A continuous liquid-liquid separation device

Abstract

The utility model belongs to the liquid-liquid separation technical field in fine chemical industry, specifically discloses a kind of continuous liquid-liquid separation device, including mixed phase import, three-stage flow guide phase separation structure, DCS control system, light component liquid outlet and heavy component liquid outlet;Three-stage flow guide phase separation structure includes mixed phase area, main phase separation area, heavy component liquid refining area and several baffle.The separation device of the utility model utilizes the density difference of light component and heavy component, and gravity stratification is driven to realize natural stratification in static flow field;Different height baffle is used to form three-stage flow guide structure, to guide fluid to form stable laminar flow, and multi-stage flow guide is strengthened, so that stratification time is shortened to 5 minutes.Through different nominal diameter DN50 / DN25 pipeline configuration, dynamic balance of two-phase interface is realized, light component is discharged preferentially, heavy component is avoided to be entrained, liquid-liquid efficient separation is realized, and continuous and stable discharge is realized.

Description

Technical Field

[0001] This utility model belongs to the field of liquid-liquid separation technology in fine chemical industry, and specifically discloses a continuous liquid-liquid separation device. Background Technology

[0002] In chemical production, liquid separation equipment is widely used to recover and reuse useful liquids. Liquid-liquid separation equipment is used to separate two immiscible liquids with different specific gravities, effectively separating at least two liquids into layers. It can be applied to extraction, washing, and water separation processes in pharmaceuticals, pesticides, and petrochemicals. Existing liquid-liquid separation technologies mainly include:

[0003] (1) Separation using gravity settling equipment, mainly represented by traditional stratification tanks and batch separation vessels. The working principle is to use the density difference between the aqueous phase and the organic phase to achieve separation through static stratification. It is mainly suitable for systems with large density differences and low emulsification, such as dehydration of crude oil products.

[0004] (2) Separation is achieved using centrifugal separation equipment, primarily represented by centrifugal extractors (such as the CWL-M series) and disc centrifuges. The working principle involves generating a centrifugal force field through high-speed rotation (separation factor reaching 300-1000g), thereby enhancing the separation speed of the two phases. This method is mainly suitable for high-viscosity, high-density-difference, or easily emulsified systems, such as antibiotic extraction in the pharmaceutical industry.

[0005] (3) Separation is achieved using membrane separation technology, with the main equipment being ceramic membrane and polymer membrane separation devices. The working principle is to utilize the selective permeation characteristics of the membrane to achieve phase separation. It is mainly suitable for systems requiring the separation of trace components or high precision, such as boron extraction from salt lakes.

[0006] (4) Separation is achieved using extraction tower equipment, such as packed towers and pulse sieve plate towers. The working principle is to achieve mass transfer and separation through multi-stage countercurrent contact. It is mainly suitable for large-scale continuous production, such as aromatic hydrocarbon extraction in petrochemicals.

[0007] (5) Separation using intelligent control equipment, with representative equipment being sensor-based automatic separation devices (such as intelligent sight glasses + PLC control systems). The working principle involves real-time monitoring of the interface using optical, ultrasonic, and other detection technologies to automatically control valve opening and closing. This is primarily suitable for fine chemical processes requiring high separation precision, such as the production of pharmaceutical intermediates.

[0008] However, existing liquid-liquid separation equipment generally suffers from the following problems: 1) Insufficient efficiency and continuity: Mostly intermittent operation, long settling time, and high-speed centrifugation exacerbates emulsification, making it difficult to match continuous production. 2) Complex structure and high cost: Extraction towers are difficult to maintain, membranes require frequent cleaning and replacement, and centrifuges require special materials such as Hastelloy, making the equipment expensive. 3) Weak demulsification ability: Poor effect on stable emulsions, requiring the addition of additional demulsifiers; membrane separation is prone to pore clogging. 4) High energy consumption and environmental pressure: Centrifugation equipment has high power consumption, solvent loss rate >5%, and high VOC emissions; extractant volatilization and entrainment are serious, resulting in high recovery costs. 5) Poor automation adaptability: Relies on manual monitoring, making operation prone to errors; continuous equipment has limited adaptability to changes in material properties, requiring frequent parameter adjustments.

[0009] Therefore, it is necessary to develop an effective continuous liquid-liquid separation device, and it has a wide market prospect. Utility Model Content

[0010] The problems to be solved by this invention are: insufficient continuous separation efficiency and stability; complex equipment structure and high maintenance cost; high energy consumption and solvent loss; and insufficient entrainment and separation purity.

[0011] The purpose of this invention is to overcome the defects in the existing technology and achieve dynamic and continuous separation of the aqueous phase and the organic phase through structural optimization. A continuous liquid-liquid separation device is provided, characterized in that it includes a mixed phase inlet, a three-stage flow-guiding phase separation structure, a DCS control system, a light component liquid outlet 1, a light component liquid outlet 2, and a heavy component liquid outlet; the three-stage flow-guiding phase separation structure includes a mixed phase zone, a main phase separation zone, a heavy component liquid purification zone 1, and a heavy component liquid purification zone 2, with baffles provided between the two zones; baffles AB and BC are provided with holes for liquid to pass through; a baffle ab parallel to the bottom surface of the separation device is provided inside the mixed phase zone, the position of baffle ab is outside the holes on baffle AB, and it is connected to the bottom surface of the separation device; baffle ab is provided with holes; a baffle bc perpendicular to the bottom surface of the separation device is provided inside the main phase separation zone, baffle bc is vertically installed and fixed to baffles AB, baffles BC, and the bottom surface of the separation device; the light component liquid outlet 1 is located above the main phase separation zone, the light component liquid outlet 2 is located at the top of the heavy component liquid purification zone 2, and the heavy component liquid outlet is located at the upper outer side of the heavy component liquid purification zone 2.

[0012] As a further optimization of this technical solution, the height of baffle ab is 60cm, the height of baffles AB and BC is 100cm, the height of the holes on baffle AB is 65-95cm, the height of the holes on baffle BC is 0-20cm; the height of baffle bc is 95cm, the width of bc is 40cm, for overflow of light component liquid; the height of baffle CD is 90cm, for overflow of heavy component liquid.

[0013] As a further optimization of this technical solution, the mixed phase inlet (a-1) is connected to an inlet pipe with a nominal diameter of DN50, and a flow meter (FICQ) is installed on the inlet pipe to control the inflow velocity of the mixed phase to 0.1-1 m / s; the light component liquid outlet 1 (b-1) is connected to an outlet pipe with a nominal diameter of DN50, and the heavy component liquid outlet (c-1) is connected to an outlet pipe with a nominal diameter of DN25, and a flow meter (FICQ) is installed on the outlet pipe. The flow meter signal is connected to the DCS control system to control the flow velocity to 0.2-1 m / s; the slope of the outlet pipe is ≥1%.

[0014] As a further optimization of this technical solution, level gauges and density meters are installed on the sides of the main phase separation zone and the heavy component liquid refining zone to monitor the liquid level and density of the main phase separation zone and the heavy component liquid refining zone in real time; the signals from the level gauges and density meters are connected to the DCS control system to interlock and control the flow meter and valve opening.

[0015] As a further optimization of this technical solution, the level gauge is one of the following: laser level gauge, float level gauge, radar level gauge, capacitive level gauge, differential pressure level gauge, and ultrasonic level gauge.

[0016] As a further optimization of this technical solution, a solvent inlet is provided on the side wall of the mixed phase zone, which can be flushed with solvent for washing when necessary; real-time monitoring and sampling ports are provided for the light component liquid outlets 1 and 2 and the heavy component liquid outlet.

[0017] As a further optimization of this technical solution, an ultrasonic demulsification module can be added to the bottom of the mixed phase zone and inside the baffle ab for re-layering; when the liquid level fluctuation exceeds ±2mm, and the density difference is <0.2g / cm³ 3 At that time, the ultrasonic demulsification module will be activated.

[0018] As a further optimization of this technical solution, the separation device has dimensions of 1m × 1m × 1m and an effective volume of 0.8m³. 3 The processing capacity is 1-10m³. 3 / h.

[0019] As a further optimization of this technical solution, the main body of the separation device is made of 316L stainless steel; the contact interface is coated with polytetrafluoroethylene (PTFE) with a contact angle >110°; and the sealing material used in the separation device is a fluororubber sealing ring.

[0020] As a further optimization of this technical solution, the separation device is suitable for density differences ≥ 0.3 g / cm³. 3 The mixed phases with a viscosity ≤50mPa·s and pH 0~14 are separated.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] (1) High-efficiency continuous separation

[0023] 1.1 Gravity-driven stratification: Natural stratification is achieved in a static flow field by utilizing the density difference between light and heavy components.

[0024] 1.2 Multi-stage flow enhancement: A three-stage flow enhancement structure composed of baffles of different heights guides the fluid to form a stable laminar flow, shortening the stratification time to within 5 minutes.

[0025] 1.3 Precise liquid level control: Through the height difference design of the baffles between the two zones and the configuration of DN50 / DN25 pipes, dynamic balance of the two-phase interface is achieved, ensuring that the light components are discharged first and avoiding the entrainment of heavy components, thus achieving continuous and stable discharge.

[0026] (2) Low energy consumption and environmental protection

[0027] The liquid-liquid separation device of this application can achieve a separation efficiency of >99.9% without the need for power drive.

[0028] (3) Compact structure and low maintenance

[0029] The liquid-liquid separation device of this application is compact in size and can meet the needs of modern continuous production. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of a continuous liquid-liquid separation device according to the present invention; Explanation of reference numerals:

[0032] a-1, Mixed phase inlet; 1, Three-stage flow-guiding phase separation structure; b-1, Light component liquid outlet 1; b-2, Light component liquid outlet 2; c-1, Heavy component liquid outlet; A, Mixed phase zone; B, Main phase separation zone; C, Heavy component liquid purification zone 1; D, Heavy component purification zone 2; AB, Baffle; ab, Baffle; BC, Baffle; bc, Baffle; CD, Baffle; a-2, Solvent inlet; DT, Density meter; LIAS, Level gauge; FICQ, Flow meter; E, Bottom surface. Detailed Implementation

[0033] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] This invention provides a continuous liquid-liquid separation device, including a mixed phase inlet, a three-stage flow-guiding phase separation structure, a DCS control system, a light component liquid outlet, and a heavy component liquid outlet; the three-stage flow-guiding phase separation structure includes a mixed phase zone, a main phase separation zone, and a heavy component liquid refining zone. The separation device has dimensions of 1m × 1m × 1m (length × width × height), with an effective volume of 0.8m³. 3 The mixed-phase feed velocity is 0.3–0.9 m / s, and the throughput is 1–10 m³ / s. 3 / h. Applicable systems have a density difference ≥0.3g / cm³. 3 A mixed-phase system with a viscosity ≤50 mPa·s and pH 0~14.

[0036] The height of baffle ab is 60cm, the height of the hole on baffle ab is 60cm, the height of baffles AB and BC is 100cm, the height of the hole on baffle AB is 65-95cm, baffle ab is vertical and connected to the outside of the hole in baffle AB, the height of the hole on baffle BC is 0-20cm; the height of baffle bc is 95cm, the width of baffle bc is 40cm, for overflow of light component liquid; the height of baffle CD is 90cm, for overflow of heavy component liquid.

[0037] Example 1

[0038] A mixed solution containing 60% methyl tert-butyl ether and 40% water by mass is continuously introduced from one side into the mixed phase zone A of the liquid-liquid separator through mixed phase inlet a-1 (DN50). After initial settling and stratification, the solution is separated into layers. Since the density of methyl tert-butyl ether is lower than that of water (approximately 0.74 g / cm³), the solution will be separated into layers. 3 The density of water is 1.00 g / cm³. 3Methyl tert-butyl ether (MTBE) enters the main phase separation zone B through the holes in baffle AB, while the aqueous phase flows downwards into the main phase separation zone B through the bottom holes of baffle AB. In the main phase separation zone B, MTBE is on top and the aqueous phase is below, with MTBE flowing out through the light component liquid outlet b-1 to complete the separation. The aqueous phase flows through the holes at the bottom of the side plate in the main phase separation zone towards the heavy component purification zone 1. When the aqueous phase level rises to the height of the 900mm baffle, it passes over the baffle and enters the heavy component purification zone 2, flowing out through the nominal diameter DN25 pipe of the heavy component liquid outlet c-1 on the side to complete the separation. When the liquid level fluctuation of the level gauge in the heavy component purification zone exceeds ±2mm, it indicates that the MTBE entrained in the aqueous phase has risen to the top of the heavy component purification zone and flows out through the nominal diameter DN25 pipe of the light component liquid outlet b-2. Connecting the mixed phase inlet pipe allows for recirculation, stratification, and separation collection.

[0039] When the density difference of the densitometer signal between the main phase separation region and the heavy component purification region is <0.2 g / cm³ 3 At that time, the ultrasonic demulsification module installed at the bottom of the mixed phase region A is triggered to perform re-layering.

[0040] Because methyl tert-butyl ether (MTBE) and water have a significant density difference (0.26 g / ml), a residence time of 4–10 min is sufficient to ensure separation efficiency. Therefore, the mixed-phase feed flow rate was set at 0.3–0.9 m / s. Gas chromatography sampling and testing showed that the residual MTBE content at the heavy component outlet was ≤0.5 wt%, and the water content at the light component outlet was ≤0.3 wt%. The 95 cm high baffle prolonged the residence time of the aqueous phase, reducing the entrainment of MTBE.

[0041] Example 2

[0042] The dimethyl carbonate-water mixture consists of 60% dimethyl carbonate (organic phase) and 40% water (aqueous phase), is emulsifier-free (surfactant content <0.005%), contains trace amounts of methanol impurities (0.3% by mass, a byproduct of DMC synthesis in fine chemical industry), has a viscosity of 1.1 mPa·s (25℃), and a pH ≈ 6.9 (weakly neutral).

[0043] A mixture of dimethyl carbonate and water is introduced into the mixed phase zone A of the continuous stratification tank through a DN50 inlet pipe (mixed phase inlet a-1) from one side. After initial settling and stratification, the mixture is allowed to separate. Since dimethyl carbonate has a higher density than water (dimethyl carbonate density is approximately 1.07 g / cm³), the mixture is allowed to separate. 3 The density of water is 1.00 g / cm³. 3The aqueous phase enters the main phase separation zone B through the side holes of baffle AB, while dimethyl carbonate flows downwards into the main phase separation zone B through the lower holes of baffle AB. In the main phase separation zone B, the aqueous phase is on top, and the dimethyl carbonate is below. The aqueous phase crosses the 950mm high baffle BC and enters a small adjacent space, exiting from the nominal diameter DN50 pipe of the light component liquid outlet b-1, completing the separation. Dimethyl carbonate flows through the holes of baffle BC in the main phase separation zone towards the heavy component purification zone C. When the dimethyl carbonate level rises to the 90cm high baffle height, it crosses baffle CD and enters the heavy component purification zone D, exiting from the heavy component liquid outlet c-1 (DN25), completing the separation.

[0044] When the aqueous phase is entrained into the heavy component refining zone, it is discharged through the nominal diameter DN25 outlet of the light component outlet d-2. It can be returned to the mixed phase inlet (a-1) for further separation.

[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. The above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A continuous liquid-liquid separation device, characterized in that, The system includes a mixed phase inlet (a-1), a three-stage flow-guiding phase separation structure (1), a DCS control system, a light component liquid outlet 1 (b-1), a light component liquid outlet 2 (b-2), and a heavy component liquid outlet (c-1). The three-stage flow-guiding phase separation structure (1) includes a mixed phase zone (A), a main phase separation zone (B), a heavy component liquid refining zone 1 (C), and a heavy component refining zone 2 (D), with baffles (AB), (BC), and (CD) provided between the two zones. The baffles (AB) and (BC) are provided with holes for liquid to pass through. The mixed phase zone (A) is provided with a baffle parallel to the bottom surface (E). (ab), the baffle (ab) is located outside the hole on the baffle (AB); the baffle (ab) is provided with holes; the main phase separation zone (B) is provided with a baffle (bc) perpendicular to the bottom surface of the separation device, the baffle (bc) is vertically installed and fixed on the bottom surface (E) of the baffle (AB), the baffle (BC) and the separation device; the light component liquid outlet 1 (b-1) is located above the main phase separation zone (B), the light component liquid outlet 2 (b-2) is located at the top of the heavy component liquid purification zone 2; the heavy component liquid outlet (c-1) is located at the upper outer side of the heavy component liquid purification zone 2 (D).

2. The continuous liquid-liquid separation device according to claim 1, characterized in that, The height of the baffle (ab) is 60cm; the height of the baffles (AB) and (BC) is 100cm; the height of the holes in the baffle (AB) is 65-95cm; the height of the holes in the baffle (BC) is 0-20cm; the height of the baffle (bc) is 95cm and the width is 40cm, for overflow of the light component liquid; the height of the baffle (CD) is 90cm, for overflow of the heavy component liquid.

3. The continuous liquid-liquid separation device according to claim 1, characterized in that, The mixed phase inlet (a-1) is connected to an inlet pipe with a nominal diameter of DN50. A flow meter (FICQ) is installed on the inlet pipe to control the flow velocity of the mixed phase to 0.1-1 m / s. The light component liquid outlet 1 (b-1) is connected to an outlet pipe with a nominal diameter of DN50, and the heavy component liquid outlet (c-1) is connected to an outlet pipe with a nominal diameter of DN25. A flow meter (FICQ) is installed on the outlet pipe, and the flow meter signal is connected to the DCS control system to control the flow velocity at 0.2-1 m / s. The slope of the outlet pipe is ≥1%.

4. The continuous liquid-liquid separation device according to claim 1, characterized in that, Level gauges (LIAS) and densitometers (DT) are installed on the sides of the main phase separation zone (B) and the heavy component liquid refining zone (C and D) to monitor the liquid level and density in the main phase separation zone (B) and the heavy component liquid refining zone (C and D) in real time; the signals of the level gauges (LIAS) and densitometers (DT) are connected to the DCS control system to interlock and control the flow meter and valve opening.

5. A continuous liquid-liquid separation device according to claim 4, characterized in that, The level gauge (LIAS) is one of the following: laser level gauge, float level gauge, radar level gauge, capacitive level gauge, differential pressure level gauge, and ultrasonic level gauge.

6. A continuous liquid-liquid separation device according to claim 1, characterized in that, The sidewall of the mixed phase region (A) is also provided with a solvent inlet (a-2), which can be flushed with solvent for washing when necessary; the light component liquid outlet 1 (b-1), light component liquid outlet 2 (b-2) and heavy component liquid outlet (c-1) are all provided with real-time monitoring sampling ports.

7. A continuous liquid-liquid separation device according to claim 1, characterized in that, An ultrasonic demulsification module can be installed at the bottom of the mixed phase region (A) and inside the baffle (ab) for further stratification; when the liquid level fluctuation exceeds ±2mm, and the density difference is <0.2g / cm³, 3 At that time, the ultrasonic demulsification module will be activated.

8. A continuous liquid-liquid separation device according to claim 1, characterized in that, The separation device has dimensions of 1m × 1m × 1m and an effective volume of 0.8m³. 3 The processing capacity is 1-10m³. 3 / h.

9. A continuous liquid-liquid separation device according to claim 8, characterized in that, The main body of the separation device is made of 316L stainless steel; the contact interface is coated with polytetrafluoroethylene (PTFE) with a contact angle >110°; the sealing material used in the separation device is a fluororubber sealing ring.

10. A continuous liquid-liquid separation device according to claim 9, characterized in that, The separation device is suitable for density differences ≥ 0.3 g / cm³. 3 Separation of mixed phases with viscosity ≤50mPa·s and pH 0~14.

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