Equipment and process for pretreating desalted sewage in petrochemical industry

Abstract

The invention relates to the technical field of sewage treatment, and discloses desalted sewage pretreatment equipment and a desalted sewage pretreatment process for petrochemical engineering, and the desalted sewage pretreatment equipment for petrochemical engineering comprises a main machine, a base arranged at the top of the main machine, a top cover arranged at the top of the base, and a separation mechanism arranged in the top cover, the cleaning mechanism is arranged in the top cover and is used for scraping dirt; the separating mechanism comprises a liquid discharging unit arranged in the top cover, a connecting pipe arranged at the bottom of the liquid discharging unit, a flow channel formed by communicating the interior and the exterior of the connecting pipe and connected with the interior and the exterior, and guide rails symmetrically arranged on the two sides of the connecting pipe; the discs are arranged on the outer side of the connecting pipe in a linear array mode and drive sewage to rotate to generate centrifugal force. By arranging the separating mechanism, the distance between the discs can be adjusted to adapt to different kinds of sewage, and the separating mechanism can be matched with the cleaning mechanism to clean the discs.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a post-desalting sewage pretreatment device and process for petrochemical industry. Background Art

[0002] The desalted wastewater produced in the petrochemical production process contains impurities such as suspended matter and oil droplets, and needs to be pre-treated by a blade separator to meet the requirements of subsequent treatment. Its working principle is to use the centrifugal force generated by high-speed rotation to make the solid particles and oil droplets in the wastewater quickly settle to the inner wall of the drum to form a sediment layer, while the clean water is discharged from the overflow port. The spiral pusher continuously discharges the sediment to achieve solid-liquid separation.

[0003] Traditional separators are widely used in the field of environmental protection engineering, but due to the limitations of their structure and working principle, there are often some problems that cannot be ignored. First, the disc spacing of traditional separators is fixed. This design is insufficient when facing sewage containing impurities of different sizes. The fixed-spacing discs cannot be flexibly adjusted to adapt to the distribution of impurity sizes in sewage, resulting in small-sized impurities that may not be effectively intercepted, while large-sized impurities may clog the disc gap, thereby affecting the separation effect and equipment operation efficiency. This fixed design is difficult to achieve optimal separation performance when facing complex and changeable sewage components.

[0004] Secondly, traditional separators often lack special cleaning parts, and the discs are prone to accumulate dirt. Dirt and impurities will gradually settle on the surface of the discs, eventually affecting the separation efficiency of the discs, making the cleaning work extremely cumbersome. Operators need to frequently dismantle the equipment and manually clean the discs, which is not only time-consuming and labor-intensive, but also increases equipment maintenance costs and downtime, which in turn affects the continuity and stability of the entire sewage treatment system. Summary of the invention

[0005] In view of the problems of the prior art that the separator structure is fixed and cannot adapt to the treatment needs of sewage containing impurities of different sizes, and lacks special cleaning components, the dirt cleaning is cumbersome, thus a post-desalting sewage pretreatment equipment for petrochemical industry is proposed.

[0006] The purpose is to enable the separator to adapt to the treatment of different sewage by adjusting the disc spacing and to clean the dirt accumulated on the disc.

[0007] The technical solution of the present invention is a post-desalination wastewater pretreatment device for petrochemical industry, comprising a main machine, a base arranged on the top of the main machine, a top cover arranged on the top of the base, a separation mechanism arranged inside the top cover, and a cleaning mechanism arranged inside the top cover for scraping off dirt; The separation mechanism includes a drainage unit arranged inside the top cover, and the clear liquid and oily dirt after sewage separation are discharged from the drainage unit, a connecting pipe arranged at the bottom of the drainage unit, the inside and the outside of the connecting pipe are connected to form a flow channel connecting the inside and the outside, guide rails symmetrically arranged on both sides of the connecting pipe, a plurality of discs arranged in a linear array on the outside of the connecting pipe, the discs drive the sewage to rotate to generate centrifugal force, two reeds symmetrically arranged on the top of the discs, the top and bottom of the reeds are respectively fixedly connected to two adjacent discs, and an adjustment unit is arranged near the top of the uppermost disc of the connecting pipe.

[0008] Furthermore, the outer annular array of the connecting pipe is provided with four open holes, and the top center of the disc is provided with a restraining hole.

[0009] Furthermore, the drainage unit includes a sewage pipe arranged on the top of the top cover, a clear liquid pipe arranged inside the sewage pipe, and a water inlet pipe arranged inside the clear liquid pipe.

[0010] Furthermore, the regulating unit includes a cover shell arranged at the bottom of the clear liquid pipe, a worm gear arranged inside the cover shell, a worm arranged at the top of the worm gear, and two cams symmetrically arranged on both sides of the worm gear, and the bottom of the cam abuts against the top of the disc at the top of the connecting pipe.

[0011] Furthermore, a knob is provided at the rear end of the worm, and a connecting shaft is provided at the side of the cam close to the worm wheel.

[0012] Furthermore, the cleaning mechanism includes a slide rail arranged on the inner wall of the top cover, a plurality of sliders arranged in a linear array inside the slide rail, a limiting ring arranged at the bottom of the disc, a movable block arranged on the side of the slider away from the slide rail, a rotating shaft arranged on the top of the movable block, a scraper arranged at one end of the rotating shaft close to the disc, two pulleys arranged at the end of the rotating shaft away from the movable block, and a round belt arranged on the outside of the pulley, and the pulleys on two adjacent rotating shafts are connected by the round belt.

[0013] Furthermore, an axial hole is opened on the top of the movable block, and the inner side of the axial hole is slidably connected to the outer wall of the connecting pipe, and limit plates are symmetrically provided at positions of the rotating shaft near both sides of the axial hole.

[0014] Furthermore, a control button is provided at the bottom end of the rotating shaft at the bottom of the cleaning mechanism, and a long groove is provided on the side of the slide rail close to the disc.

[0015] Another object of the present invention is to provide a process for pre-treatment of wastewater after desalination for petrochemical industry, the purpose of which is to separate solid impurities in wastewater and purify the water body.

[0016] To achieve the above object, the present invention provides the following technical solution: a process for pretreatment of desalted wastewater for petrochemical industry, comprising the following steps: First, start the equipment and inject sewage into the equipment through the water inlet pipe; Then, after the sewage enters the equipment, it is driven by the separation mechanism to rotate. The centrifugal force generated by the rotation causes the impurities in the sewage to be thrown to the position near the inner wall of the top cover for enrichment. The sewage impurities near the disc position are separated to form clear liquid; Finally, the wastewater enriched with impurities is discharged through the sewage pipe, and the clear liquid is discharged through the clear liquid pipe.

[0017] Furthermore, when sewage containing impurities of different particle sizes needs to be treated, the spacing between the discs in the separation mechanism can be adjusted to meet different treatment requirements.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting up a separation mechanism, the spacing between discs can be adjusted, so that when the separator faces sewage containing impurities of different sizes, the disc gap can be flexibly adjusted to adapt to the size distribution of impurities. By changing the disc spacing, the separator can more effectively intercept target impurities and avoid the escape of small-sized impurities or blockage by large-sized impurities. This adjustable disc spacing design enhances the versatility and applicability of the separator, enabling it to handle a wider range of sewage types and meet the needs of different sewage treatment scenarios. At the same time, it also helps to optimize the separation efficiency, extend the service life of the equipment, and reduce the maintenance frequency, thereby improving the overall efficiency and economy of sewage treatment.

[0019] 2. By setting up a cleaning mechanism, the disc can be cleaned to prevent long-term accumulation of dirt on the disc surface. Through the operation of the cleaning mechanism, the disc can be kept clean, ensuring that the separator is always in an efficient operating state, reducing the decrease in separation efficiency caused by dirt accumulation, avoiding frequent disassembly and cleaning work, thereby reducing the frequency and cost of equipment maintenance.

[0020] 3. By setting a scraper, the scraper can be turned to different angles to turn the cleaning function on and off. When the disc does not need to be cleaned, the scraper can be adjusted to a position where it does not contact the disc, thereby avoiding continuous friction between the scraper and the disc and reducing wear. When cleaning is required, the scraper is rotated to a specific angle, contacts the disc and performs effective cleaning, which not only ensures that the cleaning function is enabled on demand, but also reduces the wear between the scraper and the disc, thereby extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the sewage pretreatment equipment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the top cover of the sewage pretreatment equipment of the present invention; Figure 3An exploded view of the sewage pretreatment equipment of the present invention; Figure 4 It is a schematic diagram of the disc structure of the sewage pretreatment equipment of the present invention; Figure 5 It is a schematic diagram of the connection between the reed and the disc of the sewage pretreatment equipment of the present invention; Figure 6 It is a schematic diagram of the connecting pipe structure of the sewage pretreatment equipment of the present invention; Figure 7 It is a schematic diagram of the structure of the drainage unit of the sewage pretreatment equipment of the present invention; Figure 8 It is a schematic diagram of the cam structure of the sewage pretreatment equipment of the present invention; Fig. 9 It is a schematic diagram of the connection between the connecting pipe and the clear liquid pipe of the sewage pretreatment equipment of the present invention; Fig.10 It is a schematic diagram of the connection between the pulley and the round belt of the sewage pretreatment equipment of the present invention; Fig.11 It is a schematic diagram of the connection between the slider and the slide rail of the sewage pretreatment equipment of the present invention; Fig.12 It is a schematic diagram of the connection between the movable block and the limit ring of the sewage pretreatment equipment of the present invention; Fig.13 This is a schematic diagram of the connection between the rotating shaft and the scraper of the sewage pretreatment equipment of the present invention.

[0022] In the figure: 1. Main unit; 2. Base; 3. Top cover; 4. Separation mechanism; 5. Cleaning mechanism; 41. Connecting pipe; 42. Guide rail; 43. Disc; 44. Reed; 45. Drain pipe; 46. Cleaning pipe; 47. Water inlet pipe; 48. Cover; 49. Worm gear; 410. Worm; 411. Cam; 51. Slide rail; 52. Sliding block; 53. Limiting ring; 54. Movable block; 55. Rotating shaft; 56. Scraper; 57. Pulley; 58. Round belt. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0024] Example 1, reference Figure 1-Figure 13, which is the first embodiment of the present invention, provides a post-desalination wastewater pretreatment device for petrochemical industry, including a main unit 1, a base 2 fixedly connected to the top of the main unit 1, a top cover 3 fixedly connected to the top of the base 2, a separation mechanism 4 installed inside the top cover 3, and a cleaning mechanism 5 installed inside the top cover 3 for scraping dirt; the separation mechanism 4 includes a drainage unit assembled inside the top cover 3, and the clear liquid and oily dirt after the wastewater separation are discharged from the drainage unit, a connecting pipe 41 rotatably connected to the bottom of the drainage unit, the inside and the outside of the connecting pipe 41 are connected to form a flow channel connected inside and outside, a guide rail 42 symmetrically fixedly connected to both sides of the connecting pipe 41, a plurality of linear arrays of discs 43 slidably connected to the outside of the connecting pipe 41, the disc 43 drives the wastewater to rotate to generate centrifugal force, two reeds 44 symmetrically fixedly connected to the top of the disc 43, the top and bottom of the reed 44 are respectively fixedly connected to two adjacent discs 43, and an adjustment unit assembled on the top of the disc 43 near the top of the connecting pipe 41.

[0025] Specifically, the rotating component inside the base 2 can drive the disc 43 to rotate, the connecting pipe 41 can rotate with the disc 43, the guide rail 42 can constrain the movement direction of the disc 43 outside the connecting pipe 41, the disc 43 can rotate to rotate the sewage, and the sewage can flow to the inside of the connecting pipe 41 in the intervals between different discs 43, the reed 44 can connect two adjacent discs 43, and can use its own elastic force to move the two discs 43 in a direction away from each other, the separation mechanism 4 can adjust the spacing between the discs 43, so that when the separator faces sewage containing impurities of different sizes, it can flexibly adjust the gap between the discs 43 to adapt to the size distribution of the impurities. By changing the spacing between the discs 43, the separator can more effectively intercept the target impurities and avoid the escape of small-sized impurities or the blockage of large-sized impurities. This adjustable disc 43 spacing design enhances the versatility and applicability of the separator, enabling it to process a wider range of sewage types and meet the needs of different sewage treatment scenarios.

[0026] Reference Figure 4-Figure 6 The outer annular array of the connecting pipe 41 has four open holes, and the top center of the disc 43 has a restraining hole.

[0027] Specifically, the clear liquid after impurities are separated enters the interior of the connecting tube 41 through the gaps between different discs 43 and the open holes, and enters the clear liquid pipe 46 through the connecting tube 41. The disc 43 is connected to the connecting tube 41 through the constraint hole so that it can only move along the axis of the connecting tube 41.

[0028] Reference Figure 7 The drainage unit includes a sewage pipe 45 fixedly connected to the top of the top cover 3 , a clear liquid pipe 46 fixedly connected to the inside of the sewage pipe 45 , and a water inlet pipe 47 fixedly connected to the inside of the clear liquid pipe 46 .

[0029] Specifically, the separated impurities and oil will be discharged through the sewage pipe 45, the clear liquid will also be discharged after passing through the clear liquid pipe 46, and the sewage to be treated will be injected into the interior of the equipment through the water inlet pipe 47.

[0030] Reference Figure 7 and Figure 8 The regulating unit includes a cover 48 fixedly connected to the bottom of the clear liquid pipe 46, a worm gear 49 rotatably connected to the inside of the cover 48, a worm 410 meshingly connected to the top of the worm gear 49, and two cams 411 symmetrically fixedly connected to both sides of the worm gear 49, and the bottom of the cam 411 abuts against the top of the disc 43 at the top of the connecting pipe 41.

[0031] Specifically, the cover 48 can provide protection for the moving parts of the adjustment unit. The worm gear 49 can be rotated by rotating the worm 410, and the worm gear 49 drives the cam 411 to rotate. The rotation of the cam 411 will push the disc 43 in contact with it to move up and down, thereby adjusting the spacing between the discs 43.

[0032] Reference Figure 8 A knob is provided at the rear end of the worm 410 , and a connecting shaft is provided at the side of the cam 411 close to the worm wheel 49 .

[0033] Specifically, the worm 410 can be rotated by turning the knob, and the force of the rotation of the worm wheel 49 is transmitted to the cam 411 through the connecting shaft.

[0034] Example 2, reference Figure 10-13 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that: the cleaning mechanism 5 includes a slide rail 51 fixedly connected to the inner wall of the top cover 3, a plurality of sliders 52 slidably connected to the inside of the slide rail 51 in a linear array, a limit ring 53 fixedly connected to the bottom of the disc 43, a movable block 54 fixedly connected to the side of the slider 52 away from the slide rail 51, a rotating shaft 55 rotatably connected to the top of the movable block 54, a scraper 56 fixedly connected to one end of the rotating shaft 55 close to the disc 43, two pulleys 57 fixedly connected to the end of the rotating shaft 55 away from the movable block 54, and a round belt 58 sleeved on the outside of the pulley 57, and the pulleys 57 on two adjacent rotating shafts 55 are connected by the round belt 58.

[0035] The movable block 54 drives the rotating shaft 55 and the corresponding disc 43 to move synchronously. The rotating shaft 55 drives the scraper 56 to rotate together when rotating. After the scraper 56 rotates a certain angle, the edge will contact the top of the corresponding disc 43. After the two produce relative movement, the scraper 56 will scrape off the dirt attached to the disc 43. The pulley 57 can drive the rotating shaft 55 to rotate synchronously. The round belt 58 connects the pulleys 57 on the adjacent rotating shafts 55, so that all the rotating shafts 55 and the scraper 56 move synchronously. By setting the cleaning mechanism 5, the disc 43 can be cleaned to prevent the long-term accumulation of dirt on the surface of the disc 43. Through the operation of the cleaning mechanism 5, the disc 43 can be kept clean, ensuring that the separator is always in an efficient operating state, reducing the reduction in separation efficiency due to dirt accumulation, and avoiding frequent disassembly and cleaning work.

[0036] Reference Fig.10 An axial hole is formed at the top of the movable block 54, and the inner side of the axial hole is slidably connected to the outer wall of the connecting tube 41. Limiting plates are symmetrically provided at positions of the rotating shaft 55 near both sides of the axial hole.

[0037] Specifically, the movable block 54 is connected to the rotating shaft 55 through the shaft hole, and the limiting plate of the rotating shaft 55 will keep the relative position between the rotating shaft 55 and the movable block 54 unchanged.

[0038] Reference Figure 10-13 A control button is provided at the bottom end of the rotating shaft 55 at the bottom of the cleaning mechanism 5, and a long groove is provided on one side of the slide rail 51 close to the disc 43.

[0039] Specifically, by rotating the control knob, the bottommost rotating shaft 55 can be driven to rotate, thereby controlling all the rotating shafts 55 and the scraper 56. The slider 52 fits inside the long groove of the slide rail 51, and the remaining structure is the same as that of Example 1.

[0040] In summary, the working principle of the present invention is as follows: after starting the device, the disc 43 will rotate under the action of the rotating part of the base 2. After the sewage enters the bottom of the disc 43 through the water inlet pipe 47, it flows toward the inner wall of the base 2. During the flow, it is stirred by the disc 43 to generate a vortex. Impurities in the sewage are thrown toward the inner wall of the base 2 under the action of the centrifugal force of the vortex, and are discharged through the gap between the sewage discharge pipe 45 and the clear liquid pipe 46. The separated clear liquid enters the connecting pipe 41 through the gap between the discs 43, and is then discharged through the clear liquid pipe 46. Before treating sewage, the gaps between different discs 43 can be adjusted to adapt to the impurities carried in the sewage. The worm 410 and the worm wheel 49 are driven to rotate the cam 411 by turning the knob. When the distal end of the cam 411 contacts the disc 43 at the bottom, it will press the uppermost disc 43 downward. Different discs 43 are connected by reeds 44, so the pressure of the cam 411 will be dispersed to all reeds 44, so that the spacings of all discs 43 are synchronously reduced. When the proximal end of the cam 411 contacts the uppermost disc 43, different discs 43 will move away from each other under the action of the reeds 44, so that the distances between all discs 43 are expanded at the same time. By controlling the rotation of the cam 411, the gaps between different blades can be regulated. When the disc 43 needs to be cleaned, the lowest rotating shaft 55 is rotated through the control button. While the rotating shaft 55 rotates, the other rotating shafts 55 and scrapers 56 are driven to rotate simultaneously through the pulley 57 and the round belt 58. The rotating shaft 55 drives the scraper 56 connected thereto to rotate, so that the edge of the scraper 56 contacts the two adjacent discs 43. When the disc 43 rotates, the scraper 56 will clean the dirt attached to the blades. When the disc 43 is raised or lowered, the movable block 54 is driven to move simultaneously through the limit ring 53. The movable block 54 is constrained by the slider 52 and the slide rail 51, and can move in the vertical direction to adapt to the distance change between the discs 43.

[0041] Example 3, reference Figure 1-Figure 10 , as the third embodiment of the present invention, provides: a process for pretreatment of desalted wastewater for petrochemical industry, comprising the following steps: S1, first, start the device and inject sewage into the device through the water inlet pipe 47. The sewage entering the device will be subjected to the force from the disc 43; S2, after the sewage enters the equipment, it is driven by the separation mechanism 4 to rotate. The centrifugal force generated by the rotation causes the impurities in the sewage to be thrown to the position near the inner wall of the top cover 3 for enrichment. The sewage impurities near the disc 43 are separated to form a clear liquid. By utilizing the difference in mass between different substances, the fixed impurities and oil in the sewage are separated; S3, finally, the sewage enriched with impurities is discharged through the sewage pipe 45, and the clear liquid is discharged through the clear liquid pipe 46, and the separated impurities and clear liquid will be processed in the next treatment process.

[0042] S4, when it is necessary to treat sewage containing impurities of different particle sizes, the spacing between the discs 43 in the separation mechanism 4 can be adjusted to meet different treatment requirements. Different types of sewage can be treated by adjusting the equipment.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A post-desalting wastewater pretreatment device for petrochemical industry, comprising a main unit (1), a base (2) arranged on the top of the main unit (1), and a top cover (3) arranged on the top of the base (2), characterized in that: It also includes a separation mechanism (4) disposed inside the top cover (3), and a cleaning mechanism (5) disposed inside the top cover (3) for scraping off dirt; The separation mechanism (4) comprises a drainage unit arranged inside the top cover (3), the clear liquid and oily dirt after the sewage is separated are discharged from the drainage unit, a connecting pipe (41) arranged at the bottom of the drainage unit, the inside and the outside of the connecting pipe (41) are connected to form a flow channel connecting the inside and the outside, guide rails (42) symmetrically arranged on both sides of the connecting pipe (41), a plurality of discs (43) arranged in a linear array outside the connecting pipe (41), the discs (43) drive the sewage to rotate to generate centrifugal force, two reeds (44) symmetrically arranged on the top of the discs (43), the top and bottom of the reeds (44) are respectively fixedly connected to two adjacent discs (43), and an adjustment unit is arranged on the top of the disc (43) at the top of the connecting pipe (41).

2. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 1, characterized in that: The outer side of the connecting pipe (41) is provided with four open holes in an annular array, and the top center of the disc (43) is provided with a restraining hole.

3. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 1, characterized in that: The liquid discharge unit comprises a sewage discharge pipe (45) arranged on the top of the top cover (3), a liquid cleaning pipe (46) arranged inside the sewage discharge pipe (45), and a water inlet pipe (47) arranged inside the liquid cleaning pipe (46).

4. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 1, characterized in that: The regulating unit comprises a housing (48) arranged at the bottom of the clear liquid pipe (46), a worm wheel (49) arranged inside the housing (48), a worm (410) arranged at the top of the worm wheel (49), and two cams (411) symmetrically arranged on both sides of the worm wheel (49), wherein the bottom of the cam (411) abuts against the top of the disc (43) at the top of the connecting pipe (41).

5. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 4, characterized in that: A knob is provided at the rear end of the worm (410), and a connecting shaft is provided at a side of the cam (411) close to the worm wheel (49).

6. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 1, characterized in that: The cleaning mechanism (5) comprises a slide rail (51) arranged on the inner wall of the top cover (3), a plurality of sliders (52) arranged in a linear array inside the slide rail (51), a limiting ring (53) arranged at the bottom of the disc (43), a movable block (54) arranged on the side of the slider (52) away from the slide rail (51), a rotating shaft (55) arranged on the top of the movable block (54), a scraper (56) arranged at one end of the rotating shaft (55) close to the disc (43), two pulleys (57) arranged at one end of the rotating shaft (55) away from the movable block (54), and a round belt (58) arranged outside the pulleys (57), and the pulleys (57) on two adjacent rotating shafts (55) are connected by the round belt (58).

7. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 6, characterized in that: The top of the movable block (54) is provided with an axial hole, and the inner side of the axial hole is slidably connected to the outer wall of the connecting tube (41). Position limit plates are symmetrically provided near both sides of the axial hole of the rotating shaft (55).

8. The desalinated wastewater pretreatment equipment for petrochemical industry according to claim 1, characterized in that: A control button is provided at the bottom end of the rotating shaft (55) at the bottom of the cleaning mechanism (5), and a long groove is provided on one side of the slide rail (51) close to the disc (43).

9. A process for pretreatment of desalinated wastewater for petrochemical industry, applied to the desalinated wastewater pretreatment equipment for petrochemical industry as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: First, the device is started, and sewage is injected into the device through the water inlet pipe (47); Then, after the sewage enters the device, it is driven by the separation mechanism (4) to rotate. The centrifugal force generated by the rotation causes the impurities in the sewage to be thrown to a position close to the inner wall of the top cover (3) for enrichment. The sewage impurities close to the disc (43) are separated to form clear liquid. Finally, the sewage enriched with impurities is discharged through the sewage pipe (45), and the clear liquid is discharged through the clear liquid pipe (46).

10. The process for pretreatment of desalted wastewater for petrochemical industry according to claim 9, characterized in that: When sewage containing impurities of different particle sizes needs to be treated, the spacing between the discs (43) in the separation mechanism (4) is adjusted to meet different treatment requirements.

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