A waste mineral oil recycling device for purifying wastewater in waste mineral oil

Abstract

The present invention discloses a waste mineral oil recycling device for purifying wastewater in waste mineral oil, which relates to the technical field of wastewater treatment. The present invention includes an outer housing, an inlet pipe is installed on one side of the outer housing, and an exhaust pipe is installed on the top. On one side of the middle part of the outer housing away from the inlet pipe, an oil discharge pipe is installed, and a drain pipe is installed at the bottom. Inside the outer housing, a bottom support plate is installed at the bottom, a second separation member is installed at the top of the bottom support plate, a partition is installed on one side of the top of the second separation member, and a first separation member is installed between the inner wall of the outer housing and one side of the partition. The inlet pipe is communicated with the first separation member, the oil discharge pipe is communicated with the second separation member, and the bottom of the drain pipe is connected to an oil separation tank. By first discharging the non-condensable gas in the top distillate and setting the second separation member to separate the oil-water mixture after reducing the turbulent flow, and cooperating with the secondary separation of the oil separation tank, the wastewater is effectively separated and treated.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and particularly relates to a waste mineral oil recycling device for purifying wastewater in waste mineral oil. Background Art

[0002] The components of waste mineral oil are relatively complex, including light oil, medium oil, heavy oil, water and other components. During the recycling process, fractional distillation treatment needs to be carried out through a fractionating tower. The light oil generated after fractional distillation and passing through a cooler contains some non-condensable gases with relatively low boiling points that cannot be liquefied, and at the same time contains a small amount of water. These three components form a mixture and are discharged from the cooler. Since the gas, oil and water in this mixture are mixed with each other, the light oil in the waste mineral oil needs to be separated before it can be effectively recycled.

[0003] The patent specification with publication number CN108893136B discloses a method for treating the waste oil generated by large steam blowing in delayed coking. During large steam blowing in delayed coking, the high-temperature oil and gas at the top of the coke tower are thrown into the lower part of the venting tower. The high-temperature oil and gas are separated in the venting tower. The steam and light oil are separated into the waste oil at the top of the tower. After being condensed by the heat exchanger at the top of the venting tower, they enter the liquid separation tank of the venting tower. The heavy oil is separated and settled into the waste oil at the bottom of the tower and flows out from the bottom of the tower. Part of the condensed waste oil at the top of the tower flows back from the liquid separation tank of the venting tower to the upper part of the venting tower through the waste oil pump at the top of the venting tower, and the other part flows back from the liquid separation tank of the venting tower to the water supply pipeline at the bottom of the coke tower through the waste oil pump at the top of the venting tower under the action of the reflux pipeline pump and enters the coke tower for recycling;

[0004] After fractionating the light oil, this technical solution re-fractionates a part of the mixture containing water and non-condensable gas, and a part of it flows back to the heating furnace to separate and recycle the mixture. The disadvantage of this technical solution is that after secondary fractionation and flowing back to the heating furnace, the water in the mixture will not disappear and will re-form along with the distillate after being cooled. Therefore, the water in the light oil has never been effectively separated and treated, which is harmful to the environment after being discharged, that is, the wastewater in the light oil mixture cannot be effectively separated and treated during the light oil recovery process. Summary of the Invention

[0005] The purpose of the present invention is to provide a waste mineral oil recycling device for purifying wastewater in waste mineral oil, and the technical problems to be solved are as follows: During the process of recovering light oil by the existing waste mineral oil recovery device, the wastewater in the cooled light oil mixture cannot be effectively separated and treated.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A waste mineral oil recycling device for purifying wastewater in waste mineral oil, comprising a housing body. An inlet pipe is installed on one side of the housing body, and an exhaust pipe is installed on the top. On one side of the middle of the housing body away from the inlet pipe, an oil discharge pipe is installed, and a drain pipe is installed at the bottom. At the bottom inside the housing body, a bottom support plate is installed. At the top of the bottom support plate, a second separator is installed. On one side of the top of the second separator, a partition plate is installed. Between the inner wall of the housing body and one side of the partition plate, a first separator is installed. The inlet pipe is communicated with the first separator, and the oil discharge pipe is communicated with the second separator. The first separator is used for separating non-condensable gas, and the second separator is used for separating light oil and wastewater. The bottom of the drain pipe is connected to an oil separation tank, and the oil separation tank is used for secondary separation of the wastewater.

[0008] As a further scheme of the present invention: The housing body includes a bottom bin, and a top bin is arranged at the top of the bottom bin. A plurality of bolts are evenly installed along the outer side of the ring between the adjacent surfaces of the bottom bin and the top bin.

[0009] As a further scheme of the present invention: The first separator includes a plurality of filter plates arranged evenly. The filter plates and the partition plate form an angle of 45 - 60 degrees in the horizontal direction. The bottom of the filter plates abuts against the bottom support plate, the arc-shaped side surfaces of the filter plates abut against the inner wall of the housing body, and the other side is fixedly connected to the partition plate.

[0010] As a further scheme of the present invention: The bottom surface of the bottom support plate is evenly provided with liquid passing holes, and a baffle is arranged on the other side. The partition plate is inserted into the inside of the housing body and is close to the side of the inlet pipe.

[0011] As a further scheme of the present invention: The second separator includes obliquely arranged sedimentation tubes, and the sedimentation tubes are fixedly connected to each other. The arc-shaped side surface of the second separator fits with the inner wall of the housing body. The inner side of the top of the second separator abuts against the partition plate. The second separator is inserted into the inside of the housing body, and the bottom surface fits with the top of the bottom support plate.

[0012] As a further scheme of the present invention: The height of the partition plate is greater than the height of the top of the first separator, the height of the second separator is lower than the height of the first separator. A side liquid port is arranged between the bottom end of the partition plate and the adjacent surface of the second separator. A water storage cavity is arranged at the bottom of the bottom bin, and the bottom of the water storage cavity is communicated with the drain pipe.

[0013] As a further scheme of the present invention: An observation column is installed on one side of the housing body close to the oil discharge pipe. The inner sides of both ends of the observation column are communicated with the inside of the housing body. The top of the observation column is higher than the top of the second separator, and the bottom end is lower than the top of the second separator. A viewing window is arranged on the outer side of the observation column.

[0014] As a further solution of the present invention: the installation height of the inlet pipe is higher than the top height of the second separator, the installation height of the drain pipe is located in the middle of the second separator, a water viewing window is installed below the drain pipe on the outer shell, and control valves are installed on the inlet pipe, the exhaust pipe, the drain pipe and the drain pipe.

[0015] As a further solution of the present invention: the oil separator includes an oil separation chamber one connected to the drain pipe, an oil separation chamber two and an oil separation chamber three are sequentially connected to one side of the oil separation chamber one, an intermediate partition plate is provided in the middle of both the oil separation chamber one and the oil separation chamber two, a connecting pipe is installed between the bottoms of two adjacent oil separation chambers, an oil suction branch pipe is installed at the top of each oil separation chamber close to the drain pipe, and the lengths of the oil suction branch pipes gradually decrease in the direction away from the drain pipe, and a water outlet pipe is installed on one side of the top of the oil separation chamber three away from the drain pipe.

[0016] The beneficial effects of the present invention:

[0017] 1. In the present invention, after the fractionating column fractionates the top fraction and cools it, the top fraction is injected into the outer shell through the inlet pipe. After the top fraction enters the outer shell, it collides with the first separator and separates the non-condensable gas. The non-condensable gas is discharged from the top of the outer shell. The remaining oil-water mixture in the top fraction then contacts the second separator at the bottom of the first separator. The second separator statically separates the oil-water mixture through the obliquely densely arranged sedimentation pipes. The separated oil and water enter the bottom bin at the bottom of the inner part of the outer shell through the liquid passing holes on one side of the bottom support plate, and are finally discharged through the drain pipe and the drain pipe respectively. That is, the top fraction composed of non-condensable gas, wastewater and light oil is separated into components in the mixture by the first separator and the second separator one by one after entering the device, realizing the recovery of the top fraction after mineral oil fractionation and the function of wastewater separation; when separating wastewater, since the top fraction is first intercepted and slowed down by the partition plate and the first separator after entering the device, and the non-condensable gas that interferes with the oil-water separation is first removed, its technical advantage is that when the oil-water mixture enters the second separator for sedimentation, it is no longer affected by the turbulent flow of the high-speed fluid, and the obliquely arranged sedimentation pipes block each other. Then the oil-water mixture can quickly enter the oil-water stratification state after removing the non-condensable gas, and is discharged one by one after the stratification is completed. That is, on the basis of realizing the separation function of the wastewater in the top fraction, the separation efficiency of the wastewater is accelerated;

[0018] Further, after the wastewater is discharged from the drain pipe, it is connected to an oil separation tank for secondary separation. Relying on the three oil separation chambers in the oil separation tank and the oil suction branch pipes installed at the top of each oil separation chamber, the separated wastewater is subjected to secondary oil-water separation. That is to say, in this case, after the wastewater is separated by the top fraction separation equipment, it is further subjected to more thorough secondary oil-water separation through the oil separation tank. An integrated technical solution for wastewater separation in the top fraction is constructed with the help of the device and the oil separation tank, aiming to effectively solve the problem of water content in light oil during waste mineral oil recovery, thereby improving the recovery quality of light oil and facilitating the subsequent unified centralized treatment of wastewater, avoiding omission during the separation process and causing environmental pollution.

[0019] 2. In the present invention, after the wastewater is discharged from the oil separation tank, it is successively sent to the air flotation tank and the biochemical tank for treatment. Since the omission amount during the separation process is extremely small, after being treated by the air flotation tank and the biochemical tank, the degree of environmental pollution caused by the wastewater generated during the recycling of waste mineral oil is reduced. Moreover, during the recycling of waste mineral oil, the wastewater discharged from the pretreatment process, the bottom discharge of the fractionation tower, the top fraction, and the middle fraction are all concentrated in the wastewater treatment tank for treatment, thereby effectively reducing the pollution effect of the wastewater generated during the recycling of waste mineral oil on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 is the overall structural schematic diagram of the present invention;

[0022] Figure 2 is the partial internal structural schematic diagram of the present invention;

[0023] Figure 3 is the present invention Figure 2 The enlarged detail view of part A in;

[0024] Figure 4 is the side schematic diagram of the partial internal structure of the present invention;

[0025] Figure 5 is the present invention Figure 4 The enlarged detail view of part B in;

[0026] Figure 6 is the bottom view of the partial internal structure of the present invention;

[0027] Figure 7 is the internal structural schematic diagram of the connected oil separation tank of the present invention;

[0028] Figure 8 is the flow chart of waste petroleum recovery fractionation.

[0029] In the figure: 1. Outer shell; 2. Inlet flow pipe; 3. Exhaust pipe; 4. Oil drain pipe; 5. Drain pipe; 6. Bottom support plate; 61. Liquid passing hole; 62. Baffle plate; 7. Partition plate; 8. Separation member one; 81. Filter plate; 9. Separation member two; 91. Calm pipe; 10. Oil separation tank; 11. Bottom bin; 12. Top bin; 13. Bolt; 14. Water storage cavity; 15. Observation column; 16. View window; 17. Control valve; 18. Oil separation chamber one; 19. Oil separation chamber two; 20. Oil separation chamber three; 21. Intermediate partition plate; 22. Connecting pipe; 23. Oil suction branch pipe; 24. Outlet water pipe; 25. Water view window; 26. Side liquid port. Detailed implementation manners

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] As Figure 8As shown in the figure, when recycling waste mineral oil, the waste mineral oil needs to be first put into a pretreatment tank for treatment. The pretreatment tank includes multiple stages of oil storage tanks and a filtration tank. The waste oil undergoes multiple stages of sedimentation and filtration here to remove the large-particle waste residues. Subsequently, the waste oil is pumped into a preheating oil tank. The preheating oil tank heats the input waste oil to 80 degrees. After heating, the waste oil starts to stratify from the oil-water mixed state. Subsequently, the wastewater in the preheating oil tank is pumped out from the bottom and discharged into a wastewater treatment tank for treatment. The waste oil at the top is pumped out and conveyed into a heater. The heater is heated by a hot blast stove and heats the input waste oil to 350 - 400 degrees. And a homogeneous catalyst is put into the heater during heating to convert some macromolecular organic esters in the waste oil into simple esters, making its molecular structure closer to hydrocarbons, which is convenient for later fractionation. Subsequently, this part of the waste oil is put into a fractionating tower. Multiple layers of alternately arranged heat exchangers and fillers are provided in the fractionating tower, and a catalyst layer for fractionation is provided at the bottom of the tower. After fractionation, the lighter light fraction is discharged from the top of the fractionating tower, the heavier middle fraction is discharged from the middle of the tower. After some of the fractions are discharged from the bottom of the tower, they are heated by a reboiler and re-input into the fractionating tower for fractionation, and after being discharged, they are cooled by cooler one and cooler two and then separated. Among them, the light fraction contains a large amount of non-condensable gas, light oil and a small amount of water. The non-condensable gas contains small-molecule hydrocarbon gases with relatively low boiling points, such as alkanes, alkenes, etc. Their boiling points are too low to be separated by conventional cooling and liquefaction. After the waste oil fed into the fractionating tower is heated at a high temperature of 300 to 400 degrees, the wastewater contained in it also undergoes gasification. Then the non-condensable gas and wastewater vapor gather at the top of the tower during fractionation and are conveyed into cooler one for liquefaction. The liquid oil-water mixture is conveyed to the top fraction separation device together with the non-condensable gas, and it is necessary to separate the wastewater and non-condensable gas to obtain the final light oil. At the same time, the middle fraction will also discharge some wastewater after being separated by the middle fraction separation device. The wastewater generated after the top fraction separation and the middle fraction separation is refluxed to the wastewater treatment tank together for treatment, thus completing the fractionation recovery of waste mineral oil and the purification of wastewater.

[0032] As Figures 1 to 8 As shown in the figure, a waste mineral oil recycling device for purifying wastewater in waste mineral oil includes a housing 1. An inlet pipe 2 is installed on one side of the housing 1, and an exhaust pipe 3 is installed on the top. On the side of the middle part of the housing 1 away from the inlet pipe 2, an oil discharge pipe 4 is installed, and a drain pipe 5 is installed at the bottom. A bottom support plate 6 is installed at the bottom inside the housing 1. A separator two 9 is installed at the top of the bottom support plate 6. A partition 7 is installed on one side at the top of the separator two 9. A separator one 8 is installed between the inner wall of the housing 1 and one side of the partition 7. The inlet pipe 2 is communicated with the separator one 8, the oil discharge pipe 4 is communicated with the separator two 9. The separator one 8 is used to separate non-condensable gas, and the separator two 9 is used to separate light oil and wastewater. The drain pipe 5 is connected to an oil separation tank 10;

[0033] It should be noted that this device, namely Figure 8 the overhead fraction separation equipment connected to the rear end of cooler 1, is used to process the light oil mixture after fractionation, including separating the non-condensable gas and wastewater therein, and finally obtaining the required light oil. The separated wastewater is transported to the wastewater treatment pool for treatment, thereby realizing the functions of recovering light oil and cleaning wastewater.

[0034] As Figure 2 shown, the outer casing 1 includes a bottom bin 11, a top bin 12 is arranged at the top of the bottom bin 11, and a plurality of bolts 13 are evenly installed along the outer side of the ring between the adjacent surfaces of the bottom bin 11 and the top bin 12;

[0035] It should be noted that since the first separating member 8 and the second separating member 9 are installed inside the outer casing 1, and the performance of both the first separating member 8 and the second separating member 9 will gradually decrease with the extension of the service time, replacement is required. By setting the outer casing 1 as a split structure fixed by bolts 13, the first separating member 8 and the second separating member 9 can be overhauled and replaced after being used for a period of time, thereby maintaining the service performance of the device. Preferably, a rubber gasket is installed between the connecting surfaces of the bottom bin 11 and the top bin 12. The gasket is made of fluororubber with high temperature resistance and strong gasoline tolerance to maintain the long-term sealing performance of the overall outer casing 1. In addition, the side of the outer casing 1 connected to the drain pipe 4 at the lower part is integrally sealed and welded.

[0036] As Figure 2 and Figure 6 shown, the first separating member 8 includes a plurality of filter plates 81 arranged evenly. Each filter plate 81 forms an angle of 45 - 60 degrees with the partition plate 7 in the horizontal direction. The filter plate 81 is fiber mesh-shaped. The bottom of the filter plate 81 abuts against the bottom support plate 6, the arc side of the filter plate 81 abuts against the inner wall of the outer casing 1, and the other side is fixedly connected to the partition plate 7;

[0037] Liquid passing holes 61 are evenly arranged on one side of the bottom support plate 6 close to the drain pipe 4, and a baffle 62 is arranged on the other side. The partition plate 7 is inserted inside the outer casing 1 and is on the side close to the inlet pipe 2;

[0038] It should be noted that after the inlet pipe 2 conveys the mixture of non-condensable gas, light oil such as gasoline, and part of the wastewater into the inner part of the outer shell 1, the substances conveyed to the filter plate 81 are divided into the liquid phase of wastewater and light oil and the gas phase of non-condensable gas at this time. After being conveyed into the inner part of the outer shell 1, they collide with each filter plate 81 of the first separator 8. Since each filter plate 81 is obliquely arranged and is in the form of a fiber network, the non-condensable gas in the gas phase floats to the top inside the outer shell 1 when passing through. The liquid phase part is slowly dispersed and intercepted by fully contacting the filter plate 81, and at the same time, it falls along the filter plate 81 by its own gravity. After reaching the bottom end of the filter plate 81, it first contacts the second separator 9, and then contacts the baffle 62 on the bottom surface of the bottom support plate 6, so as to ensure that the liquid phase can be conducted from the first separator 8 to the second separator 9, and there is enough time and space for oil-water separation at the second separator 9. The liquid phase after oil-water separation by the second separator 9 passes through the liquid passing holes 61 on the other side to transfer the separated wastewater to the bottom inside the outer shell 1. The gaseous non-condensable gas is discharged from the exhaust pipe 3 after rising to the top of the outer shell 1. The partition plate 7 is inserted on one side close to the inlet pipe 2. The purpose is to prevent the non-condensable gas from being directly filled into the part of the second separator 9, thereby generating bubbles and affecting the subsequent static sedimentation separation process of water and oil;

[0039] In this process, the material of the first separator 8 includes but is not limited to a polymer fiber network. When it is necessary to further improve the quality of oil, such as reducing the sulfur content and nitrogen content in the product, it can be replaced with a porous ceramic molecular sieve as the substrate and loaded with specific metal oxides, so that a catalytic reaction can occur when the mixture passes through. For example, molybdenum oxide is coated on the porous molecular sieve to reduce the content of sulfur dioxide and hydrogen sulfide in the product.

[0040] As Figures 2 to 4 、 Figure 6 As shown, the second separator 9 includes obliquely arranged settling pipes 91, which are fixedly connected between each other. The arc-shaped side surface of the second separator 9 fits the inner wall of the outer shell 1. The inner side of the top of the second separator 9 abuts against the partition plate 7, and the bottom is in a cylindrical shape. The second separator 9 is inserted into the inner part of the outer shell 1, and the bottom surface fits the top end of the bottom support plate 6;

[0041] The height of the partition plate 7 is greater than the height of the top end of the first separator 8. The height of the second separator 9 is lower than the height of the first separator 8. A side liquid port 26 is provided between the bottom end of the partition plate 7 and the adjacent horizontal plane of the second separator 9. A water storage cavity 14 is provided at the bottom of the bottom bin 11, and the bottom of the water storage cavity 14 is communicated with the drain pipe 5;

[0042] It should be noted that after the light fraction separates the non-condensable gas through the first separator 8, the liquid phase contains the light oil to be extracted and the wastewater to be separated. This mixture falls to the bottom of the cylindrical second separator 9 after being buffered and dispersed by each filter plate 81 of the first separator 8. After the oil-water separation in the sedimentation tube 91 in the bottom area of the second separator 9, it falls into the water storage chamber 14 through the liquid passing hole 61 on the other side of the bottom support plate 6. Since the incoming liquid is blocked by the partition plate 7 and does not directly enter the sedimentation tube 91, and the sedimentation tube 91 is obliquely distributed vertically and blocked from each other, the turbulent flow phenomenon of the oil-water mixture is greatly weakened after entering the sedimentation tube 91, enabling the oil-water mixture to quickly enter the sedimentation and separation state. Furthermore, during the separation process, the non-condensable gas is discharged first by the first separator 8, and there is no bubble interference during the oil-water stratification, thus achieving the effect of improving the efficiency of waste oil recovery and wastewater separation. As the liquid entering the outer shell 1 increases, the separated light oil is located in the upper layer of the second separator 9 due to its lower density, and the separated wastewater with a higher density is located in the lower layer of the second separator 9. The bottom wastewater accumulates in the water storage chamber 14 and is finally discharged into the wastewater treatment pool through the drain pipe 5;

[0043] In addition, the height of the partition plate 7 is the highest, so that after the mixture is filled into the inner part of the outer shell 1, it will not cross the partition plate 7 and enter the second separator 9, reducing the possibility of generating turbulent flow. And the height of the second separator 9 is in a lower state for subsequent observation and timely discharge of the separated light oil to avoid crossing the partition plate 7 and mixing with the mixture in the first separator 8. At the bottom of the partition plate 7, since a side liquid port 26 is provided between the first separator 8 and the second separator 9, the oil-water mixture after removing the non-condensable gas can spread to each sedimentation tube 91 as early as possible and over a large range at the bottom of the second separator 9, thereby improving the oil-water separation efficiency.

[0044] As Figure 4 and Figure 5 shown, an observation column 15 is installed on one side of the outer shell 1 close to the oil drain pipe 4. The inner sides at both ends of the observation column 15 are communicated with the inside of the outer shell 1. The top of the observation column 15 is higher than the top of the second separator 9, and the bottom is lower than the top of the second separator 9. A viewing window 16 is provided on the outer side of the observation column 15;

[0045] The installation height of the inlet pipe 2 is higher than the top height of the second separator 9, the installation height of the oil drain pipe 4 is in the middle of the second separator 9, a viewing water window 25 is installed under the oil drain pipe 4 on the outer shell 1, and control valves 17 are installed on the inlet pipe 2, the exhaust pipe 3, the oil drain pipe 4 and the drain pipe 5;

[0046] It should be noted that with the continuous input of fluid through the inlet pipe 2, the storage volume of the fluid inside the outer casing 1 continuously increases, and the observation column 15 connected to the inner cavity of the outer casing 1 continuously fills with liquid. When the height of the internal oil-water mixture can be observed through the viewing window 16, the liquid level inside the outer casing 1 at this time is controlled by adjusting the opening degrees of the inlet pipe 2 and the drain pipe 4. Relying on the sedimentation effect of the sedimentation pipe 91 of the second separating member 9, the drain pipe 4 and the drain pipe 5 respectively discharge wastewater and light oil, thereby continuously separating the top fraction of the fractionating tower. Preferably, the control valve 17 is an electronic valve, and the staff can control the opening state through a handheld control terminal. In addition, a liquid level sensor is provided inside the outer casing 1 to detect the liquid level height, or manual intervention can be carried out by observing the viewing window 16. In addition, since the proportion of wastewater is relatively small, the drain pipe 5 at the bottom is intermittently opened. The basis for opening is to observe the water-oil interface through the water viewing window 25 and determine whether to open. Both the viewing window 16 and the water viewing window 25 are made of high-strength glass;

[0047] The height of the inlet pipe 2 is relatively high. On the one hand, it can quickly discharge non-condensable gases. When the oil-water mixture is intercepted by the filter plate 81, it can have enough travel during the falling process to be fully dispersed, and at the same time release a small amount of non-condensable gases inside the liquid phase. On the other hand, it can avoid the increase of internal liquid accumulation, prevent non-condensable gases from filling into the liquid to generate bubbles, and affect the oil-water separation process of the subsequent second separating member 9. The drain pipe 4 is located in the middle of the second separating member 9, which is convenient for the convenient discharge of the separated light oil.

[0048] As Figure 7 shown, the oil separation tank 10 includes an oil separation chamber 18 connected to the drain pipe 5. One side of the oil separation chamber 18 is sequentially connected to an oil separation chamber 19 and an oil separation chamber 20. Partition plates 21 are provided in the middle of both the oil separation chamber 18 and the oil separation chamber 19. Connecting pipes 22 are installed between the bottoms of adjacent oil separation chambers. Oil suction branch pipes 23 are installed at the top of each oil separation chamber close to the drain pipe 5, and the lengths of the oil suction branch pipes 23 gradually decrease in the direction away from the drain pipe 5. A water outlet pipe 24 is installed on the side of the top of the oil separation chamber 20 away from the drain pipe 5;

[0049] It should be noted that there is still a small amount of light oil remaining in the waste water accumulated in the water storage chamber 14 inside the outer shell 1. After it is discharged along the drain pipe 5, it does not directly enter the treatment process. Instead, it needs to be discharged into the oil separation tank 10 for secondary separation. Specifically, the end of the drain pipe 5 far from the water storage chamber 14 is connected to the middle of the first oil separation chamber 18. After entering the first oil separation chamber 18, it is blocked and buffered by the inner partition plate 21 inside it, and will not directly enter the second oil separation chamber 19 connected by the connecting pipe 22. Instead, oil-water separation is carried out. After separation, the waste water at the bottom enters the second oil separation chamber 19. There is still a small amount of light oil in this part of the waste water. After separation inside it, it finally enters the third oil separation chamber 20 for final extraction and separation of a very small amount of light oil. Since the thickness of the separated light oil on the top layer of each oil separation chamber close to the drain pipe 5 gradually decreases, and there is more oil on the side close to the drain pipe 5, oil suction branch pipes 23 with gradually shortened lengths are installed on the side of the top of the oil separation tank 10 close to the drain pipe 5 to timely extract the stratified light oil. Until there is only waste water left at the top of the side of the third oil separation chamber 20 far from the connecting pipe 22, the waste water is pumped out by the water outlet pipe 24 for treatment. That is, through the device and the oil separation tank 10, multiple separations of the waste water are carried out, realizing the complete separation function of the waste water of the top fraction of the fractionating tower; preferably, an L-shaped oil separation plate is fixedly connected to one side inside the water outlet pipe 24 to block a very small amount of light oil close to the oil suction branch pipe 23.

[0050] As Figure 8 shown, the waste water treatment pool includes an oil separation tank 10, a flotation tank and a biochemical tank. Specifically, after the flotation tank receives the waste water discharged from the water outlet pipe 24 of the oil separation tank 10, by adjusting the pH value of the waste water and adding a coagulant and a flocculant, the small particle oil droplets and suspended pollutants in the waste water aggregate into clusters under the flocculation effect and are carried to the liquid surface by the dissolved air bubbles and removed by the slag scraper; subsequently, the waste water after flotation treatment is sent to the biochemical tank for further treatment. The active bacteria loaded on the biological filler in the biochemical tank further decompose the pollutants in the waste water, especially decompose the macromolecular organic matter into small molecular organic matter, and then decompose it into stable inorganic substances such as carbon dioxide and sulfates, thus completing the purification treatment of the waste water.

[0051] In addition, as Figure 8 can be seen, when recycling waste mineral oil, the waste water generated during pretreatment, the waste water discharged from the bottom during the fractionation process, the waste water separated from the top fraction and the waste water separated from the middle fraction are all centrally put into the waste water treatment pool for unified treatment. The purpose is to realize the fractionation and recovery of mineral oil while separating, extracting and treating the waste water, so that the waste water treatment of waste mineral oil can effectively meet the discharge standard and improve the environmental protection intensity.

[0052] The above has described in detail an embodiment of the present invention, but the above content is only a preferred embodiment of the present invention and cannot be considered as defining the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A waste mineral oil recycling device for purifying wastewater in waste mineral oil, comprising an outer housing (1), a feed pipe (2) is installed on one side of the outer housing (1), and an exhaust pipe (3) is installed on the top. A drain pipe (4) is installed on one side of the middle part of the outer housing (1) away from the feed pipe (2), and a drain pipe (5) is installed at the bottom, characterized in that, Inside the outer shell (1), a bottom support plate (6) is installed at the bottom. At the top of the bottom support plate (6), a second separator (9) is installed. On one side of the top of the second separator (9), a partition plate (7) is installed. Between the inner wall of the outer shell (1) and one side of the partition plate (7), a first separator (8) is installed. The inlet pipe (2) is communicated with the first separator (8), and the oil discharge pipe (4) is communicated with the second separator (9). The first separator (8) is used to separate non-condensable gas, and the second separator (9) is used to separate light oil and wastewater. The bottom of the drain pipe (5) is connected to an oil interceptor (10), and the oil interceptor (10) is used for secondary separation of wastewater. The first separator (8) includes a plurality of filter plates (81) arranged evenly. The filter plates (81) form an angle of 45 - 60 degrees with the partition plate (7) in the horizontal direction. The bottom of the filter plates (81) abuts against the bottom support plate (6), the arc-shaped side of the filter plates (81) abuts against the inner wall of the outer shell (1), and the other side is fixedly connected to the partition plate (7). The second separator (9) includes obliquely arranged settling tubes (91). The settling tubes (91) are fixedly connected to each other. The arc-shaped side of the second separator (9) fits against the inner wall of the outer shell (1). The inner side of the top of the second separator (9) abuts against the partition plate (7), and the bottom is cylindrical. The second separator (9) is inserted into the inner part of the outer shell (1), and the bottom surface fits against the top of the bottom support plate (6). The height of the partition plate (7) is greater than the height of the top of the first separator (8). The height of the second separator (9) is lower than the height of the first separator (8). A side liquid port (26) is arranged between the bottom end of the partition plate (7) and the adjacent surface of the second separator (9). A water storage cavity (14) is arranged at the bottom of the outer shell (1), and the bottom of the water storage cavity (14) is communicated with the drain pipe (5).

2. The waste mineral oil recycling device for purifying wastewater in waste mineral oil according to claim 1, wherein, The outer shell (1) includes a bottom bin (11). At the top of the bottom bin (11), a top bin (12) is arranged. A plurality of bolts (13) are evenly installed along the outer side of the ring between the adjacent surfaces of the bottom bin (11) and the top bin (12).

3. The waste mineral oil recycling device for purifying wastewater in waste mineral oil according to claim 1, characterized in that, Liquid passing holes (61) are evenly arranged on the bottom surface of the bottom support plate (6), and a baffle (62) is arranged on the other side. The partition plate (7) is inserted into the inner part of the outer shell (1) and is close to the side of the inlet pipe (2).

4. The waste mineral oil recycling device for purifying wastewater in waste mineral oil according to claim 1, characterized in that, An observation column (15) is installed on one side of the outer shell (1) close to the oil discharge pipe (4). The inner sides of both ends of the observation column (15) are communicated with the inner part of the outer shell (1). The top of the observation column (15) is higher than the top of the second separator (9), and the bottom is lower than the top of the second separator (9). A window (16) is arranged on the outer side of the observation column (15).

5. The waste mineral oil recycling device for purifying wastewater in waste mineral oil according to claim 1, characterized in that, The installation height of the inlet pipe (2) is higher than the top height of the second separator (9). The installation height of the drain pipe (4) is at the middle part of the second separator (9). A water viewing window (25) is installed below the drain pipe (4) on the outer shell (1). Control valves (17) are installed on the inlet pipe (2), the exhaust pipe (3), the drain pipe (4), and the drain pipe (5).

6. The waste mineral oil recycling device for purifying wastewater in waste mineral oil according to claim 1, wherein The oil interceptor (10) includes an oil separation chamber one (18) connected to the drain pipe (5). An oil separation chamber two (19) and an oil separation chamber three (20) are sequentially connected to one side of the oil separation chamber one (18). Intermediate plates (21) are provided in the middle of the oil separation chamber one (18) and the oil separation chamber two (19). Connecting pipes (22) are installed between the bottoms of adjacent oil separation chambers. Oil suction branch pipes (23) are installed at the top ends of each oil separation chamber close to the drain pipe (5), and the lengths of the oil suction branch pipes (23) gradually decrease in the direction away from the drain pipe (5). A water outlet pipe (24) is installed on one side of the top of the oil separation chamber three (20) away from the drain pipe (5).

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