Sludge dewatering device of van type plate-and-frame filter press

Abstract

The utility model discloses a sludge dewatering device of a van type plate-and-frame filter press, which comprises a rack, a filter plate group and a pressing mechanism, and an automatic sludge scraping component is arranged at the bottom of the filter plate group. The structure comprises a mud scraping plate which horizontally reciprocates on a rack guide rail, a guide support rod connected with the mud scraping plate and a chain transmission mechanism linked with the guide support rod, sectional type elastic scraping pieces are arranged on the bottom face of the mud scraping plate, and all the sections of the scraping pieces are hinged through pin shafts to form an adjustable mud scraping working face. The problems of filter plate damage and sludge residue caused by rigid contact of a traditional sludge scraping device are solved by arranging an automatic sludge scraping assembly above a filter plate group and a linkage structure of the automatic sludge scraping assembly and adopting a collaborative operation form of a guide rail guided sludge scraping plate and a chain transmission mechanism; in addition, by means of the hinged structure and the thickness gradual change design of the sectional type elastic scrapers and through the dynamic force compensation mechanism of the adjacent scrapers, the defect of uneven scraping caused by the uneven surface of the filter plate is overcome, and the sludge treatment efficiency is effectively improved.

Description

Technical Field

[0001] This utility model relates to sludge dewatering devices, and more particularly to a sludge dewatering device for a chamber plate and frame filter press. Background Technology

[0002] With rapid industrialization and urbanization, the amount of sludge generated during wastewater treatment is constantly increasing. This sludge contains a large amount of harmful substances, and if not properly treated, it will cause serious environmental pollution. Traditional sludge treatment methods suffer from low efficiency, high cost, and significant environmental risks. High-pressure plate and frame dewatering technology can effectively solve these problems and improve the overall effectiveness of sludge treatment. The state is increasingly emphasizing sludge treatment and disposal, and has successively introduced a series of policies and regulations to encourage innovation and application of sludge treatment technologies. Through high-pressure plate and frame dewatering technology, the volume and moisture content of sludge are significantly reduced, achieving sludge reduction and facilitating subsequent resource utilization such as brick making and fertilizer production.

[0003] For example, the "High-efficiency and low-consumption sludge high-pressure deep dewatering machine" disclosed in Chinese patent literature, application number "CN201310352861.1", has slide rails fixed on both sides of the hydraulic device and the filter press device. The front end of the hydraulic device is provided with a push rod, which is fixed together with the push plate. The push plate is movably installed on the slide rail. The rear seat is provided with a feeding hole. The filter press plate is movably installed on the slide rail. The outer frame of the movable plate and the movable plate are fixed together. The fixed plate and the movable plate are sealed and movably connected. The outer frame of the movable plate and the movable plate are provided with interconnected multi-channel water guide holes and water discharge holes. A porous stainless steel mesh pad is installed in the groove on one side of the movable plate. The fixed plate is provided with a material cavity. The movable plate has a feed hole communicating with the material cavity. An elastic device groove is opened at the position opposite to the inner edge of the fixed plate and the outer frame of the movable plate. An elastic device is installed in the groove. The filter cloth is attached to the surface of the fixed plate, the stainless steel mesh pad, the movable plate, the outer frame of the movable plate and the inner surface of the feed hole.

[0004] The above-mentioned solutions improve the sludge moisture content and energy consumption, but the effect is limited, and the sludge cleaning efficiency is still not ideal, so there is room for improvement. Utility Model Content

[0005] To address the issue of unsatisfactory sludge removal efficiency in existing sludge dewatering devices mentioned in the background section, this paper proposes an automatic sludge scraping assembly and its linkage structure above the filter plate assembly. This assembly utilizes a guide rail-guided scraper and a chain drive mechanism in a coordinated operation, solving the problems of filter plate damage and sludge residue caused by rigid contact in traditional scraping devices. Furthermore, by employing the articulated structure and gradually varying thickness design of segmented elastic scrapers, and through a dynamic force compensation mechanism between adjacent scrapers, the paper overcomes the uneven scraping defects caused by uneven filter plate surfaces, effectively improving sludge treatment efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A sludge dewatering device for a chamber-type plate and frame filter press includes a frame, a filter plate assembly, and a pressing mechanism. The bottom of the filter plate assembly is equipped with an automatic sludge scraping component. This structure includes a scraper that moves horizontally back and forth on the frame guide rail, a guide support rod connected to the scraper, and a chain transmission mechanism linked to the guide support rod. The bottom surface of the scraper is provided with segmented elastic scrapers, and each segment of the scraper is hinged by a pin to form an adjustable sludge scraping working surface.

[0008] The automatic sludge scraping assembly achieves precise motion control through a combination of guide rails and chain drives. The guide rails define the horizontal movement trajectory of the scraper blades, while the chain drive mechanism provides stable driving force. Together, they create a uniform, linear scraping path on the bottom of the filter plate. The articulated structure of the segmented elastic scraper blades allows them to adaptively adjust their angle according to the unevenness of the filter plate surface during operation. When a section of the scraper blade encounters localized sludge accumulation, adjacent scraper blades transmit force through pins, creating a coordinated compensation. This dynamic adjustment mechanism effectively avoids the jamming phenomenon caused by excessive local resistance in traditional rigid scrapers.

[0009] Preferably, the bottom working surface of the segmented elastic scraper maintains linear contact with the drop tray at an inclination angle of 2-3°.

[0010] Preferably, the chain drive mechanism includes a double-row synchronous chain, which engages with a drive block at the end of the guide support rod via a transition sprocket. The double-row synchronous chain transmission structure offers better load distribution characteristics compared to a single-row chain, and the optimized arrangement of the transition sprockets improves the chain wrap angle, increasing transmission efficiency while reducing the risk of chain slippage.

[0011] Preferably, an anti-deviation limiting component is provided between the guide support rod and the frame guide rail. The anti-deviation limiting component includes a U-shaped groove fixed on the frame and a polytetrafluoroethylene (PTFE) slider embedded in the groove. The cooperation between the PTFE slider and the U-shaped groove in the anti-deviation limiting component ensures the freedom of movement of the guide support rod, and reduces frictional loss through the self-lubricating properties of the polymer material, thus ensuring long-term operational stability.

[0012] Preferably, the top of the scraper is connected to a sludge thickness detection element, which consists of a pressure-sensing spring and a contact probe, with the probe tip extending 5-8 mm above the drop tray.

[0013] Preferably, the contact probe is connected to the relay module of the electrical control cabinet via a signal line, and the relay module is equipped with a mud scraping frequency adjustment knob.

[0014] Preferably, the segmented elastic scraper uses a polyurethane board with a gradually varying thickness, with the thickness continuously varying within the range of 5-15mm.

[0015] Preferably, the guide support rod is covered with a glass fiber reinforced nylon protective layer, and a cooling channel is provided inside the rod and connected to the coolant outlet of the hydraulic station via a hose.

[0016] Therefore, this utility model has the following beneficial effects:

[0017] The articulated structure of the segmented elastic scraper compensates for the unevenness of the filter plate surface through force transmission between adjacent scrapers, improving the adhesion of the sludge scraping working surface to over 90%, effectively eliminating the vibration caused by sudden changes in local resistance in traditional rigid scrapers, and reducing the load fluctuation of the drive mechanism by up to 35%.

[0018] The combination of double-row synchronous chain and transition sprocket increases the chain wrap angle to 120°, and the increased number of contact teeth reduces the single-tooth load by 40%. The cooling channel of the guide support rod keeps the continuous operating temperature of the transmission system stable within 60°C, extending the chain service life by 2.3 times.

[0019] The PTFE slider and the U-shaped groove form a self-lubricating interface, reducing the coefficient of friction to below 0.04. Combined with the thickness-gradient scraper, the maintenance cycle of the sludge scraping assembly is extended from 150 hours to 500 hours, and the overall energy efficiency of the equipment is improved by 28%.

[0020] The closed-loop feedback mechanism between the sludge thickness detection device and the electrical control cabinet adjusts the sludge scraping frequency in real time. When the sludge layer thickness exceeds 8mm, the sludge scraping operation is automatically triggered. Compared with the timed scraping scheme, the number of ineffective scrapings is reduced by 42%, and the wear rate of the scraper blades and energy consumption are reduced by 17%. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] Figure 2 This is a structural schematic diagram of the anti-deviation limiting component in this utility model.

[0023] In the diagram: 1. Frame; 11. Frame guide rail; 2. Filter plate assembly; 3. Pressing mechanism; 4. Drop tray; 5. Automatic sludge scraping assembly; 51. Sludge scraper; 511. Segmented elastic scraper; 512. Pin shaft; 52. Guide support rod; 521. Drive block; 53. Chain drive mechanism; 531. Double row synchronous chain; 54. Anti-deviation limit assembly; 541. U-shaped slot; 542. PTFE slider; 55. Sludge thickness detection component; 551. Contact probe; 553. Signal line; 6. Electrical control cabinet; 7. Hydraulic station. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figure 1 As shown in Figure 2, a sludge dewatering device for a chamber-type plate and frame filter press includes a frame 1, a filter plate assembly 2, and a pressing mechanism 3. An automatic sludge scraping assembly 5 is configured at the bottom of the filter plate assembly. The automatic sludge scraping assembly 5 includes a scraper 51 that moves horizontally back and forth on the frame guide rail 11, a guide support rod 52 connected to the scraper, and a chain transmission mechanism 53 that is linked to the guide support rod. The bottom surface of the scraper is provided with segmented elastic scraper blades 511, and each segment of the scraper blade is hinged by a pin 512 to form an adjustable scraping working surface.

[0027] In this embodiment, the sludge dewatering device achieves efficient sludge scraping operations. The core of this capability lies in the precise coordination between the automatic scraping assembly and the transmission system located above the filter plate assembly. The main body of the device consists of a frame supporting the filter plate assembly and a clamping mechanism. The filter plate assembly comprises alternating fixed and movable filter plates forming a trapezoidal sludge chamber. The scraping assembly moves horizontally along the frame guide rails, its path perfectly parallel to the length of the filter plate assembly, ensuring that the scraping working surface covers the entire filter plate area. Segmented elastic scrapers on the bottom surface of the scraper are hinged via pins to form a continuously adjustable working surface. Each scraper segment uses a polyurethane sheet with a gradually decreasing thickness along the scraping direction from the fixed end to the free end. This allows the scraper to undergo gradient deformation when subjected to sludge resistance, maintaining overall scraping rigidity while possessing localized elastic deformation capabilities. The connection point between the guide support rod and the scraper blade is set at the projection position of the scraper blade's center of gravity. The glass fiber reinforced nylon layer covering the surface of the rod forms a wear-resistant protective interface. The internal cooling channel is set through the rod axis and forms a circulation loop with the coolant outlet of the hydraulic station 7 through the hose, thereby effectively dissipating the frictional heat energy generated by the operation of the transmission system.

[0028] The chain drive mechanism employs a combination of a double-row synchronous chain 531 and a transition sprocket. The chain pitch is precisely matched to the tooth profile of the drive block 521. The curvature radius design of the transition sprocket ensures that the chain wrap angle reaches the optimal transmission angle. The double-row structure evenly distributes the load to the chain links on both sides, significantly reducing stress concentration on one side of the chain. The drive block and the guide support rod end are connected by a tenon and mortise joint, and triangular reinforcing ribs are set on the contact surface to improve torsional resistance. The U-shaped groove 541 of the anti-deviation limiting component 54 has a guide groove machined on its inner wall. The PTFE slider 542 has protrusions on both sides that mate with the groove, forming a three-dimensional constraint while retaining axial movement freedom. The gap between the slider and the groove is controlled within the allowable range of thermal expansion to ensure that the guiding accuracy is not affected by temperature changes.

[0029] The contact probe 551 of the sludge thickness detection component 55 adopts a stepped shaft structure. The tapered detection head at the front end and the preload of the pressure sensing spring form a closed-loop control of the contact pressure. When the probe tip contacts the sludge layer above the drop tray 4, the change in spring compression is converted into an electrical signal output. The signal line 553 adopts a double-layer shielding structure, with an outer layer of braided copper mesh and an inner layer of aluminum foil forming a composite shielding layer, effectively suppressing electromagnetic interference generated by the hydraulic system. The relay module in the electrical control cabinet 6 is equipped with a sludge scraping frequency adjustment knob, which uses a pulse width modulation circuit to control the motor speed, achieving stepless adjustment of the sludge scraping cycle within the range of 10-300 seconds.

[0030] During operation, the clamping mechanism presses the filter plate assembly into a sealed chamber. After the sludge is dewatered under high pressure, the movable filter plate separates from the fixed filter plate during the resetting process. At this time, the scraping assembly moves along the guide rail to the starting end of the filter plate assembly. After the scraping program is started, the chain drive mechanism drives the guide support rod to advance at a constant speed. The segmented scraper blades on the bottom surface of the scraper plate form a linear contact with the filter plate surface at an inclination angle of 2-3°. This angle range allows the leading edge of the scraper blade to generate a moderate cutting force, while the trailing edge forms a peeling zone to prevent sludge adhesion. When the scraper blade encounters local residual sludge, the hinged structure allows adjacent scraper blades to deflect relative to each other. Through force transmission, the scraping force is dynamically balanced, avoiding the jamming phenomenon caused by excessive local resistance in traditional integral scraper blades. The thickness-gradient structure increases the moment of inertia of the section at the root of the scraper blade where it bears the maximum bending moment, effectively reducing the stress peak. Combined with the high elastic modulus of polyurethane material, the fatigue life of the scraper blade is increased to more than three times that of traditional rubber scraper blades.

[0031] The sludge thickness detection system monitors the sludge accumulation height at the drop tray in real time using a contact probe. When the detected thickness exceeds a set threshold, the control system automatically triggers a sludge scraping operation. The tapered structure at the probe tip generates a gradual pressure change upon contact with the sludge layer. The linear characteristic of the pressure-sensing spring converts the mechanical displacement into a precise electrical signal. This signal is filtered, amplified, and then input to the PLC controller, forming a closed-loop control circuit. Compared to time-based control, this feedback mechanism reduces ineffective scraping actions by more than 30% and lowers the scraper wear rate. Hydraulic oil circulating in the cooling channel of the guide support rod promptly dissipates frictional heat. Combined with the heat insulation effect of the surface protective layer, this keeps the rod's operating temperature below the material's thermal deformation critical point, ensuring long-term stability of transmission accuracy.

[0032] This sludge dewatering device achieves automated operation through multi-system collaboration. The operation begins with the filter plate assembly compaction stage. After the operator starts the hydraulic station, the compaction mechanism drives the movable filter plates to move towards the fixed filter plates until a sealed chamber is formed. At this time, the high-pressure pump injects sludge into the chamber, maintaining the injection pressure within the range of 0.8-1.2 MPa to ensure full filling. When the pressure sensor detects that the pressure inside the chamber reaches the set threshold, the system automatically switches to the pressure holding stage. During this process, the sludge achieves solid-liquid separation under the action of the filter cloth. The filtrate enters the subsequent treatment unit through the guide channel, while the sludge cake adheres to the surface of the filter plates. After the dewatering cycle is completed, the compaction mechanism performs a reset action, and the movable filter plates smoothly retreat under the guidance of the guide columns. At this time, a 5-10 cm working gap is formed between the filter plate assemblies, providing operating space for the sludge scraping assembly.

[0033] When the sludge scraping operation starts, the electrical control cabinet first detects the thickness of the sludge accumulation at the drop tray using contact probes. When the detected value exceeds the preset 5mm critical point, the relay module sends a start signal to the transmission system. Driven by a motor, the chain drive mechanism moves the guide support rod along the frame guide rail at a constant speed. Initially, the scraper blade approaches the edge of the filter plate assembly at a low speed (0.1m / s), increasing its speed to the working speed (0.3m / s) after contact with the filter plate surface. During the scraper's movement, the segmented elastic scraper blades form a 2-3° inclined contact angle with the filter plate surface. This angle design generates a moderate cutting force at the leading edge of the scraper blade, while the trailing edge forms a peeling zone to prevent secondary sludge adhesion. When a section of the scraper blade encounters a thicker local sludge layer, the elastic deformation of the polyurethane material allows that section of the scraper blade to deflect upwards by 3-5°. At this time, adjacent scraper blades transmit force through pins to form a linkage compensation, ensuring a balanced distribution of the overall scraping force.

[0034] The double-row synchronous chain of the transmission system forms a 120° wrap angle under the guidance of the transition sprocket. This angle increases the number of contact teeth between the chain and the sprocket to 8-10 teeth, significantly reducing the load on a single tooth. The cooling channel inside the guide support rod circulates hydraulic oil at a flow rate of 0.5L / min. The oil temperature is controlled below 40℃ by a heat exchanger to ensure that the thermal expansion of the rod does not exceed the accuracy requirement of 0.05mm / m. The PTFE slider of the anti-deviation limiting component generates a micron-level gap change with the U-shaped groove during operation. This dynamic fit achieves self-adjustment through the low friction characteristics of the material (μ<0.05). When the ambient temperature rises and causes the frame to expand, the slider can compensate for the displacement of 0.1-0.2mm along the length of the groove by 0.1-0.2mm, avoiding structural stress concentration.

[0035] The sludge thickness detection system continuously monitors the displacement signal of the contact probe during sludge scraping. When the probe rebounds due to the decrease in sludge layer thickness, the deformation of the pressure-sensing spring is converted into a 4-20mA current signal and transmitted to the PLC controller. The control system dynamically adjusts the scraping frequency based on the signal change rate. For example, if the sludge thickness decreases at a rate exceeding 15% over three consecutive scraping cycles, the scraping interval is automatically extended by 30%, thereby optimizing energy efficiency. The double-layer shielding structure of the signal line suppresses high-frequency interference of 30-50kHz generated by the hydraulic system, ensuring a detection accuracy error of less than ±0.5mm.

[0036] In industrial applications, the operating parameters of this device need to be adjusted according to the characteristics of the sludge. When treating primary sludge with a moisture content of over 85%, the scraping speed should be set at 0.25 m / s. At this speed, the contact pressure between the scraper and the filter plate should be controlled within the range of 200-300 N / m², which can effectively remove the sludge cake while avoiding excessive wear of the scraper. For activated sludge with a high fibrous content, the speed should be reduced to 0.15 m / s and the contact pressure increased to 400 N / m². At the same time, the cooling system of the guide support rod should be turned on to cope with the increased frictional heat load. During installation, the levelness of the frame needs to be calibrated to within 0.1 mm / m, which is achieved using a laser level and fine-tuning anchor bolts. This precision requirement stems from the sensitivity of the chain drive mechanism to the parallelism of the tracks. When the flatness deviation between the two guide rails exceeds 0.3 mm, the load distribution imbalance of the double-row chains will exceed 15%, leading to premature fatigue fracture of one side of the chain. The assembly of the filter plate assembly must follow the principle of alternating arrangement of "fixed-moving-fixed". The spacing error between adjacent filter plates should be controlled within ±0.5mm to ensure that the sealing flange is fully fitted when pressed. This assembly accuracy is guaranteed by a special positioning fixture. The fit clearance between the V-shaped positioning groove of the fixture and the guide edge of the filter plate is designed to be 0.05-0.1mm.

[0037] In oily sludge treatment scenarios, a steam injection device needs to be installed in front of the scraper. This device consists of an array of stainless steel tubes with a diameter of 8mm and a spacing of 50mm. Saturated steam at a pressure of 0.4MPa and a temperature of 120℃ is injected at a 45° angle onto the filter plate surface to soften the oily substances for easier scraping. The steam injection time is linked to the scraper action. The injection starts 2 seconds before the scraper reaches the end of the filter plate and continues until the scraper has completely passed through the area, then stops 1 second later. This timing parameter is calculated using the heat conduction equation to ensure that the surface temperature of the filter plate does not rise by more than 25℃ to avoid thermal deformation. In this case, the glass fiber reinforced nylon protective layer of the guide support rod needs to be treated with a silane coupling agent to increase its surface contact angle from 75° to 110°, effectively preventing material expansion caused by oil penetration (expansion rate reduced from 1.2% to 0.3%).

[0038] For sludge with a high-hardness impurity (such as sand and gravel) content exceeding 5%, the sludge scraper needs to be equipped with a vibration assistance mechanism. This mechanism consists of an eccentric mass block and a variable-frequency motor, which is installed on the back of the sludge scraper. The vibration frequency is set to be adjustable within the range of 80 - 120 Hz, and the amplitude is 0.1 - 0.3 mm. When the sensor detects that the scraping resistance suddenly increases by more than 50 N, the vibration mode is automatically triggered. At this time, the scraping blade produces a "hammering - peeling" combined effect under the action of micro-amplitude vibration, making the hard particles embedded on the surface of the filter cloth easier to detach. The vibration energy transfer path is optimized through finite element analysis to ensure that more than 90% of the vibration energy is concentrated at the working end of the scraping blade, and the vibration acceleration at the guiding support rod part is suppressed below 2g to avoid affecting the transmission accuracy.

[0039] The electrical control system uses a fuzzy PID algorithm to achieve adaptive adjustment of the sludge scraping parameters. The input variables of the controller include 8-dimensional parameters such as the sludge thickness change rate, scraping resistance gradient, and hydraulic oil temperature rise rate. When it is detected that the rising slope of the scraping resistance exceeds 10 N / m within a 0.5 m stroke, the algorithm automatically reduces the traveling speed and increases the coolant flow rate, and the linkage response time is less than 0.2 seconds. The signal transmission adopts the CAN bus protocol, and the bus terminal matching resistance value is set to 120 Ω ± 1% through debugging with an impedance analyzer to ensure that the signal attenuation rate is lower than 3% within a 30 m cable length. The relay module is built-in with a surge absorption circuit, which consists of a varistor and a gas discharge tube to form a three-level protection, and can withstand the impact of an 8 / 20 μs waveform and 5 kA lightning surge current.

[0040] Example 2

[0041] In this embodiment, the chain drive mechanism can be replaced with a synchronous belt drive system to match different load requirements by adjusting the belt tooth modulus; the polytetrafluoroethylene slider can use an oil-containing bearing alloy material to maintain lubrication performance under higher load conditions; the mechanical detection method of the contact probe can be upgraded to a non-contact photoelectric sensor, and the sludge thickness is judged by the change of the reflected light intensity. These variant solutions adapt to different working conditions and cost control requirements on the premise of keeping the core sludge scraping mechanism unchanged. For example, in a more corrosive working environment, the protective layer of the guiding support rod can be changed to a polyether ether ketone composite material, and its chemical corrosion resistance is more than 50% higher than that of glass fiber reinforced nylon; for the high-viscosity sludge treatment scenario, an auxiliary vibration device can be added to the sludge scraper to reduce the scraping resistance through high-frequency micro-amplitude vibration. This vibration source can come from a hydraulic pulse generator or an electromagnetic vibrator, and the vibration frequency adjustment range covers 50 - 2:

[0042] Example 3

[0043] In this embodiment, the transmission system adopts a direct linear motor drive scheme, transforming the guide support rod into a mover assembly, and embedding a three-phase winding stator within the frame guide rail. The traditional chain drive mechanism is eliminated, increasing the scraper acceleration to 2 m / s², suitable for applications requiring rapid reciprocating motion. The magnetic gap of the linear motor is maintained at 1 mm ± 0.05 mm, and the magnetic field strength distribution is monitored in real time using a Hall sensor array, dynamically adjusting the current phase angle to compensate for thrust fluctuations caused by edge effects. Although this scheme increases energy consumption by 20%, it improves transmission efficiency to 98% and eliminates the need for chain lubrication and maintenance.

[0044] Another innovative structure integrates an electric heating element inside the scraper blade, using a 316L stainless steel tube encapsulating a nickel-chromium alloy wire with a power density of 15W / cm². This allows for surface drying while scraping, further reducing the moisture content of the mud cake by 3-5 percentage points. The heating temperature is controlled in a closed-loop manner by an infrared temperature measurement module, maintaining the surface temperature within the range of 80-100℃. This temperature range promotes moisture evaporation without causing organic matter carbonization.

[0045] Actual production data shows that in a municipal sludge treatment plant with a daily processing capacity of 200 tons, the unit's mean time between failures (MTBF) after 180 days of continuous operation reaches 450 hours, 2.7 times better than traditional scraping systems. Regarding the replacement cycle of key wear parts, the service life of the polyurethane scraper is extended to 600 hours, and the maintenance cycle of the chain drive mechanism reaches 2000 hours, mainly due to three improvements: the gradual thickness design of the scraper uniformizes stress distribution, reducing the maximum equivalent stress from 18MPa to 12MPa; the optimized load distribution of the double-row chain reduces the peak contact stress by 40%; and the guide support rod cooling system stabilizes the operating temperature below 60℃, reducing the creep rate of the nylon protective layer by 65%. Energy consumption analysis shows that the power consumption per ton of sludge treated is 1.8kWh, of which 32% of the energy is used to overcome scraping resistance, 41% is used for the drive system, and 27% is used for auxiliary systems (including cooling, detection, etc.), resulting in energy savings of more than 15% compared to similar equipment. This is mainly attributed to the high efficiency of the chain drive and the suppression of ineffective movements by the closed-loop control system.

[0046] When treating special industrial sludge (such as sludge from dyeing and printing wastewater), a pH adjustment unit needs to be added to the feed end of the equipment. This unit consists of two 500L reagent tanks, storing a 10% concentration of aluminum sulfate solution and polyacrylamide emulsion respectively, which are injected into the mixing reactor at a 1:3 volume ratio via metering pumps. When the online pH sensor detects that the sludge is strongly alkaline (pH > 9), the acid dosing system is automatically activated to adjust the pH to a neutral range of 6.5-7.5. This process must be completed within 30 seconds to avoid the hydrolysis and inactivation of the reagents. After the adjusted sludge has fully reacted in a static mixer, it enters the filter press process. At this point, the cake peelability is improved by 40%, and the energy consumption for sludge scraping is reduced by 22%. The synergistic effect of this chemical pretreatment unit and the mechanical sludge scraping system extends the equipment's ability to treat highly alkaline sludge to conditions below pH 11.5, breaking through the traditional equipment's applicable limit of pH 9.5.

Claims

1. A sludge dewatering device for a chamber-type plate and frame filter press, comprising a frame (1), a filter plate assembly (2), and a pressing mechanism (3), characterized in that: An automatic sludge scraping assembly (5) is provided above the filter plate group (2). The automatic sludge scraping assembly (5) includes a scraper plate (51) that moves horizontally back and forth on the frame guide rail (11), a guide support rod (52) that connects to the scraper plate, and a chain transmission mechanism (53) that is linked to the guide support rod. The bottom surface of the scraper plate (51) is provided with segmented elastic scraper blades (511), and each segment of the scraper blades is hinged by a pin (512) to form an adjustable sludge scraping working surface.

2. The sludge dewatering device according to claim 1, characterized in that: The bottom working surface of the segmented elastic scraper (511) maintains linear contact with the drop tray (4) at an inclination angle of 2-3°.

3. The sludge dewatering device according to claim 1, characterized in that: The chain drive mechanism (53) includes a double-row synchronous chain (531), which meshes with the drive block (521) at the end of the guide support rod (52) via a transition sprocket.

4. The sludge dewatering device according to any one of claims 1-3, characterized in that: An anti-deviation limiting component (54) is provided between the guide support rod (52) and the frame guide rail (11). The anti-deviation limiting component (54) includes a U-shaped slot (541) fixed on the frame and a polytetrafluoroethylene slider (542) embedded in the slot.

5. The sludge dewatering device according to any one of claims 1-3, characterized in that: The top of the scraper (51) is connected to a sludge thickness detection element (55), which consists of a pressure sensing spring and a contact probe (551). The end of the contact probe extends to a position 5-8 mm above the drop tray (4).

6. The sludge dewatering device according to claim 5, characterized in that: The contact probe (551) is connected to the relay module of the electrical control cabinet (6) via a signal line (553). The relay module is equipped with a mud scraping frequency adjustment knob.

7. The sludge dewatering device according to claim 1, characterized in that: The segmented elastic scraper (511) is made of polyurethane board with gradually varying thickness, and the thickness of the board varies continuously in the range of 5-15mm.

8. The sludge dewatering device according to claim 1, characterized in that: The surface of the guide support rod (52) is covered with a glass fiber reinforced nylon protective layer. The guide support rod (52) has a cooling channel inside and is connected to the coolant outlet of the hydraulic station (7) through a hose.

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