An unpowered slurry treatment method for a concrete mixing wastewater settling tank

Abstract

This invention belongs to the field of wastewater treatment technology for concrete mixing systems, specifically relating to a non-powered sludge treatment method for sedimentation tanks used in concrete mixing wastewater treatment. This method relies on a non-powered mode to complete sludge collection, transportation, drying, and supernatant return, eliminating the need for external power equipment and effectively solving the drawbacks of traditional sedimentation tanks, such as manual cleaning, operational interruptions, high energy consumption, and unstable effluent quality. This method involves setting up independent sludge collection pits at the bottom of each sedimentation tank and laying unconnected sludge discharge pipelines. The gravity head is created by the difference in liquid level between the tank and the discharge port, achieving non-powered gravity-flow transportation of sludge. The supernatant from drying flows back to the inlet well for secondary treatment, saving water resources. This invention enables long-term, non-powered sludge treatment and efficient, graded drying, with low operating costs, convenient maintenance, safety, and water conservation. It is suitable for sludge treatment applications in sedimentation tanks used in concrete mixing wastewater treatment in water conservancy and hydropower projects.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology for concrete mixing systems, and specifically relates to a non-powered sludge treatment method for sedimentation tanks used in concrete mixing wastewater treatment. Background Technology

[0002] During the construction of water conservancy and hydropower projects, concrete mixing systems generate a large amount of wastewater with high suspended solids. This wastewater is characterized by high suspended solids concentration (typically 2000 mg / L to 50000 mg / L), high pH (10 to 12), large fluctuations in water volume, intermittent discharge, and slow settling. Currently, with increasingly stringent environmental protection requirements, three-stage sedimentation tanks are commonly used in engineering projects to treat wastewater through step-by-step sedimentation, ensuring the water quality meets standards for reuse. However, the concentrated sludge in the sedimentation tanks is difficult to remove. During operation, sludge accumulation often necessitates periodic or manual cleaning, which is not only labor-intensive and involves sludge with high moisture content, but also makes it difficult to consistently meet effluent standards due to the influence of sludge. Furthermore, the sludge removal process is prone to environmental pollution due to leaks and spills.

[0003] Traditional sedimentation tank methods for treating sludge and water have the following technical drawbacks:

[0004] 1) Sludge treatment relies on manual labor or power equipment: Traditional sedimentation tanks require manual sludge removal, which poses significant safety risks such as suffocation and sinking; some use mechanical sludge removal or air-lift sludge removal, which rely on electric power, have complex structures, high failure rates, are not suitable for field construction sites without stable power supply, and are prone to damage and have high maintenance costs.

[0005] 2) Impact on construction continuity: When cleaning manually or repairing power equipment, the wastewater in the sedimentation tank needs to be drained, which leads to the shutdown of the mud and water treatment system. This makes it impossible to treat the wastewater generated during construction, which poses a risk of environmental violations and also affects the progress of concrete mixing and construction.

[0006] 3) Low sludge treatment efficiency: The bottom of sedimentation tanks is mostly flat or slightly sloping, which makes sludge prone to caking, difficult to clean, time-consuming, and the discharged sludge has a high water content, long drying cycle, large land area, and is prone to secondary pollution.

[0007] 4) Unstable effluent quality: Long-term accumulation of sludge occupies the effective volume of the sedimentation tank, aggravates water flow disturbance, and leads to excessive concentration of suspended solids in the effluent; in addition, a large amount of supernatant is discharged along with the sludge during the sludge discharge process, which not only wastes water resources, but also further affects the stability of effluent.

[0008] These technical deficiencies have seriously affected the treatment effect of concrete mixing wastewater sedimentation tanks and the continuity of concrete mixing production. The industry urgently needs a mud and water treatment method that requires no external power, no manual cleaning, can be operated continuously, and is easy to operate to solve the above-mentioned technical pain points. Summary of the Invention

[0009] The purpose of this invention is to provide a non-powered sludge treatment method for sedimentation tanks used in concrete mixing wastewater treatment, which solves the problems of traditional concrete mixing wastewater sedimentation tank sludge treatment requiring manual cleaning, reliance on power equipment, operation interruption, low efficiency, and unstable effluent. It achieves the technical effects of non-powered drive, no manual cleaning, efficient graded treatment, and supernatant reuse, reducing operating costs and safety risks, and ensuring the continuity of engineering construction.

[0010] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0011] This invention provides a non-powered sludge treatment method for concrete mixing wastewater sedimentation tanks, based on a concrete mixing wastewater sedimentation tank system. The system includes multiple sedimentation tanks connected in sequence, independent sludge discharge pipes corresponding to each stage, a sludge drying tank, and a supernatant return pipeline. The method includes the following steps:

[0012] 1) Sludge collection pit layout: Sludge collection pits are set up at the bottom of each sedimentation tank, and gravity is used to allow the sludge generated by the sedimentation of wastewater to naturally collect and concentrate at the bottom of the pit;

[0013] 2) Non-powered sludge discharge: An independent sludge discharge pipe is connected to the bottom of each sludge collection pit. The sludge discharge pipe is connected to the corresponding sludge drying tank. When discharging sludge, the gravity head is formed by the height difference between the liquid level in the tank and the outlet of the sludge discharge pipe, which pushes the concentrated sludge in the sludge collection pit to the sludge drying tank by gravity.

[0014] 3) Sludge drying and supernatant return: The sludge is dried in the sludge drying tank. The supernatant precipitated during the drying process flows back to the front end of the multi-stage sedimentation tank by gravity. It is mixed with the new wastewater and then re-enters the sedimentation system for treatment.

[0015] 4) Sludge drying tank allocation: When multiple sludge drying tanks are set up, the sludge drying tanks can be connected and disconnected. When the capacity of a certain sludge drying tank is insufficient or sludge needs to be centrally treated, sludge can be exchanged between the drying tanks.

[0016] Furthermore, the multi-stage sedimentation tank includes an inlet tank, a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank connected in sequence, and the sludge drying tank consists of three independently set tanks, with each sludge discharge pipe connected to a different sludge drying tank to achieve graded sludge discharge.

[0017] Furthermore, in step 1), the mud collection pit is a sunken inverted truncated pyramid shape, with the bottom of the pit located at the lowest point of the corresponding pool body, and the slope angle of the pit wall is not less than 55°.

[0018] Furthermore, in step 2), the sludge discharge pipe is a PE pipe, with its inlet end located at the lowest point of the sludge collection pit, and the sludge discharge pipes are not connected to each other.

[0019] Furthermore, in step 2), a double-flange manual gate valve is installed near the outer wall of the pool for each sludge discharge pipe, and the corresponding gate valve is manually opened when discharging sludge.

[0020] Furthermore, in step 2), the height difference between the liquid level in the pool and the outlet of the sludge discharge pipe is not less than 2m.

[0021] Furthermore, in step 3), the sludge drying tank is provided with a slope structure on the vehicle inlet side, and each drying tank is provided with a supernatant return port, with the bottom of the return pipe located on top of the dried sludge layer.

[0022] Furthermore, the dried sludge is mechanically transported away from the drying tank by a loader entering from the sloping side.

[0023] Furthermore, in step 4), each sludge drying tank is connected and disconnected through connecting pipes and control valves.

[0024] Compared with existing technologies, this invention adopts an integrated innovative design of "independent sludge collection + parallel sludge discharge + gravity drive + closed-loop reflux", which has the following advantages:

[0025] 1. Parallel independent sludge discharge without power: Sludge is discharged by gravity head formed by the liquid level difference, without the need for pumps or other external power, which is energy-saving and environmentally friendly; the sludge discharge pipes of each sedimentation tank are not connected to each other and discharge independently, avoiding mutual interference and making the system operation more stable.

[0026] 2. No manual cleaning required: Sludge is automatically discharged, eliminating the need for personnel to enter and clean it, greatly reducing labor intensity.

[0027] 3. Graded drying and closed-loop recirculation: The drying tanks are graded according to their functions to improve the sludge drying efficiency; the supernatant recirculation system is equipped to realize the recycling and reprocessing of wastewater, reduce water waste, and improve the stability of effluent quality.

[0028] 4. Flexible linkage and continuous operation guarantee: The drying tank can be flexibly connected and disconnected through connecting pipes and control valves, and the tank volume can be dynamically adjusted to adapt to the characteristics of large fluctuations in sludge discharge water volume and intermittent discharge; and the supernatant can be discharged according to the actual operation, shortening the drying time; in addition, the cleaning cycle is greatly extended, ensuring continuous production and improving work efficiency.

[0029] 5. Low operating cost and easy maintenance: The sludge removal system has no powered equipment or components, requires no equipment maintenance, and has an extremely low failure rate; the drying tank has a side slope, facilitating the entry and exit of a loader to clean the dried sludge, significantly improving efficiency and simplifying maintenance, resulting in high reliability. This method is particularly suitable for the complex environment of construction sites, especially for wastewater treatment in concrete mixing systems of water conservancy and hydropower projects.

[0030] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the following description of the embodiments will be briefly introduced. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

[0032] Figure 1 This is a schematic diagram of the planar layout according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic cross-sectional view of the sedimentation tank and sludge collection pit in an embodiment of the present invention;

[0034] Figure 3 This is a cross-sectional structural diagram of the mud discharge pipe and gate valve in an embodiment of the present invention. Detailed Implementation

[0035] 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.

[0036] like Figure 1 As shown, this embodiment provides a non-powered sludge treatment method for sedimentation tanks used in concrete mixing wastewater, based on the following system: an inlet tank, a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank connected in sequence. Each tank has an independent inverted truncated quadrangular sludge collection pit at the bottom, and each sludge collection pit is connected to a DN200PE independent sludge discharge pipe at the bottom. The four sludge discharge pipes are respectively connected to three independent sludge drying tanks (inlet tank, tertiary sedimentation tank → No. 3 drying tank; primary sedimentation tank → No. 1 drying tank; secondary sedimentation tank → No. 2 drying tank). Each sludge discharge pipe is equipped with a double-flange manual gate valve, and each drying tank is equipped with a supernatant return pipeline to the inlet well. Connecting pipes and control valves are provided between the drying tanks.

[0037] The specific process is as follows:

[0038] Sludge collection: The slope angle of the sludge collection pit is designed to be 59°~78°. The concrete mixing wastewater enters the inlet pool from the inlet well and undergoes sedimentation in the primary, secondary and tertiary sedimentation tanks. Under the action of gravity, the sludge naturally settles into the sludge collection pit at the bottom of each tank, completing the natural concentration.

[0039] Non-powered sludge discharge: The height difference between the liquid level in the design tank and the outlet of the sludge discharge pipe is 2.0m to 2.2m. During the normal sedimentation stage, the double-flange manual gate valve remains closed. During sludge discharge, the gate valves on the sludge discharge pipes of each tank are opened sequentially according to the design cycle. Taking the first-stage sedimentation tank as an example, after the gate valve is opened, the 2.14m liquid level difference generates hydrostatic pressure, which drives the high-concentration sludge in the sludge collection pit to flow by gravity through the PE sludge discharge pipe into the No. 1 drying tank. Sludge discharge of a single tank can be completed in about 1 to 2 minutes. No power equipment is involved in the entire process, making it simple to operate and highly efficient.

[0040] Sludge drying: After entering the corresponding drying tank, the sludge dries naturally. The supernatant precipitated during the drying process flows back to the inlet well by gravity through the return port set in the drying tank. After mixing with the newly entered wastewater, it enters the sedimentation system for secondary treatment, realizing the recycling of water resources.

[0041] Sludge cleaning and tank capacity adjustment: The dried sludge is periodically transported out of the drying tank by a loader from the sloping side, achieving mechanized cleaning without the need for personnel to enter the tank. When the sludge discharge is large enough to fill a certain drying tank, the connecting valve can be opened to discharge the sewage into other empty drying tanks, flexibly adjusting the tank capacity to ensure continuous treatment.

[0042] This embodiment completely solves many pain points of traditional sedimentation tank sludge treatment through the above-mentioned non-powered sludge treatment method, realizing sludge treatment without manual cleaning, non-powered operation, continuous treatment, low operating cost, simple maintenance, stable effluent quality, and is fully adaptable to the construction conditions of water conservancy and hydropower projects. At the same time, it can be extended to the treatment of sludge in sedimentation tanks for concrete mixing wastewater in the fields of building construction, mining, and tunnels.

[0043] By setting up independent sludge collection pits at the bottom of each sedimentation tank and laying out unconnected sludge discharge pipelines, the gravity head is formed by the height difference between the liquid level in the tank and the sludge discharge port, realizing the gravity-flow transport of sludge without power. The supernatant precipitated during the drying process flows back to the inlet well by gravity and is treated together with the raw water for secondary treatment, avoiding the waste of water resources. Ultimately, it completely realizes the long-term manual cleaning-free, power-free treatment and efficient staged drying of sludge. It has the characteristics of low operating cost, simple maintenance, safety and reliability, water saving and environmental protection, and greatly reducing the labor intensity of workers. It is especially suitable for the sludge treatment of concrete mixing wastewater sedimentation tanks in water conservancy and hydropower projects.

[0044] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A non-powered sludge treatment method for concrete mixing wastewater sedimentation tanks, based on a concrete mixing wastewater sedimentation tank system, the system comprising sequentially connected multi-stage sedimentation tanks, independent sludge discharge pipes corresponding to each stage, sludge drying tanks, and supernatant return pipelines, characterized in that, The method includes the following steps: 1) Sludge collection pit layout: Sludge collection pits are set up at the bottom of each sedimentation tank, and gravity is used to allow the sludge generated by the sedimentation of wastewater to naturally collect and concentrate at the bottom of the pit; 2) Non-powered sludge discharge: An independent sludge discharge pipe is connected to the bottom of each sludge collection pit. The sludge discharge pipe is connected to the corresponding sludge drying tank. When discharging sludge, the gravity head is formed by the height difference between the liquid level in the tank and the outlet of the sludge discharge pipe, which pushes the concentrated sludge in the sludge collection pit to the sludge drying tank by gravity. 3) Sludge drying and supernatant return: The sludge is dried in the sludge drying tank. The supernatant precipitated during the drying process flows back to the front end of the multi-stage sedimentation tank by gravity. It is mixed with the new wastewater and then re-enters the sedimentation system for treatment. 4) Sludge drying tank allocation: When multiple sludge drying tanks are set up, the sludge drying tanks can be connected and disconnected. When the capacity of a certain sludge drying tank is insufficient or sludge needs to be centrally treated, sludge can be exchanged between the drying tanks.

2. The non-powered sludge treatment method according to claim 1, characterized in that, The multi-stage sedimentation tank includes an inlet tank, a primary sedimentation tank, a secondary sedimentation tank, and a tertiary sedimentation tank connected in sequence. The sludge drying tank consists of three independently set tanks, and each sludge discharge pipe is connected to a different sludge drying tank to achieve graded sludge discharge.

3. The non-powered sludge treatment method according to claim 1, characterized in that, In step 1), the mud collection pit is a sunken inverted quadrangular truncated pyramid shape, with the bottom of the pit located at the lowest point of the corresponding pool body, and the slope angle of the pit wall is not less than 55°.

4. The non-powered sludge and water treatment method according to claim 1, characterized in that, In step 2), the sludge discharge pipe is a PE pipe, with its inlet end located at the lowest point of the sludge collection pit, and the sludge discharge pipes are not connected to each other.

5. The non-powered sludge treatment method according to claim 1, characterized in that, In step 2), a double-flange manual gate valve is installed near the outer wall of the pool on each sludge discharge pipe. The corresponding gate valve is manually opened when discharging sludge.

6. The non-powered sludge treatment method according to claim 1, characterized in that, In step 2), the height difference between the liquid level in the pool and the outlet of the sludge discharge pipe is not less than 2m.

7. The non-powered sludge treatment method according to claim 1, characterized in that, In step 3), the sludge drying tank is equipped with a slope structure on the vehicle inlet side, and each drying tank is equipped with a supernatant return port, with the bottom of the return pipe located on top of the dried sludge layer.

8. The non-powered sludge treatment method according to claim 7, characterized in that, The dried sludge is mechanically transported out by a loader from the sloping side of the drying tank.

9. The non-powered sludge treatment method according to claim 1, characterized in that, In step 4), each sludge drying tank is connected and disconnected through connecting pipes and control valves.

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