An oil-containing sludge treatment device and method

Abstract

This invention relates to the field of oily sludge treatment technology, specifically to an oily sludge treatment device and method. The device includes a sludge pretreatment unit for fluidizing and separating impurities from the oily sludge to obtain fluidized sludge; a water washing and oil removal unit for separating mud and oil from the fluidized sludge to obtain sludge oil, oily sludge, and muddy water; the water washing and oil removal unit includes a water washing separation tank connected to a data acquisition device and a separation control device; a solid-liquid separation unit for separating the muddy water and the oily sludge to obtain wastewater and tailings; and a sludge oil purification unit for purifying the sludge oil, during which wastewater is generated. This invention's oily sludge treatment device achieves precise three-phase separation through the coordinated operation of multiple units. Each unit is integrated within a single workshop and connected via a short-path transport channel, reducing energy consumption during material transport.

Description

Technical Field

[0001] This invention relates to the field of oily sludge treatment technology, specifically to an oily sludge treatment device and method. Background Technology

[0002] Oil extraction, refining, and chemical production processes generate large amounts of oily sludge. This type of sludge has a complex composition, containing large amounts of petroleum-based substances, heavy metals, and harmful organic matter. If not properly treated, it will not only occupy a large amount of land resources but also cause serious pollution to soil, groundwater, and the atmosphere, threatening the ecological environment and human health.

[0003] Currently, the main methods for treating oily sludge include incineration, pyrolysis, solvent extraction, biological treatment, chemical demulsification, and centrifugal separation. However, existing treatment technologies and equipment have many shortcomings:

[0004] Poor separation accuracy: Existing processing equipment is not effective in separating the three phases of oil, water, and sludge. Taking centrifugal separation equipment as an example, after processing by traditional single-stage centrifugal separation equipment, the oil content of the tailings is often as high as 5% or more, and the oil phase cannot be effectively separated. Subsequent processing with multiple devices in series is required, which increases the processing cost and complexity.

[0005] High energy consumption and serious pollution: Some treatment technologies, such as incineration and high-temperature pyrolysis, require a large amount of energy and produce harmful gases such as dioxins and sulfur dioxide during the treatment process, causing secondary pollution; the chemical agents used in chemical demulsification may also have adverse effects on the environment.

[0006] Therefore, it is necessary to design an oily sludge treatment device to improve the above-mentioned problems. Summary of the Invention

[0007] To address the problems of existing technologies, the present invention provides an oily sludge treatment device, comprising:

[0008] The sludge pretreatment unit is used to fluidize and separate impurities from oily sludge to obtain fluidized sludge.

[0009] The water washing and oil removal unit is used to separate the fluidized sludge from the oil to obtain sludge oil, oily sludge, and muddy water. The water washing and oil removal unit includes a water washing separation tank, which is connected to a data acquisition device and a separation control device. The separation control device is also connected to a micro-nano bubble generator and a dosing device.

[0010] An oil skimming structure is installed near the top of the water washing separation tank; the data acquisition device is used to collect the temperature, oil content, and solids content of the fluidized sludge, as well as the liquid level information in the water washing separation tank.

[0011] The separation control device is configured to generate fluidization control commands based on the temperature, oil content, and solids content of the fluidized sludge before water washing and the liquid level information in the water washing separation tank, according to a preset water washing separation temperature. The fluidization control commands include at least: a temperature control command, a water inflow control command, and a scraping action command. Based on the fluidization control commands, water washing is introduced into the water washing separation tank to control the temperature of the separation process and separate the floating oil. After the floating oil is separated, the oil sludge and the mud-water are discharged.

[0012] First temporary storage unit: used to store the sludge, oil sludge and mud water separated by the water washing and degreasing unit respectively;

[0013] A solid-liquid separation unit is used to separate the mud and water and the oil sludge into solid and liquid components to obtain wastewater and tailings.

[0014] The second temporary storage unit is used to store the tailings generated by the solid-liquid separation unit.

[0015] The waste oil purification unit is used to purify the waste oil, and wastewater will be generated during the purification process.

[0016] Wastewater treatment unit for treating the wastewater and recycling it for sludge-oil separation of the oily sludge.

[0017] Furthermore, the device also includes an integrated processing system and an intelligent control system;

[0018] The integrated processing system is set up in a single workshop to achieve "closed-loop operation of the entire process within the workshop";

[0019] The workshop is functionally divided into a raw material storage unit on the left, an intermediate equipment unit, a tailings treatment unit on the right, and auxiliary facilities units surrounding the intermediate equipment unit. Each unit is interconnected by a short-path conveying channel with a maximum conveying path of 20m. The raw material storage unit houses the sludge pretreatment unit, which uses a grab bucket to transport fluidized sludge from the sludge pretreatment unit to the intermediate equipment unit. The intermediate equipment unit is sequentially connected to the water washing and oil removal unit, the solid-liquid separation unit, the sludge and oil purification unit, and the wastewater treatment unit. The sludge, oil, wastewater, and tailings generated by the water washing and oil removal unit and the solid-liquid separation unit are respectively transported through pipelines or conveyors to the sludge and oil purification unit, the wastewater treatment unit, and the tailings treatment unit on the right side.

[0020] The water washing separation tank is also equipped with a stirring device, which controls the fluidization process to ensure that the sludge is mixed evenly.

[0021] The intelligent control system includes a PLC control system and an execution module. The PLC control system generates control commands according to preset logic based on the data collected by the data acquisition device, and controls the execution module to achieve three-phase separation of oil, water and mud, ensuring that the water content of the tailings is ≤38%, the oil content of the tailings is ≤1.8%, the oil content of the sludge is ≥45%, and the oil content of the wastewater is ≤10%. At the same time, the PLC control system is also connected to the water washing and oil removal unit, the sludge purification unit and the wastewater treatment unit to realize data interaction and collaborative control, and establish a historical database to optimize control parameters through machine learning.

[0022] Furthermore, the sludge pretreatment unit consists of a pre-screening unit and a conditioning screening unit;

[0023] The pre-screening unit includes a shredder, a cross screen, and a grid. The shredder is used to process bagged oily sludge. The cross screen is located below the shredder, and its screen surface consists of multiple sets of screen shafts rotating in the same direction, with the screen plates of adjacent screen shafts arranged in a cross pattern. The grid is used for preliminary screening of non-bagged or low-impurity oily sludge. The conditioning and screening unit includes a heating feeding tank and a conditioning feeding tank. Both tanks are equipped with steam coils, and low-pressure steam of 0.2-0.4 MPa is introduced into the steam coils to heat the pretreated oily sludge. Temperature sensors are installed in the heating feeding tank and the conditioning feeding tank. The PLC control system is connected to the temperature sensors and the steam supply device. When the temperature of the pretreated oily sludge in the two tanks is below 15°C, the steam coils are turned on for heating. When the temperature reaches 20°C, the steam coils are turned off.

[0024] Furthermore, the oil skimming structure includes an adjustable angle scraper and a scraper drive motor. The output end of the scraper drive motor is connected to the adjustable angle scraper through a transmission component, controlling the angle adjustment range of the adjustable angle scraper to be between 15° and 45°.

[0025] Furthermore, the solid-liquid separation unit includes a conditioning and feeding tank and a vertical scraper centrifuge;

[0026] The conditioning and feeding tank is equipped with an agitator and a time relay. The agitator rotates at a speed of 50-60 r / min. The outlet of the conditioning and feeding tank is connected to a centrifugal pump via a pipe. The flow rate of the centrifugal pump is 10-15 m³ / h. The outlet of the centrifugal pump is connected to the inlet of the vertical scraper centrifuge.

[0027] The vertical scraper centrifuge includes a drum, a scraper system, and a three-phase outlet. The drum is connected to a drum drive motor via a drive shaft, which provides power to rotate the drum. The drum's base speed is set to 3000 r / min, with a deviation threshold of ±50 r / min. When the oil content of the sludge is <45%, the drum speed is increased; when the oil content of the sludge is >10%, the drum speed is decreased; when the oil content of the sludge is ≥45% and the oil content of the sludge is ≤10%, the drum's base speed is maintained.

[0028] The scraper system includes a scraper and a scraper servo drive motor. The scraper is installed inside the drum, and the scraper servo drive motor is installed on the top of the drum. The output end of the scraper servo drive motor extends into the drum and is connected to the scraper through a connecting rod. The angle between the scraper blade and the inner wall of the drum is 15°-20°. The scraper servo drive motor controls the movement trajectory of the scraper through the connecting rod to efficiently scrape away the mud phase accumulated on the inner wall of the drum.

[0029] The three-phase outlets include an oil phase outlet, a water phase outlet, and a mud phase outlet. The mud phase outlet is located at the center of the bottom of the drum and is used to receive the mud phase material scraped off by the scraper. The oil phase outlet and the water phase outlet are located on the side wall of the drum and are at the same height, which facilitates the separation of light oil phase and heavy water phase according to density difference. The three outlets are connected to the sludge buffer tank, the solid waste tank, and the classified sludge storage tank through pipelines, respectively.

[0030] Furthermore, the data acquisition device includes an electromagnetic flow meter, a temperature sensor, a stirring speed sensor, a drum speed sensor, a liquid level sensor, an oil-water interface meter, an online oil content detector, a water content detector, and a turbidity meter, used to collect processing parameters;

[0031] The temperature sensor is installed in the conditioning and screening unit of the raw material storage unit and in each processing tank of the equipment unit. The electromagnetic flow meter is installed between the outlet of the conditioning feed tank and the centrifugal pump. The stirring speed sensor is installed in the conditioning feed tank. The drum speed sensor is installed at the drum drive motor. The liquid level sensor is installed in each processing tank of the equipment unit. The oil-water interface meter is installed in the area connecting the oil phase outlet and the water phase outlet. The online oil content detector is installed in the oil phase outlet pipe, the water phase outlet pipe and the solid-liquid separation unit outlet, respectively. The water content detector is installed in the solid-liquid separation unit outlet.

[0032] The execution module includes a centrifugal pump frequency converter, a drum drive motor frequency converter, an oil phase outlet electric valve, a water phase outlet electric valve, and a scraper servo drive motor.

[0033] Furthermore, an oil phase electric valve is installed at the oil phase outlet, which is linked to an online oil content detector installed on the oil phase outlet pipeline. The valve opens when the oil content is ≥45% and closes when the oil content is <45%, increasing the drum speed. Similarly, an water phase electric valve is installed at the water phase outlet, linked to an online oil content detector installed on the water phase outlet pipeline. It opens when the oil content is ≤10% and closes when the oil content is >10%, decreasing the drum speed. The scraper servo drive motor is linked to the moisture content detector and oil content detector at the solid-liquid separation unit outlet. When the tailings moisture content is ≤38% and the tailings oil content is ≤1.8%, the scraper starts scraping sludge in the order of upper, middle, and lower layers at 30-second intervals, with a scraping interval of 2 minutes per cycle.

[0034] The PLC control system connects the oil-water interface meter, the online oil content detector, and the oil scraper drive motor. When the oil layer thickness is <10mm and the viscosity is <30mPa·s, the adjustable angle oil scraper rotates 45°; when the oil layer thickness is 10-15mm and the viscosity is 30-50mPa·s, the adjustable angle oil scraper rotates 30°; when the oil layer thickness is ≥15mm or the viscosity is ≥50mPa·s, the adjustable angle oil scraper rotates 15°.

[0035] Furthermore, the separation control device is configured as follows: based on data collected by the data acquisition device, the preset water washing separation reference temperature is 25-30℃. When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is >20% and the solid content is <30%, the heating power of the steam coil is adjusted to the rated power. When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is ≤20% or the solid content is ≥30%, the heating power of the steam coil is adjusted to 60% of the rated power. When the temperature of the fluidized sludge is higher than the preset water washing separation reference temperature, the device switches to constant temperature mode and maintains the heating power of the steam coil at 20% of the rated power. This establishes a three-dimensional coupling model, and generates temperature control commands based on the three-dimensional coupling model.

[0036] Simultaneously, a dynamic flow algorithm is used to generate influent control commands, achieving stepped influent. The dynamic flow algorithm expression is: Q=K×V / T, where Q is the dynamic flow rate, K is the flow coefficient, V is the effective volume of the water washing separation tank, and T is the water washing separation cycle. When the oil layer thickness is less than the minimum oil scraping thickness, the oil scraper angle is adjusted to 45°, and the scraping frequency is set to 1 time / minute. When the oil layer thickness is between the minimum and maximum oil scraping thickness, the oil scraper angle is adjusted to 30°, and the scraping frequency is 2 times / minute. When the oil layer thickness reaches the maximum oil scraping thickness, the oil scraper angle is adjusted to 15°, and the scraping frequency is increased to 3 times / minute, constructing a linkage control logic. Based on this logic, scraping action commands are generated, the command execution timing is optimized, and parameters are corrected through feedback to ensure that the control command execution error is ≤5%. At the same time, the separation control device is linked with the dosing device and the micro-nano bubble generator, and data sharing is achieved with the sludge and oil purification unit and the wastewater treatment unit.

[0037] The water inlet control command is executed first. After the liquid level in the water washing separator reaches the preset value, the temperature control command is activated. When the temperature is stable and the thickness of the floating oil layer is greater than the preset thickness, the scraping action command is executed. The real-time feedback correction logic is as follows: when the temperature deviation is >2℃, the heating power of the steam coil is adjusted; when the floating oil scraping rate is <90%, the oil scraping parameters are corrected; when the water inlet deviation is >10%, a fault alarm is triggered.

[0038] Furthermore, the dosing device adds bio-based agents at a dosage of 0.5%-1.5% of the mass of the oil sludge suspension; the micro-nano bubble generator is linked to the dosing device through an oil-water interface sensor, and after demulsification, the thickness of the floating oil layer is confirmed by the oil-water interface instrument, and the floating oil scraping structure is activated based on the thickness of the floating oil layer.

[0039] A method for treating oily sludge includes the following steps:

[0040] Step 1, Pretreatment: The oily sludge is first processed in the sludge pretreatment unit and then homogenized.

[0041] Step 2, Water washing and oil separation: The homogenized fluidized sludge is pumped into the water washing and oil separation tank of the water washing and oil separation unit. Bio-based agents are added to the water washing and separation tank, stirred and allowed to stand and separate into layers. When the thickness of the floating oil layer is greater than the preset thickness, the floating oil separation operation is performed. The sludge, oil sludge and mud water discharged after floating oil separation are stored in the first temporary storage unit respectively. The separated oil sludge and mud water are transported to the solid-liquid separation unit.

[0042] Step 3, Solid-liquid separation: Under the action of centrifugal force, the mud and water and the oil sludge in the solid-liquid separation unit are separated into solid and liquid, resulting in wastewater and tailings.

[0043] Step 4, Sewage and oil purification: The separated sewage and oil are separated by centrifugation. The speed of the vertical scraper centrifuge is adjusted according to the oil content. Wastewater generated during the purification process is transported to the wastewater treatment unit.

[0044] Step 5, Wastewater Treatment: The wastewater first undergoes pretreatment, and then sequentially undergoes chemical dosing and stirring, coagulation and sedimentation, dissolved air flotation and three-stage filtration. The resulting greywater is recycled for the separation of sludge and oil in oily sludge.

[0045] Step 6, Residue Disposal: The tailings are utilized for resource recovery or treated to render them harmless.

[0046] The beneficial effects of this invention are:

[0047] (1) The oily sludge treatment device of the present invention has high separation accuracy: the oily sludge is fluidized and impurities are separated by the sludge pretreatment unit to improve the material properties; the water washing oil removal unit adopts bio-based agents and micro-nano bubble-assisted demulsification, combined with an adjustable angle oil scraping structure, with an oil scraping rate ≥95% and a water content ≤10%; the solid-liquid separation unit adopts a vertical scraper centrifuge, combined with online detection and linkage control, to ensure that the tailing residue water content ≤38%, the tailing residue oil content ≤1.8%, the sludge oil content ≥45%, and the sewage oil content ≤10%, with a separation accuracy significantly better than the prior art;

[0048] (2) The present invention has low energy consumption and low pollution: each unit is integrated in a single workshop and connected by a short-path conveying channel to reduce the energy consumption of material conveying; bio-based agents are used to replace traditional chemical demulsifiers to avoid secondary pollution of the environment by chemical agents; wastewater is recycled after treatment with a reuse rate of ≥80%, reducing water consumption and wastewater discharge; the intelligent control system achieves precise control to avoid energy waste, and only heating to 15-20℃ in winter reduces energy consumption by more than 30%; the tailings resource utilization rate is ≥90%, realizing harmless and resource utilization and reducing environmental pollution;

[0049] (3) The present invention has high processing efficiency: the water washing and oil removal unit optimizes the control logic and equipment structure, shortening the processing cycle by 20%; the whole process is automatically controlled, reducing manual intervention and improving the overall processing efficiency; the annual processing capacity of a single unit has increased from the traditional 30,000 tons to 36,000 tons, greatly improving the processing capacity;

[0050] (4) The invention has high space utilization: a single unit occupies ≤4500㎡, which saves 25% of space compared with the traditional decentralized layout (≥6000㎡), reducing site construction costs;

[0051] (5) The present invention has a high degree of automation and intelligence: the PLC control system links various data acquisition devices and execution modules to realize real-time parameter monitoring, dynamic adjustment, automatic alarm of abnormality and multi-unit collaborative control, establishes historical database and optimizes parameters through machine learning, improves processing stability by 40%, avoids human operation error and reduces the intensity of manual operation. Attached Figure Description

[0052] Figure 1 : Workshop layout diagram of the oily sludge treatment device of the present invention;

[0053] Figure 2 : Process flow diagram of the oily sludge treatment method of the present invention;

[0054] Figure 3 : A schematic diagram of the structure of the vertical scraper centrifuge of the present invention;

[0055] Figure 4 : A schematic diagram of the water washing separation tank in the equipment unit of this invention;

[0056] Figure 5 : A schematic diagram of the structure of the heating feeding tank and the conditioning feeding tank in the sludge pretreatment unit of this invention;

[0057] Figure 6 : A schematic diagram of the shredder and cross screen in the sludge pretreatment unit of this invention;

[0058] Figure 7 : A schematic diagram of the structure of the bar screen in the sludge pretreatment unit of this invention;

[0059] Attached reference numerals: 1-Raw material storage unit, 2-Equipment unit, 3-Tail residue treatment unit, 4-Mud phase outlet, 5-Oil phase outlet, 6-Water phase outlet, 7-Floating oil scraping structure, 8-Shredder, 9-Cross screen, 10-Grate, 11-Heated feeding tank, 12-Tempering feeding tank, 13-Steam coil, 14-Drum, 15-Scraper system. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Please see Figure 1-7 The present invention provides an oily sludge treatment device, comprising:

[0062] The sludge pretreatment unit is used to fluidize and separate impurities from oily sludge to obtain fluidized sludge.

[0063] The water washing and oil removal unit is used to separate the fluidized sludge from the oil to obtain sludge oil, oily sludge, and muddy water. The water washing and oil removal unit includes a water washing separation tank, which is connected to a data acquisition device and a separation control device. The separation control device is also connected to a micro-nano bubble generator and a dosing device.

[0064] An oil skimming structure is installed near the top of the water washing separation tank; the data acquisition device is used to collect the temperature, oil content, and solids content of the fluidized sludge, as well as the liquid level information in the water washing separation tank.

[0065] The separation control device is configured to generate fluidization control commands based on the temperature, oil content, and solids content of the fluidized sludge before water washing and the liquid level information in the water washing separation tank, according to a preset water washing separation temperature. The fluidization control commands include at least: a temperature control command, a water inflow control command, and a scraping action command. Based on the fluidization control commands, water washing is introduced into the water washing separation tank to control the temperature of the separation process and separate the floating oil. After the floating oil is separated, the oil sludge and the mud-water are discharged.

[0066] First temporary storage unit: used to store the sludge, oil sludge and mud water separated by the water washing and degreasing unit respectively;

[0067] A solid-liquid separation unit is used to separate the mud and water and the oil sludge into solid and liquid components to obtain wastewater and tailings.

[0068] The second temporary storage unit is used to store the tailings generated by the solid-liquid separation unit.

[0069] The waste oil purification unit is used to purify the waste oil, and wastewater will be generated during the purification process.

[0070] Wastewater treatment unit for treating the wastewater and recycling it for sludge-oil separation of the oily sludge.

[0071] Furthermore, the device also includes an integrated processing system and an intelligent control system;

[0072] The integrated processing system is set up in a single workshop to achieve "closed-loop operation of the entire process within the workshop";

[0073] The workshop is functionally divided into a raw material storage unit 1 on the left, an intermediate equipment unit 2, a tailings treatment unit 3 on the right, and auxiliary facilities units arranged around the intermediate equipment unit 2. Each unit is interconnected by a short-path conveying channel with a maximum conveying path of no more than 20m. The raw material storage unit 1 is equipped with the sludge pretreatment unit, and fluidized sludge from the sludge pretreatment unit is conveyed to the intermediate equipment unit 2 via a grab bucket. The intermediate equipment unit 2 is sequentially connected to the water washing and oil removal unit, the solid-liquid separation unit, the sludge purification unit, and the wastewater treatment unit. The sludge, wastewater, and tailings generated by the water washing and oil removal unit and the solid-liquid separation unit are respectively conveyed to the sludge purification unit, the wastewater treatment unit, and the tailings treatment unit 3 on the right side via pipelines or conveyors. The raw material storage unit 1 is used to temporarily store oily sludge to be treated, the equipment unit 2 integrates the water washing and oil removal unit, the solid-liquid separation unit, the sludge purification unit, and the wastewater treatment unit, and the tailings treatment unit 3 is used for the resource-based disposal of tailings.

[0074] The water washing separation tank is also equipped with a stirring device, which controls the fluidization process to ensure that the sludge is mixed evenly.

[0075] The intelligent control system includes a PLC control system and an execution module. The PLC control system can generate control commands according to preset logic based on the data collected by the data acquisition device, and control the action of the execution module to achieve three-phase separation of oil, water and mud, ensuring that the water content of the tailings is ≤38%, the oil content of the tailings is ≤1.8%, the oil content of the sludge is ≥45%, and the oil content of the wastewater is ≤10%. At the same time, the PLC control system is also connected to the water washing and oil removal unit, the sludge purification unit and the wastewater treatment unit to realize data interaction and collaborative control, and establish a historical database to optimize control parameters through machine learning.

[0076] It should be noted that the preset liquid level range of the water washing separator is 40%-60% of the tank volume. When the liquid level is >60%, the overflow valve is opened and the feeding is stopped; when the liquid level is <40%, the outflow rate is reduced and the feed rate is increased. The intelligent control system includes a PLC control system and an execution module. The PLC control system can generate control commands according to a preset logic algorithm based on the real-time data collected by the data acquisition device, including feed flow rate, stirring speed, drum speed, drum liquid level, oil-water interface height, oil content and water content at each outlet. This algorithm processes the input based on predefined rules. The data drives the execution module to perform corresponding actions, efficiently realizing the three-phase separation process of oil, water, and sludge. It strictly ensures that the water washing tailings have a moisture content of ≤38%, an oil content of ≤1.8%, a separated sludge oil content of ≥45%, and a separated wastewater oil content of ≤10%. At the same time, the PLC control system achieves data interaction and collaborative control with the water washing oil removal unit, the sludge oil purification unit, and the wastewater treatment unit, coordinating the operation of each unit to optimize overall performance. It also establishes a historical database to record operating information and analyzes the data through machine learning technology to automatically optimize control parameters, thereby improving system stability and separation efficiency.

[0077] Furthermore, the sludge pretreatment unit consists of a pre-screening unit and a conditioning screening unit; the pre-screening unit includes a shredder 8, a cross screen 9, and a grid 10. The shredder 8 is used to process bagged oily sludge. The cross screen 9 is located below the shredder 8, and its screen surface is composed of multiple sets of screen shafts rotating in the same direction, with the screen plates of adjacent screen shafts arranged in a cross pattern. The grid 10 is used for preliminary screening of non-bagged or low-impurity oily sludge; the conditioning screening unit includes a heated feeding tank 11 and a conditioning feeding tank 12. Both tanks are equipped with steam coils 13, which are connected to the heating tank via "["-shaped fixing blocks. The installation ring connects to the steam coil 13, which is installed on the inner wall of the tank. Low-pressure steam at 0.2-0.4 MPa and 120-150℃ is introduced into the steam coil 13 for 20-30 minutes. The low-pressure steam heats the pretreated oily sludge. Temperature sensors are installed in the heating feeding tank 11 and the conditioning feeding tank 12. The PLC control system is connected to the temperature sensors and the steam supply device. When the temperature of the pretreated oily sludge in the two tanks is below 15℃, the steam coil 13 is turned on to heat. When the temperature reaches 20℃, the steam coil 13 is turned off.

[0078] Furthermore, the oil skimming structure 7 includes an adjustable angle scraper and a scraper drive motor. The output end of the scraper drive motor is connected to the adjustable angle scraper via a spur gear, controlling the angle adjustment range of the adjustable angle scraper to be between 15° and 45°.

[0079] Furthermore, the solid-liquid separation unit includes a conditioning and feeding tank and a vertical scraper centrifuge;

[0080] The conditioning and feeding tank is equipped with an agitator and a time relay. The agitator rotates at a speed of 50-60 r / min. The outlet of the conditioning and feeding tank is connected to a centrifugal pump through a pipeline. The flow rate of the centrifugal pump is 10-15 m³ / h, the pressure difference between the inlet and outlet is 0.3-0.5 MPa, and the medium temperature is controlled at 40-60℃. The outlet of the centrifugal pump is connected to the inlet of the vertical scraper centrifuge.

[0081] The vertical scraper centrifuge includes a drum 14, a scraper system 15, and a three-phase outlet. The drum 14 is connected to a drum drive motor via a drive shaft. The drum drive motor provides power to make the drum 14 rotate at high speed, thereby realizing the centrifugal separation process. The reference speed of the drum 14 is set to 3000 r / min, and the deviation threshold is ±50 r / min. When the oil content of the sludge is <45%, the drum speed is increased; when the oil content of the wastewater is >10%, the drum speed is decreased; when the oil content of the sludge is ≥45% and the oil content of the wastewater is ≤10%, the reference speed of the drum is maintained.

[0082] The scraper system 15 includes a scraper and a scraper servo drive motor. The scraper is installed inside the drum 14, and the scraper servo drive motor is installed on the top of the drum 14. The output end of the scraper servo drive motor extends into the drum 14 and is connected to the scraper through a connecting rod. The angle between the scraper blade and the inner wall of the drum 14 is 15°-20°. The scraper servo drive motor controls the movement trajectory of the scraper through the connecting rod to efficiently scrape away the mud phase accumulated on the inner wall of the drum 14 and ensure a clean separation surface.

[0083] The three-phase outlets include an oil phase outlet, a water phase outlet, and a mud phase outlet. The mud phase outlet is located at the center of the bottom of the drum 14 and is used to receive the mud phase material scraped off by the scraper. The oil phase outlet and the water phase outlet are located on the side wall of the drum 14 and are at the same height, which facilitates the separation of light oil phase and heavy water phase according to density difference. The three outlets are connected to the sludge buffer tank, the solid waste tank, and the classified sludge storage tank through pipelines respectively.

[0084] The three-phase outlets include an oil phase outlet 5, a water phase outlet 6, and a mud phase outlet 4. The mud phase outlet 4 is located at the center of the bottom of the drum 14 and is used to receive the mud phase material scraped off by the scraper. The oil phase outlet 5 and the water phase outlet 6 are located on the side wall of the drum 14 and are at the same height, which facilitates the separation of light oil phase and heavy water phase according to density difference. The three outlets are connected to the sludge buffer tank, the solid waste tank, and the classified sludge storage tank through pipelines, respectively.

[0085] Furthermore, the data acquisition device includes an electromagnetic flow meter, a temperature sensor, a stirring speed sensor, a drum speed sensor, a liquid level sensor, an oil-water interface meter, an online oil content detector, a water content detector, and a turbidity meter, used to collect processing parameters;

[0086] The temperature sensor is installed in the conditioning and screening unit of the raw material storage unit 1 and each processing tank of the equipment unit 2. The electromagnetic flow meter is installed between the outlet of the conditioning feed tank and the centrifugal pump. The stirring speed sensor is installed in the conditioning feed tank. The drum speed sensor is installed at the drum drive motor. The liquid level sensor is installed in each processing tank of the equipment unit 2. The oil-water interface meter is installed in the area connecting the oil phase outlet 5 and the water phase outlet 6. The online oil content detector is installed in the oil phase outlet 5 pipeline, the water phase outlet 6 pipeline and the solid-liquid separation unit outlet, respectively. The water content detector is installed in the solid-liquid separation unit outlet.

[0087] The execution module includes a centrifugal pump frequency converter, a drum drive motor frequency converter, an oil phase outlet electric valve, a water phase outlet electric valve, and a scraper servo drive motor.

[0088] Furthermore, an oil phase electric valve is installed at the oil phase outlet 5. This valve is linked to an online oil content detector installed on the oil phase outlet 5 pipeline. The valve opens when the oil content of the sludge is ≥45% and closes when the oil content is <45%, and the drum speed is increased (from 3000 r / min to 3500 r / min; after adjustment, the oil content is continuously monitored until it reaches ≥45%, at which point the valve reopens). An aqueous phase electric valve is installed at the aqueous phase outlet 6. The water phase electric valve is linked to the online oil content detector installed on the water phase outlet 6 pipe. It opens when the oil content of the wastewater is ≤10% and closes and reduces the drum speed when the oil content of the wastewater is >10%. The scraper servo drive motor is linked to the moisture content detector and oil content detector at the outlet of the solid-liquid separation unit. When the moisture content of the tailings is ≤38% and the oil content of the tailings is ≤1.8%, the scraper starts scraping sludge in the order of upper layer, middle layer and lower layer at 30-second intervals, with a scraping interval of 2 minutes / time.

[0089] The PLC control system connects the oil-water interface meter, the online oil content detector, and the oil scraper drive motor. When the oil layer thickness is <10mm and the viscosity is <30mPa·s, the adjustable angle oil scraper rotates 45°; when the oil layer thickness is 10-15mm and the viscosity is 30-50mPa·s, the adjustable angle oil scraper rotates 30°; when the oil layer thickness is ≥15mm or the viscosity is ≥50mPa·s, the adjustable angle oil scraper rotates 15°.

[0090] It should be noted that the oil-water interface meter in the water washing separator monitors the thickness of the floating oil layer in real time (accuracy ±1mm), and the online oil content meter simultaneously acquires the viscosity data of the floating oil. The data is refreshed every second by the PLC control system. The control system has built-in logic: when the floating oil layer thickness is <10mm and the viscosity is <30mPa·s, a 45° adjustment command is triggered; when the floating oil layer thickness is 10-15mm and the viscosity is 30-50mPa·s, a 30° reference command is executed; when the floating oil layer thickness is ≥15mm or the viscosity is ≥50mPa·s, a 15° adjustment command is initiated.

[0091] The PLC control system sends pulse signals to the scraper servo drive motor, which in turn drives the scraper blade's rotating shaft via a spur gear transmission mechanism. The built-in SCA126T angle sensor provides real-time feedback on the actual angle. When the detected value deviates from the target value by ≤0.5°, the scraper blade drive motor stops, completing the angle lock (response time ≤0.3 seconds). After angle adjustment, the system automatically matches the scraping frequency (15° corresponds to 3 times / minute, 30° to 2 times / minute, and 45° to 1 time / minute). After each scraping cycle, the floating oil moisture content detector provides feedback. If the moisture content is >10%, the system automatically fine-tunes the angle (±5°) and re-executes the scraping until the target is met.

[0092] Furthermore, the separation control device is configured as follows: based on data collected by the data acquisition device, the preset water washing separation reference temperature is 25-30℃. When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is >20% and the solid content is <30%, the heating power of the steam coil is adjusted to the rated power (50kW). When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is ≤20% or the solid content is ≥30%, the heating power of the steam coil is adjusted to 60% of the rated power (30kW). When the temperature of the fluidized sludge is higher than the preset water washing separation reference temperature, the device switches to constant temperature mode and maintains the heating power of the steam coil at 20% of the rated power (10kW). A three-dimensional coupling model is thus established, and temperature control commands are generated based on the three-dimensional coupling model.

[0093] Simultaneously, a dynamic flow rate algorithm is used to generate influent control commands, achieving stepped influent. The dynamic flow rate algorithm expression is: Q=K×V / T, where Q is the dynamic flow rate (m³ / h), K is the flow coefficient (range 1.2-1.5), V is the effective volume of the water washing separation tank (m³), and T is the water washing separation cycle (h). When the oil layer thickness is less than 10mm (minimum oil scraping thickness), the scraper angle is adjusted to 45°, and the scraping frequency is set to 1 time / min. When the oil layer thickness is between 10mm and 15mm... When the oil layer thickness reaches or exceeds 15mm (maximum scraping thickness), the scraper angle is adjusted to 15° and the scraping frequency is increased to 3 times / min, establishing a linkage control logic. Based on this logic, scraping action commands are generated, the command execution timing is optimized, and parameters are corrected through feedback to ensure that the control command execution error is usually ≤5%. At the same time, the separation control device is linked with the dosing device and the micro-nano bubble generator, and data sharing is achieved with the sludge and oil purification unit and the wastewater treatment unit.

[0094] The water inlet control command is executed first. After the liquid level in the water washing separator reaches the preset value, the temperature control command is activated. When the temperature is stable and the thickness of the floating oil layer is greater than the preset thickness, the scraping action command is executed. The real-time feedback correction logic is as follows: when the temperature deviation is >2℃, the heating power of the steam coil is adjusted; when the floating oil scraping rate is <90%, the oil scraping parameters are corrected; when the water inlet deviation is >10%, a fault alarm is triggered.

[0095] Furthermore, the dosing device adds a bio-based agent at a dosage of 0.5%-1.5% of the mass of the oil sludge suspension. The micro / nano bubble generator is linked to the dosing device via an oil-water interface sensor. After demulsification, the thickness of the floating oil layer is confirmed by the oil-water interface instrument, and the floating oil scraping structure 7 is activated based on the thickness of the floating oil layer. The micro / nano bubble generator is model MNB-500, with a bubble diameter of 50-100 μm, a gas flow rate of 1-2 m³ / h, and an operating pressure of 0.3-0.5 MPa. The bio-based agent has application number CN201910571546.5 and is entitled "An Acidic Separation Treatment Agent and Separation Treatment Method for Oil Sludge."

[0096] It should be noted that the dosing device adds bio-based reagents (0.5%-1.5% of the oil sludge suspension mass); the micro-nano bubble generator is linked to the dosing device, and the reagent dosage calculation logic is as follows: the PLC control system sets the dosage (C) based on the oil sludge suspension mass (M=V×ρ, where V is the volume of material in the device and ρ is the density) and the oil content O.

[0097] Oil content O > 20%: C = 1.2%-1.5% (high oil content requires more medication to enhance demulsification);

[0098] 10%≤oil content 0≤20%: C=0.8%-1.2% (conventional dosage);

[0099] Oil content O < 10%: C = 0.5%-0.8% (low oil content requires less pesticide to avoid waste).

[0100] Dosing Start-up: After the material enters the fluidized sludge separator, the PLC control system sends a "start command" to the dosing pump and sets the pump flow rate according to the calculated C value (e.g., if M=15t, C=1%, then the dosage is 0.15t, the pump flow rate is 0.03t / min, and the dosing is completed in 5 minutes). Micro-nano bubble generator linkage: 5 minutes after the dosing starts, the PLC control system sends a "start command" to the micro-nano bubble generator, setting the bubble diameter to 50-200nm (if the oil content O is high, the bubble diameter is reduced to increase the contact area), and the running time is 10-15 minutes. After demulsification, the oil-water interface instrument confirms the formation of the floating oil layer (H≥3mm), and the PLC control system triggers the floating oil scraping logic; otherwise, the running time of the micro-nano bubble generator is extended by 5 minutes.

[0101] A method for treating oily sludge includes the following steps:

[0102] Step 1, Pretreatment: The oily sludge is first processed in the sludge pretreatment unit and then homogenized.

[0103] Step 2, Water washing and oil separation: The homogenized fluidized sludge is pumped into the water washing and oil separation tank of the water washing and oil separation unit. Bio-based agents are added to the water washing and separation tank, stirred and allowed to stand and separate into layers. When the thickness of the floating oil layer is greater than the preset thickness, the floating oil separation operation is performed. The sludge, oil sludge and mud water discharged after floating oil separation are stored in the first temporary storage unit respectively. The separated oil sludge and mud water are transported to the solid-liquid separation unit.

[0104] Step 3, Solid-liquid separation: Under the action of centrifugal force, the mud and water and the oil sludge in the solid-liquid separation unit are separated into solid and liquid, resulting in wastewater and tailings.

[0105] Step 4, Sludge and Oil Purification: The separated sludge and oil are separated by centrifugation. The speed of the vertical scraper centrifuge is adjusted according to the oil content. The purified sludge and oil are recycled. Wastewater generated during the purification process is transported to the wastewater treatment unit.

[0106] Step 5, Wastewater Treatment: The wastewater first undergoes pretreatment, followed by chemical dosing and stirring, coagulation and sedimentation, dissolved air flotation, and three-stage filtration. The treated wastewater can be recycled for the separation of oil and sludge. The floating oil obtained after treatment is returned to the waste oil purification unit for further purification.

[0107] Step 6, Residue Disposal: The tailings are utilized for resource recovery or treated to render them harmless. For example, the washed tailings can be used for brick making or road paving, or the sewage sludge can be thermally desorbed and then mixed with a solidifying agent for disposal.

[0108] In specific implementation, the oily sludge treatment device of the present invention includes a sludge pretreatment unit, a water washing and oil removal unit, a first temporary storage unit, a solid-liquid separation unit, a second temporary storage unit, an oily sludge purification unit, a wastewater treatment unit, an integrated treatment system, and an intelligent control system. Each unit works in concert to achieve efficient treatment and resource recovery of oily sludge.

[0109] The sludge pretreatment unit consists of a pre-screening unit and a conditioning screening unit;

[0110] The sludge pretreatment unit includes a shredder 8, a cross screen 9, and a grid 10. The shredder 8 processes bagged oily sludge by shredding it for easier subsequent processing. The cross screen 9 is located below the shredder 8; its screen surface consists of multiple sets of screen shafts rotating in the same direction, with the screen plates of adjacent shafts arranged in a cross pattern to effectively separate impurities from the shredded oily sludge. The grid 10 performs preliminary screening of non-bagged or low-impurity oily sludge, removing large impurities to ensure smooth subsequent processing.

[0111] The conditioning and screening unit includes a heating feeding tank 11 and a conditioning feeding tank 12. Both tanks are equipped with steam coils 13. Low-pressure steam (0.2-0.4 MPa, 120-150℃) is continuously introduced into the steam coils 13 for 20-30 minutes, heating the pretreated oily sludge. Temperature sensors are installed in both the heating feeding tank 11 and the conditioning feeding tank 12. The PLC control system is connected to the temperature sensors and the steam supply device. When the temperature of the pretreated oily sludge in both tanks is below 15℃, the steam coils 13 are activated for heating; when the temperature reaches 20℃, the steam coils 13 are deactivated. Heating reduces the viscosity of the oily sludge, improves its flowability, and facilitates subsequent fluidization and separation operations.

[0112] The water washing and oil removal unit is used to separate oil from fluidized sludge, yielding sludge, oily sludge, and muddy water. It includes a water washing separation tank, a data acquisition device, a separation control device, an oil skimming structure, a stirring device, a micro / nano bubble generator, and a chemical dosing device.

[0113] The washing separation tank is equipped with an internal stirring device, which controls the fluidization process to ensure thorough mixing of sludge and wash water, thereby improving the separation efficiency. The washing separation tank is connected to a data acquisition device and a separation control device for real-time monitoring and control of the separation process.

[0114] Data acquisition device: Used to collect information on the temperature, oil content, and solids content of fluidized sludge, as well as the liquid level information in the washing separation tank (including liquid level height, oil layer thickness, washing water turbidity, and stirring speed), providing data support for the separation control device to generate control commands. The turbidity of the washing water is collected using a turbidity meter to assess its cleanliness, which is used to optimize the separation process control.

[0115] The separation control device is configured to generate fluidization control commands based on the temperature, oil content, and solids content of the fluidized sludge before washing and separation, as well as the liquid level information in the washing and separation tank, according to a preset washing and separation temperature. These fluidization control commands include at least: a temperature control command, a water inflow control command, and a scraping action command. Simultaneously, the separation control device is also connected to a micro / nano bubble generator and a dosing device. The micro / nano bubbles generated by the micro / nano bubble generator and the chemicals added by the dosing device assist in demulsification and separation, improving separation accuracy.

[0116] Oil skimming structure 7: Installed near the top inside the water washing separator, it includes an adjustable-angle scraper and a scraper drive motor. The output of the scraper drive motor is connected to the adjustable-angle scraper via a spur gear, controlling the angle adjustment range of the scraper between 15° and 45°. By adjusting the scraper angle and scraping frequency, floating oil can be efficiently skimmed, ensuring that the water content of the floating oil is ≤10%.

[0117] The first temporary storage unit is used to store the sludge, sludge, and muddy water separated by the water washing and degreasing unit, so as to avoid mixing of sludge and sludge and facilitate subsequent sludge purification and sludge treatment.

[0118] The solid-liquid separation unit is used to separate the mud and oil sludge produced by the water washing and oil removal unit to obtain wastewater and tailings; it includes a conditioning and feeding tank and a vertical scraper centrifuge.

[0119] Conditioning and feeding tank: Equipped with an agitator and time relay. The agitator rotates at 50-60 r / min to mix the mud and water evenly, ensuring uniform properties for subsequent centrifugal separation. The outlet of the conditioning and feeding tank is connected to a centrifugal pump via a pipeline. The centrifugal pump has a flow rate of 10-15 m³ / h, an inlet-outlet pressure difference of 0.3-0.5 MPa, and a medium temperature controlled at 40-60℃. The outlet of the centrifugal pump is connected to the inlet of a vertical scraper centrifuge to transport the conditioned mud and water to the centrifuge.

[0120] The vertical scraper centrifuge includes a drum 14, a scraper system 15, and a three-phase outlet. The drum 14 is connected to a drum drive motor via a drive shaft. The drum drive motor provides power to rotate the drum 14 at high speed, thereby realizing the centrifugal separation process. The scraper system 15 includes scrapers and a scraper servo drive motor. Scrapers are installed inside the drum 14, and the scraper servo drive motor is installed on the top of the drum 14. The output end of the scraper servo drive motor extends into the drum 14 and is connected to the scrapers via a connecting rod. The angle between the scraper blade and the inner wall of the drum 14 is 15°-20°. The scraper servo drive motor controls the movement trajectory of the scrapers through the connecting rod to efficiently scrape away the mud phase accumulated on the inner wall of the drum 14, ensuring a clean separation surface. The three-phase outlets include oil phase outlet 5, water phase outlet 6 and mud phase outlet 4. Mud phase outlet 4 is located at the center of the bottom of the drum 14 and is used to receive mud phase material scraped off by the scraper. Oil phase outlet 5 and water phase outlet 6 are located on the side wall of the drum 14 and are at the same height, which facilitates the separation of light oil phase and heavy water phase according to density difference. The three outlets are connected to the sludge buffer tank, the solid waste tank and the classified sludge storage tank through pipelines respectively.

[0121] Linkage control: An oil phase electric valve is installed at oil phase outlet 5, which is linked to the online oil content detector on the oil phase outlet 5 pipeline. When the oil content of the sludge is ≥45%, the valve opens; when the oil content is <45%, the valve closes and the drum speed is increased. An aqueous phase electric valve is installed at aqueous phase outlet 6, which is linked to the online oil content detector on the aqueous phase outlet 6 pipeline. When the oil content of the wastewater is ≤10%, the valve opens; when the oil content is >10%, the valve closes and the drum speed is reduced. The scraper servo drive motor is linked to the moisture content detector and oil content detector at the solid-liquid separation unit outlet. When the tailings moisture content is ≤38% and the tailings oil content is ≤1.8%, the scraper 15 starts scraping sludge sequentially in the order of upper layer, middle layer, and lower layer at 30-second intervals, with a scraping interval of 2 minutes / time. Through linkage control, the accuracy and efficiency of solid-liquid separation can be ensured.

[0122] The second temporary storage unit is used to store the tailings generated by the solid-liquid separation unit, providing storage space for the subsequent disposal of the tailings (such as brick making, road paving, etc.).

[0123] The sludge purification unit is used to purify the sludge stored in the first temporary storage unit, removing impurities and moisture from the sludge, improving its purity, and enabling its recycling (e.g., as industrial fuel oil). Wastewater is generated during the purification process and is transported to the wastewater treatment unit for further treatment.

[0124] The waste oil purification unit includes a waste oil buffer tank and a centrifugal waste oil purifier. The speed of the centrifugal waste oil purifier is adjusted according to the oil content, and the oil content of the purified waste oil is ≥90%.

[0125] The wastewater treatment unit is used to treat wastewater generated by the solid-liquid separation unit and the oily wastewater purification unit. The wastewater treatment process includes pretreatment (bar filtration, 20mm filtration precision, removing suspended solids ≥20mm in diameter), chemical dosing and stirring, coagulation and sedimentation, dissolved air flotation, and tertiary filtration. The treated purified water has a reuse rate of ≥80%, with an oil content ≤50mg / L and suspended solids ≤85mg / L. The treated purified water can be recycled for oil-sludge separation, improving water resource utilization and reducing fresh water consumption.

[0126] Integrated processing system: Located within a single workshop, it is used to achieve "closed-loop operation of the entire process within the workshop". The workshop is functionally divided into raw material storage unit 1 on the left, intermediate equipment unit 2, tailings treatment unit 3 on the right, and auxiliary facilities units arranged around intermediate equipment unit 2. Each unit is connected to the others through short-path conveying channels with a maximum conveying path of no more than 20m.

[0127] Material conveying: Raw material storage unit 1 is equipped with a sludge pretreatment unit, which uses a grab bucket to convey fluidized sludge to intermediate equipment unit 2. Intermediate equipment unit 2 is sequentially connected to a water washing and oil removal unit, a solid-liquid separation unit, a sludge and oil purification unit, and a wastewater treatment unit. The sludge, oil, wastewater, and tailings generated by the water washing and oil removal unit and the solid-liquid separation unit are respectively conveyed through pipelines or conveyors to the sludge and oil purification unit, the wastewater treatment unit on the same side, and the tailings treatment unit on the right side. Through integrated layout, the material conveying path is shortened, the transfer time and loss are reduced, the processing efficiency is improved, and the footprint of the unit is reduced, saving site construction costs.

[0128] The intelligent control system includes a PLC control system and an execution module;

[0129] The PLC control system can generate control commands according to preset logic based on the data collected by the data acquisition device, such as feed flow rate, stirring speed, drum speed, drum liquid level, oil-water interface height, and oil and water content at each outlet. This controls the actions of the execution modules to achieve three-phase separation of oil, water, and sludge, ensuring that the tailings have a water content ≤38%, an oil content ≤1.8%, an oil content ≥45%, and an oil content ≤10% in the wastewater. Simultaneously, the PLC control system also achieves data interaction and collaborative control with the water washing and oil removal unit, the oil purification unit, and the wastewater treatment unit. It establishes a historical database and optimizes control parameters through machine learning to continuously improve processing efficiency and effectiveness.

[0130] Among them, the machine learning algorithm adopts the BP neural network (BackPropagation Neural Network) model. The training data consists of the processing parameters (temperature, oil content, water volume) and separation effect data of the past 12 months. The optimization objective function is "lowest oil content in tailings + lowest energy consumption".

[0131] Data acquisition device: includes electromagnetic flowmeter, temperature sensor, stirring speed sensor, drum speed sensor, liquid level sensor, oil-water interface meter, online oil content meter, and water content meter, used to collect processing parameters. Temperature sensors are installed in the conditioning and screening unit of raw material storage unit 1 and in each processing tank of equipment unit 2. Electromagnetic flowmeters are installed between the outlet of the conditioning feed tank and the centrifugal pump. Stirring speed sensors are installed inside the conditioning feed tank. Drum speed sensors are installed at the drum drive motor. Liquid level sensors are installed in each processing tank of the equipment unit. The oil-water interface meter is located in the area connecting oil phase outlet 5 and water phase outlet 6. Online oil content meters are installed at oil phase outlet 5, water phase outlet 6, and the solid-liquid separation unit outlet, respectively. The water content meter is installed at the solid-liquid separation unit outlet.

[0132] The execution module includes a centrifugal pump frequency converter, a drum drive motor frequency converter, an oil phase outlet electric valve, a water phase outlet electric valve, and a scraper servo drive motor. It is used to execute the control instructions generated by the PLC control system to achieve precise control of the processing process.

[0133] This oily sludge treatment method is based on an integrated treatment device. Through the coordinated operation of seven core stages—pretreatment, conditioning and screening, water washing and separation, solid-liquid separation, oil purification, wastewater treatment, and residue disposal—it achieves efficient treatment and resource recovery of oily sludge. Each stage is closely linked, forming a complete closed loop. The specific steps are as follows:

[0134] The pretreatment stage aims to remove large impurities from oily sludge and break up bagged sludge to provide homogenized raw materials for subsequent treatment. Specifically, it includes: 1. Classification: The oily sludge is classified according to its morphology. For bagged oily sludge, it is first crushed by shredder 8 (model TSJ-800). Shredder 8 adopts a dual-shaft shearing design with a rotation speed of 15-20 r / min, which can crush bagged oily sludge into blocks with a particle size ≤100mm, breaking the packaging and initially dispersing the sludge. For non-bagged or low-impurity oily sludge, it is directly conveyed to grid 10 for processing. 2. Multi-stage screening: The crushed bagged oil sludge falls into the lower cross screen 9. The screen surface consists of multiple sets of screen shafts rotating in the same direction, with the screen plates of adjacent screen shafts arranged in a cross pattern. The screen aperture size is 50×50mm, which can effectively separate large impurities (particle size ≥50mm) such as stones and metal pieces from the sludge. Non-bagged oil sludge undergoes preliminary screening through the grid 10 (grid spacing 50mm) to remove large impurities. The screened impurities are collected and sent to the hazardous waste disposal center for professional treatment. 3. Conveying and temporary storage: The qualified sludge after screening is conveyed by a scraper conveyor (conveyor speed 0.8m / s) to the temporary storage tank (volume 10m³) of the raw material storage unit 1. The temporary storage tank is equipped with a stirring device (speed 20r / min) to prevent sludge settling and stratification, ensuring the continuity of subsequent treatment.

[0135] The conditioning and screening process improves sludge flowability through heating and homogenization, creating favorable conditions for water washing and separation. The specific steps are as follows: 1. Heating: Sludge in the temporary storage tank is transported to the heating and feeding tank 11 (5m³) via a hopper on a crane. A steam coil 13 (DN50 diameter) is installed in the tank, through which low-pressure steam at 0.2-0.4MPa and 120-150℃ is continuously introduced for 20-30 minutes to heat the sludge. A PT100 temperature sensor is installed in the tank, linked to a PLC control system. When the sludge temperature is below 15℃, the steam valve automatically opens for heating; when the temperature reaches 20℃, the steam valve closes, maintaining the sludge temperature within the 15-20℃ range and reducing sludge viscosity. 2. Secondary Conditioning: The heated sludge overflows into the conditioning and feeding tank 12 (5m³), which is also equipped with a steam coil 13 and a temperature sensor to ensure stable sludge temperature. At the same time, start the stirring device in the tank (30r / min) to continuously stir the sludge for 20-30 minutes to make the sludge texture uniform, avoid local caking, and form homogenized fluidized sludge.

[0136] The water washing and separation process is the core step in achieving the initial separation of oil and sludge. Through chemical assistance, bubble demulsification, and oil skimming, most of the sludge and oil is separated. The specific process is as follows: 1. Feeding and Chemical Dosing: Fluidized sludge is pumped into the water washing and separation tank (10m³ volume). Simultaneously, the dosing device is activated, and a bio-based chemical (mainly modified starch derivatives) is added at 0.5%-1.5% of the sludge suspension mass. The chemical enters the tank synchronously with the sludge through pipelines and is rapidly mixed under the action of a stirring device (30r / min), breaking down the colloidal structure of the sludge and promoting oil-water separation. 2. Micro-nano bubble-assisted demulsification: The micro-nano bubble generator (model MNB-500) installed at the bottom of the water washing and separation tank is activated, generating micro-nano bubbles with a diameter of 50-100μm. As the bubbles rise, they collide and adsorb with oil droplets, forming larger oil bubble aggregates and accelerating the formation of the floating oil layer. The bubble generator operates at a pressure of 0.3-0.5 MPa and a flow rate of 1-2 m³ / h for 30 minutes. 3. Settling and Separation: Stop stirring and the bubble generator, allowing the mixture to settle and separate into layers for 40-60 minutes. Under gravity, the mixture gradually separates into three layers: an upper layer of floating oil (oil content ≥45%), a middle layer of aqueous phase, and a lower layer of sludge (higher solids content). The data acquisition device monitors the thickness of each layer in real time. When the floating oil layer thickness reaches 10 mm or more, the floating oil scraping program is initiated. 4. Floating Oil Scraping: The scraper parameters are automatically adjusted according to the floating oil layer thickness: when the floating oil layer thickness is 10-20 mm, the scraper angle is adjusted to 30°, and the scraping frequency is 2 times / minute; when the thickness is >20 mm, the angle is adjusted to 15°, and the frequency is increased to 3 times / minute; when the thickness is <10 mm, the angle is adjusted to 45°, and the frequency is reduced to 1 time / minute. The scraped oil is transported through pipelines to a sludge storage tank (5m³). During the scraping process, the oil-water interface is monitored in real time to ensure that the water content of the oil is ≤10%. 5. Oil sludge and mud-water treatment: After the oil is scraped and separated, the lower layer of oil sludge (solid content 30%-40%) and the middle layer of mud-water are mixed evenly and then pumped to the solid-liquid separation unit for solid-liquid separation.

[0137] The solid-liquid separation process utilizes centrifugal separation technology to further separate the oil, water, and sludge phases in the mud-water and oil sludge, improving separation accuracy. The specific steps are as follows: 1. Conditioning and Feeding: The stirred mud-water and oil sludge are pumped (flow rate 12 m³ / h) to a conditioning and feeding tank (volume 3 m³). An agitator (speed 55 r / min) continuously stirs the mixture inside the tank, while a small amount of flocculant (polyacrylamide, dosage 0.1%) is added to promote the agglomeration of small particles and enhance the centrifugal separation effect. The conditioning time is controlled at 20 minutes to ensure uniform mud-water properties. 2. Centrifugal Separation: The conditioned sludge is continuously fed into a vertical scraper centrifuge (model LW450×1800N) via a feed pump (flow rate 10 m³ / h). The drum speed is set to 3000 r / min. Under centrifugal force (approximately 1200 G), the sludge is separated into three phases: a light oil phase (density < 0.9 g / cm³), a water phase (density 1.0-1.03 g / cm³), and a heavy sludge phase (density > 1.2 g / cm³). 3. Phase Discharge: The three phase outlets of the vertical scraper centrifuge are equipped with online detection devices and automatic valves. An online oil content detector is installed at oil phase outlet 5. When the oil content is detected to be ≥ 45%, the oil phase electric valve is automatically opened, discharging the sludge into the wastewater discharge system. Oil buffer tank; when the oil content is <45%, the valve is closed and the drum speed is automatically increased (maximum 3500 r / min) until the oil content meets the standard; an online oil content detector is installed at the aqueous phase outlet 6. When the oil content is ≤10%, the aqueous phase electric valve is opened to discharge the wastewater into the solid waste tank; when the oil content is >10%, the valve is closed and the feed rate is adjusted until the water quality meets the standard before discharge; a moisture content detector and an oil content detector are installed at the mud phase outlet 4. When the tailings moisture content is ≤38% and the oil content is ≤1.8%, the scraper starts scraping mud in the order of upper layer, middle layer, and lower layer at 30-second intervals, with a scraping interval of 2 minutes / time; if the indicators do not meet the standard, the scraping interval is shortened to 1.5 minutes / time, and the drum speed is adjusted. 4. Temporary Material Storage: The separated sludge is temporarily stored in a sludge buffer tank (3m³), the wastewater is temporarily stored in a solid wastewater tank (10m³), and the tailings are temporarily stored in a classified sludge storage tank (5m³), awaiting further treatment. The sludge buffer tank, solid wastewater tank, and classified sludge storage tank are located on the same side as the solid-liquid separation unit and within equipment unit 2;

[0138] The waste oil purification process involves deep treatment of the separated waste oil to improve oil purity and achieve resource recovery. The specific process is as follows: 1. Waste oil collection: An online oil content detector in the waste oil buffer tank collects the oil content of the waste oil in real time. The waste oil in the waste oil temporary storage tank and the waste oil buffer tank (total oil content 45%-60%) is centrally transported to the pretreatment tank (volume 3m³) of the waste oil purification unit through a gear pump (flow rate 5m³ / h). The pretreatment tank is equipped with a heating coil to heat the waste oil to 40-50℃ to reduce its viscosity. 2. Centrifugal purification: The heated waste oil is sent to a centrifugal waste oil purifier (model LW350×1320N) through a feed pump (flow rate 3m³ / h). The speed is adjusted according to the initial oil content of the waste oil: when the oil content is 45%-50%, the speed is set to 3500r / min; when the oil content is 50%-60%, the speed is set to 4000r / min. Under centrifugal force, water and fine impurities in the sludge are separated, and the oil content of the purified sludge is ≥90%. 3. Purified oil storage: The purified qualified oil is transported through pipelines to a closed underground pool (10m³) for storage. The pool is equipped with a level gauge and a temperature control system (maintaining a temperature of 30-40℃) to prevent the oil from solidifying. The stored purified oil can be sold as industrial fuel oil or used internally, realizing resource recycling. 4. Purified wastewater discharge: Wastewater (oil content 10%-20%) generated during the centrifugal purification process is transported through pipelines to a solid wastewater pool, where it is combined with the wastewater generated in the solid-liquid separation stage for treatment.

[0139] The wastewater treatment process involves advanced treatment of wastewater generated at each stage to achieve water recycling. The specific steps are as follows: 1. Wastewater Collection and Pretreatment: Wastewater from the solids-containing wastewater tank (mainly from solid-liquid separation and oil purification stages) is pumped to a bar screen (20mm spacing) via a lift pump (flow rate 15m³ / h) to remove suspended impurities and fibrous materials, protecting subsequent treatment equipment. 2. Coagulation and Sedimentation: The pretreated wastewater enters a dosing tank (2m³), where polyaluminum chloride (50-80mg / L) and polyacrylamide (5-10mg / L) are added. The mixture reacts for 20 minutes under the action of a stirrer (40r / min), forming large flocs. The wastewater then enters a coagulation and sedimentation tank (5m³), where the flocs settle under gravity for 30 minutes. The supernatant overflows to the next stage, and the bottom sludge is pumped to a classified sludge storage tank. 3. Dissolved Air Flotation (DAF): The supernatant from the sedimentation tank enters the DAF machine (model QF-5). Microbubbles (20-50μm in diameter) generated by the dissolved air system adsorb tiny oil droplets and suspended solids in the water. The bubbles carry pollutants to the surface, forming scum, which is scraped off by a scum scraper (scum moisture content 95%-98%, transported to an oil sludge storage tank). The effluent after DAF treatment has an oil content ≤55mg / L and suspended solids ≤90mg / L. 4. Three-Stage Filtration: The DAF effluent sequentially enters a quartz sand filter (0.8-1.2mm particle size), an activated carbon filter (1-2mm particle size), and a precision filter (5-10μm filtration accuracy) to further remove residual oil, organic matter, and fine particulate matter, ensuring the effluent meets quality standards (oil content ≤50mg / L, suspended solids ≤85mg / L). 5. Recycling: The recycled water after three-stage filtration is stored in a recycled water tank (10m³), and then pumped to the water washing and oil removal unit and sludge pretreatment unit through a recycled water pump (flow rate 20m³ / h). It is recycled for the separation of oil and sludge containing oil, with a recycling rate of ≥80%. The remaining part is discharged in compliance with the Class I standard of the Integrated Wastewater Discharge Standard GB8978-1996.

[0140] The residue disposal process involves the resource utilization or harmless treatment of various solid residues generated during the processing. The specific steps are as follows: 1. Tailings collection: Tailings from the classified sludge storage tanks (mainly from solid-liquid separation and coagulation sedimentation stages) are centrally transported to the residue treatment area via a screw conveyor (conveying capacity 5m³ / h). The tailings have a moisture content ≤38% and an oil content ≤1.8%, meeting the conditions for resource utilization. 2. Tailings brick making: The tailings are mixed with cement and sand in a mass ratio of 6:2:2, with the addition of an appropriate amount of recycled water (water-cement ratio 0.4-0.5). After thorough mixing, the mixture is fed into a brick-making machine (model QTJ4-25) for pressing and molding. After natural curing for 7 days, the bricks achieve a strength of MU10 or higher and can be used for non-load-bearing walls or paving materials. 3. Wastewater Sludge Treatment: Wastewater sludge (80%-85% moisture content) generated from the coagulation sedimentation tank is dewatered to ≤60% moisture content using a plate and frame filter press (50㎡ filtration area), and then sent to a pyrolysis furnace (500-600℃) for thermal desorption to remove residual oil (pyrolysis gas is collected and used as fuel). The ash from pyrolysis is mixed with a solidifying agent (cement) at a mass ratio of 8:2 and used for brick making or roadbed filling. 4. Hazardous Waste Disposal: Large impurities, flotation scum, and other wastes that do not meet the conditions for resource utilization separated in the pretreatment stage are handed over to qualified hazardous waste disposal units for safe disposal (such as incineration or safe landfill) in accordance with hazardous waste management requirements to ensure no environmental pollution. Through the coordinated operation of the above seven stages, this treatment method achieves "reduction, harmlessness, and resource utilization" of oily sludge. Each stage ensures treatment efficiency and separation accuracy through short-path transportation (maximum ≤20m) and intelligent collaborative control, while taking into account environmental performance and economy.

[0141] In specific implementation, the oily sludge treatment device of the present invention includes a sludge pretreatment unit: the pre-screening unit includes a shredder 8 (model: TSJ-800), a cross screen 9 (screen shaft speed: 65r / min) and a grid 10 (grid spacing: 50mm).

[0142] The conditioning and screening unit includes a heating feeding tank 11 (volume: 5m³) and a conditioning feeding tank 12 (volume: 5m³). Both tanks are equipped with steam coils 13 (pipe diameter: DN50) that are heated by low-pressure steam of 0.3MPa. PT100 temperature sensors are installed in the tanks and connected to the PLC control system (model: S7-1200).

[0143] The water washing and oil removal unit consists of a water washing separation tank (volume: 10m³) equipped with an internal stirring device (stirring speed: 30r / min). An adjustable-angle oil scraper (angle adjustment range: 15°-45°) and a scraper drive motor (model: Y90S-4) are installed near the top of the tank. Data acquisition devices include a temperature sensor (PT100), an online oil content analyzer (model: OIL-800), a solids content analyzer (model: TSC-200), and a liquid level sensor (model: LT-800). The separation control device is connected to a micro / nano bubble generator (model: MNB-500) and a dosing device (model: JY-1000). The dosing device adds a bio-based agent (mainly a modified starch derivative with a molecular weight of 10000-20000Da, added at a rate of 0.5%-1.5% of the oil sludge suspension mass).

[0144] Solid-liquid separation unit: conditioning and feeding tank (volume: 3m³), with a stirrer (speed: 55r / min) and time relay; centrifugal pump (model: ISG100-160, flow rate: 12m³ / h); vertical scraper centrifuge (model: LW450×1800N), drum speed: 3000r / min, scraper system 15 includes scraper and scraper servo drive motor (model: MSME102G1V), the angle between the scraper blade and the inner wall of the drum 14 is 18°; the three-phase outlet is equipped with an online oil content detector (OIL-800) and an electric valve (model: Z941H-16C).

[0145] Oily waste purification unit: adopts centrifugal oily waste purifier (model: LW350×1320N), speed: 4000r / min;

[0146] Wastewater treatment unit: includes pretreatment bar screen (grid spacing: 20mm), dosing and mixing tank (volume: 2m³, mixing speed: 40r / min), coagulation sedimentation tank (volume: 5m³), dissolved air flotation unit (model: QF-5) and three-stage filtration device (quartz sand filter, activated carbon filter, precision filter).

[0147] Integrated processing system: Workshop dimensions: 50m long × 30m wide × 8m high, with raw material storage unit 1 on the left (area: 100㎡), intermediate equipment unit 2 (area: 300㎡), tailings treatment unit 3 on the right (area: 80㎡), and auxiliary facilities unit (area: 120㎡). All units are connected by a conveyor channel (maximum: 18m). Intelligent control system: PLC control system (S7-1200), data acquisition devices include electromagnetic flowmeter (model: LDG-100), stirring speed sensor (model: RS-200), drum speed sensor (model: RS-300), oil-water interface meter (model: OWI-500), and moisture content meter (model: MC-780). Execution modules include centrifugal pump frequency converter (model: ACS510), drum drive motor frequency converter (model: ACS510), electric valves, and scraper servo drive motors.

[0148] The method for treating oily sludge of the present invention specifically includes:

[0149] Step 1, Pretreatment: Bagged oily sludge is shredded by shredder 8 and then screened by cross screen 9. Non-bagged oily sludge is screened by grid 10. The screened sludge is fed into heating tank 11 and conditioning tank 12 through the hopper on the crane. When the temperature is below 15℃, steam coil 13 is turned on to heat the sludge. When the temperature reaches 20℃, it is turned off. Then, homogenization is carried out.

[0150] Step 2, Water washing and oil separation: The homogenized fluidized sludge is pumped into the water washing and separation tank, and a bio-based agent is added (dosage: 1.0% of the mass of the oil sludge suspension). The micro-nano bubble generator and stirring device are started, and the mixture is stirred for 30 minutes and then allowed to stand to separate into layers. When the thickness of the floating oil layer reaches 12 mm, the oil scraper is started, the angle is adjusted to 30°, and the scraping frequency is 2 times / minute. The separated sludge and oily waste are stored in the first temporary storage unit (sludge storage tank: 5 m³, oily waste storage tank: 5 m³).

[0151] Step 3, Solid-Liquid Separation: After the mud and water and oil sludge are mixed evenly, they are pumped into the conditioning and feeding tank and stirred for 20 minutes. Then, they are pumped into a vertical scraper centrifuge with a drum speed of 3000 r / min. When the oil content at oil phase outlet 5 is ≥45%, the electric valve is opened. When the oil content at water phase outlet 6 is ≤10%, the electric valve is opened. When the water content of the tailings at mud phase outlet 4 is ≤38% and the oil content of the tailings is ≤1.8%, the scraper scrapes the mud in the order of upper layer, middle layer, and lower layer at 30-second intervals, with a scraping interval of 2 minutes / time. The separated oil phase is sent to the sludge-oil buffer tank, the water phase is sent to the solid waste tank, and the mud phase is sent to the classified sludge storage tank.

[0152] Step 4, Oil and Waste Purification: The oil and waste is sent to a centrifugal oil and waste purifier with a rotation speed of 4000 r / min. After purification, the oil content of the oil and waste is ≥90%. The oil and waste is stored in a closed underground tank (volume: 10 m³). The wastewater generated during purification is sent to the wastewater treatment unit.

[0153] Step 5, Wastewater Treatment: After passing through the pretreatment screen, the wastewater enters the dosing and mixing tank where polyaluminum chloride (dosage: 50mg / L) is added. After stirring for 20 minutes, it enters the coagulation sedimentation tank. After settling for 30 minutes, the supernatant enters the dissolved air flotation machine. After flotation, the effluent enters the three-stage filtration device. The treated water quality is: oil content ≤5mg / L, which is reused in the water washing and oil removal unit.

[0154] Step 6, Residue Disposal: Washed tailings (35% moisture content, 1.5% oil content) are used for brick making. Wastewater sludge is desorbed by pyrolysis (temperature: 500℃), and pyrolysis ash is mixed with cement (mass ratio: 8:2) to make bricks.

[0155] It should be noted that the feasibility of tailings resource utilization is as follows: the heavy metal content (Pb≤0.1mg / kg, Cr≤0.05mg / kg) of the water-washed tailings meets the requirements of the "Soil Environmental Quality Standard for Construction Land Soil Pollution Risk Control" (GB36600-2018), and the compressive strength is ≥10MPa, which meets the requirements for brick making. The testing method refers to the "Solid Waste Leaching Toxicity Leaching Method Sulfuric Acid Nitric Acid Method" (HJ / T299-2007).

[0156] The results of the example demonstrate the following separation accuracy of the oily sludge treatment device: Water washing tailings moisture content: 32%-36%, oil content: 1.2%-1.6%; separated sludge oil content: 48%-52%; separated wastewater oil content: 6%-9%; floating oil scraping rate: 96%-98%, floating oil moisture content: 7%-9%.

[0157] Energy consumption: The energy consumption for processing 1 ton of oily sludge is as follows: electricity: 8 kWh, steam: 0.1 t, fresh water: 0.5 t, which is 35% lower than the energy consumption of traditional processes;

[0158] Resource recycling: Sewage oil recovery rate: 85%-90%, wastewater treatment reuse rate: 82%-85%, tailings resource utilization rate: 92%-95%;

[0159] Processing efficiency: A single unit can process 120 tons of oily sludge per day, with a processing cycle of 2 hours per batch, which is 22% shorter than the traditional process.

[0160] Floor space occupied: 4,500㎡ for a single unit, saving 25% compared to the traditional distributed layout (6,000㎡).

[0161] It is worth noting that the oily sludge treatment device of the present invention has the following characteristics: (1) High separation accuracy: Multi-unit collaboration achieves precise three-phase separation. The present invention starts from the entire process of oily sludge treatment and constructs a high-precision separation system through the collaborative cooperation of various unit technologies, which is significantly better than traditional treatment technologies. In the pretreatment stage, the sludge pretreatment unit performs three-stage treatment of "shredding-screening-conditioning". First, the shredder 8 is used to crush bagged oily sludge, and the cross screen 9 (screen shafts are arranged in a cross pattern) and grid 10 are used to remove impurities. Then, the sludge is heated to 15-20℃ by low-pressure steam (0.2-0.4MPa) to reduce the viscosity of the sludge, improve the flowability and uniformity of the material, and lay the foundation for subsequent separation. In the water washing and oil removal stage, the water washing separation tank combines a bio-based agent (dosage 0.5%-1.5%) with a micro-nano bubble generator to assist in demulsification. The bio-based agent can efficiently destroy the colloidal structure of the oil sludge, while the micro-nano bubbles enhance the oil-water separation effect by increasing the contact area. Combined with an adjustable-angle oil skimming structure 7 (angle adjustable from 15° to 45°), the skimming frequency (1-3 times / minute) is dynamically adjusted according to the thickness of the oil layer, ultimately achieving an oil skimming rate of ≥95% and a water content of ≤10%, avoiding the problems of "incomplete skimming" or "excessive water carryover" found in traditional oil skimming devices. The solid-liquid separation unit, as a key component for precision control, employs a vertical scraper centrifuge combined with online detection and linkage control technology. The vertical scraper centrifuge's drum 14 rotates at high speed (above 3000 r / min), generating strong centrifugal force. Combined with the 15°-20° angle between the scraper and the inner wall of the drum 14, it effectively scrapes away the mud phase in layers, ensuring thorough separation of the tailings. Online oil content detectors are installed at the oil phase outlet 5 and the water phase outlet 6, respectively. These detectors are linked to electric valves. When the oil content of the wastewater is ≥45%, oil discharge is initiated; when the oil content is <45%, the drum speed is adjusted; when the oil content is ≤10%, drainage is initiated; and when the oil content is >10%, the machine is shut down for optimization. Ultimately, this achieves a tailings moisture content ≤38%, a tailings oil content ≤1.8%, and a wastewater oil content ≤10%. Compared to traditional single-stage centrifuges (where the tailings oil content often exceeds 5%), this invention improves separation accuracy by over 60%, meeting stringent environmental emission and resource recovery requirements.

[0162] Low energy consumption and low pollution: Green treatment mode reduces environmental burden. In terms of energy consumption control, this invention achieves energy saving and consumption reduction through a triple measure of "integrated layout + precise temperature control + recycling". The device adopts an integrated workshop design, with each unit connected by a short-path conveying channel with a maximum length of ≤20m, shortening the distance by more than 60% compared to the traditional decentralized layout (the conveying path often exceeds 50m), reducing the operating energy consumption of conveying equipment such as scraper conveyors and centrifugal pumps; only when the sludge viscosity is high in winter, the sludge is heated to 15-20℃ through steam coil 13, and the treatment needs can be met by relying on the ambient temperature in other seasons, reducing energy consumption by more than 30% compared to the traditional high-temperature pyrolysis process (which requires heating to above 300℃). At the same time, the wastewater treatment unit improves the wastewater reuse rate to ≥80% through the process of "pretreatment-coagulation sedimentation-dissolved air flotation-three-stage filtration", and a single unit can save 292,000 m³ of fresh water per year, significantly reducing water resource consumption. In the field of pollution control and resource recycling, this invention comprehensively replaces traditional high-pollution treatment methods: it uses bio-based agents (such as modified starch) to replace chemical demulsifiers, and the agents are biodegradable, avoiding secondary pollution of soil and groundwater by chemical residues; the resource utilization rate of tailings is ≥90%, and the water-washed tailings (moisture content ≤38%, oil content ≤1.8%) can be directly used for brick making or road paving. After thermal desorption, the wastewater sludge is mixed with a solidifying agent to make bricks, realizing a closed-loop treatment of solid waste "reduction-harmlessness-resource utilization"; the waste oil has an oil content of ≥90% after purification and can be recycled as industrial fuel oil, with an annual recovery of approximately 1,800 tons of purified oil (calculated based on an oil content of 5% in oily sludge and a recovery rate of 80%), reducing the environmental risk of direct discharge of waste oil.

[0163] High Processing Efficiency: Optimized Entire Process Enhances Capacity. This invention significantly improves the processing efficiency of oily sludge through unit technology upgrades and process synergy. The water washing and oil removal unit optimizes control logic, adopting a sequential execution strategy of "influent flow priority - temperature control - scraping action," combined with a dynamic flow algorithm (Q=K×(V×ρ×S) / T, K=1.2-1.5) to achieve stepped influent, avoiding the time waste of the traditional "fixed influent + constant temperature waiting" mode, shortening the processing cycle by 20%. The entire process is automated using a PLC control system, from sludge feeding, reagent addition, centrifugation to wastewater reuse, requiring no manual intervention. This not only reduces the intensity of manual operation but also avoids process interruptions caused by human error, increasing the equipment continuous operation rate to over 95%. In terms of capacity, the annual processing capacity of a single unit increases from 30,000 tons of traditional processes to 36,000 tons, a 20% increase in processing capacity. Taking a device that processes 120 tons of oily sludge per day as an example, traditional processes require 24-hour full-load operation. However, this invention, through the design of "parallel screening" in the sludge pretreatment unit (shredder 8 + cross screen 9 + grid 10 operating simultaneously) and "continuous centrifugation" in the solid-liquid separation unit (vertical scraper centrifuge does not require frequent shutdowns for slag discharge), can complete the daily processing task within 20 hours, leaving sufficient time for equipment maintenance and further ensuring long-term stable operation.

[0164] High Space Utilization: Compact Layout Reduces Site Costs. This invention significantly improves the space utilization rate of the equipment through "functional zoning optimization + three-dimensional space utilization". The workshop adopts a layout of "left-side raw material storage unit 1 + middle equipment unit 2 + right-side tailings treatment unit 3 + surrounding auxiliary facilities". Raw materials enter from the left, and after pretreatment, water washing and oil removal, solid-liquid separation and other processes, tailings are discharged from the right, forming a "one-line" linear process, avoiding the problems of "circuitous transportation and cross-occupancy" in traditional decentralized layouts. A single unit occupies ≤4500㎡, saving 25% of space compared to the traditional decentralized layout (≥6000㎡). Calculated at an industrial land price of 200,000 yuan / mu, a single unit can save ≥450,000 yuan in land costs (traditional layouts require ≥9 mu, while this invention only requires ≤6.75 ​​mu). In terms of spatial design, auxiliary facilities (control room, power distribution room, and reagent storage room) are arranged around the intermediate equipment unit 2, utilizing the space between equipment to avoid the waste of land required by building separate auxiliary workshops. A closed underground tank (for storing sludge and wastewater) is located below the vertical scraper centrifuge, utilizing the space beneath the equipment to replace traditional ground-level decentralized storage tanks (requiring 100-150㎡ of space). Vertical structures are prioritized for equipment selection; for example, the vertical scraper centrifuge occupies only 60% of the area of ​​a horizontal centrifuge, and the water washing separation tank adopts a vertical design, utilizing space vertically to reduce horizontal footprint. For older factories or projects in urban areas with limited space, this device does not require large-scale land acquisition or renovation, shortening the project construction period from the traditional 12 months to 8 months, rapidly improving sludge treatment capacity.

[0165] High degree of automation and intelligence: Precise control ensures processing stability. The intelligent control system of this invention constructs a complete closed loop of "data acquisition - logical operation - execution feedback - parameter optimization". The data acquisition device covers key parameters throughout the entire process, including raw material temperature, sludge solids content, oil layer thickness, oil / water content at each outlet, etc. The sensor sampling frequency reaches 1 time / second to ensure real-time data. The PLC control system (such as S7-1200) generates control commands according to preset logic based on the acquired data, and controls the actions of the execution modules (centrifugal pump frequency converter, drum drive motor frequency converter, electric valve, etc.). For example, when the oil skimming rate is <90%, the angle and frequency of the oil skimmer are automatically corrected; when the temperature deviation is >2℃, the steam heating power is adjusted, and the control command execution error is ≤5%. The system also possesses collaborative control and self-optimization capabilities. The PLC control system interacts with the water washing and oil removal, sludge purification, and wastewater treatment units. For example, when the water quality in the wastewater treatment unit fails to meet standards, the system automatically adjusts the influent flow and reagent dosage of the water washing and oil removal unit to avoid "a single unit failure affecting the entire process." A historical database is established to record operational data, and machine learning is used to analyze the optimal control parameters corresponding to different sludge properties (oil content, solids content). For example, for high-oil-content sludge (oil content > 20%), the system automatically increases the heating power and reagent dosage, improving treatment stability by 40% and ensuring that different batches and different types of oil-containing sludge can achieve stable separation results.

[0166] Economic Feasibility: Significant Life Cycle Cost Advantages. This invention establishes significant economic advantages in terms of construction costs, operating costs, and return on investment. Regarding construction costs, shared and integrated auxiliary facilities, with control rooms and power distribution rooms serving all equipment in the workshop, replace the traditional separate operating rooms and power distribution rooms for each unit, reducing electrical equipment investment by approximately 30% (from 500,000 RMB to below 350,000 RMB); centralized storage in closed underground pools replaces decentralized storage pools, reducing civil engineering investment by 40% (from 800,000 RMB to below 480,000 RMB); and the construction cost of auxiliary facilities for a single unit is reduced from the traditional 2 million RMB to below 1.4 million RMB, saving 30% in investment. In terms of operating costs, the improved treatment efficiency reduces unit fixed costs (labor and equipment depreciation) by 20% (from RMB 150 / ton to RMB 120 / ton); reduced energy consumption and wastewater reuse save 547,500 kWh of electricity and 292,000 m³ of fresh water annually, resulting in annual energy and water savings of approximately RMB 1.898 million, with unit energy costs decreasing from RMB 80 / ton to RMB 60 / ton; the overall treatment cost decreases from RMB 300 / ton for traditional processes to RMB 240-255 / ton, and annual sludge treatment of 36,000 tons of sludge can save RMB 1.62 million to RMB 2.16 million. In terms of revenue return, approximately 1,800 tons of purified oil are recycled annually, generating an annual oil revenue of 7.2 million yuan based on an industrial fuel oil price of 4,000 yuan / ton; 13,500 tons of tailings are utilized annually, generating an annual resource revenue of 675,000 yuan based on a brick-making raw material price of 50 yuan / ton; the total revenue from these two items is 7.875 million yuan, far exceeding the annual operating cost (approximately 8.82 million to 9.18 million yuan, calculated at 240-255 yuan / ton × 36,000 tons), achieving the dual goals of "environmental compliance + economic profitability".

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oily sludge treatment device, characterized in that, include: The sludge pretreatment unit is used to fluidize and separate impurities from oily sludge to obtain fluidized sludge. The water washing and oil removal unit is used to separate the fluidized sludge from the oil to obtain sludge oil, oily sludge, and muddy water. The water washing and oil removal unit includes a water washing separation tank, which is connected to a data acquisition device and a separation control device. The separation control device is also connected to a micro-nano bubble generator and a dosing device. An oil skimming structure is installed near the top of the water washing separation tank; the data acquisition device is used to collect the temperature, oil content, and solids content of the fluidized sludge, as well as the liquid level information in the water washing separation tank. The separation control device is configured to generate fluidization control commands based on the temperature, oil content, and solids content of the fluidized sludge before water washing and the liquid level information in the water washing separation tank, according to a preset water washing separation temperature. The fluidization control commands include at least: a temperature control command, a water inflow control command, and a scraping action command. Based on the fluidization control commands, water washing is introduced into the water washing separation tank to control the temperature of the separation process and separate the floating oil. After the floating oil is separated, the oil sludge and the mud-water are discharged. First temporary storage unit: used to store the sludge, oil sludge and mud water separated by the water washing and degreasing unit respectively; A solid-liquid separation unit is used to separate the mud and water and the oil sludge into solid and liquid components to obtain wastewater and tailings. The second temporary storage unit is used to store the tailings generated by the solid-liquid separation unit. The waste oil purification unit is used to purify the waste oil, and wastewater will be generated during the purification process. Wastewater treatment unit, used to treat the wastewater and recycle it for sludge-oil separation of the oily sludge; The device also includes an integrated processing system and an intelligent control system; The integrated processing system is set up in a single workshop to achieve "closed-loop operation of the entire process within the workshop"; The workshop is functionally divided into a raw material storage unit on the left, an intermediate equipment unit, a tailings treatment unit on the right, and auxiliary facilities units surrounding the intermediate equipment unit. Each unit is interconnected by a short-path conveying channel with a maximum conveying path of 20m. The raw material storage unit houses the sludge pretreatment unit, which uses a grab bucket to transport fluidized sludge from the sludge pretreatment unit to the intermediate equipment unit. The intermediate equipment unit is sequentially connected to the water washing and oil removal unit, the solid-liquid separation unit, the sludge and oil purification unit, and the wastewater treatment unit. The sludge, oil, wastewater, and tailings generated by the water washing and oil removal unit and the solid-liquid separation unit are respectively transported through pipelines or conveyors to the sludge and oil purification unit, the wastewater treatment unit, and the tailings treatment unit on the right side. The water washing separation tank is also equipped with a stirring device, which controls the fluidization process to ensure that the sludge is mixed evenly. The intelligent control system includes a PLC control system and an execution module. The PLC control system generates control commands according to preset logic based on the data collected by the data acquisition device, and controls the execution module to achieve three-phase separation of oil, water and mud, ensuring that the water content of the tailings is ≤38%, the oil content of the tailings is ≤1.8%, the oil content of the sludge is ≥45%, and the oil content of the wastewater is ≤10%. At the same time, the PLC control system is also connected to the water washing and oil removal unit, the sludge purification unit and the wastewater treatment unit to realize data interaction and collaborative control, and establish a historical database to optimize control parameters through machine learning. The separation control device is configured as follows: based on data collected by the data acquisition device, the preset water washing separation reference temperature is 25-30℃. When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is >20% and the solid content is <30%, the heating power of the steam coil is adjusted to the rated power. When the temperature of the fluidized sludge is lower than the preset water washing separation reference temperature, and the oil content is ≤20% or the solid content is ≥30%, the heating power of the steam coil is adjusted to 60% of the rated power. When the temperature of the fluidized sludge is higher than the preset water washing separation reference temperature, the device switches to constant temperature mode and maintains the heating power of the steam coil at 20% of the rated power. A three-dimensional coupling model is thus established, and temperature control commands are generated based on the three-dimensional coupling model. Simultaneously, a dynamic flow algorithm is used to generate influent control commands, achieving stepped influent. The dynamic flow algorithm expression is: Q=K×V / T, where Q is the dynamic flow rate, K is the flow coefficient, V is the effective volume of the water washing separation tank, and T is the water washing separation cycle. When the oil layer thickness is less than the minimum oil scraping thickness, the oil scraper angle is adjusted to 45°, and the scraping frequency is set to 1 time / minute. When the oil layer thickness is between the minimum and maximum oil scraping thickness, the oil scraper angle is adjusted to 30°, and the scraping frequency is 2 times / minute. When the oil layer thickness reaches the maximum oil scraping thickness, the oil scraper angle is adjusted to 15°, and the scraping frequency is increased to 3 times / minute, constructing a linkage control logic. Based on this logic, scraping action commands are generated, the command execution timing is optimized, and parameters are corrected through feedback to ensure that the control command execution error is ≤5%. At the same time, the separation control device is linked with the dosing device and the micro-nano bubble generator, and data sharing is achieved with the sludge and oil purification unit and the wastewater treatment unit. The water inlet control command is executed first. After the liquid level in the water washing separator reaches the preset value, the temperature control command is activated. When the temperature is stable and the thickness of the floating oil layer is greater than the preset thickness, the scraping action command is executed. The real-time feedback correction logic is as follows: when the temperature deviation is >2℃, the heating power of the steam coil is adjusted; when the floating oil scraping rate is <90%, the oil scraping parameters are corrected; when the water inlet deviation is >10%, a fault alarm is triggered.

2. The oily sludge treatment device according to claim 1, characterized in that, The sludge pretreatment unit consists of a pre-screening unit and a conditioning screening unit; The pre-screening unit includes a shredder, a cross screen, and a grid. The shredder is used to process bagged oily sludge. The cross screen is located below the shredder, and its screen surface consists of multiple sets of screen shafts rotating in the same direction, with the screen plates of adjacent screen shafts arranged in a cross pattern. The grid is used for preliminary screening of non-bagged or low-impurity oily sludge. The conditioning and screening unit includes a heating feeding tank and a conditioning feeding tank. Both tanks are equipped with steam coils, and low-pressure steam of 0.2-0.4 MPa is introduced into the steam coils to heat the pretreated oily sludge. Temperature sensors are installed in the heating feeding tank and the conditioning feeding tank. The PLC control system is connected to the temperature sensors and the steam supply device. When the temperature of the pretreated oily sludge in the two tanks is below 15°C, the steam coils are turned on for heating, and when the temperature reaches 20°C, the steam coils are turned off.

3. The oily sludge treatment device according to claim 2, characterized in that, The oil skimming structure includes an adjustable angle scraper and a scraper drive motor. The output end of the scraper drive motor is connected to the adjustable angle scraper through a transmission component, and the angle adjustment range of the adjustable angle scraper is controlled to be between 15° and 45°.

4. The oily sludge treatment device according to claim 1, characterized in that, The solid-liquid separation unit includes a conditioning and feeding tank and a vertical scraper centrifuge; The conditioning and feeding tank is equipped with an agitator and a time relay. The agitator rotates at a speed of 50-60 r / min. The outlet of the conditioning and feeding tank is connected to a centrifugal pump via a pipe. The flow rate of the centrifugal pump is 10-15 m³ / h. The outlet of the centrifugal pump is connected to the inlet of the vertical scraper centrifuge. The vertical scraper centrifuge includes a drum, a scraper system, and a three-phase outlet. The drum is connected to a drum drive motor via a drive shaft, which provides power to rotate the drum. The drum's base speed is set to 3000 r / min, with a deviation threshold of ±50 r / min. When the oil content of the sludge is <45%, the drum speed is increased; when the oil content of the sludge is >10%, the drum speed is decreased; when the oil content of the sludge is ≥45% and the oil content of the sludge is ≤10%, the drum's base speed is maintained. The scraper system includes a scraper and a scraper servo drive motor. The scraper is installed inside the drum, and the scraper servo drive motor is installed on the top of the drum. The output end of the scraper servo drive motor extends into the drum and is connected to the scraper through a connecting rod. The angle between the scraper blade and the inner wall of the drum is 15°-20°. The scraper servo drive motor controls the movement trajectory of the scraper through the connecting rod to efficiently scrape away the mud phase accumulated on the inner wall of the drum. The three-phase outlets include an oil phase outlet, a water phase outlet, and a mud phase outlet. The mud phase outlet is located at the center of the bottom of the drum and is used to receive the mud phase material scraped off by the scraper. The oil phase outlet and the water phase outlet are located on the side wall of the drum and are at the same height, which facilitates the separation of light oil phase and heavy water phase according to density difference. The three outlets are connected to the sludge buffer tank, the solid waste tank, and the classified sludge storage tank through pipelines, respectively.

5. The oily sludge treatment device according to claim 4, characterized in that, The data acquisition device includes an electromagnetic flow meter, a temperature sensor, a stirring speed sensor, a drum speed sensor, a liquid level sensor, an oil-water interface meter, an online oil content detector, a water content detector, and a turbidity meter, which are used to collect process parameters. The temperature sensor is installed in the conditioning and screening unit of the raw material storage unit and in each processing tank of the equipment unit. The electromagnetic flow meter is installed between the outlet of the conditioning feed tank and the centrifugal pump. The stirring speed sensor is installed in the conditioning feed tank. The drum speed sensor is installed at the drum drive motor. The liquid level sensor is installed in each processing tank of the equipment unit. The oil-water interface meter is installed in the area connecting the oil phase outlet and the water phase outlet. The online oil content detector is installed in the oil phase outlet pipe, the water phase outlet pipe and the solid-liquid separation unit outlet, respectively. The water content detector is installed in the solid-liquid separation unit outlet. The execution module includes a centrifugal pump frequency converter, a drum drive motor frequency converter, an oil phase outlet electric valve, a water phase outlet electric valve, and a scraper servo drive motor.

6. The oily sludge treatment device according to claim 5, characterized in that, The oil phase outlet is equipped with an electric oil phase valve, which is linked to the online oil content detector at the oil phase outlet. The oil phase electric valve is activated when the oil content of the wastewater is ≥45%, and closed when the oil content is <45%, and the drum speed is increased. The water phase outlet is equipped with a water phase electric valve, which is linked to the online oil content detector on the water phase outlet pipeline. The water phase electric valve is activated when the oil content of the wastewater is ≤10%, and closed when the oil content of the wastewater is >10%, and the drum speed is reduced. The scraper servo drive motor is linked to the moisture content detector and oil content detector at the outlet of the solid-liquid separation unit. When the moisture content of the tailings is ≤38% and the oil content of the tailings is ≤1.8%, the scraper starts scraping sludge in the order of upper layer, middle layer and lower layer at 30-second intervals, with a scraping interval of 2 minutes / time. The PLC control system connects the oil-water interface meter, the online oil content detector, and the oil scraper drive motor. When the oil layer thickness is <10mm and the viscosity is <30mPa·s, the adjustable angle oil scraper rotates 45°; when the oil layer thickness is 10-15mm and the viscosity is 30-50mPa·s, the adjustable angle oil scraper rotates 30°; when the oil layer thickness is ≥15mm or the viscosity is ≥50mPa·s, the adjustable angle oil scraper rotates 15°.

7. The oily sludge treatment device according to claim 1, characterized in that, The dosing device adds bio-based agents at a dosage of 0.5%-1.5% of the mass of the oil sludge suspension. The micro-nano bubble generator is linked to the dosing device through an oil-water interface sensor. After demulsification, the thickness of the floating oil layer is confirmed by the oil-water interface instrument, and the floating oil scraping structure is activated based on the thickness of the floating oil layer.

8. A method for treating oily sludge based on the apparatus described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1, Pretreatment: The oily sludge is first processed in the sludge pretreatment unit and then homogenized. Step 2, Water washing and oil separation: The homogenized fluidized sludge is pumped into the water washing and oil separation tank of the water washing and oil separation unit. Bio-based agents are added to the water washing and separation tank, stirred and allowed to stand and separate into layers. When the thickness of the floating oil layer is greater than the preset thickness, the floating oil separation operation is performed. The sludge, oil sludge and mud water discharged after floating oil separation are stored in the first temporary storage unit respectively. The separated oil sludge and mud water are transported to the solid-liquid separation unit. Step 3, Solid-liquid separation: Under the action of centrifugal force, the mud and water and the oil sludge in the solid-liquid separation unit are separated into solid and liquid, resulting in wastewater and tailings. Step 4, Sewage and oil purification: The separated sewage and oil are separated by centrifugation. The speed of the vertical scraper centrifuge is adjusted according to the oil content. Wastewater generated during the purification process is transported to the wastewater treatment unit. Step 5, Wastewater Treatment: The wastewater first undergoes pretreatment, and then sequentially undergoes chemical dosing and stirring, coagulation and sedimentation, dissolved air flotation and three-stage filtration. The resulting greywater is recycled for the separation of sludge and oil in oily sludge. Step 6, Residue Disposal: The tailings are utilized for resource recovery or treated to render them harmless.

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