Efficient separation system of three-phase components of oily sludge and separation method thereof

Abstract

The application discloses a high-efficiency separation system of three-phase components of oily sludge and a separation method thereof. The system comprises a homogenizing conditioning tank for dilution and viscosity reduction, a demulsification unit for chemical agent demulsification and thermal vibration and agglomeration demulsification, a separation unit for three-phase separation, and a recovery unit for recovering oil liquid, waste water and oily sludge waste residue. The oily sludge inlet of the homogenizing conditioning tank is communicated with the oily sludge outlet of an oily sludge storage tank, the water inlet of the homogenizing conditioning tank is communicated with the water outlet of a waste water heating tank, the oily sludge outlet of the homogenizing conditioning tank is communicated with the oily sludge inlet of the demulsification unit, the oily sludge outlet of the demulsification unit is communicated with the oily sludge inlet of the separation unit, and the oil phase, water phase and oily sludge solid phase outlets of the separation unit are respectively communicated with the oil phase, water phase and oily sludge solid phase inlets of the recovery unit. The oily sludge is destabilized by using a multi-stage reinforced synergistic demulsification mode, and is subjected to solid-liquid separation and oil-water separation, so that high-efficiency separation of three-phase components of the oily sludge is realized.

Description

Technical Field

[0001] This invention relates to the field of oily sludge treatment technology, and in particular to a highly efficient separation system and method for the three-phase components of oily sludge. Background Technology

[0002] With the high-quality development of the national economy, the demand for petroleum resources is constantly increasing. Simultaneously, the production of oily sludge solid waste from oil extraction, transportation, storage, and refining processes is also continuously rising. Currently, the estimated annual production of oily sludge in my country's petrochemical industry exceeds 6 million tons, with a cumulative total inventory reaching 143 million tons. Even a medium-sized refinery produces over 30,000 tons of oily sludge annually. The treatment of oily sludge has long been a difficult problem for petrochemical enterprises, posing a serious threat to the environment and human health.

[0003] Based on their origin, oily sludge can be classified into oilfield sludge, storage and transportation sludge, tank bottom sludge, refinery sludge, and accident sludge. On one hand, oily sludge mainly contains three categories of components: petroleum hydrocarbons (especially polycyclic aromatic hydrocarbons), heavy metals, and pathogenic microorganisms. Typical oily sludge contains 15%–90% oil, 20%–70% water, and 5%–45% solids. The oil phase contains high concentrations of aromatic hydrocarbons, saturated hydrocarbons, resins, and asphaltenes, making it highly valuable for resource utilization. On the other hand, oily sludge is usually a semi-solid waste composed of water-in-oil emulsions, oil-in-water emulsions, and suspended solids. Generally, oily sludge contains fine, flocculent particles with a high water-holding capacity. Furthermore, the solid particles, oil, and water form a stable emulsion structure, resulting in high viscosity and difficulty in sedimentation, making it challenging to treat.

[0004] Currently, there are still many problems in the existing oil sludge separation process, such as low oil phase recovery rate after treatment, high oil and water content in solid waste residue, and mediocre separation effect; large amount of chemical reagents used, which can easily cause secondary pollution; long process flow, high separation cost, and difficult operation.

[0005] Chinese invention patent CN110922015B discloses a method and system for the harmless treatment of fluid oily sludge. It uses multiple methods such as air flotation oil removal, centrifugal separation, and high-temperature pyrolysis to treat fluid oily sludge and reduce the oil content in the solid phase. However, the air flotation method is only suitable for low-viscosity oily sludge, and the pyrolysis equipment is expensive, difficult to operate, and prone to air pollution, so it is difficult to apply in practice.

[0006] Chinese utility model patent CN213924380U discloses an oilfield water-oil-sludge separation system. This utility model adds a reagent to the oilfield sludge, heats it with an electric heating system, and then stirs it through a demulsification sedimentation separation tank to separate the oil, water, and solids into layers. However, the separation efficiency of the sedimentation separation method is not high, and the reagent requirement for this process is relatively large. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to provide a highly efficient separation system and method for the three-phase components of oily sludge. The system employs a multi-stage enhanced demulsification method to destabilize the oily sludge. Through homogenization and conditioning pretreatment, coupled with chemically enhanced demulsification and a high-frequency turbulent collision method using multi-layer porous baffles, the oil-water interfacial tension in the oily sludge system is reduced, the aggregation and growth of solid particles are enhanced, and the stable emulsion state of the oily sludge is disrupted, resulting in deep destabilization of the oily sludge. Then, through solid-liquid separation and oil-water separation, the highly efficient separation of the three-phase components of the oily sludge is achieved.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A high-efficiency separation system for three-phase components of oily sludge, comprising:

[0010] Homogenization and conditioning tank 1: used for diluting and reducing the viscosity of oily sludge; the oily sludge inlet of the homogenization and conditioning tank 1 is connected to the oily sludge outlet of the oily sludge storage tank 7, and the water inlet of the homogenization and conditioning tank 1 is connected to the water outlet of the wastewater heating tank 5.

[0011] Demulsification unit 2: used for chemical demulsification and thermal vibration agglomeration demulsification of oily sludge; the oily sludge inlet of the demulsification unit 2 is connected to the oily sludge outlet of the homogenization and conditioning tank 1;

[0012] Separation unit 3: used for three-phase separation of oily sludge after demulsification; the oily sludge inlet of separation unit 3 is connected to the oily sludge outlet of demulsification unit 2;

[0013] Recovery unit 4: used to recover oil, wastewater and oil sludge; the inlets of the oil phase, water phase and oil sludge solid phase of the recovery unit 4 are respectively connected to the outlets of the oil phase, water phase and oil sludge solid phase of the separation unit 3.

[0014] The homogenization and conditioning tank 1 is equipped with an extractor 101. The inlet of the extractor 101 is connected to the outlet of the wastewater heating tank 5. The oily sludge inlet of the extractor 101 is connected to the oily sludge outlet of the oily sludge storage tank 7. The top of the homogenization and conditioning tank 1 is equipped with an oily sludge return inlet connected to the oily sludge outlet of the homogenization and conditioning tank 1.

[0015] The demulsification unit 2 includes an enhanced homogenizer 21 connected to the oily sludge outlet of the homogenizing and conditioning tank 1. The reagent inlet of the enhanced homogenizer 21 is connected to the reagent outlet of the reagent tank 9. The oily sludge outlet of the enhanced homogenizer 21 is connected to the oily sludge inlet of the jet mixer 22. The steam inlet of the jet mixer 22 is connected to the steam outlet of the wastewater heating tank 5 through the steam drum 6. The oily sludge outlet of the jet mixer 22 is connected to the oily sludge inlet of the vibrating flow agglomerator 23.

[0016] The enhanced homogenizer 21 includes a first outer shell 218 and a motor 211 disposed on the top of the first outer shell 218. The power output shaft of the motor 211 is connected to a rotating shaft 212 extending into the first outer shell 218. The other end of the rotating shaft 212 is connected to a rotating cavity 216 disposed within the first outer shell 218. The rotating cavity 216 is provided with packing material 217 and oily sludge pipes 213 and chemical pipes 214 arranged side by side inside the packing material 217. The packing material 217 has a mesh, spherical, annular, or irregular porous structure, and the specific surface area of ​​the packing material 217 is 120-800 m². 2 / m 3 The oily sludge pipe 213 and the chemical pipe 214 are uniformly provided with a number of nozzles 215 facing the packing material 217.

[0017] The oscillating flow agglomerator 23 includes a second outer shell 231, within which 6-10 layers of porous partitions 232 are uniformly arranged, with a layer spacing of 150-300 mm. The porous partitions 232 are machined with a plurality of openings 233, each opening 233 including a contraction section 234, a throat diameter 235, and an expansion section 236. The angle α of the contraction section 234 is 25-35°, and the angle β of the expansion section 236 is 45-65°.

[0018] The separation unit 3 includes a solid-liquid separator 31 connected to the oily sludge outlet of the vibrating flow agglomerator 23 via a transfer pump. The oil-water outlet of the solid-liquid separator 31 is connected to the oil-water inlet of the oil-water separator 32. The low oil-water phase outlet of the oil-water separator 32 is connected to the low oil-water phase inlet of the wastewater degreasing tank 33. A bubble generator 331 is installed at the bottom of the wastewater degreasing tank 33. The gas inlet of the bubble generator 331 is connected to the gas outlet of the gas storage tank 8. During system operation, the oily flotation liquid and part of the wastewater outlet of the wastewater degreasing tank 33 are connected to the inlet of the wastewater heating tank 5. When the system is initially running, the inlet of the wastewater heating tank 5 is connected to the outlet of the water storage tank 10.

[0019] The recycling unit 4 includes a waste residue storage tank 41 connected to the sludge solid phase outlet of the solid-liquid separator 31, an oil storage tank 42 connected to the oil phase outlet of the oil-water separator 32, and a wastewater storage tank 43 connected to the water phase outlet of the wastewater deoiling tank 33.

[0020] A highly efficient method for separating three-phase components of oily sludge, using the aforementioned highly efficient separation system for oily sludge, includes the following steps:

[0021] Step 1: Homogenize and condition the oily sludge;

[0022] The oily sludge and hot water are transported to the homogenization and conditioning tank 1 for extraction and mixing for 15-25 minutes. The oily sludge that was previously extracted and mixed is then returned to the homogenization and conditioning tank 1 for further circulation and mixing to obtain homogenized oily sludge.

[0023] Step 2: The homogenized oily sludge from Step 1 is transported to Demulsification Unit 2 for two-step demulsification treatment using chemical agents and thermal vibration agglomeration.

[0024] The homogenized oily sludge from step 1 is transported to the enhanced homogenizer 21 in the demulsification unit 2 for rotary centrifugal mixing for 3-5 minutes, and then transported to the jet mixer 22 for mixing and dispersion with the hot medium. The temperature of the oily sludge after mixing is 65-85℃. Then it is transported to the vibrating agglomerator 23 for thermal vibration agglomeration and demulsification for 15-30 minutes to obtain the demulsified oily sludge.

[0025] Step 3: The oily sludge after demulsification in Step 2 is transported to the solid-liquid separator 31 of the separation unit 3 for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is transported to the oil-water separator 32 of the separation unit 3 for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is transported to the wastewater deoiling tank 33 for secondary oil-water separation under the action of gas to obtain oily flotation and wastewater;

[0026] Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer 22 in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank 1 in Step 1.

[0027] The homogenized oily sludge in step 1 has a temperature of 40-60℃, a solid content of 10-30%, and a viscosity of ≤1500mPa·s.

[0028] In step 2, the mixed addition amount of demulsifier, flocculant, and pH adjuster is 0.3-1.0% of the homogenized oily sludge; by mass ratio, demulsifier: flocculant: pH adjuster = (5-7): (3-6): (1-2); the pH of the demulsification environment is 7.5-9.0; the heat medium is water vapor at 110-130℃, and the flow rate of the heat medium is 15-25% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is ≤1000mPa·s.

[0029] The demulsifier in step 2 is one or a combination of polyethylene oxide-propylene oxide ether, polyoxyethylene polyoxypropylene octadecyl alcohol ether, polyoxyethylene polyoxypropylene polyether, and nonylphenol polyoxyethylene ether; the flocculant is one or a combination of polyferric chloride, polyferric sulfate, polyaluminum silicate chloride, polyaluminum silicate, and polyacrylamide; the pH adjuster is one or a combination of sodium hydroxide, triethanolamine, citric acid, and hydrochloric acid; and the gas in step 3 is nitrogen, carbon dioxide, or air.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. This invention employs a multi-stage enhanced demulsification method to demulsify oily sludge. Specifically, it uses a centrifugal membrane-forming method coupled with a multi-layer porous baffle high-frequency turbulent collision method of a homogenizer. This not only significantly reduces the oil-water interfacial tension in the oily sludge system but also causes the difficult-to-treat solid particles in the system to agglomerate, thus achieving thorough destabilization of the oil, water, and solid phases. Compared with traditional physical-chemical viscosity-reducing demulsification methods, this method achieves a higher degree of demulsification and better separation of the three phases of oily sludge.

[0032] 2. By setting up an enhanced homogenizer, the present invention achieves efficient mixing of oily sludge and chemicals within the rotating cavity of the enhanced homogenizer. Compared with the traditional mixing method of stirring shaft, the interaction between oily sludge and chemicals is more complete and efficient, the demulsification effect is more significant, and the consumption of chemicals is greatly reduced, thus lowering the treatment cost.

[0033] 3. This invention, by setting up a vortex agglomerator, achieves multi-layer oscillation and multiple agglomeration of oily sludge through the multi-layer porous baffle structure of the vortex agglomerator, which completely solves the technical problem of difficult treatment and separation of solid particles that is common in the demulsification process of oily sludge, and improves the separation effect of oil, water and solid phases.

[0034] 4. This invention transports the heat medium together with the pre-demulsified oily sludge into the vibrating flow agglomerator, where the heat medium and the oily sludge exchange heat directly, accelerating molecular motion and reducing the risk of porous baffle blockage.

[0035] 5. By setting up a solid-liquid separator and an oil-water separator, the present invention sequentially performs solid-liquid separation and oil-water separation on oily sludge, effectively separating the three phases of oil, water and solid, overcoming the defect that a single device cannot achieve comprehensive separation, and significantly improving the separation effect.

[0036] 6. This invention recycles the separated wastewater by setting up a wastewater heating tank. Part of the separated wastewater is recycled to participate in the homogenization and conditioning treatment of oily sludge, and part is sent as a heat medium to a vibrating flow agglomerator to participate in the thermal vibration agglomeration and demulsification of oily sludge. The reuse of wastewater in the system effectively saves water resources and realizes the resource utilization of wastewater.

[0037] In summary, this invention employs a multi-stage enhanced demulsification method to destabilize oily sludge. Through homogenization and conditioning pretreatment, coupled with chemically enhanced demulsification and a high-frequency turbulent collision mechanism using multi-layer porous baffles, the oil-water interfacial tension in the oily sludge system is reduced, strengthening the aggregation and growth of solid particles and disrupting the stable emulsion state of the oily sludge. This results in deep destabilization of the oily sludge. Following solid-liquid separation and oil-water separation, efficient separation of the three phases of the oily sludge is achieved. The method for separating the three phases of oily sludge is simple, requires minimal equipment space, has low energy consumption, and exhibits excellent separation of oil, water, and solid phases, making it a promising candidate for market application. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a highly efficient separation system for three-phase components of oily sludge.

[0039] Figure 2 This is a schematic diagram of the structure of the homogenizer provided by the present invention.

[0040] Figure 3 This is a schematic diagram of the structure of the oscillating flow nucleator provided by the present invention.

[0041] Figure 4 This is the present invention. Figure 3 Sectional view at point AA.

[0042] Figure 5 This is the present invention. Figure 3 A magnified structural diagram at point B in the middle.

[0043] In the diagram: Homogenizing and conditioning tank 1, extractor 101, demulsifying unit 2, homogenizer 21, motor 211, rotating shaft 212, oily sludge pipe 213, reagent pipe 214, nozzle 215, rotating cavity 216, packing 217, first outer shell 218, jet mixer 22, vibrating flow agglomerator 23, second outer shell 231, porous baffle 232, opening 233, contraction section 234, throat diameter 235, expansion section 236, separation unit 3, solid-liquid separator 31, oil-water separator 32, wastewater deoiling tank 33, bubble generator 331, recovery unit 4, oily sludge waste storage tank 41, oil storage tank 42, wastewater storage tank 43, wastewater heating tank 5, steam drum 6, oily sludge storage tank 7, gas storage tank 8, reagent tank 9, water storage tank 10. Detailed Implementation

[0044] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. In embodiments 1 to 14 of the present invention, the solid content of the oil phase separated from the oily sludge was determined by centrifugation, and the water content was determined by distillation, referring to the standard GB / T 260-2016 "Determination of Water Content in Petroleum Products - Distillation Method"; the oil content of the separated wastewater was determined by infrared spectrophotometry, referring to the standard HJ637-2012 "Determination of Petroleum and Animal and Vegetable Oils in Water Quality - Infrared Spectrophotometry".

[0045] like Figure 1 As shown, a high-efficiency separation system for three-phase components of oily sludge includes:

[0046] The homogenization and conditioning tank 1 is used to dilute and reduce the viscosity of oily sludge. The oily sludge inlet of the homogenization and conditioning tank 1 is connected to the oily sludge outlet of the oily sludge storage tank 7. A transfer pump is installed on the pipeline between the oily sludge storage tank 7 and the homogenization and conditioning tank 1 to transport the oily sludge from the storage tank 7 to the homogenization and conditioning tank 1. The inlet of the homogenization and conditioning tank 1 is connected to the outlet of the wastewater heating tank 5 via the transfer pump. The inlet of the wastewater heating tank 5 is connected to the outlet of an external water storage tank 10. Initially, fresh water is supplied from the external water storage tank 10 to the wastewater heating tank. In tank 5; the oily sludge outlet of the homogenization and conditioning tank 1 is connected to the oily sludge inlet of the demulsification unit 2; the homogenization and conditioning tank 1 is equipped with an extractor 101 for mixing the oily sludge with hot water evenly, the inlet of the extractor 101 is connected to the outlet of the wastewater heating tank 5, and the oily sludge inlet of the extractor 101 is connected to the oily sludge outlet of the oily sludge storage tank 7; the top of the homogenization and conditioning tank 1 is equipped with an oily sludge return inlet connected to the oily sludge outlet of the homogenization and conditioning tank 1, for returning part of the oily sludge to the homogenization and conditioning tank 1 for further enhanced mixing and viscosity reduction;

[0047] Demulsification unit 2 is used for chemical demulsification and thermal vibration agglomeration demulsification treatment of oily sludge. The oily sludge inlet of demulsification unit 2 is connected to the oily sludge outlet of homogenization and conditioning tank 1 via a transfer pump. Demulsification unit 2 includes an enhanced homogenizer 21 connected to the oily sludge outlet of homogenization and conditioning tank 1. A transfer pump is installed on the pipeline between enhanced homogenizer 21 and homogenization and conditioning tank 1 to transport the oily sludge in homogenization and conditioning tank 1 to enhanced homogenizer 21 via the pipeline. The reagent inlet of enhanced homogenizer 21 is connected to the reagent outlet of reagent tank 9. The oily sludge outlet of enhanced homogenizer 21 is connected to the oily sludge inlet of jet mixer 22. The steam inlet of jet mixer 22 is connected to the steam outlet of wastewater heating tank 5 via steam drum 6. The oily sludge outlet of jet mixer 22 is connected to the oily sludge inlet of vibrating agglomerator 23.

[0048] like Figure 2 As shown, the homogenizer 21 includes a first housing 218 and a motor 211 disposed on the top of the first housing 218. The power output shaft of the motor 211 is connected to a rotating shaft 212 extending into the first housing 218. The other end of the rotating shaft 212 is connected to a rotating cavity 216 disposed within the first housing 218. The rotating cavity 216 is provided with packing material 217 and oily sludge pipes 213 and reagent pipes 214 arranged side by side inside the packing material 217. The packing material 217 has a mesh, spherical, annular, or irregular porous structure, and the specific surface area of ​​the packing material 217 is 120-800 m². 2 / m 3 The oily sludge pipe 213 and the chemical pipe 214 are uniformly provided with a number of nozzles 215 facing the packing material 217.

[0049] The jet mixer 22 includes an inlet section, a pressure section, and a jet section. The inlet section is conical and converging, the pressure section is circular and tubular, and the jet section is conical and diffusing. The two ends of the pressure section are connected to the inlet section and the jet section, respectively. Under high-speed flow of the hot medium, the pre-demulsified oily sludge is drawn into the pressure section by the annular negative pressure formed by the high-speed airflow. The hot medium and oily sludge in the pressure zone are ejected at high speed after the pressure is released. The oily sludge and the hot medium are forcibly dispersed and fully mixed and heated.

[0050] like Figure 3 As shown, the oscillating current agglomerator 23 includes a second outer shell 231, within which 6-10 layers of porous partitions 232 are uniformly arranged, with a layer spacing of 150-300 mm; the porous partitions 232 are machined with a plurality of openings 233, such as... Figure 4 As shown, the opening 233 includes a contraction section 234, a throat diameter 235, and an expansion section 236. The angle α of the contraction section 234 is 25-35°, and the angle β of the expansion section 236 is 45-65°. Figure 5 As shown, the oily sludge passes through the contraction section 234, the throat diameter 235 and the expansion section 236 in sequence. After being subjected to high-frequency turbulent collisions through the multi-layer porous baffle 232, the emulsified microparticles aggregate and grow, causing secondary deep instability of the oily sludge and generating an oil-water-sludge three-phase interface.

[0051] The separation unit 3 is used to perform solid-liquid separation on the demulsified oily sludge to obtain oily sludge residue and an oil-water mixture. Then, the separated oil-water mixture is further separated to obtain oil and low-oil-content wastewater. Finally, the low-oil-content wastewater is treated based on the principle of air flotation to obtain an oily flotation solution and wastewater. The oily sludge inlet of the separation unit 3 is connected to the oily sludge outlet of the demulsification unit 2 via a transfer pump. The separation unit 3 includes a solid-liquid separator 31 connected to the oily sludge outlet of the vibrating flow agglomerator 23. A transfer pump is installed on the pipeline between the solid-liquid separator 31 and the vibrating flow agglomerator 23 to transport the demulsified oily sludge to the pipeline. Inside the solid-liquid separator 31; the solid-liquid separator 31 is provided with an oil sludge solid phase outlet, and the oil-water outlet of the solid-liquid separator 31 is connected to the oil-water inlet of the oil-water separator 32; the oil-water separator 32 is provided with an oil phase outlet, and the low oil-water phase outlet of the oil-water separator 32 is connected to the low oil-water phase inlet of the wastewater degreasing tank 33; the wastewater degreasing tank 33 is provided with a water phase outlet, and a bubble generator 331 is provided at the bottom of the interior of the wastewater degreasing tank 33; the gas inlet of the bubble generator 331 is connected to the gas outlet of the gas storage tank 8; during system operation, the oily flotation liquid and part of the wastewater outlet of the wastewater degreasing tank 33 are connected to the inlet of the wastewater heating tank 5;

[0052] The recovery unit 4 is used to recover oil, wastewater and oil sludge. The inlets of the oil phase, water phase and oil sludge solid phase of the recovery unit 4 are respectively connected to the outlets of the oil phase, water phase and oil sludge solid phase of the separation unit 3. The recovery unit 4 includes a waste residue storage tank 41 connected to the oil sludge solid phase outlet of the solid-liquid separator 31, an oil storage tank 42 connected to the oil phase outlet of the oil-water separator 32 and a wastewater storage tank 43 connected to the water phase outlet of the wastewater deoiling tank 33.

[0053] The solid-liquid separator 31 is used to separate the solid and liquid of the oily sludge after demulsification. The oily sludge is fed into the high-speed rotating solid-liquid separator 31. Under the action of strong centrifugal force, the denser solid particles are deposited on the wall and pushed to the slag discharge port by the blades of the internal spiral feeder and enter the oily sludge waste storage tank 41. The less dense oil-water mixture overflows and is discharged into the solid-liquid separator 31 and overflows through the oil-water outlet of the solid-liquid separator 31.

[0054] The oil-water separator 32 is used to separate oil and water mixtures with low density. Under the strong centrifugal force generated by high-speed rotation, the oil-water mixture is dispersed. The separated oil phase enters the oil storage tank 42, and the remaining low-oil-content wastewater enters the wastewater de-oiling tank 33. The bubble generator 331 of the wastewater de-oiling tank 33 continuously introduces highly dispersed microbubbles from the bottom into the low-oil-content wastewater, causing the oil phase in the wastewater to move upward with the rising bubbles until it reaches the surface of the liquid, thereby further reducing the oil content in the wastewater. The gas in the bubble generator 331 comes from the gas storage tank 8.

[0055] A highly efficient method for separating three-phase components of oily sludge, using the aforementioned highly efficient separation system for oily sludge, includes the following steps:

[0056] Step 1: Homogenize and condition the oily sludge;

[0057] Oily sludge and hot water are transported to homogenization and conditioning tank 1 for extraction and mixing for 15-25 minutes. The previously extracted and mixed oily sludge is then returned to homogenization and conditioning tank 1 for further circulation and mixing to achieve homogenization and viscosity reduction of the oily sludge, resulting in homogenized oily sludge. The homogenized oily sludge has a temperature of 40-60℃, a solid content of 10-30%, and a viscosity ≤1500mPa·s.

[0058] Step 2: The homogenized oily sludge from Step 1 is transported to Demulsification Unit 2 for two-step demulsification treatment using chemical agents and thermal vibration agglomeration.

[0059] The homogenized oily sludge from step 1, along with the demulsifier, flocculant, and pH adjuster, is transported to the enhanced homogenizer 21 in the demulsification unit 2 for rotary centrifugal mixing for 3-5 minutes. Then, it is transported to the jet mixer 22 for mixing and dispersion with the hot medium to further reduce the viscosity of the oily sludge. The temperature of the oily sludge after mixing is 65-85℃. Finally, it is transported to the vibrating agglomerator 23 for thermal vibration agglomeration and demulsification for 15-30 minutes to obtain the demulsified oily sludge.

[0060] The mixed addition amount of the demulsifier, flocculant, and pH adjuster is 0.3-1.0% of the homogenized oily sludge; by mass ratio, the demulsifier:flocculant:pH adjuster = (5-7):(3-6):(1-2); the pH of the demulsification environment is 7.5-9.0; the demulsifier is one or more combinations of polyethylene oxide-propylene oxide ether, polyoxyethylene polyoxypropylene octadecyl alcohol ether, polyoxyethylene polyoxypropylene polyether, and nonylphenol polyoxyethylene ether; the flocculant is one or more combinations of polyferric chloride, polyferric sulfate, polyaluminum silicate chloride, polyaluminum silicate, and polyacrylamide; the pH adjuster is one or more combinations of sodium hydroxide, triethanolamine, citric acid, and hydrochloric acid; the heat medium is water vapor at 110-130℃, and the flow rate of the heat medium is 15-25% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is ≤1000mPa·s.

[0061] Step 3: The oily sludge after demulsification in Step 2 is transported to the solid-liquid separator 31 of the separation unit 3 for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is then transported to the oil-water separator 32 of the separation unit 3 for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is then transported to the wastewater deoiling tank 33 for secondary oil-water separation under the action of gas to obtain oily flotation and wastewater; the gas is nitrogen, carbon dioxide, or air;

[0062] Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer 22 in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank 1 in Step 1.

[0063] Example 1

[0064] This embodiment selects oily sludge produced by an oilfield. The oily sludge has an oil content of about 50.8%, a water content of about 23.5%, and a slag content of about 25.7%.

[0065] A highly efficient method for separating three-phase components of oily sludge, using the aforementioned highly efficient separation system for oily sludge, includes the following steps:

[0066] Step 1: Homogenize and condition the oily sludge;

[0067] Oily sludge and hot water are transported to homogenization and conditioning tank 1 for pumping and mixing for 15 minutes. The oily sludge that was pumped and mixed previously is then returned to homogenization and conditioning tank 1 for further circulation and mixing to achieve homogenization and viscosity reduction of the oily sludge, resulting in homogenized oily sludge. The homogenized oily sludge has a temperature of 40°C, a solid content of 30%, and a viscosity of 1250 mPa·s.

[0068] Step 2: The homogenized oily sludge from Step 1 is transported to Demulsification Unit 2 for two-step demulsification treatment using chemical agents and thermal vibration agglomeration.

[0069] The homogenized oily sludge from step 1, along with the demulsifier, flocculant, and pH adjuster, is transported to the enhanced homogenizer 21 in the demulsification unit 2 for rotary centrifugal mixing for 3 minutes. Then, it is transported to the jet mixer 22 for mixing and dispersion with the hot medium to further reduce the viscosity of the oily sludge. The temperature of the oily sludge after mixing is 70°C. Finally, it is transported to the vibrating agglomerator 23 for thermal vibration agglomeration and demulsification for 30 minutes to obtain the demulsified oily sludge.

[0070] The mixed addition amount of the demulsifier, flocculant, and pH adjuster is 0.7% of the homogenized oily sludge; the demulsifier:flocculator:pH adjuster ratio is 5:4:1 by mass; the pH of the demulsification environment is 8.5; the demulsifier is polyoxyethylene polyoxypropylene polyether; the flocculant is polysilicon aluminum iron; the pH adjuster is sodium hydroxide and triethanolamine, with a mass ratio of sodium hydroxide:triethanolamine = 2:1; the heat medium is 120°C water vapor, and the flow rate of the heat medium is 20% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is 886 mPa·s;

[0071] Step 3: The oily sludge after demulsification in Step 2 is transported to the solid-liquid separator 31 of the separation unit 3 for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is transported to the oil-water separator 32 of the separation unit 3 for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is transported to the wastewater deoiling tank 33 for secondary oil-water separation under the action of nitrogen to obtain oily flotation and wastewater;

[0072] Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer 22 in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank 1 in Step 1.

[0073] In this embodiment, the packing 217 inside the rotating cavity 216 of the homogenizer 21 is a mesh packing structure with a specific surface area of ​​600 m². 2 / m 3 The oscillating flow agglomerator 23 is uniformly provided with 8 layers of porous partitions 232, and the interlayer spacing of the porous partitions 232 is 220mm; the angle α of the contraction section 234 is 30°, and the angle β of the expansion section 236 is 55°.

[0074] After separation, the solid content and water content in the oil were 0.8% and 38 ppm, respectively, while the oil content in the wastewater was 25 ppm.

[0075] Example 2

[0076] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 1. The difference is that: in step 1, the residence time of the oily sludge in the homogenization and conditioning tank 1 is 25 minutes; the solid content of the homogenized oily sludge is 20%, and the viscosity is 1342 mPa·s; in step 2, the viscosity of the oily sludge after thermal vibration agglomeration and demulsification is 910 mPa·s.

[0077] After separation, the solids content and water content in the oil were 0.9% and 41 ppm, respectively; the oil content in the wastewater was 28 ppm.

[0078] Example 3

[0079] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 2. The difference is that in step 1, the oily sludge and hot water are transported to the homogenization and conditioning tank 1 for extraction and mixing; the temperature of the homogenized oily sludge is 60°C, the solid content is 10%, and the viscosity is 1089 mPa·s; in step 2, the viscosity of the oily sludge after thermal vibration agglomeration and demulsification is 697 mPa·s.

[0080] After separation, the solids content and water content in the oil were 0.6% and 28 ppm, respectively; the oil content in the wastewater was 24 ppm.

[0081] Example 4

[0082] This embodiment selects oily sludge produced by an oilfield. The oily sludge has an oil content of about 25.8%, a water content of about 39.4%, and a slag content of about 34.8%.

[0083] A highly efficient method for separating three-phase components of oily sludge, using the aforementioned highly efficient separation system for oily sludge, includes the following steps:

[0084] Step 1: Homogenize and condition the oily sludge;

[0085] Oily sludge and hot water are transported to homogenization and conditioning tank 1 for pumping and mixing for 20 minutes. The previously pumped and mixed oily sludge is then returned to homogenization and conditioning tank 1 for further circulation and mixing to achieve homogenization and viscosity reduction of the oily sludge, resulting in homogenized oily sludge. The homogenized oily sludge has a temperature of 50°C, a solid content of 20%, and a viscosity of 1187 mPa·s.

[0086] Step 2: The homogenized oily sludge from Step 1 is transported to Demulsification Unit 2 for two-step demulsification treatment using chemical agents and thermal vibration agglomeration.

[0087] The homogenized oily sludge from step 1, along with the demulsifier, flocculant, and pH adjuster, is transported to the enhanced homogenizer 21 in the demulsification unit 2 for rotary centrifugal mixing for 5 minutes. Then, it is transported to the jet mixer 22 for mixing and dispersion with the hot medium to further reduce the viscosity of the oily sludge. The temperature of the oily sludge after mixing is 70°C. Finally, it is transported to the vibrating agglomerator 23 for thermal vibration agglomeration and demulsification for 20 minutes to obtain the demulsified oily sludge.

[0088] The combined addition amount of the demulsifier, flocculant, and pH adjuster is 1.0% of the homogenized oily sludge; the demulsifier:flocculator:pH adjuster ratio is 5:6:2 by mass; the pH of the demulsification environment is 9.0; the demulsifier is nonylphenol polyoxyethylene ether; the flocculant is polyferric sulfate and polyaluminum chloride, with a mass ratio of polyferric sulfate:polyaluminum chloride = 3:2; the pH adjuster is sodium hydroxide; the heat medium is 120°C steam, and the flow rate of the heat medium is 20% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is 687 mPa·s;

[0089] Step 3: The oily sludge after demulsification in Step 2 is transported to the solid-liquid separator 31 of the separation unit 3 for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is transported to the oil-water separator 32 of the separation unit 3 for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is transported to the wastewater deoiling tank 33 for secondary oil-water separation under the action of air to obtain oily flotation and wastewater;

[0090] Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer 22 in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank 1 in Step 1.

[0091] In this embodiment, the packing 217 inside the rotating cavity 216 of the homogenizer 21 is a spherical packing structure with a specific surface area of ​​600 m². 2 / m 3 The oscillating flow agglomerator 23 is uniformly provided with 8 layers of porous partitions 232, and the interlayer spacing of the porous partitions 232 is 220mm; the angle α of the contraction section 234 is 30°, and the angle β of the expansion section 236 is 55°.

[0092] After separation, the solid content and water content in the oil were 0.6% and 32 ppm, respectively, while the oil content in the wastewater was 41 ppm.

[0093] Example 5

[0094] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 4. The difference lies in the following: in step 2, the mixed addition amount of demulsifier, flocculant, and pH adjuster in the homogenizer 21 is 0.3% of the homogenized oily sludge; the packing 217 in the rotating cavity 216 of the homogenizer 21 uses a ring structure with a specific surface area of ​​300 m². 2 / m 3 The viscosity of the oily sludge after thermal agglomeration and demulsification in step 2 is 721 mPa·s.

[0095] After separation, the solid content and water content in the oil were 0.7% and 36 ppm, respectively, while the oil content in the wastewater was 43 ppm.

[0096] Example 6

[0097] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 4. The difference is that the packing material 217 in the rotating cavity 216 of the homogenizer 21 in step 2 is a spherical packing structure with a specific surface area of ​​800 m². 2 / m 3 The viscosity of the oily sludge after thermal agglomeration and demulsification in step 3 is 518 mPa·s.

[0098] After separation, the solid content and water content in the oil were 0.5% and 26 ppm, respectively, while the oil content in the wastewater was 33 ppm.

[0099] Example 7

[0100] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 4. The difference is that the packing material 217 in the rotating cavity 216 of the homogenizer 21 in step 2 has an irregular pore structure and a specific surface area of ​​120 m². 2 / m 3 The viscosity of the oily sludge after thermal agglomeration and demulsification in step 2 is 702 mPa·s.

[0101] After separation, the solid content and water content in the oil were 0.7% and 32 ppm, respectively, while the oil content in the wastewater was 37 ppm.

[0102] Example 8

[0103] This embodiment selects oily sludge produced by an oilfield. The oily sludge has an oil content of about 41.8%, a water content of about 30.8%, and a slag content of about 27.4%.

[0104] A highly efficient method for separating three-phase components of oily sludge, using the aforementioned highly efficient separation system for oily sludge, includes the following steps:

[0105] Step 1: Homogenize and condition the oily sludge;

[0106] Oily sludge and hot water are transported to homogenization and conditioning tank 1 for pumping and mixing for 20 minutes. The previously pumped and mixed oily sludge is then returned to homogenization and conditioning tank 1 for further circulation and mixing to achieve homogenization and viscosity reduction of the oily sludge, resulting in homogenized oily sludge. The homogenized oily sludge has a temperature of 50°C, a solid content of 20%, and a viscosity of 1074 mPa·s.

[0107] Step 2: The homogenized oily sludge from Step 1 is transported to Demulsification Unit 2 for two-step demulsification treatment using chemical agents and thermal vibration agglomeration.

[0108] The homogenized oily sludge from step 1, along with demulsifier, flocculant, and pH adjuster, is transported to the enhanced homogenizer 21 in the demulsification unit 2 for rotary centrifugal mixing for 5 minutes. It is then transported to the jet mixer 22 for mixing and dispersion with a hot medium to further reduce the viscosity of the oily sludge. The temperature of the oily sludge after mixing is 85°C. It is then transported to the vibrating agglomerator 23 for thermal vibration agglomeration and demulsification for 15 minutes to obtain the demulsified oily sludge.

[0109] The mixed addition amount of the demulsifier, flocculant, and pH adjuster is 0.7% of the homogenized oily sludge; the demulsifier:flocculator:pH adjuster ratio is 7:3:1 by mass; the pH of the demulsification environment is 7.5; the demulsifier is polyethylene oxide-propylene oxide ether and polyoxyethylene polyoxypropylene octadecyl alcohol ether, with a mass ratio of polyethylene oxide-propylene oxide ether:polyoxyethylene polyoxypropylene octadecyl alcohol ether = 2:1; the flocculant is polyferric chloride; the pH adjuster is citric acid and hydrochloric acid, with a mass ratio of citric acid:hydrochloric acid = 1:1; the heat medium is 130°C water vapor, and the flow rate of the heat medium is 15% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is 653 mPa·s;

[0110] Step 3: The oily sludge after demulsification in Step 2 is transported to the solid-liquid separator 31 of the separation unit 3 for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is transported to the oil-water separator 32 of the separation unit 3 for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is transported to the wastewater deoiling tank 33 for secondary oil-water separation under the action of carbon dioxide to obtain oily flotation and wastewater;

[0111] Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer 22 in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank 1 in Step 1.

[0112] In this embodiment, the packing 217 inside the rotating cavity 216 of the homogenizer 21 is a mesh packing structure with a specific surface area of ​​600 m². 2 / m 3 The oscillating flow agglomerator 23 is uniformly provided with 8 layers of porous partitions 232, and the interlayer spacing of the porous partitions 232 is 220mm; the angle α of the contraction section 234 is 30°, and the angle β of the expansion section 236 is 55°.

[0113] After separation, the solid content and water content in the oil were 0.8% and 26 ppm, respectively, while the oil content in the wastewater was 30 ppm.

[0114] Example 9

[0115] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 8. The difference is that in step 2, the oily sludge is transported to the jet mixer 22 and mixed and dispersed with water vapor at 110°C. The temperature of the oily sludge after mixing is 65°C. The viscosity of the oily sludge after thermal vibration agglomeration and demulsification in step 2 is 786 mPa·s.

[0116] After separation, the solid content and water content in the oil were 0.9% and 34 ppm, respectively, while the oil content in the wastewater was 39 ppm.

[0117] Example 10

[0118] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 8. The difference is that the flow rate of water vapor entering the jet mixer 22 in step 2 is 25% of the flow rate of the oily sludge after demulsification; and the viscosity of the oily sludge after thermal vibration agglomeration demulsification in step 2 is 599 mPa·s.

[0119] After separation, the solid content and water content in the oil were 0.6% and 23 ppm, respectively, while the oil content in the wastewater was 27 ppm.

[0120] Example 11

[0121] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in embodiment 8. The difference is that in step 2, the vibrating flow agglomerator 23 is uniformly provided with 6 layers of porous baffles 232, and the layer spacing of the porous baffles 232 is 150mm.

[0122] After separation, the solid content and water content in the oil were 0.9% and 35 ppm, respectively, while the oil content in the wastewater was 38 ppm.

[0123] Example 12

[0124] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in embodiment 8. The difference is that in step 2, the vibrating flow agglomerator 23 is uniformly provided with 10 layers of porous baffles 232, and the layer spacing of the porous baffles 232 is 300mm.

[0125] After separation, the solid content and water content in the oil were 0.7% and 23 ppm, respectively, while the oil content in the wastewater was 26 ppm.

[0126] Example 13

[0127] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 8. The difference is that in step 2, the angle α of the contraction section 234 of the opening 233 of the vibrating flow agglomerator 23 is 25°, and the angle β of the expansion section 236 is 45°.

[0128] After separation, the solid content and water content in the oil were 0.9% and 37 ppm, respectively, while the oil content in the wastewater was 42 ppm.

[0129] Example 14

[0130] The process, parameters, and properties of the oily sludge used in this embodiment are the same as those in Embodiment 8. The difference is that in step 2, the angle α of the contraction section 234 of the opening 233 of the vibrating flow agglomerator 23 is 35°, and the angle β of the expansion section 236 is 65°.

[0131] After separation, the solid content and water content in the oil were 0.7% and 24 ppm, respectively, while the oil content in the wastewater was 26 ppm.

[0132] In summary, this invention targets oily sludge of different properties. The results after separation show that the solid content of the oil is ≤1%, the water content of the oil is ≤50ppm, and the oil content in the wastewater is ≤50ppm, demonstrating a good separation effect. The method of this invention for separating and recovering oily sludge can bring significant economic, environmental, and social benefits.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A high efficiency separation system of three phase components of oil containing sludge characterized in that, include: Homogenization and conditioning tank (1): used to dilute and reduce the viscosity of oily sludge; the oily sludge inlet of the homogenization and conditioning tank (1) is connected to the oily sludge outlet of the oily sludge storage tank (7), and the water inlet of the homogenization and conditioning tank (1) is connected to the water outlet of the wastewater heating tank (5). Demulsification unit (2): used for chemical demulsification and thermal vibration agglomeration demulsification of oily sludge; the oily sludge inlet of the demulsification unit (2) is connected to the oily sludge outlet of the homogenizing and conditioning tank (1); the demulsification unit (2) includes an enhanced homogenizer (21) connected to the oily sludge outlet of the homogenizing and conditioning tank (1), the reagent inlet of the enhanced homogenizer (21) is connected to the reagent outlet of the reagent tank (9), the oily sludge outlet of the enhanced homogenizer (21) is connected to the oily sludge inlet of the jet mixer (22), the steam inlet of the jet mixer (22) is connected to the steam outlet of the wastewater heating tank (5) through the steam drum (6), and the oily sludge outlet of the jet mixer (22) is connected to the oily sludge inlet of the vibrating agglomerator (23); The oscillating current agglomerator (23) includes a second outer shell (231), inside which 6-10 layers of porous partitions (232) are uniformly arranged, with a layer spacing of 150-300 mm; the porous partitions (232) are processed with a plurality of openings (233), each opening (233) including a contraction section (234), a throat diameter (235), and an expansion section (236), wherein the angle of the contraction section (234) is... The angle of the expansion segment (236) is 25-35°. The angle is 45-65°. Separation unit (3): used for three-phase separation of oily sludge after demulsification; the oily sludge inlet of the separation unit (3) is connected to the oily sludge outlet of the demulsification unit (2); Recovery unit (4): used to recover oil, wastewater and oil sludge; the inlets of the oil phase, water phase and oil sludge solid phase of the recovery unit (4) are respectively connected to the outlets of the oil phase, water phase and oil sludge solid phase of the separation unit (3).

2. The efficient separation system of three phases of oily sludge according to claim 1, characterized in that: The homogenization and conditioning tank (1) is equipped with an extractor (101). The inlet of the extractor (101) is connected to the outlet of the wastewater heating tank (5). The oily sludge inlet of the extractor (101) is connected to the oily sludge outlet of the oily sludge storage tank (7). The top of the homogenization and conditioning tank (1) is equipped with an oily sludge return inlet connected to the oily sludge outlet of the homogenization and conditioning tank (1).

3. The system for efficient separation of three phases of oily sludge as claimed in claim 1 wherein: The homogenizer (21) includes a first housing (218) and a motor (211) disposed on the top of the first housing (218). The power output shaft of the motor (211) is connected to a rotating shaft (212) extending into the first housing (218). The other end of the rotating shaft (212) is connected to a rotating cavity (216) disposed in the first housing (218). The rotating cavity (216) is provided with packing material (217) and oily sludge pipes (213) and reagent pipes (214) arranged in parallel inside the packing material (217). The packing material (217) is mesh-like, spherical, annular, or has an irregular pore structure. The specific surface area of ​​the packing material (217) is 120-800 m². 2 / m 3 The oily sludge pipe (213) and the chemical pipe (214) are uniformly provided with a number of nozzles (215) facing the packing material (217).

4. The system for efficient separation of three phases of oily sludge as claimed in claim 1 wherein: The separation unit (3) includes a solid-liquid separator (31) connected to the oily sludge outlet of the vibrating flow agglomerator (23). The oil-water outlet of the solid-liquid separator (31) is connected to the oil-water inlet of the oil-water separator (32). The low oil-water phase outlet of the oil-water separator (32) is connected to the low oil-water phase inlet of the wastewater degreasing tank (33). A bubble generator (331) is installed at the bottom of the wastewater degreasing tank (33). The gas inlet of the bubble generator (331) is connected to the gas outlet of the gas storage tank (8). During system operation, the oily flotation liquid and part of the wastewater outlet of the wastewater degreasing tank (33) are connected to the inlet of the wastewater heating tank (5). When the system is initially running, the inlet of the wastewater heating tank (5) is connected to the outlet of the water storage tank (10).

5. The efficient separation system of three phases of oily sludge according to claim 1, characterized in that: The recycling unit (4) includes a waste residue storage tank (41) connected to the sludge solid phase outlet of the solid-liquid separator (31), an oil storage tank (42) connected to the oil phase outlet of the oil-water separator (32), and a wastewater storage tank (43) connected to the water phase outlet of the wastewater deoiling tank (33).

6. A method for efficient separation of three-phase components of oily sludge, characterized in that the separation is carried out using the system for efficient separation of three-phase components of oily sludge according to any one of claims 1 to 5. Includes the following steps: Step 1: Homogenize and condition the oily sludge; The oily sludge and hot water are transported to the homogenization and conditioning tank (1) for 15-25 minutes for extraction and mixing. The oily sludge after the previous extraction and mixing is then returned to the homogenization and conditioning tank (1) for circulation and mixing to obtain homogenized oily sludge. Step 2: The homogenized oily sludge from Step 1 is transported to the demulsification unit (2) for two-step demulsification treatment using chemical agents and thermal vibration agglomeration. The oily sludge homogenized in step 1 is transported to the enhanced homogenizer (21) in the demulsification unit (2) for rotary centrifugal mixing for 3-5 minutes, and then transported to the jet mixer (22) for mixing and dispersion with the hot medium. The temperature of the oily sludge after mixing is 65-85℃. Then it is transported to the vibrating flow agglomerator (23) for thermal vibration agglomeration and demulsification for 15-30 minutes to obtain the demulsified oily sludge. Step 3: The oily sludge after demulsification in step 2 is transported to the solid-liquid separator (31) of the separation unit (3) for solid-liquid separation to obtain oily sludge residue and oil-water mixture; the oil-water mixture is transported to the oil-water separator (32) of the separation unit (3) for primary oil-water separation to obtain oil and low-oil-content wastewater; the low-oil-content wastewater is transported to the wastewater deoiling tank (33) for secondary oil-water separation under the action of gas to obtain oily flotation and wastewater; Step 4: Heat the oily flotation liquid and part of the wastewater in Step 3 into steam and hot water. The steam is sent into the jet mixer (22) in Step 2 as a heat medium, and the hot water is sent into the homogenization and conditioning tank (1) in Step 1.

7. The method of claim 6, wherein the method is characterized by: The homogenized oily sludge in step 1 has a temperature of 40-60℃, a solid content of 10-30%, and a viscosity of ≤1500mPa·s. In step 2, the mixed addition amount of demulsifier, flocculant, and pH adjuster is 0.3-1.0% of the homogenized oily sludge; by mass ratio, demulsifier: flocculant: pH adjuster = (5-7): (3-6): (1-2); the pH of the demulsification environment is 7.5-9.0; the heat medium is water vapor at 110-130℃, and the flow rate of the heat medium is 15-25% of the flow rate of the oily sludge after demulsification; the viscosity of the oily sludge after thermal vibration agglomeration demulsification is ≤1000mPa·s.

8. The method of claim 6, wherein the method is characterized by: The demulsifier in step 2 is one or more of polyoxyethylene polyoxypropylene octadecyl alcohol ether, polyoxyethylene polyoxypropylene polyether, and nonylphenol polyoxyethylene ether; the flocculant is one or more of polyferric chloride, polyferric sulfate, polyaluminum silicate chloride, polyaluminum silicate, and polyacrylamide; the pH adjuster is one or more of sodium hydroxide, triethanolamine, citric acid, and hydrochloric acid; and the gas in step 3 is nitrogen, carbon dioxide, or air.

Images