A pre-sedimentation tank sedimentation sludge treatment system

Abstract

The application provides a pre-sedimentation tank sediment treatment system, which comprises a lifting pump, a dregs filtering device, a first cyclone, and a mortar pool, wherein the mortar pool comprises a first partition cavity and a second partition cavity, the bottom of the first partition cavity is provided with a first sand discharge screw rod, the bottom of the second partition cavity is provided with a second sand discharge screw rod, and the first sand discharge screw rod and the second sand discharge screw rod are both used for conveying the bottom sediments to a downstream sand discharge tank; the second partition cavity is provided with a water outlet on the side, the height of the water outlet is higher than that of the second sand discharge screw rod, and the water outlet is used for conveying water to a downstream municipal pipeline. The implementation of the application can effectively realize dregs isolation, fine sand preliminary recovery and clarified water stable discharge, provides a reliable front-end treatment for mud sand resource utilization, and improves resource utilization rate.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, specifically to a pre-sedimentation tank sedimentation sludge and sand treatment system. Background Technology

[0002] Pre-sedimentation tanks in water treatment plants are primarily used to remove coarse-grained sediments such as silt and gravel from raw water, reducing the load on subsequent treatment units and ensuring stable operation. During operation, a mixture of silt and sand continuously accumulates at the bottom of the tank. Traditionally, this is done by gravity or mechanical sludge removal followed by concentration and dewatering to form a sludge cake with a moisture content of 60%–80%, which is then sent to a landfill for disposal. However, this sediment is not simply waste; its composition mainly includes organic residues (such as leaves and twigs), a high proportion of inorganic fine sand (particle size mostly above 50 µm), and a small amount of clay. In most cases, the sludge cake is directly used for landfill.

[0003] Actual analysis revealed that the sediment slurry at the bottom of the pre-sedimentation tank mainly consists of slag and impurities (such as leaves and twigs), inorganic fine sand, and clay, with a high content of inorganic fine sand. If the slurry discharged from the pre-sedimentation tank is treated and then directly used for landfill, it will consume landfill volume and waste usable inorganic fine sand resources.

[0004] Therefore, there is an urgent need to develop a technical solution that can reduce the volume and recycle the sediment in the pre-sedimentation tank. Summary of the Invention

[0005] In view of the above-mentioned problems in the prior art, the purpose of this application is to provide a pre-sedimentation tank sedimentation and sand treatment system to solve the problems of incomplete cleaning of debris and low recovery rate of resources such as fine sand in the pre-sedimentation tank of waterworks in the prior art.

[0006] To solve the above-mentioned technical problems, the specific technical solution of this application is as follows: This application provides a pre-sedimentation tank sedimentation sludge and sand treatment system, including: The booster pump is connected at one end to the sedimentation tank of the waterworks and at the other end to the inlet of the scum filter device, and is used to transfer the sediment in the sedimentation tank to the scum filter device. The other end of the scum filtration device is connected to the first hydrocyclone, which is used to filter objects larger than a preset first size in the sediment and to transfer the filtered sediment to the first hydrocyclone. The first hydrocyclone has a first outlet connected to a first compartment of the slurry tank and a second outlet connected to a second compartment of the slurry tank. It is used to transport sediments with a gravity greater than centrifugal force to the first compartment through the first outlet and to transport sediments with a gravity less than or equal to centrifugal force to the second compartment through the second outlet. The mortar tank includes: a first compartment and a second compartment, wherein a first sand-discharging screw is provided at the bottom of the first compartment and a second sand-discharging screw is provided at the bottom of the second compartment, and both the first and second sand-discharging screws are used to transport the bottom sediment to the downstream sand-discharging box; The second compartment has a water outlet on its side, which is higher than the second sand discharge screw. The water outlet is used to transport water to the downstream municipal pipeline.

[0007] Optionally, a sawtooth weir is provided in the mortar pool, the sawtooth weir is connected to the outlet and is located upstream of the outlet.

[0008] Optionally, a second hydrocyclone is provided upstream of the sand discharge box, which is connected to the output end of the first sand discharge screw and the output end of the second sand discharge screw. The second hydrocyclone is used to separate the sediments transported by the first sand discharge screw and the second sand discharge screw. The second hydrocyclone transports sediments with gravity greater than centrifugal force to the sand discharge box.

[0009] Optionally, the system further includes: an inclined conveying screw, the conveying screw being located downstream of the sand discharge box, and the end of the conveying screw closer to the sand discharge box being lower than the other end.

[0010] Optionally, it also includes: a scum pressing device, which is located downstream of the scum filtration device and is used to press and dehydrate the filter material filtered by the scum filtration device.

[0011] Optionally, the bottom of both the first and second cavities is V-shaped.

[0012] Optionally, the particle size range of the second hydrocyclone is ≥50µm.

[0013] Optionally, an inclined separation plate is provided in the second compartment, with one end of the separation plate near the water outlet being higher than the other end.

[0014] Optionally, both the first hydrocyclone and the second hydrocyclone are conical hydrocyclones, and the separation particle size of the second hydrocyclone is smaller than that of the first hydrocyclone.

[0015] The pre-sedimentation tank sedimentation sludge treatment system provided in this application uses a lift pump to transport the sludge from the pre-sedimentation tank to a scum filtration device to remove large-sized scum and prevent it from interfering with subsequent treatment. The filtered sludge enters the first hydrocyclone, where centrifugal sedimentation separates the heavy fine sand from the light phase mud-water, and discharges them into the first and second compartments of the slurry tank, respectively. Both compartments are equipped with sand discharge screws at the bottom to achieve automatic collection and continuous discharge of settled sand, while the high-level outlet of the second compartment only allows supernatant overflow to avoid disturbing the bottom sediment. This system effectively achieves scum isolation, preliminary recovery of fine sand, and stable discharge of clarified water, providing a reliable front-end treatment for sludge resource utilization and improving resource utilization efficiency.

[0016] To make the above and other objects, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a pre-sedimentation tank sedimentation sludge treatment system according to an embodiment of this application is shown; Figure 2 This invention provides a schematic diagram of the structure of another pre-sedimentation tank sedimentation sludge treatment system according to an embodiment of the present application. 1-Boost pump; 2-Scum filtration device; 3-First hydrocyclone; 4-First septum; 5-Second diaphragm; 61 - First row of sand-carrying screws; 62 - Second row of sand-carrying screws; 7-Sawtooth weir; 8-Outlet; 9-Second hydrocyclone; 10-Scum pressing device; 11-Separation plate; 12-Sand discharge screw motor; 13-Sandbox; 14-Conveyor screw. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0021] To address the aforementioned problems, this application provides a pre-sedimentation tank sediment sludge resource utilization system, aiming to solve the resource waste and environmental burden caused by the direct landfilling of sludge from traditional waterworks pre-sedimentation tanks. This system achieves efficient separation and resource utilization of sludge, fine sand, and clarified water through a multi-stage separation process. The pre-sedimentation tank sediment sludge resource utilization system includes components such as a lift pump, a scum filter, a first hydrocyclone, a slurry tank, a first sand discharge screw, a second sand discharge screw, and a sand discharge box.

[0022] Specifically, one end of the booster pump is connected to the sludge discharge port at the bottom of the pre-sedimentation tank of the waterworks, and the other end is connected to the inlet of the scum filter device. After the pre-sedimentation tank completes its periodic sludge discharge, the sediment mixture (with a water content typically higher than 90%) enters the integrated pumping station by gravity or mechanical means, and is then pressurized and transported to the scum filter device by the booster pump. The scum filter device has a filtration accuracy of 1~3 mm and operates at a pressure of 0.1~0.3 MPa. It can effectively trap large-sized organic or light impurities such as leaves, twigs, and plastic fragments. The filtered sediment, free of large scum pieces, enters the first hydrocyclone downstream. The first hydrocyclone has a conical vortex structure, with its first outlet (bottom outlet) connected to the first compartment of the slurry tank, and its second outlet (overflow outlet) connected to the second compartment. Under centrifugal force, heavier sediments (particle size ≥ 50 µm) sink along the tank wall due to gravity exceeding centrifugal force and are discharged from the first outlet into the first compartment; while lighter slurry containing fine particles enters the second compartment from the overflow outlet. The slurry tank is a box-like structure, internally divided into a first compartment and a second compartment by a partition. Both compartments have a V-shaped bottom, and each is equipped with a sand-discharging screw 6 (first sand-discharging screw and second sand-discharging screw). The screws rotate continuously at low speed, pushing the sediment deposited at the bottom of the V-shape to one end of the tank. A conveying screw or... Pump body, through conveyor screw or The pump pushes the sediment to the downstream sediment flushing box.

[0023] The second chamber has an outlet on its side wall, positioned higher than the top of the second sand-discharging screw, ensuring that only the supernatant overflows, avoiding disturbance of the bottom sediment. This overall structure achieves preliminary separation of the mud-sand mixture: large slag is pre-filtered, coarse sand settles in the first chamber, fine sand is further separated in the second chamber, and clarified water is discharged stably. Both the first and second sand-discharging screws are driven by sand-discharging screw motors.

[0024] Based on the above embodiments, in one embodiment of this specification, a sawtooth weir is provided in the mortar pool, the sawtooth weir is connected to the outlet and is located upstream of the outlet. 。 In practice, the sawtooth weir is installed at the top of the second compartment near the outlet side. The weir plate is in the shape of continuous triangular teeth with a consistent tooth height. The elevation of the weir top is slightly lower than the top of the compartment but significantly higher than the installation height of the second sand-discharging screw. When the liquid level in the second compartment rises to the top of the sawtooth weir, the clarified water overflows evenly from each tooth opening, enters the collection tank, and then flows into the municipal sewage network.

[0025] The sawtooth weir in the embodiments of this specification can effectively balance the outflow velocity, stabilize the hydraulic load, and prevent the outflow from disturbing the fine sand that has settled at the bottom, thereby significantly improving the clarity of the outflow. At the same time, uniform overflow helps to maintain the stability of the liquid level in the second compartment, providing good hydraulic conditions for inclined plate sedimentation and further improving the fine sand collection efficiency.

[0026] Based on the above embodiments, in one embodiment of this specification, a second hydrocyclone is provided upstream of the sand discharge box, which is connected to the output end of the first sand discharge screw and the output end of the second sand discharge screw. The second hydrocyclone is used to separate the sediments transported by the first sand discharge screw and the second sand discharge screw. The second hydrocyclone transports sediments with gravity greater than centrifugal force to the sand discharge box.

[0027] In practice, the two sand-containing slurries (from the first and second compartments of the slurry tank, respectively) are merged through pipelines and then pumped or flowed by gravity into the second hydrocyclone. This hydrocyclone is also a conical structure, but smaller in size than the first hydrocyclone, and is specifically designed for fine final separation.

[0028] In specific implementations, the two sand streams can be processed centrally, avoiding redundant resource investment caused by setting up separate dewatering equipment; at the same time, mud with lower sand concentration but finer particle size can be efficiently recovered, ensuring that the overall fine sand recovery rate of the system is maximized.

[0029] Based on the above embodiments, in one embodiment of this specification, a second hydrocyclone is provided upstream of the sand discharge box. This second hydrocyclone is connected to the output ends of both the first and second sand discharge screws. The second hydrocyclone is used to further separate the sediments transported by the first and second sand discharge screws.

[0030] Specifically, when the sediment mixture flows into the second hydrocyclone, particles of different sizes and densities are subjected to different centrifugal forces under the centrifugal field formed inside the hydrocyclone. Among them, coarser and heavier sediment particles with a gravity greater than the centrifugal force will move downward along the inner wall of the hydrocyclone and will eventually be transported to the downstream sand discharge box for centralized collection or discharge; while lighter and finer particles overflow from the second outlet of the second hydrocyclone and can enter the subsequent processing unit or the recirculation system.

[0031] By installing the second hydrocyclone, not only is the grading efficiency of the sand discharge system improved, but the load on the sand discharge box is also effectively reduced, thereby improving the stability and operating efficiency of the entire sediment treatment system.

[0032] Based on the above embodiments, in one embodiment of this specification, the system further includes an inclined conveying screw, which is located downstream of the sand discharge box, and the end of the conveying screw closer to the sand discharge box is lower than the other end.

[0033] Specifically, the screw is installed at an angle of 15°–20°, with its lower end connected to the sand discharge box. Driven by a motor, the screw rotates slowly, pushing the wet sand from the discharge box upwards. During this process, moisture between the sand particles is continuously drained out under the pressure of gravity and the screw, flowing back into the system or into the municipal sewer network.

[0034] The inclined arrangement combined with screw conveyor has the dual functions of conveying and preliminary dewatering, which significantly reduces the moisture content of the recovered fine sand, making it easier for subsequent use and improving resource utilization.

[0035] Based on the above embodiments, in one embodiment of this specification, the system further includes a scum pressing device, located downstream of the scum filtering device. During operation, the scum filtering device periodically opens the scum discharge valve to flush trapped organic impurities such as leaves and branches into the scum pressing device (typically a screw extruder). This device applies progressive pressure to the scum material through a variable-pitch screw shaft, squeezing out moisture to form a dry scum cake with a moisture content of approximately 60%, which is then discharged into the scum collection box.

[0036] The implementation of the embodiments in this specification can effectively reduce the volume of organic slag and lower subsequent disposal costs; the dehydrated slag is easier to utilize as biomass fuel or compost raw material for resource recovery; at the same time, it avoids the accumulation of wet slag in the system, causing blockage or decay, and ensures the long-term stable operation of the system.

[0037] Based on the above embodiments, in one embodiment of this specification, the bottom of the first compartment and the bottom of the second compartment are "V" shaped.

[0038] Specifically, the bottoms of the first and second compartments converge at the center from the inclined plates on both sides to form a V-shaped trough. A first and second sand-discharging screw are respectively arranged along the length of the V-shaped trough. This ensures that fine sand settling at any location can slide into the bottom of the V-shaped trough under gravity and be promptly pushed out by the screws. The implementation of this embodiment eliminates the dead zones in sludge removal found in traditional flat-bottom sedimentation tanks, preventing effective volume loss or poor sludge removal caused by long-term fine sand accumulation. Simultaneously, the V-shaped structure and the screws work together to achieve continuous sand removal, significantly improving sludge removal efficiency and system reliability.

[0039] Based on the above embodiments, in one embodiment of this specification, the screening particle size range of the second hydrocyclone is ≥50 µm. In actual operating parameter settings, by adjusting the feed pressure (typically 0.2–0.4 MPa), underflow diameter, and hydrocyclone cone angle, the second hydrocyclone can stably separate inorganic particles with a particle size of 0.05 mm (i.e., 50 µm) or larger.

[0040] The implementation of the embodiments in this specification can effectively recover fine sand resources, significantly improve economic benefits, and at the same time reduce the suspended solids load entering the municipal pipe network, thereby reducing the pressure on downstream sewage treatment.

[0041] Based on the above embodiments, in one embodiment of this specification, an inclined separation plate is provided in the second compartment.

[0042] Specifically, multiple sets of separation plates can be densely installed in the second compartment at a 60° angle, with the high end near the outlet and the low end near the inlet. After the mud enters from the overflow port of the first hydrocyclone, it slowly rises in the gap between the inclined plates, and the fine sand particles slide down the plate surface to the bottom of the V-shape under the action of gravity.

[0043] By setting up inclined plates, the effective settling area can be greatly increased and the particle settling distance can be shortened, enabling efficient collection of fine sand (<100 µm). Combined with a V-shaped bottom and a sand discharge screw, the system's ability to treat low-concentration fine sand can be significantly improved, ensuring clean effluent.

[0044] Based on the above embodiments, in one embodiment of this specification, both the first and second hydrocyclones are conical hydrocyclones, and the separation particle size of the second hydrocyclone is smaller than that of the first hydrocyclone. In a specific configuration, the first hydrocyclone has a larger separation particle size (e.g., Φ300 mm) and a higher flow rate, mainly used for rapid separation of high-concentration coarse sand; the second hydrocyclone has a smaller separation particle size (e.g., Φ150 mm) and a lower flow rate, but achieves stronger centrifugal force through higher feed pressure or a steeper cone angle.

[0045] As can be seen, the two-stage hydrocyclone provided in this application can achieve high-flow coarse separation and high-precision fine screening, respectively, ensuring recovery accuracy and avoiding the problem that a single hydrocyclone cannot balance high flow rate and high precision.

[0046] It should also be understood that, in the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "or" relationship.

[0047] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0048] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0049] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0050] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0051] This application uses specific embodiments to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A pre-sedimentation tank sedimentation sludge and sand treatment system, characterized in that, include: The booster pump is connected at one end to the sedimentation tank of the waterworks and at the other end to the inlet of the scum filter device, and is used to transfer the sediment in the sedimentation tank to the scum filter device. The other end of the scum filtration device is connected to the first hydrocyclone, which is used to filter objects larger than a preset first size in the sediment and to transfer the filtered sediment to the first hydrocyclone. The first hydrocyclone has a first outlet connected to a first compartment of the slurry tank and a second outlet connected to a second compartment of the slurry tank. It is used to transport sediments with a gravity greater than centrifugal force to the first compartment through the first outlet and to transport sediments with a gravity less than or equal to centrifugal force to the second compartment through the second outlet. The mortar tank includes: a first compartment and a second compartment, wherein a first sand-discharging screw is provided at the bottom of the first compartment and a second sand-discharging screw is provided at the bottom of the second compartment, and both the first and second sand-discharging screws are used to transport the bottom sediment to the downstream sand-discharging box; The second compartment has a water outlet on its side, which is higher than the second sand discharge screw. The water outlet is used to transport water to the downstream municipal pipeline.

2. The pre-sedimentation tank sedimentation sludge treatment system according to claim 1, characterized in that, A sawtooth weir is provided in the mortar pool. The sawtooth weir is connected to the outlet and is located upstream of the outlet.

3. The pre-sedimentation tank sedimentation sludge treatment system according to claim 1, characterized in that, A second hydrocyclone is provided upstream of the sand discharge box, which is connected to the output end of the first sand discharge screw and the output end of the second sand discharge screw. The second hydrocyclone is used to separate the sediments transported by the first sand discharge screw and the second sand discharge screw. The second hydrocyclone transports sediments with gravity greater than centrifugal force to the sand discharge box.

4. The pre-sedimentation tank sedimentation sludge treatment system according to claim 3, characterized in that, The system further includes: an inclined conveying screw, which is downstream of the sand discharge box, and one end of the conveying screw near the sand discharge box is lower than the other end.

5. The pre-sedimentation tank sedimentation sludge treatment system according to claim 1, characterized in that, Also includes: A scum pressing device is located downstream of the scum filtration device and is used to press and dehydrate the filtered material filtered by the scum filtration device.

6. The pre-sedimentation tank sedimentation sludge treatment system according to claim 1, characterized in that, The bottoms of both the first and second cavities are V-shaped.

7. The pre-sedimentation tank sedimentation sludge treatment system according to claim 3, characterized in that, The particle size range for screening by the second hydrocyclone is ≥50µm.

8. The pre-sedimentation tank sedimentation sludge treatment system according to claim 1, characterized in that, An inclined separation plate is provided inside the second compartment, with one end of the separation plate near the water outlet being higher than the other end.

9. The pre-sedimentation tank sedimentation sludge treatment system according to claim 3, characterized in that, Both the first hydrocyclone and the second hydrocyclone are conical hydrocyclones, and the separation particle size of the second hydrocyclone is smaller than that of the first hydrocyclone.

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