Wastewater treatment device

Abstract

The invention discloses a wastewater treatment device in the technical field of sewage treatment, which comprises a treatment tank, the treatment tank is divided into a mixing tank, an air floatation tank and an oil storage tank by a first partition plate and a second partition plate, and the second partition plate is provided with an oil filtering assembly. The slag inlet channel and the slag outlet channel are communicated with the two sides of the oil filter tank, oil leakage holes are evenly distributed in the bottom of the oil filter tank, and two extrusion columns opposite in rotating direction and extending in the height direction are arranged in the oil filter tank. The cross section of the extrusion column is composed of a major arc, an inferior arc and transition arcs at the two ends, the inferior arc is longer than the major arc, the joints of the transition arcs and the inferior arc are chamfered, and the indent direction is opposite to that of the major arc. The inferior arc surfaces and the superior arc surfaces of the two columns are oppositely arranged, and the inferior arc surfaces are tightly attached to the inner wall of the oil filter tank. The wastewater treatment device provided by the invention can effectively realize separate collection of suspended particulate matters and oil in scum.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and particularly relates to a wastewater treatment device. Background Art

[0002] Oil-containing wastewater is widely generated in many industries such as oil exploration, oil refining, chemical engineering, machinery manufacturing, and food processing. If such wastewater is directly discharged without effective treatment, an oil film will form on the water surface, hindering the dissolution of oxygen, causing aquatic organisms to die due to lack of oxygen, and seriously disrupting the ecological balance. At the same time, oil-containing wastewater will also pollute soil, groundwater, etc., affect the growth of crops, and endanger human health. Therefore, proper treatment of oil-containing wastewater to achieve up-to-standard discharge or reuse has important environmental protection significance and practical needs.

[0003] As a commonly used method for treating oil-containing wastewater, the dissolved air flotation technology has been widely used in the industrial field. Its basic principle is that under a certain pressure, a large amount of air is dissolved in water to form dissolved air water. When the dissolved air water suddenly decompresses 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 body with a specific gravity less than that of water, which floats to the water surface under the action of buoyancy, thereby realizing the separation of pollutants from water.

[0004] However, in the actual application process, when using the dissolved air flotation technology to treat oil-containing wastewater, the suspended particulate matter and oil in the floating sludge will be pushed into the sludge tank together. This is because in the flotation stage, although most of the oil droplets are carried by the bubbles and float upward, some oil droplets will adsorb on the surface of the suspended particulate matter particles and float to the water surface together with the suspended particulate matter to form floating sludge. Due to the lack of an effective separation mechanism for suspended particulate matter and oil in the floating sludge stage in the existing flotation equipment and technological processes, after the floating sludge is collected in the sludge tank, the suspended particulate matter and oil are in a mixed state. This mixed state not only increases the difficulty and cost of subsequent treatment of suspended particulate matter. For example, during the dehydration process of suspended particulate matter, the oil content will affect the dehydration effect and reduce the operating efficiency of the dehydration equipment; moreover, the oil content in the mixed suspended particulate matter may leak again during subsequent disposal, 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 the floating sludge.

[0006] A wastewater treatment device in this solution includes a treatment tank, which is provided with a first partition board and a second partition board that divide it into a mixing tank, a flotation tank, and an oil storage tank. A sealing board that seals the tops of the mixing tank and the flotation tank is fixedly connected to the second partition board, and the sealing board is directly above the first partition board. A filter oil assembly is connected to the second partition board. The filter oil assembly includes a filter oil tank and a slag inlet channel and a slag discharge channel connected to it. The slag inlet channel and the slag discharge channel are respectively communicated with the opposite sides of the filter oil tank, and oil leakage holes are evenly distributed at the bottom of the filter oil tank. Two extrusion columns rotating in opposite directions are rotatably connected in the filter oil tank. The length direction of the extrusion column is consistent with the height direction of the filter oil tank. 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 are respectively smoothly connected to the ends of the major arc and the minor arc. 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 that of the major arc. The concave directions of the transition arc and the minor arc are opposite to that of the major arc. The minor arc surface of one extrusion column faces the major arc surface of the other extrusion column. The minor arc surface of the extrusion column fits against the inner wall of the filter oil tank, and the lower surface of the extrusion column fits against the inner bottom of the filter oil tank.

[0007] The working principle of this solution: When the oily wastewater enters the mixing tank, the dissolved air water provided by the dissolved air tank is fully mixed with the wastewater and then enters the flotation tank. In the flotation tank, tiny bubbles combine with oil droplets and suspended particles to form floating slag. After the floating slag enters the filter oil tank through the slag inlet channel, the two extrusion columns rotating in opposite directions start to rotate synchronously in the opposite direction. The minor arc surface of the extrusion column fits against the inner wall of the filter oil tank to form an extrusion area. As it rotates, the floating slag is gradually compressed by the transition arc of the extrusion column. The oil is separated from the suspended particulate matter under pressure and flows into the oil storage tank through the oil leakage holes. The suspended particulate matter after oil removal loses its oil viscosity and slides along the inclined surface of the slag discharge channel under the push of the extrusion column into the slag storage tank, realizing the physical separation of oil and suspended particles.

[0008] The beneficial effects of this solution: Through the rotational compression of the extrusion column, the oil and suspended particulate matter in the floating slag are forcibly separated, and the separation efficiency is significantly improved. Moreover, the filter oil assembly and the treatment tank are integrally designed, reducing the floor area and being suitable for transforming the existing flotation system. In addition, during the process of the extrusion column extruding the floating slag, the two extrusion columns first use their minor arc surfaces to collect a large amount of floating slag, and then gradually reduce the distance between the two extrusion surfaces, better realizing the extrusion of the floating slag.

[0009] Furthermore, the distance between the plane where the inferior arc of the extrusion column is located and the plane where the superior arc of the opposite extrusion column is located is 0 to 0.5 mm. Preferably, it is 0.001 to 0.5 mm. This distance setting enables the two extrusion columns to form a highly conforming extrusion surface for the scum during rotation. When the scum passes through this narrow gap, it is subjected to a more concentrated and powerful extrusion force, which promotes the more complete extrusion of the oil droplets in the scum, significantly improving the separation efficiency of oil and suspended particles, making the oil collected in the oil storage tank purer, and reducing the oil content of the suspended particles in the slag storage tank.

[0010] Furthermore, two rotating shafts are rotatably connected in the filter oil tank. Driven gears are fixedly connected to both rotating shafts, and the two driven gears mesh with each other. A power mechanism for driving one of the driven gears to rotate is provided on the outer wall of the treatment tank. Fixing holes are provided on the extrusion columns, and the fixing holes are concentric with the superior arc and the inferior arc. The two extrusion columns are fixedly connected to the two rotating shafts through the fixing holes respectively. Through the meshing of the driven gears with each other, it is ensured that the two extrusion columns can rotate stably and synchronously in opposite directions, guaranteeing the continuity and stability of the extrusion action on the scum and improving the separation effect. The extrusion columns are fixedly connected to the rotating shafts through the fixing holes, which facilitates the installation and disassembly of the extrusion columns and is conducive to the daily maintenance and repair of the equipment.

[0011] Furthermore, the power mechanism includes a motor and a driving gear provided on the output shaft of the motor. The driving gear is connected with a gear transmission group, and one of the transmission gears in the gear transmission group meshes with one of the driven gears. The motor transmits power through the driving gear, the gear transmission group and the meshing of the driven gears. The transmission efficiency is high, and it can stably provide power for the rotation of the extrusion columns.

[0012] Furthermore, oil inlet holes are provided on the outer wall of the extrusion column. A cavity communicating with the oil inlet holes is provided inside the extrusion column, and the bottom of the cavity communicates with an oil leakage hole. Through the setting of the oil inlet holes, it is helpful for the oil to quickly enter the oil storage tank from the oil inlet holes, the cavity and the oil leakage hole after the scum is extruded by the extrusion column.

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

[0014] Furthermore, a third partition plate is also provided in the treatment tank. 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, and the discharge end of the slag discharge channel communicates with the slag storage tank. A special slag storage tank is set up to uniformly collect the suspended particles after being extruded and separated by the oil filtering component, facilitating the subsequent centralized treatment of the suspended particles.

[0015] Furthermore, the driven gear is located below the oil filter box. Placing the driven gear below the oil filter box can prevent the scum in the oil filter box from interfering with the gear meshing, ensure the smoothness of the gear transmission, and extend the service life of the equipment. The scum is squeezed and the oil falls through the oil filter box to provide lubrication and cooling for the driven gear.

[0016] Furthermore, the bottom of the slag discharge channel is a downwardly inclined surface, which is conducive to the smooth passage of suspended particles through the slag discharge channel under the action of gravity, reduces the residual suspended particles in the channel, and prevents the slag discharge channel from being blocked.

[0017] Furthermore, 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. The water collector can collect water that meets the discharge standard after flotation treatment, and control the water flow through the valve to facilitate the subsequent treatment or discharge of the water that meets the standard.

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

[0019] Furthermore, the extrusion column is provided with a wear-resistant rubber sleeve. The wear-resistant rubber sleeve can effectively buffer the friction between the extrusion column and the inner wall of the oil filter box and the scum, reduce the wear rate of the extrusion column body, and extend the service life of the extrusion column; and the rubber sleeve has a certain elasticity, and in the process of squeezing the scum, it can better fit the inner wall of the oil filter box and the scum, fill the tiny gap between the extrusion column and the inner wall of the oil filter box, and make the scum bear the force more evenly, thereby improving the separation efficiency of oil and sludge and ensuring the effect of scum separation. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0021] Figure 2 for Figure 1 A schematic top view of the middle oil filter assembly;

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

[0023] Figure 4 This is a schematic structural diagram of an oil filter assembly in a wastewater treatment device according to Example 2 of the present invention. DETAILED DESCRIPTION

[0024] The following is a further detailed description through specific embodiments:

[0025] The reference numerals in the accompanying drawings of the specification include: dissolved air tank 1, treatment tank 2, mixing tank 3, first partition plate 4, air flotation tank 5, liquid level sensor 6, second partition plate 7, slag inlet channel 8, oil filter tank 9, tank 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] Embodiment 1 is basically as shown in the attached Figures 1 to 3 figures: 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 driving gear is installed on the output shaft of the motor. The transmission gear set includes a plurality of transmission gears. Both the dissolved air tank 1 and the protective box are installed on the outer wall of the treatment tank 2.

[0027] Inside the treatment tank 2, there are successively arranged a first partition plate 4, a second partition plate 7, and a third partition plate 14 that 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 that seals the tops of the mixing tank 3 and the air flotation tank 5 is fixedly connected to the second partition plate 7. The sealing plate 20 is located directly above the first partition plate 4; the dissolved air tank 1 is communicated with the mixing tank 3 through a pipeline. A filter oil assembly is installed between the second partition plate 7 and the third partition plate 14. The filter oil assembly includes an oil filter tank 9 and a slag inlet channel 8 and a slag discharge channel 12 connected thereto. The slag inlet channel 8 and the slag discharge channel 12 are respectively communicated with opposite sides of the oil filter tank 9. The ends of the slag inlet channel 8 and the slag discharge 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 discharge channel 12 away from the oil filter tank 9 are respectively communicated with the air flotation tank 5 and the slag storage tank 13. The inner bottom of the slag discharge channel 12 is an inclined plane sloping downward. The air flotation tank 5 is connected with a water collector. An electric control valve is provided at the connection between the water collector and the air flotation tank 5. A liquid level sensor 6 for detecting the water level is installed on the wall of the air 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 and speed of the motor, and is also used to receive the information of the liquid level sensor 6, control the on-off and flow rate of the electric control valve.

[0028] A support column 16 is detachably connected inside the oil storage tank 18. The top of the support column 16 is rotatably connected with two rotating shafts. The two rotating shafts penetrate the bottom of the oil filter tank 9 and extend upward. Driven gears 17 are installed on both rotating shafts. The driven gears 17 are located below the oil filter tank 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 filtering tank 9 is buckled with a tank cover 10, and oil leakage holes 15 are evenly distributed at the bottom of the oil filtering tank 9; 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 filtering tank 9, and the cross-sectional profile of the extrusion column 11 is composed of a major arc, a minor arc and two transition arcs. The two ends of the transition arc are respectively and smoothly connected to the ends of the major arc and the minor arc. 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 directions of the transition arc and the minor arc are opposite to that of the major arc; the minor arc surface of one extrusion column 11 faces the major arc surface of the other extrusion column 11, and the distance between the minor arc surface of the extrusion column 11 and the major arc surface of the extrusion column 11 facing it is 0.001 - 0.5 mm. The minor arc surface of the extrusion column 11 is attached to the inner wall of the oil filtering tank 9, and the lower surface of the extrusion column 11 is attached to the inner bottom of the oil filtering tank 9; fixing holes are provided on the extrusion column 11, and the fixing holes are concentric with the major arc and the minor arc. The two extrusion columns 11 are respectively fixedly connected to the two rotating shafts through the fixing holes.

[0030] The specific implementation process is as follows: The oily wastewater is transported to the mixing tank 3 of the treatment tank 2 through a pipeline. At the same time, the dissolved air tank 1 starts to work, dissolving a large amount of air into the water under a certain pressure to form dissolved air water, and injecting it into the mixing tank 3 through a connecting pipeline. The oily wastewater and the dissolved air water are fully stirred and mixed in the mixing tank 3, creating conditions for subsequent air flotation treatment.

[0031] The mixed water flows from the mixing tank 3 into the air flotation tank 5 through the first partition plate 4. In the air flotation tank 5, the dissolved air water suddenly decompresses, and the supersaturated air in it 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 an air flotation body with a specific gravity less than that of water. Under the action of buoyancy, the air flotation body floats to the water surface of the air flotation tank 5, forming floating scum.

[0032] As the air flotation process continues, the floating scum on the water surface is pushed by the water flow and enters the oil filtering tank 9 of the oil filtering assembly through the slag inlet channel 8. Start the motor in the protective box, and the output shaft of the motor drives the driving gear to rotate. The driving gear drives one of the driven gears 17 to rotate through the transmission gear set. Since the two driven gears 17 are meshed with each other, the two rotating shafts drive the two extrusion columns 11 to rotate synchronously and in opposite directions. When the floating scum enters the oil filtering tank 9, the two extrusion columns 11 start to work. First, the minor arc surfaces of the two extrusion columns 11 collect a large amount of floating scum. As the extrusion columns 11 rotate, the distance between the extrusion surfaces of the two extrusion columns 11 gradually decreases. The floating scum is extruded under the extrusion of the transition arc and the minor arc of the two extrusion columns 11, and the oil is squeezed out from the suspended particulate matter. Oil inlet holes are provided on the outer wall of the extrusion column 11, and the squeezed oil directly enters the oil storage tank 18 through the liquid leakage holes or enters the cavity inside the extrusion column 11 through the oil inlet holes, and then flows into the oil storage tank 18 through the oil leakage holes 15 at the bottom of the oil filtering tank 9.

[0033] After the oil is removed from the suspended particulate matter, due to the loss of the viscosity of the oil, it slides into the slag storage tank 13 along the inclined surface at the bottom of the slag discharge channel 12 under the push of the extrusion column 11. The inclined surface design at the bottom of the slag discharge channel 12 enables the suspended particulate matter to slide smoothly under the action of gravity, reducing the residue in the channel and preventing blockage.

[0034] After the water treated in the air flotation tank 5 meets the discharge standard, the controller controls the electric control valve to open according to the water level information of the air flotation tank 5 monitored in real time by the liquid level sensor 6. The treated water is collected by the water collector for subsequent treatment or discharge. At the same time, the controller will automatically adjust the rotational speed of the electric control valve and the motor according to the water level feedback by the liquid level sensor 6, avoiding water entering the slag inlet channel 8 due to too high water level. At the same time, the generation speed of the floating slag is judged through the rising speed of the liquid level, and then the rotational speed of the motor is adjusted. When the liquid level rises quickly, the rotational speed of the motor is appropriately increased to speed up the treatment speed of the floating slag; when the liquid level rises slowly, the rotational speed of the motor is reduced to save energy.

[0035] The difference between Example 2 and Example 1 is only that: a wear-resistant rubber sleeve 19 is sleeved on the extrusion column 11, as shown in the appendix Figure 4 as shown.

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

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

[0038] The above are only the embodiments of the present invention. Common knowledge such as specific structures and characteristics known in the solutions is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A wastewater treatment device, comprising a treatment tank, wherein the treatment tank is provided with a first partition plate and a second partition plate which divide the treatment tank into a mixing tank, an air flotation tank and an oil storage tank; The feature is that: a sealing plate for sealing the top of the mixing tank and the air 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, and the oil filter assembly includes an oil filter box and a slag inlet channel and a slag discharge channel connected thereto, the slag inlet channel and the slag discharge channel are respectively connected to the opposite sides of the oil filter box, and oil leakage holes are evenly distributed on the bottom of the oil filter box; two extrusion columns with opposite directions are rotatably connected in the oil filter box, and the length direction of the extrusion column 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, and the two ends of the transition arc are smoothly connected to the ends of the major arc and the minor arc respectively, the minor arc is longer than the major arc, and 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 surface where the minor arc of one extrusion column is located is opposite to the surface where the major arc of the other extrusion column is located, the surface where the minor arc of the extrusion column is located 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.

2. A wastewater treatment device according to claim 1, characterized in that: The distance between the surface where the inferior arc of the extrusion column is located and the surface where the superior arc of the extrusion column directly facing it is located is 0 to 0.5 mm.

3. A wastewater treatment device according to claim 2, characterized in that: Two rotating shafts are rotatably connected in the oil filter box, and driven gears are fixedly connected to the two rotating shafts. The two driven gears are meshed 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. A fixing hole is provided on the extrusion column, and the fixing hole is cocentric with the major arc and the minor arc. The two extrusion columns are fixedly connected to the two rotating shafts through the fixing holes.

4. A wastewater treatment device according to claim 3, characterized in that: The power mechanism comprises a motor and a driving gear arranged on an output shaft of the motor, wherein the driving gear is connected to a gear transmission group, and a transmission gear in the gear transmission group is meshed with one of the driven gears.

5. A wastewater treatment device according to claim 4, characterized in that: An oil inlet hole is arranged on the outer wall of the extrusion column, a cavity connected with the oil inlet hole is arranged inside the extrusion column, and the bottom of the cavity is connected with the oil leakage hole.

6. A wastewater treatment device according to claim 5, characterized in that: A third partition plate is also provided in the treatment tank, 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, and the discharge end of the slag discharge channel is connected to the slag storage tank.

7. A wastewater treatment device according to claim 6, characterized in that: The driven gear is located below the oil filter box.

8. A wastewater treatment device according to claim 7, characterized in that: The bottom of the slag discharge channel is a downwardly inclined slope, the air flotation tank is connected with a water collector, and a valve is provided at the connection point between the water collector and the air flotation tank.

9. A wastewater treatment device according to claim 8, characterized in that: A liquid level sensor for detecting the water level is provided on the wall of the flotation tank. The valve is an electrically controlled valve. The electrically controlled valve, the liquid level sensor and the motor are connected to the same controller. The controller is used to control the on / off and rotation speed of the motor, and is also used to receive information from the liquid level sensor and control the on / off and flow rate of the electrically controlled valve.

10. A wastewater treatment device according to claim 9, characterized in that: The extrusion column is sleeved with a wear-resistant rubber sleeve.

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