An automatic oil scraping device, system and method for oily sewage

Abstract

The present application relates to an automatic oil scraping device, system and method for oily sewage. The automatic oil scraping device comprises a support, a transmission mechanism, a plurality of oil scraping assemblies and a stopper. The support is fixedly connected to an oil-water separation tank. The transmission mechanism is installed on the support. The plurality of oil scraping assemblies are arrayed on the transmission mechanism. The oil scraping assembly comprises a connecting rod, a connecting shaft and an oil scraping bucket. The connecting rod is installed on the synchronous belt and perpendicular to the synchronous belt. The connecting rod is provided with a sliding groove for the connecting shaft to slide along its own direction. The connecting shaft is rotatably connected to the outer wall of the oil scraping bucket. The stopper is installed on the support or the oil storage tank. The present application drives the plurality of oil scraping assemblies to move through the transmission mechanism, and then scrapes the oil in the oily sewage. When the oil scraping bucket moves to the directly above the oil storage tank, the oil scraping bucket is turned over under the action of the stopper, and the oil in the oil scraping bucket is completely poured into the oil storage tank. The automatic oil scraping device of the present application has the characteristics of precise oil scraping and high oil recovery rate.

Description

Technical Field

[0001] The present invention relates to an automatic oil scraping device, in particular to an automatic oil scraping device for oily wastewater, an automatic oil scraping system for oily wastewater, and an automatic oil scraping method for oily wastewater. Background Art

[0002] Leftover food and beverages in domestic and restaurant wastewater can contain large amounts of grease, forming oily wastewater that cannot be discharged directly into nearby water sources. If oily wastewater is not treated promptly, it will produce odor and cause greater pollution to the atmosphere, soil, and water sources.

[0003] Currently, oily wastewater treatment generally involves oil recovery and wastewater discharge. Oil recovery typically involves static sedimentation, purification, or centralized recovery and treatment (such as decomposition of organic matter followed by centralized landfill). Centralized treatment of oily wastewater not only wastes significant amounts of nutrients but also easily causes secondary pollution.

[0004] During the purification and recovery process of static sedimentation, oily wastewater is collected and collected in an oil storage device through an oil suction device or scraping device. Existing scraping devices can only scrape the oil from the top layer of the oily wastewater, and the scraped oil rarely meets the recovery standards (if the oil content in the scraped oily wastewater is below the discharge standard, it can be directly discharged). This increases the workload for further oil processing and reduces the efficiency of oil recovery. Summary of the Invention

[0005] Based on this, it is necessary to provide an automatic oil scraping device, system and method for oily wastewater to address the problem of low oil scraping accuracy in existing oil scraping devices.

[0006] The present invention is achieved through the following technical solutions: An automatic oil scraping device for oily wastewater includes a bracket, a transmission mechanism, multiple oil scraping components, a gear lever, multiple pressure sensors, a liquid level meter and a controller.

[0007] The bracket is fixedly connected to the oil-water separation box. The transmission mechanism is mounted on the bracket. The transmission mechanism includes a motor, a synchronous belt, and two synchronous pulleys. The two synchronous pulleys are rotatably connected to the bracket. The synchronous belt engages with the outer sides of the two synchronous pulleys. The motor is fixedly connected to the bracket, and the rotating shaft of the motor is fixedly connected to the rotating shaft of one of the synchronous pulleys to drive the two synchronous pulleys to rotate synchronously. The bottom surface of the synchronous belt is parallel to the horizontal plane or inclined upward along the transmission direction of the bottom surface of the synchronous belt. An array of multiple scraper assemblies is mounted on the synchronous belt to scrape the oil in the oil-water separation box. The scraper assembly includes a connecting rod, a connecting shaft, and an oil scraper barrel. The connecting rod is mounted on the synchronous belt and is perpendicular to the synchronous belt. A sliding groove is provided along the connecting rod in its direction for the connecting shaft to slide. The length of the connecting rod is no greater than the minimum spacing between the synchronous belt and the oil-water separation box. The connecting shaft is parallel to the rotating shaft of the motor and is rotatably connected to the outer wall of the oil scraper barrel. The rotating surface of the oil scraper barrel is parallel to the rotating surface of the synchronous pulley. The overall density ρ of the oil scraper barrel and the connecting shaft meets the condition:

[0008] ρ=(1-w b cotθ / h b )V b ρ w / V t

[0009] Among them, w b is the top diameter or width of the oil scraper barrel, θ is the angle between the opening direction of the oil scraper barrel and the horizontal plane when the center of gravity of the oil scraper barrel is used as the support point, and h ... b is the height of the oil scraper barrel, V b is the total volume of the scraper barrel when it is filled with liquid, ρ w is the density of water, V t is the total volume of the oil scraper barrel and the connecting shaft.

[0010] One end of the lever is mounted on the bracket or oil tank, and the other end faces the transmission mechanism. The lever is located in the moving path of the oil scraper barrel and is used to drive the oil scraper barrel to flip so that the liquid in the oil scraper barrel flows into the oil tank. The distance d between the lever and the timing belt meets the following conditions:

[0011] d cmax -w b / 2<d<d cmax

[0012] Among them, d cmax It is the maximum distance between the connecting shaft and the fixing belt.

[0013] The automatic oil scraping device uses a transmission mechanism to drive multiple oil scraping components, which then scrape oil from the oily wastewater through an oil scraper barrel. When the scraper barrel reaches directly above the oil storage tank, a lever activates the barrel to flip, emptying the oil into the tank. This automatic oil scraping device features precise scraping and a high oil recovery rate, meeting the treatment requirements for oily wastewater and ensuring that it meets discharge standards.

[0014] In one embodiment, each pressure sensor is mounted at the bottom of an oil scraper drum to measure the total weight of the oil in the oil scraper drum.

[0015] In one embodiment, when the shift lever is mounted on the bracket, a diversion rod is mounted on the shift lever, and the diversion rod is used to divert the oil on the shift lever into the oil storage tank.

[0016] In one embodiment, the liquid level meter is installed in the oil-water separation tank to detect the depth of the oily wastewater in the oil-water separation tank.

[0017] In one embodiment, the controller is configured to: 1. determine whether the oily wastewater in the oil-water separator tank has reached a preset height, and if so, control the motor to start. Otherwise, the oily wastewater is replenished into the oil-water separator tank. 2. determine whether the total weight of the oil in all oil storage tanks within a time period is below a preset threshold, and if so, control the motor to stop.

[0018] The present invention also provides an automatic oil scraping system for oily wastewater, which includes an automatic oil scraping device, an oil-water separation box, an oil storage tank, a water inlet device, a discharge device and a grid box.

[0019] The automatic oil scraper is used to scrape the oil from the oil-water separator tank. The water inlet is connected to the oil-water separator tank and is used to transport oily wastewater into the tank. The discharge device is connected to the bottom of the oil-water separator tank and is used to discharge sludge or wastewater from the tank.

[0020] In one embodiment, the water inlet device includes a sludge pump, a water inlet pipe, and a first electric valve. The input end of the water inlet pipe is connected to the sludge pump, and the output end of the water inlet pipe is connected to the oil-water separator tank. The first electric valve is installed on the water inlet pipe to control the on / off state of the water inlet pipe. The sludge pump is installed in a sump for storing oily wastewater.

[0021] In one embodiment, a screen box is connected between the oil-water separator and the water inlet device to separate solid impurities from the oily wastewater. The screen box includes a housing, a screw conveyor mechanism, an output pipe, a hollow pipe, a waste slag bucket, and two electric valves. The hollow pipe is housed within the housing. The top of the hollow pipe is connected to the output end of the water inlet pipe, and the bottom of the hollow pipe is connected to the input end of the screw conveyor mechanism. The bottom end of the housing is connected to the top of the output pipe. The bottom end of the output pipe is connected to the oil-water separator. The output end of the screw conveyor mechanism extends obliquely upward through the housing to connect to the waste slag bucket.

[0022] In one embodiment, the discharge device includes a sewage pump and a drainage pipe. One end of the drainage pipe is connected to the bottom of the oil-water separation tank, and the other end of the drainage pipe is connected to the sewage pump.

[0023] The present invention also provides an automatic oil scraping method for oily wastewater, which includes the following steps:

[0024] S1: Collect the depth h of oily wastewater in the oil-water separation box at a preset height h e The oil content ω at the location and the total weight G of the oil in all the oil scraper barrels.

[0025] S2: Determine whether the depth h reaches a preset height h1. If so, start the automatic oil scraping device to scrape the oil in the oil-water separation box into the oil storage tank. Otherwise, add oily wastewater to the oil-water separation box until the depth h reaches h1.

[0026] S3: Determine whether the total weight G of the oil is lower than a preset threshold value G1 within a time period t1, and if so, turn off the automatic oil scraping device.

[0027] S4: Determine whether the oil content ω is lower than a preset threshold ω1. If so, control the start-up of the discharge device until all the oily wastewater with an oil content lower than ω1 is discharged.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The automatic oil scraping device of the present invention drives the movement of multiple oil scraping components through a transmission mechanism, and then scrapes the oil in the oily wastewater through an oil scraping barrel. When the oil scraping barrel moves to the top of the oil storage tank, the oil scraping barrel flips under the action of the gear lever, and all the oil in it is dumped into the oil storage tank. The above-mentioned automatic oil scraping device has the characteristics of precise oil scraping and high oil recovery rate, which can meet the treatment requirements of oily wastewater and achieve standard discharge of oily wastewater. In addition, by setting a controller to realize automatic adjustment of the automatic oil scraping device, the water inlet and discharge of the oil-water separation are controlled, which reduces the operating cost of the automatic oil scraping device and improves the treatment efficiency of oily wastewater.

[0030] 2. The automatic oil scraping system of the present invention can not only scrape the oil from the oily wastewater in real time, but also pre-degrade the oily wastewater through the grille box, reducing the amount of waste residue after the oily wastewater is stratified in the oil-water separation box, preventing the waste residue from accumulating in the oil-water separation box and being difficult to discharge. At the same time, by adjusting the water inlet rate of the water inlet device, the liquid level of the oily wastewater is always within the processing range of the automatic oil scraping device, thereby improving the efficiency of oil scraping. Finally, the oily wastewater that meets the discharge standards is completely discharged through the discharge device, and the electric valve 2 is closed at the same time, accumulating the deslagging oily wastewater in the box body of the grille box. After the oily wastewater is discharged, it is replenished into the oil-water separation box at one time, thereby improving the overall treatment efficiency of the oily wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the cross-sectional structure of the automatic oil scraping system for oily wastewater according to Example 1 of the present invention;

[0032] Figure 2 for Figure 1 A three-dimensional structural diagram of the oil scraping assembly;

[0033] Figure 3 for Figure 1 Another three-dimensional structural diagram of the oil scraping assembly;

[0034] Figure 4 for Figure 1 Three-dimensional structure diagram of the hollow tube;

[0035] Figure 5 This is a flow chart of the automatic oil scraping method for oily wastewater according to Example 1 of the present invention.

[0036] Description of main component symbols

[0037] The numbers in the figure are: 1. bracket; 2. transmission mechanism; 21. synchronous belt; 22. synchronous wheel; 3. oil scraper assembly; 31. connecting rod; 32. connecting shaft; 33. oil scraper barrel; 4. gear lever; 5. pressure sensor; 6. liquid level gauge; 10. automatic oil scraper device; 20. oil-water separation box; 30. oil storage tank; 40. water inlet device; 401. sludge pump; 402. water inlet pipe; 403. electric valve one; 50. discharge device; 501. sewage pump; 502. drainage pipe; 60. grille box; 601. box body; 602. spiral conveying mechanism; 603. output pipe; 604. hollow pipe; 605. waste residue barrel; 606. electric valve two.

[0038] The above description of the main component symbols is combined with the accompanying drawings and specific embodiments to further illustrate the present invention in detail. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Example 1

[0043] See also Figure 1 , which is a schematic cross-sectional view of the automatic oil scraping system for oily wastewater according to this embodiment. The automatic oil scraping system comprises an automatic oil scraping device 10, an oil-water separator tank 20, an oil storage tank 30, a water inlet device 40, a discharge device 50, and a screen box 60. The automatic oil scraping device 10 is mounted above the oil-water separator tank 20 to scrape the oil from the tank.

[0044] The automatic oil scraping device 10 includes a bracket 1, a transmission mechanism 2, an oil scraping assembly 3, a gear lever 4, a pressure sensor 5, a liquid level meter 6 and a controller (not shown).

[0045] Bracket 1 is fixedly connected to the oil-water separator tank 20. Bracket 1 can be assembled by splicing together multiple square tubes, round tubes, or plates. The splicing methods include fixed and detachable connections, such as welding, clamping, or screwing. Bracket 1, as the supporting component of the automatic oil scraper device 10, can be made of metal materials such as stainless steel and aluminum alloy, or non-metallic materials such as cement and wood.

[0046] The transmission mechanism 2 is mounted on the bracket 1. The transmission mechanism 2 includes a motor (not shown), a synchronous belt 21 and two synchronous wheels 22. The two synchronous wheels 22 are rotatably connected to the bracket 1. The synchronous belt 21 is engaged with the outer sides of the two synchronous wheels 22. The motor is fixedly connected to the bracket 1, and the rotating shaft of the motor is fixedly connected to the rotating shaft of one of the synchronous wheels 22, which is used to drive the synchronous wheel 22 to rotate, and then drive the two synchronous wheels 22 to rotate synchronously through the synchronous belt 21. The bottom surface of the synchronous belt 21 is parallel to the horizontal plane or is tilted upward along the transmission direction of the bottom surface of the synchronous belt. In other embodiments, the synchronous belt 21 and the synchronous wheels 22 can also be replaced by chains and sprockets.

[0047] Please combine Figure 2 , which is Figure 1 A three-dimensional structural diagram of the oil scraper assembly in FIG. A plurality of oil scraper assemblies 3 are mounted in an array on the synchronous belt 21 and are used to scrape out the oil in the oil-water separation box 20. The oil scraper assembly 3 includes a connecting rod 31, a connecting shaft 32, and an oil scraper barrel 33. The connecting rod 31 is mounted on the synchronous belt 21 and is perpendicular to the synchronous belt 21. The connecting rod 31 is provided with a slide groove for the connecting shaft 32 to slide along its own direction. The length of the connecting rod 31 is not greater than the minimum distance between the synchronous belt 21 and the oil-water separation box 20, so that the connecting rod 31 does not contact the oil-water separation box 20 during movement. The connecting rod 31 can be a solid round rod or a square rod, and the slide groove is provided on the side of the connecting rod 31 close to the oil-water separation box 20. When the synchronous belt 21 is tilted, the connecting rod 31 can also be tilted and fixed to the synchronous belt 21 so that when the connecting rod 31 is located directly above or directly below the synchronous belt, it is in a vertical state, that is, perpendicular to the liquid surface of the oily wastewater.

[0048] The connecting shaft 32 is parallel to the motor's rotational axis and is rotatably connected to the outer wall of the oil scraper drum 33. One end of the connecting shaft 32 slides within a chute, while the other end is rotatably connected to the center of the outer wall of the oil scraper drum 33. The rotating surface of the oil scraper drum 33 is parallel to the rotating surface of the synchronous wheel 22. The oil scraper drum 33 can be square or cylindrical.

[0049] Please combine Figure 3 , which is Figure 1 In order to improve the oil scraping efficiency, the two ends of the connecting shaft 32 can be rotated to connect to an oil scraping barrel 33, and the two sides of the two oil scraping barrels 33 on the same connecting shaft 32 are close to the inner walls of the oil-water separation box 20.

[0050] In order to ensure that the oil scraper barrel 33 only scrapes out the oil but not the water layer, that is, to ensure that the oil content of the liquid scraped out by the oil scraper barrel 33 each time is not lower than a preset threshold value, the overall density of the oil scraper barrel 33 and the connecting shaft 32 can be adjusted so that the oil scraper barrel 33 does not scrape out the liquid when the oil content of the oily wastewater is lower than a preset threshold value.

[0051] Assuming that the distance between the oily wastewater level in the oil-water separation box 20 and the synchronous belt 21 is not greater than the length of the connecting rod 31, when the oil scraper barrel 33 contacts the oily wastewater, it rotates naturally under the friction between it and the oily wastewater and the driving force of the transmission mechanism. At this time, the opening height of the oil scraper barrel 33 is proportional to the buoyancy F it receives. f and the weight m of the scraper barrel 33 b , the gravity m of the connecting shaft 32 c And the friction force F between the connecting shaft 32 and the slide groove s Assume that the scraper barrel 33 is a square barrel with an opening width of w b , height h b When the oil scraper barrel 33 floats on the oily wastewater, the angle formed between it and the liquid surface of the oily wastewater is θ. The oil content in the oily wastewater is 0. At this time, the open bottom side of the oil scraper barrel 33 should just coincide with the liquid surface of the oily wastewater.

[0052] At this time, the volume of the scraper barrel 33 in the oily wastewater can be expressed as:

[0053] V s =(1-w b cotθ / h b )V b

[0054] At this time, the buoyancy of the oil scraper barrel 33 is equal to the total weight of the oil scraper barrel 33 and the connecting shaft 32. f It can be expressed as:

[0055] F f =ρ w gV s

[0056] According to the density formula, the overall density ρ of the oil scraper barrel 33 and the connecting shaft 32 is expressed as:

[0057] F f =ρV t

[0058] After integration, it can be seen that the overall density ρ of the oil scraper barrel 33 and the connecting shaft 32 meets the condition:

[0059] ρ=(1-w b cotθ / h b )V b ρ w / V t

[0060] In the above formula, w b is the top diameter or width of the oil scraper barrel, θ is the angle between the opening direction of the oil scraper barrel and the horizontal plane when the center of gravity of the oil scraper barrel is used as the support point, and h ... bis the height of the oil scraper, g is the acceleration due to gravity, V b is the total volume of the scraper barrel when it is filled with liquid, ρ w is the density of water, V t It is the total volume of the oil scraper barrel and the connecting shaft.

[0061] The oil scraper assembly 3 moves along the rotational direction of the timing belt 21. The opening of the oil scraper barrel 33 is vertically upward when not in contact with the oily wastewater. When the oil scraper barrel 33 contacts the oily wastewater, its opening tilts upward in the direction of movement. If the oil content in the top layer of the oily wastewater is lower than the discharge standard, meaning the density of the oily wastewater is greater than a preset density, the connecting shaft 32, acting under buoyancy, moves along the chute toward the timing belt 21 until the connecting shaft 32 reaches the top of the chute. The opening of the oil scraper barrel 33 remains at or above the surface of the oily wastewater, and no liquid is scraped out. If the density of the oily wastewater is lower than the preset density, the oil scraper barrel 33 sinks until its opening is below the oil layer, storing the oil within the barrel. At this point, the friction between the connecting shaft 32 and the chute is directed upward, preventing the barrel from sinking further. Buoyancy ensures that the opening of the oil scraper barrel 33 remains above the surface of the water layer, allowing the oil to accumulate along its opening within the barrel. When the oil scraping barrel 33 continues to move until it exceeds the liquid level of the oily wastewater, the oil scraping barrel 33 returns to its opening facing upward under the action of gravity, and scrapes out the oil in the oily wastewater.

[0062] One end of the shift lever 4 is mounted on the bracket 1 or the oil tank 30, and the other end faces the transmission mechanism 2. The shift lever 4 is located in the movement path of the oil scraper drum 33. The shift lever 4 is used to drive the oil scraper drum 33 to flip directly above the oil tank 30, allowing the liquid in the oil scraper drum 33 to flow into the oil tank 30. The distance d between the shift lever 4 and the timing belt 21 satisfies the following condition:

[0063] d cmax -w b / 2<d<d cmax

[0064] Among them, d cmax It is the maximum distance between the connecting shaft and the fixing belt.

[0065] When the gear lever 4 is mounted on the bracket 1, a drainage rod is installed on the gear lever 4 to drain the oil on the gear lever into the oil storage tank 30. When the gear lever 4 drives the oil scraper barrel 33 to flip, part of the liquid in the oil scraper barrel 33 adheres to the gear lever 4 and flows or drips downward along the gear lever 4. By providing the drainage rod, all the liquid on the gear lever 4 is drained into the oil storage tank 30, which can avoid oil waste and improve the oil recovery rate.

[0066] Each pressure sensor 5 is mounted at the bottom of an oil scraper drum 33 and is used to measure the total weight of the oil within the drum 33. The pressure sensor 5 can be a piezoelectric, piezoresistive, electromagnetic, or capacitive pressure sensor, as long as it can measure the oil weight in real time. This embodiment uses a fiber optic pressure sensor, which is compact and highly accurate, ensuring precise measurement of the oil within the drum 33.

[0067] The liquid level meter 6 is installed in the oil-water separation tank 20 and is used to detect the depth of the oily wastewater therein. The liquid level meter 6 can be a communicating vessel type, a differential pressure type, a capacitance type, or an ultrasonic type, as long as it can measure the depth of the oily wastewater. This embodiment uses an ultrasonic level meter with a signal of YEH3000X2. It not only has high measurement accuracy, but also operates in acidic and alkaline environments, has high corrosion resistance, and is suitable for the working environment of oil-water separation.

[0068] The controller is used to: 1. Determine whether the oily wastewater in the oil-water separation box 20 has reached a preset height, and to control the motor to start. When the oily wastewater reaches the preset height, the lowest point that the connecting shaft 32 can reach is just above the liquid surface of the oily wastewater, so that the scraper barrel 33 can scrape out the oil in the oily wastewater. Otherwise, the oily wastewater is replenished into the oil-water separation box 20. In actual applications, the oily wastewater may be input into the oil-water separation box in real time or at intervals. During the real-time scraping process of the automatic scraping device 10, the liquid level of the oily wastewater may gradually decrease. In order to meet the scraping conditions of the oily wastewater, the liquid level of the oily wastewater needs to be kept at or above the preset height.

[0069] Second, the system determines whether the total weight of the oil in all oil storage tanks is below a preset threshold within a time period. If so, the motor is controlled to stop. If the oily wastewater in the oil-water separator 20 has completed the oil-water separation process, i.e., the total oil content has reached the discharge standard, the automatic oil scraper 10 is unable to scrape the oil, and the total amount of oil in all oil storage tanks (partially adhering to the inner wall of the oil storage barrel) remains unchanged, the automatic oil scraper 10 is stopped, thus saving operating costs. Simultaneously, the oily wastewater in the oil-water separator 20 can be discharged all at once.

[0070] The controller can be a control chip, or an intelligent control box, a computer, etc., as long as it can control the operation of the automatic oil scraping device according to a preset program.

[0071] The automatic oil scraping device of this embodiment drives multiple oil scraping assemblies 3 via a transmission mechanism 2, which in turn scrapes the oil from the oily wastewater through an oil scraper barrel 33. When the oil scraper barrel 33 moves directly above the oil storage tank 30, the shift lever 4 causes the scraper barrel 33 to flip, dumping all the oil contained therein into the oil storage tank 30. The automatic oil scraping device of this embodiment features precise oil scraping and a high oil recovery rate, meeting the treatment requirements for oily wastewater and ensuring that the oily wastewater meets discharge standards. Furthermore, a controller is provided to automatically adjust the automatic oil scraping device, controlling the inflow and outflow of oil-water separation water, thereby reducing the operating costs of the automatic oil scraping device and improving the treatment efficiency of oily wastewater.

[0072] The oil-water separator 20 is used to separate oily wastewater into oil and water layers through static sedimentation. In this embodiment, a square oil-water separator 20 is used, allowing the oil scraper 33 to move along its length. This increases the contact area between the scraper 33 and the oily wastewater, thereby improving oil scraping efficiency. Inclined surfaces are provided on both sides of the top of the oil-water separator 20. A second shift lever is also mounted on the inclined surface facing away from the oil storage tank 30. This shift lever is positioned in the movement path of the oil scraper 33 to pre-rotate the scraper 33 in the inclined direction, preventing friction between the scraper 33 and the oily wastewater from driving the scraper 33's rotation. The inclined surface on the side closest to the oil storage tank 30 allows the scraper 33 to move along the inclined surface, preventing interference from the sidewalls of the oil-water separator 20 and increasing the range of movement of the scraper 33 within the oil-water separator 20. At the same time, when the oil scraper moves along the inclined surface, the oil at the edge of the oil-water separation box 20 can be scraped out, overcoming the problem that the oil is collected at the edge and cannot be scraped out.

[0073] The oil storage tank 30 is located outside the oil-water separator tank 20 and is used to store the oil scraped from the oil-water separator tank 20. In this embodiment, the oil-water separator tank 20 is made of stainless steel, while the oil storage tank 30 is made of plastic. The oil-water separator tank 20 must not only be corrosion-resistant to handle the oily wastewater for extended periods of time, but also meet the rigidity requirements for supporting the automatic oil scraping device. Of course, in other embodiments, the oil-water separator tank 20 can also be made of cement or other metal materials coated with an anti-corrosion material. The oil storage tank 30 can also be made of other materials, such as stainless steel or ceramic.

[0074] The water inlet device 40 is connected to the oil-water separator tank 20 and is used to transport oily wastewater into the oil-water separator tank 20. The water inlet device 40 includes a sludge pump 401, a water inlet pipe 402, and an electric valve 403. The input end of the water inlet pipe 402 is connected to the sludge pump 401, and the output end of the water inlet pipe 402 is connected to the oil-water separator tank 20. The electric valve 403 is installed on the water inlet pipe 402 and is used to control the on / off state of the water inlet pipe 402. The sludge pump 401 is installed in a sump for storing oily wastewater. Starting the sludge pump 401 directs the oily wastewater in the sump into the oil-water separator tank 20. A controller can control the start and stop states of the sludge pump 401 and the electric valve 403 to control the efficiency of the oily wastewater intake.

[0075] Please combine Figure 4 , which is Figure 1 A three-dimensional structural diagram of the hollow pipe. The grid box 60 is connected between the oil-water separation box 20 and the water inlet device 40 and is used to separate solid impurities from the oily wastewater. The grid box 60 includes a box body 601, a spiral conveying mechanism 602, an output pipe 603, a hollow pipe 604, a waste residue bucket 605, and a second electric valve 606. The hollow pipe 604 is housed in the box body 601. The top end of the hollow pipe 604 is connected to the output end of the water inlet pipe 402, and the bottom end of the hollow pipe 604 is connected to the input end of the spiral conveying mechanism 602. The bottom end of the box body 601 is connected to the top end of the output pipe 603. The bottom end of the output pipe 603 is connected to the oil-water separation box 20. The second electric valve 606 is installed on the output pipe 603 and is used to control the on / off state of the output pipe 603. The output end of the spiral conveying mechanism 602 passes obliquely upward through the box body 601 and is connected to the waste residue bucket 605. The oily wastewater is introduced into the hollow tube 604 through the inlet pipe 402. The liquid oil and water therein flows through the holes of the hollow tube 604 into the box 601 and then into the oil-water separation box 20 through the outlet pipe 603. The solid waste in the oily wastewater enters the screw conveyor mechanism 602 and is then transported to the waste residue bucket 605.

[0076] The discharge device 50 is connected to the bottom of the oil-water separator tank 20 and is used to drain the sludge or sewage within the oil-water separator tank 20. The discharge device 50 includes a sewage pump 501 and a drain pipe 502. One end of the drain pipe 502 is connected to the bottom of the oil-water separator tank 20. The other end of the drain pipe 502 is connected to the sewage pump 501. The discharge device 50 can completely discharge the oily sewage within the oil-water separator tank 20 when the oily sewage reaches the discharge standard.

[0077] The automatic oil scraping system of this embodiment not only scrapes oil from the oily wastewater in real time, but also pre-degrades the oily wastewater through the grid box 60, reducing the amount of waste residue after the oily wastewater is separated and preventing waste residue from accumulating in the oil-water separator 20 and becoming difficult to discharge. Furthermore, by adjusting the water inlet rate of the water inlet device 40, the liquid level of the oily wastewater is always within the treatment range of the automatic oil scraping device 10, thereby improving the efficiency of oil scraping. Finally, the discharge device 50 discharges all oily wastewater that meets the discharge standards, and the electric valve 2 606 is closed simultaneously, allowing the de-degraded oily wastewater to accumulate in the box 601. After the oily wastewater is discharged, it is replenished to the oil-water separator 20 at one time, thereby improving the overall treatment efficiency of the oily wastewater.

[0078] Please combine Figure 5 , which is a flow chart of the automatic oil scraping method for oily wastewater of this embodiment. Based on the above-mentioned automatic oil scraping system for oily wastewater, this embodiment also provides an automatic oil scraping method for oily wastewater, which includes the following process:

[0079] S1: Collect the depth h of oily wastewater in the oil-water separation box at a preset height h e The oil content ω at the location and the total weight G of the oil in all the scraper barrels. The depth of the oily wastewater can be collected by a level meter. The oil content of the oily wastewater can be collected by an oil content detector. The total weight of the oil can be collected by a pressure sensor. The preset height h e It can be set to 1 / 3 of the height of the oil-water separation tank.

[0080] S2: Determines whether the depth h reaches a preset height h1. If so, the automatic oil scraper is activated to scrape the oil from the oil-water separator tank into the oil storage tank. Otherwise, oily wastewater is added to the oil-water separator tank until the depth h reaches h1. When the oily wastewater reaches h1, it is within the automatic oil scraper's processing range. That is, when the scraper barrel is directly below the timing belt and has reached its maximum distance from the timing belt, the scraper barrel can scrape the oily wastewater.

[0081] S3: Determine whether the total weight G of the oil is below a preset threshold value G1 within a time period t1. If so, the automatic oil scraping device is shut down. After the automatic oil scraping device has operated for a period of time, a small amount of oil will remain in each scraper bucket. If the automatic oil scraping device continues to scrape oil and the weight of the oil in the scraper bucket remains unchanged within the time period, it indicates that no oil has been scraped out, indicating that the oil content at the top of the oily wastewater has reached the discharge standard. In this case, the automatic oil scraping device is shut down to save operating costs.

[0082] S4: Determine whether the oil content ω is lower than a preset threshold ω1. If so, control the start of the discharge device until all the oily wastewater with an oil content lower than ω1 is discharged. The oily wastewater gradually separates into layers of oil, water and waste residue from top to bottom in the oil-water separation box. During the separation process, there is an oil-water mixed layer between the oil layer and the water layer. As the separation process progresses, the oil-water mixed layer gradually decreases and the water layer level rises. When the oil content ω is lower than the threshold ω1, it indicates that it is at a height h e The oily wastewater below has been stratified and can be discharged directly.

[0083] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An automatic oil scraping device for oily wastewater, which is used to scrape the oil in an oil-water separation tank and guide it into an oil storage tank; characterized in that: The automatic oil scraping device comprises: a bracket fixedly connected to the oil-water separation box; A transmission mechanism is mounted on the bracket; the transmission mechanism includes a motor, a synchronous belt, and two synchronous wheels; the two synchronous wheels are rotatably connected to the bracket; the synchronous belt is engaged with the outer sides of the two synchronous wheels; the motor is fixedly connected to the bracket, and the rotating shaft of the motor is fixedly connected to the rotating shaft of one of the synchronous wheels, for driving the two synchronous wheels to rotate synchronously; the bottom surface of the synchronous belt is parallel to the horizontal plane or is arranged obliquely upward along the transmission direction of the bottom surface of the synchronous belt; A plurality of oil scraping assemblies, wherein the array of the oil scraping assemblies is mounted on the synchronous belt and is used to scrape the oil in the oil-water separation box; the oil scraping assembly comprises a connecting rod, a connecting shaft and an oil scraping barrel; the connecting rod is mounted on the synchronous belt and is perpendicular to the synchronous belt; the connecting rod is provided with a slide groove along its own direction for the sliding of the connecting shaft; the length of the connecting rod is not greater than the minimum distance between the synchronous belt and the oil-water separation box; the connecting shaft is parallel to the rotating shaft of the motor and is rotatably connected to the outer wall of the oil scraping barrel; the rotating surface of the oil scraping barrel is parallel to the rotating surface of the synchronous wheel; the overall density ρ of the oil scraping barrel and the connecting shaft satisfies the condition: Among them, w b is the top diameter or width of the oil scraper barrel, θ is the angle between the opening direction of the oil scraper barrel and the horizontal plane when the center of gravity of the oil scraper barrel is used as the support point, and h ... b is the height of the oil scraper barrel, V b is the total volume of the scraper barrel when it is filled with liquid, ρ w is the density of water, V t is the total volume of the oil scraper barrel and the connecting shaft; and A shift lever, one end of which is mounted on the bracket or the oil storage tank and the other end of which faces the transmission mechanism; the shift lever is located on the moving path of the oil scraper barrel and is used to drive the oil scraper barrel to flip so that the liquid in the oil scraper barrel flows into the oil storage tank; the distance d between the shift lever and the synchronous belt meets the following conditions: d cmax -w b / 2<d<d cmax Among them, d cmax is the maximum distance between the connecting shaft and the synchronous belt.

2. The automatic oil scraping device for oily wastewater according to claim 1, characterized in that: The oil scraping assembly further includes a plurality of pressure sensors, each of which is mounted on the bottom of one of the oil scraping barrels and is used to measure the total weight of the oil in the oil scraping barrel.

3. The automatic oil scraping device for oily wastewater according to claim 1, characterized in that: When the shift lever is mounted on the bracket, a diversion rod is mounted on the shift lever, and the diversion rod is used to divert the oil on the shift lever into the oil storage tank.

4. The automatic oil scraping device for oily wastewater according to claim 1, characterized in that: The automatic oil scraping device further comprises a liquid level meter, which is installed in the oil-water separation box and is used to detect the depth of the oily wastewater in the oil-water separation box.

5. The automatic oil scraping device for oily wastewater according to claim 1, characterized in that: The automatic oil scraping device also includes a controller, which is used to:

1. determine whether the oily wastewater in the oil-water separation tank has reached a preset height, and if so, control the motor to start; otherwise, replenish the oily wastewater into the oil-water separation tank; 2. determine whether the total weight of the oil in all the oil storage tanks within a time period is lower than a preset threshold, and if so, control the motor to stop running.

6. An automatic oil scraping system for oily wastewater, comprising an oil-water separation tank and an oil storage tank, wherein the oil-water separation tank is used to separate the oily wastewater into an oil layer and a water layer by static sedimentation; the oil storage tank is arranged outside the oil-water separation tank and is used to store the oil scraped from the oil-water separation tank; characterized in that: The automatic oil scraping system also includes: The automatic oil scraping device according to any one of claims 1 to 5, wherein the automatic oil scraping device is used to scrape out the oil in the oil-water separation box; a water inlet device, which is in communication with the oil-water separation tank and is used to transport oily wastewater into the oil-water separation tank; and A discharge device is communicated with the bottom of the oil-water separation tank and is used to discharge sludge or sewage in the oil-water separation tank.

7. The automatic oil scraping system for oily wastewater according to claim 6, characterized in that: The water inlet device includes a sludge pump, a water inlet pipe and an electric valve; the input end of the water inlet pipe is connected to the sludge pump, and the output end of the water inlet pipe is connected to the oil-water separation box; the electric valve is installed on the water inlet pipe to control the on-off state of the water inlet pipe; The sludge pump is installed in a sump for storing oily sewage.

8. The automatic oil scraping system for oily wastewater according to claim 7, characterized in that: The automatic oil scraping system also includes a grille box; the grille box is connected between the oil-water separation box and the water inlet device, and is used to separate solid impurities in the oily wastewater; the grille box includes a box body, a spiral conveying mechanism, an output pipe, a hollow pipe, a waste residue bucket and two electric valves; the hollow pipe is accommodated in the box body; the top end of the hollow pipe is connected to the output end of the water inlet pipe, and the bottom end of the hollow pipe is connected to the input end of the spiral conveying mechanism; the bottom end of the box body is connected to the top end of the output pipe; the bottom end of the output pipe is connected to the oil-water separation box; the output end of the spiral conveying mechanism obliquely passes through the box body and is connected to the waste residue bucket.

9. The automatic oil scraping system for oily wastewater according to claim 6, characterized in that: The discharge device includes a sewage pump and a drainage pipe; one end of the drainage pipe is connected to the bottom of the oil-water separation box; and the other end of the drainage pipe is connected to the sewage pump.

10. An automatic oil scraping method for oily wastewater, applied to the automatic oil scraping system for oily wastewater according to any one of claims 7 to 9, characterized in that: The automatic oil scraping method includes the following steps: S1: Collect the depth h of oily wastewater in the oil-water separation box at a preset height h e The oil content ω at the location and the total weight G of the oil in all the scraper barrels; S2: Determine whether the depth h reaches a preset height h1. If yes, activate the automatic oil scraping device to scrape the oil in the oil-water separation tank into the oil storage tank; otherwise, add oily wastewater to the oil-water separation tank until the depth h reaches h1. S3: determining whether the total weight G of the oil is lower than a preset threshold value G1 within a time period t1, and if so, shutting down the automatic oil scraping device; S4: Determine whether the oil content ω is lower than a preset threshold ω1. If yes, control the start of the discharge device until all the oily wastewater with an oil content lower than ω1 is discharged.

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