Zero-discharge integrated device for flash evaporation of high-salinity wastewater by using waste heat

Abstract

The utility model relates to the technical field of zero discharge of wastewater, and provides a zero-discharge integrated device for flash evaporation of high-salinity wastewater by waste heat, which comprises an evaporation kettle, the evaporation kettle comprises a middle-layer tank body, an upper-layer tank body is arranged at the upper end of the middle-layer tank body, a lower-layer tank body is fixedly mounted at the lower end of the middle-layer tank body, and a connecting pipe I is mounted at the upper end of the upper-layer tank body in a penetrating manner; a heating coil is fixedly mounted on the outer side of the lower end of the middle-layer tank body; a supporting frame is fixedly mounted on the outer side of the lower-layer tank body; a tower kettle ring is slidably mounted in the middle-layer tank body; a cleaning assembly is fixedly mounted at the lower end of the tower kettle ring and drives a screw rod through a driving motor; the connecting ring, the connecting rod and the cleaning scraping disc operate, so that residual salt crystals on the inner wall of the middle-layer tank body can be cleaned in time, good heat transfer and fluid flowing properties of equipment are maintained, the evaporation efficiency is guaranteed, and the energy consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of zero wastewater discharge technology, and in particular to an integrated device for zero discharge of high-salt wastewater by flash evaporation using waste heat. Background Technology

[0002] my country is a country with scarce water resources, but it is also a major industrial country. The amount of industrial wastewater generated and the pollution load are very large. Industrial wastewater contains a large amount of pollutants such as organic matter, inorganic salts, heavy metals, and recalcitrant substances. If it is not treated or not treated properly, it will cause problems such as eutrophication of water bodies, increased toxicity, and ecological damage. In recent years, my country's wastewater discharge standards have become increasingly stringent. In particular, the "Ten Measures for Water Pollution Prevention and Control" issued by the State Council in 2015 has elevated water environmental protection to the national strategic level, and achieving "zero discharge" of wastewater is of great significance.

[0003] Zero wastewater discharge (ZFD) is an environmental protection technology that aims to recycle industrial water to achieve "zero discharge" of wastewater. It involves reusing industrial water, recovering and reusing wastewater with high salinity and pollutant content, or using a filter press to separate water-insoluble substances for recycling. Throughout the process, no waste liquid is discharged from the factory. The salts and pollutants in the wastewater are concentrated, crystallized, or filtered into solid waste residue, which is then sent to a landfill or recycled as chemical raw materials.

[0004] Regarding the aforementioned technologies, salt and impurities in wastewater are prone to crystallize and precipitate during the evaporation process, adhering to the inner walls of equipment such as evaporation kettles and heat exchanger pipes, forming scale. Scale can affect the heat transfer efficiency and fluid flow of the equipment, leading to decreased evaporation efficiency, increased energy consumption, and even equipment failure. Regular shutdowns for cleaning and maintenance are required, affecting the continuous operation and production efficiency of the equipment. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the defects of the existing technology. This utility model proposes an integrated device for zero discharge of high-salt wastewater by flash evaporation of waste heat, in order to solve the problem that salt and impurities in wastewater are easy to crystallize and precipitate during the evaporation process and adhere to the inner wall of the equipment, resulting in a decrease in evaporation efficiency and an increase in energy consumption.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: an integrated device for zero-discharge flash evaporation of high-salt wastewater using waste heat, including an evaporation kettle, with a connecting pipe 1 penetrating through the upper end of the evaporation kettle, and a connecting pipe 2 penetrating through the interior of the evaporation kettle. When recycling and reusing high-salt wastewater, the connecting pipe 1 is connected to a primary heat exchanger, the primary heat exchanger is connected to a secondary heat exchanger, and the secondary heat exchanger is fixedly connected to the connecting pipe 2. The high-salt wastewater is first pressurized by a high-pressure pump to 2MPa-4MPa, and then passes through the primary heat exchanger to exchange heat with the steam coming out of the connecting pipe 1. The wastewater is heated, the steam is condensed, and the wastewater then enters the secondary heat exchanger. The heat from the secondary heat exchanger is obtained by using the waste heat from the introduced high-temperature waste gas to reheat the wastewater to above 100°C, and then it enters the evaporation kettle for evaporation and crystallization.

[0007] Preferably, the evaporator includes a middle tank, an upper tank is provided at the upper end of the middle tank, a lower tank is fixedly installed at the lower end of the middle tank, a connecting pipe 1 is installed through the upper end of the upper tank, a connecting pipe 2 is installed through the interior of the middle tank, a heating coil is fixedly installed on the outer side of the lower end of the middle tank, and a support frame is fixedly installed on the outer side of the lower tank.

[0008] Preferably, the second connecting pipe is connected to the secondary heat exchanger. A reflux nozzle is fixedly installed at the output end of the second connecting pipe, and a reflux regulating valve is fixedly installed on the outside of the output end of the second connecting pipe. The interior of the evaporator is heated by the heating coil. At the same time, the high-salt wastewater heated by the secondary heat exchanger is sprayed into the evaporator through the reflux nozzle and evaporates instantly. The salt in the water crystallizes. As the water evaporates, the salt crystal powder falls into the lower part of the evaporator. The spray water volume can be controlled by adjusting the reflux regulating valve.

[0009] Preferably, a tower bottom ring is slidably installed inside the middle tank. The tower bottom ring is located at the lower end of the reflux nozzle. A cleaning component is fixedly installed at the lower end of the tower bottom ring. The cleaning component is slidably connected to the middle tank. High-salt wastewater entering the evaporator through the reflux nozzle is sprayed onto the tower bottom ring to prevent wastewater from directly spraying onto the evaporator wall, causing scaling and corrosion.

[0010] Preferably, the cleaning component includes a connecting shell, which is fixedly connected to the outer wall of the intermediate tank. A drive motor is fixedly installed inside the connecting shell, and a lead screw is fixedly installed at the drive end of the drive motor. The upper end of the lead screw is rotatably connected to the connecting shell. A connecting ring is threaded onto the outer side of the lead screw, and a connecting rod is fixedly installed on the outer side of the connecting ring. The connecting rod is located inside the intermediate tank and is slidably connected to it. A cleaning scraper is fixedly installed on the side of the connecting rod away from the connecting ring. The cleaning scraper is located at the lower end of the tower bottom ring and is slidably connected to it. The drive motor drives the lead screw to rotate, causing the connecting ring and the connecting rod to slide inside the intermediate tank. This causes the cleaning scraper to scrape along the inner wall of the intermediate tank, cleaning away any residual salt crystals on the inner wall of the intermediate tank, preventing scale formation, which would affect the heat transfer efficiency and fluid flow of the equipment, leading to decreased evaporation efficiency and increased energy consumption.

[0011] Preferably, a groove is provided at the connection between the middle tank and the connecting rod. The groove is cross-shaped, and the length of the connecting rod is less than the length of the groove. By sliding the connecting rod inside the groove, the cleaning scraper can scrape up and down along the inner wall of the middle tank to clean the small amount of salt crystals remaining on the inner wall of the middle tank.

[0012] Preferably, the outer side of the cleaning scraper is provided with an upper scraper and a lower scraper. Both the upper and lower scrapers are provided with multiple sets of discharge troughs. When the cleaning scraper moves upward, the upper scraper cleans the salt crystals remaining on the inner wall of the middle tank and the crystals fall into the lower tank through the discharge trough for collection.

[0013] Preferably, an ash hopper is installed through the lower end of the lower tank, and an ash discharge valve is provided at the outlet of the ash hopper. A protective shell is fixedly installed on the outer side of the lower end of the lower tank, and a servo motor is fixedly installed inside the protective shell. The drive end of the servo motor passes through the lower tank and is fixedly installed with a scraper. The scraper is rotatably connected to the inner wall of the lower tank. The crystallized salt falling into the lower tank is continuously driven by the servo motor to rotate the scraper in both directions, scraping the crystallized salt into the ash hopper for collection, and then collecting it by opening the ash discharge valve.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention proposes an integrated device for zero-discharge flash evaporation of high-salt wastewater using waste heat. The upper tank's connecting pipe connects to the primary heat exchanger, enabling preliminary heat exchange between steam and wastewater, effectively recovering heat. The middle tank's internal connecting pipe and reflux nozzle, along with heating coils, ensure flash crystallization of the high-salt wastewater under suitable conditions. The ingenious combination of the tower ring and cleaning components significantly reduces the risk of scaling and corrosion caused by direct wastewater spraying onto the tower wall. The cleaning components, driven by a motor, operate the connecting ring, connecting rod, and cleaning scraper, promptly cleaning residual salt crystals from the inner wall of the middle tank, maintaining good heat transfer and fluid flow performance, ensuring evaporation efficiency, and reducing energy consumption. The lower tank is equipped with an ash hopper, ash discharge valve, and a scraper driven by a servo motor, facilitating the collection and discharge of crystallized salt. Attached Figure Description

[0016] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein: Figure 1 The schematic diagram illustrates the overall structure according to one embodiment of the present invention. Figure 1 ; Figure 2 The schematic diagram illustrates the overall structure according to one embodiment of the present invention. Figure 2 ; Figure 3 The schematic diagram shows the internal structure of an evaporator according to one embodiment of the present invention; Figure 4 The schematic diagram shows a structural diagram of a cleaning component according to one embodiment of the present invention; Figure 5 The schematic diagram shows a cleaning scraper structure according to one embodiment of the present invention; Figure 6 The schematic diagram shows the internal structure of the middle tank according to one embodiment of the present invention; Figure 7 The diagram schematically shows a lower tank structure according to one embodiment of the present invention.

[0017] The diagram is labeled as follows: 1. Evaporator; 11. Middle tank; 111. Connecting pipe 2; 112. Reflux regulating valve; 113. Reflux nozzle; 114. Slide chute; 12. Upper tank; 13. Connecting pipe 1; 14. Heating coil; 15. Support frame; 16. Cleaning assembly; 161. Connecting shell; 162. Drive motor; 163. Lead screw; 164. Connecting ring; 165. Connecting rod; 166. Cleaning scraper; 1661. Upper scraper; 1662. Lower scraper; 1663. Discharge chute; 164. Connecting ring; 165. Connecting rod; 17. Lower tank; 171. Ash hopper; 172. Ash discharge valve; 173. Scraper; 174. Protective shell; 175. Servo motor; 18. Tower ring. Detailed Implementation

[0018] It is readily understood that, based on the technical solution of this utility model, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this utility model. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model and should not be considered as the entirety of this utility model or as limitations or restrictions on the technical solution of this utility model.

[0019] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings.

[0020] According to one embodiment of the present invention, in conjunction with Figure 1-3 The diagram illustrates an integrated device for zero-discharge flash evaporation of high-salt wastewater using waste heat. The device includes an evaporator 1, with a connecting pipe 13 extending through its upper end and a connecting pipe 111 extending through its interior. For recycling and reusing high-salt wastewater, the connecting pipe 13 is connected to a primary heat exchanger, which in turn is connected to a secondary heat exchanger. The secondary heat exchanger is then fixedly connected to the connecting pipe 111. The high-salt wastewater is first pressurized by a high-pressure pump to 2-4 MPa. It then exchanges heat with the steam exiting the connecting pipe 13 through the primary heat exchanger, heating the wastewater and condensing the steam. The wastewater then enters the secondary heat exchanger, where the heat from the imported high-temperature waste gas is used to reheat the wastewater to over 100°C before it enters the evaporator 1 for evaporation and crystallization.

[0021] Combination Figure 1-3 As shown, the evaporator 1 includes a middle tank 11, an upper tank 12 is provided at the upper end of the middle tank 11, a lower tank 17 is fixedly installed at the lower end of the middle tank 11, a connecting pipe 13 is installed through the upper end of the upper tank 12, a connecting pipe 111 is installed through the inside of the middle tank 11, a heating coil 14 is fixedly installed on the outer side of the lower end of the middle tank 11, and a support frame 15 is fixedly installed on the outer side of the lower tank 17.

[0022] Combination Figure 3 As shown, connecting pipe 2 111 is connected to the secondary heat exchanger. A reflux nozzle 113 is fixedly installed at the output end of connecting pipe 2 111, and a reflux regulating valve 112 is fixedly installed on the outside of the output end of connecting pipe 2 111. The interior of the evaporator 1 is heated by the heating coil 14. At the same time, the high-salt wastewater heated by the secondary heat exchanger is sprayed into the evaporator 1 through the reflux nozzle 113 and evaporates instantly. The salt in the water crystallizes. As the water evaporates, the salt crystal powder falls into the lower part of the evaporator 1. The spray water volume can be controlled by adjusting the reflux regulating valve 112.

[0023] Combination Figure 3 As shown, a tower bottom ring 18 is slidably installed inside the middle tank 11. The tower bottom ring 18 is located at the lower end of the reflux nozzle 113. A cleaning component 16 is fixedly installed at the lower end of the tower bottom ring 18. The cleaning component 16 is slidably connected to the middle tank 11. High-salt wastewater entering the evaporator 1 through the reflux nozzle 113 is sprayed onto the tower bottom ring 18 to prevent wastewater from directly spraying onto the wall of the evaporator 1, causing scaling and corrosion.

[0024] Combination Figure 3-4 As shown, the cleaning assembly 16 includes a connecting shell 161, which is fixedly connected to the outer wall of the middle tank 11. A drive motor 162 is fixedly installed inside the connecting shell 161. A lead screw 163 is fixedly installed at the drive end of the drive motor 162. The upper end of the lead screw 163 is rotatably connected to the connecting shell 161. A connecting ring 164 is threaded onto the outer side of the lead screw 163. A connecting rod 165 is fixedly installed on the outer side of the connecting ring 164. The connecting rod 165 is located inside the middle tank 11 and slidably connected to it. The connecting rod 165 is located away from the connecting shell 161. A cleaning scraper 166 is fixedly installed on one side of the ring 164. The cleaning scraper 166 is located at the lower end of the tower bottom ring 18 and is slidably connected to it. The drive motor 162 drives the lead screw 163 to rotate, which drives the connecting ring 164 and the connecting rod 165 to slide inside the middle tank 11. This causes the cleaning scraper 166 to scrape along the inner wall of the middle tank 11, cleaning a small amount of residual salt crystals on the inner wall of the middle tank 11, preventing scale formation on the inner wall, which would affect the heat transfer efficiency and fluid flow of the equipment, leading to a decrease in evaporation efficiency and an increase in energy consumption.

[0025] Combination Figure 3-4 , Figure 6 As shown, a groove 114 is provided at the connection between the middle tank 11 and the connecting rod 165. The groove 114 is in the shape of a cross. The length of the connecting rod 165 is less than the length of the groove 114. By sliding the connecting rod 165 inside the groove 114, the cleaning scraper 166 can scrape up and down along the inner wall of the middle tank 11 to clean the small amount of salt crystals remaining on the inner wall of the middle tank 11.

[0026] Combination Figure 4-5 As shown, the outer side of the cleaning scraper 166 is provided with an upper scraper 1661 and a lower scraper 1662. Both the upper scraper 1661 and the lower scraper 1662 are provided with multiple sets of discharge troughs 1663. When the cleaning scraper 166 moves upward, the upper scraper 1661 cleans the salt crystals remaining on the inner wall of the middle tank 11, and the crystals fall into the lower tank 17 through the discharge troughs 1663 for collection.

[0027] Combination Figure 3 , Figure 7As shown, a hopper 171 is installed through the lower end of the lower tank 17. A discharge valve 172 is provided at the outlet of the hopper 171. A protective shell 174 is fixedly installed on the outer side of the lower end of the lower tank 17. A servo motor 175 is fixedly installed inside the protective shell 174. The drive end of the servo motor 175 passes through the lower tank 17 and a scraper 173 is fixedly installed thereon. The scraper 173 is rotatably connected to the inner wall of the lower tank 17. The crystallized salt falling into the lower tank 17 is continuously driven by the servo motor 175 to rotate the scraper 173 in both directions, scraping the crystallized salt into the hopper 171 for collection. The collection is also achieved by opening the discharge valve 172.

[0028] In this embodiment, the high-salt wastewater is first pressurized to 2MPa-4MPa by a high-pressure pump, and then heated by exchanging heat with steam from connecting pipe 13 in a primary heat exchanger. The steam condenses, and the wastewater then enters a secondary heat exchanger, where it is reheated to over 100°C using the residual heat of the introduced high-temperature waste gas. Next, it is injected into the evaporator 1 through connecting pipe 211 and reflux nozzle 113. Under the auxiliary heating of heating coil 14 and the vacuum environment of the evaporator 1, the wastewater evaporates instantly, and the salt crystallizes. The spray water volume can be controlled by adjusting the reflux regulating valve 112. The sprayed wastewater is first sprayed onto the tower bottom ring 18 to prevent direct spraying onto the bottom wall, which would cause scaling and corrosion. The drive motor 162 drives the lead screw 163 to rotate, causing the connecting ring 164 and connecting rod 165 to drive the cleaning scraper 166 to scrape the residual salt crystals along the inner wall of the middle tank 11. After the crystallized salt falls into the lower tank 17, the servo motor 175 drives the scraper 173 to rotate in both directions to scrape the crystallized salt into the ash hopper 171, and finally discharge it through the ash discharge valve 172.

[0029] The technical scope of this utility model is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this utility model, and all such modifications and variations should fall within the protection scope of this utility model.

Claims

1. An integrated device for zero-discharge flash evaporation of high-salt wastewater using waste heat, characterized in that: The apparatus includes an evaporating kettle, which comprises a middle tank, an upper tank at the upper end of the middle tank, and a lower tank fixedly installed at the lower end of the middle tank. A connecting pipe is installed through the upper end of the upper tank, and a connecting pipe is installed through the interior of the middle tank. A heating coil is fixedly installed on the outer side of the lower end of the middle tank, and a support frame is fixedly installed on the outer side of the lower tank. A tower receptacle ring is slidably installed inside the middle tank, and a cleaning component is fixedly installed at the lower end of the tower receptacle ring. The cleaning component is slidably connected to the middle tank.

2. The integrated device for zero-discharge of high-salinity wastewater using waste heat flash evaporation as described in claim 1, characterized in that: The second connecting pipe is connected to the secondary heat exchanger. A reflux nozzle is fixedly installed at the output end of the second connecting pipe. The bottom ring of the tower is located at the lower end of the reflux nozzle. A reflux regulating valve is fixedly installed on the outside of the second connecting pipe.

3. The integrated device for zero-discharge of high-salinity wastewater using waste heat flash evaporation as described in claim 1, characterized in that: The cleaning assembly includes a connecting shell, which is fixedly connected to the outer wall of the intermediate tank. A drive motor is fixedly installed inside the connecting shell, and a lead screw is fixedly installed at the drive end of the drive motor. The upper end of the lead screw is rotatably connected to the connecting shell. A connecting ring is threaded onto the outer side of the lead screw, and a connecting rod is fixedly installed on the outer side of the connecting ring. The connecting rod is located inside the intermediate tank, and a cleaning scraper is fixedly installed on the side of the connecting rod away from the connecting ring. The cleaning scraper is located at the lower end of the tower bottom ring.

4. The integrated device for zero-discharge of high-salinity wastewater using waste heat flash evaporation as described in claim 3, characterized in that: A groove is provided at the connection between the middle tank and the connecting rod, and the length of the connecting rod is less than the length of the groove.

5. The integrated device for zero-discharge of high-salinity wastewater using waste heat flash evaporation according to claim 3, characterized in that: The outer side of the cleaning scraper is provided with an upper scraper and a lower scraper, and multiple sets of discharge grooves are provided on both the upper scraper and the lower scraper.

6. The integrated device for zero-discharge of high-salinity wastewater using waste heat flash evaporation according to claim 1, characterized in that: A hopper is installed through the lower end of the lower tank. A discharge valve is provided at the outlet of the hopper. A protective shell is fixedly installed on the outer side of the lower end of the lower tank. A servo motor is fixedly installed inside the protective shell. The drive end of the servo motor passes through the lower tank and is fixedly installed with a scraper. The scraper is rotatably connected to the inner wall of the lower tank.

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