CN115745079A - Automatic sludge discharge device for oily sewage, three-phase separation equipment and method - Google Patents

Abstract

The invention relates to an automatic sludge discharge device, three-phase separation equipment and a method for oily sewage. The automatic sludge discharging device comprises a discharging device, a stirring device, a pressure sensor and a controller. The discharge device is communicated with the bottom end of the separation tank. The stirring device comprises a motor, a rotating shaft, a plurality of support rods and a plurality of stirring rods. The top end of the rotating shaft penetrates through the separating tank and is fixedly connected with the output end of the motor. A plurality of annular arrays of support rods are at the bottom end of the rotating shaft. A plurality of stirring rods are arranged on each support rod in an array mode. The pressure sensor is fixedly arranged on the support rod or the stirring rod. The controller is used for controlling the starting and stopping state of the discharging device according to the pressure collected by the pressure sensor. The invention can avoid the blockage caused by the coagulation and adhesion of the sludge by regularly stirring the sludge, can more accurately measure the depth of a sludge layer, discharges the sludge at the bottom at one time, and has the advantages of more accurate discharge, secondary pollution prevention and more energy saving.

Description

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

technical field

The invention relates to an automatic sludge discharge device, in particular to an automatic sludge discharge device for oily sewage, a three-phase separation device for oily sewage, and a three-phase separation method for oily sewage.

Background technique

In the three-phase separation of oily sewage, it is generally divided into two steps: solid-liquid separation and oil-water separation. These two steps can also be carried out simultaneously, as a whole step. Among them, since the density of solid impurities (sludge) in oily sewage is significantly greater than that of water, and the density of oil is closer to that of water, the rate of solid-liquid separation is generally greater than the efficiency of oil-water separation. The denser solid impurities accumulate at the bottom of the separation equipment after standing and settling. If the accumulated sludge is not discharged for a long time, the sludge layer will continue to rise over time, occupying the effective volume of the separation equipment, reducing the hydraulic retention time, and failing to meet the processing requirements of static layered separation. At the same time, if the residue is not discharged for a long time, it will also affect the quality of the effluent water, increase the generation of odor, block the flow channel of the waste water, and the waste residue may be wrapped with the waste oil to form a solid mass.

Existing sludge discharges can be controlled manually or periodically. Due to the uncertainty of manual control, it is easy to cause untimely discharge, block the discharge device, and even damage the separation equipment. With regular discharge, it is also difficult to determine the time of each discharge (or the amount of sludge) due to the inconsistency of the time of each sludge settlement, and there may be problems such as incomplete discharge and secondary pollution caused by oil and water discharge.

Contents of the invention

Based on this, it is necessary to provide an automatic sludge discharge device for oily sewage, three Phase separation apparatus and method.

The invention is realized through the following technical solutions: an automatic sludge discharge device for oily sewage includes a discharge device, a stirring device, a pressure sensor and a controller.

The discharge device communicates with the bottom end of the separation tank and is used to discharge the sludge in the separation tank. The stirring device includes a motor, a rotating shaft, a plurality of support rods and a plurality of stirring rods. The rotating shaft is arranged coaxially with the bottom of the separation tank. The top of the rotating shaft passes through the separation tank and is fixedly connected with the output end of the motor. A plurality of support rods are arrayed circularly along the horizontal direction at the bottom end of the rotating shaft. One end of the support rod away from the rotating shaft is arranged obliquely downward. A plurality of stirring rods are arrayed on each support rod. Each stirring rod is arranged vertically downward. The pressure sensor is fixedly installed on the support rod or the stirring rod, and is used to measure the resistance value F _n of the oily sewage at different heights to the stirring device when the stirring device is running.

The controller is used to: 1. Control the operation of the stirring device according to a preset period T _c1 so as to make the sludge at the bottom of the separation tank evenly mixed, and at the same time collect the resistance value F _n measured by each pressure sensor. 2. According to the measured resistance value _Fn, look up the corresponding sludge moisture content in a pre-stored conversion table. The conversion table represents the mapping relationship between the resistance value of the stirring device and the moisture content of the sludge. 3. Calculate the sludge depth according to the moisture content of the sludge at different heights, and judge whether the sludge depth is higher than a preset depth h ₀ , and if so, activate the discharge device to discharge the sludge in the separation tank.

The above-mentioned automatic sludge discharge device can not only mix the sludge layer uniformly by regularly stirring the sludge at the bottom of the separation tank, avoid clogging caused by coagulation and adhesion, but also can more accurately measure the depth of the sludge layer, so that the sludge layer When the preset depth is reached, the bottom sludge is discharged at one time. Compared with manual sludge discharge, the automatic sludge discharge device can discharge the sludge in a timely and rapid manner, preventing the sludge from agglomerating, clogging the separation tank, and generating peculiar smell. Compared with regular sludge discharge, the above-mentioned automatic sludge discharge device discharges more accurately, can avoid discharge of oil and water, avoids secondary pollution to the environment, and is more energy-efficient and reduces operating costs.

In one of the embodiments, the stirring rod is an inverted pyramid or an inverted cone.

In one of the embodiments, 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 attached to the bottom inner wall of the separation tank.

In one of the embodiments, the hollow shaft is arranged coaxially outside the rotating shaft and is rotatably connected with the rotating shaft. The hollow shaft is fixedly connected with the separation tank.

In one of the embodiments, the discharge device includes a sewage pump, a sewage pipe and an electric valve. One end of the sewage pipe communicates with the bottom of the separation tank, and the other end of the sewage pipe communicates with the sewage pump. The electric valve is installed on the sewage pipe to control the on-off state of the sewage pipe.

The present invention also provides a three-phase separation device for oily sewage. The three-phase separation device includes 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, and an oil content detector. and multiple temperature sensors.

The bottom of the separation tank is a hemispherical or chamfered truss or rounded truss structure. The water inlet device communicates with the separation tank and is used for introducing oily sewage into the separation tank. A three-way valve includes an input and two outputs. The input end communicates with the outlet end of the automatic mud discharge device. One of the outputs is used for sludge or water discharge, and the other is used for oil discharge. The detection device includes a housing and a locator. The shell is a hollow sphere. The locator is fixedly connected to the spherical center of the shell, and is used for measuring the position of the shell in real time. The overall density of the detection device is greater than that of oil and less than that of water. The detection device is placed in the separation tank and is used to measure its own real-time position.

In one of the embodiments, the water inlet device includes a submersible sewage pump, a water inlet pipe and an electric valve II. Submersible sewage pumps are installed in sumps used to store oily sewage. The inlet end of the water inlet pipe is connected with the submersible sewage pump, and the outlet end of the water inlet pipe is connected with the separation tank. The second electric valve is installed on the water inlet pipe and is used to control the on-off state of the water inlet pipe.

In one of the embodiments, the heating device is installed at the connection between the water inlet device and the separation tank, and is used for heating the oily sewage in the water. The heat preservation device is installed on the separation tank, and is used for heat preservation of the oily sewage in the separation tank.

In one of the embodiments, the oil content detector is used to detect the oil content ω _o1 at the outlet end of the automatic sludge discharge device. The temperature sensor is used to measure the real-time temperature T ₁ of the oily sewage entering the water and the average temperature T ₂ of the oily sewage in the separation tank.

The controller of the automatic mud discharge device is also used for: 1. To judge whether the temperature _T1 and the average temperature _T2 exceed a preset temperature range, and then adjust the output power of the heating device or the heat preservation device until the temperature _T1 and the average temperature _T2 is in the temperature range. 2. Judging whether the detection device has no height change within a preset period T _c2 , if so, start the discharge device of the automatic mud discharge device and the oil content detector, and judge whether the oil content ω _o1 is higher than a preset oil content ω _s , if yes, carry out oil discharge, otherwise, carry out mud discharge or drainage.

The present invention also provides a three-phase separation method for oily sewage, the three-phase separation method comprising the following steps:

S1: The oily sewage is heated to a preset temperature range and then introduced into a separation tank until the liquid level of the oily sewage reaches a preset height. The oily sewage in the separation tank is insulated so that the average temperature of the oily sewage in the separation tank is within the temperature range. The oily sewage in the separation tank is divided into oil layer, water layer and sludge layer from top to bottom by static sedimentation.

S2: Stir the oily sewage below a preset height according to a preset period _Tc1 , so that the sludge layer is evenly mixed. At the same time, the resistance value F _n of the oily sewage at different heights to the stirring device is collected during the stirring process, and then the corresponding sludge moisture content is queried in a conversion table. The conversion table represents the mapping relationship between the resistance value of the stirring device and the moisture content of the sludge.

S3: Calculate the depth of the sludge according to the water content at different heights. When the depth h of the sludge is greater than a preset depth h _s , discharge the sludge and add oily sewage to the separation tank until the liquid level of the oily sewage reaches a preset height.

S4: When the oily sewage in the separation tank is completely stratified, discharge the oily sewage from the bottom of the separation tank, and measure the oil content ω _o1 of the oily sewage at the bottom of the separation tank at the same time, when the oil content ω _o1 is lower than a preset oil content When measuring ω _s , the water layer and sludge layer in the oily sewage are discharged directly, otherwise the oil layer in the oily sewage is recovered.

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

1. The automatic sludge discharge device of the present invention can not only mix the sludge layer uniformly by regularly stirring the sludge at the bottom of the separation tank, avoid clogging caused by coagulation and adhesion, but also can more accurately measure the depth of the sludge layer, thereby When the sludge layer reaches the preset depth, the bottom sludge is discharged at one time. Compared with manual discharge of sludge, the automatic sludge discharge device of the present invention can discharge the sludge in a timely and rapid manner, preventing the sludge from agglomerating into blocks, blocking the separation tank, and generating peculiar smell. Compared with regular sludge discharge, the automatic sludge discharge device of the present invention discharges more accurately, can avoid discharge of oil and water, avoids secondary pollution to the environment, and is more energy-efficient and reduces operating costs.

2. The three-phase separation equipment of the present invention melts the solid-phase grease in the oily sewage into liquid-phase grease by preheating the oily sewage, preventing the sludge and grease from agglomerating into blocks that are difficult to separate, and at the same time adopts an automatic sludge discharge device to reduce the sedimentation The sludge at the bottom of the separation tank is discharged in time, and the oily sewage is supplemented to make full use of the effective volume of the separation tank and improve the separation efficiency of the oily sewage. Finally, by measuring the oil content of the discharged oily sewage in real time, the water layer and the oil layer can be accurately distinguished, and the oil layer can be recycled, which not only reduces secondary pollution, but also saves energy and reduces treatment costs.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the three-phase separation equipment that is used for oily sewage in embodiment 1 of the present invention;

Fig. 2 is the sectional structure schematic diagram of three-phase separation equipment in Fig. 1;

Fig. 3 is a schematic cross-sectional structure diagram of the detection device in Fig. 2;

Fig. 4 is a flow chart of the three-phase separation method for oily sewage according to Embodiment 1 of the present invention.

Description of main component symbols

The labels in the figure are: 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. Housing; 402. Locator; 50. Heating device; 60. Heat preservation device; 90. Separation tank.

The above description of the symbols of the main components will further describe the present invention in detail in conjunction with the accompanying drawings and specific embodiments.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that when a component is said to be "mounted on" another component, it can be directly on the other component or there can also be an intervening component. When a component is said to be "set on" another component, it may be set directly on the other component or there may be an intervening component at the same time. When a component is said to be "fixed" to another component, it may be directly fixed to the other component or there may be an intervening component at the same time.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Example 1

Please refer to Figure 1 and Figure 2, Figure 1 is a three-dimensional structural schematic diagram of the three-phase separation equipment for oily sewage in this embodiment; Figure 2 is a cross-sectional structural schematic diagram of the three-phase separation equipment in Figure 1. The three-phase separation equipment 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 a plurality of temperature sensors 80 .

The bottom of the separation tank 90 is set in a hemispherical or chamfered frustum or rounded frustum structure. The oily sewage in the separation tank 90 is gradually divided into an oil layer, a water layer and a sludge layer from top to bottom by standing and settling. The sludge layer is discharged from the bottom of the separation tank 90. During this process, the sludge gathers inward along the bottom inner wall of the separation tank 90, and then all of it is discharged through the discharge port to avoid condensation on the inner wall of the separation tank 90. Separation tank 90 can adopt stainless steel tank body, also can adopt tank body such as carbon steel, pottery or cement.

The automatic sludge discharge device is installed on the separation tank 90 and is used to automatically discharge the sludge settled at the bottom of the separation tank 90 . The automatic mud discharge device includes a discharge device 1, a stirring device 2, a pressure sensor and a controller (not shown).

The discharge device 1 includes a sewage pump, a sewage pipe and an electric valve one. One end of the blowdown pipe communicates with the bottom of the separation tank 90, and the other end communicates with the blowdown pump. The electric valve is installed on the sewage pipe to control the on-off state of the sewage pipe.

The stirring device 2 includes a motor 21 , a rotating shaft 22 , a plurality of support rods 23 , a plurality of stirring rods 24 , a hollow shaft 25 and at least one scraper 26 . The rotation shaft 22 is provided coaxially 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 with the output end of the motor 21 . A plurality of support rods 23 are arranged in a circular array along the horizontal direction at the bottom end of the rotating shaft 22 . One end of the support rod 23 away from the rotating shaft 22 is arranged obliquely downward. A plurality of stirring rods 24 are arranged in an array on each support rod 23 . Each stirring rod 24 is arranged vertically downward. The stirring rod 24 is an inverted pyramid or an inverted cone structure. The bottom ends of 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.

The starter motor 21 drives the rotating shaft 22 to rotate counterclockwise or clockwise, and then drives all the support rods 23 and the stirring rods 24 to rotate synchronously to stir and mix the oily sewage at the bottom of the separation tank 90 . Wherein, the output rotational speed of the motor 21 is not greater than a preset rotational speed, so as to reduce interference to the oily sewage at the top of the separation tank 90 and prevent the separated oil layer and water layer from mixing again. Stirring the sludge layer formed after the oily sewage is layered by a plurality of stirring rods 24 can not only fully mix the sludge layer with part of the water layer, but also avoid clogging caused by agglomeration, so that the sludge layer can be discharged smoothly, and at the same time , the surface of the sludge layer after mixing tends to be flat, which is convenient for measuring the depth of the sludge layer, and avoids the inaccurate measurement of the actual depth of the sludge layer due to the sludge adhering to the inner wall of the separation tank or the uneven surface of the sludge layer.

In this embodiment, the angle between the support rod 23 and the rotation axis 22 is between 45° and 75°, and the bottom end of the support rod 23 is not higher than a preset depth h ₀ , and the top end of the support rod 23 above depth h ₀ . The distance between adjacent stirring rods 24 is 5-7 cm. Certainly, in other embodiments, the included angle between the support rod 23 and the rotating shaft 22 may be larger or smaller, and the distance between the stirring rods 24 may also be larger or smaller.

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 attached to the bottom inner wall of the separation tank 90 . While stirring the sludge layer, the scraper 26 can also be used to scrape off the sludge adhering to the inner wall of the separation tank, so as to prevent the sludge from agglomerating into blocks, occupying the effective volume of the separation tank, and even producing peculiar smell.

The hollow shaft 25 is coaxially arranged outside the rotating shaft 22 and is rotatably connected with the rotating shaft 22 . The hollow shaft 25 is fixedly connected with the separation tank 90 . By setting the hollow shaft 25, when the sludge is stirred, the water layer and the oil layer higher than the bottom of the hollow shaft 25 are not directly stirred. Due to the low rotation speed of the stirred sludge, there is almost no disturbance to the upper water layer and oil layer, and the separation efficiency of the water layer and the oil layer can be maintained.

The pressure sensor is fixedly installed on the support rod 23 or the stirring rod 24, and is used to measure the resistance value _Fn of the oily sewage to the stirring device 2 at different heights when the stirring device 2 is running. In the present embodiment, 5 pressure sensors are installed on different stirring rods 24, respectively arranged at 40 cm, 45 cm, 50 cm, 55 cm, and 60 cm from the bottom of the tank body, and a pressure sensor is installed on one of the support rods 23, 70cm away from the bottom of the separation tank. When the stirring rod 24 is stirring the oily sewage, it is resisted by the oily sewage. Wherein, the resistance of the sludge layer to the stirring rod 24 is obviously greater than the resistance of the water layer or the oil layer to the stirring rod 24 . According to the resistance value of the stirring rod 24 during the stirring process, it can be judged whether the oily sewage at the same height as the pressure sensor is a sludge layer, an oil layer or a water layer.

The controller is used to: 1. Control the operation of the stirring device 2 according to a preset cycle T _c1 so as to make the sludge at the bottom of the separation tank 90 mix evenly, and at the same time collect the resistance value F _n measured by each pressure sensor. Since the static settlement process of oily sewage is uncontrollable and the amount of separated sludge is difficult to determine, it is obviously difficult to discharge sludge in real time or periodically to meet the discharge requirements. In order to maintain the fluidity of the sludge and prevent the sludge from agglomerating, the sludge can be stirred regularly.

2. According to the measured resistance value _Fn, look up the corresponding sludge moisture content in a pre-stored conversion table. The conversion table represents the mapping relationship between the resistance value of the stirring device and the moisture content of the sludge. Since the resistance of the sludge to the stirring device 2 is significantly greater than that of water or oil to the stirring device 2, by collecting the resistance values of the stirring device 2 at different heights in real time during the stirring process, the Sludge moisture content of oily sewage. Among them, the conversion table can be obtained through pre-experiment. The conversion table can be obtained by the following method: set sludge with different moisture content, for example, starting from a moisture content of 70%, increasing it by 1% each time until the moisture content reaches 95%. The stirring device 2 is placed in the sludge with different water contents in sequence, and the stirring is carried out according to the preset stirring speed, and the corresponding resistance value is collected. A conversion table is established according to the water content and its corresponding resistance value.

3. Calculate the sludge depth according to the moisture content of the sludge at different heights, and judge whether the sludge depth is higher than a preset depth h ₀ , and if so, activate the discharge device to discharge the sludge in the separation tank. The oily sewage with a water content of not higher than 80% is set as the sludge layer, and the depth of the sludge layer is the depth of the oily sewage with a water content of 80%. Since the density of sludge is greater than that of water, and the higher the water content of sludge, the lower the density. Assuming that the sludge moisture content of multiple detection points not higher than h ₁ is lower than 80%, and the sludge moisture content of the detection points higher than h ₁ is greater than 80%, set the sludge moisture content of h ₁ is ω _w1 , and the moisture content of the sludge at the last detection point h ₂ higher than h ₁ is ω _w2 , then the actual depth h of the sludge can be expressed as:

h=h ₁ +∣ω _w1 −80%∣(h ₂ −h ₁ )/(ω _w2 −ω _w1 ).

For example, the moisture content of sludge at a depth of 50cm is 79%, and the moisture content of sludge at a depth of 55cm is 83%, then the sludge depth is h=50+∣79%-80%∣(55-50)/(83 %-79%) = 51.25 cm.

The automatic sludge discharge device in this embodiment can not only mix the sludge layer uniformly by regularly stirring the sludge at the bottom of the separation tank, avoid clogging caused by coagulation and adhesion, but also can more accurately measure the depth of the sludge layer, so that When the sludge layer reaches the preset depth, the bottom sludge is discharged at one time. Compared with manual sludge discharge, the automatic sludge discharge device of this embodiment can discharge the sludge in a timely and rapid manner, preventing the sludge from agglomerating into blocks, blocking the separation tank, and generating peculiar smell. Compared with regular sludge discharge, the automatic sludge discharge device of this embodiment discharges more accurately, can avoid discharging oil and water, avoids secondary pollution to the environment, and is more energy-efficient and reduces operating costs.

The water inlet device 20 communicates with the separation tank 90 and is used for introducing oily sewage into the separation tank 90 . The water inlet device 20 includes a submersible sewage pump, a water inlet pipe and two electric valves. Submersible sewage pumps are installed in sumps used to store oily sewage. The inlet end of the water inlet pipe communicates with the submersible sewage pump, and the outlet end of the water inlet pipe communicates with the separation tank 90 . The second electric valve is installed on the water inlet pipe and is used to control the on-off state of the water inlet pipe. The connection between the water inlet pipe and the separation tank 90 is located in the middle of the separation tank 90, above the preset discharge height.

The oily sewage is stratified in the separation tank 90, gradually forming an oil layer, a water layer and a sludge layer from top to bottom. During this process, there is an unseparated oil-water mixed layer between the oil layer and the water layer. When the sludge layer reaches the preset discharge depth (such as 1/3 height of the separation tank) for discharge, the liquid level of the oily sewage in the separation tank drops, and the oily sewage can be continuously replenished into the separation tank. The supplementary oily sewage should preferably be in the oil-water mixed layer to avoid disturbing the separated oil layer and water layer. Since the rate of solid-liquid separation (separation of sludge layer from liquid oil layer and water layer) in oily sewage is greater than the rate of oil-water separation, timely discharge of sludge and replenishment of oily sewage can effectively use the volume of the separation tank and improve the efficiency of oily sewage. three-phase separation efficiency.

A three-way valve includes an input and two outputs. The input end communicates with the outlet end of the automatic mud discharge device. One of the outputs is used for sludge or water discharge, and the other is used for oil discharge. The oil after separation of oily sewage is used for recycling, which not only reduces environmental pollution, but also saves energy and turns waste into treasure. The separated sludge or sewage can be discharged directly if it reaches the discharge standard. The three-way valve cooperates with the oil content detector 70, and can distinguish the water layer and the oil layer by the size of the oil content during discharge, so as to realize the oil-water separation of the oily sewage.

Please refer to FIG. 3 , which is a schematic cross-sectional structure diagram of the detection device in FIG. 2 . The detection device 40 includes a housing 401 and a positioner 402 . The casing 401 is a hollow sphere. The locator 402 is fixedly connected to the spherical 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 that of oil and less than that of water. The detection device 40 is placed in the separation tank 90 for measuring its own real-time position. The oily sewage is stratified in the separation tank 90, and since the overall density of the detection device 40 is greater than that of oil and less than that of water, the detection device 40 will be suspended in the oil-water mixed layer. With the progress of oil-water separation, the oil-water mixed layer gradually decreases, the oil layer and water layer gradually increase, and the position of the oil-water mixed layer is also constantly changing. Therefore, the process of oil-water separation can be judged by measuring the position change of the detection device 40 . When the position of the detection device 40 does not change within a preset period _Tc2 , it can be considered that the oily sewage has been completely stratified, and the oily sewage can be discharged or recovered in layers.

The heating device 50 is installed at the connection between the water inlet device 20 and the separation tank 90, and is used for heating the incoming oily sewage. The heating device 50 can use an infrared heater, which can not only heat without contact, avoid being adhered by oily sewage, but also can heat evenly and quickly heat up, so as to ensure that the oily sewage enters the separation tank 90 within a preset temperature range to keep the oily sewage Grease in sewage is in the liquid phase. Of course, in other embodiments, the heating device 50 may also use a carbon fiber heating plate or the like.

The heat preservation device 60 is installed on the separation tank 90 and is used for heat preservation of the oily sewage in the separation tank 90 . The thermal insulation device can be a non-energy-consuming thermal insulation material board, such as a vacuum insulation board, a polyurethane board, a glass fiber board, an inorganic polymer insulation board, etc., or an electric heating board, such as a carbon fiber heating board, etc., as long as the oil-containing Insulation of sewage can be done. The thermal insulation device 60 should at least cover the top 2/3 of the separation tank 90 to prevent the grease from condensing into a solid phase. Distinguishing the heating process from the heat preservation process can not only improve the heating efficiency and maintain the high efficiency of the oil-water separation process, but also eliminate the need for overall heating of the oily sewage in the separation tank 90, reducing overall energy consumption and operating costs.

The oil content detector 70 is used to detect the oil content ω _o1 at the outlet end of the automatic mud discharge device. By detecting the oil content ω _o1 , the oil layer and the water layer can be distinguished when the oily sewage is discharged, and then the oil layer can be selectively recovered.

The temperature sensor 80 is used to measure the real-time temperature T ₁ of the incoming oily sewage and the average temperature T ₂ of the oily sewage in the separation tank 90 . Part of the oil in the oily sewage is in the solid phase at room temperature (25°C), the oily sewage is preheated, and the temperature of the oily sewage is measured in real time to keep the oil in the oily sewage melted into the liquid phase.

The controller of the automatic sludge discharge device can also be used as the control device of the three-phase separation equipment. Correspondingly, the controller is also used to: 1. Determine whether the temperature T ₁ and the average temperature T ₂ exceed a preset temperature range, and if so, adjust The output power of the heating device 50 or the heat preservation device 60 until the temperature T ₁ and the average temperature T ₂ are within the temperature range. In this embodiment, the preset temperature range is 40-45°C. Certainly, in other embodiments, the preset temperature range may be higher or lower.

2. Whether the detection device 40 has no height change within a preset period _Tc2 , if so, start the discharge device 1 and the oil content detector 70, and judge whether the oil content ω _o1 is higher than a preset oil content ω _s , If yes, discharge oil, otherwise discharge mud or water.

The three-phase separation equipment in this embodiment melts the solid phase oil in the oily sewage into liquid phase oil by preheating the oily sewage, so as to prevent the sludge and oil from agglomerating and being difficult to separate. The sludge at the bottom of the separation tank is discharged in time, and the oily sewage is supplemented to make full use of the effective volume of the separation tank and improve the separation efficiency of the oily sewage. Finally, by measuring the oil content of the discharged oily sewage in real time, the water layer and the oil layer can be accurately distinguished, and the oil layer can be recycled, which not only reduces secondary pollution, but also saves energy and reduces treatment costs.

Please refer to FIG. 4 , which is a flow chart of the three-phase separation method for oily sewage in this embodiment. In order to facilitate the unified operation of the above-mentioned three-phase separation equipment and realize efficient treatment of oily sewage, this embodiment also provides a three-phase separation method for oily sewage. The three-phase separation method includes the following steps:

S1: The oily sewage is heated to a preset temperature range and then introduced into a separation tank until the liquid level of the oily sewage reaches a preset height. The oily sewage in the separation tank is insulated so that the average temperature of the oily sewage in the separation tank is within the temperature range. The oily sewage in the separation tank is divided into oil layer, water layer and sludge layer from top to bottom by static sedimentation. Heat the oily sewage to the preset temperature range, so that the oil in the oily sewage melts into a liquid phase, and prevents the oil and sludge from agglomerating into blocks and is not easy to separate.

S2: Stir the oily sewage below a preset height according to a preset period _Tc1 , so that the sludge layer is evenly mixed. At the same time, the resistance value F _n of the oily sewage at different heights to the stirring device is collected during the stirring process, and then the corresponding sludge moisture content is queried in a conversion table. The conversion table represents the mapping relationship between the resistance value of the stirring device and the moisture content of the sludge. The sludge layer in the oily sewage is separated and deposited at the bottom of the separation tank. Regular stirring of the sludge can prevent the sludge from agglomerating to prevent the sludge from clogging the discharge pipe, maintain the fluidity of the sludge, and facilitate sludge discharge. The surface of the stirred sludge layer tends to be flat, which is convenient for measuring the depth of the sludge layer. At the same time, the resistance of the uniformly stirred sludge layer or water layer to the stirring device tends to be stable, and it is easier to analyze the water content of the sludge layer.

S3: Calculate the depth of the sludge according to the water content at different heights. When the depth h of the sludge is greater than a preset depth h _s , discharge the sludge and add oily sewage to the separation tank until the liquid level of the oily sewage reaches a preset height. The depth h of the sludge can be calculated by the following formula:

h=h ₁ +∣ω _w1 −80%∣(h ₂ −h ₁ )/(ω _w2 −ω _w1 ).

Among them, h ₁ is the height of the highest measurement point whose water content meets the preset range, ω _w1 is the sludge moisture content at h ₁ , h ₂ is the height of the previous detection point higher than h ₁ , and ω _w2 is h ₂ The moisture content of the sludge.

When the sludge reaches the 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 according to the preset depth and the size of the separation tank 90, or the actual volume of oily sewage calculated according to the actual depth of the sludge .

S4: When the oily sewage in the separation tank is completely stratified, discharge the oily sewage from the bottom of the separation tank, and measure the oil content ω _o1 of the oily sewage at the bottom of the separation tank at the same time, when the oil content ω _o1 is lower than a preset oil content When measuring ω _s , the water layer and sludge layer in the oily sewage are discharged directly, otherwise the oil layer in the oily sewage is recovered. Since the oil layer and the water layer have been completely separated, during the discharge process, the oil layer and the water layer can be distinguished according to the color of the manual observation, so as to control the discharge manually, and the oil layer and the water layer can also be distinguished by real-time monitoring of the oil content. , to avoid discharging the oil layer and causing secondary pollution.

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

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. An automatic sludge discharge device for oily sewage, which is used in the three-phase separation process of oily sewage to automatically discharge the sludge in the separation tank; the automatic sludge discharge device includes a discharge device, and the discharge device It communicates with the bottom of the separation tank and is used to discharge the sludge in the separation tank; it is characterized in that the automatic sludge discharge device also includes: A stirring device, which includes a motor, a rotating shaft, a plurality of support rods and a plurality of stirring rods; the rotating shaft is arranged coaxially with the bottom of the separation tank; the top of the rotating shaft passes through the separation tank and the The output end of the motor is fixedly connected; a plurality of the support rods are arranged in a circular array along the horizontal direction at the bottom end of the rotating shaft; the end of the supporting rods away from the rotating shaft is inclined downward; The array is provided with a plurality of stirring rods; each of the stirring rods is arranged vertically downward; A plurality of pressure sensors, the pressure sensors are fixedly installed on the support rod or the stirring rod, and are used to measure the resistance value F _n of the oily sewage at different heights to the stirring device when the stirring device is in operation ;as well as A controller, which is used to: 1. Control the operation of the stirring device according to a preset cycle T _c1 , so that the sludge at the bottom of the separation tank is evenly mixed, and at the same time collect the resistance value F measured by each of the pressure sensors _n ; Two, according to the measured resistance value _Fn , look up the corresponding sludge water content in a pre-stored conversion table; the conversion table represents the mapping relationship between the resistance value and the sludge water content that the stirring device is subjected to; 3. Calculating the sludge depth according to the moisture content of the sludge at different heights, judging whether the sludge depth is higher than a preset depth h ₀ , and then activating the discharge device to discharge the sludge in the separation tank. 2. The automatic sludge discharge device for oily sewage according to claim 1, characterized in that, the stirring rod has an inverted pyramid or inverted conical structure. 3. The automatic sludge discharge device for oily sewage according to claim 1, characterized in that at least one of the support rods is fixedly connected to a scraper; one side of the scraper is away from the support rod One end of the rotating shaft is fixedly connected; the other side of the scraper is attached to the bottom inner wall of the separation tank. 4. The automatic sludge discharge device for oily sewage according to claim 1, wherein the stirring device further comprises a hollow shaft; the hollow shaft is coaxially arranged outside the rotating shaft and is connected to the rotating The shaft is rotatably connected; the hollow shaft is fixedly connected with the separation tank. 5. The automatic sludge discharge device for oily sewage according to claim 1, characterized in that, the discharge device comprises a sewage pump, a sewage pipe and an electric valve; one end of the sewage pipe and the separation tank The bottom end is connected, and the other end of the sewage pipe is connected with 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 sewage, comprising a separation tank, the bottom of which is a hemispherical or chamfered frustum or rounded frustum structure; it is characterized in that the three-phase separation device is also include: The automatic sludge discharge device for oily sewage as described in any one of claims 1 to 5; A water inlet device, which communicates with the separation tank and is used to introduce oily sewage into the separation tank; A three-way valve, which includes an input port and two output ports; the input port communicates with the outlet port of the automatic mud discharge device; one of the output ports is used for mud discharge or drainage, and the other output port for oil drainage; and A detection device, which includes a housing and a locator; the housing is a hollow sphere; the locator is fixedly connected at the center of the housing to measure the position of the housing in real time; the detection device The overall density of the oil is greater than that of oil and less than that of water; the detection device is placed in the separation tank for measuring its own real-time position. 7. The three-phase separation equipment for oily sewage according to claim 6, wherein the water inlet device comprises a submersible sewage pump, a water inlet pipe and two electric valves; the submersible sewage pump is installed in the In the sump of oily sewage; the inlet end of the water inlet pipe communicates with the submersible sewage pump, and the outlet end of the water inlet pipe communicates with the separation tank; the electric valve 2 is installed on the water inlet pipe for To control the on-off state of the water inlet pipe. 8. The three-phase separation equipment for oily sewage 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 between the water inlet device and the The joint of the separation tank is used for heating the oily sewage entering the water; the heat preservation device is installed on the separation tank and used for heat preservation of the oily sewage in the separation tank. 9. The three-phase separation device for oily sewage according to claim 7 or 8, characterized in that, the three-phase separation device also includes an oil content detector and a plurality of temperature sensors; To detect the oil content ω _o1 at the outlet of the automatic sludge discharge device; the temperature sensor is used to measure the real-time temperature T ₁ of the oily sewage entering the water and the average temperature T ₂ of the oily sewage in the separation tank; The controller of the automatic mud discharge device is also used for: 1. judging whether the temperature _T1 and the average temperature _T2 exceed a preset temperature range, and if so, adjust the output power of the heating device or the heat preservation device until The temperature T ₁ and the average temperature T ₂ are within the temperature range; 2. Judging whether the detection device has no height change within a preset period _Tc2 , and if so, start the automatic mud discharge device The discharge device and the oil content detector determine whether the oil content ω _o1 is higher than a preset oil content ω _s , and if yes, discharge the oil; otherwise, discharge mud or water. 10. A three-phase separation method for oily sewage, which is applied to the three-phase separation equipment for oily sewage as claimed in any one of claims 6 to 9, characterized in that, the three-phase separation method Including the following steps: S1: Heat the oily sewage to a preset temperature range and then introduce it into a separation tank until the liquid level of the oily sewage reaches a preset height; keep the oily sewage in the separation tank warm so that the separation The average temperature of the oily sewage in the tank is within the temperature range; the oily sewage in the separation tank is divided into an oil layer, a water layer and a sludge layer from top to bottom by standing and settling; S2: According to a preset period T _c1 , stir the oily sewage below a preset height to make the sludge layer mix evenly; at the same time, collect the resistance value F _n of the oily sewage at different heights to the stirring device during the stirring process, Then query the corresponding sludge water content in a conversion table; the conversion table represents the mapping relationship between the resistance value of the stirring device and the sludge water content; S3: Calculate the depth of the sludge according to the water content at different heights. When the depth h of the sludge is greater than a preset depth h _s , discharge the sludge, and replenish the oily sewage into the separation tank until the liquid of the oily sewage surface reaches a preset height; S4: When the oily sewage in the separation tank is completely stratified, discharge the oily sewage from the bottom of the separation tank, and measure the oil content ω _o1 of the oily sewage at the bottom of the separation tank at the same time, when the oil content ω _o1 is lower than one When the preset oil content ω _s , the water layer and the sludge layer in the oily sewage are discharged directly, otherwise the oil layer in the oily sewage is recovered.

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