Oil-containing wastewater treatment device and method based on low-temperature evaporation

Abstract

The application provides an oil-containing wastewater treatment equipment and method based on low-temperature evaporation, and belongs to the technical field of wastewater treatment. The equipment comprises, which are arranged in series, a demulsifier reaction tank, a polyaluminum chloride reaction tank and a polyacrylamide reaction tank, and oil-containing wastewater flows through the three reaction tanks to realize continuous and staged flocculation; a filter pressing device is communicated with a discharge port of the polyacrylamide reaction tank, and is internally provided with an arc-shaped filter residue assembly, a rotary residue scraping assembly and a filter pressing cleaning assembly, and the three assemblies are cooperated to form integrated operations of filtering, salvaging, filter pressing and cleaning; and a low-temperature evaporation machine is connected to a liquid outlet end of the filter pressing device. The application realizes continuous demulsification and flocculation treatment through the multi-tank series connection, and batch waiting is not needed; the filter pressing device automatically cleans flocculation materials while filter pressing, so that blockage is avoided and manual cleaning is not needed during shutdown. The overall process is closely connected, and the degree of automation is high, so that the oil-containing wastewater treatment efficiency and continuous production capacity are significantly improved, and the water quality after treatment can reach the recycling standard.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more specifically to an apparatus and method for treating oily wastewater based on low-temperature evaporation. Background Technology

[0002] Oily wastewater is a typical highly polluting wastewater from industrial production, containing large amounts of floating oil, emulsified oil, suspended particles, and ammonia nitrogen, among other pollutants. Direct discharge of such wastewater severely damages the aquatic ecosystem. Low-temperature evaporation-based oily wastewater treatment methods remove water and volatile impurities through low-energy evaporation, combined with demulsification, flocculation, filtration, and denitrification processes, achieving highly efficient oil-water separation. This allows the wastewater to meet recycling standards, combining environmental friendliness and economic efficiency, and has become an important development direction in this field.

[0003] Currently, the industry commonly combines demulsification and flocculation, filtration, low-temperature evaporation, anaerobic denitrification, and membrane separation processes. However, existing technologies still have significant shortcomings: In the demulsification and flocculation stage, most methods involve adding multiple agents sequentially in a single reaction tank, or setting up multiple tanks but lacking a reasonable process connection, which makes it impossible to achieve continuous flocculation treatment. The next batch can only be carried out after the previous batch is completed, which seriously affects the continuity of treatment.

[0004] In the filter press stage, existing filter press equipment has a single function, only able to achieve solid-liquid separation, and lacks integrated cleaning capabilities. Flocculated material easily adheres to the surface of the arc-shaped filter cake assembly, making it impossible to clean in real time. Over time, it gradually clogs the filter channels, leading to a decrease in filter press efficiency. Frequent shutdowns for manual cleaning are necessary, which is not only labor-intensive but also results in significant downtime, severely restricting the continuity and overall efficiency of wastewater treatment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for treating oily wastewater based on low-temperature evaporation, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: As a first aspect of the present invention, an oily wastewater treatment device based on low-temperature evaporation is provided, comprising a demulsifier reaction tank, a polyaluminum chloride reaction tank and a polyacrylamide reaction tank arranged in series, wherein the polyaluminum chloride reaction tank is located below the discharge side of the demulsifier reaction tank and the polyacrylamide reaction tank is located below the discharge side of the polyaluminum chloride reaction tank, and the oily wastewater flows by gravity through the three reaction tanks in sequence to achieve staged demulsification and flocculation treatment. A filter press is installed below one side of the polyacrylamide reaction tank and connected to the outlet of the polyacrylamide reaction tank. It is used to receive the flocculated wastewater and flocculents. The inlet end of the low-temperature evaporator is connected to the outlet end of the filter press. The filter press includes a separation box, an arc-shaped filter cake assembly installed inside the separation box for intercepting flocculants, a rotary scraper assembly positioned above the arc-shaped filter cake assembly for collecting flocculants on the arc-shaped filter cake assembly, and a filter press cleaning assembly installed above the separation box, which has two working states: the first state is to filter the impurities collected by the rotary scraper assembly, and the second state is to clean the impurities remaining after filtration.

[0007] As a second aspect of the present invention, a method for treating oily wastewater based on low-temperature evaporation is provided, comprising the following steps: S1: Oily wastewater is sequentially transported to a demulsifier reaction tank, a polyaluminum chloride reaction tank, and a polyacrylamide reaction tank for staged demulsification and flocculation reaction; S2: The flocculants and wastewater in the polyacrylamide reaction tank are transported to the filter press for filtration and removal of residual impurities. S3: Introduce the filtered wastewater into a low-temperature evaporator to remove moisture and volatile impurities; S4: The remaining wastewater after evaporation is transported to an anaerobic tower for denitrification treatment; S5: The denitrified wastewater is transported to the DTRO equipment for deep filtration to meet the standards for recycling.

[0008] The oily wastewater treatment device and method based on low-temperature evaporation provided by this invention have the following advantages compared with the prior art: 1. By sequentially conveying oily wastewater to a demulsifier reaction tank, a polyaluminum chloride reaction tank, and a polyacrylamide reaction tank, continuous flocculation treatment of oily wastewater is achieved. The flocculent is then conveyed to a filter press for filtration, improving the connection between each treatment process and increasing treatment efficiency. Furthermore, the filter press simultaneously filters the flocculent and cleans it in real time, achieving integrated filtration and cleaning functions. This eliminates the need for frequent shutdowns for manual cleaning, further improving wastewater treatment efficiency. 2. The filter press unit integrates filtration, sludge removal, filtration, and cleaning through its arc-shaped filter cake assembly, rotary scraper assembly, and filter press cleaning assembly. During operation, the arc-shaped filter cake assembly intercepts flocculents, the rotary scraper assembly actively collects impurities, and the filter press cleaning assembly operates in two modes. This improves the efficiency of impurity treatment and prevents impurities from clogging the equipment. The overall structural design enables continuous processing, reduces the number of downtime cleanings, and improves the continuity of equipment operation and processing capacity. 3. Utilizing the special design of the arc-shaped separation box and the vertical sliding of the lifting slider, the rotation trajectory of the arc-shaped scraper plate is matched with the arc-shaped filter plate, improving the retrieval accuracy. When disassembling, cleaning or replacing the arc-shaped filter plate, the arc-shaped scraper plate can be inserted into the inside of the U-shaped clamp, driving the detachable arc-shaped outer frame to move to the opening of the separation box, which facilitates the disassembly and cleaning of the arc-shaped filter assembly and further reduces the difficulty of maintenance. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A schematic diagram of the filter press apparatus of the present invention is shown; Figure 2 This diagram illustrates the installation structure of the rotary slag scraper assembly of the present invention. Figure 1 ; Figure 3 This diagram illustrates the installation structure of the rotary slag scraper assembly of the present invention. Figure 2 ; Figure 4 This diagram illustrates the installation structure of the rotary slag scraper assembly of the present invention. Figure 3 ; Figure 5 This diagram illustrates the installation structure of the rotary slag scraper assembly of the present invention. Figure 4 ; Figure 6 A schematic diagram of the structure of the filter press cleaning assembly of the present invention is shown. Figure 1 ; Figure 7 A schematic diagram of the structure of the filter press cleaning assembly of the present invention is shown. Figure 2 ; Figure 8 This diagram illustrates the installation structure of the filter press cleaning assembly of the present invention. Figure 3 ; Figure 9 This diagram illustrates the mounting structure of the locking and positioning assembly of the present invention. Figure 1 ; Figure 10 This diagram illustrates the mounting structure of the locking and positioning assembly of the present invention. Figure 2 ; Figure 11 This invention illustrates the present invention. Figure 10 Enlarged view of point A in the middle; Figure 12 This diagram shows the overall structure of the oily wastewater treatment equipment of the present invention. As shown in the figure: 1. Demulsifier reaction tank; 2. Polyaluminum chloride reaction tank; 3. Polyacrylamide reaction tank; 4. Filter press device; 41. Base; 42. Separation box; 421. Side wall guide groove; 422. Side cleaning port; 423. Box lifting drive rod; 424. Slag discharge guide plate; 44. Arc-shaped filter cake assembly; 441. Detachable arc-shaped outer frame; 442. Arc-shaped filter plate; 45. Rotary scraper assembly; 451. Lifting slider; 4511. Sealing baffle; 452. Scraper shaft; 453. Shaft connecting block; 454. Scraper telescopic rod; 456. Arc-shaped scraper blade; 457. Scraper drive motor; 46. ​​Filter press cleaning assembly; 461. Cross-box support frame; 4611. Limiting plate; 4612. Synchronous connecting rod; 462. Horizontal slide; 463. Pressure plate lifting rod; 464. Pressure plate hinge frame; 465. Sliding plate; 466. Pressure plate; 5. Low-temperature evaporator; 6. Locking and positioning assembly; 61. Inner wall fixing block; 62. Lifting support rod; 63. Lifting platform; 64. Rotating shaft; 65. Square transmission head; 66. U-shaped clamp; 67. Locking screw; 67. Square insertion hole; 7. Slag collection box. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] Example 1: Combination Figures 1-12 As shown, the oily wastewater treatment equipment based on low-temperature evaporation includes a demulsifier reaction tank 1, a polyaluminum chloride reaction tank 2, a polyacrylamide reaction tank 3, a filter press 4, and a low-temperature evaporator 5.

[0013] Specifically, the demulsifier reaction tank 1, the polyaluminum chloride reaction tank 2, and the polyacrylamide reaction tank 3 are connected in series. The polyaluminum chloride reaction tank 2 is located below the discharge side of the demulsifier reaction tank 1, and the polyacrylamide reaction tank 3 is located below the discharge side of both the polyaluminum chloride reaction tank 2 and the demulsifier reaction tank 1. Oily wastewater flows by gravity through the three reaction tanks sequentially, achieving staged demulsification and flocculation treatment. Each reaction tank is equipped with a stirring mechanism to agitate and mix the materials within.

[0014] The filter press 4 is located below one side of the polyacrylamide reaction tank 3 and is connected to the outlet of the polyacrylamide reaction tank 3. It is used to receive the flocculated wastewater and flocculants. The outlet of the filter press 4 is connected to the inlet of the low-temperature evaporator 5, so that the filtered wastewater is sent to the low-temperature evaporator 5 for further treatment.

[0015] The filter press device 4 includes a base 41 and a separation chamber 42 mounted on the base 41. An arc-shaped filter cake assembly 44 is installed inside the separation chamber 42, with its outer wall fitting against the cross-section of the inner wall of the separation chamber 42. A rotary scraper assembly 45 is located above the arc-shaped filter cake assembly 44 to collect the flocculent material on it. A filter press cleaning assembly 46 extending above the separation chamber 42 is also mounted on the base 41. This assembly has two working states: one is to filter the impurities collected by the rotary scraper assembly 45, and the other is to clean the impurities remaining after filtration.

[0016] Through the coordinated operation of the arc-shaped filter cake assembly 44, the rotary scraper assembly 45, and the filter press cleaning assembly 46, an integrated operation of filtration, retrieval, filter press, and cleaning is formed, avoiding the clogging of equipment by impurities and achieving continuous processing.

[0017] The arc-shaped filter assembly 44 includes a detachable arc-shaped outer frame 441, an arc-shaped filter plate 442, and a locking and positioning assembly 6. The detachable arc-shaped outer frame 441 is detachably installed inside the separation chamber 42, with its outer wall fitting snugly against the inner wall of the separation chamber 42. The arc-shaped filter plate 442 is inserted into the detachable arc-shaped outer frame 441, and the two are fixed together with screws, ensuring a seamless fit. The locking and positioning assembly 6 is installed inside the separation chamber 42 and is used to position or release the detachable arc-shaped outer frame 441. When the arc-shaped filter plate 442 becomes clogged or damaged, it can be quickly disassembled and replaced by releasing the locking and positioning assembly 6.

[0018] The rotary scraper assembly 45 includes a lifting slider 451, a scraper shaft 452, a shaft connecting block 453, a scraper telescopic rod 454, an arc-shaped scraper plate 456, and a scraper drive motor 457. The lifting slider 451 is located within the guide grooves 421 on the side walls of the separation box 42. The scraper shaft 452 is horizontally rotatably mounted on two lifting sliders 451. The scraper drive motor 457 is mounted on one of the lifting sliders 451, driving the scraper shaft 452 to rotate. The shaft connecting block 453 is fixed to the outside of the scraper shaft 452. One end of the scraper telescopic rod 454 is connected to the shaft connecting block 453, and the other end is fixed to the arc-shaped scraper plate 456. The arc-shaped scraper plate 456 has drainage holes, and its arc-shaped surface can fit against the concave surface of the arc-shaped filter plate 442.

[0019] In use, the scraper drive motor 457 drives the scraper shaft 452 to rotate, and the position of the arc-shaped scraper plate 456 is adjusted by the scraper telescopic rod 454 so that it fits against the concave surface of the arc-shaped screen plate 442 and slides along the arc-shaped screen plate 442 to completely scrape off and collect flocculent material.

[0020] The filter press cleaning assembly 46 includes a cross-chamber support frame 461, a horizontal slide block 462, a sliding plate 465, a pressure plate hinge frame 464, a pressure plate 466, and a drive adjustment assembly. The cross-chamber support frame 461 is mounted on the base 41 near the side cleaning port 422 of the separation chamber 42, with its top extending above the side cleaning port 422. The horizontal slide block 462 is fixed to the top of the cross-chamber support frame 461, and the sliding plate 465 is horizontally slidably mounted within the horizontal slide block 462. The pressure plate hinge frame 464 is connected below the sliding plate 465 via a pressure plate lifting rod 463 and can move up and down. The pressure plate 466 is rotatably mounted between the two pressure plate hinge frames 464, its width matching the arc-shaped scraper plate 456, and can pass through the side cleaning port 422 to fit against the arc-shaped scraper plate 456.

[0021] When in use, this component has two operating states: Filtration state: Drive the sliding plate 465 to move horizontally, and at the same time adjust the height and angle of the pressure plate 466 so that the pressure plate 466 fits with the arc-shaped scraper plate 456 to squeeze and dehydrate the collected flocs.

[0022] Cleaning status: Adjust the angle of the pressure plate 466 so that it slides along the surface of the arc-shaped scraper plate 456 to scrape off the impurities remaining after filtration into the slag collection box 7, thus achieving automatic cleaning.

[0023] The locking and positioning assembly 6 includes an inner wall fixing block 61, a lifting support rod 62, a lifting platform 63, a rotating shaft 64, a square transmission head 65, a U-shaped clamp 66, and a locking screw 67. The inner wall fixing blocks 61 are respectively installed on the inner walls of both sides of the separation box 42; the lifting support rod 62 is vertically installed on the top of the inner wall fixing block 61, and the lifting platform 63 is fixed at its top, allowing it to rise and fall under driving action. The rotating shaft 64 is vertically installed on the lifting platform 63, and the square transmission head 65 is fixed at its top. Grooves are provided at the bottom of both sides of the detachable arc-shaped outer frame 441, and the U-shaped clamp 66 is U-shaped and vertically penetrates the grooves. The locking screw 67 is rotatably installed on the top of the U-shaped clamp 66, and a square insertion hole 671 is provided at its bottom, which can be inserted and engaged with the square transmission head 65; a threaded groove is provided on the top wall of the groove, allowing the end of the locking screw 67 to engage with it. The arc-shaped scraper 456 can be inserted into the inside of the U-shaped clamp 66 and fit against it.

[0024] In use, the lifting platform 63 causes the square transmission head 65 to insert into or disengage from the square insertion hole 671 at the bottom of the locking screw 67. The rotating shaft 64 then drives the locking screw 67 to rotate, engaging or disengaging the locking screw 67 from the threaded groove, thereby positioning or releasing the detachable arc-shaped outer frame 441. When the arc-shaped filter assembly 44 needs to be disassembled, after releasing the positioning, the arc-shaped scraper plate 456 can move the detachable arc-shaped outer frame 441 out of the opening of the separation box 42, facilitating the replacement or cleaning of the arc-shaped filter plate 442.

[0025] The longitudinal section of the separation box 42 is arc-shaped. The lifting slider 451 is vertically slidably installed in the guide grooves 421 on both sides of the separation box 42, and its lifting is controlled by the box lifting drive rod 423. The arc-shaped scraper 456 can be inserted into the inside of the U-shaped clamp 66 and fits against it.

[0026] When the lifting slider 451 slides to the top of the side wall guide groove 421, the center of the arc of the arc-shaped filter plate 442 is located on the axis of the scraper shaft 452, and the height of the scraper shaft 452 is higher than the inner bottom wall of the side cleaning port 422.

[0027] When the lifting slider 451 slides to the bottom of the side wall guide groove 421, the center of the arc of the separation box 42 itself is located on the axis of the scraper shaft 452.

[0028] By using the vertical sliding of the arc-shaped lifting slider 451, the rotation trajectory of the arc-shaped scraper 456 is precisely matched with that of the arc-shaped filter plate 442, improving the retrieval accuracy. When it is necessary to disassemble or replace the arc-shaped filter plate 442, the arc-shaped scraper 456 can be inserted into the U-shaped clamp 66, which moves the detachable arc-shaped outer frame 441 to the opening of the separation box 42, facilitating the disassembly and assembly of the arc-shaped filter assembly 44 and reducing maintenance difficulty.

[0029] The slag collection box 7 is placed on the cross-box support frame 461, with its opening located below the side cleaning port 422. The bottom wall of the side cleaning port 422 is equipped with a slag discharge guide plate 424 to guide impurities into the slag collection box 7. The cross-box support frame 461 has sliding limit plates 4611 on both sides, which respectively fit against the sides of the slag collection box 7. The two limit plates 4611 are synchronously raised and lowered via a synchronous connecting rod 4612. The upper and lower ends of the side wall guide groove 421 have receiving cavities, and the top and bottom of the lifting slider 451 are equipped with sealing baffles 4511 that extend into the receiving cavities.

[0030] The slag collection box 7 works in conjunction with the slag discharge guide plate 424 to achieve precise collection of impurities and prevent scattering. The limiting plate 4611 not only positions the slag collection box 7 but also prevents impurities from splashing; the synchronous connecting rod 4612 facilitates the synchronous lifting and lowering of the limiting plate 4611 and makes it easy to disassemble the slag collection box 7. The sealing baffle 4511 seals the side wall guide groove 421 when the lifting slider 451 moves to prevent leakage. The pressure plate 466 can extend into the slag collection box 7 to compact impurities, improving the utilization rate of the slag collection box 7 and reducing the frequency of cleaning.

[0031] Example 2: The oily wastewater treatment method based on low-temperature evaporation provided by this invention includes the following steps: S1: Demulsification and flocculation treatment The oily wastewater was sequentially transported to a demulsifier reaction tank, a polyaluminum chloride reaction tank, and a polyacrylamide reaction tank for staged demulsification and flocculation reactions. The specific process is as follows: The oily wastewater is sent into the demulsifier reaction tank, demulsifier is added, and the mixture is stirred for 10-30 minutes. The wastewater in the demulsifier reaction tank is transferred to the polyaluminum chloride reaction tank, polyaluminum chloride is added, and the mixture is stirred for 5-15 minutes. Wastewater from the polyaluminum chloride reaction tank is transferred to the polyacrylamide reaction tank, polyacrylamide is added, and the mixture is stirred for 20-40 minutes to complete the demulsification and flocculation reaction.

[0032] The mass ratio of demulsifier, polyaluminum chloride, polyacrylamide to oily wastewater is 0.3:1.5:0.02:1000.

[0033] S2: Pressure filtration The flocculants and wastewater in the polyacrylamide reaction tank are transported together to the filter press device to filter the demulsified and flocculated wastewater to remove large particulate impurities. At the same time, residual impurities are cleaned in real time, realizing the integrated operation of filter press and cleaning.

[0034] S3: Low-temperature evaporation treatment The filtered wastewater is then introduced into a low-temperature evaporator (preferred model). The process involves removing water and some volatile impurities from wastewater through low-temperature evaporation.

[0035] S4: Anaerobic denitrification treatment The remaining wastewater after evaporation is transported to an external anaerobic tower, where the ammonia nitrogen content is reduced by the action of anaerobic bacteria and sludge.

[0036] S5: Deep Filtering Process The wastewater after anaerobic denitrification is transported to an external DTRO device for further filtration and purification, so that the effluent quality meets the standards for recycling.

[0037] The above steps enable continuous and automated treatment of oily wastewater without the need for manual intervention or shutdown for cleaning.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An oily wastewater treatment device based on low-temperature evaporation, characterized in that, include: The demulsifier reaction tank (1), polyaluminum chloride reaction tank (2) and polyacrylamide reaction tank (3) are connected in series. The polyaluminum chloride reaction tank (2) is located below the discharge side of the demulsifier reaction tank (1), and the polyacrylamide reaction tank (3) is located below the discharge side of the polyaluminum chloride reaction tank (2). The oily wastewater flows through the three reaction tanks by gravity in sequence to achieve graded demulsification and flocculation treatment. The filter press (4) is located below one side of the polyacrylamide reaction tank (3) and is connected to the outlet of the polyacrylamide reaction tank (3) for receiving the flocculated wastewater and flocs. The inlet end of the low-temperature evaporator (5) is connected to the outlet end of the filter press (4); The filter press device (4) includes a separation box (42), an arc-shaped filter cake assembly (44) installed inside the separation box (42) for intercepting flocculents; a rotary scraper assembly (45) located above the arc-shaped filter cake assembly (44) for collecting flocculents on the arc-shaped filter cake assembly (44); and a filter press cleaning assembly (46) installed above the separation box (42) with two working states: the first state is to filter the impurities collected by the rotary scraper assembly (45), and the second state is to clean the impurities remaining after filter press.

2. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 1, characterized in that, The arc-shaped filter assembly (44) includes a detachable arc-shaped outer frame (441), an arc-shaped filter plate (442), and a locking and positioning assembly (6); the detachable arc-shaped outer frame (441) is detachably installed in the separation box (42); the arc-shaped filter plate (442) is inserted into the detachable arc-shaped outer frame (441), and the two are in close contact without gaps; the locking and positioning assembly (6) is used to position or release the detachable arc-shaped outer frame (441).

3. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 2, characterized in that, The rotary scraper assembly (45) includes a lifting slider (451), a scraper shaft (452), an arc-shaped scraper plate (456), and a scraper drive motor (457). The lifting slider (451) is located in the side wall guide grooves (421) on both sides of the separation box (42). The scraper shaft (452) is rotatably mounted on the two lifting sliders (451). The scraper drive motor (457) drives the scraper shaft (452) to rotate. The arc-shaped scraper plate (456) is connected to the scraper shaft (452), and its arc surface can fit against the concave surface of the arc-shaped filter plate (442) for scraping and collecting flocculents.

4. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 3, characterized in that, The filter press cleaning assembly (46) includes a cross-box support frame (461), a sliding plate (468), a pressure plate (466), and a drive adjustment assembly; the cross-box support frame (461) is installed on one side of the side cleaning port (422) of the separation box (42); the sliding plate (468) is horizontally slidably installed on the top of the cross-box support frame (461); the pressure plate (466) is connected below the sliding plate (468) and can pass through the side cleaning port (422) to fit against the arc-shaped scraper plate (456); the drive adjustment assembly is used to control the movement of the sliding plate (468) and the angle adjustment of the pressure plate (466).

5. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 2, characterized in that, The locking and positioning assembly (6) includes an inner wall fixing block (61), a lifting platform (63), a rotating shaft (64), a square transmission head (65), a U-shaped clamp (66), and a locking screw (67); the inner wall fixing block (61) is installed on the inner wall of the separation box (42); the lifting platform (63) is installed on the inner wall fixing block (61) in a lifting manner; the rotating shaft (64) is installed on the lifting platform (63), and a square transmission head (65) is provided on its top; the U-shaped clamp (66) is movably inserted into the groove of the detachable arc-shaped outer frame (441); the locking screw (67) is rotatably installed on the top of the U-shaped clamp (66), and a square insertion hole (671) is provided at its bottom for insertion into the square transmission head (65), and the end of the locking screw (67) can engage with the threaded groove in the groove; the arc-shaped scraper (456) can be inserted into the inside of the U-shaped clamp (66) and fit against it.

6. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 3, characterized in that, The longitudinal section of the separation box (42) is arc-shaped; the lifting slider (451) is vertically slidably installed in the side wall guide groove (421); when the lifting slider (451) slides to the top of the side wall guide groove (421), the center of the arc of the arc-shaped filter plate (442) is located on the axis of the scraper shaft (452); when the lifting slider (451) slides to the bottom of the side wall guide groove (421), the center of the arc of the separation box (42) is located on the axis of the scraper shaft (452).

7. The oily wastewater treatment equipment based on low-temperature evaporation according to claim 1, characterized in that, It also includes a slag collection box (7), which is placed on the cross-box support frame (461) and located below the side cleaning port (422); the bottom wall of the side cleaning port (422) is provided with a slag discharge guide plate (424); the cross-box support frame (461) is provided with a sliding limit plate (4611) on both sides, which is used to position the slag collection box (7) and guide the material.

8. A method for treating oily wastewater based on low-temperature evaporation, using the equipment described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1: The oily wastewater is sequentially transported to the demulsifier reaction tank (1), the polyaluminum chloride reaction tank (2), and the polyacrylamide reaction tank (3) for staged demulsification and flocculation reaction; S2: The flocculants and wastewater in the polyacrylamide reaction tank (3) are transported to the filter press (4) for filter pressing and cleaning of residual impurities at the same time; S3: Introduce the filtered wastewater into a low-temperature evaporator (5) to remove moisture and volatile impurities; S4: The remaining wastewater after evaporation is transported to an anaerobic tower for denitrification treatment; S5: The denitrified wastewater is transported to the DTRO equipment for deep filtration to meet the standards for recycling.

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