Urban sewage treatment system

Abstract

The invention discloses an urban sewage treatment system which comprises a water inlet channel, a pretreatment mechanism, a primary sedimentation ditch, a grease adsorption mechanism, an oxidation ditch and a secondary sedimentation ditch, the water inlet channel is communicated with the primary sedimentation ditch, the pretreatment mechanism is arranged in the water inlet channel, most solid impurities in sewage are removed through the pretreatment mechanism, and the grease adsorption mechanism is arranged in the oxidation ditch. A grease adsorption mechanism is arranged in the primary precipitation ditch, is communicated with the oxidation ditch at the tail part of the primary precipitation ditch, and is communicated with the secondary precipitation ditch after oxidation; grease in sewage can be conveniently cleared away before biochemical treatment, so that the aeration time of subsequent biochemical treatment is shortened, and the sewage treatment efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of environmentally friendly sewage treatment equipment, and in particular to an urban sewage treatment system. Background Art

[0002] At present, urban sewage treatment is mainly transported to the sewage treatment plant through pipelines and enters the pretreatment process of the sewage treatment plant. The solid impurities are removed through the coarse and fine fences of the pretreatment. However, a small amount of sand mixed with sewage enters the next process. After the sand and sewage enter the aeration sedimentation tank, aeration is used to separate the organic matter and grease on the surface of the sand. The grease and suspended matter floating on the surface of the aeration sedimentation tank are scraped off by the scraper. The sewage enters the oxidation ditch, and is biochemically treated by aeration and sludge containing microorganisms. Then it enters the sedimentation tank to separate the sludge from the water. The treated water can be treated again or directly used as urban water (irrigation and road cleaning).

[0003] The aerated grit tank for sewage pretreatment cleans and separates the grit through aeration, and scrapes off the suspended grease. However, due to the aeration stage, the sewage is violently churned, so there is still a lot of grease in the water. Since the grease will affect the subsequent microbial treatment of sewage, thus affecting the effect of subsequent biochemical treatment, the aeration time will be increased, resulting in a decrease in the sewage treatment rate. At the same time, after the aeration is completed, it is still necessary to remove the grease through a long period of sedimentation to prevent the grease from entering the activated carbon and contaminating it. Summary of the invention

[0004] In view of the above-mentioned deficiencies of the prior art, the present invention proposes an urban sewage treatment system, which is convenient for removing grease from sewage before biochemical treatment, thereby reducing the aeration time of subsequent biochemical treatment and improving the efficiency of sewage treatment.

[0005] To achieve the above-mentioned purpose, the scheme of the present invention is as follows: an urban sewage treatment system, comprising a water inlet channel, a pretreatment mechanism, a primary sedimentation ditch, a grease adsorption mechanism, an oxidation ditch and a secondary sedimentation ditch, wherein the water inlet channel is connected with the primary sedimentation ditch, a pretreatment mechanism is arranged in the water inlet channel, most of the solid impurities in the sewage are removed by the pretreatment mechanism, a grease adsorption mechanism is arranged in the primary sedimentation ditch, the tail of the primary sedimentation ditch is connected with the oxidation ditch, and after oxidation, it is connected with the secondary sedimentation ditch; An aeration assembly is arranged at the bottom of the primary sedimentation ditch, and the bottom of the primary sedimentation ditch is an inclined surface inclined to one side, and a discharging assembly is arranged at the lowest part of the primary sedimentation ditch; the grease adsorption mechanism includes an oil removal plate frame, a conveying assembly and a cleaning assembly, wherein a conveying assembly is arranged in the primary sedimentation ditch, and a plurality of oil removal plate frames are installed on the conveying assembly at equal intervals, and the oil removal plate frames are lifted and lowered by the conveying assembly, and a cleaning assembly is arranged above the primary sedimentation ditch, and the oil removal plate frame is lifted upward and immersed in the cleaning assembly for cleaning, so as to facilitate the next oil absorption.

[0006] Preferably, the conveying assembly includes a conveying chain and a conveying gear. Two groups of front-to-rear mounted columns are arranged on the inner walls on both sides of the primary sedimentation tank. A gear driven by a motor is installed on each column. Multiple conveying gears on the columns on the same side are meshed and transmitted with the same conveying chain. One end of the degreasing plate frame is rotatably connected to the two conveying chains. The degreasing plate frame is a rectangular frame. Mesh screens are installed on both sides of the rectangular frame. Fiber ball filter material is filled between the rectangular frame and the mesh screen. Pins are installed on both sides of the other end of the rectangular frame. A through hole is opened at the bottom of the frame for the pin to extend into, a pin is inserted into the through hole and a spring is arranged between the bottom of the pin and the through hole, a magnet is embedded in the inner wall of the primary sedimentation groove, the pin shaft is adsorbed out by the magnet and pressed onto the surface of the conveyor chain; the cleaning component includes a hot water tank and an ultrasonic generator, the hot water tank is located above the primary sedimentation tank, ultrasonic generators are installed on the bottom and both sides of the outer wall of the hot water tank, clean water from the secondary sedimentation groove is introduced into the hot water tank, a heating wire is arranged in the hot water tank, and an oil collecting pipe is connected to the top of the hot water tank.

[0007] Preferably, a plurality of aeration heads arranged at equal intervals are provided at the bottom of the oxidation ditch, and a plurality of air supply pipes are installed at the bottom of the oxidation ditch. The plurality of aeration heads are installed on the air supply pipes at equal intervals, and air is supplied to the aeration heads through the air supply pipes. Each air supply pipe is rotatably connected to the bottom of the oxidation ditch, and mutually meshing swinging gears are provided between two adjacent air supply pipes. Racks that move up and down are installed on the outer sides of the gears on both sides, and a crank rocker mechanism is installed above the rack. The crank rocker mechanism is connected to a swinging impeller, and the impeller is in contact with the water surface; a plurality of elastic fillers arranged at equal intervals are installed in the oxidation ditch.

[0008] Preferably, the pretreatment mechanism includes a coarse fence, a fine fence and a pushing assembly, and the coarse fence and the fine fence are sequentially arranged in the water inlet channel, and a lifting assembly is arranged behind the coarse fence and the fine fence, and the lifting assembly is a lifting chain and a lifting gear, wherein lifting chains are arranged on both sides of the back of the coarse fence and the fine fence, and a gear driven by a motor is installed on the side of the primary sedimentation tank and the gear is meshed with the lifting chain, and a rotating rod is installed on the lifting chain by a rotating connection, and lifting plates arranged at equal intervals are fixed on the rotating rod, and the top surface of the lifting plate is a triangular inclined surface, and the lifting plate extends into the interval between the coarse fence and the fine fence, and the two sides of the lifting plate are the same width as the interval between the coarse fence and the fine fence, and a linkage rod is arranged under each rotating rod, a reinforcing rod is hinged between the linkage rod and the lifting plate, and a spring is arranged between the reinforcing rod and the rotating rod.

[0009] Preferably, the end of the primary sedimentation ditch is connected to the oxidation ditch, and a mixing assembly is arranged between the end of the primary sedimentation ditch and the oxidation ditch. The mixing assembly is connected to the sludge pump, and the sludge pump is connected to the bottom of the secondary sedimentation tank. The sludge pump pumps the sludge into the mixing assembly, and the mixing assembly is a porous hanging basket. The sludge pump directly pumps the sludge into the hanging basket, and the sludge in the porous hanging basket is pumped away by water flow.

[0010] Preferably, the secondary sedimentation ditch is butt-jointed with the end of the oxidation ditch, and a plurality of porous filter plates are installed in the secondary sedimentation ditch. The top of the porous filter plate is rotatably connected to the inner wall of the secondary sedimentation ditch. A mounting plate is provided on the back of the porous filter plate, and a scraper is installed on the front end surface of the porous filter plate. The scraper is in contact with the front side surface of the porous filter plate. The scraper and the mounting plate are connected by a connecting rod, so that the scraper, the mounting plate and the connecting rod form a frame that slides on the porous filter plate, and a spring is provided between the connecting rod and the top of the porous filter plate.

[0011] Preferably, a plurality of funnel-shaped holes are opened at the bottom of the secondary sedimentation ditch, each funnel-shaped hole is connected to a sludge pump through a pipe, a vertically arranged mud scraper impeller is arranged above each funnel-shaped hole, and an inclined rod connected to the funnel-shaped hole is installed in each funnel-shaped hole, and the inclined rod is connected to the mud scraper impeller and rotates synchronously.

[0012] Preferably, a gear rod is installed at the end of the secondary sedimentation ditch and is flush with the water surface. A triangular inclined plate is provided at the front end of the gear rod. The gear rod is a hollow rod. An oil suction hole is provided at the position of the gear rod near the secondary sedimentation ditch. The gear rod is connected to the pump through a pipeline and the pump works intermittently to extract the accumulated grease.

[0013] Compared with the prior art, the advantages of the present invention are: It is convenient to remove grease from sewage before biochemical treatment, thus reducing the aeration time of subsequent biochemical treatment and improving the efficiency of sewage treatment. It is convenient to remove solid impurities and avoid impurities getting stuck between the fences and affecting water flow. The aeration head can swing, so that the coverage area is larger, and the sewage close to the wall can also be aerated (reducing dead corners without aeration). While ensuring water quality, the flow rate can be increased, the aeration time can be reduced, and the efficiency can be improved. Secondary sedimentation uses a flowing method to settle the sludge, which is highly efficient and reduces floor space. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a top view of the present invention.

[0015] Figure 2 It is a schematic diagram of the water inlet channel and the pretreatment mechanism of the present invention.

[0016] Figure 3 It is a schematic diagram of the lifting assembly of the present invention.

[0017] Figure 4 It is a cross-sectional view of a primary sedimentation ditch of the present invention.

[0018] Figure 5 It is a schematic diagram of the grease adsorption mechanism of the present invention.

[0019] Figure 6 It is a front schematic diagram of the degreasing plate frame of the present invention.

[0020] Figure 7 It is a cross-sectional view of the degreasing plate frame of the present invention.

[0021] Figure 8 Schematic diagram of the oxidation ditch of the present invention.

[0022] Fig. 9 It is a schematic diagram of the aeration head and the air supply pipe of the present invention.

[0023] Fig.10 It is a schematic diagram of the secondary sedimentation ditch of the present invention.

[0024] Fig.11 It is a three-dimensional view of the porous filter plate and the scraper of the present invention.

[0025] Among them, 1. water inlet channel, 2. pretreatment mechanism, 3. coarse fence, 4. fine fence, 5. lifting component, 6. lifting chain, 7. lifting gear, 8. rotating rod, 9. lifting sheet, 10. linkage rod, 11. reinforcing rod, 12. primary sedimentation ditch, 13. aeration component, 14. unloading component, 15. grease adsorption mechanism, 16. degreasing plate frame, 17. rectangular frame, 18. mesh screen, 19. fiber ball filter material, 20. pin, 21. magnet, 22. conveying component, 23. conveying chain, 24. cleaning component, 2 5. Hot water tank, 26. Ultrasonic generator, 27. Oil collecting pipe, 28. Mixing assembly, 29. Sludge pump, 30. Oxidation ditch, 31. Aeration head, 32. Air supply pipe, 33. Swinging gear, 34. Rack, 35. Crank rocker mechanism, 36. Swinging impeller, 37. Elastic filler, 38. Secondary sedimentation ditch, 39. Porous filter plate, 40. Scraper, 41. Mounting plate, 42. Connecting rod, 43. Funnel-shaped hole, 44. Scraper impeller, 45. Inclined rod, 46. Gear rod, 47. Triangular inclined plate, 48. Oil suction hole. DETAILED DESCRIPTION

[0026] The present invention will now be further described with reference to the accompanying drawings.

[0027] like Figure 1-11 As shown, a municipal sewage treatment system comprises an inlet channel 1, a pretreatment mechanism 2, a primary sedimentation ditch 12, a grease adsorption mechanism 15, an oxidation ditch 30 and a secondary sedimentation ditch 38. Municipal sewage is transported to the inlet channel 1, wherein the inlet channel 1 is connected to the primary sedimentation ditch 12. The pretreatment mechanism 2 is arranged in the inlet channel 1. Most of the solid impurities in the sewage are removed by the pretreatment mechanism 2. The sewage passing through the pretreatment mechanism 2 contains sediment, grease, organic matter and nitrogen and phosphorus compounds. The grease adsorption mechanism 15 is arranged in the primary sedimentation ditch 12. Most of the sediment in the sewage in the primary sedimentation ditch 12 is removed. Sedimentation is performed, and the grease adsorption mechanism 15 adsorbs more than 95% of the grease in the sewage, which will not affect the subsequent biochemical treatment and reduce the time of the biochemical treatment. The tail of the primary sedimentation ditch 12 is connected with the oxidation ditch 30. The sewage entering the oxidation ditch 30 contains organic matter and nitrogen and phosphorus compounds. The organic matter and nitrogen and phosphorus compounds are removed by biochemical treatment. After oxidation, it is connected with the secondary sedimentation ditch 38. The sludge generated by the life reaction is precipitated through the secondary sedimentation ditch 38. The upper clear liquid can be used for urban cleaning and irrigation. If it needs to be discharged into rivers, it needs to be adsorbed and sterilized by activated carbon; An aeration assembly 13 is provided at the bottom of the primary sedimentation ditch 12. The aeration assembly 13 is a plurality of aeration pipes extending into the bottom of the primary sedimentation ditch 12. High-pressure gas is pumped into the bottom of the primary sedimentation ditch 12 by a pump. Organic matter and grease on the surface of the sediment are separated by aeration. The heavier sediment is deposited at the bottom of the primary sedimentation ditch 12. The bottom of the primary sedimentation ditch 12 is an inclined plane tilted to the left. The sediment on the inclined plane moves to the bottom. A discharge assembly is provided at the lowest part of the primary sedimentation ditch 12. The discharge assembly 14 is a pump connected to a discharge pipe, one end of the discharge pipe is connected to the pump, and the other end of the discharge pipe extends into the bottom of the primary sedimentation ditch 12 to pump away the silt; the grease adsorption mechanism 15 includes a degreasing plate frame 16, a conveying assembly 22 and a cleaning assembly 24, wherein a conveying assembly 22 is arranged in the primary sedimentation ditch 12, and a plurality of degreasing plate frames 16 are installed on the conveying assembly 22 with equal intervals, and the degreasing plate frames 16 are circulated and transported by the conveying assembly 22, and at the same time, the conveying assembly 22 The oil removal plate frame 16 is lifted and lowered. When the oil removal plate frame 16 is lowered, the oil removal plate frame 16 extends into the sewage. When the sewage flows in the primary sedimentation tank, the oil removal plate frame 16 absorbs the grease. After a period of adsorption, the oil removal plate frame 16 rises and leaves the water surface. Multiple oil removal plate frames 16 remove oil in turn. A cleaning component 24 is arranged above the primary sedimentation ditch 12. The oil removal plate frame 16 is lifted upward and immersed in the cleaning component 24 for cleaning. The oil removal plate frame 16 leaving the water surface is cleaned by the cleaning component 24, which is convenient for the next oil absorption. In this way, more than 95% of the grease in the sewage is adsorbed before biochemical treatment, so that the grease in the sewage is reduced, which will not affect the subsequent biochemical treatment (that is, when the grease in the sewage is heavy, the microorganisms in the biochemical treatment grow slowly, so that a relatively long aeration time is required to remove the organic matter and nitrogen and phosphorus compounds in the sewage, which reduces the efficiency of sewage treatment. Most of the grease is adsorbed before biochemical treatment, so that the efficiency of biochemical treatment is improved).

[0028] The conveying assembly 22 includes a conveying chain 23 and a conveying gear. Two groups of front and rear mounted columns are provided on the inner walls of both sides of the primary sedimentation tank by bolt fastening. A conveying gear driven by a motor is installed on each column through a bearing. Multiple conveying gears on the columns on the same side are meshed with the same conveying chain 23 for transmission, so as to realize the conveying of the conveying chain 23; one end of the degreasing plate frame 16 located at the top is rotatably connected to the two conveying chains 23 (a sleeve is fixed on the outer wall of the conveying chain 23 by welding) , rotating pins are fixed by welding at both ends of the degreasing plate frame 16 at the top, and the rotating pins extend into the sleeve for rotation). The degreasing plate frame 16 is a rectangular frame 17, and mesh screens 18 are installed on both sides of the rectangular frame 17 by bolt fastening. Fiber ball filter material 19 is filled between the rectangular frame 17 and the mesh screen 18. When sewage passes through the fiber ball filter material 19, due to the characteristics of the fiber ball filter material 19, the grease in the sewage passing through the fiber ball filter material 19 is adsorbed on the fiber ball filter material 19. Pins 20 are installed at both ends of the bottom, and through holes for the pins 20 to extend into are opened near the left and right ends of the bottom of the rectangular frame 17. The pins 20 are inserted into the through holes, and a spring is fixed between the bottom of the pins 20 and the through holes by welding. The pin shaft is retracted into the through hole by the spring, and a magnet 21 is embedded in the inner wall of the primary sedimentation groove 12. When the pin shaft moves to the position of the magnet 21, the magnet 21 sucks out the pin shaft (iron), and the pin shaft is pressed on the surface of the conveying chain 23, and the conveying chain 23 is rectangular; the cleaning component 24 includes The hot water tank 25 and the ultrasonic generator 26 are provided. The hot water tank 25 is located above the primary sedimentation tank. The bottom of the hot water tank 25 is fixed to the top of the primary sedimentation tank by bolts. The ultrasonic generator 26 is installed on the bottom and the outer walls of the hot water tank 25 by bolts. Clean water from the secondary sedimentation ditch 38 is introduced into the hot water tank 25. A powered heating wire is placed in the hot water tank 25. An oil collecting pipe 27 is connected to the top of the hot water tank 25. The bottom of the oil collecting pipe 27 extends into the cylinder to collect grease.When working, since the conveying chain 23 is rectangular, there are two groups of front and rear oil removal frame 16 extending into the primary sedimentation tank for grease filtering. The oil removal frame 16 at the front end is for primary filtering, and the oil removal frame 16 at the rear end is for secondary filtering. When working, the oil removal frame 16 at the front end performs primary filtering, so that the sewage is adsorbed by the oil removal frame 16. Due to the action of the magnet 21, the pin is pushed out, so that the pin is pressed on the front end surface of the conveying chain 23, thus preventing the oil removal frame 16 from swinging backward. If the oil removal frame 16 swings backward, there will be a gap between the oil removal frame 16 at the front end, so that the grease is not filtered cleanly. The primary filtration makes the oil removal frame 16 absorb grease near the front end surface. There is still a small amount of grease in the sewage filtered once, located at The front oil removal frame 16 moves upward under the action of the conveying chain 23 and immerses into the hot water tank 25. The fiber ball filter material 19 is cleaned by the hot water and ultrasonic waves in the hot water tank 25. The cleaned oil removal frame 16 moves backward and extends downward into the sewage for secondary filtration. There is a small amount of grease in the sewage after the primary filtration. After the sewage passes through the oil removal frame 16, the fiber ball filter material 19 absorbs the grease in the sewage. Since there is less grease, the oil removal frame 16 at the rear end swings slightly backward (water flow thrust) and does not affect the grease content in the sewage. The oil removal frame 16 at the rear end is transported forward under the action of the conveying chain 23. During the transportation process, the oil removal frame 16 at the rear end is transported to the front end for oil removal, thereby reducing the grease content in the sewage. ;

[0029] A plurality of aeration heads 31 arranged at equal intervals are provided at the bottom of the oxidation ditch 30, a plurality of air supply pipes 32 are installed at the bottom of the through-axis cylinder of the oxidation ditch 30, the cylinder is sleeved on the air supply pipes 32, the bottom of the cylinder is installed at the bottom of the oxidation ditch 30 by bolts, a plurality of aeration heads 31 are installed on the air supply pipes 32 at equal intervals (the aeration heads 31 are installed on the air supply pipes 32 by threaded joints), air is supplied to the aeration heads 31 by the air supply pipes 32, each air supply pipe 32 is rotationally connected to the bottom of the oxidation ditch 30 (rotational installation is achieved through the cylinder, so that the air supply pipe 32 can rotate at a small angle), mutually meshing swing gears 33 are fixed between two adjacent air supply pipes 32 by bolt fastening, racks 34 that move up and down are installed on the outer sides of the gears on both sides, a slide groove is opened on the inner wall of the oxidation ditch 30, the rack 34 is lifted and lowered in the slide groove, and when the rack 34 is lifted and lowered, the air supply pipe 32 rotates under the action of the gear, and the rack 34 is moved up and down by the gear. A crank rocker mechanism 35 is hingedly installed on the top of the oxidation ditch 30 above. The crank rocker mechanism 35 is installed on the top of the oxidation ditch 30 through bearings and bearing seats. The crank rocker mechanism 35 is connected to the swing impeller 36 by welding. The impeller is in contact with the water surface, and the swing impeller 36 drives the crank rocker mechanism 35 to rotate, so that the gear rotates and deflects back and forth through the air supply pipe 32. In this way, the aeration head 31 deflects within a certain angle, so that the aeration head 31 covers a larger range and avoids dead corners without aeration. The aeration head 31 is deflected directly toward the inner wall of the oxidation ditch 30, so as to avoid the situation where the water flowing along the inner wall of the oxidation ditch 30 is not aerated, resulting in unqualified sewage biochemical treatment, and avoid re-treatment. In this way, sufficient aeration can give priority to avoiding secondary treatment due to unqualified water quality; multiple elastic fillers 37 arranged at equal intervals are suspended in the oxidation ditch 30 by ropes.

[0030] The pretreatment mechanism 2 includes a coarse fence 3, a fine fence 4 and a lifting assembly 5. The coarse fence 3 and the fine fence 4 are sequentially arranged in the water inlet channel 1. The coarse fence 3 and the fine fence 4 are formed by fixing a plurality of steel sheets side by side. There is a gap between two adjacent steel sheets. The coarse fence 3 and the fine fence 4 are divided according to the size of the gap. A lifting assembly 5 is arranged behind the coarse fence 3 and the fine fence 4. A conveyor belt is installed below the top of the coarse fence 3 and the fine fence 4. Debris falls onto the coarse fence 3 and the fine fence 4. The conveyor belt is used for conveying, and the lifting component 5 is a lifting chain 6 and a lifting gear 7. The lifting chains 6 are arranged on both sides of the back of the coarse fence 3 and the fine fence 4. A gear driven by a motor is installed on the side of the primary sedimentation tank through a bearing, and the gear is meshed with the lifting chain 6. A rotating rod 8 is installed on the lifting chain 6 by a rotating connection (both ends of the rotating rod 8 are sleeved with cylinders, and the outer wall of the cylinder is fixed on the lifting chain 6 by welding). The lifting pieces 9 are fixed with equal intervals in a connection manner, and the top surfaces of the lifting pieces 9 are triangular inclined surfaces. The lifting pieces 9 extend into the intervals between the coarse fence 3 and the fine fence 4, and the two sides of the lifting pieces 9 are of equal width to the intervals between the coarse fence 3 and the fine fence 4. A linkage rod 10 is arranged under each rotating rod 8, and the linkage rod 10 is against the lifting chain 6. A reinforcing rod 11 is hinged between the linkage rod 10 and the lifting piece 9, and a spring is fixed between the reinforcing rod 11 and the rotating rod 8 by welding. When impurities are stuck between the steel sheets and the card is relatively tight, when the lifting piece 9 moves to the impurities, the linkage rod 10 moves downward, and the end of the lifting piece 9 swings downward, so that relatively hard debris can be avoided and the lifting component 5 can be prevented from being damaged. When encountering impurities stuck between the steel sheets, the left end of the lifting piece 9 swings downward and tilts, and is lifted upward by the lifting chain 6 technology, so that the upward lifting force is converted into a force to push the impurities to the left, so that it is convenient to push the impurities stuck between the steel sheets out from between the steel sheets.

[0031] The end of the primary sedimentation ditch 12 is connected to the oxidation ditch 30. A mixing assembly 28 is arranged between the end of the primary sedimentation ditch 12 and the oxidation ditch 30. The mixing assembly 28 is connected to a sludge pump 29. The sludge pump 29 is connected to the bottom of the secondary sedimentation tank. The sludge pump 29 pumps the sludge into the mixing assembly 28. The mixing assembly 28 is a porous hanging basket. Both sides of the porous hanging basket are fixed to the inner wall of the oxidation ditch 30 by bolts. The sludge pump 29 directly pumps the sludge into the hanging basket, and the sludge in the porous hanging basket is pumped away by water flow, thereby dispersing the sludge.

[0032] The secondary sedimentation ditch 38 is butt-jointed with the end of the oxidation ditch 30, and a plurality of porous filter plates 39 are installed in the secondary sedimentation ditch 38 through bearings. The top of the porous filter plate 39 is rotatably connected to the inner wall of the secondary sedimentation ditch 38, and a mounting plate 41 is arranged on the back of the porous filter plate 39, and the mounting plate 41 is in close contact with the back of the porous filter plate 39. A scraper is installed on the front end surface of the porous filter plate 39, and the scraper 40 is in contact with the front side surface of the porous filter plate 39. A connecting rod 42 is fixed between the scraper and the mounting plate 41 by welding, so that the scraper, the mounting plate 41 and the connecting rod 42 form a frame that slides on the porous filter plate 39, and the scraper, the mounting plate 41 and the connecting rod 42 are lifted and lowered on the porous filter plate 39. A spring is fixed between the tops by welding, and the scraper 40 is pulled upward by the spring; when working, the aperture of the porous filter plate 39 gradually decreases from left to right, and the porous filter plate 39 can block the sludge and quickly settle at the bottom. The sludge will be adsorbed on the porous filter plate 39, so that the flow rate of the porous filter plate 39 is reduced. Under the action of water flow, when there is more sludge on the porous filter plate 39, the bottom of the porous filter plate 39 swings downward, so that the horizontal scraper becomes inclined, and the scraper is pushed down along the porous filter plate 39 by the water flow, so that the sludge on the front end surface of the porous filter plate 39 is scraped clean, so that the flow rate of the porous filter plate 39 is increased, the porous filter plate 39 becomes vertical, and the scraper rises under the action of the spring.

[0033] A plurality of funnel-shaped holes 43 are provided at the bottom of the secondary sedimentation ditch 38, each of the funnel-shaped holes 43 is connected to the sludge pump 29 through a pipeline, a vertically arranged scraper impeller 44 is installed above each funnel-shaped hole 43 through a bearing and a bearing seat, and an inclined rod 45 in contact with the inner wall of the funnel-shaped hole 43 is installed in each funnel-shaped hole 43, the inclined rod 45 and the scraper impeller 44 are fixed by welding and rotate synchronously, and the sludge pump 29 is connected to the bottom of the funnel-shaped hole 43 through a pipeline.

[0034] A stopper rod 46 is installed on the inner side surface of the end of the secondary sedimentation groove 38 by bolts, and the stopper rod 46 is flush with the water surface. A triangular inclined plate 47 is fixed at the front end of the stopper rod 46 by welding. A small amount of suspended matter and grease are accumulated on both sides of the two ends of the stopper rod 46 through the triangular inclined plate 47. The stopper rod 46 is a hollow rod, and an oil suction hole 48 is opened at the position of the stopper rod 46 near the inner wall of the secondary sedimentation groove 38. The stopper rod 46 is connected to the pump through a pipeline and the pump works intermittently, so that the accumulated grease and suspended matter are pumped away. A stopper rod is installed on the inner side surface of the end of the secondary sedimentation groove by bolts, and the stopper rod is flush with the water surface. A triangular inclined plate is fixed at the front end of the stopper rod by welding. A small amount of suspended matter and grease are accumulated on both sides of the two ends of the stopper rod through the triangular inclined plate. The stopper rod is a hollow rod, and an oil suction hole is opened at the position of the stopper rod near the inner wall of the secondary sedimentation groove. The stopper rod is connected to the pump through a pipeline and the pump works intermittently, so that the accumulated grease and suspended matter are pumped away.

Claims

1. A municipal sewage treatment system, comprising an inlet channel, a pretreatment mechanism, a primary sedimentation ditch, a grease adsorption mechanism, an oxidation ditch and a secondary sedimentation ditch, wherein the inlet channel is connected to the primary sedimentation ditch, a pretreatment mechanism is arranged in the inlet channel, and most of the solid impurities in the sewage are removed by the pretreatment mechanism, characterized in that: A grease adsorption mechanism is provided in the primary sedimentation ditch, which is connected to the oxidation ditch at the tail of the primary sedimentation ditch and connected to the secondary sedimentation ditch after oxidation; An aeration assembly is arranged at the bottom of the primary sedimentation ditch, and the bottom of the primary sedimentation ditch is an inclined surface inclined to one side, and a discharging assembly is arranged at the lowest part of the primary sedimentation ditch; the grease adsorption mechanism includes an oil removal plate frame, a conveying assembly and a cleaning assembly, wherein a conveying assembly is arranged in the primary sedimentation ditch, and a plurality of oil removal plate frames are installed on the conveying assembly at equal intervals, and the oil removal plate frames are lifted and lowered by the conveying assembly, and a cleaning assembly is arranged above the primary sedimentation ditch, and the oil removal plate frame is lifted upward and immersed in the cleaning assembly for cleaning, so as to facilitate the next oil absorption.

2. An urban sewage treatment system according to claim 1, characterized in that: The conveying assembly includes a conveying chain and a conveying gear. Two groups of front and rear mounted columns are arranged on the inner walls on both sides of the primary sedimentation tank. A gear driven by a motor is installed on each column. Multiple conveying gears on the columns on the same side are meshed and driven with the same conveying chain. One end of the degreasing plate frame is rotatably connected to the two conveying chains. The degreasing plate frame is a rectangular frame. Mesh screens are installed on both sides of the rectangular frame. Fiber ball filter material is filled between the rectangular frame and the mesh screen. Pins are installed on both sides of the other end of the rectangular frame. A through hole is opened at the bottom for the pin to extend into, a pin is inserted into the through hole and a spring is arranged between the bottom of the pin and the through hole, a magnet is embedded in the inner wall of the primary sedimentation groove, the pin shaft is adsorbed out by the magnet and pressed onto the surface of the conveyor chain; the cleaning component includes a hot water tank and an ultrasonic generator, the hot water tank is located above the primary sedimentation tank, ultrasonic generators are installed on the bottom and both sides of the outer wall of the hot water tank, clean water from the secondary sedimentation groove is introduced into the hot water tank, a heating wire is arranged in the hot water tank, and an oil collecting pipe is connected to the top of the hot water tank.

3. A municipal sewage treatment system according to claim 2, characterized in that A plurality of aeration heads arranged at equal intervals are arranged at the bottom of the oxidation ditch, and a plurality of air supply pipes are installed at the bottom of the oxidation ditch. The plurality of aeration heads are installed on the air supply pipes at equal intervals, and air is supplied to the aeration heads through the air supply pipes. Each air supply pipe is rotatably connected to the bottom of the oxidation ditch, and mutually meshing swinging gears are arranged between two adjacent air supply pipes. Racks that move up and down are installed on the outer sides of the gears on both sides, and a crank rocker mechanism is installed above the rack. The crank rocker mechanism is connected to a swing impeller, and the impeller is in contact with the water surface; a plurality of elastic fillers arranged at equal intervals are installed in the oxidation ditch.

4. An urban sewage treatment system according to claim 3, characterized in that: The pretreatment mechanism includes a coarse fence, a fine fence and a pushing assembly. The coarse fence and the fine fence are sequentially arranged in the water inlet channel. A lifting assembly is arranged behind the coarse fence and the fine fence. The lifting assembly is a lifting chain and a lifting gear. Lifting chains are arranged on both sides of the back of the coarse fence and the fine fence. A gear driven by a motor is installed on the side of the primary sedimentation tank and the gear is meshed with the lifting chain. A rotating rod is installed on the lifting chain by a rotating connection. Lifting plates arranged at equal intervals are fixed on the rotating rod. The top surface of the lifting plate is a triangular inclined surface. The lifting plate extends into the interval between the coarse fence and the fine fence and the two sides of the lifting plate are the same width as the interval between the coarse fence and the fine fence. A linkage rod is arranged under each rotating rod. A reinforcing rod is hinged between the linkage rod and the lifting plate, and a spring is arranged between the reinforcing rod and the rotating rod.

5. An urban sewage treatment system according to claim 4, characterized in that: The end of the primary sedimentation ditch is connected with the oxidation ditch. A mixing assembly is arranged between the end of the primary sedimentation ditch and the oxidation ditch. The mixing assembly is connected with a sludge pump. The sludge pump is connected with the bottom of the secondary sedimentation tank. The sludge pump pumps the sludge into the mixing assembly. The mixing assembly is a porous hanging basket. The sludge pump directly pumps the sludge into the hanging basket, and the sludge in the porous hanging basket is pumped away by water flow.

6. An urban sewage treatment system according to claim 5, characterized in that: The secondary sedimentation ditch is butt-jointed with the end of the oxidation ditch, and a plurality of porous filter plates are installed in the secondary sedimentation ditch. The top of the porous filter plate is rotatably connected to the inner wall of the secondary sedimentation ditch, and a mounting plate is arranged on the back of the porous filter plate. A scraper is installed on the front end surface of the porous filter plate, and the scraper is in contact with the front side surface of the porous filter plate. The scraper and the mounting plate are connected by a connecting rod, so that the scraper, the mounting plate and the connecting rod form a frame that slides on the porous filter plate, and a spring is arranged between the connecting rod and the top of the porous filter plate.

7. An urban sewage treatment system according to claim 6, characterized in that: A plurality of funnel-shaped holes are opened at the bottom of the secondary sedimentation ditch, each of which is connected to a sludge pump through a pipeline, a vertically arranged mud scraper impeller is arranged above each funnel-shaped hole, and an inclined rod connected to the funnel-shaped hole is installed in each funnel-shaped hole, the inclined rod is connected to the mud scraper impeller and rotates synchronously.

8. An urban sewage treatment system according to claim 7, characterized in that: A lever is installed at the end of the secondary sedimentation ditch and is flush with the water surface. A triangular inclined plate is provided at the front end of the lever. The lever is a hollow rod. An oil suction hole is provided at a position of the lever close to the secondary sedimentation ditch. The lever is connected to the pump through a pipeline and the pump works intermittently to extract the accumulated grease.

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