A separation tank, sewage treatment device and waste mineral oil resource treatment system

Abstract

The present invention belongs to the technical field of waste mineral oil recovery equipment, and provides a separation tank, a sewage treatment device, and a waste mineral oil resource processing system. The above-mentioned separation tank includes a tank body, and a separation component is arranged in the tank body. The separation component includes: a separation plate, which is arranged in the tank body, and is provided with a plurality of first through holes, and its average density is less than the density of water and greater than the density of waste mineral oil; a support seat, which is arranged in the tank body and located below the separation plate, and a first plugging portion is arranged on the top; an oil distribution pipe, whose first end extends into the tank body and the second end extends out of the tank body, and an oil inlet is arranged on it; and an opening and closing structure, which has an open state that keeps the oil inlet unobstructed and a closed state that keeps the oil inlet disconnected. The separation tank, sewage treatment device, and waste mineral oil resource processing system provided by the present invention have a simple structure, a reasonable design, a high efficiency of oil-water separation, and a better effect.

Description

Technical Field

[0001] The invention relates to the technical field of waste mineral oil recovery equipment, and in particular to a separation tank, a sewage treatment device and a waste mineral oil resource treatment system. Background Art

[0002] Waste mineral oil has a complex composition and contains a large amount of water in addition to various impurities. Therefore, in the process of recycling waste mineral oil, it is usually necessary to use a separation tank to separate the oil and water in the waste mineral oil.

[0003] However, the separation tank in the prior art not only has difficulty in recovering the layer of oil floating on the water surface, resulting in poor separation effect and efficiency, but also requires that the water be completely drained after each separation, resulting in the unrecovered oil floating on the water surface being drained away along with the water, causing a waste of resources. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide a separation tank, a sewage treatment device and a waste mineral oil resource treatment system to solve or alleviate the above-mentioned technical problems existing in the prior art.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a separation tank, comprising a tank body, wherein the tank body is provided with a liquid inlet and a liquid outlet, wherein the liquid inlet is connected to and communicates with a liquid inlet pipe, and the liquid outlet is connected to and communicates with a water outlet pipe, and a separation component is provided in the tank body, wherein the separation component comprises:

[0006] A separation plate, which is slidably disposed in the tank body, has an outer peripheral wall sealed with an inner wall of the tank body, is provided with a plurality of first through holes, and has an average density less than that of water and greater than that of waste mineral oil;

[0007] A support seat, which is arranged in the tank body and below the separation plate, is fixedly connected to the tank body, and has a first blocking portion on the top thereof corresponding to the first through hole and used for blocking the first through hole;

[0008] An oil distribution pipe, a first end of which extends into the tank body and extends upward along the axis of the tank body, and a second end of which extends out of the tank body, is fixedly connected to the tank body and is provided with an oil inlet hole, and the oil inlet hole is located above the support seat; and

[0009] An opening and closing structure, which is arranged on the oil distribution pipe and has an open state in which the oil inlet hole is kept unobstructed and a closed state in which the oil inlet hole is kept disconnected;

[0010] Among them, as the liquid level of water in the tank body drops, the separation plate drops to a position that contacts the support seat, so that the first blocking portion is inserted into the first through hole to separate the waste mineral oil and water in the tank body. At the same time, the separation plate converts the opening and closing structure from a closed state to an open state to open the oil inlet hole, so that the waste mineral oil located above the separation plate can enter the oil distribution pipe through the oil inlet hole.

[0011] Furthermore, the opening and closing structure comprises:

[0012] a sliding sleeve, which is sleeved on the oil distribution pipe and slidably connected to the oil distribution pipe, and whose inner side wall is sealed with the outer side wall of the oil distribution pipe, and has a first position and a second position. When it is in the first position, it closes the oil inlet hole, and when it is in the second position, it opens the oil inlet hole; and

[0013] an elastic member, which is sleeved on the oil distribution pipe, and whose two ends are respectively connected to the oil distribution pipe and the sliding sleeve, and which has a tendency to move the sliding sleeve from the first position to the second position in a natural state;

[0014] Wherein, during the process of the separation plate descending, the separation plate pushes the sliding sleeve from the first position to the second position to open the oil inlet hole.

[0015] Furthermore, the opening and closing structure further comprises:

[0016] a limit block, which is sleeved on the oil distribution pipe and located above the sliding sleeve, and is fixedly connected to the oil distribution pipe, and the limit block contacts the sliding sleeve to limit the sliding sleeve to the first position; and

[0017] A support block is sleeved on the oil distribution pipe and is located below the sliding sleeve. The support block is fixedly connected to the oil distribution pipe. Two ends of the elastic member are respectively in contact with the support block and the sliding sleeve.

[0018] Furthermore, the separation plate is provided with a first water return hole corresponding one-to-one to the first through hole, the first end of the first water return hole is connected to the first through hole, and the second end downwardly penetrates the separation plate, so that when the first blocking part is inserted into the first through hole, the water blocked in the first through hole can flow out through the first water return hole.

[0019] Furthermore, the top of the separation plate gradually becomes lower from the outside to the inside.

[0020] Furthermore, the top of the first blocking portion is matched with the top of the separation plate.

[0021] In a second aspect, the present invention provides a sewage treatment device, comprising a separation tank as described above.

[0022] In a third aspect, the present invention provides a waste mineral oil resource processing system, comprising the above-mentioned sewage treatment device.

[0023] Beneficial effects of the present invention:

[0024] The separation tank, sewage treatment device and waste mineral oil resource treatment system provided by the present invention can descend together with the descending liquid level of the water in the tank body through the separation plate, and finally separate the waste mineral oil and water in the separation tank, so that the non-mineral oil and water in the separation tank can be quickly separated, thereby improving the separation efficiency. At the same time, after the waste mineral oil and water in the separation tank are completely separated, less waste mineral oil remains on the water surface, thereby improving the separation effect. Moreover, it is not necessary to drain the water in the tank body every time, and the purpose of separating the waste mineral oil therein can be achieved, thereby reducing the amount of waste mineral oil taken away due to draining the water in the tank body and saving resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0026] Figure 1 A three-dimensional view of a separation tank provided in one embodiment of the present invention;

[0027] Figure 2 for Figure 1 The three-dimensional view of the internal structure of the separation tank shown (when the separation plate does not conflict with the support seat);

[0028] Figure 3 for Figure 2 An enlarged view of section A of the separation tank is shown;

[0029] Figure 4 for Figure 1 A top view of the separation tank is shown;

[0030] Figure 5 for Figure 4 The cross-sectional view in the BB direction shown (when the separation plate is in conflict with the support seat);

[0031] Figure 6 for Figure 5 An enlarged view of portion D of the separation tank is shown;

[0032] Figure 7 for Figure 4The cross-sectional view in the CC direction shown (when the separation plate is in conflict with the support seat);

[0033] Figure 8 for Figure 7 An enlarged view of section E of the separator tank is shown.

[0034] Reference numerals:

[0035] 100, tank body; 110, liquid inlet; 120, liquid outlet; 210, separation plate; 211, first through hole; 212, first water return hole; 213, second through hole; 214, second water return hole; 215, third through hole; 216, third water return hole; 220, support seat; 221, first blocking part; 222, guide rod; 230, oil distribution pipe; 231, oil inlet; 241, sliding sleeve; 201, third blocking part; 242, elastic member; 243, limit block; 244, support block; 310, screw rod; 320, slider; 321, second blocking part; 330, motor. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0037] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0038] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0040] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0042] like Figure 1-8 As shown, the present invention provides a separation tank, a sewage treatment device and a waste mineral oil resource treatment system, including a tank body 100, the tank body 100 is provided with a liquid inlet 110 and a liquid outlet 120, the liquid inlet 110 is connected to and communicated with a liquid inlet pipe, the liquid outlet 120 is connected to and communicated with a water outlet pipe, and a separation component is arranged in the tank body 100, the separation component includes a separation plate 210, a support seat 220, an oil distribution pipe 230 and an opening and closing structure.

[0043] Among them, the separation plate 210 is slidably arranged in the tank body 100, the outer peripheral wall of the separation plate 210 is sealed with the inner wall of the tank body 100, a plurality of first through holes 211 are arranged on the separation plate 210, and the average density of the separation plate 210 is less than the density of water and greater than the density of waste mineral oil.

[0044] Specifically, the density of water is about 1 g / cm³, and the density of waste mineral oil is about 0.8 g / cm³, so preferably, the average density of the separation plate 210 is set at 0.9 g / cm³.

[0045] The support seat 220 is disposed in the tank body 100 and below the separation plate 210 . The support seat 220 is fixedly connected to the tank body 100 . A first blocking portion 221 corresponding to the first through hole 211 and used to block the first through hole 211 is disposed on the top of the support seat 220 .

[0046] Specifically, a plurality of guide rods 222 are disposed on the top of the support seat 220 , and the separation plate 210 is sleeved on the guide rods 222 and slidably connected to the guide rods 222 , thereby achieving the purpose of being slidably connected to the tank body 100 .

[0047] The first end of the oil distribution pipe 230 extends into the tank body 100 and extends upward along the axis direction of the tank body 100, and the second end extends outside the tank body 100. Preferably, the oil distribution pipe 230 is L-shaped. Preferably, the first end of the oil distribution pipe 230 is coaxially arranged with the tank body 100. The oil distribution pipe 230 is fixedly connected to the tank body 100, and an oil inlet hole 231 is arranged on the oil distribution pipe 230, and the oil inlet hole 231 is located above the support seat 220.

[0048] The opening and closing structure is disposed on the oil distribution pipe 230 , and the opening and closing structure has an open state in which the oil inlet hole 231 remains unobstructed, and a closed state in which the oil inlet hole 231 remains disconnected.

[0049] Among them, as the liquid level of water in the tank body 100 drops, the separation plate 210 drops to a position that contacts the support seat 220, so that the first blocking portion 221 is inserted into the first through hole 211 to separate the waste mineral oil and water in the tank body 100. At the same time, the separation plate 210 converts the opening and closing structure from a closed state to an open state to open the oil inlet hole 231, so that the waste mineral oil above the separation plate 210 can enter the oil distribution pipe 230 through the oil inlet hole 231.

[0050] Specifically, when in use, waste material (i.e. waste mineral oil containing a large amount of water) enters the tank body 100 through the liquid inlet pipe. The waste mineral oil in the waste material floats upward through the first through hole 211, and the water flows downward through the first through hole 211, thereby achieving the purpose of stratification. After the stratification is completed, since the average density of the separation plate 210 is between that of the waste mineral oil and that of water, the separation plate 210 will stay between the waste mineral oil and the water and be located above the support seat 220.

[0051] Afterwards, the water in the tank body 100 is extracted through the water outlet pipe and directed to the target equipment (for example, sewage purification equipment). As the liquid level of the water in the tank body 100 drops, the separation plate 210 drops accordingly. When the separation plate 210 drops to a position that conflicts with the support seat 220, the first blocking portion 221 is inserted into the first through hole 211 to separate the waste mineral oil and water in the tank body 100. At the same time, the separation plate 210 converts the opening and closing structure from a closed state to an open state to open the oil inlet hole 231, so that the waste mineral oil above the separation plate 210 can enter the oil distribution pipe 230 through the oil inlet hole 231 and finally be discharged through the oil outlet pipe and directed to the target equipment (for example, waste mineral oil recovery equipment, waste mineral oil distillation equipment, etc.).

[0052] Therefore, the purpose of separating the waste mineral oil therein can be achieved without draining all the water in the tank body 100 every time, thereby reducing the amount of waste mineral oil taken away by draining all the water in the tank body 100 and saving resources.

[0053] Preferably, the top of the separation plate 210 gradually becomes lower from the outside to the inside, so that the waste mineral oil flows along the top of the separation plate 210 into the oil inlet hole 231. For example, the top of the separation plate 210 is in a concave spherical shape, a trumpet shape, etc.

[0054] Preferably, the top of the first blocking portion 221 is matched with the top of the separation plate 210 so that after the separation plate 210 contacts the support seat 220 , a smooth curved surface or plane is formed on the top of the separation plate 210 , thereby facilitating the waste mineral oil to flow into the oil distribution pipe 230 .

[0055] Preferably, the separation plate 210 is provided with a first water return hole 212 corresponding one-to-one to the first through hole 211, the first end of the first water return hole 212 is connected to the first through hole 211, and the second end downwardly penetrates the separation plate 210, so that when the first blocking portion 221 is inserted into the first through hole 211, the water blocked in the first through hole 211 can flow out through the first water return hole 212.

[0056] The separation tank provided in the present embodiment can descend together with the descending liquid level of the water in the tank body 100 through the separation plate 210, and finally separate the waste mineral oil and water in the separation tank 0, so that the non-mineral oil and water in the separation tank can be quickly separated, thereby improving the separation efficiency. At the same time, after the waste mineral oil and water in the separation tank are completely separated, less waste mineral oil remains on the water surface, thereby improving the separation effect. Moreover, there is no need to drain the water in the tank body every time, and the purpose of separating the waste minerals therein can be achieved, thereby reducing the amount of waste mineral oil taken away due to draining the water in the tank body, thereby saving resources.

[0057] In one embodiment, the opening and closing structure includes a sliding sleeve 241 and an elastic member 242 .

[0058] The sleeve 241 is sleeved on the oil distribution pipe 230 and is slidably connected to the oil distribution pipe 230, and the inner side wall of the sleeve 241 is sealed with the outer side wall of the oil distribution pipe 230. The sleeve 241 has a first position and a second position. When the sleeve 241 is in the first position, the sleeve 241 closes the oil inlet hole 231. When the sleeve 241 is in the second position, the sleeve 241 opens the oil inlet hole 231.

[0059] Preferably, a third sealing portion 201 is provided on the top of the sleeve 241, and the top of the third sealing portion 201 is matched with the top of the separation plate 210, that is, when the separation plate 210 conflicts with the sleeve 241, the top of the third sealing portion 201 is flush with the top of the separation plate 210, which not only facilitates the waste mineral oil to flow to the oil inlet hole 231, but also ensures that only the oil above the separation plate can enter the oil distribution pipe 230 through the oil inlet hole 231, thereby achieving the purpose of preventing water from entering the separation pipe 230.

[0060] A third through hole 215 cooperating with the third blocking portion 201 is provided on the separation plate 210, and a third water return hole 216 is provided at the third through hole 215. The first end of the third water return hole 216 is connected to the third through hole 215, and the second end downwardly penetrates the separation plate 210, so that when the third blocking portion 201 is inserted into the third through hole 215, the water blocked in the third through hole 215 can flow out through the third water return hole 216.

[0061] The elastic member 242 is sleeved on the oil distribution pipe 230, and the two ends of the elastic member 242 are respectively connected to the oil distribution pipe 230 and the sliding sleeve 241, and in a natural state, the elastic member 242 has a tendency to move the sliding sleeve 241 from the first position to the second position. Specifically, in this embodiment, the elastic member 242 is a spring.

[0062] In the process of the separation plate 210 descending, the separation plate 210 pushes the sliding sleeve 241 from the first position to the second position to open the oil inlet hole 231 .

[0063] Specifically, the opening and closing structure further includes a limiting block 243 and a supporting block 244 .

[0064] The limit block 243 is sleeved on the oil distribution pipe 230 and is located above the sliding sleeve 241. The limit block 243 is fixedly connected to the oil distribution pipe 230, and the limit block 243 abuts against the sliding sleeve 241 to limit the sliding sleeve 241 to the first position. Preferably, the limit block 243 and the sliding sleeve 241 are in contact with each other on opposite sides. Preferably, the top of the limit block 243 gradually increases from the outside to the inside, so that the waste mineral oil flows along the top of the limit block 243. For example, the top of the limit block 243 is convexly spherical, trumpet-shaped, etc.

[0065] The support block 244 is sleeved on the oil distribution pipe 230 and is located below the sliding sleeve 241 . The support is fixedly connected to the oil distribution pipe 230 . Both ends of the elastic member 242 abut against the support block 244 and the sliding sleeve 241 respectively.

[0066] The opening and closing structure provided in this embodiment has a simple structure and a reasonable design. The opening and closing structure can be switched from a closed state to an open state by lowering the separation plate 210 to a position in contact with the support seat 220, and the operation is simple.

[0067] However, in the separation tank, sewage treatment device and waste mineral oil resource treatment system, during the separation of waste mineral oil and water, both waste mineral oil and water can only flow through the first through hole 211 on the separation plate 210, resulting in poor separation efficiency and effect of waste mineral oil and water. Therefore, in one embodiment, a lifting component is further included, which is used to drive the separation plate 210 to move up and down.

[0068] Before the waste enters the tank 100, the lifting assembly drives the separation plate 210 to the top of the inner side of the tank 100, so as to facilitate the separation of the waste mineral oil and water in the waste in the tank 100. After the separation is completed, the lifting assembly drives the separation plate 210 to descend. When the separation plate 210 descends to the junction of the waste mineral oil and water, the separation plate 210 finally stays at the junction of the waste mineral oil and water under the action of buoyancy, and can eventually descend synchronously with the drop in the water level.

[0069] Specifically, the driving assembly includes a screw rod 310 , a slider 320 and a motor 330 .

[0070] The screw rod 310 is disposed in the tank body 100 and is rotatably connected to the tank body 100. The slider 320 is disposed in the tank body 100 and is located below the separation plate 210, and the slider 320 is slidably connected to the tank body 100. Specifically, the slider 320 is sleeved on the guide rod 222 and is slidably connected to the guide rod 222. The slider 320 is sleeved on the screw rod 310 and is threadedly connected to the screw rod 310. The motor 330 is fixedly disposed on the tank body 100, and the motor 330 is transmission-connected to the screw rod 310.

[0071] When in use, the motor 330 drives the screw rod 310 to rotate forward, thereby driving the slider 320 to rise through the screw rod 310, and then pushing the separation plate 210 to rise through the slider 320. The motor 330 drives the screw rod 310 to rotate in the opposite direction, thereby driving the slider 320 to descend and move to a position where its top is flush with the top of the support seat 220 or is located below the top of the support seat. Under the action of gravity, the separation plate 210 descends. When the separation plate 210 descends to the junction of the waste mineral oil and water, under the action of buoyancy, the separation plate 210 finally stays at the junction of the waste mineral oil and water, and can eventually descend synchronously with the drop in water level.

[0072] The driving assembly in this embodiment has a simple structure and a reasonable design, and will not affect the synchronous descent of the separation plate 210 as the water level drops.

[0073] Preferably, the separation plate 210 is provided with a second through hole 213 for the screw rod 310 to pass through, and the top of the slider 320 is provided with a second blocking portion 321 for blocking the second through hole 213. Preferably, the top of the second blocking portion 321 is adapted to the top of the separation plate 210, and when the separation plate 210 is in conflict with the support seat 220, the top of the second blocking portion 321 is flush with the top of the separation plate 210, so that the waste mineral oil can flow to the oil inlet hole 231.

[0074] Preferably, a second water return hole 214 is provided at the second through hole 213, and the first end of the second water return hole 214 is connected to the second through hole, and the second end downwardly passes through the separation plate 210, so that when the second blocking portion 321 is inserted into the second through hole 213, the water blocked in the second through hole 213 can flow out through the second water return hole 214.

[0075] In one embodiment, the present invention further provides a sewage treatment device, comprising the separation tank described in any of the above embodiments, and also comprising sewage purification equipment.

[0076] When in use, the sewage discharged from the separation tank through the outlet pipe is introduced into the sewage purification equipment through the pipeline for sewage purification, and is discharged after reaching the discharge standard.

[0077] In one embodiment, the present invention further provides a waste mineral oil resource processing system, comprising the sewage treatment equipment in the above embodiment, and also comprising a waste mineral oil recovery device.

[0078] When in use, the waste mineral oil discharged from the separation tank through the oil distribution pipe 230 is introduced into the waste mineral oil recovery equipment through the oil outlet pipe, thereby achieving the purpose of resource recycling of the waste mineral oil.

[0079] In the description of the present invention, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A separation tank, comprising a tank body (100), wherein the tank body (100) is provided with a liquid inlet (110) and a liquid outlet (120), wherein the liquid inlet (110) is connected to and communicates with a liquid inlet pipe, and the liquid outlet (120) is connected to and communicates with a water outlet pipe, wherein: A separation component is arranged in the tank body (100), and the separation component comprises: A separation plate (210) is slidably disposed in the tank body (100), its outer peripheral wall is sealed with the inner wall of the tank body (100), a plurality of first through holes (211) are disposed thereon, and its average density is less than the density of water and greater than the density of waste mineral oil; a support seat (220), which is arranged in the tank body (100) and below the separation plate (210), and is fixedly connected to the tank body (100), and has a first blocking portion (221) on its top that corresponds one-to-one with the first through hole (211) and is used to block the first through hole (211); An oil distribution pipe (230), a first end of which extends into the tank body (100) and extends upwards along the axis direction of the tank body (100), and a second end of which extends outside the tank body (100), and is fixedly connected to the tank body (100), and is provided with an oil inlet hole (231), and the oil inlet hole (231) is located above the support seat (220); and an opening and closing structure, which is arranged on the oil distribution pipe (230) and has an open state in which the oil inlet hole (231) remains unobstructed, and a closed state in which the oil inlet hole (231) remains disconnected; As the liquid level of the water in the tank body (100) decreases, the separation plate (210) decreases to a position where it contacts the support seat (220), so that the first blocking portion (221) is inserted into the first through hole (211) to separate the waste mineral oil and water in the tank body (100); at the same time, the separation plate (210) converts the opening and closing structure from a closed state to an open state to open the oil inlet hole (231), so that the waste mineral oil above the separation plate (210) can enter the oil distribution pipe (230) through the oil inlet hole (231); The opening and closing structure comprises: a sliding sleeve (241), which is sleeved on the oil distribution pipe (230) and is slidably connected to the oil distribution pipe (230), and whose inner side wall is sealed with the outer side wall of the oil distribution pipe (230), and has a first position and a second position. When it is in the first position, it closes the oil inlet hole (231), and when it is in the second position, it opens the oil inlet hole (231); and an elastic member (242) sleeved on the oil distribution pipe (230), with two ends of the elastic member being respectively connected to the oil distribution pipe (230) and the sliding sleeve (241), and having a tendency to move the sliding sleeve (241) from a first position to a second position in a natural state; Wherein, during the process of the separation plate (210) descending, the separation plate (210) pushes the sliding sleeve (241) from the first position to the second position, so as to open the oil inlet hole (231).

2. The separation tank according to claim 1, characterized in that: The opening and closing structure also includes: a limit block (243) sleeved on the oil distribution pipe (230) and located above the sliding sleeve (241), and fixedly connected to the oil distribution pipe (230), and the limit block (243) abuts against the sliding sleeve (241) to limit the sliding sleeve (241) to the first position; and A support block (244) is sleeved on the oil distribution pipe (230) and is located below the sliding sleeve (241). The support block (244) is fixedly connected to the oil distribution pipe (230). Two ends of the elastic member (242) are respectively in contact with the support block (244) and the sliding sleeve (241).

3. The separation tank according to any one of claims 1 to 2, characterized in that: The separation plate (210) is provided with first water return holes (212) corresponding one-to-one to the first through holes (211); a first end of the first water return hole (212) is in communication with the first through hole (211), and a second end of the first water return hole (212) passes downward through the separation plate (210), so that when the first blocking portion (221) is inserted into the first through hole (211), water blocked in the first through hole (211) can flow out through the first water return hole (212).

4. The separation tank according to claim 3, characterized in that: The top of the separation plate (210) gradually becomes lower from the outside to the inside.

5. The separation tank according to claim 4, characterized in that: The top of the first blocking portion (221) is matched with the top of the separation plate (210).

6. A sewage treatment device, characterized in that: The invention comprises a separation tank as described in any one of claims 1 to 5.

7. A waste mineral oil resource processing system, characterized in that: Including the sewage treatment device as described in claim 6.

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