A wastewater treatment device

Abstract

This invention discloses a wastewater treatment device in the field of wastewater treatment technology, including a treatment tank. The treatment tank is divided into a mixing tank, a flotation tank, and an oil storage tank by first and second partitions. An oil filter assembly is installed on the second partition. This assembly includes an oil filter tank and sludge inlet and outlet channels connecting its two sides. The bottom of the oil tank is evenly distributed with oil leakage holes, and two extrusion columns extending in opposite directions and vertically are installed inside. The cross-section of the extrusion column consists of a superior arc, a inferior arc, and transition arcs at both ends. The inferior arc is longer than the superior arc, and the transition arcs are chamfered at the connection with the inferior arc, with their concave direction opposite to that of the superior arc. The two columns are arranged with the inferior arc surface facing the superior arc surface, and the inferior arc surface is tightly fitted to the inner wall of the oil filter tank. The wastewater treatment device of this application can effectively achieve the separate collection of suspended particulate matter and oil in the scum.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and specifically relates to a wastewater treatment device. Background Technology

[0002] Oily wastewater is widely generated in numerous industries, including petroleum extraction, refining, chemical processing, machinery manufacturing, and food processing. If discharged directly without effective treatment, this wastewater will form an oil film on the water surface, hindering oxygen dissolution and causing aquatic life to die from oxygen deprivation, severely disrupting the ecological balance. Simultaneously, oily wastewater also pollutes soil and groundwater, affecting crop growth and endangering human health. Therefore, properly treating oily wastewater to achieve compliant discharge or reuse is of significant environmental importance and a practical necessity.

[0003] Dissolved air flotation (DAF) technology is a commonly used method for treating oily wastewater and has been widely applied in the industrial field. Its basic principle is to dissolve a large amount of air in water under a certain pressure to form dissolved air water. When the dissolved air water is suddenly depressurized and enters the wastewater treatment tank, the supersaturated air in the water is released in the form of tiny bubbles. These tiny bubbles adhere to pollutants such as oil droplets and suspended particles in the wastewater, forming a flotation mass with a specific gravity less than water. Under the action of buoyancy, the flotation mass floats to the surface, thus achieving the separation of pollutants from water.

[0004] However, in practical applications, when using dissolved air flotation (DAF) technology to treat oily wastewater, suspended particles and oil in the scum are pushed together into the sludge tank. This is because, during the flotation stage, although most oil droplets are carried to the surface by the air bubbles, some oil droplets adhere to the surface of the suspended particles and float to the surface along with them, forming scum. Because existing FAF equipment and processes lack an effective separation mechanism for suspended particles and oil during the scum stage, the suspended particles and oil remain mixed after the scum is collected in the sludge tank. This mixing not only increases the difficulty and cost of subsequent suspended particle treatment—for example, during dewatering, oil can affect the dewatering effect and reduce the operating efficiency of the dewatering equipment—but also the oil in the mixed suspended particles may leak again during subsequent treatment, causing secondary pollution. Summary of the Invention

[0005] The present invention aims to provide a wastewater treatment device to achieve separate collection of suspended particulate matter and oil in scum.

[0006] This solution provides a wastewater treatment device, including a treatment tank. The treatment tank is divided into a mixing tank, a flotation tank, and an oil storage tank by a first partition plate and a second partition plate. A sealing plate is fixedly connected to the second partition plate, sealing the top of the mixing tank and the flotation tank. The sealing plate is located directly above the first partition plate. An oil filter assembly is connected to the second partition plate. The oil filter assembly includes an oil filter box and connected sludge inlet and sludge outlet channels. The sludge inlet and sludge outlet channels are respectively connected to opposite sides of the oil filter box. Oil leakage holes are evenly distributed at the bottom of the oil filter box. Two oppositely rotating rods are rotatably connected inside the oil filter box. The extrusion column has its length direction aligned with the height direction of the oil filter box. The cross-sectional profile of the extrusion column consists of a major arc, a minor arc, and two transition arcs. The two ends of the transition arc smoothly connect the ends of the major and minor arcs, respectively. The minor arc is longer than the major arc. A chamfer is provided at the connection between the transition arc and the minor arc. The length of the minor arc is greater than the length of the major arc. The concave direction of the transition arc and the minor arc is opposite to that of the major arc. The minor arc surface of one extrusion column is directly opposite to the major arc surface of another extrusion column. The minor arc surface of the extrusion column is in contact with the inner wall of the oil filter box, and the lower surface of the extrusion column is in contact with the inner bottom of the oil filter box.

[0007] The working principle of this scheme is as follows: When oily wastewater enters the mixing tank, the dissolved air supplied by the dissolved air tank is fully mixed with the wastewater, and then it enters the flotation tank. In the flotation tank, microbubbles combine with oil droplets and suspended particles to form scum. After the scum enters the oil filter tank through the scum inlet channel, two extrusion columns rotating in opposite directions begin to rotate synchronously in opposite directions. The inferior arc surface of the extrusion column adheres to the inner wall of the oil filter tank to form an extrusion zone. As it rotates, the scum is gradually compressed by the transition arc of the extrusion column, and the oil is separated from the suspended particles under pressure and flows into the oil storage tank through the oil leakage hole. The suspended particles, after being deoiled, lose their oil viscosity and slide into the scum storage tank along the inclined surface of the scum discharge channel under the push of the extrusion column, thus achieving the physical separation of oil and suspended particles.

[0008] The beneficial effects of this solution are as follows: This solution utilizes the rotational compression action of the extrusion columns to forcibly separate oil and suspended particulate matter from the scum, significantly improving separation efficiency. Furthermore, the integrated design of the oil filter assembly and treatment tank reduces the floor space required, making it suitable for retrofitting existing air flotation systems. Additionally, during the scum extrusion process, the two extrusion columns initially utilize their inferior arc surfaces to collect a large amount of scum, then gradually reduce the distance between their extrusion surfaces, achieving better scum compression.

[0009] Furthermore, the distance between the inferior arc surface of the extrusion column and the superior arc surface of the opposite extrusion column is 0–0.5 mm, preferably 0.001–0.5 mm. This distance ensures that the two extrusion columns form a highly concentric extrusion surface with the scum during rotation. As the scum passes through this narrow gap, it experiences more concentrated and powerful extrusion force, causing oil droplets in the scum to be squeezed out more fully. This significantly improves the separation efficiency of oil and suspended particulate matter, resulting in purer oil collected in the oil storage tank and lower oil content in the suspended particulate matter in the slag storage tank.

[0010] Furthermore, two rotating shafts are rotatably connected inside the oil filter tank, and driven gears are fixedly connected to both shafts. The two driven gears mesh with each other. A power mechanism that drives one of the driven gears to rotate is provided on the outer wall of the treatment tank. The extrusion column has a fixing hole, which is concentric with the major and minor arcs. The two extrusion columns are fixedly connected to the two rotating shafts through the fixing holes. The meshing of the driven gears ensures that the two extrusion columns can rotate stably and synchronously in opposite directions, ensuring the continuity and stability of the scum extrusion action and improving the separation effect. The fixed connection of the extrusion column to the rotating shaft through the fixing hole facilitates the installation and disassembly of the extrusion column, which is beneficial for the daily maintenance and repair of the equipment.

[0011] Furthermore, the power mechanism includes a motor and a drive gear mounted on the motor's output shaft. The drive gear is connected to a gear transmission assembly, where one transmission gear meshes with one driven gear. The motor transmits power through the meshing of the drive gear, the transmission gear assembly, and the driven gear, resulting in high transmission efficiency and a stable power supply for the rotation of the extrusion column.

[0012] Furthermore, the outer wall of the extrusion column is provided with an oil inlet hole, and the extrusion column has a cavity communicating with the oil inlet hole. The bottom of the cavity is connected to an oil leakage hole. The oil inlet hole helps the oil to quickly enter the oil storage tank from the oil inlet hole, the cavity, and the oil leakage hole after the scum is extruded by the extrusion column.

[0013] Furthermore, the mixing tank is connected to a dissolved air tank. The dissolved air tank provides dissolved air water to the mixing tank, ensuring the conditions required for dissolved air flotation technology, promoting the full adhesion of pollutants and air bubbles in the wastewater, and improving the overall wastewater treatment effect.

[0014] Furthermore, the treatment tank is also equipped with a third partition plate, with a second partition plate located between the first and third partition plates. The third partition plate and the wall of the treatment tank form a slag storage tank, and the discharge end of the slag discharge channel is connected to the slag storage tank. A dedicated slag storage tank is provided to collect the suspended particulate matter after it has been separated by the oil filtration assembly, facilitating subsequent centralized treatment of the suspended particulate matter.

[0015] Furthermore, the driven gear is located below the oil filter tank. Positioning the driven gear below the oil filter tank prevents scum inside the tank from interfering with gear meshing, ensuring smooth gear transmission and extending equipment lifespan. Additionally, the oil discharged through the filter tank after being squeezed by the scum provides lubrication and cooling to the driven gear.

[0016] Furthermore, the bottom of the slag discharge channel is a downward sloping surface. This facilitates the smooth passage of suspended particles through the slag discharge channel under the action of gravity, reduces the residue of suspended particles in the channel, and prevents blockage of the slag discharge channel.

[0017] Furthermore, the dissolved air flotation (DAF) tank is connected to a water collector, and a valve is installed at the connection between the water collector and the DAF tank. The water collector can collect water that meets the discharge standards after DAF treatment, and the water flow is controlled by the valve to facilitate subsequent treatment or discharge of the compliant water.

[0018] Furthermore, the wall of the flotation tank is equipped with a level sensor for detecting the water level. The valve is an electrically controlled valve, and the electrically controlled valve, level sensor, and motor are connected to the same controller. The controller is used to control the on / off state and speed of the motor, and also to receive information from the level sensor and control the on / off state and flow rate of the electrically controlled valve. The level sensor monitors the water level in the flotation tank in real time and feeds the information back to the controller. The controller automatically adjusts the motor speed and the flow rate of the water effluent from the flotation tank according to the water level, realizing the automated operation of the equipment.

[0019] Furthermore, a wear-resistant rubber sleeve is fitted onto the extrusion column. This wear-resistant rubber sleeve effectively buffers the friction between the extrusion column and the inner wall of the oil filter tank, as well as the scum, reducing the wear rate of the extrusion column body and extending its service life. The rubber sleeve also has a certain degree of elasticity, allowing it to better conform to the inner wall of the oil filter tank and the scum during the extrusion process, filling the tiny gaps between the extrusion column and the inner wall of the oil filter tank, resulting in more even force distribution on the scum, thereby improving the separation efficiency of oil and sludge and ensuring the effectiveness of scum separation. Attached Figure Description

[0020] Figure 1 This is a partial sectional view of the front view of a wastewater treatment device according to Embodiment 1 of the present invention;

[0021] Figure 2 for Figure 1 Top view of the middle oil filter assembly;

[0022] Figure 3 for Figure 2 Schematic diagram of the structure of the second extrusion column;

[0023] Figure 4 This is a schematic diagram of the structure of the oil filter assembly in a wastewater treatment device according to Embodiment 2 of the present invention. Detailed Implementation

[0024] The following detailed description illustrates the specific implementation methods:

[0025] The reference numerals in the accompanying drawings include: dissolved air tank 1, treatment tank 2, mixing tank 3, first partition plate 4, flotation tank 5, liquid level sensor 6, second partition plate 7, slag inlet channel 8, oil filter box 9, box cover 10, extrusion column 11, slag discharge channel 12, slag storage tank 13, third partition plate 14, oil leakage hole 15, support column 16, driven gear 17, oil storage tank 18, wear-resistant rubber sleeve 19, and sealing plate 20.

[0026] Example 1 is basically as shown in the appendix. Figures 1-3 As shown: A wastewater treatment device includes a treatment tank 2, a power mechanism and a dissolved air tank 1. The power mechanism includes a protective box and a motor and a transmission gear set located inside the protective box. A drive gear is installed on the output shaft of the motor. The transmission gear set includes multiple transmission gears. The dissolved air tank 1 and the protective box are both installed on the outer wall of the treatment tank 2.

[0027] The treatment tank 2 is sequentially divided into a first partition plate 4, a second partition plate 7, and a third partition plate 14, which divide it into a mixing tank 3, an air flotation tank 5, an oil storage tank 18, and a slag storage tank 13. A sealing plate 20 is fixedly connected to the second partition plate 7 to seal the top of the mixing tank 3 and the air flotation tank 5. The sealing plate 20 is located directly above the first partition plate 4. The dissolved air tank 1 is connected to the mixing tank 3 through a pipe. An oil filter assembly is installed between the second partition plate 7 and the third partition plate 14. The oil filter assembly includes an oil filter tank 9 and a slag inlet channel 8 and a slag outlet channel 12 connected thereto. The slag inlet channel 8 and the slag outlet channel 12 are respectively connected to opposite sides of the oil filter tank 9. The ends of the slag inlet channel 8 and the slag outlet channel 12 away from the oil filter tank 9 are respectively fixed on the second partition plate 7 and the third partition plate 14. The ends of the slag inlet channel 8 and the slag outlet channel 12 away from the oil filter tank 9 are respectively connected to the flotation tank 5 and the slag storage tank 13. The bottom of the slag outlet channel 12 is a downward sloping surface. The flotation tank 5 is connected to a water collector. An electric control valve is installed at the connection between the water collector and the flotation tank 5. A liquid level sensor 6 for detecting the water level is installed on the wall of the flotation tank 5. The electric control valve, the liquid level sensor 6 and the motor are connected to the same controller. The controller is used to control the on / off state and speed of the motor, and also to receive information from the liquid level sensor 6 and control the on / off state and flow rate of the electric control valve.

[0028] The oil storage tank 18 is detachably connected to a support column 16. The top of the support column 16 is rotatably connected to two rotating shafts. The two rotating shafts pass through the bottom of the oil filter box 9 and extend upward. Each of the two rotating shafts is equipped with a driven gear 17. The driven gears 17 are located below the oil filter box 9 and mesh with each other. One of the driven gears 17 meshes with one of the transmission gears.

[0029] The top of the oil filter box 9 is fastened with a box cover 10, and the bottom of the oil filter box 9 is evenly distributed with oil leakage holes 15; extrusion columns 11 are fixedly connected to both rotating shafts. Specifically, the length direction of the extrusion column 11 is consistent with the height direction of the oil filter box 9. The cross-sectional profile of the extrusion column 11 consists of a major arc, a minor arc, and two transition arcs. The two ends of the transition arc smoothly connect the ends of the major arc and the minor arc, respectively. The minor arc is longer than the major arc. A chamfer is provided at the connection between the transition arc and the minor arc. The length of the minor arc is greater than the length of the major arc. The concave direction of the transition arc and the minor arc is the same as that of the major arc. Conversely, the minor arc surface of one extrusion column 11 is directly opposite the major arc surface of another extrusion column 11. The distance between the minor arc surface of the extrusion column 11 and the major arc surface of the extrusion column 11 it is directly opposite is 0.001 to 0.5 mm. The minor arc surface of the extrusion column 11 is in contact with the inner wall of the oil filter box 9, and the lower surface of the extrusion column 11 is in contact with the inner bottom of the oil filter box 9. The extrusion column 11 is provided with a fixing hole, which is concentric with the major and minor arcs. The two extrusion columns 11 are fixedly connected to the two rotating shafts respectively through the fixing hole.

[0030] The specific implementation process is as follows: Oily wastewater is transported through pipelines to the mixing tank 3 of treatment tank 2. Simultaneously, the dissolved air tank 1 begins operation, dissolving a large amount of air into the water under a certain pressure to form dissolved air water, which is then injected into the mixing tank 3 through connecting pipelines. The oily wastewater and dissolved air water are thoroughly mixed in the mixing tank 3, creating conditions for subsequent air flotation treatment.

[0031] The mixed water flows from mixing tank 3 through the first partition plate 4 into flotation tank 5. In flotation tank 5, the dissolved air water is suddenly depressurized, and the supersaturated air is released in the form of tiny bubbles. These tiny bubbles quickly adhere to pollutants such as oil droplets and suspended particles in the oily wastewater, forming flotation bodies with a specific gravity less than water. Under the action of buoyancy, the flotation bodies float to the surface of flotation tank 5, forming scum.

[0032] As the flotation process continues, the scum on the water surface is propelled by the water flow and enters the oil filter tank 9 of the oil filter assembly through the scum inlet channel 8. The motor inside the protective box is started, and the motor output shaft drives the drive gear to rotate. The drive gear, through the transmission gear set, drives one of the driven gears 17 to rotate. Because the two driven gears 17 mesh with each other, the two shafts drive the two extrusion columns 11 to rotate synchronously in opposite directions. Once the scum enters the oil filter tank 9, the two extrusion columns 11 begin to work. First, the inferior arc surfaces of the two extrusion columns 11 collect a large amount of scum. As the extrusion columns 11 rotate, the distance between the extrusion surfaces of the two extrusion columns 11 gradually decreases. Under the extrusion of the transition arc and inferior arc of the two extrusion columns 11, the oil is squeezed out from the suspended particles. The outer wall of the extrusion column 11 has an oil inlet hole. The squeezed oil directly enters the oil storage tank 18 through the drain hole or enters the cavity inside the extrusion column 11 through the oil inlet hole, and then flows from the bottom of the cavity into the oil storage tank 18 through the drain hole 15 at the bottom of the oil filter tank 9.

[0033] After oil removal, the suspended particles, having lost their oil viscosity, slide down the inclined surface at the bottom of the slag discharge channel 12 into the slag storage tank 13 under the push of the extrusion column 11. The inclined surface design at the bottom of the slag discharge channel 12 allows the suspended particles to slide smoothly under the action of gravity, reducing residue in the channel and preventing blockage.

[0034] After the treated water in the flotation tank 5 meets the discharge standards, the controller opens the electrically controlled valve based on the real-time water level information monitored by the level sensor 6. The treated water is collected through a water collector for further treatment or discharge. Simultaneously, the controller automatically adjusts the speed of the electrically controlled valve and the motor based on the water level feedback from the level sensor 6 to prevent water from entering the scum inlet channel 8 due to excessively high water levels. It also judges the rate of scum formation by the rate of water level rise and adjusts the motor speed accordingly. When the water level rises rapidly, the motor speed is appropriately increased to accelerate scum treatment; when the water level rises slowly, the motor speed is reduced to save energy.

[0035] The only difference between Example 2 and Example 1 is that a wear-resistant rubber sleeve 19 is fitted onto the extrusion column 11, as shown in the attached figure. Figure 4 As shown.

[0036] The only difference between Example 3 and Example 1 is that: the outer wall of the extrusion column 11 is provided with an oil inlet hole, the extrusion column 11 is provided with a cavity communicating with the oil inlet hole, and the bottom of the cavity is communicating with the oil leakage hole 15.

[0037] The only difference between Example 4 and Example 2 is that: the outer wall of the extrusion column 11 is provided with an oil inlet hole, the extrusion column 11 is provided with a cavity communicating with the oil inlet hole, the bottom of the cavity is communicating with the oil leakage hole 15, and the wear-resistant rubber sleeve 19 is also provided with oil inlets.

[0038] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A wastewater treatment device, comprising a treatment tank, the treatment tank being provided with a first partition plate and a second partition plate dividing it into a mixing tank, a flotation tank and an oil storage tank; The feature is that a sealing plate that seals the top of the mixing tank and the flotation tank is fixedly connected to the second partition plate, and the sealing plate is located directly above the first partition plate; An oil filter assembly is connected to the second partition plate. The oil filter assembly includes an oil filter box and slag inlet and slag outlet channels connected to it. The slag inlet and slag outlet channels are respectively connected to opposite sides of the oil filter box. Oil leakage holes are evenly distributed at the bottom of the oil filter box. Two extrusion columns rotating in opposite directions are rotatably connected inside the oil filter box. The length direction of the extrusion columns is consistent with the height direction of the oil filter box. The cross-sectional profile of the extrusion column consists of a major arc, a minor arc, and two transition arcs. The two ends of the transition arc smoothly connect to the ends of the major and minor arcs, respectively. A chamfer is provided at the connection between the transition arc and the minor arc. The length of the minor arc is greater than the length of the major arc, and the concave direction of the transition arc and the minor arc is opposite to that of the major arc. The minor arc of one extrusion column... The surface of the extrusion column is directly opposite the surface of the superior arc of another extrusion column, the surface of the inferior arc of the extrusion column is in contact with the inner wall of the oil filter box, and the lower surface of the extrusion column is in contact with the inner bottom of the oil filter box; the distance between the surface of the inferior arc of the extrusion column and the surface of the superior arc of the extrusion column directly opposite it is 0 to 0.5 mm; two rotating shafts are rotatably connected inside the oil filter box, and driven gears are fixedly connected to both rotating shafts. The two driven gears mesh with each other. A power mechanism that drives one of the driven gears to rotate is provided on the outer wall of the treatment tank. The extrusion column is provided with a fixing hole, which is concentric with the superior and inferior arcs. The two extrusion columns are fixedly connected to the two rotating shafts respectively through the fixing hole.

2. The wastewater treatment device according to claim 1, characterized in that: The power mechanism includes a motor and a drive gear mounted on the output shaft of the motor. The drive gear is connected to a gear transmission assembly, and one of the transmission gears in the gear transmission assembly meshes with one of the driven gears.

3. The wastewater treatment device according to claim 2, characterized in that: The outer wall of the extrusion column is provided with an oil inlet hole, and the extrusion column is provided with a cavity communicating with the oil inlet hole. The bottom of the cavity is connected to the oil leakage hole.

4. The wastewater treatment device according to claim 3, characterized in that: The treatment tank is also equipped with a third partition plate. The second partition plate is located between the first partition plate and the third partition plate. The third partition plate and the wall of the treatment tank form a slag storage tank. The discharge end of the slag discharge channel is connected to the slag storage tank.

5. The wastewater treatment device according to claim 4, characterized in that: The driven gear is located below the oil filter tank.

6. The wastewater treatment device according to claim 5, characterized in that: The bottom of the slag discharge channel is a downward sloping surface. The flotation tank is connected to a water collector, and a valve is provided at the connection between the water collector and the flotation tank.

7. A wastewater treatment device according to claim 6, characterized in that: The wall of the flotation tank is equipped with a level sensor for detecting the water level. The valve is an electrically controlled valve. The electrically controlled valve, the level sensor and the motor are connected to the same controller. The controller is used to control the on / off state and speed of the motor, and also to receive information from the level sensor and control the on / off state and flow rate of the electrically controlled valve.

8. A wastewater treatment device according to claim 7, characterized in that: The extrusion column is fitted with a wear-resistant rubber sleeve.

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