Electrofiltration solid-liquid separation device

Abstract

The invention discloses an electrofiltration solid-liquid separation device which comprises a raw water filter tank, a sludge hopper, a water outlet tank, an overflow tank and a clamping plate, the two sides of the lower portion of the raw water filter tank are respectively provided with a water outlet tank, the sludge hopper is arranged at the bottoms of the raw water filter tank and the water outlet tanks and communicated with the raw water filter tank, filter holes are formed in the left side wall and the right side wall of the lower portion of the raw water filter tank, and the filter holes are covered with an electric filter layer formed by combining filter cloth and an electric filter screen and fixed to the filter holes through clamping plates. The electric filter layers on the left and right sides are respectively connected with a cathode and an anode of a power supply; the water outlet tank is communicated with the raw water filter tank through filter holes; the overflow tank is movably arranged at the top in the water outlet tank, a water outlet is formed in one side of the top of the water outlet tank and communicated with the overflow tank, and a sludge outlet is formed in the sludge hopper; the device has the characteristics of strong environmental adaptability and in-situ treatment, and through the synergistic effect of electrodialysis and mechanical filtration, the separation efficiency is improved, the energy consumption is reduced, solid-liquid separation without chemical pollution is realized, and the use of a traditional flocculant is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of multi-stage filtration systems, and particularly relates to an electric filtration solid-liquid separation device. Background Art

[0002] Solid-liquid separation is a ubiquitous unit operation in process industries such as chemical, environmental, pharmaceutical, food, mining, metallurgy, and energy. Resource recycling and solid-liquid separation are key links in a chain of technologies, including tailwater reuse, valuable metal recovery, sludge reduction, and CO2 mineralization and fixation. With the rapid development of large-scale livestock and poultry farming, solid-liquid separation of water-soaked manure is a critical pretreatment step for subsequent resource utilization, such as biogas fermentation and organic fertilizer production. According to statistics, my country generates over 3 billion tons of livestock and poultry manure annually, approximately 60% of which requires solid-liquid separation for volume reduction and harmless treatment. Traditional separation technologies, with their low efficiency, high energy consumption, and frequent secondary pollution, have become a bottleneck restricting the resource utilization of manure. Therefore, the development of efficient, economical, and environmentally friendly solid-liquid separation equipment to separate solid manure from liquid wastewater, thereby achieving waste reduction and resource utilization, is of great significance for protecting the water environment and ecological balance. Summary of the Invention

[0003] In response to the problems existing in the prior art, the present invention provides an electrofiltration solid-liquid separation device, which aims to achieve rapid and efficient in-situ processing, adapt to various working conditions and improve production efficiency.

[0004] The present invention discloses a water-foam feces electrofiltration solid-liquid separation device comprising a raw water filter tank, a sludge hopper, a water outlet box, an overflow trough and a splint; a water outlet box is provided on both sides of the lower portion of the raw water filter tank, the sludge hopper is provided at the bottom of the raw water filter tank and the water outlet box and is connected to the raw water filter tank, filter holes are provided on the left and right side walls of the lower portion of the raw water filter tank, the filter holes are covered with an electrofiltration layer composed of a filter cloth and an electrofiltration mesh and fixed to the filter holes by a splint, the electrofiltration layers on the left and right sides are respectively connected to the anode and cathode of a power supply, and the water outlet box is connected to the raw water filter tank through the filter holes; the overflow trough is movably provided at the top of the water outlet box, a water outlet I is provided on one side of the top of the water outlet box, a water outlet II is provided on the overflow trough, and a sludge outlet is provided on the sludge hopper.

[0005] The sludge hopper is a hollow inverted quadrangular pyramid (inclination ≥ 60°), the inner wall of which is coated with a hydrophobic coating (polytetrafluoroethylene). The sludge hopper is seamlessly connected to the bottom of the raw water filter tank to reduce sludge adhesion; a pneumatic butterfly valve or ball valve is provided on the sludge outlet, which can be combined with a screw conveyor to achieve timed sludge discharge; an ultrasonic vibrator (frequency 28kHz) can be installed in the hopper to regularly vibrate to promote sludge sliding.

[0006] The electric filter mesh in the electric filter layer connected to the anode of the power supply is one of titanium oxide mesh, nickel mesh, copper mesh, and zinc mesh; the electric filter mesh in the electric filter layer connected to the cathode of the power supply is one of stainless steel mesh, chlorine evolution electrode mesh, and hydrogen evolution electrode mesh; a 3-15V DC electric field is applied; the aperture of the electric filter mesh is 2-5mm; the distance between the electric filter mesh connected to the anode of the power supply and the electric filter mesh connected to the cathode of the power supply is 10-30cm; the filter cloth material is polyester fiber, polypropylene, polyester, nylon, polytetrafluoroethylene, cotton cloth, canvas, and the mesh number of the filter cloth is 600-5000 mesh.

[0007] The overflow trough is movably arranged in the inner slot of the water outlet box through a snap buckle, and the height of the overflow trough in the water outlet box is adjustable.

[0008] There is a liquid level difference between the raw water filter tank and the water outlet tank. The liquid level height of the water outlet tank is adjusted by the overflow tank, and then the liquid level difference is regulated to control the power of the raw water passing through the filter screen in the raw water filter tank.

[0009] The device also includes a controller, and the power supply is connected to the electric filter through the controller.

[0010] The water outlet of this device is driven by the liquid level difference. The height of the water outlet tank is 20-50cm lower than the raw water filter tank, forming a natural hydraulic pressure difference (0.2-0.5kPa), driving the liquid through the electric filter layer into the water outlet tank. The overflow tank is located at the top of the water outlet tank. The installation height of the overflow tank can be adjusted. The installation and adjustment method uses conventional structures and methods, such as clips and slots.

[0011] When the above device is used, the soaked feces are placed in the raw water filter tank. There is a liquid level difference between the raw water filter tank and the water outlet tank, which makes the raw water in the raw water filter tank have higher potential energy, generating power to flow toward the water outlet tank, and intercepting solid particles through the mechanical filtration of the electric filter layer; the electric filter is intermittently energized. When it is energized, solid-liquid separation is achieved through the synergistic effect of electrophoresis and mechanical filtration. The charged particles in the raw water migrate to the positive and negative electric filter screens respectively, and collide and aggregate during the migration process. The aggregated sludge produces free sedimentation on the upper part of the raw water filter tank and produces compressed sedimentation in the sludge hopper; the electric filter layer uses water to flush the filter cloth when water enters, and washes off some particles blocked on the filter cloth; the sludge is deposited in the sludge hopper and discharged from the sludge outlet. The filtered water enters the water outlet tank and the overflow tank. When the liquid level exceeds the top of the overflow tank, the upper clear liquid is discharged through the water outlet.

[0012] Advantages and technical effects of the present invention: 1. Electric Field-Hydraulic Coupling Mechanism: A DC pulsed electric field induces electrophoretic migration of particles, combined with mechanical filtration driven by liquid level difference. The system achieves a retention rate of ≥92% for particles larger than 20μm (compared to <60% with conventional technologies), and an effluent SS concentration of ≤200mg / L, meeting emission standards. A gradient filter cloth design: 600-5000 mesh filter cloths are layered for interception, combined with a filter cake effect, to achieve progressive retention from coarse particles to colloids, preventing overload and clogging of a single pore size. Pulsed electric field mode: Intermittent power supply (duty cycle 20-50%) saves 40% energy compared to continuous DC mode, with power consumption ≤1.2kW·h per ton processed, a 76% reduction compared to centrifugal separation (5kW·h). Natural drive by liquid level difference: Utilizing the 20-50cm height difference between the raw water filter tank and the outlet tank, the system generates filtration power, eliminating the need for additional pressure pumps and reducing energy consumption and equipment investment.

[0013] 2. Self-cleaning system: Spray reverse flushing + electric field intermittent power off reverse osmosis, dual mechanism to remove filter cloth blockage. Hydrophobic sludge hopper design: The inner wall of the conical hopper is coated with polytetrafluoroethylene, combined with ultrasonic vibration, the sludge sliding efficiency is improved, and the accumulation of lumps in the hopper is avoided. No chemical additives, environmentally friendly and safe, electric field sterilization function: the anode chlorine reaction generates ClO - , O3, and other oxidizing substances, killing E. coli in manure (removal rate ≥ 99%), reducing the bioburden of subsequent treatment units. No residual chemicals are added: No flocculants are added throughout the entire process. The separated solid phase can be directly composted, and the liquid phase can be used for irrigation or reuse, meeting organic farming standards. Flexible adaptability, strong scalability, and modular structure: Parameters such as filter mesh size, electric field strength, and liquid level difference can be dynamically adjusted according to manure properties (such as solid content and particle size), adapting to different farming scenarios such as pigs, cattle, and chickens. The large-scale processing capacity supports multiple machines in parallel to meet the continuous processing needs of large-scale livestock and poultry farming. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the structure of the device of the present invention; Figure 2 This is a schematic diagram of the raw water filter tank structure; Figure 3 This is a schematic diagram of the sludge hopper structure; Figure 4 Schematic diagram of the splint structure; Figure 5 This is a schematic diagram of the plywood installation structure; Figure 6 Schematic diagram of the overflow tank structure of the present invention; In the figure: 1-raw water filter tank, 2-sludge hopper, 3-water outlet tank, 4-overflow trough, 5-plywood, 6-water outlet I, 7-sludge outlet, 8-filter hole, 9-water outlet II. DETAILED DESCRIPTION

[0015] The present invention is further illustrated by the following examples, but these examples do not limit the scope of protection of the present invention. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercial reagents or reagents prepared according to conventional methods unless otherwise specified. Example 1: Figure 1 As shown, the water-foam feces electrofiltration solid-liquid separation device includes a raw water filter tank 1, a sludge hopper 2, a water outlet box 3, an overflow tank 4, and a splint 5; the raw water filter tank 1 is a polypropylene tank body, and a water outlet box 3 is provided on both sides of the lower part of the raw water filter tank 1; the sludge hopper 2 is provided at the bottom of the raw water filter tank 1 and the water outlet box 3 and is connected to the raw water filter tank 1; the sludge hopper is a hollow inverted quadrangular pyramid, and its inner wall is coated with a polytetrafluoroethylene hydrophobic coating; three filter holes are opened on the left and right side walls of the lower part of the raw water filter tank 1, and the filter holes are covered with a filter cloth (800 mesh) and an electric filter screen composite. The electric filter layer is fixed to the filter hole by a clamping plate 5. The electric filter layers on the left and right sides are respectively connected to the anode and cathode of the power supply. The electric filter mesh in the electric filter layer connected to the anode of the power supply is a titanium oxide mesh, and the electric filter mesh in the electric filter layer connected to the cathode of the power supply is a stainless steel mesh. The electric filter mesh pore size is 2-3mm, and the distance between the electric filter mesh connected to the anode of the power supply and the electric filter mesh connected to the cathode of the power supply is 30cm. The water outlet box 3 is connected to the raw water filter tank 1 through the filter hole 8. The overflow tank 4 is movably arranged at the top of the water outlet box 3. A water outlet I 6 is opened on one side of the top of the water outlet box 3. A water outlet II 9 is opened on the overflow tank 4. A sludge outlet 7 is provided on the sludge hopper 2. When the above device is used, soak the feces in water for 2m 3 Add to the raw water filter tank 1 until the mixture occupies 85% of the raw water filter tank, turn on the pulse DC power supply, and set the initial parameters to 8V voltage, 50Hz frequency, and 30% duty cycle (power-on time 0.3 seconds / cycle). Observe the ammeter reading to ensure that the electric field working current is stable in the range of 10-20A. Power on for 5 minutes every 2 hours. The overflow tank is 40cm away from the water level line of the raw water tank. After the water level of the outlet tank reaches the water outlet of the overflow tank, the filtered supernatant begins to be discharged. Stop feeding after running for 24 hours. After the liquid level of the raw water filter tank drops to 10%, turn off the electric field system, then empty the residual sludge in the sludge hopper, rinse the electric filter layer and pipeline with clean water for 30 minutes, and take the supernatant discharged from the outlet tank during operation for testing.

[0016] After testing, the suspended solids (SS) before treatment was 8451 mg / L and 184 mg / L after treatment, with a removal rate of ≥97%, which meets the requirements of the "Livestock and Poultry Breeding Pollutant Emission Standard" (GB 18596-2001): SS≤400 mg / L.

[0017] Example 2: The device structure of this example is the same as that of Example 1, except that a 600-mesh filter cloth is used, the electrode spacing is 20 cm, and a 10V DC electric field is applied. A nickel mesh electrode is used as the anode, and a stainless steel filter mesh is used as the cathode. Approximately 3 m³ of pig manure is treated, and the liquid level reaches 90% of the filter plate height. The electric field parameters are set to 10V, 60Hz, and a 40% duty cycle (power-on time 0.4 seconds / cycle). Power is applied for 10 minutes every 3 hours, and the operation is continuous for 48 hours. Treatment results: SS was 10,235 mg / L before treatment and 215 mg / L after treatment, with a removal rate of ≥97.9%. Meanwhile, the E. coli removal rate reached 99.5%.

[0018] Example 3: The structure of the device in this example is the same as that in Example 1, except that a 1000 mesh filter cloth is used, the electrode spacing is 25 cm, a 12V DC electric field is applied, a copper mesh electrode is used as the anode, and a stainless steel filter mesh is used as the cathode. The device can process about 2.5m of cow dung and water-soaked dung. 3 , the liquid level reached 80% of the filter plate height. The electric field parameters were set to 12V, 70Hz, and a 35% duty cycle (0.35 seconds per cycle). The power was applied for 15 minutes every four hours for a total of 72 hours of continuous operation.

[0019] Treatment Results: SS concentrations were 12,450 mg / L before treatment and 198 mg / L after treatment, with a removal rate of ≥98.4%. The effluent SS concentration met the requirements of the "Livestock and Poultry Farming Pollutant Emission Standards."

[0020] Example 4: Comparison of treatment effects of different liquid level differences The structure of the device in this embodiment is the same as that in Example 1, except that an 800-mesh filter cloth is used, the electrode spacing is 20 cm, a 10V DC electric field is applied, and the raw water is pig manure soaked in feces. The SS before treatment is measured to be 8451 mg / L. The overflow tank 4 is movably arranged in the inner slot of the water outlet tank by a snap-fit, and the height of the overflow tank in the water outlet tank is adjustable; The liquid level difference between the raw water filter tank and the outlet tank is set to 20cm, 30cm, 40cm and 50cm respectively. Other conditions remain unchanged. Water is continuously added to the raw water filter tank. The position of the overflow tank outlet Ⅱ9 and the distance between it and the water level of the raw water filter tank 1 are adjusted to 20cm, 30cm, 40cm and 50cm. When the water level of the outlet tank 3 is higher than the overflow tank outlet Ⅱ9, the upper clear liquid is discharged through the outlet Ⅰ6, and the water inlet size of the raw water filter tank is adjusted by the water output to maintain the liquid level difference unchanged.

[0021] Processing results: Liquid level difference 20cm: SS 8451 mg / L before treatment, 205 mg / L after treatment Liquid level difference 30cm: SS 8451 mg / L before treatment, 195 mg / L after treatment Liquid level difference 40cm: SS 8451 mg / L before treatment, 188 mg / L after treatment Liquid level difference 50cm: SS 8451 mg / L before treatment, 184 mg / L after treatment As the liquid level difference increases, the treatment effect improves slightly, but when the liquid level difference exceeds 40cm, the improvement effect is not obvious. Considering energy consumption and treatment effect, it is recommended to set the liquid level difference between 40-50cm.

[0022] These examples demonstrate the application effects of the electrofiltration solid-liquid separation device under different conditions, and verify its good adaptability and efficient treatment capabilities for different types of manure and sewage.

Claims

1. An electrofiltration solid-liquid separation device, characterized in that: The invention comprises a raw water filter tank (1), a sludge hopper (2), a water outlet box (3), an overflow trough (4), and a splint (5); a water outlet box (3) is respectively provided on both sides of the lower part of the raw water filter tank (1); the sludge hopper (2) is provided at the bottom of the raw water filter tank (1) and the water outlet box (3) and is communicated with the raw water filter tank (1); filter holes are provided on the left and right side walls of the lower part of the raw water filter tank (1); the filter holes are covered with an electric filter layer composed of one or more filter cloths and an electric filter mesh and fixed to the filter holes through the splint (5); the electric filter layers on the left and right sides are respectively connected to the positive and negative poles of the power supply; the water outlet box (3) is communicated with the raw water filter tank (1) through the filter holes; the overflow trough (4) is movably provided at the top of the water outlet box (3); a water outlet I is provided on one side of the top of the water outlet box (3); a water outlet II is provided on the overflow trough (4); and a sludge outlet is provided on the sludge hopper (2).

2. The electrofiltration solid-liquid separation device according to claim 1, characterized in that: The sludge hopper is a hollow inverted quadrangular cone, and its inner wall is coated with a hydrophobic coating.

3. The electrofiltration solid-liquid separation device according to claim 1, characterized in that: The electric filter mesh in the electric filter layer connected to the anode of the power supply is one of titanium oxide mesh, nickel mesh, copper mesh, and zinc mesh; the electric filter mesh in the electric filter layer connected to the cathode of the power supply is one of stainless steel mesh, chlorine evolution electrode mesh, and hydrogen evolution electrode mesh; a 3-15V DC electric field is applied; and the distance between the electric filter mesh connected to the anode of the power supply and the electric filter mesh connected to the cathode of the power supply is 10-30cm.

4. The electrofiltration solid-liquid separation device according to claim 1, characterized in that: The overflow trough (4) is arranged in the inner slot of the water outlet box through a snap-fit ​​mechanism, and the height of the overflow trough in the water outlet box is adjustable.

5. The electrofiltration solid-liquid separation device according to claim 4, characterized in that: There is a liquid level difference between the raw water filter tank and the water outlet tank. The liquid level height of the water outlet tank is adjusted by the overflow tank, and then the liquid level difference is regulated to control the power of the raw water passing through the filter screen in the raw water filter tank.

6. The electrofiltration solid-liquid separation device according to claim 1, characterized in that: An acoustic vibrator is provided in the sludge hopper.

7. The electrofiltration solid-liquid separation device according to claim 1, characterized in that: The utility model also comprises a controller, and the power supply is connected with the electric filter through the controller.

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