An apparatus and method for enhancing the multi-stage extraction and separation of dissolved and dispersed oils.

Abstract

This invention discloses an apparatus and method for enhanced multi-stage extraction and separation of dissolved and dispersed oils. The apparatus comprises a lobed enhanced mixing unit and an extraction separator connected in sequence, and a circulating pump connected between the extraction separator and the lobed enhanced mixing unit. The extraction separator includes a countercurrent extraction chamber, an extraction phase settling chamber located above the countercurrent extraction chamber, and an aqueous phase settling chamber located below the countercurrent extraction chamber. The interior of the countercurrent extraction chamber, from top to bottom, comprises a fiber demister bed, an aqueous phase distributor, a droplet generator, a particle extraction bed, and a support layer. Compared with traditional extraction towers, the apparatus of this invention has a compact structure, small footprint, fast extraction mass transfer, high extraction efficiency, low process resistance, and low energy consumption, making it suitable for the extraction of dissolved and dispersed oils in chemical, environmental protection, and other fields.

Description

Technical Field

[0001] This invention belongs to the chemical and environmental protection field of oily wastewater treatment, and specifically relates to an apparatus and method for enhancing the multi-stage extraction and separation of dissolved and dispersed oils. Background Technology

[0002] In petrochemical production processes, products and wastewater often contain dissolved and dispersed oil impurities. Effective removal of these contaminants is a key challenge in purification and wastewater treatment. Extraction, a widely used method, utilizes the differences in solubility of dissolved and dispersed oils in different solvents to transfer them from water to a solvent with higher solubility. The solvent is then separated from the water to remove the dissolved and dispersed oils. However, traditional extraction equipment suffers from insufficient mixing between the extractant and extracted phases, resulting in a small mass transfer area, low efficiency, large footprint, and long residence time.

[0003] CN112827216A discloses an apparatus and method for enhancing liquid-liquid extraction, which improves the efficiency of liquid-liquid extraction by jet mixing. However, the mixing and extraction section requires a high flow rate to utilize the rotating turbulent flow field of the spiral section, and the variable diameter section increases the pressure drop before and after, resulting in a large pressure drop loss when the liquid flows through the mixing and extraction section.

[0004] CN115040897A discloses an ultrasonic atomizing liquid-liquid extraction device. This device achieves the extraction purpose by atomizing and fully mixing the extractant and the sample liquid, avoiding the phenomenon of liquid emulsification. However, this device requires atomizing and cooling the two phases, consumes a lot of electricity, and is only suitable for small-scale extraction.

[0005] CN 113082765 A discloses a high-pressure extraction device and its usage method, which improves extraction efficiency by using pressurization and rotating flow field. However, the device requires bearing to drive rotation, resulting in high energy consumption. Furthermore, the pressurization process places high demands on the pressure resistance and safety of the device, making it unsuitable for applications with large extraction volumes. Summary of the Invention

[0006] To address the aforementioned problems in existing technologies, and to effectively enhance mass transfer rates and improve processing capacity without increasing floor space or energy consumption, this invention provides an apparatus and method for enhancing multi-stage extraction and separation of dissolved and dispersed oils.

[0007] The technical solution adopted in this invention is as follows:

[0008] An apparatus for enhancing the multi-stage extraction and separation of dissolved and dispersed oils, comprising a lobed enhanced mixing unit and an extraction separator connected in sequence, and a circulating pump connected between the extraction separator and the lobed enhanced mixing unit.

[0009] The extraction separator includes a countercurrent extraction chamber, an extraction phase settling chamber located above the countercurrent extraction chamber, and an aqueous phase settling chamber located below the countercurrent extraction chamber. The interior of the countercurrent extraction chamber is provided with, from top to bottom, a fiber demister bed, an aqueous phase distributor, a droplet generator, a particle extraction bed, and a support layer.

[0010] According to a preferred embodiment of the present invention, the fiber defoaming bed is located at the top of the countercurrent extraction chamber and is used to defoam the extract phase floating in the countercurrent extraction chamber, while allowing the small amount of residual water phase in the extract phase to coalesce, thereby achieving dehydration and separation of the extract phase.

[0011] The aqueous phase distributor is located below the fiber defoaming bed and is used to evenly distribute the wastewater entering the extraction separator before it enters the countercurrent extraction chamber.

[0012] The particulate extraction bed is located at the bottom of the countercurrent extraction chamber and is composed of stacked hydrophilic and lipophilic particles. It utilizes the aggregation and capture effect of hydrophilic and lipophilic particles to capture the downward-flowing fine extractant droplets in the aqueous phase, while simultaneously enhancing the extraction of dissolved and dispersed oils within the bed.

[0013] The droplet generator is positioned above the particle extraction bed and opposite to the aqueous phase distributor, and is used to disperse the extract phase into droplets before they enter the countercurrent extraction chamber.

[0014] The support layer is disposed at the bottom of the particle extraction bed and is used to support the particle extraction bed.

[0015] Furthermore, the aqueous phase distributor includes an aqueous phase guide pipe and an aqueous phase distribution plate that are interconnected. The front end of the aqueous phase guide pipe is connected to the wastewater inlet on the side wall of the countercurrent extraction chamber, and the rear end, after being bent, is connected to the aqueous phase distribution plate.

[0016] The water phase distribution plate includes a radially distributed annular segment and a radial support segment for supporting the annular segment; a number of columnar nozzles are uniformly distributed on the lower surface of the annular segment and the radial support segment.

[0017] Preferably, the height of the columnar nozzle is 1 to 10 cm, and the inner diameter of the nozzle is 0.2 to 10 mm.

[0018] According to a preferred embodiment of the present invention, the droplet generator includes an extractable phase guide tube and an extractable phase distribution plate that are interconnected. The front end of the extractable phase guide tube is connected to the extractable phase inlet on the side wall of the countercurrent extraction chamber, and the rear end, after being bent, is connected to the extractable phase distribution plate.

[0019] The extraction phase distribution disk includes a radially distributed annular segment and a radial support segment for supporting the annular segment; a number of droplet generating columns are uniformly distributed on the lower surface of the annular segment and the radial support segment.

[0020] According to a preferred embodiment of the present invention, the droplet generating column includes a tapering section, a mixing section, a diffusing section, and a constant-diameter section arranged sequentially from the inlet to the outlet, wherein:

[0021] The contraction angle β of the tapering section is 15° to 45°; several columnar conical openings are evenly distributed on the outer wall of the mixing section, and the cone angle θ of the cone segment at the front end of the columnar conical opening is 10° to 60°; the expansion angle γ of the expanding section is 5° to 20°.

[0022] Preferably, the height of the droplet generating column is 1 to 10 cm; the inner diameter of the equal-diameter section of the droplet generating column is 0.3 to 5 mm.

[0023] According to a preferred embodiment of the present invention, the particulate extraction bed is composed of randomly stacked hydrophilic and lipophilic particles.

[0024] Preferably, the stacking ratio of the hydrophilic and lipophilic particles is 1:4 to 4:1, and the porosity of the particle extraction bed is 20% to 90%.

[0025] According to a preferred embodiment of the present invention, the main body of the aqueous sedimentation chamber is a cylindrical section, with an aqueous phase outlet at the bottom and a tapered section at the top, so that the upper opening matches the bottom opening of the countercurrent extraction chamber, and an extraction phase outlet is provided at the tapered section.

[0026] The main body of the extraction phase settling chamber is also a cylindrical section, with a tapering section at the bottom so that its bottom opening matches the upper opening of the countercurrent extraction chamber, and the tapering section has an extraction phase outlet.

[0027] Preferably, the contraction angle α of the converging sections of the aqueous phase settling chamber and the extractive phase settling chamber is 15° to 60°.

[0028] According to a preferred embodiment of the present invention, the petal-shaped enhanced mixing unit includes a T-shaped jet mixing chamber, a jet tip cone ejector, and a petal-shaped turbulence mixing chamber, wherein:

[0029] The horizontal section of the T-shaped jet mixing chamber has an aqueous phase inlet at one end and a mixed liquid outlet at the other end. Its vertical section is the extractable phase inlet. The aqueous phase inlet is connected to the aqueous phase outlet of the production separator, and the mixed liquid outlet is connected to the petal-shaped turbulent mixing chamber. The front end of the jet top cone injector is located inside the extractable phase inlet, and the outlet of the petal-shaped turbulent mixing chamber is connected to the wastewater inlet of the countercurrent extraction chamber.

[0030] Furthermore, the jet top cone ejector is integrally composed of a hemispherical section at the front end and a cylindrical section at the rear end. The rear end of the cylindrical section is the extraction phase inlet, and a cylindrical injection port is formed at the center of the hemispherical section. The interior of the jet top cone ejector, from the circulating extraction phase inlet to the cylindrical injection port, sequentially includes a converging port, a expanding port, and a top cone structure supported by the ejector's inner wall.

[0031] The tapering angle β1 of the tapering opening is 15° to 45°; the flaring angle γ1 of the flaring opening is 5° to 20°.

[0032] The cone apex angle θ1 of the top cone structure facing the extraction phase outlet is 45° to 120°, and the cone tail angle θ2 facing the extraction phase inlet is 15° to 30°.

[0033] A method for enhancing the multi-stage extraction and separation of dissolved and dispersed oils, employing the aforementioned apparatus for enhancing the multi-stage extraction and separation of dissolved and dispersed oils, includes the following steps:

[0034] S1: The aqueous phase to be treated flows into the petal-type enhanced mixing unit and then into the extraction separator. It is then evenly distributed by the aqueous phase distributor and enters the countercurrent extraction chamber, where it flows from top to bottom.

[0035] S2: The extractable phase enters the droplet generator through the inlet of the countercurrent extraction chamber. When it passes through the droplet generating column of the droplet generator, the negative pressure generated in the droplet generating column draws in the external aqueous phase through the column cone and mixes it with the extractable phase. At the same time, when the extractable phase flows from the droplet generating column into the countercurrent extraction chamber, a large number of uniform extractable phase droplets are generated, which are further mixed and extracted with the aqueous phase in the countercurrent extraction chamber.

[0036] S3: The water and the extractable phase carried in the water in the countercurrent extraction chamber pass further downward through the particle extraction bed. The aggregation and capture effect of the hydrophilic and lipophilic particles causes the extractable phase droplets to grow. At the same time, the extractable phase droplets adhering to the particle bed have a relative velocity with the water. Under the shear force of the water phase, the extractable phase droplets circulate and flow inside the extractable phase droplets, which enhances the capture of dissolved and dispersed oils in the water phase.

[0037] S5: The extract phase located in the countercurrent extraction chamber floats up and is defoamed by the fiber defoaming bed. At the same time, the fiber defoaming bed causes the small amount of residual water phase in the extract phase to coalesce, thereby achieving dehydration and separation of the extract phase. The defoamed and dehydrated extract phase enters the extract phase settling chamber.

[0038] S4: The aqueous phase passing through the particle extraction bed enters the aqueous phase settling chamber and flows out through the aqueous phase outlet, resulting in purified water with dissolved and dispersed oil removed; the extract phase passing through the particle extraction bed enters the aqueous phase settling chamber and floats and accumulates at the top of the aqueous phase settling chamber in the tapered section.

[0039] S6: The tapered section floating and accumulating at the bottom of the aqueous phase settling chamber and the extractive phase located in the extractive phase settling chamber are pumped by the circulating pump. Part of the extractive phase is regenerated, and the other part is used as the circulating extractive phase input jet top cone ejector.

[0040] S7: After the circulating extractable phase enters the jet top cone ejector, it generates fine extractable phase droplets that mix evenly with the aqueous phase in the jet mixing chamber, while simultaneously extracting some of the dissolved and dispersed oils in the water. Then, it enters the petal-type turbulent mixing chamber to enhance the mixing and extraction effect.

[0041] Preferably, the droplet dispersion particle size generated after the extractant phase passes through the extractant phase droplet generator is 0.05 to 2 mm.

[0042] Preferably, the circulating extractable phase is dispersed into droplets with a particle size of 10-200 μm after passing through the jet top cone ejector, and the extractable phase is dispersed into droplets with a particle size of 10-50 μm after passing through the petal-shaped turbulent mixing chamber.

[0043] The present invention has the following beneficial effects:

[0044] 1. This invention provides an apparatus and method for enhancing multi-stage extraction and separation of dissolved and dispersed oils by strengthening mixing and mass transfer. The apparatus for multi-stage extraction of dissolved and dispersed oils includes an extraction separator and a lobed enhanced mixing unit. The extraction separator premixes the extract phase with the aqueous phase through an internal droplet generator, and then further improves the extraction effect by using countercurrent mixing. Combined with the aggregation and growth of extract phase droplets by the particulate extraction bed, the extract phase droplets circulate under the shear force of the aqueous phase, capturing the dissolved and dispersed oils in the aqueous phase and extracting them deeply. The extract phases floating and agglomerated in the aqueduct section of the aqueous phase settling chamber and the extract phase settling chamber are pumped, and part of the extract phase is regenerated, while the other part is input as a circulating extract phase into the jet top cone ejector. The circulating extract phase entering the top cone ejector is mixed with the aqueous phase in the jet mixing chamber, simultaneously extracting part of the dissolved and dispersed oils in the water. Then, it enters the lobed turbulent mixing chamber to enhance the mixing and extraction effect.

[0045] 2. Compared with traditional extraction towers, the device of the present invention has a compact structure, small footprint, fast extraction mass transfer, high extraction efficiency, low process resistance and low energy consumption, and is suitable for the extraction of dissolved oil and dispersed oil in chemical, environmental protection and other fields. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the structure of the device for enhanced multi-stage extraction and separation of dissolved and dispersed oils according to the present invention.

[0047] Figure 2 yes Figure 1 A schematic diagram of the extraction separator structure.

[0048] Figure 3A and 3B These are the front view and top view of the water phase distributor.

[0049] Figure 4A and 4B These are the front view and top view of the droplet generator, respectively.

[0050] Figure 5 This is a schematic diagram of the droplet generation column structure.

[0051] Figure 6 This is a schematic diagram of the internal circulation extraction of the extractant phase droplets within the countercurrent extraction chamber.

[0052] Figure 7 This is a schematic diagram of droplet aggregation and capture of dissolved and dispersed oil within a particle extraction bed.

[0053] Figure 8 This is a schematic diagram of a petal-shaped reinforced hybrid unit structure.

[0054] Figure 9 This is a schematic diagram of the jet top cone ejector structure.

[0055] Figure 10 This is a schematic diagram of a apex cone structure. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to embodiments. It should be understood that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-substantial improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0057] Example 1: Apparatus and method for enhanced multi-stage extraction and separation of dissolved and dispersed oils

[0058] 1.1 Enhanced Multi-stage Extraction and Separation Unit for Dissolved and Dispersed Oils

[0059] like Figure 1 As shown, the enhanced dissolving oil and dispersed oil multi-stage extraction and separation device of the present invention includes a petal-type enhanced mixing unit 2 and an extraction separator 1 connected in sequence, and a circulation pump 3 connected between the extraction separator 1 and the petal-type enhanced mixing unit 2.

[0060] like Figure 2 As shown, the extraction separator 1 includes a countercurrent extraction chamber 11, an extraction phase settling chamber 18 disposed above the countercurrent extraction chamber 11, and an aqueous phase settling chamber 16 disposed below the countercurrent extraction chamber 11; the interior of the countercurrent extraction chamber 11 is provided with, from top to bottom, a fiber demister bed 17, an aqueous phase distributor 12, a droplet generator 13, a particle extraction bed 14, and a support layer 15, wherein:

[0061] The fiber defoaming bed 17 is located at the top of the countercurrent extraction chamber 11 and is used to defoam the extract phase floating in the countercurrent extraction chamber 11, while allowing the small amount of residual water phase in the extract phase to coalesce, thereby achieving dehydration and separation of the extract phase.

[0062] The aqueous phase distributor 12 is located below the fiber defoaming bed 17 and is used to distribute the wastewater entering the extraction separator 1 evenly before it enters the countercurrent extraction chamber 11.

[0063] The droplet generator 13 is positioned above the particle extraction bed 14 and opposite the aqueous phase distributor 12. It is used to disperse the extract phase into droplets before they enter the countercurrent extraction chamber 11.

[0064] The particulate extraction bed 14 is located at the bottom of the countercurrent extraction chamber 11 and is composed of stacked hydrophilic and lipophilic particles. It utilizes the aggregation and capture effect of hydrophilic and lipophilic particles to capture the downward-flowing fine extractant droplets in the aqueous phase, while simultaneously enhancing the extraction of dissolved and dispersed oils within the bed.

[0065] The support layer 15 is disposed at the bottom of the particle extraction bed 14 and is used to support the particle extraction bed 14.

[0066] Furthermore, in combination Figure 3A As shown, the aqueous phase distributor 12 includes an aqueous phase guide pipe 121 and an aqueous phase distribution plate 122 that are interconnected. The front end of the aqueous phase guide pipe 121 is connected to the wastewater inlet on the side wall of the countercurrent extraction chamber 11, and the rear end, after being bent, is connected to the aqueous phase distribution plate 122. Figure 3B As shown, the water phase distribution disk 122 includes a radially distributed annular segment 123 and a radial support segment 124 for supporting the annular segment 123; a plurality of columnar nozzles 125 are uniformly distributed on the lower surface of the annular segment 123 and the radial support segment 124; preferably, the height of the columnar nozzles 125 is 1 to 10 cm, and the inner diameter of the nozzles is 0.2 to 10 mm.

[0067] Furthermore, in combination Figure 4A As shown, the droplet generator 13 includes an extractable phase guide pipe 131 and an extractable phase distribution disk 132 that are interconnected. The front end of the extractable phase guide pipe 131 is connected to the extractable phase inlet on the side wall of the countercurrent extraction chamber 11, and the rear end, after being bent, is connected to the extractable phase distribution disk 132. Figure 4B As shown, the extraction phase distribution disk 132 includes a radially distributed annular segment 133 and a radial support segment 134 for supporting the annular segment 133; a plurality of droplet generating columns 135 are uniformly distributed on the lower surface of the annular segment 133 and the radial support segment 134.

[0068] Furthermore, such as Figure 5As shown, the droplet generating column 135 includes a tapering section 136, a mixing section 137, a expanding section 139, and a constant-diameter section 140 arranged sequentially from the inlet to the outlet. The tapering angle β of the tapering section 136 is 15° to 45°. A plurality of columnar conical openings 138 are evenly distributed on the outer wall of the mixing section 137, and the cone angle θ of the cone segment at the front end of the columnar conical opening 138 is 10° to 60°. The expanding angle γ of the expanding section 139 is 5° to 20°. The height of the droplet generating column 135 is 1 to 10 cm. The inner diameter of the constant-diameter section 140 of the droplet generating column 135 is 0.3 to 5 mm.

[0069] like Figure 6 As shown, the extract phase droplets in the countercurrent extraction chamber 11 are subjected to shearing action by the countercurrent aqueous phase, which triggers internal circulation of the droplets. The extract phase droplets continuously renew their cross-sections to enhance the extraction process.

[0070] Furthermore, the particulate extraction bed 14 is composed of randomly stacked hydrophilic and oleophilic particles. The hydrophilic particles can be selected from quartz sand, glass sand, stainless steel, etc.; the oleophilic particles can be selected from PTFE, nylon, polypropylene, etc.; preferably, the stacking ratio of the hydrophilic and oleophilic particles is 1:4 to 4:1; the porosity of the particulate extraction bed 14 is 20% to 90%.

[0071] like Figure 7 As shown, in the particle extraction bed 14, the mixture of the extractant phase and the aqueous phase flows from top to bottom. The extractant phase droplets adhere to the microchannel walls of the hydrophilic and oleophilic particle bed, agglomerating and growing. Simultaneously, a velocity difference is generated between the extractant phase droplets and the aqueous phase. Under the shearing action of the aqueous phase, an internal circulation of the extractant phase is triggered, and the extractant phase droplets continuously renew and extract the interface.

[0072] Back Figure 2 The main body of the aqueous sedimentation chamber 16 is a cylindrical section with an aqueous outlet at the bottom and a tapered section at the top, so that the upper opening matches the bottom opening of the countercurrent extraction chamber 11, and the tapered section has an extraction phase outlet.

[0073] Furthermore, the main body of the extraction phase settling chamber 18 is also a cylindrical section, with a tapering section at the bottom so that its bottom opening matches the upper opening of the countercurrent extraction chamber 11, and an extraction phase outlet is provided at the tapering section.

[0074] Preferably, the contraction angle α of the contraction section of the aqueous phase settling chamber 16 and the extractive phase settling chamber 18 is 15° to 60°.

[0075] like Figure 8As shown, the petal-shaped enhanced mixing unit 2 includes a T-shaped jet mixing chamber 21, a jet top cone ejector 22, and a petal-shaped turbulent mixing chamber 23. The horizontal section of the T-shaped jet mixing chamber 21 has an aqueous phase inlet 211 at one end and a mixed liquid outlet 213 at the other end. Its vertical section is an extractable phase inlet 212. The mixed liquid outlet 213 is connected to the petal-shaped turbulent mixing chamber inlet 231. The front end of the jet top cone ejector 22 is located inside the extractable phase inlet 212. The outlet 234 of the petal-shaped turbulent mixing chamber 23 is connected to the wastewater inlet of the countercurrent extraction chamber 11.

[0076] Furthermore, such as Figure 9 As shown, the jet top cone ejector 22 is integrally composed of a hemispherical section at the front end and a cylindrical section at the rear end. The rear end of the cylindrical section is the extraction phase inlet, and a cylindrical injection port 225 is opened at the center of the hemispherical section. The interior of the jet top cone ejector 22, from the circulating extraction phase inlet to the cylindrical injection port 225, is sequentially provided with a tapering orifice 221, a diverging orifice 222, and a top cone structure 223 set by means of a support structure 224 on the inner wall of the ejector. The tapering angle β1 of the tapering orifice 221 is 15° to 45°; the diverging angle γ1 of the diverging orifice 222 is 5° to 20°. Figure 10 As shown, the cone apex angle θ1 of the top cone structure 223 facing the extraction phase outlet is 45° to 120°, and the cone tail angle θ2 facing the extraction phase inlet is 15° to 30°.

[0077] Furthermore, returning to Figure 8 The flap-shaped turbulence mixing chamber 23 is provided with alternating backflow flaps 232 and frontflow flaps 233. Figure 8 The arrows in the diagram indicate the direction of the mixed flow.

[0078] 1.2 Enhanced Multi-stage Extraction and Separation Method for Dissolved and Dispersed Oils

[0079] The enhanced multi-stage extraction and separation method for dissolved and dispersed oils using the above-mentioned apparatus includes the following steps:

[0080] S1: The aqueous phase to be treated flows into the petal-type enhanced mixing unit 2 and enters the extraction separator 1 in sequence. Then, it is evenly distributed by the aqueous phase distributor 12 and enters the countercurrent extraction chamber 11, where it flows from top to bottom in the countercurrent extraction chamber 11.

[0081] S2: The extractable phase enters the droplet generator 13 through the inlet of the countercurrent extraction chamber 11. When it passes through the droplet generating column 135 of the droplet generator 13, the external aqueous phase can be drawn in through the column cone 138 by the negative pressure generated in the droplet generating column 135 and mixed with the extractable phase. At the same time, when the extractable phase flows into the countercurrent extraction chamber 11 from the droplet generating column 135, a large number of uniform extractable phase droplets will be generated and further mixed with the aqueous phase in the countercurrent extraction chamber 11 for extraction.

[0082] S3: The extract phase located in the countercurrent extraction chamber 11 floats up and is defoamed by the fiber defoaming bed 17. At the same time, the fiber defoaming bed 17 can cause the small amount of residual water phase in the extract phase to coalesce, thereby achieving dehydration and separation of the extract phase. The defoamed and dehydrated extract phase enters the extract phase settling chamber 18.

[0083] S4: The water and the extract phase carried in the water in the countercurrent extraction chamber 11 further pass downward through the particle extraction bed 14. The extract phase droplets grow by the aggregation and capture effect of the hydrophilic and lipophilic particles. At the same time, the extract phase droplets adhering to the particle extraction bed 14 have a relative velocity with the water. Under the shear force of the water phase, the extract phase droplets circulate and capture the dissolved oil and dispersed oil in the water phase.

[0084] S5: The aqueous phase passing through the particle extraction bed 14 enters the aqueous phase settling chamber 16 and flows out through the aqueous phase outlet to obtain purified water with dissolved and dispersed oil removed; the extract phase passing through the particle extraction bed 14 enters the aqueous phase settling chamber 16 and floats and gathers at the top of the aqueous phase settling chamber 16 in the tapered section.

[0085] S6: The tapered section floating and accumulating at the bottom of the aqueous phase settling chamber 16 and the extractive phase located in the extractive phase settling chamber 18 are pumped by the circulating pump 43. Part of the extractive phase is regenerated, and the other part is used as the circulating extractive phase input jet top cone ejector 22.

[0086] S7: After the circulating extractable phase enters the jet top cone ejector 22, it generates fine extractable phase droplets that mix evenly with the water phase in the jet mixing chamber 21, while simultaneously extracting some of the dissolved and dispersed oils in the water. Then, it enters the petal-type turbulent mixing chamber 23 to enhance the mixing and extraction effect.

[0087] Furthermore, the droplet dispersion particle size generated after the extract phase passes through the extract phase droplet generator 13 is 0.05 to 2 mm.

[0088] Furthermore, after passing through the jet top cone ejector 22, the circulating extractable phase is dispersed into droplets with a particle size of 10 to 200 μm, and after passing through the petal-shaped turbulent mixing chamber 23, the extractable phase is dispersed into droplets with a particle size of 10 to 50 μm.

[0089] Example 2

[0090] This embodiment uses the apparatus and method described in Example 1 to extract naphthalene and phenol from wastewater. The extractant phase is n-hexane, and the extracted phase is an aqueous solution containing naphthalene and phenol. The concentration of naphthalene is 30 mg / L, and the concentration of phenol is 60 mg / L. The experimental apparatus has a processing capacity of 1.2 m³ / L. 3 / h.

[0091] The experiment maintained a flow ratio of 10:1 for the aqueous phase and the extractant phase. The extraction effect was investigated under different flow rates of the extracted phase. The concentrations of residual naphthalene and phenol in the water were measured to evaluate the extraction effect. The results are shown in Table 1 below:

[0092] Table 1. Extraction effect at different extractable phase flow rates

[0093]

[0094] Depend on Figure 1 The results show that as the flow rate of the extracted phase increases, the extraction efficiency first gradually increases. When the flow rate of the extracted phase reaches 400 L / h, the extraction efficiency of naphthalene and phenol reaches the highest, at 88.47% and 87.26%, respectively. Subsequently, as the flow rate of the extracted phase increases, the extraction efficiency decreases.

[0095] Example 3

[0096] This embodiment uses the apparatus and method described in Example 1 to extract dissolved and dispersed oils from coking wastewater, wherein the extractant is benzene. The total oil content of the coking wastewater is 500–1000 mg / L, and the COD value is 11000–24000 mg / L, including approximately 84% dissolved oils of phenols, indoles, and quinolines, and approximately 16% dispersed oils of alkanes and polycyclic aromatic hydrocarbons. The flow ratio of extractant to coking wastewater is 1:10. After extraction and separation, the coking wastewater is heated to 90–100°C and evaporated for 30 minutes to remove benzene.

[0097] After treatment with the above-mentioned device and method, all dispersed oil in the coking wastewater was removed, and the total oil content of the coking wastewater was reduced to less than 200 mg / L and the COD value was less than 7000 mg / L, indicating that the technology has a good extraction and separation effect on dissolved and dispersed oil in coking wastewater.

Claims

1. An apparatus for intensifying the separation of dissolved and dispersed oil by multistage extraction, characterized in that, The device for multi-stage extraction and separation of enhanced dissolved oil and dispersed oil comprises a petal-shaped enhanced mixing unit and an extractor separator connected in sequence, and a circulating pump connected between the extractor separator and the petal-shaped enhanced mixing unit; The extractor separator comprises a countercurrent extraction chamber, an extraction phase settling chamber arranged above the countercurrent extraction chamber, and a water phase settling chamber arranged below the countercurrent extraction chamber; the inside of the countercurrent extraction chamber is sequentially provided from top to bottom with a fiber defoaming bed layer, a water phase distributor, a droplet generator, a particle extraction bed layer, and a support layer; The petal-shaped enhanced mixing unit comprises a T-shaped jet mixing chamber, a jet top cone injector, and a petal-shaped turbulence mixing chamber; one end of the horizontal section of the T-shaped jet mixing chamber is a water phase inlet, the other end is a mixed liquid outlet, the vertical section is an extraction phase inlet, the mixed liquid outlet is connected with the petal-shaped turbulence mixing chamber, the front end of the jet top cone injector is located in the extraction phase inlet, and the outlet of the petal-shaped turbulence mixing chamber is communicated with the water phase distributor; The droplet generator comprises an extraction phase guide pipe and an extraction phase distribution disc communicated with each other; the front end of the extraction phase guide pipe is communicated with the extraction phase inlet on the side wall of the countercurrent extraction chamber, and the rear end after being bent is communicated with the extraction phase distribution disc; the extraction phase distribution disc comprises a radial annular segment and a radial support segment for supporting the radial annular segment; the lower surfaces of the radial annular segment and the radial support segment are uniformly provided with a plurality of droplet generation columns; the droplet generation column comprises a tapering segment, a mixing segment, an expanding segment, and a constant diameter segment arranged in sequence from the inlet to the outlet, and a plurality of column cone ports are uniformly distributed on the outer wall of the mixing segment.

2. The device for multi-stage extraction and separation of enhanced dissolved oil and dispersed oil according to claim 1, characterized in that: The fiber defoaming bed layer is located at the top of the countercurrent extraction chamber, is used for defoaming the extraction phase floating up in the countercurrent extraction chamber, and allows a small amount of residual water phase in the extraction phase to gather, so as to realize the dehydration separation of the extraction phase; The water phase distributor is arranged below the fiber defoaming bed layer, is used for uniformly distributing the sewage entering the extractor separator into the countercurrent extraction chamber; The particle extraction bed layer is located at the bottom of the countercurrent extraction chamber, is stacked by hydrophilic and oleophilic particles, captures the downward micro-extraction agent droplets in the water phase by using the coalescence capture effect of the hydrophilic and oleophilic particles, and strengthens the extraction of the enhanced dissolved oil and dispersed oil in the bed layer; The droplet generator is arranged above the particle extraction bed layer and opposite to the water phase distributor, is used for dispersing the extraction phase into droplets and then entering the countercurrent extraction chamber; The support layer is arranged at the bottom of the particle extraction bed layer, and is used for supporting the particle extraction bed layer.

3. The device for multi-stage extraction and separation of enhanced dissolved oil and dispersed oil according to claim 1, characterized in that: The water phase distributor comprises a water phase guide pipe and a water phase distribution disc communicated with each other; the front end of the water phase guide pipe is communicated with the sewage inlet on the side wall of the countercurrent extraction chamber, and the rear end after being bent is communicated with the water phase distribution disc. The water phase distribution disc comprises radially distributed circular ring segments and radial support segments for supporting the circular ring segments; the lower surfaces of the circular ring segments and the radial support segments are uniformly distributed with a plurality of columnar nozzles.

4. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil according to claim 3, wherein The height of the columnar nozzle is 1-10 cm, and the inner diameter of the nozzle is 0.2-10 mm.

5. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil according to claim 1, wherein In the liquid droplet generating column, the taper angle β of the tapered segment is 15-45°; the taper angle θ of the taper segment at the front end of the columnar nozzle is 10-60°; and the expansion angle γ of the expanding segment is 5-20°.

6. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil according to claim 1 or 5, wherein The height of the liquid droplet generating column is 1-10 cm; and the inner diameter of the constant diameter segment of the liquid droplet generating column is 0.3-5 mm.

7. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil of claim 1, wherein The stacking ratio of the hydrophilic and oleophilic particles of the particle extraction bed is 1:4-4:1, and the porosity of the particle extraction bed is 20%-90%.

8. The device for multi-stage extraction and separation of enhanced dissolved oil and dispersed oil according to claim 1, characterized in that: The main body of the water phase settling chamber is a cylindrical segment, the bottom of which is provided with a water phase outlet, and the top thereof is formed with a tapered segment so that the upper end opening thereof matches the bottom opening of the countercurrent extraction cavity, and the tapered segment is provided with an extraction phase outlet; The main body of the extraction phase settling chamber is also a cylindrical segment, the bottom of which is formed with a tapered segment so that the bottom opening thereof matches the upper end opening of the countercurrent extraction cavity, and the tapered segment is provided with an extraction phase outlet.

9. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil according to claim 8, wherein The taper angle α of the tapered segments of the water phase settling chamber and the extraction phase settling chamber is 15-60°.

10. The apparatus for multi-stage separation of enhanced solvated oil and dispersed oil of claim 1, wherein, The jet top cone injector is composed of a hemispherical segment at the front end and a column segment at the rear end, the rear end of the column segment is an extraction phase inlet, and the center of the hemispherical segment is provided with a columnar injection port; the inside of the jet top cone injector is sequentially provided with a tapered port, an expanding port, and a top cone structure by means of the support structure of the inner wall of the injector from the circulating extraction phase inlet to the columnar injection port, wherein: The taper angle β1 of the tapered port is 15-45°; and the expansion angle γ1 of the expanding port is 5-20°; The top cone angle θ1 of the top cone structure towards the extraction phase outlet is 45-120°, and the tail cone angle θ2 towards the extraction phase inlet is 15-30°.

11. A method for intensifying multi-stage extraction separation of dissolved and dispersed oil, using the apparatus for intensifying multi-stage extraction separation of dissolved and dispersed oil according to any one of claims 1 to 10, characterized in that, The method comprises the following steps: S1: the water phase to be treated flows into the extraction separator through the petal-shaped enhanced mixing unit in sequence, and then is uniformly distributed into the countercurrent extraction cavity by the water phase distributor, and flows from top to bottom in the countercurrent extraction cavity; S2: the extraction phase enters the liquid droplet generator through the inlet of the countercurrent extraction cavity, and when passing through the liquid droplet generating column of the liquid droplet generator, the negative pressure generated in the liquid droplet generating column is used to suck the external water phase into the columnar nozzle and mix with the extraction phase, at the same time, when the extraction phase flows into the countercurrent extraction cavity from the liquid droplet generating column, a large number of uniform extraction phase droplets are generated, which further mix with the water phase in the countercurrent extraction cavity for extraction; S3: the water in the countercurrent extraction cavity and the extraction phase carried by the water further pass through the particle extraction bed, the coalescence and capture effect of the hydrophilic and oleophilic particles is used to make the extraction phase droplets grow, and the extraction phase droplets adhered to the particle extraction bed cause internal circulation flow of the extraction phase droplets under the shearing force of the water phase due to the relative velocity between the extraction phase droplets and the water, thereby enhancing the capture of dissolved oil and dispersed oil in the water phase. S4: The extraction phase in the counter-current extraction chamber is defoamed by the fiber defoaming bed, and the fiber defoaming bed makes the residual small amount of water phase in the extraction phase converge, so as to realize the dehydration separation of the extraction phase; the extraction phase after defoaming and dehydration enters the extraction phase settling chamber; S5: The water phase passing through the particle extraction bed enters the water phase settling chamber and flows out from the water phase outlet, so as to obtain purified water in which the dissolved oil and the dispersed oil are removed; The extraction phase passing through the particle extraction bed enters the water phase settling chamber and floats and converges at the top of the water phase settling chamber; S6: The extraction phase floating and converging at the top of the water phase settling chamber and the extraction phase in the extraction phase settling chamber are pumped by a circulating pump, part of the extraction phase is regenerated or sent to a device, and the other part is input into the jet top cone injector as a circulating extraction phase; S7: The circulating extraction phase enters the jet top cone injector, and fine extraction phase droplets are generated in the jet mixing chamber and mixed with the water phase uniformly, so as to extract part of the dissolved oil and the dispersed oil in the water phase, and then enter the petal turbulence mixing chamber to strengthen the mixing extraction effect.

12. The method of multi-stage extractive separation according to claim 11, wherein, The droplet dispersion particle size of the extraction phase generated after passing through the extraction phase droplet generator is 0.05-2 mm.

13. The method of multi-stage extractive separation according to claim 11, wherein, The circulating extraction phase is dispersed into droplets with a particle size of 10-200 μm after passing through the jet top cone injector, and the extraction phase is dispersed into droplets with a particle size of 10-50 μm after passing through the petal turbulence mixing chamber.

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