Low-energy-consumption sludge high-dryness dehydration low-temperature drying system and control method thereof

Abstract

The invention relates to a low-energy-consumption sludge high-dryness dehydration low-temperature drying system and a control method thereof. A hydraulic high-pressure feeding pump is used for conveying conditioned sludge from a sludge tank to an ultrahigh-pressure double-diaphragm low-temperature drying all-in-one machine; in the ultrahigh-pressure double-diaphragm low-temperature drying all-in-one machine, heat energy is provided for the ultrahigh-pressure double-diaphragm low-temperature drying all-in-one machine through an electromagnetic heating device; meanwhile, a vacuum pump is started, water vapor generated in the dehydration process is pumped out by the vacuum pump and cooled through a condenser, and heat is recycled; and the dehydrated dry sludge is conveyed to a dry material bin for storage through a screw conveyer. The energy consumption can be obviously reduced, and the sludge dewatering efficiency can be improved; meanwhile, through automatic control and an optimized operation mode, the stability and continuity of sludge treatment are improved, manual intervention is reduced, and the treatment effect and the operation safety are ensured.

Description

Technical Field

[0001] The invention relates to the field of sludge treatment, and in particular to a low-energy consumption sludge high-drying dehydration and low-temperature drying system and a control method thereof. Background Art

[0002] Existing sludge treatment methods mainly include natural drying, mechanical dehydration and thermal drying. The natural drying method removes water through evaporation and osmosis, which is low in cost, but occupies a large area, is limited by climatic conditions, and has a long drying cycle, which is prone to produce odor and environmental pollution. The mechanical dehydration method uses mechanical force to squeeze and dehydrate the sludge. Common ones include belt filter presses, plate and frame filter presses, etc. Although the dehydration efficiency is high, the energy consumption is large, the equipment is severely worn, and the operation and maintenance costs are high. Thermal drying technology achieves a high drying efficiency by heating the sludge to evaporate water, but the energy consumption is huge and the operating cost is high. However, these methods have some significant problems. First, the natural drying method is inefficient and cannot meet the efficiency and environmental requirements of modern sludge treatment; second, although the mechanical dehydration method has a high dehydration efficiency, the high energy consumption and high operating cost limit its scope of application; third, although the thermal drying technology has a high drying efficiency, the operating cost and energy consumption issues limit its practical application.

[0003] In order to solve these problems, existing means attempt to reduce energy consumption by improving the design and operating parameters of mechanical dewatering equipment, such as using high-pressure filtration and diaphragm pressing technology to improve dewatering efficiency and reduce energy consumption. However, this design does not completely solve the energy consumption and efficiency problems in the sludge treatment process, especially under low temperature conditions, the dewatering performance of the sludge will be affected, resulting in reduced dewatering efficiency and increased energy consumption. It can be seen that there is an urgent need for an improved method that can both reduce energy consumption and improve sludge dewatering efficiency. Summary of the invention

[0004] In order to solve the problems of high energy consumption and low efficiency of the above-mentioned existing sludge treatment methods and achieve the goals of high efficiency, energy saving and environmental protection of sludge treatment, the purpose of the present invention is to provide a low-energy consumption sludge high-drying dehydration and low-temperature drying system and its control method. By integrating advanced hydraulic high-pressure feed pumps, ultra-high pressure double diaphragm low-temperature drying all-in-one machines, and automatic control to optimize the operating mode, high-efficiency sludge dehydration can be achieved under low temperature conditions, while significantly reducing the energy consumption of the system.

[0005] To achieve the above object, the present invention provides the following technical solutions: A low-energy sludge high-drying dehydration and low-temperature drying system, comprising: a sludge tank, a sludge sonic conditioner, an automatic dosing device, a hydraulic high-pressure feed pump, an ultra-high-pressure double-diaphragm low-temperature drying all-in-one machine, a vacuum pump, a filter plate cleaning device, a condenser, an electromagnetic heating device, a heat exchanger, an insulation water tank, a screw conveyor, a dry material bin and an automatic control device; wherein the sludge tank is used to temporarily store the sludge pumped from the sludge pool; the sludge sonic conditioner is arranged in the sludge pool and is used to pre-treat the sludge and destroy the flocculation structure in the sludge by sound waves; the automatic dosing device automatically adds flocculants or other chemicals to the sludge pool through a dosing pipeline; the hydraulic high-pressure feed pump conveys the conditioned sludge from the sludge tank to the ultra-high-pressure double-diaphragm low-temperature drying all-in-one machine through a sludge inlet pipe; the ultra-high-pressure double-diaphragm low-temperature drying all-in-one machine integrates high-pressure filtration, high-pressure diaphragm squeezing, and low-temperature vacuum drying functions; the vacuum pump is an ultra-high-pressure double-diaphragm low-temperature drying all-in-one machine Create a negative pressure environment to reduce the boiling point of water in the filter cake and promote water evaporation; the condenser is used to cool the water vapor discharged from the vacuum pump and recover heat; the electromagnetic heating device provides heat energy for the ultra-high pressure double diaphragm low temperature drying machine to heat the sludge or maintain the temperature; the insulated water tank is connected to the ultra-high pressure double diaphragm low temperature drying machine through the pressing water inlet pipe and the pressing water return pipe; the heat exchanger is externally connected to the steam heat energy of the plant area and exchanges heat with the insulated water tank through the heat exchange circulation pipeline; the screw conveyor is located at the bottom of the ultra-high pressure double diaphragm low temperature drying machine and is used to transport the dehydrated dry sludge to the dry material bin; the dry material bin is used to store the dehydrated dry sludge; the filter plate cleaning device is integrated in the ultra-high pressure double diaphragm low temperature drying machine and is used to clean the filter plate after the filter plate completes the sludge dehydration and remove the sludge residue on the filter cloth; the automatic control device is used to obtain the data of the sensor and automatically control the operation of the low-energy sludge high-drying dehydration and low-temperature drying system.

[0006] Furthermore, the present invention provides a low-energy consumption sludge high-drying dehydration and low-temperature drying control method, comprising the following steps: S111. Sludge pretreatment: Use a sludge sonic conditioner to pretreat the sludge to destroy the flocculation structure in the sludge; add flocculants or other chemicals to the sludge through an automatic dosing device; S112, sludge transportation: use a hydraulic high-pressure feed pump to transport the conditioned sludge from the sludge tank to the ultra-high pressure double diaphragm low-temperature drying integrated machine; S113, sludge dehydration: In the ultra-high pressure double diaphragm low temperature drying machine, the sludge is further dehydrated; the electromagnetic heating device is used to provide heat energy to the ultra-high pressure double diaphragm low temperature drying machine; at the same time, the vacuum pump is started, and the water vapor generated during the dehydration process is pumped out by the vacuum pump and cooled by the condenser to recover heat; S114, dry sludge transportation and storage: the dehydrated dry sludge is transported to the dry material silo for storage through a screw conveyor; S115, filter plate cleaning: start the filter plate cleaning device to clean the filter plate and remove the sludge residue on the filter cloth.

[0007] The invention provides a low-energy consumption sludge high-drying dehydration and low-temperature drying system and a control method thereof, which has the advantages of: (1) The low-energy sludge high-drying dehydration and low-temperature drying system of the present invention adopts an electromagnetic heating device to provide heat energy for the ultra-high pressure double-diaphragm low-temperature drying integrated machine. At the same time, the use of a vacuum pump reduces the boiling point of water in the filter cake, promotes water evaporation, and enhances the dehydration effect. The setting of the condenser is used to cool the exhausted water vapor, recover heat, and further reduce energy consumption; while achieving efficient dehydration, energy consumption is greatly reduced.

[0008] (2) The sludge high-drying dehydration and low-temperature drying system of the present invention automatically adjusts the pressure and flow rate according to the working state of the filter press through the control method of the hydraulic high-pressure feed pump, reduces manual intervention, and improves the convenience and safety of operation. Through real-time data monitoring and preset logic, using pressure sensors, flow meters and saturation sensors to collect key parameters, the system automatically switches to the next working stage at the most appropriate time to ensure the efficiency and effect of sludge treatment. This intelligent control not only improves the treatment efficiency, but also reduces the risks caused by operational errors, making the entire sludge treatment process more stable and reliable.

[0009] (3) The present invention uses a CFD model method to optimize the operating parameters of the agitator. The CFD model simulates the mixing and settling process in the sludge tank, optimizes the operating time of the agitator and the settling time of the sludge, so as to improve the sludge treatment efficiency and reduce energy consumption. Not only is the operating time of the agitator accurately controlled to ensure that the sludge is fully mixed in the tank to prevent the formation of sediment, but also the static mode allows solid particles to settle to the bottom of the tank and separate the clear supernatant. This optimized operation mode greatly reduces energy consumption, extends the service life of the equipment, and improves the overall performance of the sludge treatment process.

[0010] (4) The present invention estimates the filtrate through an image analysis-based method, and then estimates and automatically controls the optimal value of the pressing time. A fixed camera is used to capture the image of the filtrate discharged from the filter press, and color features are extracted through image processing technology, and these features are used to predict the pressing time. The changes in the color of the filtrate are monitored in real time, and the operating parameters of the filter press are adjusted using the color analysis results to optimize the dehydration process. The color analysis and pressing time prediction are integrated into the automatic control device, which realizes the automatic adjustment of the sludge dehydration process, reduces the need for manual monitoring and intervention, improves the automation level of sludge treatment and the dehydration quality, and reduces energy consumption and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1It is a process flow chart of the low-energy consumption sludge high-drying dehydration and low-temperature drying system of the present invention; Figure 2 for Figure 1 A magnified view of the local area I; Figure 3 for Figure 1 A magnified view of the local area II; Figure 4 The control flow of the hydraulic high-pressure feed pump working process of the present invention is Figure 1 ; Figure 5 The control flow of the hydraulic high-pressure feed pump working process of the present invention is Figure 2 ; Figure 6 It is a front view of the filter plate cleaning device of the present invention; Figure 7 is a side view of the filter plate cleaning device of the present invention; Figure 8 is an overall diagram of the filter plate cleaning device of the present invention; Fig. 9 for Figure 8 A magnified view of the local area A; Fig.10 It is a flow chart of the low-energy consumption sludge high-drying dehydration and low-temperature drying control method of the present invention; Fig.11 A flow chart of a method for obtaining optimal operating parameters of an agitator based on a CFD model method according to the present invention; Fig.12 The present invention is a flow chart of the method for estimating the optimal pressing time based on image analysis of filtrate. DETAILED DESCRIPTION

[0012] In order to fully understand the present invention, detailed steps and detailed structures will be proposed in the following description to illustrate the technical solution of the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0013] Embodiment 1

[0014] like Figure 1-Figure 3As shown, the low-energy consumption sludge high-drying dehydration and low-temperature drying system of the present invention comprises: a sludge tank 20, a sludge sonic conditioner, an automatic dosing device 40, a hydraulic high-pressure feed pump 30, an ultra-high pressure double-diaphragm low-temperature drying integrated machine 100, a vacuum pump 50, a filter plate cleaning device 90, a condenser 60, an electromagnetic heating device, a heat exchanger 70, an insulation water tank 80, a screw conveyor, a dry material bin and an automatic control device; wherein the sludge tank 20 is used to temporarily store the sludge pumped from the sludge pool; the sludge sonic conditioner, It is arranged in the sludge tank and is used to pre-treat the sludge and destroy the flocculation structure in the sludge by sound waves; the automatic dosing device 40 automatically adds flocculants or other chemicals to the sludge tank through the dosing pipeline; the hydraulic high-pressure feed pump 30 transports the conditioned sludge from the sludge tank to the ultra-high pressure double diaphragm low-temperature drying all-in-one machine 100 through the sludge inlet pipe; the ultra-high pressure double diaphragm low-temperature drying all-in-one machine 100 integrates high-pressure filtration, high-pressure diaphragm pressing, and low-temperature vacuum drying functions; the vacuum pump 50 is an ultra-high pressure The double-diaphragm low-temperature drying machine creates a negative pressure environment, reduces the boiling point of water in the filter cake, and promotes water evaporation; the condenser 60 is used to cool the water vapor discharged from the vacuum pump and recover heat; the electromagnetic heating device provides heat energy for the ultra-high pressure double-diaphragm low-temperature drying machine for heating sludge or maintaining temperature; the insulated water tank 80 is connected to the ultra-high pressure double-diaphragm low-temperature drying machine 100 through the pressing water inlet pipe and the pressing water return pipe; the heat exchanger 70 is connected to the plant area steam heat energy through the heat exchange circulation pipeline and the insulated water tank 8 0 heat exchange; a screw conveyor, located at the bottom of the ultra-high pressure double diaphragm low temperature drying all-in-one machine 100, is used to transport the dehydrated dry sludge to the dry material bin; the dry material bin stores the dehydrated dry sludge; the filter plate cleaning device 90, integrated in the ultra-high pressure double diaphragm low temperature drying all-in-one machine 100, is used to clean the filter plate after the filter plate completes the sludge dehydration and remove the sludge residue on the filter cloth; the automatic control device is used to obtain the data of the sensor and automatically control the operation of the low-energy sludge high-drying dehydration and low-temperature drying system.

[0015] Correspondingly, such as Fig.10 As shown, the low-energy consumption sludge high-drying dehydration and low-temperature drying system of the present invention has the following main control steps during implementation: S111. Sludge pretreatment: Use a sludge sonic conditioner to pretreat the sludge to destroy the flocculation structure in the sludge. Add flocculants or other chemicals to the sludge through an automatic dosing device.

[0016] S112, sludge transportation: use hydraulic high-pressure feed pump to transport the conditioned sludge from the sludge tank to the ultra-high pressure double diaphragm low-temperature drying machine.

[0017] S113, sludge dehydration: In the ultra-high pressure double diaphragm low temperature drying all-in-one machine, the sludge is further dehydrated; the ultra-high pressure double diaphragm low temperature drying all-in-one machine is provided with heat energy by an electromagnetic heating device; at the same time, the vacuum pump is started, and the water vapor generated during the dehydration process is pumped out by the vacuum pump and cooled by the condenser to recover heat.

[0018] S114. Dry sludge transportation and storage: The dehydrated dry sludge is transported to the dry material silo for storage through a screw conveyor.

[0019] S115, filter plate cleaning: start the filter plate cleaning device to clean the filter plate and remove the sludge residue on the filter cloth.

[0020] Specifically, in step S113, after the sludge enters the machine, it first undergoes a high-pressure filtration stage, and uses an ultra-high-pressure double-diaphragm filter plate for double-sided extrusion tympanic membrane filtration. The diaphragm filter plate is made of a high-pressure tempered rubber diaphragm filter plate, the diaphragm is made of highly elastic nitrile rubber, and the tympanic membrane has a large expansion coefficient. After high-pressure filtration, the sludge is further deeply squeezed and dehydrated by the ultra-high-pressure double diaphragm. The inner lining of the filter plate is a high-strength spring steel plate, and the frame is made of high-pressure resistant tempered rubber material. No reinforcement points or a small number of reinforcement points are required to achieve a high expansion compression coefficient. Hot water is introduced to heat the sludge in the filter chamber, and the vacuum pump is started at the same time. When the vacuum pump is working, the filter chamber is in a negative pressure state, and the water boiling point of the filter cake is reduced under the negative pressure state. The heat source is continuously circulated and input, and the vacuum pump continuously removes water vapor until the moisture content of the filter cake is dried to less than 30%.

[0021] Embodiment 2 Based on the above embodiment 1, as a further preferred example, Figure 6-Figure 9 As shown, the filter plate cleaning device of the present invention comprises: a driving mechanism 1, wherein the driving mechanism 1 drives the pulley 10 to rotate, and the driving mechanism 1 drives the pulley 10 to rotate through the bevel gear, and the two pulleys 10 are connected by belt transmission. After the driving motor 11 is started, the power is transmitted to the pulley 10 through the bevel gear. The transmission characteristics of the bevel gear enable the power to be stably transmitted while changing the direction, thereby ensuring the accuracy and reliability of the transmission. The two pulleys 10 are connected by belt transmission, which can effectively buffer the impact when the motor starts and stops, making the power transmission more stable and reducing the mechanical damage to other parts of the equipment. The belt transmission also has a certain overload protection capability. When the cleaning machine encounters an unexpected increase in resistance during operation, the belt slips to prevent the motor and other transmission parts from being damaged due to overload. The belt transmission brings the filter plate to be cleaned and the flushing mechanism 5 of the cleaning machine close to each other. When the filter plate to be cleaned is located directly below the flushing mechanism, the level sensor 9 transmits the signal to the controller, and the level sensor 9 is a photoelectric sensor.

[0022] The support mechanism 2 supports and stabilizes the overall structure of the cleaning machine; the guide wheel 4 is rotatably mounted on the support mechanism 2 to assist the guidance of the lifting mechanism 3 when it moves; the lifting mechanism 3 includes a fixed frame and a slider 13, the slider 13 is arranged at the connection between the lifting mechanism 3 and the support mechanism 2, and the water inlet pipe 8 is fixedly installed inside the fixed frame; the lifting mechanism 3 is driven by the lifting motor 6, and the lifting mechanism 3 drives the flushing mechanism 5 to move vertically; the lifting motor 6 drives the lifting mechanism 3 to move through the wire rope; the lifting sensor 7 is fixedly installed on one side of the support mechanism 2. The support mechanism 2 provides a solid and reliable basic support for the entire cleaning machine, and the guide wheel 4 installed on the support mechanism 2 plays a precise guiding role when the lifting mechanism 3 moves in the vertical direction. A slider 13 is arranged at the connection between the lifting mechanism 3 and the support mechanism 2. The slider 13 can not only reduce the friction resistance between the lifting mechanism 3 and the support mechanism 2, making the lifting movement smoother, but also play a certain role in limiting and stabilizing the movement of the lifting mechanism 3, ensuring that the lifting mechanism 3 will not deviate or jam during the up and down movement. The lifting sensor 7 detects the position information of the lifting mechanism 3 and feeds the data back to the controller. The controller accurately controls the operation of the lifting motor 6 according to the received signal, thereby accurately adjusting the height position of the flushing mechanism 5.

[0023] The flushing mechanism 5 includes a water inlet pipe 8, a water pipe 15 and a nozzle 17. The water inlet pipe 8 is a water source input channel of the flushing mechanism 5. It is connected to an external water source through a movable hose, such as a high-pressure water system provided by a high-pressure water pump; the nozzle 17 is connected to the water inlet pipe 8 through the water pipe 15; and the level sensor 9 is fixedly installed on the upper side of the driving mechanism 1. A baffle 14 is arranged on the outside of the flushing mechanism 5. The side of the support mechanism 2 away from the driving mechanism 1 is rotatably installed with two casters. The lifting sensor 7 and the level sensor 9 are connected to the controller. The driving motor 11 and the lifting motor 6 are connected to the controller. A stabilizing wheel 12 is also arranged at the bottom of one side of the support mechanism 2. When the flushing mechanism 5 is working, the water inlet pipe 8 is first connected to the external water source, and the water source is stably transmitted to the nozzle 17 through the water pipe 15, and the nozzle 17 sprays out a high-pressure water flow. Among them, the water inlet pipe 8 is fixedly installed inside the fixed frame of the lifting mechanism 3, which ensures the stability of the water inlet pipe 8 during the lifting process and prevents the water supply from being affected or causing equipment failure due to the shaking of the water pipe. The high-pressure water flow sprayed by the nozzle 17 has sufficient impact force, which can effectively remove dirt, residues and other attachments on the surface of the filter plate. The baffle 14 arranged outside the flushing mechanism 5 plays a good protective role.

[0024] During the cleaning process, the driving motor 11 transmits power to the pulley 10 through the bevel gear. The two pulleys 10 are connected by belt drive, so that the filter plate to be cleaned and the flushing mechanism of the cleaning machine are close to each other. When the filter plate to be cleaned is located directly below the flushing mechanism, the horizontal sensor 9 transmits a signal to the controller. The controller controls the operation of the lifting motor 6 according to the information fed back by the horizontal sensor 9. The lifting motor 6 drives the lifting mechanism 3 to move by using a wire rope. The lifting sensor 7 detects the position information of the lifting mechanism 3 and feeds the data back to the controller. The controller accurately controls the operation of the lifting motor 6 according to the received signal and accurately adjusts the height position of the flushing mechanism 5. When the flushing mechanism 5 reaches the flushing position, the water source is stably transmitted to the nozzle 17 through the water pipe 15. The nozzle 17 sprays high-pressure water to flush the filter plate, thereby realizing the automatic control of the entire cleaning machine. Through this automatic control method, not only the tediousness and errors of manual operation are reduced, but also the working efficiency and stability of the cleaning machine are improved, so that the cleaning operation can be completed more efficiently and accurately.

[0025] The filter plate cleaning device for the filter press of the present invention realizes efficient and automatic cleaning of the filter plate of the filter press through the coordinated work of multiple components such as the driving mechanism 1, the supporting mechanism 2, the lifting mechanism 3, the flushing mechanism 5, etc., combined with control elements such as the level sensor 9, the lifting sensor 7 and the controller, so that the cleaning machine has the advantages of good cleaning effect, high working efficiency, convenient operation, strong stability, etc.

[0026] Embodiment 3 On the basis of the above-mentioned embodiment 1, as a further preferred example, the hydraulic high-pressure feed pump in the present invention includes: a pump body, a plunger assembly, a valve, a hydraulic system, a seal, and a pressure regulating valve. The plunger assembly is made of alumina ceramics, which has high hardness and low surface roughness and is suitable for transporting materials containing solid particles; the pump body is used to accommodate the plunger; the valve includes an inlet valve and a discharge valve, which are used to control the inlet and outlet of the fluid to ensure the normal operation of the pump; the hydraulic system is used to provide pressure to make the plunger reciprocate in the pump cylinder; the driving device is a motor or other power source to provide power for the pump; the pressure regulating valve is used to adjust the working pressure to adapt to different working conditions; the seal prevents the fluid inside the pump from leaking.

[0027] The hydraulic high-pressure feed pump is equipped with a filter press to achieve efficient and energy-saving control. The specific method is that the hydraulic high-pressure feed pump works in a low-pressure and high-flow mode in the early stage, and automatically switches to medium pressure and medium speed according to the saturation of the filter press in the middle stage. After the filter press is saturated, it automatically enters high-pressure, low-speed and rapid squeezing for efficient energy saving.

[0028] In the early stage of filtration, the sludge has not yet formed a stable filter cake. At this time, the sludge needs to be quickly transported to the filter chamber to reduce the residence time of the sludge in the pipeline and prevent sludge sedimentation and blockage; low pressure and high flow rate quickly fill the filter chamber to reduce system pressure and energy consumption, while avoiding damage to the filter cloth or deformation of the filter plate due to excessive pressure. As the filter cake is formed, the space of the filter chamber is gradually filled. At this time, the flow rate needs to be appropriately reduced to ensure that the sludge is evenly distributed and a uniform filter cake is formed. Medium pressure and medium speed ensure the uniformity and integrity of the filter cake, avoid local overload or uneven pressure, and maintain high filtration efficiency. When the filter chamber is close to saturation, the moisture content in the filter cake needs to be further reduced to increase the dryness of the sludge. Increasing the pressure forces more water to be discharged through the filter cloth, improving the dehydration effect of the sludge. Under high pressure, the fluidity of the sludge is reduced, so the pump speed can be reduced to reduce energy consumption. Rapid pressing under high pressure can achieve a high sludge dryness in a short time and improve treatment efficiency.

[0029] The hydraulic high-pressure feed pump automatically adjusts the pressure and flow rate according to the working status of the filter press, reducing manual intervention and improving the convenience and safety of operation. By adopting different pressure and flow settings at different stages, energy consumption can be minimized while ensuring the treatment effect; at the same time, it can adapt to different sludge properties and treatment requirements, with good flexibility and adaptability.

[0030] In order to ensure that the filter press can switch between different stages efficiently and energy-savingly when processing sludge, the present invention also provides a control method for a hydraulic high-pressure feed pump, which uses a pressure sensor, a flow meter and a saturation sensor to collect key parameters based on real-time data monitoring and preset logic. Among them, the pressure sensor monitors the pressure in the filter chamber; the flow meter monitors the flow of the feed sludge; the saturation sensor: the automatic control device integrates all sensor data and controls the operation of the filter press according to the preset logic. Specifically, if Figure 4 As shown in the figure, the comprehensive judgment conditions for entering the medium-pressure and medium-speed stage from the low-pressure and high-speed stage are: Condition 1: The filling degree of the filter chamber reaches the first filling threshold (such as the filling degree of the filter chamber reaches 65%). The filling degree of the filter chamber refers to the volume or space ratio occupied by the sludge in the filter chamber. This parameter is crucial to the operation of the filter press because it is directly related to the efficiency of sludge treatment and the quality of the filter cake. The filling degree is indirectly judged by monitoring the pressure changes in the filter chamber. As the sludge fills, the pressure in the filter chamber will gradually increase. When the filter chamber is filled to a certain extent, it is necessary to reduce the feed amount or stop the feed to avoid overfilling that affects the formation of the filter cake and the discharge of the filtrate. The appropriate filling degree helps to form a uniform and dense filter cake, which is crucial to improving filtration efficiency and reducing the solid content in the filtrate.

[0031] Condition 2: The pressure changes to the first pressure threshold. During the filtration process, as the sludge is continuously filled and squeezed, the pressure in the filter chamber will gradually increase. This pressure change is monitored by installing a pressure sensor in the filter chamber. The initial value varies depending on the initial working state of the filter press and the nature of the sludge. When the pressure rises from this initial value to the first pressure threshold (i.e. 0.7 MPa), it indicates that the sludge has begun to form a filter cake and the sludge density in the filter chamber is increasing. At this time, it is necessary to reduce the feed amount and increase the pressure to switch to the medium pressure and medium speed stage.

[0032] Condition three: The filtration speed is below the first flow threshold. The filtration speed refers to the rate at which the sludge passes through the filter cloth, that is, the speed at which the filtrate is discharged through the filter cloth during the process of the sludge being pressed into the filter chamber and forming a filter cake. This speed can be monitored by a flow meter, which is installed on the filtrate discharge pipe to measure the amount of filtrate discharged per unit time. When the concentration or properties of the sludge change, causing the filtration speed to drop below the first flow threshold (i.e., 60%) of the maximum flow rate, the sludge becomes more difficult to filter due to reasons such as increased sludge concentration or larger particles. In this case, in order to maintain the filtration efficiency and ensure the quality of the filter cake, it is necessary to switch to the medium pressure and medium speed stage to adapt to the changes in the sludge properties. Preferably, the first flow threshold, i.e., the filtration speed, drops below 60% of the maximum flow rate.

[0033] The implementation method of the comprehensive judgment scheme for entering the medium-pressure and medium-speed stage from the low-pressure and high-speed stage is: monitor the above three conditions at the same time. When conditions one and two are met at the same time, start monitoring condition three. If condition three is also met within the first time threshold (5 minutes) after conditions one and two are met, it is considered to switch to the medium-pressure and medium-speed stage. If condition three is not met within the first time threshold (5 minutes), continue monitoring until all three conditions are met at the same time.

[0034] Condition 1, that is, the filling degree of the filter chamber reaches 65%, which means that the filter chamber has been initially filled with sludge and the sludge begins to form a filter cake of a certain thickness. Condition 2, that is, the pressure change rises from the initial value to 0.7 MPa, indicating that the sludge has begun to be squeezed and the sludge density in the filter chamber is increasing. When these two conditions are met at the same time, it means that the filling and squeezing of the sludge in the filter chamber have reached a certain degree, which is the critical point at which the sludge properties begin to change. At this time, condition 3, the sludge filtration speed becomes a key factor affecting the filter press efficiency. Condition 3, that is, the sludge filtration speed drops to less than 60% of the maximum flow rate, indicating that the sludge filtration resistance increases, which is due to the increase in sludge concentration or the enlargement of particles. After conditions 1 and 2 are met, if the filtration speed of condition 3 also decreases, it usually means that the properties of the sludge have changed, making the sludge more difficult to filter. At this time, in order to maintain the filtration efficiency and ensure the quality of the filter cake, it is necessary to adjust the working state of the filter press, that is, switch to the medium pressure and medium speed stage.

[0035] In addition, the time window of the first time threshold (such as 5 minutes) is set for flexible adjustment. During this time, if condition three is met, it means that the change in sludge properties is immediate, and the working state of the filter press needs to be adjusted as soon as possible to adapt to this change. If condition three is not met within the first time threshold (such as 5 minutes), it means that the sludge properties have not changed significantly, or the change is not enough to affect the filtration efficiency, so continue monitoring until all conditions are met at the same time. Continue monitoring until all conditions are met at the same time: ensure that the adjustment of the operating state of the filter press is based on the most comprehensive judgment. If condition three is not met within the first time threshold (such as 5 minutes), continued monitoring can avoid premature or unnecessary stage switching and ensure that the efficiency of the filter press is maximized in the current stage.

[0036] Further, such as Figure 5 As shown in the figure, the comprehensive judgment conditions for the comprehensive judgment scheme of entering the high-pressure and low-speed stage from the medium-pressure and medium-speed stage are: Condition 4: The filling degree of the filter chamber reaches the second filling threshold (such as the filling degree of the filter chamber reaches 85%). The filling degree of the filter chamber refers to the filling degree of the sludge in the filter chamber. When the filling degree of the filter chamber reaches the second filling threshold, it means that most of the space in the filter chamber is occupied by sludge and the filter cake has formed to a certain thickness. This condition indicates that the filling of the sludge is almost complete and the further formation of the filter cake will be limited by space. At this stage, in order to further dehydrate, the pressure needs to be increased, so consider switching to the high pressure and low speed stage.

[0037] Condition 5: The pressure rise rate reaches the second pressure threshold. The pressure rise rate refers to the rate of increase of the pressure in the filter chamber per unit time. When the pressure rise rate exceeds the second pressure threshold, it indicates that the compression resistance of the sludge in the filter chamber is increasing, and a greater pressure is needed to continue to push the filtrate through the filter cake. This condition indicates that the filter cake has reached a certain density, and further dehydration requires a higher pressure, so consider switching to a high pressure and low speed stage. Preferably, the second pressure threshold is a pressure rise rate exceeding 0.15 MPa per minute.

[0038] Condition six: The filtration rate drops to the second flow threshold. The filtration rate refers to the amount of liquid passing through the filter cloth per unit time. When the filtration rate drops below the second flow threshold of the maximum flow, it indicates that the resistance of the filter cake increases and the difficulty of the filtrate passing through the filter cake increases. This decline is caused by the filter cake becoming more dense or the water content in the filter cake decreasing. In this case, in order to maintain the filtration efficiency, the pressure needs to be increased, so consider switching to the high pressure and low speed stage. Preferably, the second flow threshold is when the filtration rate drops to less than 40% of the maximum flow.

[0039] Condition 7: The filter cake thickness reaches the first thickness threshold (such as 30mm) or the density reaches the first density threshold (such as 1.2g / cm³). The filter cake thickness refers to the physical thickness of the filter cake formed after the sludge is squeezed in the filter chamber during the filter pressing process; it is monitored by sensors installed on both sides of the filter plate. The filter cake density refers to the mass per unit volume of the filter cake, that is, the compactness of the filter cake. The higher the density, the denser the filter cake and the less water it contains. The density is calculated by measuring the weight and volume of the filter cake.

[0040] Condition 8: The clarity of the filtrate reaches the first transmittance threshold (such as the transmittance of the filtrate reaches more than 90%). Filtrate transmittance: refers to the ability of the filtrate to allow light to pass through. The higher the transmittance, the fewer solid particles in the filtrate and the clearer the filtrate. This is usually measured by an optical sensor installed in the filtrate discharge pipe, reflecting the quality of the filtration effect.

[0041] The implementation method of the comprehensive judgment scheme for entering the high-pressure and low-speed stage from the medium-pressure and medium-speed stage is as follows: monitor the above five conditions simultaneously. When conditions 4, 5 and 6 are met at the same time, start monitoring conditions 7 and 8. If conditions 7 and 8 are also met within 10 minutes after conditions 4, 5 and 6 are met, it is considered that the switch to the high-pressure and low-speed stage can be made. If conditions 7 and 8 are not met within 10 minutes, continue monitoring until all five conditions are met at the same time.

[0042] The implementation method is based on the requirements for filter cake quality and filtrate purity when the filter press transitions from the medium-pressure and medium-speed stage to the high-pressure and low-speed stage. Among them, conditions four, five, and six are synchronous: condition four, that is, the filling degree of the filter chamber reaches 85%, which means that the filter chamber space is almost completely occupied by sludge and the formation of the filter cake is nearly complete. Condition five, that is, the pressure rise rate exceeds the threshold, indicating that the pressing resistance of the filter cake is increasing, and a greater pressure is required to continue dehydration. Condition six, that is, the filtration rate drops below the threshold of the maximum flow rate, indicating that the resistance of the filter cake increases and further filtration becomes difficult. When these three conditions are met at the same time, it means that the filter cake has reached a certain thickness and density, the space in the filter chamber is almost filled, and the dehydration resistance of the filter cake is increasing. At this time, the thickness or density of the filter cake (condition seven) and the clarity of the filtrate (condition eight) become the key factors in determining whether to switch to the high-pressure and low-speed stage. Condition seven, that is, the thickness of the filter cake reaches the predetermined thickness or the density reaches the predetermined density, indicating that the filter cake is dense enough and the further dehydration effect will be limited. Condition 8 (clarity of filtrate): When the transmittance of the filtrate reaches a predetermined value or above, it indicates that there are very few solid particles in the filtrate and the dehydration effect of the filter cake is good. After conditions 4, 5, and 6 are met, if conditions 7 and 8 are also met, it indicates that the quality of the filter cake has reached the requirements and the purity of the filtrate is high enough. At this time, switch to the high pressure and low speed stage to further optimize the dehydration effect.

[0043] In addition, the time window of the second time threshold is set for flexible adjustment. During this time, if conditions seven and eight are met, it means that the state of the filter cake and filtrate has stabilized and the stage switching can be performed. If conditions seven and eight are not met within the second time threshold, it means that the state of the filter cake and filtrate has not yet reached the best state, and it is necessary to continue monitoring until all conditions are met at the same time to ensure that the stage switching is performed at the most appropriate time.

[0044] The present invention provides a control method for a hydraulic high-pressure feed pump. Based on real-time data monitoring and preset logic, a pressure sensor, a flow meter and a saturation sensor are used to collect key parameters. Through comprehensive judgment and implementation measures, the filter press can automatically switch to the next stage at the most appropriate time to ensure the efficiency and effect of sludge treatment, while reducing manual intervention and improving the safety and convenience of operation. By integrating multiple conditions, the instability caused by abnormal triggering of switching by a single condition is reduced; at the same time, a certain time window is given, allowing time to meet other conditions after the initial conditions are met, which increases flexibility. Finally, through comprehensive judgment, it is ensured that the operation stage of the filter press is switched at the most appropriate time to improve the overall processing efficiency.

[0045] Embodiment 4 The sludge tank of the present invention is provided with at least two agitators, which are equipped with at least three blades and installed on the vertical wall of the sludge tank. The agitator in the prior art runs continuously to maintain the uniformity of the sludge when it is pumped to the filter press, which results in higher energy consumption. The present invention controls the operation of the agitator by introducing a mixing mode and a static mode. By running the agitator (mixing mode) for a specific time period and then allowing the sludge to settle naturally in the static mode, the running time of the agitator is significantly reduced, thereby greatly reducing energy consumption. Uniform sludge mixing can reduce the energy consumption of the filter press when processing uneven sludge, and controlling the residence time of the sludge in the sludge tank can ensure that the sludge is transported to the filter press in the best condition, avoiding excessive sedimentation or too low sludge concentration, thereby improving the working efficiency of the filter press and reducing energy consumption. Fig.11 As shown, in order to obtain the optimal operating parameters of the agitator, the present invention adopts CFD model optimization method, and the optimization steps are as follows: S211. Data collection: Conduct static sedimentation experiments to obtain sedimentation velocity data at different sludge concentrations; conduct dynamic sedimentation experiments under controlled stirring speed to observe the effect of stirring on sedimentation behavior; S212, CFD model construction and verification: Based on the experimental data, a CFD model is constructed to simulate the mixing and settling process in the sludge tank; the prediction results of the CFD model are compared with the experimental data, and the model parameters are adjusted until the predetermined accuracy is achieved; S213, optimization of operation mode: agitation operation is performed by combining a mixed mode and a static mode, wherein in the optimization of the mixed mode, the operation time of the agitator is determined to achieve sufficient mixing of the sludge and prevent sedimentation; in the optimization of the static mode, the static sedimentation time of the sludge is determined to allow solid particles to settle to the bottom of the sludge tank; S214, energy consumption and efficiency analysis: Analyze the energy consumption of the agitator under different operating modes and find the operating point with the lowest energy consumption; improve the processing efficiency of the filter press and reduce energy consumption by adjusting the operating mode; S215: Model prediction and result evaluation: Use CFD model to predict the time of sludge load change to determine the optimal sludge treatment cycle; evaluate the efficiency of the filter press in different operation cycles and determine the optimal operation strategy for the operation mode.

[0046] In the S211 data collection step, in order to obtain a static sedimentation model of the sludge, sludge samples of different concentration ranges are obtained. Before each test, the initial sludge is thoroughly mixed in the test container to ensure uniform concentration during the filling process. In order to achieve different suspended solid concentrations while maintaining the properties of the sludge, the initial sample is diluted with the supernatant of the sludge. The height of the solid interface in the test container is measured and recorded regularly, and a sedimentation curve is drawn to obtain the average sedimentation velocity. Specifically, in order to identify the height of the solid interface, a fixed camera records the observation results at regular intervals. The raw data obtained at each measurement time point of the static sedimentation test at different concentrations are recorded and coupled to obtain the sedimentation velocity curve. The average sedimentation velocity is derived from the slope of the linear portion of the curve. In addition, since the sedimentation velocity is inversely proportional to the sludge concentration, that is, as the sludge is diluted, the sedimentation velocity will also increase. The mathematical sedimentation model is described using an equation to calculate the relationship between the sedimentation velocity and the concentration. The sedimentation velocity equation is expressed as: in X and are the concentration and average settling velocity of settleable solids, respectively. a , b and c is a model parameter obtained by fitting experimental data. This model assumes a nonlinear relationship between settling velocity and sludge concentration, where the settling velocity decreases as the concentration increases. This relationship is very important in sludge treatment because it affects the behavior of sludge in the sludge tank and the final treatment efficiency.

[0047] In order to obtain the effect of stirring on the sedimentation curve, a dynamic sedimentation model is further constructed. An electric motor is installed on the stirrer for adjusting the stirrer to different speeds. Sludge samples with different concentration ranges are obtained. The test container is filled with sludge to a predetermined height. After reaching the required angular velocity, stirring is continued for a certain time to ensure that the slurry and the equipment are stable under these conditions. After reaching a stable flow pattern, the stirrer is turned off to stop the circulation of the suspension. Under this operating condition, the interface height is scanned to accurately check the sedimentation behavior of the sludge. Repeat for other sludge concentrations and stirring speeds.

[0048] The construction and verification of the CFD model in step S212 is used to accurately simulate and optimize the mixing and settling process in the sludge tank. In this process, a three-dimensional CFD model was developed based on a laboratory-scale sludge settling experiment. The model simulates the flow and settling behavior of the sludge in the sludge tank in detail, where the physical properties of the sludge are set according to experimental data to reflect the rheological properties of the sludge. The geometry of the agitator is simplified to an infinitely thin circle in the model to reduce the computational complexity while ensuring an accurate description of the flow characteristics. This simplification is based on the main factors that affect the fluid flow in the actual operation of the agitator. A sensitivity analysis is performed by changing the grid size to ensure that the selected grid provides stable and accurate simulation results. This step is crucial to ensure the reliability of the model and reduce the consumption of computing resources. The boundary conditions of the model are set to reflect the actual operating conditions, including the wall conditions of the inlet and outlet, and the operating parameters of the agitator. The setting of these conditions is based on experimental observations and engineering experience. The physical properties of the sludge in the model, including viscosity and density, are set. Although the sludge exhibits non-Newtonian fluid properties, in the model, it is simulated based on the low viscosity characteristics when active mixing occurs. The finite volume method was used to discretize and solve the differential equations that control fluid flow and sedimentation. The accuracy of the model was verified by comparing the sludge interface height predicted by the CFD model with the experimental data. The deviation between the model prediction and the experimental data was controlled within a very small range. The model was further used to analyze the mixing uniformity and sedimentation behavior of the sludge in the sludge tank. By simulating the distribution of sludge volume fraction, the distribution of sludge in the sludge tank was evaluated, providing data support for optimizing operations.

[0049] A material balance was performed for the sludge as the solute in the sludge tank and a first-order system model was derived as follows: in F is the volume flow rate of the inlet and outlet flows, C Ai is the sludge concentration entering the sludge tank, C Ao is the sludge concentration leaving the sludge tank; VIt indicates the effective volume of the sludge tank, that is, the total volume of sludge in the sludge tank. t It is the unit time.

[0050] Two different non-steady-state operation modes, mixing mode and static mode, are defined in the CFD model to simulate the operation of the agitator and the settling of the sludge. In the present invention, the optimization of the operation mode is achieved by precisely controlling the operation time of the agitator and the settling time of the sludge, aiming to improve the sludge treatment efficiency and reduce energy consumption. Step S213 The optimization of the mixing mode involves determining the exact operation time of the agitator to ensure that the sludge is fully mixed in the sludge tank to prevent the formation of sediment, which is crucial to maintaining the uniformity of the sludge and improving the efficiency of subsequent treatment steps. In this mode, the operation of the agitator is set to start shortly after the sludge is deposited to re-suspend the deposited solids and ensure uniform distribution of the sludge. This operation mode is based on a deep understanding of the sludge settling behavior and precise control of the agitator's influence on fluid dynamics.

[0051] The optimization of the static mode involves determining the duration of static settling of the sludge after the agitator stops operating. This time period is selected based on experimental data and the prediction results of the CFD model in order to allow sufficient time for the solid particles to settle to the bottom of the sludge tank and separate the clear supernatant. This separation is essential for improving the quality of sludge treatment and reducing the solid content in subsequent treatment steps. In static mode, the settling behavior of the sludge is affected by gravity, while the cessation of the agitator reduces the turbulence caused by stirring, which helps the sedimentation of particles and the clarification process.

[0052] Through the simulation of CFD model, the influence of different stirring and settling time on sludge behavior is predicted, thus providing a scientific basis for the optimization of operation mode. The model predicts the distribution and settling velocity of sludge under specific stirring and settling cycles, and these data are used to guide the setting of actual operation mode. After the agitator runs for a period of time, the solid particles in the sludge will settle quickly, and the clarity of the supernatant will be significantly improved during the subsequent static period. The simulation of CFD model is crucial to determine the optimal operation time of the agitator and the settling time of the sludge.

[0053] In addition, the optimization of the operating mode also includes the control of an adjustable time-controlled shut-off valve upstream of the sludge tank to automatically adjust the rate of sludge discharge from the clarifier. This regulation, combined with the running and static cycles of the agitator, further improves the efficiency of sludge treatment. By accurately controlling the time when sludge flows into and out of the sludge tank, the concentration and settling effect of the sludge can be optimized, thereby improving the performance of the entire sludge treatment system. The present invention optimizes the operating mode of the sludge tank by accurately controlling the running time of the agitator and the settling time of the sludge. This optimization not only improves the efficiency of sludge treatment, but also reduces energy consumption, extends the service life of the equipment, and improves the overall performance of the sludge treatment process.

[0054] Step S214 is used to determine the operating point with the lowest energy consumption for the energy consumption of the agitator under different operating modes, and to optimize the processing efficiency of the filter press. First, by measuring the energy consumption of the agitator at different speeds and operating times, combined with the simulation results of the CFD model, the relationship between the energy consumption of the agitator and the uniformity of sludge mixing is analyzed. The CFD model provides the influence of the operation of the agitator on the sludge flow pattern and sedimentation behavior, thereby allowing a quantitative analysis of the relationship between the energy consumption of the agitator and the sludge treatment efficiency. The model predicts the distribution and sedimentation velocity of the sludge under specific stirring and sedimentation cycles, and these data are used to guide the design of the actual operating mode to minimize energy consumption. Further, the present invention optimizes the processing efficiency of the filter press by adjusting the operating mode, that is, defining two different non-steady-state operating modes-mixing mode and static mode. During the mixing mode, the agitator runs for a specific time to achieve sufficient mixing of the sludge and prevent the formation of sediment, and then enters the static mode to allow solid particles to settle to the bottom of the sludge tank. This periodic operating mode reduces the total operating time of the agitator, thereby significantly reducing energy consumption. In addition, the present invention also contemplates the operation of an adjustable time-controlled shut-off valve upstream of the sludge tank to automatically adjust the rate of sludge discharge from the clarifier. This adjustment, combined with the operation and rest periods of the agitator, further improves the efficiency of sludge treatment and reduces the treatment time of sludge in the filter press, thereby reducing energy consumption.

[0055] In step S215, the CFD model is used to predict the time of sludge load change to determine the optimal sludge treatment cycle, and to determine the optimal operation strategy of the operation mode by evaluating the efficiency of the filter press in different operation cycles. Using the CFD model, the dynamic behavior of sludge in the sludge tank is simulated, including the mixing and sedimentation processes. The model predicts the change of sludge volume fraction over time, which is crucial for determining the time when the sludge reaches the ideal concentration. By simulating the concentration change before and after the sludge enters the filter press, the time required for the sludge load to increase from a lower concentration to a higher concentration, and the time required to decrease from a higher concentration to a lower concentration can be predicted. These prediction results provide a scientific basis for determining the optimal cycle of sludge treatment. Further, the model prediction results are used to evaluate the efficiency of the filter press in different operation cycles. The filter press efficiency under different operation strategies is evaluated by simulating the influence of the operation and static cycle of the agitator on the sludge concentration distribution. The model predicts the time of sludge load change under a specific operation strategy, thereby allowing the operation and rest cycle of the filter press to be optimized.

[0056] In a specific embodiment, by combining experimental data and CFD model prediction, the agitator operation time is accurately set to 5 minutes, and the sludge static settling time is 50 to 60 minutes, including a 20-minute period without fresh sludge inflow and a subsequent 40-minute period of periodic inlet valve operation, to optimize sludge treatment efficiency and reduce energy consumption. Specifically, in the agitator operation mode, the agitator operates at a specific speed, which is determined based on experimental data and CFD model prediction results to achieve sufficient mixing of the sludge. Specifically, the agitator runs at a speed of 700 revolutions per minute (rpm) for 5 minutes to ensure that the sludge is evenly distributed in the sludge tank and prevent the formation of sediment. During these 5 minutes, the operation of the agitator ensures the uniformity of sludge mixing and provides uniform initial conditions for the subsequent settling process. When the sludge is statically settling, that is, after the agitator stops running, the sludge enters the static mode, and the settling time in this mode is crucial for the solid particles to settle to the bottom of the sludge tank. In static mode, the sludge is allowed to settle for 50 to 60 minutes, during which time the solid particles gradually settle to the bottom of the sludge tank under the action of gravity. During the initial 20 minutes, the inlet valve remains closed to prevent fresh sludge from entering the sludge tank and ensure that the sludge settles without interference. Subsequently, the inlet valve operates for 40 minutes with a cycle of 15 seconds open / 85 seconds closed, allowing the sludge to be discharged independently from the clarifier while facilitating the overflow of the supernatant.

[0057] Embodiment 5 Furthermore, the pressing process of the ultra-high pressure double diaphragm low temperature drying integrated machine of the present invention is a process of separating solids and liquids through a flexible diaphragm using water pressure, and the filter cake remains after water is removed from the sludge. The filter press is first a feeding process, a process of inserting the sludge into the filter chamber. The sludge is transported by a hydraulic high-pressure feed pump to start filtration. After the filtration is completed, the pressing process begins to achieve the final moisture content target of the filter cake. During this process, the filtrate is discharged from the filter press. Pressing time is the main target of control parameters related to energy efficiency. Obtaining the optimal value of pressing time is the key to saving energy and cost, and the optimal value of pressing time to achieve the final moisture content of the filter cake also depends on the filtrate. The filtrate changes over time during the pressing process until the dehydration is completed. As Fig.12 As shown, the filtrate is estimated based on image analysis, and then the optimal value of the pressing time is estimated.

[0058] Specifically, estimating the filtrate based on image analysis, and then estimating and automatically controlling the optimal value of the pressing time includes the following steps: S311, using a fixed camera to capture the image color of the filtrate discharged from the filter press; S312, performing denoising and contrast enhancement on the captured image to improve the accuracy of color analysis; S313, extracting color features in the HSV color space from the preprocessed image, and identifying the main color components in the image; S314, using linear regression to analyze the change trend of the filtrate color over time and identify the key moment of color change; S315, associating the color characteristics of the filtrate with the known concentrations of the chemical substances through a support vector machine model, and estimating the concentration of a specific chemical substance in the filtrate; S316. Use the Pearson correlation coefficient to determine the linear relationship between the change in filtrate color and the change in chemical concentration; S317, establishing a polynomial regression model to relate the filtrate color characteristics to the pressing time, and predicting the pressing time under a specific color change; S318. Monitor the changes in filtrate color in real time and use the color analysis results to adjust the operating parameters of the filter press to optimize the dewatering process; integrate color analysis and pressing time prediction into the automatic control device to achieve automatic adjustment of the sludge dewatering process.

[0059] The ultra-high pressure double diaphragm low temperature drying integrated machine of the present invention includes two stages of filtration and pressing for separating solids and liquids when working. The process uses two different pumps, a hydraulic high pressure feed pump for the filtration process and a pressure water pump for the pressing process. The first stage is started by inserting the sludge using the pressure of the sludge feed pump. During this process, the filtrate begins to be discharged and the moisture content of the filter cake gradually decreases. However, before the expected final moisture content is reached, the thickening rate of the filter cake decreases rapidly. In the second stage, pressing begins, and the water pressure of the pressure water pump is used to reduce the moisture content of the filter cake. In this stage, the sludge feed pressure is reduced. During the pressing process, the filtrate decreases over time until it stops. During the pressing time, a visible light camera is installed to capture the filtrate.

[0060] In the S311 image capture step, the capture cycle is set to measure once per minute, and 60 images are captured for a single capture cycle. Blurred images are excluded because the filtrate may not be clearly seen in the image. Before starting to squeeze, the camera also captures an image without filtrate in the picture for reference.

[0061] In the step of preprocessing the captured image in S312, a denoising algorithm is applied to eliminate random noise in the image, which comes from the sensor, environmental interference or compression loss during image transmission, so as to obtain clearer image details; then a contrast enhancement operation is performed to adjust the brightness and contrast level of the image so that the subtle differences in the filtrate color are more obvious and the color distinction in the image is enhanced, which is crucial for subsequent color feature extraction and analysis because it directly affects the accuracy of color analysis and the optimization effect of the sludge dewatering process.

[0062] In step 313, color feature extraction, the image is converted from the RGB color space to the HSV color space to separate color and brightness information. The HSV color histogram is calculated, with particular attention paid to the hue (H) channel, to identify the main color components in the image. The histogram is analyzed to determine the hue value of each main color, and a threshold range is set to identify and track these colors. The hue value of each main color is quantified, and its distribution and frequency in the image are recorded to provide basic data for color change analysis.

[0063] In step 314, color change analysis, images of the filtrate during the sludge dewatering process are captured periodically and HSV color features are extracted from them. A time series data set of the filtrate color is constructed to record the changes in the filtrate color over time. Linear regression is used to analyze the trend of these color features over time and identify color changes. Using a change point detection algorithm to identify key moments of color change, indicating changes in sludge treatment conditions or turning points in the dewatering process, is essential for optimizing the dewatering process and adjusting operating parameters.

[0064] In step 315, chemical component concentration estimation, filtrate samples with known chemical concentrations and their color features are collected through laboratory analysis. These data are used to train a support vector machine model to associate color features with chemical concentrations. After the model training is completed, its accuracy is verified on an independent test set to ensure the reliability of the prediction results. The trained model is applied to the real-time captured filtrate images to predict the concentration of chemicals in the sludge, providing a scientific basis for the optimization of the sludge dewatering process.

[0065] In step 316, the linear relationship between the change in filtrate color and the change in chemical concentration is determined by calculating the Pearson correlation coefficient. This coefficient measures the degree of linear correlation between two variables, and its value is between -1 and 1, where 1 indicates a perfect positive correlation, -1 indicates a perfect negative correlation, and 0 indicates no correlation. First, collect the filtrate color characteristic data and the corresponding chemical concentration data to form a paired data set. Next, calculate the mean and standard deviation of the filtrate color characteristic and chemical concentration data respectively; calculate the covariance between the two variables to reflect the joint change trend of the two variables. Use the following formula to calculate the Pearson correlation coefficient r : in, x i and y i are the observed values ​​of the filtrate color characteristics and chemical concentrations, and is their mean, n is the number of observations. Based on the calculated Pearson correlation coefficient, the strength and direction of the linear relationship between the filtrate color change and the chemical concentration change are explained. By quantitatively analyzing the correlation between the filtrate color change and the chemical concentration change, a basis is provided for the optimization of the subsequent sludge dewatering process.

[0066] The purpose of the correlation analysis is to determine if there is a linear relationship between the change in filtrate color and the change in chemical concentration. The degree of this linear relationship is quantified by calculating the Pearson correlation coefficient. This step provides a basis for understanding the chemical dynamics behind the color change and helps identify which chemicals have a significant effect on the color change. If the change in filtrate color is caused by a change in chemical concentration, then there is an indirect relationship between the color change and the pressing time. After confirming this relationship through correlation analysis, a regression model is used to predict the pressing time.

[0067] After confirming that there is a linear relationship between the filtrate color change and the chemical concentration, the next step is to establish a polynomial regression model to link the filtrate color characteristics to the pressing time. The purpose of this model is to predict the pressing time required under a specific color change, thereby optimizing the dehydration process. This model assumes that the change in filtrate color is a predictor of pressing time. Specifically, in step 317, a polynomial regression model is established to link the filtrate color characteristics to the pressing time to predict the pressing time under a specific color change; including: collecting filtrate color characteristic data and corresponding pressing time data to form a paired data set. Select a polynomial regression model that captures the nonlinear relationship between the filtrate color characteristics and the pressing time. Use the least squares method to fit the data and determine the parameters of the polynomial regression model. The model form is: in y is the pressing time (dependent variable), x is the filtrate color characteristic (independent variable), β 0 is y Axis intercept, m is the degree of the polynomial, β m yes x m The slope coefficient of the regression model was calculated by dividing the data set into a training set and a test set. The model was fitted using the training set data, and then the prediction performance of the model was evaluated on the test set. According to the model validation results, the degree of the polynomial or the model parameters were adjusted to optimize the prediction accuracy of the model. The optimized polynomial regression model was used to predict the pressing time based on the filtrate color characteristics, and the prediction results were applied to the automated control of the sludge dewatering process.

[0068] In the real-time monitoring and adjustment step 318, a real-time image of the filtrate is captured by high-precision sensors and image processing technology, and color features are extracted from it. These color feature data are then used to analyze the color change trend of the filtrate and compare it with the preset color threshold to evaluate the effect of the current dehydration process. Based on the color analysis results, the operating parameters of the filter press, such as pressure and filtration rate, are automatically adjusted to achieve a more efficient dehydration effect and ensure that the sludge treatment process operates under optimal conditions.

[0069] Integrate color analysis and pressing time prediction technology into the automatic control device to achieve automatic regulation of the sludge dewatering process. The system integrates a polynomial regression model to predict the required pressing time based on the real-time monitored filtrate color characteristics and automatically adjusts the filter press operating parameters to adapt to the predicted results. This integrated approach improves the automation level of the sludge dewatering process, reduces manual intervention, and improves treatment efficiency and sludge dewatering quality. In this way, the automatic control device responds to changes in the sludge dewatering process in real time, ensuring that the dewatering process is always in an optimal state.

[0070] The preferred embodiments of the present invention are described above. Therefore, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A low-energy consumption sludge high-drying dehydration and low-temperature drying system, characterized in that: include: A sludge tank (20), a sludge sonic conditioner, an automatic dosing device (40), a hydraulic high-pressure feed pump (30), an ultra-high-pressure double-diaphragm low-temperature drying integrated machine (100), a vacuum pump (50), a filter plate cleaning device (90), a condenser (60), an electromagnetic heating device, a heat exchanger (70), an insulation water tank (80), a screw conveyor, a dry material bin and an automatic control device; wherein: The sludge tank (20) is used to temporarily store the sludge pumped from the sludge pool; the sludge sonic conditioner is arranged in the sludge pool and is used to pre-treat the sludge and destroy the flocculation structure in the sludge by using sonic waves; the automatic dosing device (40) automatically adds flocculants or other chemicals to the sludge pool through the dosing pipeline; the hydraulic high-pressure feed pump (30) conveys the conditioned sludge from the sludge tank to the ultra-high pressure double diaphragm low-temperature drying all-in-one machine (100) through the sludge inlet pipe; the ultra-high pressure double diaphragm low-temperature drying all-in-one machine (100) integrates high-pressure filtering, high-pressure diaphragm squeezing, and low-temperature vacuum drying functions; the vacuum pump (50) creates a negative pressure environment for the ultra-high pressure double diaphragm low-temperature drying all-in-one machine, reduces the boiling point of water in the filter cake, and promotes water evaporation; the condenser (60) is used to cool the water vapor discharged from the vacuum pump and recover heat; the electromagnetic heating device , providing heat energy for the ultra-high pressure double diaphragm low temperature drying integrated machine for heating sludge or maintaining temperature; an insulated water tank (80), connected to the ultra-high pressure double diaphragm low temperature drying integrated machine (100) via a pressing water inlet pipe and a pressing water return pipe; a heat exchanger (70), externally connected to the steam heat energy of the plant area, and exchanging heat with the insulated water tank (80) via a heat exchange circulation pipeline; a screw conveyor, located at the bottom of the ultra-high pressure double diaphragm low temperature drying integrated machine (100), for conveying the dehydrated dry sludge to the dry material bin; the dry material bin, for storing the dehydrated dry sludge; a filter plate cleaning device (90), integrated in the ultra-high pressure double diaphragm low temperature drying integrated machine (100), for cleaning the filter plate after the filter plate completes sludge dehydration, and removing the sludge residue on the filter cloth; an automatic control device for obtaining sensor data and automatically controlling the operation of the low energy consumption sludge high-drying dehydration low temperature drying system.

2. A low-energy sludge high-drying dehydration and low-temperature drying system as claimed in claim 1, characterized in that: The filter plate cleaning device (90) comprises: a driving mechanism (1), the driving mechanism (1) driving a pulley (10) to rotate; a supporting mechanism (2), supporting and stabilizing the overall structure of the cleaning machine; a guide wheel (4), rotatably mounted on the supporting mechanism (2), assisting the lifting mechanism (3) in guiding when moving; a flushing mechanism (5), comprising a water inlet pipe (8), a water pipe (15) and a nozzle (17), the water inlet pipe (8) being a water source input channel of the flushing mechanism (5), and the nozzle (17) being connected to the water inlet pipe (8) via the water pipe (15); a lifting mechanism (3), driven by a lifting motor (6), and driving the flushing mechanism (5) to move vertically; a lifting sensor (7), fixedly mounted on one side of the supporting mechanism (2); and a level sensor (9), fixedly mounted on the upper side of the driving mechanism (1).

3. A low-energy sludge high-drying dehydration and low-temperature drying system as claimed in claim 2, characterized in that: The driving mechanism (1) comprises a driving motor (11), a bevel gear and a pulley (10); the driving motor (11) drives the pulley (10) to rotate via the bevel gear; the two pulleys (10) are connected via a belt drive; and the lifting motor (6) drives the lifting mechanism (3) to move via a steel wire rope.

4. A low-energy sludge high-drying dehydration and low-temperature drying system as claimed in claim 3, characterized in that: The lifting mechanism (3) comprises a fixing frame and a sliding block (13); the sliding block (13) is arranged at the connection between the lifting mechanism (3) and the supporting mechanism (2); and the water inlet pipe (8) is fixedly mounted inside the fixing frame.

5. A low-energy consumption sludge high-speed dehydration and low-temperature drying control method, using the low-energy consumption sludge high-speed dehydration and low-temperature drying system according to any one of claims 1 to 4, characterized in that: The following steps are involved: S111. Sludge pretreatment: Use a sludge sonic conditioner to pretreat the sludge to destroy the flocculation structure in the sludge; add flocculants or other chemicals to the sludge through an automatic dosing device; S112, sludge transportation: use a hydraulic high-pressure feed pump to transport the conditioned sludge from the sludge tank to the ultra-high pressure double diaphragm low-temperature drying integrated machine; S113, sludge dehydration: the sludge is further dehydrated in the ultra-high pressure double diaphragm low temperature drying machine; The electromagnetic heating device provides heat energy to the ultra-high pressure double diaphragm low temperature drying machine; at the same time, the vacuum pump is started, and the water vapor generated during the dehydration process is pumped out by the vacuum pump and cooled by the condenser to recover heat; S114, dry sludge transportation and storage: the dehydrated dry sludge is transported to the dry material silo for storage through a screw conveyor; S115, filter plate cleaning: start the filter plate cleaning device to clean the filter plate and remove the sludge residue on the filter cloth.

6. A low-energy sludge high-drying dehydration and low-temperature drying control method as claimed in claim 5, characterized in that: In step S13, after the sludge enters the machine, it first undergoes a high-pressure filtration stage, using an ultra-high-pressure double-diaphragm filter plate for double-sided extrusion tympanic membrane filtration; hot water is introduced to heat the sludge in the filter chamber, and the vacuum pump is started at the same time; when the vacuum pump is working, the filter chamber is in a negative pressure state, and the boiling point of the water in the filter cake is reduced under the negative pressure state; the heat source is continuously circulated and input, and the vacuum pump continuously removes water vapor until the water content of the filter cake is dried to below the predetermined moisture content.

7. A low-energy sludge high-drying dehydration and low-temperature drying control method as claimed in claim 6, characterized in that: According to the saturation of the filter press, the hydraulic high-pressure feed pump automatically adjusts the pressure and flow, and automatically switches the working mode at different stages, including low-pressure and high-speed, medium-pressure and medium-speed, and high-pressure and low-speed modes.

8. A low-energy sludge high-drying dehydration and low-temperature drying control method as claimed in claim 7, characterized in that: In the process of entering the medium-pressure and medium-speed stage from the low-pressure and high-speed stage, the filling degree of the filter chamber is first monitored, and after reaching the preset first filling threshold; the pressure change is monitored, when the pressure rises from the initial value to the preset first pressure threshold; after the first two conditions are met, the filtration speed is monitored, and when the speed drops below the preset first flow threshold, if all three conditions are met within the set first time threshold, the hydraulic high-pressure feed pump automatically switches from the low-pressure and high-speed stage to the medium-pressure and medium-speed stage; In the process of entering the high-pressure and low-speed stage from the medium-pressure and medium-speed stage: first, monitor the filling degree of the filter chamber when it reaches the preset second filling threshold; monitor the pressure rise rate when it exceeds the preset second pressure threshold; monitor the filtration rate when it drops below the preset second flow threshold; after the first three conditions are met, monitor the filter cake thickness or density when it reaches the preset first thickness or first density threshold; monitor the filtrate clarity when the filtrate transmittance reaches above the preset first transmittance threshold. If all five conditions are met within the set second time threshold, the hydraulic high-pressure feed pump automatically switches from the medium-pressure and medium-speed stage to the high-pressure and low-speed stage.

9. A low-energy sludge high-drying dehydration and low-temperature drying control method as claimed in claim 8, characterized in that: At least two agitators are arranged in the sludge tank. The agitators are equipped with at least three blades and are installed on the vertical wall of the sludge tank. The CFD model is used to obtain the optimal agitator operating parameters. The specific steps are as follows: S211. Data collection: Conduct static sedimentation experiments to obtain sedimentation velocity data at different sludge concentrations; conduct dynamic sedimentation experiments under controlled stirring speed to observe the effect of stirring on sedimentation behavior; S212, CFD model construction and verification: Based on the experimental data, a CFD model is constructed to simulate the mixing and settling process in the sludge tank; the prediction results of the CFD model are compared with the experimental data, and the model parameters are adjusted until the predetermined accuracy is achieved; S213, optimization of operation mode: agitation operation is performed by combining a mixed mode and a static mode, wherein in the optimization of the mixed mode, the operation time of the agitator is determined to achieve sufficient mixing of the sludge and prevent sedimentation; in the optimization of the static mode, the static sedimentation time of the sludge is determined to allow solid particles to settle to the bottom of the sludge tank; S214, energy consumption and efficiency analysis: Analyze the energy consumption of the agitator under different operating modes and find the operating point with the lowest energy consumption; improve the processing efficiency of the filter press and reduce energy consumption by adjusting the operating mode; S215: Model prediction and result evaluation: Use CFD model to predict the time of sludge load change to determine the optimal sludge treatment cycle; evaluate the efficiency of the filter press in different operation cycles and determine the optimal operation strategy for the operation mode.

10. A low energy consumption sludge high-drying dehydration and low-temperature drying control method as claimed in claim 9, characterized in that: The filtrate is estimated based on image analysis and the optimal value of the pressing time is estimated and automatically controlled, including the following steps: S311, using a fixed camera to capture the color of the filtrate image discharged from the filter press; S312, performing denoising and contrast enhancement on the captured image to improve the accuracy of color analysis; S313, extracting color features in the HSV color space from the preprocessed image, and identifying the main color components in the image; S314, using linear regression to analyze the change trend of the filtrate color over time and identify the key moment of color change; S315, associating the color characteristics of the filtrate with the known concentrations of the chemical substances through a support vector machine model, and estimating the concentration of the specific chemical substance in the filtrate; S316. Use the Pearson correlation coefficient to determine the linear relationship between the change in filtrate color and the change in chemical concentration; S317, establishing a polynomial regression model to relate the filtrate color characteristics to the pressing time, and predicting the pressing time under a specific color change; S318. Monitor the changes in filtrate color in real time and use the color analysis results to adjust the operating parameters of the filter press to optimize the dewatering process; integrate color analysis and pressing time prediction into the automatic control device to achieve automatic adjustment of the sludge dewatering process.

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