Fluidized, screened, and co-processed system and method for oily sludge

Abstract

The present application relates to the technical field of oil sludge treatment, and particularly relates to a system and method for fluidizing and screening oil-containing sludge. The system comprises a fluidization zone, a screening zone and a homogenization zone. The fluidization zone is provided with a fluidization stirring shaft, and the fluidization zone contains dilution liquid. The screening zone is located in the fluidization zone, and the screening zone is provided with a screening frame and a grating decontamination machine. The screening frame has a bottom screen plate, the screen holes of the bottom screen plate can pass particles with a maximum aperture of 20 mm, and the bottom screen plate is immersed in the dilution liquid. The screening zone is arranged in the fluidization zone, so that the screening step and the fluidization step can promote each other, which helps to improve the fluidization efficiency and the screening efficiency. Furthermore, the fluidization stirring shaft and the grating decontamination machine are arranged, which improves the adaptability of the fluidization zone to impurity types and volumes, reduces the probability of impurity deposition, and enables the whole system to operate coordinately for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil sludge treatment, in particular to a system and method for fluidizing and screening oil-containing sludge. BACKGROUND

[0002] Oil-containing sludge is a solid / semi-solid compound produced in the production process of the petroleum industry. Due to its toxicity and flammability, oil-containing sludge is listed in the National Hazardous Waste List (2018). Oil-containing sludge often contains mechanical impurities such as bricks, tiles, woven bags, safety supplies, and weeds. In order to remove the impurities in the oil-containing sludge, the oil-containing sludge usually needs to be fluidized first to reduce its viscosity and improve its flowability, and then screened. For example, Chinese patent document CN110606633A discloses a method and system for resource utilization and reduction of oil-containing sludge, which includes a decontamination system and an oil recovery system. The decontamination system includes a crushing step, a fluidization step, and a screening step in sequence. The oil sludge is first crushed into small particles by a crusher and then falls into a fluidization tank. The viscosity of the particles is reduced by heating and stirring in the fluidization tank. Then the mixture in the fluidization tank is pumped to a vibrating screen by a slurry pump for separation. The screened oil sludge enters the oil recovery system to recover oil. The disadvantages of this scheme are: (1) the oil sludge mixed with impurities needs to be crushed into a particle size suitable for slurry pump conveying by a crusher; (2) in the work site, larger particles or impurities are more likely to fall into the fluidization tank, which may block the slurry pump.

[0003] Secondly, Chinese patent document CN217265148U discloses an oil sludge hot cleaning system with a fluidization and screening pretreatment unit, which mainly includes an shaftless screw feeder, a fluidization cylinder, and a double-layer screening net fixed at the tail end of the fluidization cylinder. It integrates feeding, homogeneous fluidization, and screening into one device, improving the processing efficiency of hot cleaning technology for oil sludge. This scheme provides a reference in terms of structure connection, but it does not promote the functions of fluidization and screening. From a functional point of view, it is no different from Chinese patent document CN110606633A. SUMMARY

[0004] The present application aims to overcome the above-mentioned defects in the prior art and provide a system and method for fluidizing and screening oil-containing sludge, which discards the combination of a crusher and a slurry pump, provides a new screening method, promotes screening and fluidization to improve fluidization efficiency and screening efficiency, and reduces the adverse effects of unexpected impurities falling into the fluidization tank on fluidization liquid delivery.

[0005] To achieve the above-mentioned purposes, the technical solutions of the present application are as follows:

[0006] The oil-containing sludge fluidization, screening and synergistic treatment system comprises a fluidization zone, a screening zone and a homogenization zone, and the homogenization zone is communicated with the fluidization zone.

[0007] The fluidization zone is provided with a fluidization stirring device and a fluidization heating device, the fluidization stirring device is a pair of fluidization stirring shafts, and the fluidization zone is provided with dilution liquid.

[0008] The screening zone is located in the fluidization zone, and a screening frame and a grating cleaner are arranged in the screening zone, and the grating cleaner and the fluidization stirring device are respectively located on both sides of the screening frame.

[0009] The screening frame is driven by a vibrating motor, the screening frame is provided with a bottom screen plate, the screen holes of the bottom screen plate can pass particles with a maximum aperture of 20 mm, the bottom screen plate is immersed in the dilution liquid, and the screening frame is provided with a screen overflow outlet for guiding the screen overflow to the grating cleaner.

[0010] The grating cleaner is obliquely arranged so that the lower part of the grating cleaner is located below the screening frame, and the fluidization stirring shafts are opened in pairs so that the liquid below the screening frame flows towards the grating cleaner.

[0011] The inventive concept of the present application is:

[0012] (1) The screening zone is creatively arranged in the fluidization zone, and the bottom of the screening frame is immersed in the dilution liquid so that the oil sludge is partially or entirely immersed in the dilution liquid during screening, and when the screening frame vibrates with the vibrating motor, the large particles in the oil sludge vibrate on the bottom screen plate, which is beneficial to the fluidization of the oil sludge.

[0013] Secondly, the size of the screen holes of the bottom screen plate is limited, the screen holes can pass particles with a maximum aperture of 20 mm, while in existing engineering practices, the screen hole aperture for screening pure liquid oil sludge is generally 5 mm, and the screen hole aperture for screening oil sludge on the ground or relatively thick oil sludge is 10 mm. The present application expands the aperture of the screen holes, so that part of the oil sludge or particles that should be screen overflow becomes screen underflow, thereby improving the separation speed of the screen overflow and the screen underflow. The liquid below the screening frame flows towards the grating cleaner, so that the screen underflow is pushed to the grating cleaner and most of it is taken out of the fluidization zone by the grating cleaner during the dispersion and sinking process. That is, the expansion of the screen hole aperture and the flow of the liquid below the screening frame can improve the screening efficiency.

[0014] (2) The grating cleaner is used to remove particle impurities and the like, the fluidization stirring device is arranged in the fluidization zone, the stirring drives the flow of the liquid in the fluidization zone, so that the particles remaining at the bottom of the fluidization zone can continuously contact the grating cleaner and be taken out of the fluidization zone by the grating cleaner, and a relatively thick accumulation layer will not be formed at the bottom of the fluidization zone.

[0015] (3) The application uses a grid cleaner to remove particulate impurities, and the fluidization zone and the homogenization zone are connected, so that if large particles accidentally fall into the fluidization zone, it will not adversely affect the smooth delivery of the fluidizing liquid compared with the scheme described in Chinese patent document CN 110606633 A.

[0016] As an improvement, the bottom of the grid cleaner extends to the bottom of the fluidization zone, reducing the probability of forming an accumulation layer at the bottom of the fluidization zone.

[0017] As an improvement, the fluidizing stirring shaft has a fluidizing paddle, and the distal end of the fluidizing paddle is raised, so that the fluidizing liquid near the fluidizing stirring shaft is not only subjected to a horizontal force but also an upward force, which can reduce the probability of impurities depositing at the bottom of the fluidization zone, and make the impurities move upward with the fluid and be pushed towards the grid cleaner.

[0018] As an improvement, the screening frame has an angle adjusting mechanism, which can adjust the angle of the screening frame for different types of oil sludge to adjust the screening and dissolution time of the oil sludge.

[0019] As an improvement, the screening frame is fixed on a support, which includes a fixed support and an adjusting support as an angle adjusting mechanism, and the elevation angle of the screening frame is adjusted by adjusting the length of the adjusting support.

[0020] As an improvement, the bottom screen plate adopts a mesh structure or a waist-shaped hole structure.

[0021] The application also provides another oil-containing sludge fluidization and screening collaborative treatment system, which comprises a fluidization zone, a screening zone and a homogenization zone, and the homogenization zone is connected with the fluidization zone.

[0022] The fluidization zone is provided with a fluidizing stirring device and a fluidizing heating device, the fluidizing stirring device is a pair of fluidizing stirring shafts, and the fluidization zone has a dilution liquid;

[0023] The screening zone is located in the fluidization zone, and a screening frame and a grid cleaner are arranged in the screening zone, and the grid cleaner and the fluidizing stirring device are respectively located on both sides of the screening frame.

[0024] The screening frame is driven by a vibrating motor, the screening frame has a bottom screen plate, the bottom screen plate is a grid composed of strips, adjacent strips form a long strip-shaped gap with a spacing of not more than 10 mm, the bottom screen plate is immersed in the dilution liquid, and the screening frame has a screen overflow outlet for guiding the screen overflow to the grid cleaner.

[0025] The grid cleaner is inclinedly arranged so that the lower part of the grid cleaner is located below the screening frame; the fluidizing stirring shafts are opened in pairs so that the liquid below the screening frame flows towards the grid cleaner.

[0026] Different from the previous scheme, the scheme can make gloves, packaging bags and other flexible sundries become undersize, reduce the shielding of the screen hole, and help to further improve the screening efficiency.

[0027] As an improvement, the homogenization zone is located on the side away from the screening zone, and the homogenization zone is provided with a homogenization stirring device and a homogenization liquid guide outlet.

[0028] As an improvement, the homogenization stirring device is provided with double-layer paddles, and the double-layer paddles are horizontally arranged.

[0029] As an improvement, the fluidization zone is also provided with a dilution liquid guide pipeline, the dilution liquid guide pipeline extends into the inside of the fluidization zone and is close to the bottom of the fluidization zone. In the process of fluidization and screening, dilution liquid needs to be continuously introduced. Since the dilution liquid guide pipeline is close to the bottom of the fluidization zone, the dilution liquid can impact the sundries at the bottom of the fluidization zone, so that the sundries are in a suspended state, and then, in cooperation with the fluidization stirring shaft, the sundries can move to the grille cleaner.

[0030] The application also provides a fluidization and screening collaborative treatment method for oily sludge, which comprises a fluidization step, a screening step and a homogenization step.

[0031] S1, the oily sludge is transported into a screening frame immersed in the dilution liquid at the bottom, an oscillation motor drives the screening frame to oscillate, so that the oily sludge is continuously washed by the dilution liquid in the screening process, the screening frame can allow particles with a maximum particle size of 20 mm to pass through, the oversize is guided out of the fluidization zone by the grille cleaner, and the undersize is dispersed and sinks in the dilution liquid.

[0032] S2, the dilution liquid below the screening frame flows towards the grille cleaner, and the undersize that sinks is pushed to the grille cleaner, so that part of the undersize collides with the grille cleaner and is guided out of the fluidization zone by the grille cleaner.

[0033] The application also provides another fluidization and screening collaborative treatment method for oily sludge, which comprises a fluidization step, a screening step and a homogenization step.

[0034] S1, the oily sludge is transported into a screening frame immersed in the dilution liquid at the bottom, an oscillation motor drives the screening frame to oscillate, so that the oily sludge is continuously washed by the dilution liquid in the screening process, the screening frame has a bottom screen plate, the bottom screen plate is a grille composed of strips, adjacent strips form long strip-shaped gaps with a spacing of not more than 10 mm, the oversize is guided out of the fluidization zone by the grille cleaner, and the undersize is dispersed and sinks in the dilution liquid.

[0035] S2, the dilution liquid under the screening frame flows towards the grid cleaner, and the subsidence of the undersize material is pushed towards the grid cleaner, so that part of the undersize material collides with the grid cleaner and is guided out of the fluidization zone.

[0036] As an improvement, the fluidization stirring shafts are arranged in pairs in the fluidization zone, and the pairs of fluidization stirring shafts are started to make the dilution liquid under the screening frame flow towards the grid cleaner.

[0037] As an improvement, the bottom of the grid cleaner extends to the bottom of the fluidization zone.

[0038] In summary, the present application sets the screening zone in the fluidization zone, so that the screening step and the fluidization step can promote each other, which helps to improve the fluidization efficiency and the screening efficiency, and through the arrangement of the fluidization stirring shafts and the grid cleaner, the adaptability of the fluidization zone to the types and volumes of impurities is improved, the probability of impurity deposition is reduced, and the whole system can run coordinately for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the embodiment 1 of the present application;

[0040] Figure 2 It is a structural schematic diagram of the angle adjusting mechanism of the embodiment 1 of the present application;

[0041] Figure 3 It is a structural schematic diagram of the bottom sieve plate in the embodiment 1 of the present application;

[0042] Figure 4 It is a structural schematic diagram of the embodiment 2 of the present application;

[0043] Figure 5 It is a structural schematic diagram of the bottom sieve plate in the embodiment 2 of the present application.

[0044] In the figure: 10, fluidization zone; 11, fluidization stirring device; 111, fluidization paddle; 12, fluidization heating device; 13, dilution liquid introduction pipeline; 20, screening zone; 21, screening frame; 22, support; 221, fixed support; 222, adjusting support; 23, bottom sieve plate; 24, side sieve plate; 25, oversize material outlet; 26, grid cleaner; 30, homogenization zone; 31, homogenization stirring device; 32, homogenization liquid guide outlet. DETAILED DESCRIPTION

[0045] Embodiment 1

[0046] As shown in Figure 1 , Figure 2 and Figure 3 , the oil-containing sludge fluidization and screening collaborative treatment system of the present application comprises a fluidization zone 10, a screening zone 20 located in the fluidization zone, and a homogenization zone 30 communicating with the fluidization zone.

[0047] Fluidization stirring device 11 and fluidization heating device 12 are arranged in fluidization zone 10. Fluidization stirring device 11 is a pair of fluidization stirring shafts with fluidization paddles 111 on the distal end of which are raised. Fluidization heating device 12 is a heating coil. Dilution liquid inlet pipe 13 is arranged in fluidization zone 10 and extends into the interior of fluidization zone 10 and is close to the bottom of fluidization zone 10.

[0048] Screening frame 21 is arranged in screening zone 20. Screening frame 21 is fixed on support 22, which includes fixed support 221 and adjusting support 222 as an angle adjusting mechanism. The angle of screening frame 21 is adjusted by adjusting the length of adjusting support 222. Screening frame 21 has bottom screen 23 and side screen 24, which form a frame shape to accommodate the sludge to be treated. Screening frame 21 is provided with screen overflow outlet 25 on the side opposite to bar screen 26, through which the screen overflow reaches bar screen 26. Fluidization stirring device 11 is arranged on one side of screening frame 21, and bar screen 26 is arranged on the other side of screening frame 21. The bottom of bar screen 26 extends to the bottom of fluidization zone 10.

[0049] Homogenization zone 30 is arranged on the side away from screening zone 20, and homogenization stirring device 31 and homogenization liquid outlet 32 are arranged in homogenization zone 30. Homogenization stirring device 31 is provided with double-layer paddles arranged horizontally.

[0050] The application of the present application is as follows:

[0051] Before the treatment of the oily sludge, the dilution liquid was introduced into the fluidization zone 10, so that the volume of the dilution liquid accounted for 80% of the volume of the fluidization zone 10. The dilution liquid was water. Then the fluidization heating device 12 was started to heat the dilution liquid to 80℃. After that, the fluidization and screening process of the oily sludge was carried out. The oily sludge was fresh oily sludge generated from the production operation of an oil field. The moisture content of the oily sludge was 26%, the solid content was 62%, and the oil content was 9%. The oily sludge entered the bottom screen plate 23 for screening and fluidization. In this embodiment, the screening frame 21 was parallel to the horizontal plane. The screening frame 21 was driven by a vibrating motor, and the vibration frequency was 8HZ and the amplitude was 5mm. The side screen plate was provided with a mesh, and the mesh had a pore size of 10mm. The bottom screen plate 23 was provided with a mesh structure, and the mesh had a pore size of 20mm. The bottom screen plate 23 was immersed in the dilution liquid, so that the dilution liquid could soak the oily sludge. During screening, the fluidization stirring device 11 was started at the same time, and the stirring frequency of the fluidization stirring device 11 was 80r / min. In this embodiment, the length of the fluidization stirring shaft was set to 4 / 5 of the height of the fluidization zone 10. The oversize passed through the oversize outlet 25 into the grid cleaner 26, and the undersize flowed to the grid cleaner 26 under the drive of the fluidization stirring shaft. After fluidization, the oily sludge entered the homogenization zone 30 for homogenization. Compared with the previous screen hole size, the falling speed of the oily sludge from the bottom screen plate 23 was significantly improved, there was no obvious deposition at the bottom of the fluidization zone 10, and the impurities taken out by the grid cleaner 26 basically did not contain sludge blocks. After running for one month, the system could run continuously and stably.

[0052] Example 2

[0053] As shown in Figure 4 and Figure 5 The difference between this embodiment and example 1 is that:

[0054] For some oily sludge containing more flexible impurities (plastic bags, woven bags, etc.), when the bottom screen plate 23 with a mesh structure is used for screening, the flexible impurities are easy to block the mesh.

[0055] In this embodiment, the bottom screen plate 23 is a grid composed of strips, and the adjacent strips form long strip-shaped gaps with a spacing of not more than 10mm. This form of bottom screen plate can make flexible materials pass through the long strip-shaped gaps. During the falling process of the flexible impurities, the drive of the fluidization stirring shaft makes the flexible impurities move towards the grid cleaner 26. The length of the fluidization stirring shaft is set to 1 / 2 of the height of the fluidization zone.

Claims

1. An oil-containing sludge fluidization and screening collaborative treatment system, comprising a fluidization zone (10), a screening zone (20) and a homogenization zone (30), the homogenization zone (30) being in communication with the fluidization zone (10), characterized in that: the fluidization zone (10) is provided with a fluidization stirring device (11) and a fluidization heating device (12), the fluidization stirring device (11) being a pair of fluidization stirring shafts, and there being dilution liquid in the fluidization zone (10); the screening zone (20) is located in the fluidization zone (10), and the screening zone (20) is provided with a screening frame (21) and a grating cleaner (26), the grating cleaner (26) and the fluidization stirring device (11) being located on the two sides of the screening frame (21) respectively; the screening frame (21) is driven by a vibrating motor, the screening frame (21) has a bottom screen plate (23), the screen holes of the bottom screen plate (23) can allow particles with a maximum aperture of 20 mm to pass through, the bottom screen plate (23) is immersed in the dilution liquid, and the screening frame (21) has an oversize outlet (25) for guiding oversize materials to the grating cleaner; the grating cleaner (26) is obliquely arranged so that the lower part of the grating cleaner (26) is located below the screening frame (21); and the pair of fluidization stirring shafts are opened so that the liquid below the screening frame flows towards the grating cleaner (26). The bottom part of the grating cleaner (26) extends to the bottom part of the fluidization zone (10). The fluidization stirring shafts have fluidization paddles (111), and the distal ends of the fluidization paddles (111) are upwardly inclined. The screening frame (21) has an angle adjusting mechanism. The screening frame (21) is fixed on a support (22), the support (22) comprises a fixed support (221) and an adjusting support (222) as the angle adjusting mechanism, and the angle of the screening frame (21) is adjusted by adjusting the length of the adjusting support (222).

2. The system for fluidization, screening and co-treatment of oil-containing sludge according to claim 1, characterized in that: The bottom screen plate (23) adopts a mesh structure or a waist-shaped hole structure.

3. The system for fluidization, screening and co-treatment of oil-containing sludge according to claim 1, characterized in that: The homogenization zone (30) is located on the side away from the screening zone (20), and the homogenization zone (30) is provided with a homogenization stirring device (31) and a homogenization liquid guide outlet (32).

4. The system for fluidization, screening and co-treatment of oil-containing sludge according to claim 1, characterized in that: The homogenization stirring device (31) is provided with double-layer paddles, and the double-layer paddles are arranged horizontally.

5. The system for fluidization, screening and synergistic treatment of oil-containing sludge according to claim 4, characterized in that: The fluidization zone (10) is further provided with a dilution liquid guide pipeline (13), the dilution liquid guide pipeline (13) extends into the inside of the fluidization zone (10) and is close to the bottom part of the fluidization zone (10).

6. The fluidized, screened, co-processed oil-containing sludge system of claim 1, wherein:

10. An oil-containing sludge fluidization and screening collaborative treatment system, comprising a fluidization zone (10), a screening zone (20) and a homogenization zone (30), the homogenization zone (30) being in communication with the fluidization zone (10), characterized in that: the fluidization zone (10) is provided with a fluidization stirring device (11) and a fluidization heating device (12), the fluidization stirring device (11) being a pair of fluidization stirring shafts, and there being dilution liquid in the fluidization zone (10); the screening zone (20) is located in the fluidization zone (10), and the screening zone (20) is provided with a screening frame (21) and a grating cleaner (26), the grating cleaner (26) and the fluidization stirring device (11) being located on the two sides of the screening frame (21) respectively; 7. The system for fluidization, screening and co-treatment of oil-containing sludge according to claim 1, characterized in that: ​ 8. The system for fluidization, screening and co-treatment of oil-containing sludge according to claim 7, characterized in that: ​ 9. The fluidized, screened, co-processed oil-containing sludge system of claim 1, wherein: ​ ​ ​ ​ The screening frame (21) is driven by a vibration motor, the screening frame (21) has a bottom screen plate (23), the bottom screen plate (23) is a grid composed of strips, long strip-shaped gaps with a spacing of no more than 10 mm are formed between adjacent strips, the bottom screen plate (23) is immersed in the dilution liquid, the screening frame (21) has a oversize outlet (25) for guiding the oversize to the grid cleaner (26); The grid cleaner (26) is arranged obliquely so that the lower part of the grid cleaner (26) is located below the screening frame (21); the fluidized stirring shafts are opened in pairs so that the liquid below the screening frame (21) flows towards the grid cleaner (26).

11. The system for fluidization, screening and synergistic treatment of oil-containing sludge according to claim 10, characterized in that: The homogenization zone (30) is located on the side away from the screening zone (20), and the homogenization zone (30) is provided with a homogenization stirring device (31) and a homogenization liquid guide outlet (32).

12. The fluidized, screened, co-processed oil-containing sludge system of claim 11, wherein: The homogenization stirring device (31) is provided with double-layer paddles arranged horizontally.

13. The fluidized, screened, co-processed oil-containing sludge system of claim 10, wherein: The fluidization zone (10) is further provided with a dilution liquid guide pipeline (13) extending into the inside of the fluidization zone (10) and close to the bottom of the fluidization zone (10).

14. A method for fluidizing, screening and synergistically treating oily sludge, comprising a fluidizing step, a screening step and a homogenizing step, the fluidizing step being performed in a fluidizing zone, the fluidizing zone having a dilution liquid, the homogenizing step being performed in a homogenizing zone, the homogenizing zone having a homogenizing liquid outlet, characterized in that: The fluidization step and the screening step are: S1, the oil-containing sludge is transported into the screening frame immersed in the dilution liquid at the bottom, the screening frame is driven to vibrate by the vibration motor, so that the oil-containing sludge is continuously washed by the dilution liquid during the screening process, the screening frame can pass particles with a maximum aperture of 20 mm, and the oversize is guided out of the fluidization zone by the grid cleaner, and the undersize is dispersed and sinks in the dilution liquid; S2, the dilution liquid below the screening frame flows towards the grid cleaner, and the sinking undersize is pushed to the grid cleaner, so that part of the undersize collides with the grid cleaner and is guided out of the fluidization zone by the grid cleaner.

15. The method of fluidization, screening and co-treatment of oil-containing sludge according to claim 14, characterized in that: The fluidization zone is provided with fluidized stirring shafts in pairs, and the fluidized stirring shafts are started in pairs so that the dilution liquid below the screening frame flows towards the grid cleaner.

16. The method of fluidization, screening and co-treatment of oil-containing sludge according to claim 14, characterized in that: The bottom of the grid cleaner extends to the bottom of the fluidization zone.

17. A method for the fluidization, screening and synergic treatment of oily sludge, comprising a fluidization step, a screening step and a homogenization step, the fluidization step being carried out in a fluidization zone, in which a dilution liquid is present, the homogenization step being carried out in a homogenization zone, characterized in that: The fluidization step and the screening step are: S1, the oil-containing sludge is transported into the screening frame immersed in the dilution liquid at the bottom, the screening frame is driven to vibrate by the vibration motor, so that the oil-containing sludge is continuously washed by the dilution liquid during the screening process, the screening frame has a bottom screen plate, the bottom screen plate is a grid composed of strips, long strip-shaped gaps with a spacing of no more than 10 mm are formed between adjacent strips, the oversize is guided out of the fluidization zone by the grid cleaner, and the undersize is dispersed and sinks in the dilution liquid; S2, the dilution liquid below the screening frame flows towards the grid cleaner, and the sinking undersize is pushed to the grid cleaner, so that part of the undersize collides with the grid cleaner and is guided out of the fluidization zone by the grid cleaner.

18. The method of fluidization, screening and co-treatment of oil-containing sludge according to claim 17, characterized in that: The fluidization zone is provided with fluidized stirring shafts in pairs, and the fluidized stirring shafts are started in pairs so that the dilution liquid below the screening frame flows towards the grid cleaner.

19. The method of fluidization, screening and co-treatment of oil-containing sludge according to claim 17, characterized in that: The bottom of the grid cleaner extends to the bottom of the fluidization zone.

Images