifice (8) are slightly adjusted in opposite directions according to the increase and decrease of the two-phase volumes, so that the two-phase interface in the equipment is stabilized at the newly set target height, and the reverse adjustment of the two-phase balance is realized.
  17. 17. The method for adjusting the vertical flow single kettle extractor of claim 1, wherein the method for adjusting the two-phase flow ratio on line is realized by the following steps: a) Adjusting the liquid inlet flow of one phase or two phases to be changed, and synchronously changing the corresponding liquid outlet flow; b) Monitoring the consequent movement of the two-phase interface based on the signal of the phase interface sensor (9); c) When the interface moves to the height of the regulating target, the flow of the liquid outlet is continuously finely regulated, the monitoring signal of the phase interface sensor (9) is stabilized at the target height, D) The operating parameters are maintained at the current state, thereby locking the new two-phase flow ratio.
  18. 18. The multistage countercurrent extraction system is formed by connecting more than two stages of vertical flow single kettle type extractors according to claim 1 or 2 in series and is used for liquid-liquid countercurrent mass transfer, and is characterized in that the system selects the machine type with the same size or selects the machine type with 2-4 specifications according to the mass transfer grade according to the change amplitude of the two-phase volume in the extraction process for combination, and the multistage countercurrent extraction system further comprises the following system-level functional components: The whole line pressure balance main pipe is communicated to the top of each level of extraction machine and is provided with a switch valve, so that inert gas with preset pressure is filled into each level of extraction machine and the pressure balance of each level of single machine is realized; The device comprises an interstage connection and regulation pipeline assembly, a pressure meter (25) and a flow regulating valve (26) are arranged on each connecting pipeline, and the pressure meter is used for the contrast regulation of the flow of two phases or one phase between the stages; the whole line communication and interstage isolation assembly comprises a heavy phase discharge main pipe (27) communicated with the bottom of a clarification chamber of each level of extraction machine, a light phase overflow main pipe (28) communicated with the feeding height of a mixing chamber of each level of extraction machine, and a control valve arranged between each main pipe and the extraction machine, wherein the mixing chamber and the clarification chamber of each level of extraction machine are communicated with each other to form a multi-chamber communicating vessel, or are switched to the interstage isolation state that each level of extraction machine is formed into an independent concentration unit; The bypass reflux pipeline component is used for returning the raffinate phase to the raw material liquid inlet for whole-line bypass circulation when the system is started or is stopped in a planned way, and the extractor keeps countercurrent mass transfer until the concentration of the raffinate reaches the standard; through the arrangement of the system and the functional components and the coordination of the single machine control of each extractor, the system can perform specific whole-line control operation.
  19. 19. The method of claim 18, wherein the system is provided with the following specific functional operation modes by controlling and adjusting the functional components of the system and the extractors of each stage: the whole line standby and spreading actions are based on a whole line pressure balance main pipe and are adjusted by each level of single machine in cooperation, and the whole line pressure balance main pipe is used for carrying out the whole line standby according to preset pressure and spreading the two-phase materials rapidly; Each stage of isolation and internal circulation action is performed, and each stage of single machine adjustment is coordinated based on the whole line pressure balance main pipe and the whole line communication and interstage isolation assembly, the device is used for quickly establishing two-phase distribution in a system after the whole line standby and the spreading action and realizing the two-phase spreading of the whole line; the raffinate phase whole line bypass circulation action is based on a bypass return pipeline assembly and a whole line communication and interstage isolation assembly and is coordinated with each level of single machine adjustment, and is used for achieving the standard of the raffinate phase concentration in the system and preparing shutdown after each level of isolation and internal circulation action; the continuous countercurrent extraction action is based on the interstage connection and regulation pipeline components and is coordinated with the single machine regulation of each stage, so that the continuous countercurrent extraction action is used for normal operation after the whole-line bypass circulation action of the raffinate phase; The whole line temporary stopping action is used for temporarily interrupting the operation of production after the continuous countercurrent extraction action based on the internal circulation pipe valve assembly (23) and the whole line communication and interstage isolation assembly and is coordinated with the regulation of each stage of single machine; The whole line synchronous discharging action is based on an internal circulation pipe valve assembly (23) and an interstage connection and regulation pipeline assembly and is coordinated with the single machine adjustment of each stage, and is used for whole line stopping and flushing-free quality-dividing discharging after the whole line temporary stopping action.
  20. 20. The method for controlling and regulating a multistage countercurrent extraction system according to claim 18, wherein the system is controlled and regulated by the functional components of the system stage and the extractors of each stage to realize a specific on-line balance regulating function, and the method comprises three on-line regulation of adapting to short-term fluctuation regulation, two-phase flow ratio regulation and accumulated error elimination: the adaptive short-term fluctuation adjusting function is that when the feed flow of the raw material liquid or the concentration of the target component is changed in a short term, the control of the interstage connection and the adjusting pipeline assembly is based, the adaptive fluctuation adjustment of each level of single machine is cooperatively executed, the stability of the two-phase interface level inside each level of extraction machine is maintained under the reconstructed two-phase balance, and the fluctuation compensation adjustment of the whole system line is realized; the two-phase flow ratio adjusting function is that when the light-heavy two-phase flow ratio in the system needs to be changed, the two-phase flow ratio adjusting function is realized by adjusting and stabilizing the whole-line two-phase flow ratio based on the control of the interstage connection and regulation pipeline components and cooperatively executing the on-line two-phase flow ratio changing adjustment of each stage of single machine; The accumulated error eliminating function is that when the working liquid level of a certain stage or a plurality of stages of extractors needs to be recovered, the adjustment of the flow errors in and out is restrained based on each stage of single machines, and the control of the interstage connection and the regulation and control pipeline assembly is cooperatively executed, so that the accumulated error restraint of the whole line is realized.

Description

Vertical flow single kettle type extractor and adjusting method, multistage countercurrent extraction system connected in series and control adjusting method Technical Field The invention belongs to the technical field of liquid-liquid extraction separation, and particularly relates to a vertical flow single kettle type extractor and an adjusting method, a multistage countercurrent extraction system connected in series and a control adjusting method. Background The liquid-liquid extraction is an indispensable process link in the fields of chemical industry, hydrometallurgy, pharmacy, environmental protection and the like, and is widely implemented by adopting a box-type or groove-type mixer-clarifier device, wherein single-stage equipment consists of two chambers of mixing and clarifying, oil-water two-phase materials overflow into a clarifying chamber after being lifted upwards by a stirring paddle in the mixing chamber, and then two-phase layering is completed by gravity overflow along a longer path in the horizontal direction. In order to overcome the bias short circuit phenomenon accompanied by gravity overflow, damping members are often arranged for buffering and uniform distribution. The existing lifting-overflowing flow field causes remarkable functional restriction on extraction equipment, so that the equipment has the following inherent defects: First, the clarifier effect is weaker, thus the efficiency is lowered, and the extraction stage number is forced to be prolonged. The pressure head is lost after the upward lifting overflow of the mixing chamber, so that the clarifying chamber must rely on gravity overflow discharge, the height of the mixing chamber must be controlled to limit the power consumption corresponding to the lifting height, and the height of the clarifying chamber must be smaller than the height of the mixing chamber in order to ensure continuous and stable flow of two phases in the countercurrent extraction process. Therefore, the clarifying chamber can only adopt gravity overflow of a shallower layer, and secondary layering is easy to occur after two-phase discharging. Secondly, the two-phase flow ratio in countercurrent extraction is difficult to adjust. Liquid-liquid extraction can produce large mass transfer between two phases, and the volume of the two phases is obviously eliminated, so that the two-phase flow ratio needs to be adaptively adjusted, and the adjustment requirement is higher particularly when the feed concentration fluctuates. The light phase discharge under the lifting-overflow flow field has no pressure head, the mechanical signal of fluid cannot be automatically regulated, and any phase flow regulation inevitably causes the fluctuation of another phase, so that the fluctuation of the two-phase volume ratio in countercurrent extraction is easy to be subjected to multistage extension to form linkage oscillation, the stability of the light phase discharge after driving is not easy to be regulated, and the compared impact after restarting cannot be avoided particularly due to layering of materials in a mixing chamber during shutdown. Thirdly, the extraction efficiency, the operation power consumption and the online volume are difficult to be optimized in a comprehensive way, and most of the three are only in a rectangular tank structure, so that the defects of poor pressure resistance, poor sealing performance, difficult corrosion resistance and temperature control, large occupied area and the like of equipment are difficult to overcome, and the application expansion of the liquid-liquid extraction process is restricted. The above-mentioned drawbacks of the conventional mixer-settler restrict the efficacy in multi-stage, pressurized, solvent-volatile and flexible regulation scenarios. In order to overcome the above drawbacks, many technical efforts have been made in the industry to improve, but no fundamental improvement has been achieved. For example, CN 202006039U adopts the double-mixing chamber gradient stirring and is matched with the double-return pipe design, so that the extraction efficiency is improved, and a potential space for adjusting the single-machine treatment capacity is objectively obtained. CN 218774342U realizes equipment intensification through a concentric nested structure (inner cylinder mixing+outer cylinder clarifying), and improves sealing performance. CN 223263453U is used for strengthening the phase separation effect, reducing the volume of a clarification chamber, overflowing to a two-phase interface region of the clarification chamber for feeding after two-phase blending and lifting, strengthening the two-phase clarification effect by adding a space component, and CN 220071639U adopts an external heavy phase weir pipe and regulating barrel structure on the basis of a traditional CMS type mixer-clarifier, thereby improving the function of on-line regulating heavy phase flow. Although the above-mentioned technologies respectively imp