An automatic sludge discharge device, three-phase separation equipment and method for oily sewage

Abstract

This invention relates to an automatic sludge discharge device, three-phase separation equipment, and method for oily wastewater. The automatic sludge discharge device includes a discharge device, a stirring device, a pressure sensor, and a controller. The discharge device is connected to the bottom of the separation tank. The stirring device includes a motor, a rotating shaft, multiple support rods, and multiple stirring rods. The top end of the rotating shaft passes through the separation tank and is fixedly connected to the output end of the motor. Multiple support rods are arranged in a ring array at the bottom of the rotating shaft. Multiple stirring rods are arranged in an array on each support rod. The pressure sensor is fixedly installed on the support rod or stirring rod. The controller is used to control the start and stop status of the discharge device based on the pressure collected by the pressure sensor. This invention, by periodically stirring the sludge, avoids sludge coagulation and adhesion that causes blockage, and can more accurately measure the depth of the sludge layer, discharging the bottom sludge in one go. It has the advantages of more accurate discharge, avoidance of secondary pollution, and greater energy saving.

Description

Technical Field

[0001] This invention relates to an automatic sludge discharge device, and more particularly to an automatic sludge discharge device for oily wastewater, a three-phase separation device for oily wastewater, and a three-phase separation method for oily wastewater. Background Technology

[0002] Three-phase separation of oily wastewater generally involves two steps: solid-liquid separation and oil-water separation. These two steps can also be performed simultaneously as a single process. Since the density of solid impurities (sludge) in oily wastewater is significantly greater than that of water, while the density of oil is closer to that of water, the rate of solid-liquid separation is generally higher than that of oil-water separation. The denser solid impurities accumulate at the bottom of the separation equipment after settling. If the accumulated sludge is not discharged for a long time, the sludge layer will continuously rise, occupying the effective volume of the separation equipment, reducing the hydraulic retention time, and failing to meet the treatment requirements of static stratification separation. Furthermore, prolonged non-discharge of residue will affect the effluent quality, increase odor generation, clog wastewater inlet and outlet channels, and the residue may also clump together with waste oil.

[0003] Existing sludge discharge can be controlled manually or periodically. Manual control is inherently uncertain, easily leading to untimely discharge, clogging of discharge devices, and even damage to separation equipment. Periodic discharge, on the other hand, suffers from incomplete discharge and secondary pollution due to inconsistent sludge settling times, making it difficult to determine the timing (or amount) of each discharge. Summary of the Invention

[0004] Therefore, it is necessary to provide an automatic sludge discharge device, three-phase separation equipment and method for oily wastewater, which addresses the problem that sludge is difficult to discharge in a timely manner during the treatment of oily wastewater, leading to sludge blockage of treatment equipment or secondary pollution.

[0005] The present invention is achieved through the following technical solution: an automatic sludge discharge device for oily wastewater includes a discharge device, a stirring device, a pressure sensor and a controller.

[0006] The discharge device is connected to the bottom of the separation tank for discharging sludge from the tank. The agitation device includes a motor, a rotating shaft, multiple support rods, and multiple agitator rods. The rotating shaft is coaxial with the bottom of the separation tank. The top of the rotating shaft passes through the separation tank and is fixedly connected to the motor's output end. Multiple support rods are arranged in a horizontal ring at the bottom of the rotating shaft. The ends of the support rods furthest from the rotating shaft are angled downwards. Multiple agitator rods are arranged in an array on each support rod. Each agitator rod is vertically downwards. A pressure sensor is fixedly mounted on one of the support rods or agitator rods to measure the resistance value F of the oily wastewater to the agitation device at different heights during operation. n .

[0007] The controller is used for: 1. According to a preset period T c1 The stirring device is controlled to ensure uniform mixing of the sludge at the bottom of the separation tank, while the resistance value F measured by each pressure sensor is collected. n II. Based on the measured resistance value F n The corresponding sludge moisture content is looked up in a pre-stored conversion table. The conversion table represents the mapping relationship between the resistance value experienced by the agitator and the sludge moisture content. Third, the sludge depth is calculated based on the sludge moisture content at different heights. It is then determined whether the sludge depth is higher than a preset depth h0. If so, the discharge device is activated to discharge the sludge from the separation tank.

[0008] The aforementioned automatic sludge discharge device, by periodically stirring the sludge at the bottom of the separation tank, not only mixes the sludge layer evenly, preventing coagulation and adhesion that could cause blockages, but also more accurately measures the depth of the sludge layer. This allows for the complete discharge of the bottom sludge at a predetermined depth. Compared to manual sludge discharge, this automatic device discharges sludge promptly and quickly, preventing sludge from clumping, clogging the separation tank, and producing odors. Compared to timed sludge discharge, this automatic device offers more precise discharge, avoids the discharge of oil and water, prevents secondary pollution, and is also more energy-efficient, reducing operating costs.

[0009] In one embodiment, the stirring rod is an inverted pyramid or inverted cone structure.

[0010] In one embodiment, one side of the scraper is fixedly connected to the end of the support rod away from the rotation axis. The other side of the scraper is in contact with the bottom inner wall of the separation tank.

[0011] In one embodiment, a hollow shaft is coaxially disposed outside the rotating shaft and rotatably connected to the rotating shaft. The hollow shaft is fixedly connected to the separation tank.

[0012] In one embodiment, the discharge device includes a sewage pump, a sewage pipe, and an electric valve. One end of the sewage pipe is connected to the bottom of the separator, and the other end is connected to the sewage pump. The electric valve is installed on the sewage pipe and is used to control the on / off state of the sewage pipe.

[0013] The present invention also provides a three-phase separation device for oily wastewater, the three-phase separation device including an automatic sludge discharge device, a separation tank, a water inlet device, a three-way valve, a detection device, a heating device, a heat preservation device, an oil content detector, and multiple temperature sensors.

[0014] The bottom of the separator is hemispherical, a truncated pyramid, or a truncated cone. An inlet device connects to the separator to introduce oily wastewater. A three-way valve includes one input and two outputs. The input connects to the outlet of an automatic sludge removal device. One output is used for sludge or water removal, and the other for oil removal. The detection device includes a housing and a positioner. The housing is a hollow sphere. The positioner is fixedly connected to the center of the sphere to measure the housing's position in real time. The overall density of the detection device is greater than that of oil but less than that of water. The detection device is placed inside the separator to measure its own real-time position.

[0015] In one embodiment, the water inlet device includes a submersible pump, an inlet pipe, and a second electrically operated valve. The submersible pump is installed in a sump for storing oily wastewater. The inlet end of the inlet pipe is connected to the submersible pump, and the outlet end of the inlet pipe is connected to a separation tank. The second electrically operated valve is installed on the inlet pipe and is used to control the on / off state of the inlet pipe.

[0016] In one embodiment, a heating device is installed at the connection between the water inlet device and the separator tank to heat the oily wastewater entering the tank. A heat preservation device is installed on the separator tank to keep the oily wastewater inside the separator tank warm.

[0017] In one embodiment, the oil content detector is used to detect the oil content ω at the outlet of the automatic sludge removal device. o1 The temperature sensor is used to measure the real-time temperature T1 of the oily wastewater entering the tank and the average temperature T2 of the oily wastewater inside the separation tank.

[0018] The controller of the automatic sludge removal device is also used for: 1. Determining whether the temperature T1 and the average temperature T2 exceed a preset temperature range; if so, adjusting the output power of the heating or insulation device until the temperature T1 and the average temperature T2 are within the temperature range. 2. Determining whether the detection device operates within a preset cycle T. c2 If there is no change in internal height, then activate the automatic sludge discharge device and oil content detector, and determine the oil content ω. o1 Is the oil content ω higher than a preset level? sIf yes, then drain the oil; otherwise, drain the sludge or water.

[0019] The present invention also provides a three-phase separation method for oily wastewater, the three-phase separation method comprising the following steps:

[0020] S1: After heating the oily wastewater to a preset temperature range, it is introduced into a separation tank until the oily wastewater level reaches a preset height. The oily wastewater in the separation tank is kept at a constant temperature to ensure that the average temperature of the oily wastewater in the tank remains within the set temperature range. Through static sedimentation, the oily wastewater in the separation tank is separated into an oil layer, a water layer, and a sludge layer from top to bottom.

[0021] S2: Based on a preset period T c1 Oily wastewater below a preset height is stirred to ensure uniform mixing of the sludge layer. Simultaneously, the resistance value F of the oily wastewater at different heights to the stirring device is collected during the stirring process. n Then, the corresponding sludge moisture content is looked up in a conversion table. The conversion table represents the mapping relationship between the resistance value experienced by the mixing device and the sludge moisture content.

[0022] S3: Calculate the sludge depth based on the water content at different heights. When the sludge depth h is greater than a preset depth h... s At that time, the sludge is discharged, and oily wastewater is added to the separation tank until the level of the oily wastewater reaches a preset height.

[0023] S4: When the oily wastewater in the separator tank has completely separated into layers, discharge the oily wastewater from the bottom of the separator tank, and simultaneously measure the oil content ω of the oily wastewater at the bottom of the separator tank. o1 When the oil content ω o1 Oil content ω below a preset level s If necessary, the water and sludge layers in the oily wastewater will be discharged directly; otherwise, the oil layer in the oily wastewater will be recycled.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The automatic sludge discharge device of the present invention, by periodically stirring the sludge at the bottom of the separation tank, not only mixes the sludge layer evenly, preventing coagulation and adhesion that could cause blockage, but also allows for more precise measurement of the sludge layer depth. This enables the bottom sludge to be discharged in one go when the sludge layer reaches a preset depth. Compared to manual sludge discharge, the automatic sludge discharge device of the present invention can discharge sludge promptly and quickly, preventing sludge from clumping together, clogging the separation tank, and producing odors. Compared to timed sludge discharge, the automatic sludge discharge device of the present invention offers more precise discharge, avoids the discharge of oil and water, prevents secondary pollution to the environment, and is also more energy-efficient, reducing operating costs.

[0026] 2. The three-phase separation equipment of this invention preheats oily wastewater, melting the solid phase oil into liquid phase oil, preventing sludge and oil from clumping together and becoming difficult to separate. Simultaneously, an automatic sludge discharge device promptly removes sludge settled at the bottom of the separation tank and replenishes the oily wastewater, fully utilizing the effective volume of the separation tank and improving the separation efficiency of the oily wastewater. Finally, by measuring the oil content of the discharged oily wastewater in real time, the water layer and oil layer are accurately distinguished, and the oil layer is recycled, reducing secondary pollution, saving energy, and lowering treatment costs. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural schematic diagram of the three-phase separation device for oily wastewater according to Embodiment 1 of the present invention;

[0028] Figure 2 for Figure 1 A cross-sectional structural diagram of a three-phase separation device;

[0029] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure of the detection device in the middle;

[0030] Figure 4 This is a flowchart of a three-phase separation method for oily wastewater according to Embodiment 1 of the present invention.

[0031] Explanation of main component symbols

[0032] The following are the labels in the diagram: 1. Discharge device; 2. Stirring device; 21. Motor; 22. Rotating shaft; 23. Support rod; 24. Stirring rod; 25. Hollow shaft; 26. Scraper; 20. Water inlet device; 40. Detection device; 401. Shell; 402. Positioner; 50. Heating device; 60. Insulation device; 90. Separation tank.

[0033] The above description of the main component symbols, together with the accompanying drawings and specific embodiments, provides a more detailed explanation of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] Example 1

[0038] Please see Figure 1 and Figure 2 , Figure 1 This is a three-dimensional structural diagram of the three-phase separation device for oily wastewater in this embodiment; Figure 2 for Figure 1 A cross-sectional structural diagram of a three-phase separation device. The three-phase separation device includes an automatic sludge discharge device, a separation tank 90, a water inlet device 20, a three-way valve, a detection device 40, a heating device 50, a heat preservation device 60, an oil content detector 70, and multiple temperature sensors 80.

[0039] The bottom of the separator 90 is designed as a hemispherical, inverted truncated pyramid, or inverted frustum structure. Oily wastewater gradually separates into an oil layer, a water layer, and a sludge layer from top to bottom through settling within the separator 90. The sludge layer is discharged from the bottom of the separator 90. During this process, the sludge accumulates along the inner wall of the bottom of the separator 90 and is then completely discharged through the discharge port to prevent it from condensing on the inner wall of the separator 90. The separator 90 can be made of stainless steel, carbon steel, ceramic, or cement.

[0040] An automatic sludge discharge device is installed on the separation tank 90 to automatically discharge the sludge that settles at the bottom of the separation tank 90. ​​The automatic sludge discharge device includes a discharge device 1, a stirring device 2, a pressure sensor, and a controller (not shown).

[0041] The discharge device 1 includes a sewage pump, a sewage pipe, and an electric valve. One end of the sewage pipe is connected to the bottom of the separator 90, and the other end is connected to the sewage pump. The electric valve is installed on the sewage pipe and is used to control the on / off state of the sewage pipe.

[0042] The stirring device 2 includes a motor 21, a rotating shaft 22, multiple support rods 23, multiple stirring rods 24, a hollow shaft 25, and at least one scraper 26. The rotating shaft 22 is coaxially arranged with the bottom of the separation tank 90. ​​The top end of the rotating shaft 22 passes through the top surface of the separation tank 90 and is fixedly connected to the output end of the motor 21. Multiple support rods 23 are arranged in a horizontal ring at the bottom end of the rotating shaft 22. The ends of the support rods 23 away from the rotating shaft 22 are inclined downwards. Multiple stirring rods 24 are arranged in an array on each support rod 23. Each stirring rod 24 is vertically downwards. The stirring rods 24 have an inverted pyramidal or inverted conical structure. The bottom ends of the multiple stirring rods 24 on the same support rod 23 are collinear, and the distance between the bottom end of each stirring rod 24 and the inner wall of the separation tank 90 is equal.

[0043] The starting motor 21 drives the rotating shaft 22 to rotate counterclockwise or clockwise, which in turn drives all the support rods 23 and stirring rods 24 to rotate synchronously, stirring and mixing the oily wastewater at the bottom of the separation tank 90. ​​The output speed of the motor 21 does not exceed a preset speed to minimize interference with the oily wastewater at the top of the separation tank 90 and prevent the separated oil and water layers from mixing again. The stirring rods 24 agitate the sludge layer formed after the oily wastewater stratifies, ensuring thorough mixing between the sludge layer and part of the water layer, preventing clumping and blockages, and allowing for smooth discharge of the sludge layer. Simultaneously, the surface of the mixed sludge layer tends to be flat, facilitating the measurement of sludge layer depth and avoiding inaccurate measurements due to sludge adhesion to the inner wall of the separation tank or an uneven sludge layer surface.

[0044] In this embodiment, the angle between the support rod 23 and the rotating shaft 22 is between 45° and 75°, and the bottom end of the support rod 23 is not higher than a preset depth h0, while the top end of the support rod 23 is higher than the depth h0. The spacing between adjacent stirring rods 24 is 5 to 7 cm. Of course, in other embodiments, the angle between the support rod 23 and the rotating shaft 22 can be larger or smaller, and the spacing between the stirring rods 24 can also be larger or smaller.

[0045] One side of the scraper 26 is fixedly connected to the end of the support rod 23 away from the rotating shaft 22. The other side of the scraper 26 is in contact with the bottom inner wall of the separation tank 90. ​​While stirring the sludge layer, the scraper 26 can also scrape off the sludge adhering to the inner wall of the separation tank to prevent the sludge from clumping together, occupying the effective volume of the separation tank, or even producing odors.

[0046] A hollow shaft 25 is coaxially mounted on the outside of the rotating shaft 22 and rotatably connected to the rotating shaft 22. The hollow shaft 25 is fixedly connected to the separation tank 90. ​​By setting the hollow shaft 25, the water and oil layers above the bottom of the hollow shaft 25 are not directly stirred during sludge stirring. Due to the low rotation speed of the sludge stirring, there is almost no disturbance to the upper water and oil layers, thus maintaining the separation efficiency of the water and oil layers.

[0047] The pressure sensor is fixedly mounted on the support rod 23 or the stirring rod 24, and is used to measure the resistance value F of the oily wastewater to the stirring device 2 at different heights during the operation of the stirring device 2. n In this embodiment, five pressure sensors are installed on different stirring rods 24, respectively positioned at distances of 40cm, 45cm, 50cm, 55cm, and 60cm from the bottom of the tank. One pressure sensor is installed on one of the support rods 23, 70cm from the bottom of the separation tank. When stirring oily wastewater, the stirring rods 24 experience resistance from the oily wastewater. The resistance from the sludge layer to the stirring rods 24 is significantly greater than the resistance from the water or oil layer. Based on the resistance value experienced by the stirring rods 24 during stirring, it can be determined whether the oily wastewater at the same height as the pressure sensor is a sludge layer, an oil layer, or a water layer.

[0048] The controller is used for: 1. According to a preset period T c1 The stirring device 2 is operated to ensure that the sludge at the bottom of the separation tank 90 is mixed evenly, while the resistance value F measured by each pressure sensor is collected. n Since the settling process of oily wastewater is uncontrollable and the amount of sludge separated is difficult to determine, real-time or periodic sludge discharge is clearly insufficient to meet discharge requirements. To maintain sludge fluidity and prevent it from clumping together, the sludge can be stirred periodically.

[0049] II. Based on the measured resistance value F n The corresponding sludge moisture content is looked up in a pre-stored conversion table. The conversion table represents the mapping relationship between the resistance value experienced by the mixing device and the sludge moisture content. Since the resistance of sludge to the mixing device 2 is significantly greater than that of water or oil, the sludge moisture content at different heights of the oily wastewater can be obtained by collecting the resistance values ​​experienced by the mixing device 2 at different heights during the mixing process. The conversion table can be obtained through preliminary experiments. The conversion table can be obtained as follows: Set up sludge with different moisture contents, such as starting from 70% and increasing by 1% each time until the moisture content reaches 95%. Place the mixing device 2 sequentially in sludge with different moisture contents, mix at a preset mixing speed, and collect the corresponding resistance values. Establish a conversion table based on the moisture content and its corresponding resistance value.

[0050] 3. Calculate the sludge depth based on the sludge moisture content at different heights, and determine if the sludge depth is higher than a preset depth h0. If so, activate the discharge device to discharge the sludge from the separation tank. Set the oily wastewater with a moisture content not exceeding 80% as the sludge layer; then the depth of the sludge layer is the depth of the oily wastewater with a moisture content of 80%. Since the density of sludge is greater than that of water, and the higher the moisture content of the sludge, the lower its density. Assume that the sludge moisture content at multiple detection points not higher than height h1 is all below 80%, and the sludge moisture content at detection points above h1 is all greater than 80%. Let the sludge moisture content at h1 be ω. w1 The sludge moisture content at the previous detection point h2, which is higher than h1, is ω. w2 The actual depth h of the sludge can then be expressed as:

[0051] h=h1+∣ω w1 -80%∣(h2-h1) / (ω w2 -ω w1 ).

[0052] For example, if the sludge depth is 50cm and the water content is 79%, and the sludge depth is 55cm and the water content is 83%, then the sludge depth is h = 50 + |79% - 80%| (55 - 50) / (83% - 79%) = 51.25cm.

[0053] The automatic sludge discharge device in this embodiment, by periodically stirring the sludge at the bottom of the separation tank, not only mixes the sludge layer evenly, preventing coagulation and adhesion that could cause blockages, but also more accurately measures the depth of the sludge layer. This allows for the complete discharge of the bottom sludge when it reaches a preset depth. Compared to manual sludge discharge, this automatic sludge discharge device can discharge sludge promptly and quickly, preventing sludge from clumping, clogging the separation tank, and producing odors. Compared to timed sludge discharge, this automatic sludge discharge device offers more precise discharge, avoids the discharge of oil and water, prevents secondary pollution to the environment, and is also more energy-efficient, reducing operating costs.

[0054] The inlet device 20 is connected to the separator 90 and is used to introduce oily wastewater into the separator 90. The inlet device 20 includes a submersible pump, an inlet pipe, and an electric valve. The submersible pump is installed in a sump for storing the oily wastewater. The inlet end of the inlet pipe is connected to the submersible pump, and the outlet end of the inlet pipe is connected to the separator 90. The electric valve is installed on the inlet pipe and is used to control the on / off state of the inlet pipe. The connection between the inlet pipe and the separator 90 is located in the middle of the separator 90, above a preset discharge height.

[0055] Oily wastewater stratifies within the separator tank, gradually forming an oil layer, a water layer, and a sludge layer from top to bottom. During this process, an unseparated oil-water mixture layer exists between the oil and water layers. Once the sludge layer reaches the preset discharge depth (e.g., 1 / 3 of the separator tank height) and is discharged, the oily wastewater level in the separator tank drops, allowing for the replenishment of oily wastewater. Ideally, the replenished oily wastewater should be placed within the oil-water mixture layer to avoid interfering with the already separated oil and water layers. Because the rate of solid-liquid separation (separation of the sludge layer from the liquid oil and water layers) in oily wastewater is greater than the rate of oil-water separation, timely sludge discharge and replenishment of oily wastewater effectively utilize the separator tank's volume and improve the three-phase separation efficiency of the oily wastewater.

[0056] The three-way valve includes one inlet and two outlets. The inlet connects to the outlet of the automatic sludge discharge device. One outlet is used for sludge or water discharge, and the other is used for oil discharge. The oil separated from the oily wastewater is recycled, reducing environmental pollution, saving energy, and turning waste into treasure. Separated sludge or wastewater that meets discharge standards can be discharged directly. When used in conjunction with an oil content detector 70, the three-way valve can distinguish between the water and oil layers based on oil content during discharge, achieving oil-water separation of oily wastewater.

[0057] Please combine Figure 3 , it is Figure 2 A cross-sectional structural diagram of the detection device 40 is shown. The detection device 40 includes a housing 401 and a positioner 402. The housing 401 is a hollow sphere. The positioner 402 is fixedly connected to the center of the housing 401 and is used to measure the position of the housing 401 in real time. The overall density of the detection device 40 is greater than the density of oil and less than the density of water. The detection device 40 is placed inside the separation tank 90 to measure its own real-time position. Oily wastewater stratifies in the separation tank 90. ​​Because the overall density of the detection device 40 is greater than the density of oil and less than the density of water, the detection device 40 will be suspended in the oil-water mixture layer. As oil-water separation proceeds, the oil-water mixture layer gradually decreases, while the oil and water layers gradually increase, and the position of the oil-water mixture layer also changes continuously. Therefore, by measuring the position change of the detection device 40, the progress of oil-water separation can be determined. When the position of the detection device 40 is within a preset period T... c2 If no changes occur within the oily wastewater, it can be considered that the oily wastewater has been completely separated into layers, and the oily wastewater can be discharged or recycled in layers.

[0058] A heating device 50 is installed at the connection between the water inlet device 20 and the separation tank 90 to heat the oily wastewater entering the water. The heating device 50 can be an infrared heater, which not only provides non-contact heating, preventing oily wastewater from adhering to it, but also provides uniform heating and rapid temperature rise, ensuring that the oily wastewater enters the separation tank 90 within a preset temperature range, thus keeping the grease in the oily wastewater in the liquid phase. Of course, in other embodiments, the heating device 50 can also be a carbon fiber heating plate, etc.

[0059] An insulation device 60 is installed on the separation tank 90 to insulate the oily wastewater inside. The insulation device can be an energy-efficient insulation material board, such as a vacuum insulation board, polyurethane board, fiberglass board, or inorganic polymer insulation board, or it can be an electric heating board, such as a carbon fiber heating board, as long as it can achieve low-energy insulation of the oily wastewater. The insulation device 60 should cover at least two-thirds of the top area of ​​the separation tank 90 to prevent grease from solidifying. Separating the heating process from the insulation process not only improves heating efficiency and maintains the high efficiency of the oil-water separation process, but also eliminates the need for overall heating of the oily wastewater inside the separation tank 90, reducing overall energy consumption and operating costs.

[0060] The oil content analyzer 70 is used to detect the oil content ω at the outlet of the automatic sludge discharge device. o1 By detecting the oil content ω o1 It can distinguish between oil and water layers when discharging oily wastewater, and then selectively recover the oil layer.

[0061] Temperature sensor 80 is used to measure the real-time temperature T1 of the oily wastewater entering the tank and the average temperature T2 of the oily wastewater in the separator 90. Some of the grease in the oily wastewater is in the solid phase at room temperature (25°C). The oily wastewater is preheated, and its temperature is measured in real time to keep the grease in the oily wastewater melted into a liquid phase.

[0062] The controller of the automatic sludge discharge device can also be used as a control device for a three-phase separation device. Accordingly, the controller is also used to: 1. Determine whether the temperature T1 and the average temperature T2 exceed a preset temperature range; if so, adjust the output power of the heating device 50 or the heat preservation device 60 until the temperature T1 and the average temperature T2 are within the temperature range. In this embodiment, the preset temperature range is 40–45°C. Of course, in other embodiments, the preset temperature range can be higher or lower.

[0063] II. The detection device 40 operates within a preset period T. c2 If there is no change in internal height, then activate the emission device 1 and the oil content detector 70, and determine the oil content ω. o1 Is the oil content ω higher than a preset level? sIf yes, then drain the oil; otherwise, drain the sludge or water.

[0064] The three-phase separation equipment in this embodiment preheats the oily wastewater, melting the solid oil in the wastewater into liquid oil, preventing sludge and oil from clumping together and becoming difficult to separate. Simultaneously, an automatic sludge discharge device promptly removes sludge settled at the bottom of the separation tank and replenishes the oily wastewater, fully utilizing the effective volume of the separation tank and improving the separation efficiency. Finally, by measuring the oil content of the discharged oily wastewater in real time, the water layer and oil layer are accurately distinguished, and the oil layer is recycled, reducing secondary pollution, saving energy, and lowering treatment costs.

[0065] Please combine Figure 4 This is a flowchart of the three-phase separation method for oily wastewater according to this embodiment. To facilitate standardized operation of the aforementioned three-phase separation equipment and achieve efficient treatment of oily wastewater, this embodiment also provides a three-phase separation method for oily wastewater, which includes the following steps:

[0066] S1: After heating the oily wastewater to a preset temperature range, it is introduced into a separation tank until the liquid level of the oily wastewater reaches a preset height. The oily wastewater in the separation tank is kept at a constant temperature to ensure that the average temperature of the oily wastewater within the tank remains within the set temperature range. Through static sedimentation, the oily wastewater in the separation tank is separated into an oil layer, a water layer, and a sludge layer from top to bottom. Heating the oily wastewater to the preset temperature range melts the grease in the wastewater into a liquid phase, preventing the grease and sludge from coagulating into clumps that are difficult to separate.

[0067] S2: Based on a preset period T c1 Oily wastewater below a preset height is stirred to ensure uniform mixing of the sludge layer. Simultaneously, the resistance value F of the oily wastewater at different heights to the stirring device is collected during the stirring process. n Then, the corresponding sludge moisture content is looked up in a conversion table. The conversion table represents the mapping relationship between the resistance value of the agitator and the sludge moisture content. After separation, the sludge layer in oily wastewater settles at the bottom of the separation tank. Timely agitation of the sludge can prevent it from clumping together, thus preventing sludge blockage of the discharge pipe, maintaining sludge flowability, and facilitating sludge discharge. The surface of the agitated sludge layer tends to be flat, making it easier to measure the sludge layer depth. At the same time, the resistance of a uniformly agitated sludge layer or water layer to the agitator tends to be stable, making it easier to analyze the moisture content of the sludge layer.

[0068] S3: Calculate the sludge depth based on the water content at different heights. When the sludge depth h is greater than a preset depth h... s At this time, the sludge is discharged, and oily wastewater is added to the separation tank until the oily wastewater level reaches a preset height. The sludge depth h can be calculated using the following formula:

[0069] h=h1+∣ω w1 -80%∣(h2-h1) / (ω w2 -ω w1 ).

[0070] Where h1 is the height of the highest measuring point where the water content meets the preset range, ω w1 Let h1 be the sludge moisture content, h2 be the height of the previous detection point above h1, and ω be the sludge moisture content. w2 The sludge moisture content at point h2 is given.

[0071] When the sludge reaches a preset depth, all the sludge can be discharged. The amount of sludge discharged each time can be a preset discharge volume, such as the preset discharge volume calculated based on the preset depth and the size of the separation tank 90, or the actual volume of oily wastewater calculated based on the actual depth of the sludge.

[0072] S4: When the oily wastewater in the separator tank has completely separated into layers, discharge the oily wastewater from the bottom of the separator tank, and simultaneously measure the oil content ω of the oily wastewater at the bottom of the separator tank. o1 When the oil content ω o1 Oil content ω below a preset level s In some cases, the water and sludge layers in the oily wastewater are discharged directly; otherwise, the oil layer in the oily wastewater is recovered. Since the oil and water layers are completely separated, they can be distinguished by observing their colors during discharge, allowing for manual control of the discharge. Alternatively, the oil content can be monitored in real time to differentiate between the oil and water layers, preventing the discharge of the oil layer and avoiding secondary pollution.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0074] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An automatic sludge discharge device for oily wastewater, used to automatically discharge sludge from a separation tank in a three-phase separation process of oily wastewater; the automatic sludge discharge device includes a discharge device connected to the bottom end of the separation tank for discharging sludge from the separation tank; characterized in that, The automatic sludge removal device also includes: A stirring device includes a motor, a rotating shaft, multiple support rods, and multiple stirring rods; the rotating shaft is coaxially arranged with the bottom of the separation tank; the top end of the rotating shaft passes through the separation tank and is fixedly connected to the output end of the motor; multiple support rods are arranged in a horizontal ring at the bottom end of the rotating shaft; the ends of the support rods away from the rotating shaft are inclined downwards; multiple stirring rods are arranged in an array on each support rod; each stirring rod is vertically downwards. A water inlet device, which is connected to the separation tank, is used to introduce oily wastewater into the separation tank; An oil content detector and multiple temperature sensors are used, wherein the oil content detector is used to detect the oil content ω at the outlet of the automatic sludge discharge device. o1 The temperature sensor is used to measure the real-time temperature T1 of the oily wastewater in the water inlet device and the average temperature T2 of the oily wastewater in the separation tank. Multiple pressure sensors, fixedly mounted on the support rod or the stirring rod, are used to measure the resistance value F of oily wastewater to the stirring device at different heights during operation of the stirring device. n ;as well as The controller is used to:

1. Based on a preset period T c1 The stirring device is controlled to ensure uniform mixing of the sludge at the bottom of the separation tank, while the resistance value F measured by each pressure sensor is collected. n 2. Based on the measured resistance value F n The corresponding sludge moisture content is looked up in a pre-stored conversion table; the conversion table represents the mapping relationship between the resistance value of the stirring device and the sludge moisture content; third, the sludge depth is calculated based on the sludge moisture content at different heights, and it is determined whether the sludge depth is higher than a preset depth h0. If so, the discharge device is activated to discharge the sludge in the separation tank and replenish the separation tank with oily wastewater until the liquid level of the oily wastewater reaches a preset height; fourth, when the oily wastewater in the separation tank is completely separated, the oily wastewater is discharged from the bottom of the separation tank, and the oil content ω of the oily wastewater at the bottom of the separation tank is measured. o1 And in oil content ω o1 Oil content ω below a preset level s If necessary, the water and sludge layers in the oily wastewater will be discharged directly; otherwise, the oil layer in the oily wastewater will be recycled.

2. The automatic sludge removal device for oily wastewater according to claim 1, characterized in that, The stirring rod has an inverted pyramidal or inverted conical structure.

3. The automatic sludge removal device for oily wastewater according to claim 1, characterized in that, A scraper is fixedly connected to at least one of the support rods; one side of the scraper is fixedly connected to the end of the support rod away from the rotation axis; the other side of the scraper is in contact with the bottom inner wall of the separation tank.

4. The automatic sludge removal device for oily wastewater according to claim 1, characterized in that, The stirring device also includes a hollow shaft; the hollow shaft is coaxially disposed outside the rotating shaft and rotatably connected to the rotating shaft; the hollow shaft is fixedly connected to the separation tank.

5. The automatic sludge removal device for oily wastewater according to claim 1, characterized in that, The discharge device includes a sewage pump, a sewage pipe, and an electric valve; one end of the sewage pipe is connected to the bottom of the separation tank, and the other end of the sewage pipe is connected to the sewage pump; the electric valve is installed on the sewage pipe and is used to control the on / off state of the sewage pipe.

6. A three-phase separation device for oily wastewater, comprising a separation tank, wherein the bottom of the separation tank is a hemispherical, inverted frustum, or inverted truncated cone structure, and the three-phase separation device further comprising: Automatic sludge removal device for oily wastewater as described in any one of claims 1 to 5; The three-way valve includes one input end and two output ends; the input end is connected to the outlet end of the automatic sludge discharge device; one of the output ends is used for sludge discharge or drainage, and the other output end is used for oil discharge; as well as The detection device includes a housing and a locator; the housing is a hollow sphere; the locator is fixedly connected to the center of the sphere of the housing for real-time measurement of the position of the housing; the overall density of the detection device is greater than the density of oil and less than the density of water; the detection device is placed inside the separation tank for measuring its own real-time position.

7. The three-phase separation device for oily wastewater according to claim 6, characterized in that, The water inlet device includes a submersible pump, an inlet pipe, and an electric valve 2; the submersible pump is installed in a sump for storing oily wastewater; the inlet end of the inlet pipe is connected to the submersible pump, and the outlet end of the inlet pipe is connected to the separation tank; the electric valve 2 is installed on the inlet pipe and is used to control the on / off state of the inlet pipe.

8. The three-phase separation device for oily wastewater according to claim 6, characterized in that, The three-phase separation equipment also includes a heating device and a heat preservation device; the heating device is installed at the connection between the water inlet device and the separation tank, and is used to heat the oily wastewater entering the water; the heat preservation device is installed on the separation tank, and is used to keep the oily wastewater in the separation tank warm.

9. The three-phase separation device for oily wastewater according to claim 7 or 8, characterized in that, The controller of the automatic sludge removal device is also used for:

1. determining whether the temperature T1 and the average temperature T2 exceed a preset temperature range; if so, adjusting the output power of the heating device or the heat preservation device until the temperature T1 and the average temperature T2 are within the temperature range.

10. A method for three-phase separation of oily wastewater, applied to the three-phase separation equipment for oily wastewater as described in any one of claims 6 to 9, characterized in that, The three-phase separation method includes the following steps: S1: After heating the oily wastewater to a preset temperature range, it is introduced into a separation tank until the liquid level of the oily wastewater reaches a preset height; the oily wastewater in the separation tank is kept warm so that the average temperature of the oily wastewater in the separation tank is within the preset temperature range; the oily wastewater in the separation tank is separated into an oil layer, a water layer and a sludge layer from top to bottom by static sedimentation. S2: Based on a preset period T c1 The oily wastewater below a preset height is stirred to ensure uniform mixing of the sludge layer; simultaneously, the resistance value F of the oily wastewater at different heights to the stirring device is collected during the stirring process. n Then, the corresponding sludge moisture content is looked up in a conversion table; the conversion table represents the mapping relationship between the resistance value of the stirring device and the sludge moisture content; S3: Calculate the sludge depth based on the water content at different heights. When the sludge depth h is greater than a preset depth h... s At that time, the sludge is discharged, and oily wastewater is added to the separation tank until the level of the oily wastewater reaches a preset height; S4: When the oily wastewater in the separation tank has completely separated into layers, the oily wastewater is discharged from the bottom of the separation tank, and the oil content ω of the oily wastewater at the bottom of the separation tank is measured. o1 When the oil content ω o1 Oil content ω below a preset level s If necessary, the water and sludge layers in the oily wastewater will be discharged directly; otherwise, the oil layer in the oily wastewater will be recycled.

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