Sandstone wastewater treatment device and method
By combining an influent buffer tank, thickener, coagulation integrated equipment and desludge dewatering room into a system, and using a PLC controller for real-time monitoring and automatic adjustment, the problems of low efficiency and error-proneness in sand and gravel wastewater treatment have been solved, achieving efficient and reliable water quality control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- POWERCHINA ZHONGNAN ENG
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-10
AI Technical Summary
Existing sand and gravel wastewater treatment processes are inefficient and prone to errors, especially the sludge at the bottom of the thickener is easily clogged, making it difficult to meet water quality design requirements.
The treatment system consists of an inlet buffer tank, a thickener, an integrated coagulation unit, a clear water tank, and a desludge dewatering room. Combined with real-time monitoring and automatic allocation by a PLC controller, the parallel design of the booster pump and the sludge conveying pump achieves precise control and redundancy guarantee of material transmission.
It improves the efficiency of sand and gravel wastewater treatment, avoids human error, reduces operating costs, and ensures that the effluent quality meets design requirements and is less prone to clogging.
Smart Images
Figure CN122355432A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wastewater treatment technology for pumped storage power stations, specifically to a sand and gravel wastewater treatment device and method. Background Technology
[0002] In the treatment of wastewater from the sand and gravel industry, the concentration of suspended solids in the wastewater is relatively high, typically ranging from tens of thousands to hundreds of thousands of milligrams per liter. Due to its high specific gravity, the wastewater is often separated into a clear liquid and a high concentration of precipitates by the gravity of the suspended particles themselves. Common water treatment processes include "mechanical pretreatment - auxiliary sedimentation - reuse or discharge to meet standards," "chemical mixer - pre-sedimentation unit - water purifier - reuse or discharge to meet standards," "sand and gravel separator - DH high-efficiency wastewater purifier - reuse or discharge to meet standards," and "A / O buried integrated wastewater treatment unit." For sand and gravel wastewater with extremely high inorganic suspended solids content and good settling properties, the "mechanical pretreatment - thickener - coagulation integrated equipment - clear water tank" process is conventionally used, as it requires less land and achieves better treatment results.
[0003] However, the current "mechanical pretreatment - thickener - reuse or discharge in compliance" process has the following problems in reality: the influent contains a lot of suspended solids, the influent and effluent and sludge discharge are mainly based on manual experience, the effluent is very likely to exceed the design requirements, and the work efficiency is low. The large amount of sludge at the bottom of the thickener can easily block the bottom sludge discharge pipe, making it difficult to meet the water quality design requirements. Summary of the Invention
[0004] The present invention aims to solve the problems of low efficiency and error-proneness in the treatment of sand and gravel wastewater in the prior art, and provides a sand and gravel wastewater treatment device and method.
[0005] To achieve the above objectives, a first aspect of the present invention provides a sand and gravel wastewater treatment device, comprising:
[0006] The inlet buffer tank is equipped with an inlet flow meter at its input end to detect the inlet flow rate of sand and gravel wastewater. The inlet buffer tank is also equipped with an inlet suspended solids detector and an inlet level gauge to detect the concentration and level of suspended solids in the inlet buffer tank. A thickener, the input end of which is connected to the output end of the influent buffer tank, and a sludge meter is installed inside the thickener; The integrated coagulation equipment includes an inlet mixing zone, an inclined plate sedimentation zone, and a coagulation outlet pipe connected in sequence, wherein the inlet mixing zone is connected to the outlet end of the thickener. The clear water tank is equipped with an effluent suspended solids detector and an effluent level gauge to detect and discharge compliant or reusable clear water from the coagulation effluent pipe. The desliming room is equipped with a diaphragm plate and frame filter press and a dosing device. The diaphragm plate and frame filter press is connected to the sludge conveying pipeline, and the dosing device is used to add chemicals into the sludge conveying pipeline. The PLC controller is used to acquire data from the influent flow meter, influent suspended solids detector, influent level gauge, sludge meter, effluent suspended solids detector and effluent level gauge, and to control the material transfer between the influent buffer tank, thickener, coagulation integrated equipment and desludge dewatering room.
[0007] In one embodiment, the input end of the thickener is located at the top of the thickener, and a lift pump is provided between the output end of the inlet buffer tank and the input end of the thickener to lift the sand and gravel wastewater in the inlet buffer tank to the input end at the top of the thickener. The booster pump is also connected in parallel with a standby booster pump. Both the booster pump and the standby booster pump are communicatively connected to a PLC controller. The PLC controller controls the material transfer between the inlet buffer tank and the thickener by controlling the operating conditions of the booster pump and the standby booster pump.
[0008] In one embodiment, the lower cavity inside the thickener is an inverted cone shape, and the tip of the cone is connected to the desliming chamber via a sludge conveying pipe; The sludge conveying pipeline is equipped with a sludge conveying pump, and a backup sludge conveying pump is connected in parallel. Both the sludge conveying pump and the backup sludge conveying pump are connected to a PLC controller. The PLC controller controls the material transfer between the thickener and the desludge dewatering room by controlling the operating conditions of the sludge conveying pump and the backup sludge conveying pump.
[0009] In one embodiment, a guide tube is provided inside the thickener. One end of the guide tube serves as the input end of the thickener and is connected to the inlet buffer tank, while the other end extends to the bottom of the thickener. The bottom end of the guide tube is configured as a funnel-shaped opening.
[0010] In one embodiment, the inlet buffer tank and the clear water tank are both constructed of brick and concrete or are made of carbon steel with corrosion protection, and the thickener and the integrated concrete coagulation equipment are both made of carbon steel with corrosion protection.
[0011] In one embodiment, the integrated coagulation equipment is positioned above the clear water tank, so that the effluent from the integrated coagulation equipment flows naturally into the clear water tank under the action of gravity.
[0012] In one embodiment, both the inlet water level gauge and the outlet water level gauge are ultrasonic level gauges; The sludge meter is an ultrasonic sludge meter, and it is installed at the top inside the thickener.
[0013] In one embodiment, the PLC controller is installed in a prefabricated house.
[0014] A second aspect of the present invention provides a method for treating sand and gravel wastewater, using the sand and gravel wastewater treatment device described above, comprising the following steps: The inlet water level sensor detects the current water level in the inlet water buffer tank in real time and transmits the water level data to the PLC controller. The PLC controller compares the current liquid level with the preset dead water level, low water level, high water level and alarm water level in the inlet buffer tank; When the water level in the inlet buffer tank is rising and the inlet level gauge detects a dead water level, the lift pump is shut down via the PLC controller. When the sand and gravel wastewater is being fed into the system, if the inlet level gauge detects a low water level, the PLC controller will control the booster pump to switch from the off state to the start state; if the inlet level gauge detects a high water level, the PLC controller will display a warning status; if the inlet level gauge detects an alarm water level, the PLC controller will activate the standby booster pump. When the water level in the inlet buffer tank is dropping and the inlet level gauge detects that the water level has dropped from the alarm level to the high level, the standby booster pump is shut down via the PLC controller; when the inlet level gauge detects that the high level has dropped to the dead level, the booster pump is shut down via the PLC controller.
[0015] In one embodiment, the sludge meter detects the current sludge level in the thickener cavity in real time and transmits the sludge level data to the PLC controller. The PLC controller compares the current sludge level with the preset sludge level, low sludge discharge level, high sludge discharge level, and sludge discharge alarm level in the thickener cavity. When the sludge level inside the thickener is rising and the sludge meter detects no sludge, the sludge discharge pump is shut down via the PLC controller. When the thickener is in the water-filling state and the sludge meter detects a low sludge discharge level, the sludge discharge pump is switched from off to on via the PLC controller. When the sludge meter detects a high sludge discharge level, a warning status is displayed via the PLC controller. When the sludge meter detects a sludge discharge alarm level, the standby sludge discharge pump is activated via the PLC controller. When the sludge level inside the thickener is decreasing and the sludge meter detects that the sludge level has dropped from the sludge discharge alarm position to the sludge discharge high position, the standby sludge conveying pump is shut down; when the sludge meter detects that the sludge level has dropped from the sludge discharge high position to the no sludge position, the sludge conveying pump is shut down via the PLC controller. During the operation of the booster pump, sludge pump, and thickener, the following relationship is satisfied by the PLC controller: [a×b×c / (ρ×s)]-vt / s=(0.8~1.2)h; Where a is the flow rate of the booster pump, b is the booster pump time, c is the suspended solids concentration, v is the flow rate of the sludge conveying pump, t is the sludge conveying time of the sludge conveying pump, h is the sludge level in the thickener, ρ is the sludge density in the thickener, and s is the cross-sectional area of the thickener.
[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a sand and gravel wastewater treatment device, comprising: an inlet buffer tank, the inlet of which is equipped with an inlet flow meter for detecting the inlet flow rate of sand and gravel wastewater; an inlet suspended solids detector and an inlet level gauge for detecting the suspended solids concentration and level in the inlet buffer tank; a thickener, the inlet of which is connected to the output of the inlet buffer tank, and a sludge meter is installed inside the thickener; an integrated coagulation device, comprising an inlet mixing zone, an inclined plate sedimentation zone, and a coagulation outlet pipe connected in sequence, the inlet mixing zone being connected to the outlet at the top of the thickener; and a clear water tank, which contains a... The system includes an effluent suspended solids detector and an effluent level gauge for detecting and discharging compliant or reusable clean water from the coagulation effluent pipe; a sludge dewatering room equipped with a diaphragm plate and frame filter press and a dosing device, wherein the diaphragm plate and frame filter press is connected to the sludge conveying pipeline, and the dosing device is used to add chemicals into the sludge conveying pipeline; and a PLC controller for acquiring data from the influent flow meter, influent suspended solids detector, influent level gauge, sludge meter, effluent suspended solids detector, and effluent level gauge, and for controlling material transfer between the influent buffer tank, thickener, integrated coagulation equipment, and sludge dewatering room. The above settings enable real-time monitoring of various parameters of the sand and gravel wastewater treatment device. The PLC controller then processes the acquired monitoring data to achieve unified automatic allocation of the influent buffer tank, thickener, coagulation integrated equipment, clear water tank, and desludge dewatering room. This maximizes the effectiveness of each component, eliminating the need for manual monitoring and control, greatly improving the efficiency of sand and gravel wastewater treatment, avoiding human error, simplifying and facilitating effluent control, reducing clogging, lowering operating costs, and ensuring that the treated water quality meets design requirements. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a plan view of a sand and gravel wastewater treatment device according to an embodiment of the present invention.
[0019] 1. Inlet buffer tank; 1-1. Inlet flow meter; 1-2. Inlet suspended solids detector; 1-3. Inlet level gauge; 1-4. Booster pump; 1-5. Standby booster pump; 2. Thickener; 2-1. Sludge meter; 2-2. Sludge conveying pipeline; 2-3. Sludge conveying slurry pump; 2-4. Standby sludge conveying slurry pump; 3. Integrated coagulation equipment; 3-1. Inlet mixing zone; 3-2. Inclined plate sedimentation zone; 3-3. Coagulation outlet pipe; 4. Clear water tank; 4-1. Outlet suspended solids detector; 4-2. Outlet level gauge; 5. Desludge dewatering room; 5-1. Diaphragm plate and frame filter press; 5-2. Dosing device; 6. PLC control room; 6-1. PLC controller. Detailed Implementation
[0020] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.
[0021] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.
[0022] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0023] Please see Figure 1 One embodiment of a sand and gravel wastewater treatment device includes: The inlet buffer tank 1 is equipped with an inlet flow meter 1-1 at its input end for detecting the inlet flow of sand and gravel wastewater. The inlet buffer tank 1 is also equipped with an inlet suspended solids detector 1-2 and an inlet level gauge 1-3 for detecting suspended solids and liquid level in the inlet buffer tank 1. Thickener 2, whose input end is connected to the output end of influent buffer tank 1, and sludge meter 2-1 is installed inside thickener 2; The coagulation integrated equipment 3 includes an inlet mixing zone 3-1, an inclined plate sedimentation zone 3-2, and a coagulation outlet pipe 3-3 connected in sequence. The inlet mixing zone 3-1 is connected to the outlet end of the thickener 2. Clear water tank 4, which is equipped with an effluent suspended solids detector 4-1 and an effluent level gauge 4-2, for detecting and discharging compliant or reusable clear water from the coagulation effluent pipe 3-3; The desliming room 5 is equipped with a diaphragm plate and frame filter press 5-1 and a dosing device 5-2. The diaphragm plate and frame filter press 5-1 is connected to the sludge conveying pipeline 2-2, and the dosing device 5-2 is used to add chemicals into the sludge conveying pipeline 2-2. The PLC controller 6-1 is used to acquire data from the inlet flow meter 1-1, the inlet suspended solids detector 1-2, the inlet level gauge 1-3, the sludge meter 2-1, the effluent suspended solids detector 4-1, and the effluent level gauge 4-2, and then transmit the data to the sand and gravel wastewater lift pump 1-4 and the sludge conveying pump 2-3 via data lines. It also controls the material transfer between the inlet buffer tank 1, the thickener 2, the coagulation integrated equipment 3, and the desludge dewatering room 5.
[0024] This embodiment achieves real-time monitoring of various parameters of the sand and gravel wastewater treatment system through the above settings. Then, the PLC controller 6-1 processes the acquired monitoring data to achieve unified allocation of the influent buffer tank 1, thickener 2, coagulation integrated equipment 3, clear water tank 4, and desludge dewatering room 5, so that each part can maximize its effectiveness without the need for manual monitoring and control. This greatly improves the efficiency of sand and gravel wastewater treatment, avoids human error, makes effluent control simpler and more convenient, is less prone to clogging, and the treated water quality meets the design requirements.
[0025] In one embodiment, the input end of the thickener 2 is located at the top of the thickener 2, and a lift pump 1-4 is provided between the output end of the inlet buffer tank 1 and the input end of the thickener 2 for lifting the sand and gravel wastewater in the inlet buffer tank 1 to the input end at the top of the thickener 2; the lift pump 1-4 is also connected in parallel with a standby lift pump 1-5, and both the lift pump 1-4 and the standby lift pump 1-5 are communicatively connected to the PLC controller 6-1. The PLC controller 6-1 controls the material transfer between the inlet buffer tank 1 and the thickener 2 by controlling the operating conditions of the lift pump 1-4 and the standby lift pump 1-5.
[0026] By setting up booster pumps 1-4 and standby booster pumps 1-5, and controlling them through a controller, the material conveying between the output end of the influent buffer tank 1 and the input end of the thickener 2 can be precisely controlled. The parallel design of the two pumps ensures design redundancy, and they can be turned on together when necessary to maximize the sewage treatment efficiency.
[0027] In one embodiment, the lower cavity inside the thickener 2 is an inverted cone shape, and the tip of the cone is connected to the desludge chamber 5 through the sludge conveying pipe 2-2; the cone shape facilitates sludge sedimentation, separation and discharge.
[0028] The mud conveying pipeline 2-2 is equipped with a mud conveying slurry pump 2-3, and the mud conveying slurry pump 2-3 is also connected in parallel with a standby mud conveying slurry pump 2-4. Both the mud conveying slurry pump 2-3 and the standby mud conveying slurry pump 2-4 are communicatively connected to the PLC controller 6-1. The PLC controller 6-1 controls the material transfer between the thickener 2 and the desliming room 5 by controlling the operating conditions of the mud conveying slurry pump 2-3 and the standby mud conveying slurry pump 2-4.
[0029] By setting up sludge conveying pump 2-3 and standby sludge conveying pump 2-4, and controlling them through a controller, the material conveying between thickener 2 and desludge dewatering room 5 can be accurately and controllably achieved. The parallel design of the two pumps ensures design redundancy, and at the same time, they can be turned on together when necessary to maximize sludge discharge efficiency.
[0030] In one embodiment, a guide tube is provided inside the thickener 2. One end of the guide tube serves as the input end of the thickener 2 and is connected to the inlet buffer tank 1. The other end extends to the bottom of the thickener 2. The bottom end of the guide tube is configured as a funnel-shaped opening.
[0031] In one embodiment, both the inlet buffer tank 1 and the clear water tank 4 are constructed of brick and mortar or are made of corrosion-resistant carbon steel, while both the thickener 2 and the integrated coagulation unit 3 are made of corrosion-resistant carbon steel. The corrosion-resistant carbon steel design ensures that the equipment is not easily damaged and has a longer service life.
[0032] In one embodiment, the integrated coagulation device 3 is positioned above the clear water tank 4, so that the effluent from the integrated coagulation device 3 flows naturally into the clear water tank 4 under the action of gravity.
[0033] In one embodiment, both the inlet level gauge 1-3 and the outlet level gauge 4-2 are ultrasonic level gauges; The sludge meter 2-1 is an ultrasonic sludge meter 2-1, and it is installed at the top inside the thickener 2.
[0034] In one embodiment, the PLC controller 6-1 is installed in a prefabricated house.
[0035] A second aspect of the present invention provides a method for treating sand and gravel wastewater, using the sand and gravel wastewater treatment device described above, comprising the following steps: The inlet water level sensor detects the current water level in the inlet water buffer tank 1 in real time and transmits the water level data to the PLC controller 6-1. The PLC controller 6-1 compares the current liquid level with the preset dead water level, low water level, high water level and alarm water level in the inlet buffer tank 1; When the water level in the inlet buffer tank 1 is rising and the inlet level gauge 1-3 detects a dead water level, the lift pump 1-4 is shut down by the PLC controller 6-1. When the sand and gravel wastewater is being fed into the system, if the inlet level gauge 1-3 detects a low water level, the PLC controller 6-1 will control the booster pump 1-4 to change from the off state to the start state; if the inlet level gauge 1-3 detects a high water level, the PLC controller 6-1 will display a warning status; if the inlet level gauge 1-3 detects an alarm water level, the PLC controller 6-1 will activate the standby booster pump 1-5. When the water level in the inlet buffer tank 1 is dropping, and the inlet level gauge 1-3 detects that the water level has dropped from the alarm level to the high level, the standby booster pump 1-5 is shut down through the PLC controller 6-1; when the inlet level gauge 1-3 detects that the high water level has dropped to the dead water level, the booster pump 1-4 is shut down through the PLC controller 6-1.
[0036] In one embodiment, the sludge meter 2-1 detects the current sludge level inside the thickener 2 in real time and transmits the sludge level data to the PLC controller 6-1. The PLC controller 6-1 compares the current sludge level with the preset sludge level, low sludge discharge level, high sludge discharge level, and sludge discharge alarm level inside the thickener 2. When the sludge level in thickener 2 is rising and sludge meter 2-1 detects no sludge, the sludge discharge action of sludge conveying pump 2-3 is shut down via PLC controller 6-1; when thickener 2 is in the water-filling state, and sludge meter 2-1 detects a low sludge discharge level, the sludge conveying pump 2-3 is switched from the off state to the on state via PLC controller 6-1; when sludge meter 2-1 detects a high sludge discharge level, a warning status is displayed via PLC controller 6-1; when sludge meter 2-1 detects a sludge discharge alarm level, the standby sludge conveying pump 2-4 is turned on via PLC controller 6-1. When the sludge level in the thickener 2 is decreasing and the sludge meter 2-1 detects that the sludge level has dropped from the sludge discharge alarm position to the sludge discharge high position, the standby sludge conveying pump 2-4 is shut down; when the sludge meter 2-1 detects that the sludge level has dropped from the sludge discharge high position to the no sludge position, the sludge conveying pump 2-3 is shut down through the PLC controller 6-1. During the operation of booster pumps 1-4, slurry pumps 2-3, and thickener 2, the following relationship is satisfied by PLC controller 6-1: [a×b×c / (ρ×s)]-vt / s=(0.8~1.2)h; Where a is the flow rate of lift pump 1-4, b is the lifting time of lift pump 1-4, c is the data of inlet suspended solids detector 1-2, v is the flow rate of sludge conveying pump 2-3, t is the sludge conveying time of sludge conveying pump 2-3, h is the sludge level in thickener 2, ρ is the sludge density in thickener 2, and s is the cross-sectional area of thickener 2.
[0037] This embodiment describes the treatment of sand and gravel wastewater using a specific wastewater treatment device and method. The device receives a continuous, balanced intake of water for 10 hours during the day. The dimensions of the influent buffer tank 1 are 7m × 6.5m × 4m (length × width × height). The influent flow meter 1-1 detects flow rates between 180m³ / h and 200m³ / h, and the influent suspended solids detector 1-2 detects flow rates between 31250 and 32000 mg / L. The height of the influent buffer tank 1 is set as follows: 0.15m as the dead water level, 0.5m as the low water level, and 3m as the... The high water level is 0.2m, and the alarm water level is 3.5m. The flow rate of lift pumps 1-4 and standby lift pumps 1-5 is 200m³ / h. The thickener 2 has a diameter × height of φ6m × 11m. The height of thickener 2 is set as 0m for no sludge, 0.5m for low sludge discharge, 4.5m for high sludge discharge, and 5m for sludge discharge alarm. The flow rate of sludge conveying pumps 2-3 and standby sludge conveying pumps 2-4 is 120m³ / h. The sludge density in thickener 2 is 1300mg / cm³. The sand and gravel wastewater treatment system is in normal operation. When the ultrasonic level gauge 1-3 in the inlet buffer tank 1 is between the high and low water levels, and the sludge level gauge 2-1 on thickener 2 is between the low and high sludge discharge levels, the sludge conveying pump 2-3 starts the sludge discharge action when it is at the low sludge discharge level. The PLC controller 6-1 in the PLC control room 6 operates automatically according to the program.
[0038] The above are merely preferred embodiments of the present invention. It should be noted that the present invention is not limited to the above embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should also be considered within the scope of protection of the present invention.
Claims
1. A sand and gravel wastewater treatment device, characterized in that, include: The inlet buffer tank is equipped with an inlet flow meter at its input end to detect the inlet flow rate of sand and gravel wastewater. The inlet buffer tank is also equipped with an inlet suspended solids detector and an inlet level gauge to detect the concentration and level of suspended solids in the inlet buffer tank. A thickener, the input end of which is connected to the output end of the influent buffer tank, and a sludge meter is installed inside the thickener; The integrated coagulation equipment includes an inlet mixing zone, an inclined plate sedimentation zone, and a coagulation outlet pipe connected in sequence, wherein the inlet mixing zone is connected to the outlet end of the thickener. The clear water tank is equipped with an effluent suspended solids detector and an effluent level gauge to detect and discharge compliant or reusable clear water from the coagulation effluent pipe. The desliming room is equipped with a diaphragm plate and frame filter press and a dosing device. The diaphragm plate and frame filter press is connected to the sludge conveying pipeline, and the dosing device is used to add chemicals into the sludge conveying pipeline. The PLC controller is used to acquire data from the influent flow meter, influent suspended solids detector, influent level gauge, sludge meter, effluent suspended solids detector and effluent level gauge, and to control the material transfer between the influent buffer tank, thickener, coagulation integrated equipment and desludge dewatering room.
2. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The input end of the thickener is located at the top of the thickener, and a lift pump is provided between the output end of the inlet buffer tank and the input end of the thickener to lift the sand and gravel wastewater in the inlet buffer tank to the input end at the top of the thickener. The booster pump is also connected in parallel with a standby booster pump. Both the booster pump and the standby booster pump are communicatively connected to a PLC controller. The PLC controller controls the material transfer between the inlet buffer tank and the thickener by controlling the operating conditions of the booster pump and the standby booster pump.
3. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The lower cavity inside the thickener is an inverted cone shape, and the tip of the cone is connected to the desliming room through a mud conveying pipe. The sludge conveying pipeline is equipped with a sludge conveying pump, and a backup sludge conveying pump is connected in parallel. Both the sludge conveying pump and the backup sludge conveying pump are connected to a PLC controller. The PLC controller controls the material transfer between the thickener and the desludge dewatering room by controlling the operating conditions of the sludge conveying pump and the backup sludge conveying pump.
4. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The thickener is equipped with a guide tube inside. One end of the guide tube serves as the input end of the thickener and is connected to the inlet buffer tank. The other end extends to the bottom of the thickener. The bottom end of the guide tube is configured as a funnel-shaped opening.
5. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The inlet buffer tank and clear water tank are both constructed of brick and concrete or are made of carbon steel with corrosion protection. The thickener and the integrated concrete coagulation equipment are both made of carbon steel with corrosion protection.
6. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The integrated coagulation equipment is positioned above the clear water tank, allowing the effluent from the integrated coagulation equipment to flow naturally into the clear water tank under gravity.
7. The sand and gravel wastewater treatment device according to claim 1, characterized in that, Both the inlet and outlet water level gauges are ultrasonic level gauges; The sludge meter is an ultrasonic sludge meter, and it is installed at the top inside the thickener.
8. The sand and gravel wastewater treatment device according to claim 1, characterized in that, The PLC controller is installed in a prefabricated house.
9. A method for treating sand and gravel wastewater, using the sand and gravel wastewater treatment device according to any one of claims 1-8, characterized in that, Includes the following steps: The inlet water level sensor detects the current water level in the inlet water buffer tank in real time and transmits the water level data to the PLC controller. The PLC controller compares the current liquid level with the preset dead water level, low water level, high water level and alarm water level in the inlet buffer tank; When the water level in the inlet buffer tank is rising and the inlet level gauge detects a dead water level, the lift pump is shut down via the PLC controller. When the sand and gravel wastewater is being fed into the system, if the inlet level gauge detects a low water level, the PLC controller will control the booster pump to switch from the off state to the start state; if the inlet level gauge detects a high water level, the PLC controller will display a warning status; if the inlet level gauge detects an alarm water level, the PLC controller will activate the standby booster pump. When the water level in the inlet buffer tank is dropping and the inlet level gauge detects that the water level has dropped from the alarm level to the high level, the standby booster pump is shut down via the PLC controller; when the inlet level gauge detects that the high level has dropped to the dead level, the booster pump is shut down via the PLC controller.
10. The method for treating sand and gravel wastewater according to claim 9, characterized in that, Also includes: The sludge meter detects the current sludge level in the thickener cavity in real time and transmits the sludge level data to the PLC controller. The PLC controller compares the current sludge level with the preset sludge level, low sludge discharge level, high sludge discharge level, and sludge discharge alarm level in the thickener cavity. When the sludge level inside the thickener is rising and the sludge meter detects no sludge level, the sludge discharge action of the sludge conveying pump is turned off by the PLC controller; when the thickener is in the water-filling state and the sludge meter detects a low sludge discharge level, the sludge conveying pump is controlled by the PLC controller to change from the original off state to the on state. When the sludge meter detects a high sludge level, the PLC controller displays an early warning status. When the sludge meter detects the sludge discharge alarm position, the backup sludge conveying pump is activated via the PLC controller; When the sludge level inside the thickener is decreasing and the sludge meter detects that the sludge level has dropped from the sludge discharge alarm position to the sludge discharge high position, the standby sludge conveying pump is shut down; when the sludge meter detects that the sludge level has dropped from the sludge discharge high position to the no sludge position, the sludge conveying pump is shut down via the PLC controller. During the operation of the booster pump, sludge pump, and thickener, the following relationship is satisfied by the PLC controller: [a×b×c / (ρ×s)]-vt / s=(0.8~1.2)h; Where a is the flow rate of the booster pump, b is the booster pump time, c is the suspended solids concentration, v is the flow rate of the sludge conveying pump, t is the sludge conveying time of the sludge conveying pump, h is the sludge level in the thickener, ρ is the sludge density in the thickener, and s is the cross-sectional area of the thickener.