Low-energy-consumption coal chemical industry high-salinity wastewater salt separation and crystallization device and method

Abstract

The invention discloses a low-energy-consumption coal chemical industry high-salinity wastewater salt separation and crystallization device and method. The pretreatment mechanism is arranged in the treatment box and comprises a stirring unit which is fixed at the top of the treatment box, extends to an inner cavity of the treatment box and is used for fully mixing the high-salinity wastewater with a coagulant to promote a flocculation reaction; the detachable filter plate is vertically arranged in an inner cavity of the treatment box and divides the inner cavity of the treatment box into a precipitation cavity and a filter cavity; the filtering assembly is mounted on the side wall of the treatment box, the water inlet end communicates with the filtering cavity, and a purified water outlet is formed in the bottom of the side wall of the filtering assembly; the evaporation crystallizer is communicated with the purified water outlet of the filtering assembly through a conveying pipeline and is used for performing salt separation and crystallization on the finely filtered high-salt wastewater. According to the device, multi-stage efficient treatment on high-salinity wastewater is realized, the wastewater purification effect and the salt separation crystallization efficiency are effectively improved, and meanwhile, the maintenance of the filter plate and the cleaning of precipitates are facilitated.

Description

Technical Field

[0001] This application relates to the field of coal chemical equipment technology, and specifically to a low-energy coal chemical high-salt wastewater desalination crystallization device and method. Background Technology

[0002] Against the backdrop of ongoing global energy restructuring and the booming development of the chemical industry, the coal chemical industry, with its advantages of high resource conversion efficiency and diverse product range, is experiencing rapid growth. However, the coal chemical production process inevitably generates large amounts of high-salinity wastewater, which has become a key environmental issue restricting the sustainable development of this industry.

[0003] The composition of high-salinity wastewater from coal chemical industries is extremely complex. Besides containing large amounts of major salts such as sodium chloride and sodium sulfate, it also contains various trace metal salts and a wide variety of organic pollutants. These pollutants have different chemical properties and physical states, making wastewater treatment extremely difficult. Direct discharge without proper treatment will cause serious harm to the surrounding ecological environment. When wastewater enters the soil, it leads to soil salinization, damages soil structure, reduces soil fertility, severely affects the normal growth of crops, and may even cause desertification. When discharged into water bodies, it alters the chemical properties of the water, destroys the habitat of aquatic organisms, and triggers a series of chain reactions of ecological and environmental problems. Furthermore, the wastewater contains a large amount of recoverable salts; direct discharge not only results in a huge waste of resources but also increases the production costs of enterprises.

[0004] In the salt separation and crystallization process of high-salt wastewater from coal chemical industry, wastewater pretreatment is a crucial initial step, directly impacting the stability of subsequent treatment processes and the quality of salt separation and crystallization. However, uneven mixing of coagulants and wastewater is a significant problem during pretreatment, leading to incomplete flocculation and difficulty in effectively settling large amounts of suspended solids and colloids. These unremoved impurities, upon entering the subsequent evaporation and crystallization process, rapidly form a dense scale layer on the surface of the evaporation equipment. This scale layer significantly reduces the heat transfer efficiency of the equipment, requiring more energy for evaporation and increasing operating costs. Furthermore, the continuous accumulation of scale can frequently cause equipment failures, shortening equipment lifespan and increasing maintenance and replacement costs. On the other hand, traditional pretreatment technologies struggle to efficiently remove organic pollutants from the wastewater. Organic components in high-salt wastewater from coal chemical industry interfere with the salt crystallization process, resulting in inconsistent crystal growth rates, uneven crystal size, and reduced purity, significantly diminishing the salt separation effect and failing to meet the requirements for resource utilization of high-salt wastewater. Summary of the Invention

[0005] This application provides a low-energy coal chemical high-salt wastewater desalination crystallization device and method, which solves the problems mentioned in the background art.

[0006] In a first aspect, embodiments of this application provide a low-energy coal chemical high-salt wastewater desalination crystallization device, comprising:

[0007] A treatment tank is used to receive and pre-treat high-salinity wastewater. A pre-treatment mechanism, located within the treatment tank, includes: a stirring unit fixed to the top of the treatment tank and extending into its inner cavity, used to fully mix the high-salinity wastewater with the coagulant to promote flocculation; and a detachable filter plate vertically installed within the treatment tank, dividing the inner cavity into a sedimentation chamber and a filtration chamber, used to intercept large suspended particles generated by the flocculation reaction, thus initially purifying the high-salinity wastewater entering the filtration chamber.

[0008] A filter assembly is installed on the side wall of the treatment tank, with its inlet end connected to the filter chamber for fine filtration of high-salt wastewater in the filter chamber. A clean water outlet is provided at the bottom of the side wall of the filter assembly.

[0009] The evaporator crystallizer is connected to the purified water outlet of the filter assembly via a delivery pipeline and is used to perform salt separation and crystallization on the finely filtered high-salt wastewater.

[0010] In conjunction with the first aspect, in one possible implementation, the pretreatment mechanism further includes a scraping component;

[0011] The scraping assembly includes a second motor, a rotating rod, a first gear, a second gear, a threaded rod, a spiral discharge shaft, and a scraper.

[0012] The second motor is mounted on the side wall of the processing box;

[0013] One end of the rotating rod is connected to the output end of the second motor, and the other end extends to the sedimentation chamber of the processing tank;

[0014] One end of the spiral discharge shaft is connected to the end of the rotating rod away from the second motor, and the other end is connected to the outlet of the processing box for discharging the sediment at the bottom of the sedimentation chamber;

[0015] The first gear is fixedly connected to the outer wall of the rotating rod and is located outside the processing box; the second gear meshes with the first gear.

[0016] The threaded rod is fixedly connected to the second gear and extends into the sedimentation chamber;

[0017] The scraper is threadedly connected to the threaded rod via a threaded sleeve and is used to clean the surface of the removable filter plate.

[0018] In conjunction with the first aspect, in one possible implementation, the top of the removable filter plate is provided with a groove, and the top of the scraper is provided with a slider that slides in cooperation with the groove.

[0019] In conjunction with the first aspect, in one possible implementation, the low-energy coal chemical high-salt wastewater desalination crystallization device further includes a housing; the first gear and the second gear are both disposed within the housing; the second motor is mounted on the outer wall of the housing, and its output end extends into the inner cavity of the housing.

[0020] In conjunction with the first aspect, in one possible implementation, the outlet of the processing box is provided with a cleaning pipe, and the cleaning pipe is provided with a valve.

[0021] In conjunction with the first aspect, in one possible implementation, the filtration assembly includes a pump body, a filter cartridge, and an ultrafiltration membrane assembly; the pump body is disposed on the top of the treatment tank, and its input end is connected to the filter chamber through a first connecting pipe; the filter cartridge is fixed to the outer wall of the treatment tank, and its inlet is connected to the output end of the pump body through a second connecting pipe; the ultrafiltration membrane assembly is detachably disposed inside the filter cartridge for fine filtration of the pre-purified high-salt wastewater; a clean water outlet is provided at the bottom of the side wall of the filter cartridge, and a drain pipe is provided in the middle of its side wall for cleaning impurities on the ultrafiltration membrane assembly.

[0022] In conjunction with the first aspect, in one possible implementation, the low-energy coal chemical high-salt wastewater desalination crystallization device further includes a membrane self-cleaning mechanism; the membrane self-cleaning mechanism includes a third motor, a connecting shaft, and a cleaning plate; the third motor is installed at the bottom of the filter cartridge, and its output end extends into the filter cartridge and is connected to the connecting shaft; the cleaning plate is fixedly connected to the outer wall of the connecting shaft and contacts the surface of the ultrafiltration membrane module.

[0023] In conjunction with the first aspect, in one possible implementation, the ultrafiltration membrane assembly includes a first filter membrane and a second filter membrane; both the first filter membrane and the second filter membrane are fixedly disposed inside the filter cartridge and are spaced apart along the height direction of the filter cartridge; the first filter membrane is located above the second filter membrane, and the pore size of the first filter membrane is larger than the pore size of the second filter membrane; two cleaning plates are provided; the two cleaning plates are respectively in contact with the surfaces of the first filter membrane and the second filter membrane.

[0024] In conjunction with the first aspect, in one possible implementation, the stirring unit includes a first motor, a stirrer, and a mounting plate; the mounting plate is fixed to the top of the processing tank; the first motor is mounted on the top of the processing tank; the stirrer is connected to the output end of the first motor and extends to the sedimentation chamber.

[0025] Secondly, embodiments of this application provide a low-energy coal chemical high-salt wastewater desalination crystallization method, including the low-energy coal chemical high-salt wastewater desalination crystallization apparatus described in the first aspect or any one of the first aspects, the method further including:

[0026] High-salt wastewater is fed into the sedimentation chamber of the treatment tank, coagulant is added, and forced mixing and flocculation are carried out through the stirring unit;

[0027] After flocculation, the high-salt wastewater passes through a detachable filter plate to intercept large suspended solids, and the preliminarily purified high-salt wastewater enters the filtration chamber.

[0028] The high-salt wastewater that has been initially purified is further filtered by the filtration components to remove colloids and organic matter.

[0029] After fine filtration, the high-salt wastewater enters the evaporator crystallizer through a pipeline, where sodium chloride and sodium sulfate are separated and crystallized for recovery.

[0030] One or more technical solutions provided in the embodiments of this application have at least the following technical effects:

[0031] In this embodiment of the low-energy coal chemical high-salt wastewater desalination crystallization device, the high-salt wastewater enters the treatment tank. The stirring unit of the pretreatment mechanism thoroughly mixes the high-salt wastewater with the coagulant to promote flocculation. Large suspended particles generated by the reaction are intercepted by the detachable filter plate, thus initially purifying the high-salt wastewater entering the filtration chamber. Subsequently, the filter assembly performs fine filtration on the high-salt wastewater, and the purified water enters the evaporator crystallizer for salt separation crystallization. This device achieves efficient pretreatment and fine filtration through a reasonable structure, effectively removing impurities and preventing them from entering the subsequent evaporation crystallization process and causing equipment scaling, thereby reducing the energy consumption of subsequent evaporation crystallization and reducing enterprise operating costs. At the same time, the efficient removal of impurities and organic pollutants improves the salt separation crystallization effect, resulting in a consistent crystal growth rate and increased purity after salt separation, meeting the requirements for the resource utilization of high-salt wastewater. In addition, the detachable filter plate facilitates maintenance and allows for timely cleaning of intercepted impurities, ensuring stable operation of the device and providing a reliable solution for the low-energy and efficient treatment of high-salt wastewater from coal chemical industry. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the structure of the low-energy coal chemical high-salt wastewater desalination crystallization device provided in the embodiments of this application (view 1);

[0034] Figure 2 A second viewpoint of the structural schematic diagram of the low-energy coal chemical high-salt wastewater desalination crystallization device provided in the embodiments of this application;

[0035] Figure 3 This is a schematic diagram of the structure of the filter cartridge provided in an embodiment of this application;

[0036] Figure 4 A schematic diagram of the structure of the third motor provided in the embodiments of this application;

[0037] Figure 5 A cross-sectional view of the processing box provided in an embodiment of this application;

[0038] Figure 6 for Figure 5 Enlarged view of point A in the image.

[0039] Icons: 1-Processing box; 2-Pretreatment mechanism; 201-Mounting plate; 202-First motor; 203-Agitator; 204-Removable filter plate; 205-Housing; 206-Second motor; 207-Rotor; 208-Screw discharge shaft; 209-First gear; 210-Second gear; 211-Threaded rod; 212-Scraper; 3-Filter assembly; 301-Pump body; 302-First connecting pipe; 303-Second connecting pipe; 304-Filter cartridge; 305-Ultrafiltration membrane assembly; 4-Base plate; 5-Evaporator crystallizer; 6-Third motor; 7-Connecting shaft; 8-Cleaning plate; 9-Fixing frame; 10-Drain pipe; 11-Clean water outlet; 12-Slider; 13-Cleaning pipe. Detailed Implementation

[0040] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0042] This application provides a low-energy coal chemical high-salt wastewater desalination crystallization device, such as... Figures 1 to 6 As shown, the low-energy coal chemical high-salt wastewater desalination crystallization device includes:

[0043] Treatment tank 1 is used to receive and pretreat high-salinity wastewater. Pretreatment mechanism 2, located inside treatment tank 1, includes a stirring unit fixed to the top of treatment tank 1 and extending into its inner cavity, used to thoroughly mix the high-salinity wastewater with the coagulant to promote flocculation. A detachable filter plate 204 is vertically installed inside the treatment tank 1 and connected to the inner wall of treatment tank 1 via a detachable bracket, dividing the inner cavity of treatment tank 1 into a sedimentation chamber and a filtration chamber, used to intercept large suspended particles generated by the flocculation reaction, thus providing preliminary purification of the high-salinity wastewater entering the filtration chamber.

[0044] The filter assembly 3 is installed on the side wall of the treatment tank 1, and its inlet end is connected to the filter chamber for fine filtration of high-salt wastewater in the filter chamber. A clean water outlet 11 is provided at the bottom of the side wall of the filter assembly 3. The filter assembly 3 is installed on the side wall of the treatment tank 1 by a fixing bracket 9.

[0045] The evaporator crystallizer 5 is connected to the purified water outlet 11 of the filter assembly 3 via a conveying pipeline, and is used for salt separation and crystallization of the finely filtered high-salt wastewater. A base plate 4 is fixedly connected to the bottom of one side of the treatment tank 1, and the evaporator crystallizer 5 is fixedly connected to the top of the base plate 4.

[0046] It should be noted that, in the low-energy coal chemical high-salt wastewater desalination crystallization device of this application embodiment, the high-salt wastewater enters the treatment tank 1. The stirring unit of the pretreatment mechanism 2 thoroughly mixes the high-salt wastewater with the coagulant to promote flocculation reaction. The large particulate suspended matter generated by the reaction is intercepted by the detachable filter plate 204, thus initially purifying the high-salt wastewater entering the filtration chamber. Subsequently, the filter assembly 3 performs fine filtration on the high-salt wastewater, and the finely filtered water enters the evaporator crystallizer 5 for salt separation crystallization. This device achieves efficient pretreatment and fine filtration through a reasonable structure, effectively removing impurities and preventing impurities from entering the subsequent evaporation crystallization process and causing equipment scaling, thereby reducing the energy consumption of subsequent evaporation crystallization and reducing enterprise operating costs. At the same time, the efficient removal of impurities and organic pollutants can improve the salt separation crystallization effect, making the crystal growth rate after salt separation consistent and the purity higher, meeting the requirements for the resource utilization of high-salt wastewater. In addition, the detachable filter plate 204 is easy to maintain and can promptly clean the intercepted impurities, ensuring stable operation of the device and providing a reliable solution for low-energy and efficient treatment of coal chemical high-salt wastewater.

[0047] Specifically, the detachable filter plate 204 has a pore size of 0.5-1mm and a thickness of 5-8mm, and has sufficient strength to withstand the pressure of high-salt wastewater, while effectively intercepting large particulate suspended solids.

[0048] In this embodiment of the application, the pretreatment mechanism 2 further includes a scraping component.

[0049] The scraping assembly includes a second motor 206, a rotating rod 207, a first gear 209, a second gear 210, a threaded rod 211, a spiral discharge shaft 208, and a scraper 212.

[0050] The second motor 206 is installed on the side wall of the processing box 1.

[0051] One end of the rotating rod 207 is connected to the output end of the second motor 206, and the other end extends to the sedimentation chamber of the processing box 1.

[0052] One end of the spiral discharge shaft 208 is connected to the end of the rotating rod 207 away from the second motor 206, and the other end is connected to the outlet of the processing box 1, for discharging the sediment at the bottom of the sedimentation chamber.

[0053] The first gear 209 is fixedly connected to the outer wall of the rotating rod 207 and is located outside the processing box 1. The second gear 210 meshes with the first gear 209.

[0054] The threaded rod 211 is fixedly connected to the second gear 210 and extends into the sedimentation chamber.

[0055] The scraper 212 is threadedly connected to the threaded rod 211 via a threaded sleeve. The scraper 212 is parallel to and abuts against the surface of the removable filter plate 204 for cleaning the surface of the removable filter plate 204.

[0056] It should be noted that the second motor 206 is installed on the side wall of the treatment tank 1, and one end of the rotating rod 207 connected to its output end extends into the sedimentation chamber. The rotating rod 207 drives the spiral discharge shaft 208 to rotate, discharging the sediment at the bottom of the sedimentation chamber from the outlet of the treatment tank 1. At the same time, the first gear 209 located outside the treatment tank 1 on the outer wall of the rotating rod 207 rotates, driving the second gear 210 meshing with it to rotate. The threaded rod 211 connected to the second gear 210 rotates accordingly, and the scraper 212 threadedly connected to the threaded rod 211 moves along the threaded rod 211 under the action of the threaded sleeve, cleaning the surface of the removable filter plate 204. Therefore, the spiral discharge shaft 208 of this application can effectively discharge sediment, preventing it from accumulating in the sedimentation chamber and affecting the treatment effect; the scraper 212 can clean the surface of the removable filter plate 204 in a timely manner, avoiding impurities from clogging the filter plate, ensuring filtration efficiency, ensuring the quality of wastewater entering the subsequent treatment stage, and improving the operational stability and treatment effect of the entire low-energy coal chemical high-salt wastewater desalination crystallization device.

[0057] In this embodiment, the top of the detachable filter plate 204 is provided with a groove, and the top of the scraper 212 is provided with a slider 12 that slides in cooperation with the groove.

[0058] It should be noted that the sliding fit between the slider 12 and the groove provides precise guidance and stable support for the movement of the scraper 212, ensuring that the scraper 212 can move smoothly and steadily along the predetermined trajectory when cleaning the surface of the removable filter plate 204. This effectively avoids deviation or shaking of the scraper 212 during movement, improving the accuracy and efficiency of cleaning, and more thoroughly removing impurities from the surface of the filter plate, preventing impurity accumulation from affecting the filtration effect. At the same time, this sliding fit structure is simple and reliable, easy to install and maintain, reduces the failure rate of the device, and ensures the stable operation of the low-energy coal chemical high-salt wastewater desalination crystallization device.

[0059] In this embodiment, the low-energy coal chemical high-salt wastewater desalination crystallization device further includes a housing 205. A first gear 209 and a second gear 210 are both disposed within the housing 205. A second motor 206 is mounted on the outer wall of the housing 205, and its output end extends into the inner cavity of the housing 205.

[0060] It should be noted that the housing 205 provides an independent and enclosed space for the first gear 209 and the second gear 210, which can effectively prevent external dust and impurities from entering, avoid gear wear and jamming, ensure the smoothness and accuracy of gear transmission, extend gear service life, and reduce the failure rate of the device. At the same time, the enclosed environment can reduce the leakage of noise generated by gear transmission and reduce noise pollution during device operation. In addition, this layout makes the device structure more compact and reasonable, facilitates overall installation, maintenance and management, and helps to improve the stability and reliability of the device, ensuring the smooth progress of the low-energy coal chemical high-salt wastewater desalination crystallization process.

[0061] In this embodiment of the application, the outlet of the processing box 1 is provided with a cleaning pipe 13, and the cleaning pipe 13 is provided with a valve.

[0062] It should be noted that after the device has been running for a period of time, the impurities and sludge accumulated at the bottom of the treatment tank 1 can be conveniently and quickly discharged by opening the valve and using the cleaning pipe 13.

[0063] In this embodiment, the filter assembly 3 includes a pump body 301, a filter cartridge 304, and an ultrafiltration membrane assembly 305. The pump body 301 is located on the top of the treatment tank 1, and its input end is connected to the filter chamber via a first connecting pipe 302. The filter cartridge 304 is fixed to the outer wall of the treatment tank 1, and its inlet is connected to the output end of the pump body 301 via a second connecting pipe 303. The ultrafiltration membrane assembly 305 is detachably installed inside the filter cartridge 304 and is used for fine filtration of the pre-purified high-salt wastewater. A clean water outlet 11 is provided at the bottom of the side wall of the filter cartridge 304, and a drain pipe 10 is provided in the middle of its side wall for cleaning impurities on the ultrafiltration membrane assembly 305.

[0064] In this embodiment, the pump body 301 of the filter assembly 3 is located at the top of the treatment tank 1 and is connected to the filter chamber and filter cartridge 304 through the first connecting pipe 302. It can efficiently pump the pre-purified high-salt wastewater to the filter cartridge 304. The filter cartridge 304 is fixed to the outer wall of the treatment tank 1, and the ultrafiltration membrane assembly 305 installed inside can perform fine filtration on the high-salt wastewater, effectively removing tiny impurities and pollutants, and improving the purification quality of the high-salt wastewater. The detachable design facilitates the replacement and maintenance of the ultrafiltration membrane assembly 305, reducing maintenance costs. The clean water outlet 11 at the bottom of the side wall of the filter cartridge 304 ensures that the finely filtered clean water is discharged smoothly, while the middle drain pipe 10 can clean the impurities accumulated on the ultrafiltration membrane assembly 305 in a timely manner, preventing blockage and ensuring filtration efficiency and effect, making the entire low-energy coal chemical high-salt wastewater desalination crystallization device operate more stably and efficiently.

[0065] In this embodiment, the low-energy coal chemical high-salt wastewater desalination crystallization device further includes a membrane self-cleaning mechanism. The membrane self-cleaning mechanism includes a third motor 6, a connecting shaft 7, and a cleaning plate 8. The third motor 6 is installed at the bottom of the filter cartridge 304, and its output end extends into the filter cartridge 304 and is connected to the connecting shaft 7. The cleaning plate 8 is fixedly connected to the outer wall of the connecting shaft 7 and contacts the surface of the ultrafiltration membrane module 305.

[0066] It should be noted that the third motor 6 is installed at the bottom of the filter cartridge 304 and its output end is connected to the connecting shaft 7, driving the cleaning plate 8 to rotate. Since the cleaning plate 8 is in contact with the surface of the ultrafiltration membrane module 305, it can continuously scrape the surface of the ultrafiltration membrane during rotation, effectively removing impurities and dirt attached to it, preventing the ultrafiltration membrane from clogging, ensuring the filtration performance and flux of the ultrafiltration membrane module 305, extending its service life, and reducing the cost increase caused by frequent replacement of the ultrafiltration membrane. At the same time, the membrane self-cleaning mechanism does not require frequent manual intervention, reducing the difficulty and workload of maintenance, improving the automation and stability of the device operation, and ensuring the efficient and continuous operation of the low-energy coal chemical high-salt wastewater desalination crystallization process.

[0067] In this embodiment, the ultrafiltration membrane assembly 305 includes a first filter membrane and a second filter membrane. Both the first and second filter membranes are fixedly disposed within a filter cartridge 304 and spaced apart along the height of the filter cartridge 304. The first filter membrane is located above the second filter membrane, and the pore size of the first filter membrane is larger than that of the second filter membrane. Two cleaning plates 8 are provided. The two cleaning plates 8 respectively contact the surfaces of the first and second filter membranes, forming a two-stage filtration structure from coarse to fine.

[0068] In a preferred embodiment of this application, both the first and second filter membranes are made of polyvinylidene fluoride (PVDF). This material possesses excellent chemical stability, corrosion resistance, and good mechanical strength, making it adaptable to the complex compositional environment of high-salt coal chemical wastewater and ensuring stable performance of the filter membranes during long-term use. The pore size of the first filter membrane is 0.008-0.01 micrometers, while the pore size of the second filter membrane is 0.005-0.008 micrometers, meaning the pore size of the first filter membrane is larger than that of the second filter membrane. Working synergistically, they can efficiently intercept small particles, colloids, and some organic matter in the wastewater. The larger-pore-size first filter membrane initially intercepts larger impurities, while the smaller-pore-size second filter membrane further refines the filtration, effectively improving the wastewater purification effect and providing a high-quality water source for subsequent salt separation and crystallization treatment. This contributes to the efficient and stable operation of the low-energy-consumption coal chemical high-salt wastewater salt separation and crystallization device.

[0069] In this embodiment, the stirring unit includes a first motor 202, a stirrer 203, and a mounting plate 201. The mounting plate 201 is fixed to the top of the processing tank 1. The first motor 202 is mounted on the top of the processing tank 1. The stirrer 203 is connected to the output end of the first motor 202 and extends into the sedimentation chamber.

[0070] It should be noted that in the low-energy coal chemical high-salt wastewater desalination crystallization device of this application embodiment, the mounting plate 201 of the stirring unit is fixed to the top of the treatment tank 1 to provide stable support for the overall structure. The first motor 202 is installed on the top of the treatment tank 1 and connected to the stirrer 203 extending to the sedimentation chamber through the output end. This design enables the stirrer 203 to operate efficiently in the sedimentation chamber, fully stir the high-salt wastewater and coagulant, promote the rapid and uniform mixing of the two, greatly improve the flocculation reaction efficiency, allow impurities to fully coagulate into large suspended particles, facilitate subsequent filtration and separation, effectively reduce the difficulty of wastewater treatment, improve the treatment effect and operational stability of the entire desalination crystallization device, and help achieve the goal of low-energy and high-efficiency wastewater treatment.

[0071] This application provides a low-energy coal chemical high-salt wastewater desalination crystallization method, including the aforementioned low-energy coal chemical high-salt wastewater desalination crystallization device, and the method further includes:

[0072] High-salt wastewater is fed into the sedimentation chamber of treatment tank 1, coagulant is added, and forced mixing and flocculation are carried out through the stirring unit.

[0073] Specifically, add 50-200 mg / L of polyaluminum chloride and force mix it with a stirring unit at a speed of 100-150 r / min to ensure that the high-salt wastewater and coagulant are in full contact, promote the flocculation reaction, and cause the impurities in the wastewater to coagulate into large suspended particles.

[0074] After flocculation, the high-salt wastewater passes through a detachable filter plate 204 to intercept large suspended solids, and the preliminarily purified high-salt wastewater enters the filtration chamber. The detachable filter plate 204 effectively intercepts large suspended solids, preventing them from entering subsequent filtration stages, thus improving the efficiency and quality of subsequent filtration.

[0075] The high-salt wastewater that has been initially purified is further filtered by the filter assembly 3 to remove colloids and organic matter.

[0076] Specifically, the pre-purified high-salt wastewater is transported to the ultrafiltration membrane module 305 via the pump body 301. Colloidal and organic matter are intercepted under a pressure of 0.1-0.3MPa. The membrane self-cleaning mechanism is activated every 50 minutes to clean the membrane surface for 2 minutes, ensuring the filtration performance of the ultrafiltration membrane module 305, preventing clogging, and ensuring fine filtration effect.

[0077] After fine filtration, the high-salt wastewater enters the evaporator crystallizer 5 through a pipeline, where sodium chloride and sodium sulfate are separated and crystallized for recovery.

[0078] Specifically, the finely filtered water enters the evaporator crystallizer 5, where sodium chloride and sodium sulfate crystals are separated and recovered through multi-effect evaporation technology, with a purity of ≥98.5%. This achieves the resource utilization of high-salt wastewater, reduces environmental pollution, and lowers the company's operating costs.

[0079] It should be noted that the low-energy coal chemical high-salt wastewater desalination crystallization method provided in this application promotes flocculation by reasonably adding coagulants and using a stirring unit for forced mixing, causing impurities to agglomerate into large suspended particles. These particles are then initially intercepted by a detachable filter plate 204, effectively removing large particulate impurities. Subsequently, the filter assembly 3 performs fine filtration under specific pressure to retain colloids and organic matter. In conjunction with a membrane self-cleaning mechanism, the surface of the ultrafiltration membrane assembly 305 is cleaned regularly to ensure filtration performance. Finally, high-purity sodium chloride and sodium sulfate crystals are recovered through multi-effect evaporation technology. This method achieves efficient treatment and resource utilization of high-salt wastewater, reduces subsequent evaporation and crystallization energy consumption, reduces enterprise operating costs, and mitigates environmental pollution.

[0080] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0081] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A low-energy coal chemical high-salt wastewater desalination crystallization device, characterized in that, include: Treatment tank (1) is used to receive and pretreat high-salt wastewater; The pretreatment mechanism (2), located inside the treatment tank (1), includes: a stirring unit, fixed to the top of the treatment tank (1) and extending into its inner cavity, used to fully mix the high-salt wastewater with the coagulant to promote the flocculation reaction; and a detachable filter plate (204), vertically arranged in the inner cavity of the treatment tank (1), dividing the inner cavity of the treatment tank (1) into a sedimentation chamber and a filtration chamber, used to intercept large particulate suspended matter generated by the flocculation reaction, so that the high-salt wastewater entering the filtration chamber is initially purified. The filter assembly (3) is installed on the side wall of the treatment box (1), and its water inlet end is connected to the filter chamber. It is used to finely filter the high-salt wastewater in the filter chamber. A clean water outlet (11) is provided at the bottom of the side wall of the filter assembly (3). The evaporator crystallizer (5) is connected to the clean water outlet (11) of the filter assembly (3) through a conveying pipeline and is used to perform salt separation crystallization on the finely filtered high-salt wastewater.

2. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 1, characterized in that, The pretreatment mechanism (2) also includes a scraping component; The scraping assembly includes a second motor (206), a rotating rod (207), a first gear (209), a second gear (210), a threaded rod (211), a spiral discharge shaft (208), and a scraper (212); The second motor (206) is mounted on the side wall of the processing box (1); One end of the rotating rod (207) is connected to the output end of the second motor (206), and the other end extends to the sedimentation chamber of the processing box (1); One end of the spiral discharge shaft (208) is connected to the end of the rotating rod (207) away from the second motor (206), and the other end is connected to the outlet of the processing box (1) for discharging the sediment at the bottom of the sedimentation chamber; The first gear (209) is fixedly connected to the outer wall of the rotating rod (207) and located outside the processing box (1), and the second gear (210) meshes with the first gear (209); The threaded rod (211) is fixedly connected to the second gear (210) and extends to the sedimentation chamber; The scraper (212) is threadedly connected to the threaded rod (211) via a threaded sleeve and is used to clean the surface of the removable filter plate (204).

3. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 2, characterized in that, The top of the detachable filter plate (204) is provided with a sliding groove, and the top of the scraper (212) is provided with a slider (12) that slides in cooperation with the sliding groove.

4. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 2, characterized in that, It also includes the housing (205); Both the first gear (209) and the second gear (210) are disposed within the housing (205); The second motor (206) is mounted on the outer wall of the housing (205), and its output end extends into the inner cavity of the housing (205).

5. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 1, characterized in that, The outlet of the processing box (1) is provided with a cleaning pipe (13), and the cleaning pipe (13) is provided with a valve.

6. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 1, characterized in that, The filtration assembly (3) includes a pump body (301), a filter cartridge (304), and an ultrafiltration membrane assembly (305); The pump body (301) is located on the top of the processing box (1), and its input end is connected to the filter chamber through the first connecting pipe (302); The filter cartridge (304) is fixed to the outer wall of the treatment box (1), and its inlet is connected to the output end of the pump body (301) through the second connecting pipe (303); The ultrafiltration membrane module (305) is detachably installed inside the filter cartridge (304) for fine filtration of the pre-purified high-salt wastewater; The bottom of the side wall of the filter cartridge (304) is provided with a clean water outlet (11), and a drain pipe (10) is provided in the middle of its side wall for cleaning impurities on the ultrafiltration membrane module (305).

7. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 6, characterized in that, It also includes a membrane self-cleaning mechanism; The membrane self-cleaning mechanism includes a third motor (6), a connecting shaft (7), and a cleaning plate (8); The third motor (6) is installed at the bottom of the filter cylinder (304), and its output end extends into the filter cylinder (304) and is connected to the connecting shaft (7); The cleaning plate (8) is fixedly connected to the outer wall of the connecting shaft (7) and in contact with the surface of the ultrafiltration membrane assembly (305).

8. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 7, characterized in that, The ultrafiltration membrane assembly (305) includes a first filtration membrane and a second filtration membrane; The first filter membrane and the second filter membrane are both fixedly disposed inside the filter cylinder (304) and are spaced apart along the height direction of the filter cylinder (304); The first filter membrane is located above the second filter membrane, and the pore size of the first filter membrane is larger than the pore size of the second filter membrane. Two cleaning plates (8) are provided; The two cleaning plates (8) are in contact with the surfaces of the first filter membrane and the second filter membrane, respectively.

9. The low-energy coal chemical high-salt wastewater desalination crystallization device according to claim 1, characterized in that, The stirring unit includes a first motor (202), a stirrer (203), and a mounting plate (201); The mounting plate (201) is fixed to the top of the processing box (1); The first motor (202) is mounted on the top of the processing box (1); The stirrer (203) is connected to the output end of the first motor (202) and extends to the sedimentation chamber.

10. A low-energy coal chemical high-salt wastewater desalination crystallization method, characterized in that, The method includes the low-energy coal chemical high-salt wastewater desalination crystallization device according to any one of claims 1-9, and further includes: High-salt wastewater is fed into the sedimentation chamber of the treatment tank (1), coagulant is added, and forced mixing and flocculation are carried out through the stirring unit; After flocculation, the high-salt wastewater passes through a detachable filter plate (204) to intercept large suspended particles, and the preliminarily purified high-salt wastewater enters the filtration chamber. The high-salt wastewater that has been initially purified is finely filtered through the filter assembly (3) to retain colloids and organic matter; After fine filtration, the high-salt wastewater enters the evaporator crystallizer (5) through the conveying pipeline, where sodium chloride and sodium sulfate are separated and crystallized for recovery.

Images