A sludge water treatment system and method for water purification treatment

Abstract

The present application relates to water purification treatment technical field, specifically for a kind of sludge water treatment system and method for water purification treatment, including sequence batch intermittent clarifier, sequence batch intermittent clarifier is used to receive from the backwashing water of water purification plant filter and after being intercepted by grating sludge water;The present application is by the efficient integration of the function of regulating, concentration and sludge discharge independently arranged in traditional sludge water disposal process in the same structure, form sequence batch intermittent clarifier, substantially improve the volume utilization of process system structure, significantly reduce the land area and investment cost.Meanwhile, by dynamically adjusting the water inlet mode of the clarifier, the increase of sludge and water during the high turbidity period of river water source and the impact load of concentrated drainage under special working conditions can be precisely matched without expanding the design scale, achieving the synergistic enhancement of treatment efficiency and system impact resistance.

Description

Technical Field

[0001] This invention relates to the field of water purification technology, specifically to a sludge treatment system and method for water purification. Background Technology

[0002] Water treatment plants generate various types of wastewater during the water production process, mainly including sludge discharge from flocculation and sedimentation tanks, backwash water and primary filtration water from filter beds, scum from flotation tanks, and membrane filtration cleaning wastewater. These wastewaters are collectively referred to as water treatment plant sludge discharge. It exhibits distinct water quality and quantity characteristics: its generation is intermittent, with significant shock loads but relatively small overall volume; its composition is relatively simple, mainly containing inorganic minerals, aluminum salts, and river microorganisms, with low levels of organic matter and nutrients, and no toxic substances such as heavy metals; the solid impurities are mostly destabilized flocculent particles with good settling properties.

[0003] Currently, the industry generally adopts the traditional "adjustment-concentration-equilibrium-dewatering" process for treating sludge discharge from water treatment plants, which is derived from the sludge concentration dewatering process route in water treatment. This process involves setting up an adjustment tank to balance the water quality and quantity, a concentration tank to increase the sludge solids content, a equilibrium tank to buffer sludge volume fluctuations, and finally, dewatering equipment to reduce the sludge volume.

[0004] However, during flood season, the volume of sludge discharge water surges and the sludge content skyrockets (the amount of oven-dried sludge can reach more than 10 times the normal value). The fixed treatment capacity of traditional processes cannot meet the peak operation demand, and continuous flow thickeners often suffer from a significant drop in treatment efficiency due to overload operation, and even problems such as sludge overflow occur. To address these issues, we propose a sludge discharge water treatment system and method for water purification to effectively solve the above-mentioned drawbacks. Summary of the Invention

[0005] The purpose of this invention is to provide a sludge treatment system and method for water purification, which solves the problem mentioned in the background art that the prior art cannot meet the peak operation requirements during flood season.

[0006] This invention is achieved through the following technical solution: a sludge treatment system for water purification, comprising:

[0007] A screen, the screen being used to intercept impurities in the sludge discharge water from the sedimentation tank of a water treatment plant;

[0008] A sequential batch intermittent clarification device, wherein the sequential batch intermittent clarification device is used to receive backwash water from the filter bed of a water purification plant and sludge water after being intercepted by a screen;

[0009] A balancing tank for receiving concentrated sludge from a sequencing batch clarifier;

[0010] A dewatering machine for dewatering concentrated sludge from a balancing tank;

[0011] A reuse tank for receiving supernatant from the sequencing batch clarifier;

[0012] The sequencing batch clarifier comprises at least three tank bodies arranged in an array, with an overflow weir between any two adjacent tank bodies; a skimmer is installed at one end of each tank body, and each skimmer is connected to the reuse tank via a pipeline; a sludge hopper is provided at the bottom of the other end of each tank body, and a gas-lift sludge discharge device is installed in each sludge hopper and connected to the balancing tank via a pipeline; a hydraulic reciprocating sludge scraping device is installed at the bottom of each tank body, and is used to collect sludge at the bottom of the tank body into the sludge hopper.

[0013] Optionally, the hydraulic reciprocating sludge scraping device comprises a rack slidingly connected to the tank body, and a hydraulic drive mechanism is installed on the tank body to reciprocate the rack along the length direction of the tank body.

[0014] A lifting mechanism is installed on the rack, and the execution end of the lifting mechanism is connected to a frame below the rack, a plurality of rotating shafts are rotatably connected to the frame at intervals along the length direction, and a scraper is fixed to each rotating shaft and arranged along the width direction of the tank body.

[0015] Optionally, a torsional spring is sleeved on each rotating shaft and located on both sides of the scraper, one torsional arm of each torsional spring is connected to the corresponding scraper, and the other torsional arm of each torsional spring is connected to the frame; when not subjected to external force, the scraper is in a vertical state under the action of the torsional spring.

[0016] A rotating drive mechanism corresponding to each rotating shaft is installed on the frame, and the rotating drive mechanism is used to apply external force to the corresponding rotating shaft to make the scraper in an inclined state.

[0017] Optionally, in the flood period working condition, when the frame moves towards the sludge hopper to scrape sludge, the lower edge of the scraper is in contact with the bottom of the tank; when the frame moves away from the sludge hopper to reset, the included angle between the scraper and the frame is 50°-70°.

[0018] In the non-flood period working condition, when the frame moves towards the sludge hopper to scrape sludge, the lower edge of the scraper is not in contact with the bottom of the tank; when the frame moves away from the sludge hopper to reset, the included angle between the scraper and the frame is 20°-40°.

[0019] Optionally, the rotating drive mechanism comprises a waterproof cover fixed to the side surface of the frame, a gear is fixed to the end of the rotating shaft and sleeved in the waterproof cover, and a rack is movably arranged in the waterproof cover and engaged with the gear.

[0020] A fixed cylinder is fixed inside the waterproof cover, which is aligned with the rack. A magnetic body is fixed at one end of the rack and slides inside the fixed cylinder. An electromagnet that cooperates with the magnetic body is fixed inside the fixed cylinder. A first spring is provided between the electromagnet and the magnetic body, and the first spring is always in a compressed state.

[0021] Optionally, a connecting rope is fixed to the end of the rack away from the magnet, and the end of the connecting rope away from the rack moves through the waterproof cover and is fixed to the frame;

[0022] During flood season, when the frame moves towards the sludge hopper to scrape sludge, the connecting rope is slack; when the frame moves away from the sludge hopper to reset, the electromagnet is energized and the connecting rope is taut.

[0023] During non-flood season operation, when the frame moves towards the sludge hopper to scrape sludge, the connecting rope is in a slack state, and the deformation in this slack state is greater than the deformation in the flood season operation; when the frame moves away from the sludge hopper to reset, the electromagnet is energized, and the connecting rope is in a taut state.

[0024] Optionally, the scraper is provided with an open cavity at the top, a negative pressure regulating plate slides in the cavity, and several second springs are installed in the cavity at the bottom of the negative pressure regulating plate, each second spring being always in a compressed state.

[0025] Under normal conditions, the upper end of the negative pressure regulating plate is located inside the cavity; under non-flood season conditions, when the frame moves away from the sludge hopper and resets, the upper end of the negative pressure regulating plate extends outside the cavity.

[0026] Optionally, slide rods are fixed on both sides of the negative pressure regulating plate, and strip holes are provided on both sides of the scraper for the corresponding slide rods to pass through; and adjusting grooves corresponding to each slide rod are provided on the side wall of the frame.

[0027] As the scraper rotates along the rotating shaft, the second compression spring causes the slide bar to always slide along the path of the adjusting groove.

[0028] Optionally, the adjusting groove includes a first arc-shaped groove and a second arc-shaped groove that are interconnected;

[0029] The center of the first arc-shaped groove is located on the axis of the rotating shaft, and the center of the second arc-shaped groove is located diagonally below the rotating shaft.

[0030] The present invention also provides a sludge discharge water treatment method, applicable to the above-mentioned sludge discharge water treatment system, including non-flood season operation and flood season operation;

[0031] The non-flood season operating conditions involve the following steps:

[0032] Step A1, Inlet Water Process Section;

[0033] The three pools operate in parallel, and the sludge-discharged water after being intercepted by the screen enters each pool until the preset high liquid level is reached.

[0034] Step A2, Precipitation process section;

[0035] Each tank is allowed to settle for 1 to 3 hours;

[0036] Step A3, Sludge Removal Process Section;

[0037] After settling, the hydraulic reciprocating sludge scraping device in each tank is started and operated; during the sludge scraping, the sludge is periodically pumped out by the air-lift sludge discharge device; the pumped-out concentrated sludge is discharged to the balance tank, and then mechanically dewatered by the dewatering machine.

[0038] Step A4, Drainage process section;

[0039] After completing step A3, the decanters in each tank collect the supernatant, which flows by gravity into the reuse tank and is then pumped back for reuse.

[0040] After drainage is complete, repeat steps A1 to A4;

[0041] The operating conditions during flood season involve the following steps:

[0042] Step B1, Inlet Water Process Section;

[0043] The three tanks operate in series. The sludge-laden water that has been filtered by the screen enters the tank at one end until it is full. Once full, the upper-layer treated water of that tank overflows through the overflow weir into the adjacent tank. This overflow process continues until all tanks are full.

[0044] Afterwards, the water inlet sequence is adjusted, and the sludge-removed water that has been intercepted by the screen enters the pool at the other end, and then flows into each pool in sequence through overflow; the water inlet sequence is rotated according to a preset cycle.

[0045] Step B2, sludge removal process section;

[0046] During the water intake period, the hydraulic reciprocating sludge scraping device in each tank operates continuously; during the sludge scraping period, the sludge is periodically pumped out by the air-lift sludge discharge device, and the pumped-out concentrated sludge is discharged to the balance tank, and then mechanically dewatered by the dewatering machine.

[0047] Step B3, Drainage process section;

[0048] In step B1, after all the tanks are full, the decanters in each tank collect the supernatant. The collected supernatant flows by gravity into the recycled water tank and is then pumped back for reuse.

[0049] After drainage is complete, repeat steps B1 to B3.

[0050] Compared with the prior art, the present invention provides a sludge discharge water treatment system and method for water purification, which has the following beneficial effects:

[0051] 1. This invention efficiently integrates the regulation, concentration, and sludge discharge functions—which are independently set up in traditional sludge treatment processes—into a single structure, forming a batch intermittent clarification device. This significantly improves the utilization rate of the structure's volume in the process system and substantially reduces land area and investment costs. Simultaneously, by dynamically adjusting the clarification device's influent mode (parallel operation during non-flood seasons and series operation during flood seasons), it can precisely adapt to the increased sludge volume during periods of high turbidity in river sources and the impact loads such as concentrated drainage under special operating conditions without expanding the design scale. This achieves a synergistic enhancement of treatment efficiency and system shock resistance.

[0052] 2. The hydraulic reciprocating sludge scraping device of the present invention, through the coordinated design of the frame, lifting mechanism, frame and scraper, can dynamically adjust the sludge scraping state of the scraper according to the working conditions: During the flood season, because the device is in continuous operation mode, the sludge layer at the bottom of the pool is relatively thin. At this time, the lifting mechanism makes the lower edge of the scraper in close contact with the bottom of the pool, which can thoroughly scrape off the loose sludge on the surface and avoid the formation of caking residue; During the non-flood season, after the pool has been left to settle for 1-3 hours, the sludge layer is relatively thick. The lifting mechanism controls the lower edge of the scraper to maintain a preset gap with the bottom of the pool, which can not only avoid the scraper directly cutting into the thick sludge layer and causing equipment overload, but also reduce the violent agitation of the settled sludge layer and ensure the clarity of the supernatant.

[0053] 3. This invention, through the coordinated operation of the rotating shaft, scraper, torsion spring, and rotating drive mechanism, can dynamically adjust the scraper reset state according to the working conditions: during flood season, when the scraper retracts and resets, the angle between the scraper and the frame is 50°-70°, and the small gap formed between the lower edge of the scraper and the bottom of the pool can not only prevent the sludge that has been accumulated from being brought back, but also use local water flow to guide the residual sludge to flow towards the sludge collection area; during non-flood season, when the scraper retracts and resets, the angle between the scraper and the frame is 20°-40°, and the gap between the lower edge of the scraper and the bottom of the pool is larger, which can prevent thick sludge from adhering to the scraper and being brought back.

[0054] 4. This invention, through the coordinated operation of the negative pressure regulating plate, sliding rod, strip hole, and regulating groove, can specifically solve the problem of insufficient negative pressure when the scraper resets during non-flood periods: when the scraper retracts and resets with a large gap between its lower edge and the bottom of the pool, the negative pressure regulating plate extends from inside the scraper, enhancing the local water flow velocity by compressing the water flow channel on the rear side of the scraper's movement direction, stabilizing and maintaining the required negative pressure, ensuring that the residual sludge at the bottom of the pool continues to flow towards the sludge collection area under the action of negative pressure, avoiding sludge retention caused by negative pressure attenuation due to excessive gaps, and improving the collection efficiency of thick sludge layers during non-flood periods. Attached Figure Description

[0055] Figure 1This is a flow chart of the sludge discharge water treatment process of the present invention;

[0056] Figure 2 This is a flowchart illustrating the operation of the batch intermittent clarification equipment of the present invention.

[0057] Figure 3 This is a plan view of the batch intermittent clarification device of the present invention;

[0058] Figure 4 This is a cross-sectional view of the batch intermittent clarification device of the present invention;

[0059] Figure 5 This is a schematic diagram of the frame of the present invention;

[0060] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0061] Figure 7 This is a schematic diagram of the scraper of the present invention;

[0062] Figure 8 for Figure 7 Enlarged view of point B in the middle;

[0063] Figure 9 This is a schematic diagram of the interior of the waterproof cover of the present invention;

[0064] Figure 10 This is a diagram showing the state of the scraper blade during non-flood season scraping mud according to the present invention;

[0065] Figure 11 This is a diagram showing the state of the scraper blade during non-flood season when it retracts and resets.

[0066] Figure 12 This is a diagram showing the state of the scraper blade during flood season when it is scraping mud.

[0067] Figure 13 This is a diagram showing the state of the scraper blade during flood season when it retracts and resets.

[0068] In the diagram: 1. Bar screen; 2. Sequencing batch intermittent clarification equipment; 21. Tank body; 22. Overflow weir; 23. Decanter; 24. Sludge hopper; 25. Air-lift sludge removal device; 26. Hydraulic reciprocating sludge scraper; 261. Frame; 262. Hydraulic drive mechanism; 263. Lifting mechanism; 264. Frame; 265. Rotating shaft; 266. Scraper; 3. Balance tank; 4. Dewatering machine; 5. Torsion spring; 6. Rotary drive mechanism; 601. Waterproof cover; 602. Gear; 603. Rack; 604. Fixed cylinder; 605. Magnetic body; 606. Electromagnet; 607. First spring; 608. Connecting rope; 7. Negative pressure regulating plate; 8. Sliding rod; 9. Strip hole; 10. Adjusting groove; 101. First arc groove; 102. Second arc groove; 11. Reclaimed water tank. Detailed Implementation

[0069] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Example 1: Please refer to Figures 1 to 13 A sludge treatment system for water purification includes: a bar screen 1, a sequential batch clarifier 2, a balancing tank 3, a dewatering machine 4, and a recycled water tank 11.

[0071] Specifically, the screen 1 is used to intercept large impurities (such as suspended particles with a diameter ≥ 5mm) in the sludge discharge water from the sedimentation tank of the water treatment plant. The sequencing batch clarifier 2 is used to receive backwash water from the filter tank of the water treatment plant and the sludge discharge water intercepted by the screen 1, realizing integrated treatment of water purification and sludge thickening. The balancing tank 3 is used to receive the thickened sludge from the sequencing batch clarifier 2 and temporarily store the thickened sludge, playing a role in buffering sludge volume fluctuations. The dewatering machine 4 is used to dewater the thickened sludge from the balancing tank 3, which can be a plate and frame filter press or a centrifugal dewatering machine to reduce the sludge moisture content. The reclaimed water tank 11 is used to receive the supernatant from the sequencing batch clarifier 2.

[0072] The sequencing batch intermittent clarification device 2 includes at least three tanks 21 arranged in an array (e.g., horizontally parallel or vertically connected in series). An overflow weir 22 is installed between adjacent tanks 21, the height of which is set according to the design liquid level difference to achieve automatic water flow switching between tanks 21. A decanter 23 is installed at one end of each tank 21, and each decanter 23 is connected to the recycled water tank 11 via a pipeline to collect the upper layer of clear liquid in the tank 21, avoiding disturbance of the lower layer of sludge. A sludge hopper 24 is installed at the bottom of each tank 21 to collect the sludge from the bottom. An air-lift sludge removal device 25 is installed in each sludge hopper 24, and each air-lift sludge removal device 25 is connected to the balance tank 3 via a pipeline. In this embodiment, the air-lift sludge discharge device 25 includes an air-lift sludge discharge main pipe 252 and several air pipes 251. One end of the air-lift sludge discharge main pipe 252 is connected to an external air source device (such as a Roots blower) to provide compressed air with stable pressure. The other end of the air-lift sludge discharge main pipe 252 is connected to each air pipe 251. The air outlet of each air pipe 251 extends to the bottom of the sludge hopper 24 (10-15 cm from the bottom of the hopper). By introducing compressed air, an air-sludge mixture is formed, and the concentrated sludge in the sludge hopper 24 is transported to the balance tank 3 using the air-lift principle.

[0073] To achieve automated operation control, each tank 21 is equipped with a level gauge 12 (such as an ultrasonic level gauge or a submersible level sensor) to monitor the water level in the tank 21 in real time. Its signal output is electrically connected to the control system, allowing for precise level control in conjunction with water inlet regulation (such as triggering a stop to water inlet or switching operating phases). Each decanter 23 has a turbidity meter 13 (such as a diffuse light turbidity meter) installed at its outlet to monitor the turbidity of the supernatant. When the turbidity exceeds a preset threshold, the control system can adjust the decanting depth or pause drainage to ensure the quality of the recycled water. Each tank 21 has an electric valve 14 (such as an electric butterfly valve) installed at its inlet. The electric valve 14 is linked to the level gauge 12. During non-flood seasons, it independently controls the water inlet flow of each tank 21 when operating in parallel. During flood seasons, it switches the water flow sequence by adjusting the valve opening, precisely adapting to the water inlet requirements under different operating conditions.

[0074] In addition, a hydraulic reciprocating sludge scraper 26 is installed at the bottom of each pool 21. The hydraulic reciprocating sludge scraper 26 is used to collect the sludge at the bottom of the pool into the sludge hopper 24.

[0075] With the above design, the system can adapt to different operating conditions by dynamically switching the operating modes of the pools 21: During non-flood seasons, each pool 21 operates in parallel, simultaneously receiving and processing sludge discharge water, achieving multi-unit parallel processing to improve treatment efficiency under normal operating conditions. During flood seasons, each pool 21 switches to series operation mode, with sludge discharge water overflowing from the first pool 21 through the overflow weir 22 to subsequent pools 21 until all pools 21 are full. This enhances the settling effect of high-turbidity sludge water by extending the water flow path and increasing the residence time. This design can accurately match the increase in sludge water during high-turbidity periods of river sources and the concentrated drainage impact load under special operating conditions without expanding the equipment design scale. While ensuring stable treatment efficiency, it significantly improves the system's impact resistance, achieving synergistic enhancement of both.

[0076] During non-flood seasons, the tank 21 needs to undergo a 1-3 hour settling process. After the sludge particles have settled sufficiently, a thick sludge layer (usually 20-30 cm thick) will form at the bottom of the tank. During flood seasons, in order to avoid the continuous accumulation of high-turbidity mud and water affecting the treatment efficiency, the hydraulic reciprocating sludge scraper 26 starts continuous operation mode during the water intake stage. By scraping off the settled sludge in real time, the sludge layer at the bottom of the tank is kept thin (usually controlled at 5-10 cm thick).

[0077] To address the significant difference in silt thickness (thick layer vs. thin layer) under the two aforementioned working conditions, traditional silt scraping devices, due to their non-adjustable height, suffer from overload during non-flood seasons when the scraper cuts too deeply into the silt. During flood seasons, the excessive gap between the lower edge of the scraper and the pool bottom hinders the removal of thin silt layers. Therefore, this invention features a specially designed hydraulic reciprocating silt scraping device 26, with the specific structure and effects as follows:

[0078] The hydraulic reciprocating sludge scraper 26 includes a frame 261 (made of stainless steel, with a slider at the bottom that engages with a guide rail on the side wall of the pool body) slidably connected within the pool body 21. A hydraulic drive mechanism 262 is mounted on the pool body 21 to reciprocate the frame 261 along its length. In this embodiment, the hydraulic drive mechanism 262 can use a hydraulic cylinder to drive the frame 261 to reciprocate linearly along the length of the pool body 21. A lifting mechanism 263 (such as an electric push rod or a hydraulic cylinder) is mounted on the frame 261. The actuating end of the lifting mechanism 263 is connected to a frame 264 located below the frame 261. The vertical distance between the frame 264 and the bottom of the pool can be adjusted by extending or retracting the lifting mechanism 263. Several rotating shafts 265 are rotatably connected at intervals along the length of the frame 264, and scrapers 266 arranged along the width of the pool body 21 are fixed on each rotating shaft 265.

[0079] Torsion springs 5 ​​are fitted on each rotating shaft 266, located on both sides of the scraper 266. One torsion arm of each torsion spring 5 is connected to the corresponding scraper 266, and the other torsion arm is connected to the frame 264. When not subjected to external system force, the scraper 266 is kept vertical under the action of the torsion springs 5, ensuring the stability of the initial position. A rotary drive mechanism 6 corresponding to each rotating shaft 265 is installed on the frame 264. The rotary drive mechanism 6 is used to apply external system force to the corresponding rotating shaft 265, so that the scraper 266 is tilted.

[0080] During flood season, the system controls the thickness of the sludge layer at the bottom of the tank to be 5-10 cm by scraping away settled sludge in real time. When the frame 264 moves towards the sludge hopper 24 to scrape sludge, the lifting mechanism 263 drives the frame 264 downward, so that the lower edge of the scraper 266 contacts the bottom of the tank, thereby enabling efficient scraping of the thin layer of sludge. When the frame 264 moves away from the sludge hopper 24 to reset, the rotary drive mechanism 6 drives the rotary shaft 265 to rotate, so that the angle between the scraper 266 and the frame 264 is 50°-70°, and the lower edge of the scraper 266 forms a small gap of 6-10 mm with the bottom of the tank. This gap is smaller than the average particle size of the sludge (15-20 μm), which can prevent the accumulated sludge from being carried back to the scraping area (sludge return amount ≤0.1 kg / m²), and can also push the remaining fine sludge particles to the sludge hopper 24 through the local vortex formed by the movement of the scraper 266.

[0081] Under non-flood season conditions, after 1-3 hours of settling, the sludge layer reaches a thickness of 20-30 cm. When the frame 264 moves towards the sludge hopper 24 to scrape sludge, the lifting mechanism 263 retracts, raising the frame 264. The lower edge of the scraper 266 does not contact the bottom of the tank, forming a large gap of 30-60 mm (1 / 5-1 / 3 of the sludge thickness). This avoids overloading the equipment by directly cutting into the thick sludge layer and reduces disturbance to the sedimentation layer (the turbidity increase of the supernatant is ≤5 NTU). When the frame 264 moves away from the sludge hopper 24 to reset, the rotary drive mechanism 6 drives the rotary shaft 265 to rotate, so that the angle between the scraper 266 and the frame 264 is 20°-40°. This prevents thick sludge from adhering to the scraper 266, ensuring no secondary pollution during the reset process. The sludge collection rate is increased to over 92% within a single scraping cycle.

[0082] The rotary drive mechanism 6 is described below:

[0083] The rotary drive mechanism 6 includes a waterproof cover 601 fixed to the side of the frame 264. A gear 602 is fixedly sleeved at the end of the rotating shaft 265 and located inside the waterproof cover 601. A rack 603 is movably disposed inside the waterproof cover 601 and meshes with the gear 602. The reciprocating movement of the rack 603 can directly drive the gear 602 to rotate, thereby driving the rotating shaft 265 and the scraper 266 to rotate synchronously.

[0084] A fixed cylinder 604, which is aligned with the rack 603, is fixed inside the waterproof cover 601. A magnetic body 605 (made of neodymium iron boron strong magnetic material) is fixed at one end of the rack 603 and slides inside the fixed cylinder 604. An electromagnet 606, which cooperates with the magnetic body 605, is fixed inside the fixed cylinder 604. A first spring 607 is provided between the electromagnet 606 and the magnetic body 605. The first spring 607 is always in a compressed state.

[0085] When the electromagnet 606 is de-energized, the elastic force of the first spring 607 pushes the rack 603 back to its initial position. At this time, the gear 602 drives the scraper 266 to remain vertical. When the electromagnet 606 is energized, the magnetic force it generates overcomes the spring force to attract the magnetic body 605, driving the rack 603 to move axially along the fixed cylinder 604, and then causing the scraper 266 to rotate to an inclined state through gear transmission.

[0086] To precisely control the tilt angle of the scraper 266 under different working conditions, a connecting rope 608 is fixed to the end of the rack 603 away from the magnet 605. The end of the connecting rope 608 away from the rack 603 moves through the sealing hole of the waterproof cover 601 and is fixed to the frame 261. This design limits the maximum movement distance of the rack 603 by the length of the connecting rope 608, thus achieving mechanical limiting of the scraper 266 angle.

[0087] During flood season, the frame 264 is relatively low (close to the bottom of the tank). When the frame 264 moves towards the sludge hopper 24 to scrape sludge, the connecting rope 608 is slack (slack ≤ 10mm), which does not affect the vertical scraping of sludge by the scraper. When the frame 264 moves away from the sludge hopper 24 to reset, the electromagnet 606 is energized, and the connecting rope 608 is taut, limiting the movement distance of the rack 603. This keeps the angle between the scraper 266 and the frame 264 stable at 50°-70°, ensuring that the lower edge of the scraper 266 forms a small gap of 5-8mm with the bottom of the tank.

[0088] During non-flood season operations, the frame 264 is at a relatively high height (far from the bottom of the tank). When the frame 264 moves towards the sludge hopper 24 to scrape sludge, the connecting rope 608 is in a slack state, and the deformation in this slack state is greater than the deformation during flood season operations (slack amount reaches 20-30mm), avoiding interference and keeping the scraper 266 in a slightly raised state. When the frame 264 moves away from the sludge hopper 24 to reset, the electromagnet 606 is energized, and the connecting rope 608 is taut, limiting the movement distance of the rack 603, so that the angle between the scraper 266 and the frame 264 is stably maintained at 20°-40°, adapting to the gap requirements of thick sludge layers.

[0089] Employing a dual control system of "electromagnetic drive + mechanical limit," the scraper 266 angle adjustment accuracy reaches ±1°, ensuring the stability of the gap size under different working conditions. Furthermore, the linkage design between the connecting rope 608 and the frame 264 height enables "one mechanism to adapt to two working conditions," allowing angle switching without additional switching components, with a response time ≤0.5s, meeting the rapid switching requirements between intermittent and continuous operation.

[0090] Under non-flood season conditions, when scraper 266 retracts and resets, the angle between scraper 266 and frame 264 remains stable at 20°-40°. This means scraper 266 needs to rotate 50-70° from a vertical position to accommodate a 20-30cm thick sludge layer (avoiding the re-bringing of adhering thick sludge). However, this angle leads to a larger gap between scraper 266 and the bottom of the tank, causing two key problems: First, the water flow channel behind scraper 266 widens due to the increased gap, causing the water flow velocity to drop from 0.3m / s to below 0.1m / s, resulting in a local negative pressure decrease of more than 60%. Second, insufficient negative pressure causes the sludge to lose its driving force to flow to sludge hopper 24, and about 10%-15% of fine sludge particles will remain at the bottom of the tank, which can easily lead to caking over time.

[0091] To solve the above problems, in another embodiment of this application, a cavity with an open upper end is provided in the scraper 266, a negative pressure regulating plate 7 slides in the cavity, and a plurality of second springs are installed in the cavity at the bottom of the negative pressure regulating plate 7, each of the second springs being always in a compressed state.

[0092] Under normal conditions, the upper end of the negative pressure regulating plate 7 is located inside the cavity. Under non-flood conditions, when the frame 264 moves away from the sludge hopper 24 and resets, the upper end of the negative pressure regulating plate 7 extends outside the cavity. The local water flow velocity is enhanced through the water flow channel on the rear side of the compression scraper 266, which stabilizes and maintains the required negative pressure. This ensures that the residual sludge at the bottom of the pool continues to flow to the sludge collection area under the action of negative pressure, avoiding sludge retention caused by negative pressure attenuation due to excessive gaps, and improving the collection efficiency of thick sludge during non-flood periods.

[0093] Specifically, slide rods 8 are fixed on both sides of the negative pressure regulating plate 7, and strip holes 9 are provided on both sides of the scraper 266 for the corresponding slide rods 8 to pass through; and adjusting grooves 10 corresponding to each slide rod 8 are provided on the side wall of the frame 264.

[0094] When the scraper 266 rotates along the rotating shaft 265, the second compression spring causes the slide bar 8 to always slide along the path of the adjusting groove 10. The adjusting groove 10 includes a first arc-shaped groove 101 and a second arc-shaped groove 102 that are interconnected; the center of the first arc-shaped groove 101 is located on the axis of the rotating shaft 265, and the center of the second arc-shaped groove 102 is located diagonally below the rotating shaft 265.

[0095] With the above design, during the flood season, when the scraper 266 rotates, the slide rod 8 slides within the first arc-shaped groove 101, and the negative pressure regulating plate 7 remains in a retracted state. When the scraper 266 continues to rotate (outside of the flood season), the slide rod 8 enters the second arc-shaped groove 102, and under the thrust of the second spring and the guiding action of the groove wall, the negative pressure regulating plate 7 extends 20-30mm from the cavity.

[0096] During non-flood seasons, when the scraper 266 retracts and resets, the extended negative pressure regulating plate 7 can compress the cross-sectional area of ​​the water flow channel by 40%–50%, causing the local flow velocity to rise to 0.25–0.3 m / s and the negative pressure to recover to more than 90% of the design value. This ensures that the sludge flows directionally towards the sludge hopper 24 under the drive of the water flow, reducing the sludge retention rate from 10%–15% to below 3%. Simultaneously, the extension of the negative pressure regulating plate 7 automatically adapts to the angle of the scraper 266 without requiring additional power, achieving dynamic compensation of negative pressure under large-angle operating conditions. This balances the anti-backflow function of thick sludge layers with sludge collection efficiency.

[0097] Example 2: This example proposes a sludge discharge water treatment method, which is applicable to the sludge discharge water treatment system in Example 1, including non-flood season operation and flood season operation.

[0098] The non-flood season operating conditions involve the following steps:

[0099] Step A1, Inlet Water Process Section;

[0100] The three pools 21 operate in parallel. The sludge water intercepted by the grid 1 enters each pool 21 until the preset high liquid level is reached.

[0101] Step A2, Precipitation process section;

[0102] Each tank is left to settle for 1 to 3 hours, forming a sludge layer 20 to 30 cm thick.

[0103] Step A3, Sludge Removal Process Section;

[0104] After settling, the hydraulic reciprocating sludge scraping device 26 in each tank 21 is started and operated; during the sludge scraping, the sludge is periodically pumped out by the air-lift sludge discharge device 25; the pumped-out concentrated sludge is discharged to the balance tank 3, and then mechanically dewatered by the dewatering machine 4.

[0105] When scraping the sludge forward, the lifting mechanism 263 retracts to raise the frame 264, and the lower edge of the scraper 266 maintains a gap of 20-50mm with the bottom of the pool (without contacting the bottom of the pool), so as to avoid cutting into the thick sludge layer and causing equipment overload, while reducing disturbance to the sedimentation layer;

[0106] When retracting and resetting, the rotary drive mechanism 6 drives the rotary shaft 265 to rotate, so that the angle between the scraper 266 and the frame 264 is maintained at 20°-40°; at this time, the negative pressure regulating plate 7 extends out from the cavity of the scraper 266, compresses the water flow channel to maintain negative pressure, and ensures that the thick layer of sludge flows directionally to the sludge hopper 24.

[0107] Step A4, Drainage process section;

[0108] After completing step A3, the decanters 23 in each tank 21 collect the supernatant. The collected supernatant flows by gravity into the recycled water tank 11 and is then pumped back for reuse.

[0109] After drainage is complete, repeat steps A1 to A4.

[0110] The operating conditions during flood season involve the following steps:

[0111] Step B1, Inlet Water Process Section;

[0112] The three pools 21 are connected in series. The sludge water intercepted by the screen 1 enters the pool 21 located at one end until the pool 21 is full. After it is full, the upper layer of treated water in the pool 21 overflows into the adjacent pool 21 through the overflow weir 22. This overflow process continues until all pools 21 are full.

[0113] Afterwards, the water inlet sequence is adjusted, and the sludge-removed water that has been intercepted by the screen 1 enters the pool 21 located at the other end, and then enters each pool 21 in sequence through overflow; the water inlet sequence is rotated in sequence according to a preset cycle (such as every 2 hours);

[0114] Step B2, sludge removal process section;

[0115] During the water intake period, the hydraulic reciprocating sludge scraping device 26 in each tank 21 operates continuously; during the sludge scraping period, the sludge is periodically pumped out by the air-lift sludge discharge device 25, and the pumped-out concentrated sludge is discharged to the balance tank 3, and then mechanically dewatered by the dewatering machine 4.

[0116] When scraping the mud forward, the lifting mechanism 263 extends to lower the frame 264, and the lower edge of the scraper 266 comes into close contact with the bottom of the pool to thoroughly scrape off the thin layer of silt 5-10cm thick and avoid residual caking.

[0117] When retracting and resetting, the rotary drive mechanism 6 drives the scraper 266 to maintain an angle of 50°-70° with the frame 264. The lower edge of the scraper 266 forms a small gap of 5-8mm with the bottom of the pool, which not only prevents the return of the accumulated sludge, but also uses the water flow disturbance in the gap to guide the residual fine sludge to the sludge hopper 24, and the amount of residual sludge is controlled below 0.5kg / m².

[0118] Step B3, Drainage process section;

[0119] In step B1, after all the tanks 21 are full, the decanters 23 in each tank 21 collect the supernatant. The collected supernatant flows by gravity into the recycled water tank 11 and is pumped back for reuse.

[0120] After drainage is complete, repeat steps B1 to B3.

[0121] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0122] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sludge treatment system for water purification, characterized in that, include: A screen, the screen being used to intercept impurities in the sludge discharge water from the sedimentation tank of a water treatment plant; A sequential batch intermittent clarification device, wherein the sequential batch intermittent clarification device is used to receive backwash water from the filter bed of a water purification plant and sludge water after being intercepted by a screen; A balancing tank for receiving concentrated sludge from a sequencing batch clarifier; A dewatering machine for dewatering concentrated sludge from a balancing tank; A recycled water tank for receiving supernatant from a sequencing batch clarifier; The sequential batch clarification equipment includes at least three tanks arranged in an array, with an overflow weir between adjacent tanks. A decanter is installed at one end of each tank, and each decanter is connected to a recycled water tank via a pipeline. A sludge hopper is located at the bottom of each tank at the other end, and an air-lift sludge removal device is installed in each sludge hopper, connected to a balance tank via a pipeline. A hydraulic reciprocating sludge scraper is installed at the bottom of each tank to collect sludge from the bottom of the tank into the sludge hopper. During non-flood seasons, the three pools operate in parallel; during flood seasons, they operate in series. The hydraulic reciprocating sludge scraper includes a frame slidably connected to the pool body, and a hydraulic drive mechanism installed on the pool body for reciprocating motion of the frame along the length of the pool body. A lifting mechanism is installed on the frame. The execution end of the lifting mechanism is connected to a frame located below the frame. Several rotating shafts are rotatably connected to the frame at intervals along the length direction. A scraper is fixed on each rotating shaft along the width direction of the pool. Each rotating shaft is fitted with a torsion spring located on both sides of the scraper. One torsion arm of each torsion spring is connected to the corresponding scraper, and the other torsion arm of each torsion spring is connected to the frame. When not subjected to external force, the scraper is kept in a vertical position by the action of the torsion spring. A rotary drive mechanism corresponding to each rotating shaft is installed on the frame. The rotary drive mechanism is used to apply external force to the corresponding rotating shaft so that the scraper is tilted. During flood season, when the frame moves towards the sludge hopper to scrape sludge, the lower edge of the scraper contacts the bottom of the tank; when the frame moves away from the sludge hopper to reset, the angle between the scraper and the frame is 50°-70°. During non-flood season operation, when the frame moves towards the sludge hopper to scrape sludge, the lower edge of the scraper does not contact the bottom of the tank; when the frame moves away from the sludge hopper to reset, the angle between the scraper and the frame is 20°-40°. The scraper has an open cavity at the top, a negative pressure regulating plate slides in the cavity, and several second springs are installed at the bottom of the negative pressure regulating plate in the cavity. Each second spring is always in a compressed state. Under normal conditions, the upper end of the negative pressure regulating plate is located inside the cavity; under non-flood season conditions, when the frame moves away from the sludge hopper and resets, the upper end of the negative pressure regulating plate extends outside the cavity. The negative pressure regulating plate is fixed with sliding rods on both sides, and strip holes are opened on both sides of the scraper for the corresponding sliding rods to pass through; the side wall of the frame is provided with adjusting grooves corresponding to each sliding rod. When the scraper rotates along the rotating shaft, the second compression spring causes the slide bar to always slide along the path of the adjusting groove. The adjusting groove includes a first arc-shaped groove and a second arc-shaped groove that are interconnected. The center of the first arc-shaped groove is located on the axis of the rotating shaft, and the center of the second arc-shaped groove is located diagonally below the rotating shaft.

2. The sludge treatment system for water purification according to claim 1, characterized in that: The rotary drive mechanism includes a waterproof cover fixed to the side of the frame, a gear located inside the waterproof cover is fixedly sleeved at the end of the rotary shaft, and a rack that meshes with the gear is movably arranged inside the waterproof cover. A fixed cylinder is fixed inside the waterproof cover, which is aligned with the rack. A magnetic body is fixed at one end of the rack and slides inside the fixed cylinder. An electromagnet that cooperates with the magnetic body is fixed inside the fixed cylinder. A first spring is provided between the electromagnet and the magnetic body, and the first spring is always in a compressed state.

3. A sludge treatment system for water purification according to claim 2, characterized in that: The end of the rack away from the magnet is fixed with a connecting rope, and the end of the connecting rope away from the rack moves through the waterproof cover and is fixed to the frame. During flood season, when the frame moves towards the sludge hopper to scrape sludge, the connecting rope is slack; when the frame moves away from the sludge hopper to reset, the electromagnet is energized and the connecting rope is taut. During non-flood season operation, when the frame moves towards the sludge hopper to scrape sludge, the connecting rope is in a slack state, and the deformation in this slack state is greater than the deformation in the flood season operation; when the frame moves away from the sludge hopper to reset, the electromagnet is energized, and the connecting rope is in a taut state.

4. A method for treating sludge discharge water, applicable to the sludge discharge water treatment system according to any one of claims 1-3, characterized in that, This includes operating conditions during non-flood seasons and operating conditions during flood seasons; The non-flood season operating conditions involve the following steps: Step A1, Inlet Water Process Section; The three pools operate in parallel, and the sludge-discharged water after being intercepted by the screen enters each pool until the preset high liquid level is reached. Step A2, Precipitation process section; Each tank is allowed to settle for 1 to 3 hours; Step A3, Sludge Removal Process Section; After settling, the hydraulic reciprocating sludge scraping device in each tank is started and operated; during the sludge scraping, the sludge is periodically pumped out by the air-lift sludge discharge device; the pumped-out concentrated sludge is discharged to the balance tank, and then mechanically dewatered by the dewatering machine. Step A4, Drainage process section; After completing step A3, the decanters in each tank collect the supernatant, which flows by gravity into the reuse tank and is then pumped back for reuse. After drainage is complete, repeat steps A1 to A4; The operating conditions during flood season involve the following steps: Step B1, Inlet Water Process Section; The three tanks operate in series. The sludge-laden water that has been filtered by the screen enters the tank at one end until it is full. Once full, the upper-layer treated water of that tank overflows through the overflow weir into the adjacent tank. This overflow process continues until all tanks are full. Afterwards, the water inlet sequence is adjusted, and the sludge-removed water that has been intercepted by the screen enters the pool at the other end, and then flows into each pool in sequence through overflow; the water inlet sequence is rotated according to a preset cycle. Step B2, sludge removal process section; During the water intake period, the hydraulic reciprocating sludge scraping device in each tank operates continuously; during the sludge scraping period, the sludge is periodically pumped out by the air-lift sludge discharge device, and the pumped-out concentrated sludge is discharged to the balance tank, and then mechanically dewatered by the dewatering machine. Step B3, Drainage process section; In step B1, after all the tanks are full, the decanters in each tank collect the supernatant. The collected supernatant flows by gravity into the recycled water tank and is then pumped back for reuse. After drainage is complete, repeat steps B1 to B3.

Images