Sewage treatment system and method for waste incineration power plant

Abstract

The invention relates to the technical field of sewage treatment, in particular to a sewage treatment system and method for a waste incineration power plant, and the sewage treatment system comprises a primary treatment unit, a precipitation treatment unit, a biochemical treatment unit, a filtration treatment unit and a disinfection treatment unit which are sequentially arranged along the sewage flowing direction; the sedimentation treatment unit comprises an annular coagulative precipitation tank, an annular air floatation tank and a circular adjusting tank which are sequentially arranged from outside to inside, a collecting well is arranged in the annular air floatation tank, and a scum salvaging mechanism for salvaging scum into the collecting well is arranged on the annular air floatation tank. The method comprises the following steps: firstly, treating sewage by using a coagulant in an annular coagulative precipitation tank; then the sewage is fed into the annular air floatation tank, and pollutants such as suspended solids and grease which are difficult to settle in the sewage are attached to the air bubbles and float to the water surface by generating a large number of fine air bubbles, so that the pollutants are effectively removed, the burden of a subsequent treatment process is favorably relieved, and the overall treatment efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a sewage treatment system and method for a waste incineration power plant. Background Art

[0002] The wastewater treatment system of a waste incineration power plant is mainly responsible for treating wastewater generated during the incineration process, including boiler dust removal and washing wastewater, boiler blowdown wastewater, exhaust gas soot washing wastewater, flue gas condensate, ash washing wastewater, etc. These wastewaters usually contain high concentrations of organic matter, heavy metal ions and other pollutants, and require special treatment processes to meet emission standards or be reused.

[0003] At present, the sewage treatment process of waste incineration power plants usually includes three stages: physical treatment, chemical treatment and biological treatment, so that the wastewater generated by waste incineration power plants can meet the prescribed emission standards. Among them, the chemical treatment stage generally adopts the method of coagulation and sedimentation, by adding chemical agents to make the colloidal particles and suspended matter in the wastewater condense into larger flocs, and then precipitate and separate. This process can effectively remove pollutants such as organic matter and heavy metal ions in the wastewater.

[0004] However, it was found during use that only coagulation and sedimentation cannot effectively remove suspended matter, grease and other pollutants that are difficult to settle naturally in sewage. In order to remove the above pollutants, the prior art generally uses flotation machines for treatment, but a separate flotation machine is set up, and the sewage after coagulation and sedimentation treatment needs to be transported to the flotation machine through pipelines and pumps, which undoubtedly increases the cost of sewage treatment. To this end, we propose a sewage treatment system and method for waste incineration power plants to effectively solve the above drawbacks. Summary of the invention

[0005] The object of the present invention is to provide a wastewater treatment system and method for a waste incineration power plant, so as to solve the problems raised in the above-mentioned background technology.

[0006] The present invention is realized by the following technical scheme: a wastewater treatment system for a waste incineration power plant, comprising a preliminary treatment unit, a sedimentation treatment unit, a biochemical treatment unit, a filtration treatment unit and a disinfection treatment unit arranged in sequence along the flow direction of the wastewater; The sedimentation treatment unit comprises an annular coagulation sedimentation tank, an annular flotation tank and a circular regulating tank which are arranged in sequence from outside to inside, the annular coagulation sedimentation tank is connected to the preliminary treatment unit through a pipeline, and the circular regulating tank is connected to the biochemical treatment unit through a pipeline; A releaser is provided inside the annular air flotation tank, and an air dissolving mechanism is provided outside the annular air flotation tank, and an output end of the air dissolving mechanism is connected to the releaser; A collection well is arranged in the annular air flotation pool, and the liquid level in the annular air flotation pool is lower than the top surface height of the collection well; a slag scooping mechanism for scooping slag into the collection well is arranged on the annular air flotation pool.

[0007] Optionally, the slag scooping mechanism includes two annular vertical baffles distributed in concentric circles, the two annular vertical baffles are respectively arranged on the inner and outer sides of the top surface of the annular air flotation tank, annular slide grooves are arranged on the sides of the two annular vertical baffles close to each other, a slide rod slides in each annular slide groove, and a connecting shaft arranged along the radial direction of the annular air flotation tank is fixedly connected between the two slide rods; A connecting plate arranged in the vertical direction is fixedly connected to the connecting shaft, and an arc-shaped slag scooping box adapted to the annular air flotation tank is fixedly connected to the lower end of the connecting plate; A vehicle body moving along the circumference of the annular air flotation pool is arranged on the top of the annular vertical partition, and a guide frame rotatably connected to the connecting shaft is movably penetrated on the vehicle body along the vertical direction.

[0008] Optionally, the annular chute is composed of a long arc chute arranged at the proximal end of the lower end of the annular vertical partition, a short arc chute arranged at the proximal end of the upper end of the annular vertical partition, and a first inclined chute and a second inclined chute respectively connected to both ends of the short arc chute and communicating with the long arc chute; When the slide bar slides in the long arc groove, the arc-shaped slag scoop box is located below the liquid surface of the annular air flotation tank; when the slide bar slides in the short arc groove, the arc-shaped slag scoop box is located above the collection well.

[0009] Optionally, the arc-shaped slag scooping box is composed of a fixed half box and a movable half box that cooperate with each other; The fixed half box is fixed to the lower end of the connecting plate, a contraction groove adapted to the movable half box is provided in the fixed half box, and a telescopic spring for applying an outward elastic force to the movable half box is arranged in the contraction groove.

[0010] Optionally, the movable half box is rotatably connected to an outer side surface away from the fixed half box with a roller, and the roller is distributed along the radial direction of the annular flotation tank.

[0011] Optionally, an incomplete gear is fixedly connected to the proximal end of one end of the connecting shaft, and an arc-shaped rack located below the short arc groove and matching with the incomplete gear is fixed on the side of the corresponding annular vertical partition, and the corresponding central angle of the tooth of the incomplete gear is between 90° and 180°.

[0012] Optionally, the guide frame includes a plurality of guide rods that move through the vehicle body in a vertical direction, and a sleeve that is movably mounted on a connecting shaft is fixedly connected to the lower end of each guide rod, and a torsion spring is arranged in each sleeve, one torsion arm of the torsion spring is connected to the sleeve, and the other torsion arm of the torsion spring is connected to the connecting shaft. In a natural state, the arc-shaped slag scoop box is in a horizontal posture.

[0013] Optionally, the top of the annular vertical partition is integrally formed with a flange, and the vehicle body includes a vehicle plate radially arranged along the annular air flotation tank, and a first side plate and a second side plate are respectively fixedly connected to both ends of the vehicle plate; Two first wheels are distributed on the first side plate, respectively located on the upper and lower sides of the corresponding flange; a connecting rod is fixedly connected to the outer side of the first side plate, and a support platform is arranged at the central axis of the annular flotation tank, and one end of the connecting rod away from the first side plate is rotatably connected to the support platform.

[0014] Optionally, the second side panel is provided with a second wheel and a driving gear respectively located on the upper and lower sides of the corresponding flange, a gear ring is fixedly connected to the bottom surface of one of the flanges, the driving gear is meshed with the gear ring, and a motor connected to the driving gear is installed on the second side panel.

[0015] The present invention also proposes a wastewater treatment method for a waste incineration power plant, comprising the following steps: Step 1: The wastewater in the waste incineration power plant enters the preliminary treatment unit for coarse screening; Step 2: The sewage after coarse screening enters the sedimentation treatment unit for solid-liquid separation; Step 3: The wastewater after solid-liquid separation enters the biochemical treatment unit, where microorganisms are used to degrade organic matter in the wastewater; Step 4: The degraded sewage enters the filtration treatment unit to remove tiny particles and microorganisms in the sewage; Step 5: Disinfect the sewage treated above by a disinfection treatment unit.

[0016] Compared with the prior art, the present invention provides a wastewater treatment system and method for a waste incineration power plant, which has the following beneficial effects: 1. The present invention sets an annular coagulation sedimentation tank, an annular flotation tank and a circular regulating tank. First, a coagulant is used in the annular coagulation sedimentation tank to treat the sewage, so that the colloidal particles and suspended matter in the sewage are condensed into larger flocs for sedimentation separation; then the sewage is sent to the annular flotation tank, and a large number of fine bubbles are generated, so that the pollutants such as suspended matter, grease and the like that are difficult to settle in the sewage are attached to the bubbles and float to the water surface, so that they are effectively removed. Therefore, in the present invention, the coagulation sedimentation tank and the annular flotation tank are integrated, and there is no need to transport the sewage over a long distance, which greatly reduces the treatment cost of the present invention.

[0017] 2. The precipitation treatment unit of the present invention adopts a ring-shaped design, which can achieve a larger treatment capacity within a limited floor area, thereby improving land utilization; and due to its compact structure, it is convenient for centralized management and maintenance.

[0018] 3. The present invention sets a collection well and a slag scooping mechanism. Under normal conditions, the arc-shaped slag scooping box is in a horizontal state and is located below the liquid surface of the annular flotation tank, and moves circumferentially along the annular flotation tank, so as to gather the slag on the liquid surface of the annular flotation tank to the collection well; then, through the cooperation of the sliding rod and the first inclined groove, the arc-shaped slag scooping box can be automatically moved upward to the top of the collection well, and then, through the cooperation of the incomplete gear and the arc-shaped rack, the arc-shaped slag scooping box can be driven to flip, and the slag scooped out of the arc-shaped slag scooping box can be poured into the collection well, thereby realizing effective separation of solids. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a block diagram of the sewage treatment system of the present invention; Figure 2 is a top view of the precipitation treatment unit of the present invention; Figure 3 It is a partial cross-sectional view of the annular air flotation tank of the present invention; Figure 4 It is a structural schematic diagram of the arc-shaped slag scooping box of the present invention; Figure 5 It is a structural schematic diagram of the slide bar of the present invention; Figure 6 It is a structural schematic diagram of the annular chute of the present invention; Figure 7 This is a cross-sectional view of the structure of the fixed half box of the present invention; Figure 8 It is a structural schematic diagram of the guide frame of the present invention; Fig. 9 for Figure 3 A local enlarged schematic diagram of point A in the middle.

[0020] In the figure: 1. Preliminary treatment unit; 2. Sedimentation treatment unit; 201. Annular coagulation sedimentation tank; 202. Annular flotation tank; 203. Circular regulating tank; 3. Biochemical treatment unit; 4. Filtration treatment unit; 5. Disinfection treatment unit; 6. Collection well; 7. Slag scavenging mechanism; 701. Annular vertical partition; 702. Annular chute; 7021. Long arc chute; 7022. Short arc chute; 7023. First chute; 7024. Second chute; 703. Slide rod; 704. Connecting shaft; 705. Connecting plate; 706. Arc slag scavenging box; 707. 061, fixed half box; 7062, movable half box; 707, vehicle body; 7071, vehicle plate; 7072, first side plate; 7073, second side plate; 7074, first wheel; 7075, connecting rod; 7076, driving gear; 7077, motor; 7078, second wheel; 708, guide frame; 7081, guide rod; 7082, sleeve; 7083, torsion spring; 709, incomplete gear; 7010, arc-shaped rack; 8, contraction groove; 9, telescopic spring; 10, flange; 11, roller; 12, gear ring. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1: Please refer to Figures 1 to 9 A wastewater treatment system and method for a waste incineration power plant, comprising a preliminary treatment unit 1, a sedimentation treatment unit 2, a biochemical treatment unit 3, a filtration treatment unit 4 and a disinfection treatment unit 5 arranged in sequence along the flow direction of the wastewater. The preliminary treatment unit 1 comprises a water collection well and a screen machine arranged in sequence along the flow direction of the wastewater. The wastewater generated in the waste incineration power plant enters the water collection well for collection, and then is coarsely screened and filtered through the screen machine to remove larger impurities in the wastewater. The biochemical treatment unit 3 comprises an anaerobic tank, an anoxic tank and an aerobic tank arranged in sequence along the flow direction of the wastewater, and uses microorganisms to degrade organic matter in the wastewater. The filtration treatment unit 4 comprises a bag filter, an ultrafilter and a reverse osmosis filter arranged in sequence along the flow direction of the wastewater, and effectively removes tiny particles and microorganisms in the wastewater. The disinfection treatment unit 5 comprises an activated carbon adsorption tank, an ultraviolet disinfection tank and a clear water tank arranged in sequence along the flow direction of the wastewater, and first uses activated carbon to adsorb the wastewater, and then uses ultraviolet rays to sterilize and disinfect the wastewater, so that the wastewater entering the clear water tank can meet the national emission standards.

[0023] In this embodiment, the sedimentation treatment unit 2 includes an annular coagulation sedimentation tank 201, an annular flotation tank 202 and a circular regulating tank 203 arranged in sequence from the outside to the inside. The annular coagulation sedimentation tank 201 is connected to the preliminary treatment unit 1 through a pipeline, and the circular regulating tank 203 is connected to the biochemical treatment unit 3 through a pipeline.

[0024] Specifically, a releaser is provided inside the annular air flotation pool 202, and an air dissolving mechanism is provided outside the annular air flotation pool 202. The output end of the air dissolving mechanism is connected to the releaser, and a large number of fine bubbles can be generated in the water. This is a prior art and will not be described in detail here. A collection well 6 is provided inside the annular air flotation pool 202, and the liquid level inside the annular air flotation pool 202 is lower than the top surface height of the collection well 6; a slag scooping mechanism 7 for scooping slag into the collection well 6 is provided on the annular air flotation pool 202. First, the sewage is treated with a coagulant in the annular coagulation sedimentation tank 201, so that the colloidal particles and suspended matter in the sewage are condensed into larger flocs for sedimentation and separation; the sewage is then sent to the annular flotation tank 202, which generates a large number of fine bubbles so that the suspended matter, grease and other pollutants that are difficult to settle in the sewage are attached to the bubbles and float to the water surface, thereby being effectively removed; finally, the sewage is sent to the subsequent treatment process through the circular regulating tank 203, which helps to reduce the burden of the subsequent treatment process and improve the overall treatment efficiency.

[0025] It should be noted that the top of the side wall between the annular coagulation sedimentation tank 201 and the annular air flotation tank 202 has an overflow hole, and a gate is provided in the overflow hole. When the gate is closed, the annular coagulation sedimentation tank 201 and the annular air flotation tank 202 are not connected to each other. When the gate is opened, the water in the annular coagulation sedimentation tank 201 can automatically flow into the annular air flotation tank 202 through the overflow hole. Therefore, the present invention does not need to use a large number of pipelines to pump sewage, which helps to reduce the cost of sewage treatment.

[0026] In the prior art, a flotation machine is usually used to generate a large number of fine bubbles in the water, so that the air is attached to the suspended particles in the form of highly dispersed tiny bubbles, resulting in a state where the density is less than that of water, and then the particles are floated on the water surface by the buoyancy principle, thereby achieving solid-liquid separation. In addition, a scraper is provided in conjunction with the flotation machine to scrape the scum layer on the water surface into a scum tank or collection container.

[0027] However, the existing flotation machine is generally long and strip-shaped, and the scraper used is also long and strip-shaped, which cannot adapt to the annular flotation tank 202 of the present application. Therefore, a unique design is now made for the slag removal mechanism 7, and the specific design is as follows: The slag scooping mechanism 7 includes two annular vertical baffles 701 distributed in concentric circles, and the two annular vertical baffles 701 are respectively arranged on the inner and outer sides of the top surface of the annular air flotation tank 202, and the two annular vertical baffles 701 coincide with the central axis of the annular air flotation tank 202. An annular slide groove 702 is arranged on the side surfaces of the two annular vertical baffles 701 close to each other, and a slide rod 703 slides in each annular slide groove 702. A connecting shaft 704 arranged along the radial direction of the annular air flotation tank 202 is fixedly connected between the two slide rods 703, as shown in FIG. Figures 3 to 6When the slide bar 703 slides in the annular chute 702, it can drive the connecting shaft 704 to move along the circumference of the annular air flotation tank 202. A connecting plate 705 arranged in the vertical direction is fixedly connected to the connecting shaft 704, and an arc-shaped slag scooping box 706 adapted to the annular air flotation tank 202 is fixedly connected to the lower end of the connecting plate 705. The upper end of the arc-shaped slag scooping box 706 is open, and the slag in the annular air flotation tank 202 can be scooped.

[0028] The slag scooping mechanism 7 also includes a vehicle body 707 disposed on the top of the annular vertical partition 701 and movable in the circumferential direction along the annular flotation tank 202. In this embodiment, a flange 10 is integrally formed on the top of the annular vertical partition 701, and a gear ring 12 is fixedly connected to the bottom of one of the flanges 10. The vehicle body 707 includes a vehicle plate 7071 disposed radially along the annular flotation tank 202, and a first side plate 7072 and a second side plate 7073 are fixedly connected at both ends of the vehicle plate 7071. Among them, two first wheels 7074 are distributed on the first side plate 7072, which are located on the upper and lower sides of the corresponding flange 10, and the two first wheels 7074 can move circumferentially along the flange. In addition, a connecting rod 7075 is fixedly connected to the outer side of the first side plate 7072, and a support platform is provided at the central axis of the annular air flotation tank 202. The end of the connecting rod 7075 away from the first side plate 7072 is rotatably connected to the support platform. Through the cooperation of the connecting rod 7075 and the support platform, the vehicle plate 7071 can stably move along the circumference of the annular air flotation tank 202. Finally, the second side plate 7073 is provided with a second wheel 7078 and a driving gear 7076 respectively located on the upper and lower sides of the corresponding flange 10. The driving gear 7076 is meshed with the gear ring 12, and a motor 7077 drivingly connected to the driving gear 7076 is installed on the second side plate 7073. When the motor 7077 drives the driving gear 7076 to rotate, the driving gear 7076 is meshed with the gear ring 12 , so that the vehicle plate 7071 can move circumferentially along the flange 10 , thereby enabling the arc-shaped slag box 706 to move circumferentially in the annular flotation tank 202 .

[0029] In addition, a guide frame 708 rotatably connected to the connecting shaft 704 is movably passed through the vehicle body 707 in the vertical direction. The connecting shaft 704 can move along with the vehicle body 707 through the guide frame 708, and the connecting shaft 704 can move up and down along with the slide bar 703. In this embodiment, the guide frame 708 includes a plurality of guide rods 7081 movably passed through the vehicle body 707 in the vertical direction. A sleeve 7082 movably sleeved on the connecting shaft 704 is fixedly connected to the lower end of each guide rod 7081, and the connecting shaft 704 can rotate in the sleeve 7082. A torsion spring 7083 is arranged in each sleeve 7082, one of the torsion arms of the torsion spring 7083 is connected to the sleeve 7082, and the other torsion arm of the torsion spring 7083 is connected to the connecting shaft 704, such as Figure 8 In a normal state, the torsion force of the torsion spring 7083 enables the connecting plate 705 to maintain a vertical state.

[0030] It is worth mentioning that the annular chute 702 is composed of a long arc groove 7021 arranged at the proximal end of the lower end of the annular vertical partition 701, a short arc groove 7022 arranged at the proximal end of the upper end of the annular vertical partition 701, and a first inclined groove 7023 and a second inclined groove 7024 respectively connected to both ends of the short arc groove 7022 and communicating with the long arc groove 7021. Figure 6 As shown. When the slide bar 703 slides in the long arc groove 7021, the connecting plate 705 is at the lowest point, so that the arc-shaped slag scoop box 706 is located below the liquid surface of the annular flotation tank 202. At the same time, under the action of the torsion spring 7083, the arc-shaped slag scoop box 706 can remain horizontal. When the slide bar 703 moves in the first chute 7023, it can drive the connecting shaft 704 to move upward, thereby driving the arc-shaped slag scoop box 706 to move upward, and then scoop up the slag in the annular flotation tank 202. When the slide bar 703 slides in the short arc groove 7022, the arc-shaped slag scoop box 706 is located above the collection well 6. When the slide bar 703 slides in the second chute 7024, it can drive the arc-shaped slag scoop box 706 to move downward until the slide bar 703 slides into the long arc groove 7021, and the arc-shaped slag scoop box 706 re-extends below the liquid surface of the annular flotation tank 202.

[0031] The structure of the arc-shaped slag scoop box 706 is described below: The arc-shaped slag scooping box 706 is composed of a fixed half box 7061 and a movable half box 7062, and the movable half box 7062 can be retracted in the fixed half box 7061, so that when the slide bar 703 slides in the first inclined groove 7023, the movable half box 7062 conflicts with the collection well 6, thereby driving the arc-shaped slag scooping box 706 to shrink, so that the arc-shaped slag scooping box 706 can move upward smoothly, and at the same time, the arc-shaped slag scooping box 706 will not leave a large gap with the collection well 6, so that all the slag in the annular flotation tank 202 can be well scooped. Specifically, the fixed half box 7061 is fixed to the lower end of the connecting plate 705, and a shrinkage groove 8 adapted to the movable half box 7062 is opened in the fixed half box 7061, and the movable half box 7062 can shrink in the shrinkage groove 8. A telescopic spring 9 for applying an outward elastic force to the movable half box 7062 is provided in the contraction groove 8, so that the movable half box 7062 is in an extended state under normal conditions. A protrusion located in the contraction groove 8 is fixed on the movable half box 7062 to prevent the movable half box 7062 from breaking away from the fixed half box 7061.

[0032] Preferably, the movable half box 7062 is rotatably connected to the outer side of the fixed half box 7061, and the roller 11 is distributed along the radial direction of the annular flotation tank 202. By providing the roller 11, the movable half box 7062 can be prevented from directly contacting the collection well 6, thereby avoiding wear of the movable half box 7062. When in use, when the slide bar 703 slides in the first chute 7023, the arc-shaped slag scooping box 706 moves upward, and at the same time, the roller 11 contacts the outer surface of the collection well 6, driving the arc-shaped slag scooping box 706 to shrink, and preventing friction between the movable half box 7062 and the collection well 6.

[0033] It should be noted that an incomplete gear 709 is fixedly connected to the proximal end of one end of the connecting shaft 704, and an arc-shaped rack 7010 located below the short arc groove 7022 and matched with the incomplete gear 709 is fixed on the side of the corresponding annular vertical partition 701, and the corresponding central angle of the teeth of the incomplete gear 709 is between 90° and 180°. Horizontal attitude When the slide bar 703 slides in the short arc groove 7022 and the incomplete gear 709 meshes with the arc-shaped rack 7010, the connecting shaft 704 can be driven to rotate clockwise to flip the arc-shaped slag scoop box 706, so that the slag in the arc-shaped slag scoop box 706 can be poured into the collection well 6; and the rotation angle of the arc-shaped slag scoop box 706 can exceed 90° and be less than 180°, so that all the slag in the arc-shaped slag scoop box 706 can be poured out and not easily accumulated. When the incomplete gear 709 completely passes the arc-shaped rack 7010, the arc-shaped slag scoop box 706 is reset to a horizontal position under the action of the torsion spring 7083. Embodiment 2: This application proposes a method for treating wastewater for a waste incineration power plant, which is applicable to the wastewater treatment system for a waste incineration power plant in Embodiment 1, and comprises the following steps: Step 1: The wastewater in the waste incineration power plant enters the preliminary treatment unit 1 and undergoes coarse screening; The sewage generated in the waste incineration power plant is first collected in the collection well through pipes, and then coarsely filtered through equipment such as screen machines to remove larger impurities in the sewage.

[0034] Step 2: The sewage after coarse screening enters the sedimentation treatment unit 2 for solid-liquid separation; The sewage first enters the annular coagulation sedimentation tank 201, into which a coagulant is added to aggregate the impurities in the sewage into larger flocs, which can then settle. The sewage is then sent to the annular flotation tank 202, where a large number of fine bubbles are generated, so that the pollutants such as suspended solids and grease that are difficult to settle in the sewage are attached to the bubbles and float to the water surface to form scum.

[0035] The vehicle body 707 moves circumferentially along the annular flotation tank 202, driving the slide bar 703 to slide in the annular slide groove 702. When the slide bar 703 slides in the long arc groove 7021, since the arc-shaped slag scooping box 706 is located below the liquid surface of the annular flotation tank 202, the slag can be gathered together through the connecting plate 705.

[0036] When the slide bar 703 slides in the first chute 7023, it can drive the arc-shaped slag scooping box 706 to move upwards. At the same time, the roller 11 contacts the collection well 6, driving the arc-shaped slag scooping box 706 to contract, thereby scooping up the floating slag.

[0037] When the slide bar 703 slides in the short arc groove 7022 and the incomplete gear 709 meshes with the arc rack 7010 , it can drive the connecting shaft 704 to rotate clockwise to flip the arc slag box 706 , thereby pouring the slag in the arc slag box 706 into the collection well 6 .

[0038] When the slide bar 703 slides in the second chute 7024 , under the action of the torsion spring 7083 , the arc-shaped slag scooping box 706 gradually turns to a horizontal state and extends below the liquid surface of the annular air flotation tank 202 .

[0039] This process is repeated until all the scum in the annular flotation tank 202 is scooped into the collection well 6 .

[0040] Step 3: After solid-liquid separation, the sewage enters the biochemical treatment unit 3, and is treated in the pressure oxygen tank, the anoxic tank and the aerobic tank in sequence, where the organic matter in the sewage can be degraded by microorganisms; Step 4: The degraded sewage enters the filtration treatment unit 4, and passes through a bag filter, an ultrafilter and a reverse osmosis filter to effectively remove tiny particles and microorganisms in the sewage; Step 5: disinfect the sewage treated above by the disinfection treatment unit 5; specifically, firstly, the bacteria and pathogens remaining in the water are killed by activated carbon adsorption and then by ultraviolet rays, so that the water meets the environmental discharge standard.

[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wastewater treatment system for a waste incineration power plant, characterized in that: It comprises a preliminary treatment unit (1), a sedimentation treatment unit (2), a biochemical treatment unit (3), a filtration treatment unit (4) and a disinfection treatment unit (5) which are arranged in sequence along the flow direction of the sewage; The sedimentation treatment unit (2) comprises an annular coagulation sedimentation tank (201), an annular flotation tank (202) and a circular regulating tank (203) which are arranged in sequence from the outside to the inside, the annular coagulation sedimentation tank (201) is conductively connected to the preliminary treatment unit (1) via a pipeline, and the circular regulating tank (203) is conductively connected to the biochemical treatment unit (3) via a pipeline; A releaser is provided inside the annular air flotation tank (202), and an air dissolving mechanism is provided outside the annular air flotation tank (202), wherein an output end of the air dissolving mechanism is connected to the releaser; A collection well (6) is provided in the annular air flotation pool (202), and the liquid level in the annular air flotation pool (202) is lower than the top surface of the collection well (6); a slag scooping mechanism (7) for scooping slag into the collection well (6) is provided on the annular air flotation pool (202).

2. A wastewater treatment system for a waste incineration power plant according to claim 1, characterized in that: The slag scooping mechanism (7) comprises two annular vertical baffles (701) arranged in a concentric circle shape, the two annular vertical baffles (701) are respectively arranged on the inner and outer sides of the top surface of the annular flotation tank (202), annular slide grooves (702) are arranged on the sides of the two annular vertical baffles (701) close to each other, a slide bar (703) slides in each annular slide groove (702), and a connecting shaft (704) arranged along the radial direction of the annular flotation tank (202) is fixedly connected between the two slide bars (703); A connecting plate (705) arranged in a vertical direction is fixedly connected to the connecting shaft (704), and an arc-shaped slag scooping box (706) adapted to the annular flotation tank (202) is fixedly connected to the lower end of the connecting plate (705); A vehicle body (707) that moves circumferentially along the annular air flotation tank (202) is provided on the top of the annular vertical partition (701), and a guide frame (708) that is rotatably connected to the connection shaft (704) is movably provided on the vehicle body (707) in the vertical direction.

3. A wastewater treatment system for a waste incineration power plant according to claim 2, characterized in that: The annular chute (702) is composed of a long arc groove (7021) arranged at the proximal end of the lower end of the annular vertical partition (701), a short arc groove (7022) arranged at the proximal end of the upper end of the annular vertical partition (701), and a first inclined groove (7023) and a second inclined groove (7024) respectively connected to both ends of the short arc groove (7022) and communicating with the long arc groove (7021); When the sliding rod (703) slides in the long arc groove (7021), the arc-shaped slag scoop box (706) is located below the liquid surface of the annular flotation tank (202); when the sliding rod (703) slides in the short arc groove (7022), the arc-shaped slag scoop box (706) is located above the collection well (6).

4. A wastewater treatment system for a waste incineration power plant according to claim 3, characterized in that: The arc-shaped slag scooping box (706) is composed of a fixed half box (7061) and a movable half box (7062) that cooperate with each other; The fixed half box (7061) is fixed to the lower end of the connecting plate (705), a contraction groove (8) adapted to the movable half box (7062) is provided in the fixed half box (7061), and a telescopic spring (9) for applying an outward elastic force to the movable half box (7062) is provided in the contraction groove (8).

5. A wastewater treatment system for a waste incineration power plant according to claim 4, characterized in that: The movable half box (7062) is rotatably connected to a roller (11) on an outer side surface away from the fixed half box (7061), and the roller (11) is distributed along the radial direction of the annular air flotation tank (202).

6. A wastewater treatment system for a waste incineration power plant according to claim 3, characterized in that: An incomplete gear (709) is fixedly connected to the proximal end of one end of the connecting shaft (704), and an arc-shaped rack (7010) located below the short arc groove (7022) and matching with the incomplete gear (709) is fixed on the side of the corresponding annular vertical partition (701), wherein the tooth of the incomplete gear (709) has a corresponding central angle between 90° and 180°.

7. A wastewater treatment system for a waste incineration power plant according to claim 2, characterized in that: The guide frame (708) comprises a plurality of guide rods (7081) that are movable in a vertical direction and pass through the vehicle body (707); a sleeve (7082) that is movably sleeved on the connecting shaft (704) is fixedly connected to the lower end of each guide rod (7081); a torsion spring (7083) is arranged in each sleeve (7082); one torsion arm of the torsion spring (7083) is connected to the sleeve (7082); and the other torsion arm of the torsion spring (7083) is connected to the connecting shaft (704); in a natural state, the arc-shaped slag scoop box (706) is in a horizontal posture.

8. A wastewater treatment system for a waste incineration power plant according to claim 2, characterized in that: The top of the annular vertical partition (701) is integrally formed with a flange (10); the vehicle body (707) comprises a vehicle plate (7071) radially arranged along the annular flotation tank (202); a first side plate (7072) and a second side plate (7073) are respectively fixedly connected at both ends of the vehicle plate (7071); Two first wheels (7074) are distributed on the first side plate (7072) and are located at the upper and lower sides of the corresponding flange (10), respectively. A connecting rod (7075) is fixedly connected to the outer side surface of the first side plate (7072), and a support platform is provided at the central axis of the annular air flotation tank (202). One end of the connecting rod (7075) away from the first side plate (7072) is rotatably connected to the support platform.

9. A wastewater treatment system for a waste incineration power plant according to claim 8, characterized in that: The second side plate (7073) is provided with a second wheel (7078) and a driving gear (7076) respectively located on the upper and lower sides of the corresponding flange (10); a gear ring (12) is fixedly connected to the bottom surface of one of the flanges (10); the driving gear (7076) is meshed with the gear ring (12); and a motor (7077) drivingly connected to the driving gear (7076) is mounted on the second side plate (7073).

10. A method for treating wastewater in a waste incineration power plant, applicable to the wastewater treatment system for a waste incineration power plant according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: The wastewater in the waste incineration power plant enters the preliminary treatment unit (1) and undergoes coarse screening; Step 2: The sewage after coarse screening enters the sedimentation treatment unit (2) for solid-liquid separation; Step 3: After solid-liquid separation, the wastewater enters the biochemical treatment unit (3) to use microorganisms to degrade organic matter in the wastewater; Step 4: The degraded sewage enters the filtration treatment unit (4) to remove tiny particles and microorganisms in the sewage; Step 5: disinfect the sewage after the above treatment through the disinfection treatment unit (5).

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