Evaporative crystallization device based on high-concentration wastewater and zero discharge process

Abstract

The invention discloses an evaporative crystallization device based on high-concentration wastewater and a zero discharge process, and relates to the technical field of wastewater treatment.The evaporative crystallization device based on the high-concentration wastewater comprises an evaporation tank, and a drainage device is arranged in the evaporation tank; the flow guide device comprises a heat conduction inner barrel fixed in the evaporation tank, an inner ring channel formed in the center of the heat conduction inner barrel, a flow guide pipe fixed in the inner ring channel and a plurality of groups of outer ring channels formed in the heat conduction inner barrel, and the plurality of groups of outer ring channels are sequentially formed from inside to outside by taking the inner ring channel as the center; first water outlets which are arranged up and down are formed between the inner ring channel and the adjacent outer ring channel, and second water outlets are formed between the other outer ring channels. By arranging the drainage device, when entering the evaporation tank, wastewater can sequentially pass through the multiple groups of outer ring channels along the inner ring channel in an S-shaped trend so as to diffuse and flow towards the periphery, so that disorder and stagnation of flow in a traditional system are avoided, and continuous flowability of the wastewater is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to an evaporation crystallization device based on high-concentration wastewater and a zero-discharge process. Background Art

[0002] High-concentration wastewater usually contains high concentrations of pollutants and a large amount of salt. Direct discharge of high-concentration wastewater will have extremely serious negative impacts on the environment. Therefore, the treatment of high-concentration wastewater is particularly important. Among them, evaporation crystallization is a widely used and effective wastewater treatment method. Its core principle is to use evaporation of water to continuously increase the solute concentration in the wastewater until it reaches saturation and further crystallizes and precipitates, and finally converts it into a solid crystalline form, thereby realizing the recycling and reuse of water resources.

[0003] The existing publication number CN110395838A discloses a high-salt wastewater evaporation crystallization zero-emission equipment, which includes a preliminary treatment component, a preheating component, an evaporation component, a thermal insulation component, a flash evaporation component and a separation component. The preliminary treatment component includes a preliminary treatment tank and a first stirring component. The top of the preliminary treatment tank is provided with a liquid inlet and a drug inlet. The first stirring component is arranged inside the preliminary treatment tank. The preheating component includes a heat exchanger. The evaporation component includes an evaporation tank, a second stirring component, a vacuum compression component and a heating component. The thermal insulation component includes a thermal insulation tank and a third stirring component. A synchronous drive component is provided between the second stirring component and the third stirring component. The flash evaporation component includes a flash evaporation tank and a steam recovery component. The separation component includes a separation tank and a separation component. Although the above technical scheme can treat high-salt wastewater by evaporation, concentration and crystallization, it can ultimately achieve the advantage of zero emission.

[0004] However, in the prior art, the evaporation crystallization tank mainly relies on the physical evaporation principle to operate. Specifically, the evaporation crystallization tank is heated by an external heating device to increase the temperature of the wastewater in the tank. The water in the wastewater is gradually converted into water vapor and escapes due to the heat, while the solutes such as salts in the wastewater are retained in the tank because they cannot volatilize, thereby achieving the separation of salt substances and water. However, when the evaporation crystallization tank is used to treat wastewater, the wastewater is usually directly injected into the evaporation crystallization tank for heating. Due to the characteristics of the wastewater itself and the influence of the environment in the tank, when the wastewater enters the tank for heating, as the water gradually evaporates, its concentration rises rapidly, which will cause the solute to evaporate. The viscosity of the liquid increases, making the fluidity of the wastewater in the tank worse, and some salt substances are prone to form crystal particles under high temperature and high concentration conditions. These crystal particles will aggregate and adhere to each other, further hindering the flow of the wastewater in the tank, causing the flow of the wastewater in the tank to be disordered and easy to stagnate. At the same time, since the wastewater cannot circulate fully in the tank, the heat transfer efficiency in the tank will be reduced, making the temperature in some local areas too high, while other areas may lack heat, extending the processing time and increasing energy consumption. Therefore, a new type of evaporation crystallization device based on high-concentration wastewater and a zero-emission process are needed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an evaporation crystallization device and a zero-emission process based on high-concentration wastewater, so as to solve the problem that the existing evaporation crystallization tank proposed in the above background technology has poor fluidity of the wastewater in the tank when treating high-concentration wastewater, resulting in low treatment heat transfer efficiency.

[0006] The present invention provides an evaporation crystallization device and a zero-discharge process based on high-concentration wastewater, which adopts the following technical solutions:

[0007] An evaporation crystallization device based on high-concentration wastewater comprises an equipment body, the equipment body comprises an evaporation tank, a sealing cover arranged at the top of the evaporation tank, a heating component arranged in an inner wall interlayer of the evaporation tank, a steam inlet, a steam outlet and a water inlet arranged on the evaporation tank, and a partition arranged at the top of the inner wall of the evaporation tank, and a controller is also arranged outside the evaporation tank;

[0008] The evaporation tank is provided with a drainage device;

[0009] The drainage device comprises a heat-conducting inner barrel fixed in the evaporator, an inner ring channel opened in the center of the heat-conducting inner barrel, a guide pipe fixed in the inner ring channel, and a plurality of outer ring channels opened on the heat-conducting inner barrel, the plurality of outer ring channels being opened sequentially from the inside to the outside with the inner ring channel as the center, a first water outlet arranged vertically is opened between the inner ring channel and the adjacent outer ring channel, a second water outlet is opened between the remaining outer ring channels, and two adjacent groups of second water outlets are arranged high and low, a regulating mechanism for regulating the water inlet is provided at the top of the guide pipe, a water outlet end of the water inlet is connected through the bottom end of the guide pipe, wastewater enters the guide pipe through the water inlet, flows into the inner ring channel, and then flows to the periphery through the plurality of outer ring channels in sequence along the inner ring channel;

[0010] Each group of outer ring channels is provided with a stirring and brushing mechanism;

[0011] The stirring and brushing mechanism comprises two groups of spiral rods arranged in each group of outer ring channels, and the spiral rods are in sliding contact with the inner side walls of the outer ring channels respectively.

[0012] Furthermore, the adjustment mechanism includes a discharge tube fixed at the top of the guide tube, an adjustment plate arranged in the discharge tube and rotating through the central axis, a swing arm fixed at one end of the central axis, a frame fixed on the outer wall of the discharge tube, and a connecting rod movably penetrating the frame, and the connecting rod is rotatably connected to the swing arm through a rotating shaft;

[0013] An electric push rod is installed on the partition, and the output end of the electric push rod is fixedly connected to the connecting rod, wherein a water level sensor is provided above the inner wall of the outermost outer ring channel, and the electric push rod and the water level sensor are electrically connected to the controller. When the water level line inside the outermost outer ring channel is higher than the water level sensor, the water level sensor transmits a signal to the controller. After receiving the signal, the controller controls the electric push rod to start, so that the adjustment plate rotates to adjust the water inlet of the discharge tube.

[0014] Furthermore, the agitating brush mechanism also includes a connecting plate fixed between the multiple groups of spiral rods, a connecting column fixed on the connecting plate, a fixing plate fixed on the connecting column, a main shaft fixed on the fixing plate, a driven gear fixed on the main shaft, and a driving gear meshing with the driven gear;

[0015] A motor is installed on the sealing cover through a bracket, the output end shaft of the motor is fixedly connected to the driving gear, and the motor is electrically connected to the controller. After the motor is started, the main shaft is controlled to rotate, so that the multiple groups of spiral rods rotate along the inner wall of the outer ring channel with the main shaft as the center.

[0016] Furthermore, a cleaning mechanism is provided at the bottom end of the inner wall of each group of the outer ring channels, and the cleaning mechanism includes a pushing block fixed between the bottom ends of the two groups of spiral rods, a slot provided on the pushing block, an extrusion plate provided in the slot that is rotated by a rotating shaft, a convex rod fixed on the rotating shaft, and a torsion spring provided on the rotating shaft;

[0017] The bottom end of each group of the outer ring channels is connected with a slag discharge port, and the bottom ends of multiple groups of the slag discharge ports are connected with an inclined slag discharge pipe. An abutment rod corresponding to the convex rod is fixed on the side wall of each group of the outer ring channels, and the abutment rod is set on the rotation path of the pushing block and close to the slag discharge port.

[0018] Furthermore, the ends of the abutting rod and the protruding rod that are close to each other are both arc-shaped.

[0019] Furthermore, the pushing block is provided with a guide groove for the convex rod to rotate.

[0020] Furthermore, the torsion spring is arranged at the upper and lower ends of the rotating shaft, and the extrusion plate is provided with a notch for the torsion spring to twist.

[0021] Furthermore, a sliding block is fixed on the fixed plate, and an annular sliding groove for the sliding block to slide is provided on the partition plate.

[0022] Furthermore, two sets of limiting plates are fixed to the inner wall of the discharge tube and are arranged opposite to each other. The two sets of limiting plates are arranged up and down, and the two sets of limiting plates are respectively located at the upper and lower positions of the side wall of the adjustment plate.

[0023] A zero-discharge process based on high-concentration wastewater, using the evaporation crystallization device, comprises the following steps:

[0024] S1: Pretreatment step, the high-concentration wastewater first enters the regulating tank, the pH of the wastewater is adjusted to a predetermined range in the regulating tank, an appropriate amount of flocculant is added for flocculation and precipitation, and suspended impurities and some macromolecular organic matter in the wastewater are removed. The supernatant after precipitation is transported to the water inlet of the evaporation crystallization device through a lift pump;

[0025] S2: Evaporation and crystallization step, the pretreated wastewater enters the guide pipe in the heat-conducting inner barrel of the evaporation and crystallization device through the water inlet, and then flows to the periphery through multiple groups of outer ring channels along the inner ring channel opened in the center. Under the heating action of the heating component, the wastewater enters the outer ring channel along the inner ring channel and flows outward in sequence. The water gradually evaporates and the solute concentration continues to increase. During the flow process, the stirring and brushing mechanism continues to operate to keep the wastewater in good fluidity, promote uniform evaporation and crystallization, and the water vapor generated by evaporation rises and enters the gas-liquid separation device through the steam outlet;

[0026] S3: Gas-liquid separation and condensation recovery step. After the water vapor enters the gas-liquid separation device, it is subjected to cyclone separation and wire mesh defoaming treatment to remove the entrained tiny droplets. The separated pure water vapor enters the condensation recovery unit. Through the heat exchange effect of the cooling water pipeline in the condenser, the water vapor is condensed into liquid water and recovered to the clean water storage tank for industrial reuse or standard discharge.

[0027] S4: Solid discharging step. After the solid material crystallized in the main body of the evaporation crystallization tank reaches a certain amount, the discharge valve of the slag discharge port is opened, and the solid crystals are scraped off by rotating the spiral rod, and the extrusion plate is squeezed and pushed by the push block to make the scraped solid crystals be transported outward through the slag discharge port and the slag discharge pipe, and then the subsequent drying and packaging processes, or purification and other deep treatments are carried out to achieve the goal of zero discharge of high-concentration wastewater.

[0028] Beneficial effects of the present invention:

[0029] 1. By providing a drainage device, when the wastewater enters the evaporation tank, it can pass through multiple groups of outer ring channels in sequence along the inner ring channel, and flow in an S-shaped direction to diffuse and flow to the periphery. By providing a multi-channel structure, the wastewater can flow along a specific trajectory, avoiding the disorder and stagnation of the flow in the traditional system, and ensuring the continuous fluidity of the wastewater. The multi-channel structure can also impose constraints and driving effects on the mixture of wastewater and precipitated crystals to prevent channel blockage, thereby ensuring the smoothness of the overall flow. Secondly, the heat-conducting inner barrel, as the core heat transfer component, increases the contact area between the wastewater and the heat medium, making the heat transfer more sufficient and uniform, and promoting the efficient heat absorption of the water in the wastewater. Due to the improvement of fluidity and heat transfer, the water in the wastewater can be more effectively converted into steam during the evaporation process, thereby improving the evaporation efficiency.

[0030] 2. By setting up a stirring and brushing mechanism, the spiral rod can effectively guide the flow of wastewater in a stationary state, reduce turbulence and disorder, improve flow stability, and at the same time increase the contact surface area, enhance heat exchange capacity, and improve thermal efficiency. When the spiral rod is rotating, it continuously disturbs the wastewater in the outer ring channel, effectively breaking the temperature stratification phenomenon, achieving uniform diffusion and efficient absorption of heat. At the same time, the scraping action of the spiral rod during rotation can promptly clean up precipitated salts and other impurities to prevent them from accumulating into stubborn scale, thereby maintaining the thermal efficiency of the equipment, reducing energy consumption and improving the overall operation effect.

[0031] 3. By providing a cleaning mechanism, and by providing a cleaning mechanism and a stirring and brushing mechanism at the bottom of each group of outer ring channels to work together, in the later stage of evaporation and crystallization, the cleaning mechanism uses the power generated by the rotation of the spiral rod to push the precipitated crystal material to the slag discharge port, thereby realizing effective treatment of the crystallized product at the bottom of the outer ring channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1It is a schematic diagram of the three-dimensional structure of the present invention;

[0033] Figure 2 It is a schematic diagram of the front view structure section of the evaporation tank and the sealing cover of the present invention;

[0034] Figure 3 It is a schematic diagram of the front view structure section of the evaporation tank, drainage device, adjustment mechanism, electric push rod and water level sensor of the present invention;

[0035] Figure 4 It is a schematic diagram of the three-dimensional structure of the heat-conducting inner barrel of the present invention;

[0036] Figure 5 It is a schematic cross-sectional view of the three-dimensional structure of the heat-conducting inner barrel of the present invention;

[0037] Figure 6 It is a schematic diagram of the three-dimensional structure of the adjustment mechanism of the present invention;

[0038] Figure 7 It is a schematic diagram of the three-dimensional structure of the adjustment plate, central axis, swing arm, connecting rod and rotating axis of the present invention;

[0039] Figure 8 It is a schematic diagram of the three-dimensional structure of the discharge tube of the present invention;

[0040] Fig. 9 It is a schematic diagram of the front view structure section of the evaporator and the heat-conducting inner barrel of the present invention;

[0041] Fig.10 It is a three-dimensional structural schematic diagram of the connecting column, the fixing plate, the main shaft, the driven gear, the driving gear and the motor of the present invention;

[0042] Fig.11 It is a schematic diagram of the cross-sectional structure of the heat-conducting inner barrel and the spiral rod of the present invention;

[0043] Fig.12 It is a schematic exploded view of the three-dimensional structure of the cleaning mechanism of the present invention;

[0044] Fig.13 It is a schematic diagram of the top view of the heat-conducting inner barrel and the cleaning mechanism of the present invention;

[0045] Fig.14 For the present invention Fig.13 A schematic diagram of the structure enlargement in the middle;

[0046] Fig.15 It is a schematic diagram of the process flow of the present invention.

[0047] In the figure:

[0048] 1. Equipment body; 11. Evaporation tank; 12. Sealing cover; 13. Heating assembly; 14. Steam inlet; 15. Steam outlet; 16. Water inlet; 17. Partition plate; 2. Drainage device; 21. Heat-conducting inner barrel; 22. Inner ring channel; 23. Drain pipe; 24. First water outlet; 25. Outer ring channel; 251. Slag outlet; 252. Slag pipe; 26. Second water outlet; 3. Adjustment mechanism; 31. Discharge tube; 311. Limit plate; 32. Adjustment plate; 33. Center axis; 34. Swing arm; 3 5. Frame; 36. Connecting rod; 37. Rotating shaft; 4. Electric push rod; 5. Water level sensor; 6. Brush stirring mechanism; 61. Screw rod; 62. Connecting plate; 63. Connecting column; 64. Fixed plate; 641. Sliding block; 642. Sliding groove; 65. Main shaft; 66. Driven gear; 67. Driving gear; 68. Motor; 7. Cleaning mechanism; 71. Pushing block; 711. Guide groove; 72. Slotting; 73. Extrusion plate; 74. Rotating shaft; 75. Protruding rod; 76. Torsion spring; 77. Abutting rod. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0050] Reference Figure 1-Figure 2 The present invention provides an evaporation crystallization device based on high-concentration wastewater, including an equipment body 1, the equipment body 1 includes an evaporation tank 11, a sealing cover 12 arranged at the top of the evaporation tank 11, a heating component 13 for heating arranged in the inner wall interlayer of the evaporation tank 11, a steam inlet 14, a steam outlet 15 and a water inlet 16 arranged on the evaporation tank 11, and a partition 17 arranged at the top of the inner wall of the evaporation tank 11. A controller is also arranged outside the evaporation tank 11, and the heating component 13 is electrically connected to the controller.

[0051] Reference Figure 2-Figure 5 , a drainage device 2 is provided in the evaporation tank 11;

[0052] Specifically, the drainage device 2 includes a heat-conducting inner barrel 21 fixed in the evaporation tank 11, an inner ring channel 22 opened in the center of the heat-conducting inner barrel 21, a guide pipe 23 fixed in the inner ring channel 22, and a plurality of groups of outer ring channels 25 opened on the heat-conducting inner barrel 21. The plurality of groups of outer ring channels 25 are opened sequentially from the inside to the outside with the inner ring channel 22 as the center. A first water outlet 24 arranged vertically is opened between the inner ring channel 22 and the adjacent outer ring channels 25. A second water outlet 26 is opened between the remaining outer ring channels 25. The second water outlets 26 arranged high and low between two adjacent groups can avoid the single direction of wastewater directly entering the evaporation tank 11 through the second water outlets 26, so that the wastewater can enter the outer ring channel 25 in sequence through the second water outlets 26, and can be in an S-shaped direction to diffuse and flow to the periphery, so that the wastewater is evenly distributed when passing through each group of outer ring channels 25, thereby maximizing the use of the space in the heat-conducting inner barrel 21.

[0053] The upper and lower ends of the flow guide pipe 23 are through-connected, and the water outlet end of the water inlet 16 is through-connected with the bottom end of the flow guide pipe 23. The wastewater enters the flow guide pipe 23 through the water inlet 16 and flows into the inner ring channel 22, and then flows to the periphery through multiple groups of outer ring channels 25 along the inner ring channel 22 in sequence. Compared with the traditional single-chamber evaporation tank 11, the multi-channel structure allows the wastewater to flow along a specific trajectory, avoiding the disorder and stagnation of the wastewater flow when it is directly injected into the tank in the traditional way. As the salt concentration in the wastewater continues to increase during the evaporation process, crystals begin to precipitate. The multi-channel structure can also play a certain role in restraining and promoting the mixture of wastewater and crystals, so that it will not quickly block the channel and hinder the overall flow, maintain relatively good fluidity, and ensure that heat can be transferred more evenly in the wastewater;

[0054] Secondly, the heat-conducting inner barrel 21 serves as a core heat transfer component. The inner ring channel 22 opened at the center and multiple groups of outer ring channels 25 opened from the inside to the outside with the inner ring channel 22 as the center increase the contact area between the wastewater and the heat-conducting medium to a certain extent, making the heat transfer more sufficient and uniform, and ensuring that the water in the wastewater can absorb heat efficiently.

[0055] During use, the evaporation tank 11 is heated by turning on the heating component 13, and then the wastewater first enters the guide tube 23 through the water inlet 16, and the wastewater flows into the inner ring channel 22 through the guide tube 23. At this time, with the continuous entry of wastewater, the wastewater enters the innermost outer ring channel 25 through the first water outlet 24, and then the wastewater flows to the periphery through multiple groups of outer ring channels 25 in sequence through the second water outlet 26 for evaporation and crystallization. It should be noted that when the wastewater enters the inner ring channel 22 through the guide tube 23, it plays a role of diversion and preheating. When the wastewater passes through the outer ring channel 25 in sequence, it evaporates and crystallizes, and the top of the heat-conducting inner barrel 21 is in an open state, so the steam generated during the evaporation process can be transported outward through the steam outlet 15.

[0056] Reference Figure 5-Figure 8 , a regulating mechanism 3 for regulating the water inflow is provided at the top of the guide pipe 23;

[0057] Specifically, the regulating mechanism 3 includes a discharge tube 31 fixed at the top of the guide tube 23, an adjusting plate 32 arranged in the discharge tube 31 and rotating through the central axis 33, a swing arm 34 fixed at one end of the central axis 33, a frame 35 fixed on the outer wall of the discharge tube 31, and a connecting rod 36 movably penetrating the frame 35, the bottom end of the connecting rod 36 is rotatably connected to the other end of the swing arm 34 through a rotating shaft 37, and the swing arm 34 is controlled by the up and down movement of the connecting rod 36 to drive the central axis 33 to rotate, wherein the central axis 33 is rotatably connected to the discharge tube 31 through a bearing, and the water intake of the discharge tube 31 is flexibly adjusted by controlling the adjustment plate 32 through the rotation of the central axis 33. It should be noted that two sets of limit plates 311 are fixed to the inner wall of the discharge tube 31 and are arranged up and down. The two sets of limit plates 311 are respectively located at the upper and lower positions of the side walls of the adjustment plate 32. Through the setting of the limit plates 311, when the adjustment plate 32 is flipped to a horizontal state, it can play a role in limiting the adjustment plate 32.

[0058] An electric push rod 4 is installed on the partition 17. The electric push rod 4 is installed on the upper surface of the partition 17. The shielding of the partition 17 can prevent the electric push rod 4 from being damaged by steam. The output end of the electric push rod 4 is fixedly connected to the top of the connecting rod 36. A water level sensor 5 is provided above the inner wall of the outermost outer ring channel 25. The electric push rod 4 and the water level sensor 5 are both electrically connected to the controller. When the water level line inside the outermost outer ring channel 25 is higher than the water level sensor 5, the water level sensor 5 transmits a signal to the controller. After receiving the signal, the controller controls the electric push rod 4 to start. After the electric push rod 4 starts, it controls the connecting rod 36 to extend and retract, that is, controls the adjustment plate 32 to rotate and adjust the discharge tube 31. The amount of water inlet, because the excess water not only absorbs a large amount of heat energy but is difficult to vaporize efficiently, but also increases the heat conduction resistance and wastes energy. Therefore, through the coordinated operation of the electric push rod 4 and the water level sensor 5, once the water level of the outermost outer ring channel 25 is higher than the water level sensor 5, the water level sensor 5 can quickly send an instruction to the controller, and the controller controls the electric push rod 4 to start, and then controls the regulating mechanism 3 to adjust the water inlet flow rate, thereby avoiding excessive heating caused by excessive water in the heat-conducting inner barrel 21, and effectively avoiding large fluctuations in the water level in the tank due to excessive or insufficient water inlet, ensuring a stable amount of water vaporization per unit time, and reducing problems such as abnormal crystallization and incomplete reaction caused by fluctuations in steam volume.

[0059] During use, when the water level line inside the outer outer ring channel 25 is higher than the water level sensor 5, the water level sensor 5 transmits a signal to the controller. After receiving the signal, the controller controls the electric push rod 4 to start. After the electric push rod 4 is started, it controls the connecting rod 36 to move downward. The movement of the connecting rod 36 controls the swing arm 34 to drive the central shaft 33 to rotate, and the rotation of the central shaft 33 controls the adjustment plate 32 to adjust the water intake of the discharge tube 31.

[0060] Reference Figure 9-11 , each set of outer ring channels 25 is provided with a stirring and brushing mechanism 6;

[0061] Specifically, the brushing mechanism 6 includes two groups of spiral rods 61 arranged in each group of outer ring channels 25, and the spiral rods 61 are in sliding contact with the inner walls of the outer ring channels 25 respectively. The two groups of spiral rods 61 in each group of outer ring channels 25 can effectively guide the wastewater to flow along a specific path when the spiral rods 61 are stationary, reduce turbulence and disorder in the flow, and improve the stability of the flow. At the same time, it can also increase the surface area in contact with the wastewater, thereby enhancing the heat exchange capacity and improving thermal efficiency.

[0062] Furthermore, the brush stirring mechanism 6 also includes a connecting plate 62 fixed between the top ends of the multiple groups of spiral rods 61, a connecting column 63 fixed on the connecting plate 62, a fixed plate 64 fixed on the connecting column 63, a main shaft 65 fixed on the fixed plate 64, a driven gear 66 fixed on the main shaft 65, and a driving gear 67 meshing with the driven gear 66. By utilizing the meshing of the driven gear 66 and the driving gear 67, the main shaft 65 is controlled to drive the fixed plate 64, the connecting column 63, the connecting plate 62 and the multiple groups of spiral rods 61 to rotate, and the main shaft 65 is located at the center of the heat-conducting inner barrel 21, so the spiral rod 61 can rotate along the inner side wall of the outer ring channel 25 with the main shaft 65 as the center. It should be noted that a slider 641 is fixed on the fixed plate 64, and an annular groove 642 for the slider 641 to slide is provided on the partition 17. The cooperation of the slider 641 and the groove 642 can guide the rotation of the fixed plate 64.

[0063] The main shaft 65 passes through the partition 17 and the sealing cover 12 in sequence. A motor 68 is installed on the sealing cover 12 through a bracket. The output end shaft of the motor 68 is fixedly connected to the driving gear 67. The motor 68 is electrically connected to the controller. After the motor 68 is started, the driving gear 67, the driven gear 66 and the main shaft 65 are controlled to rotate, so that the multiple groups of spiral rods 61 rotate along the inner side wall of the corresponding outer ring channel 25 with the main shaft 65 as the center. Through the rotation of the spiral rods 61, the wastewater in the outer ring channel 25 can be continuously disturbed, breaking the temperature stratification phenomenon that may be formed due to uneven heating. The wastewater is pushed by the spiral rods 61. Under the movement, it can roll and mix quickly, so that the heat can be diffused in the water body more evenly and efficiently, ensuring that the entire water body can fully absorb the heat from the heating component 13 and the steam heat injected from the steam inlet 14, thereby accelerating the evaporation efficiency of the wastewater. At the same time, during the evaporation and concentration process of the wastewater, impurities such as salts are easy to crystallize and adhere to the wall to form a scale layer, which hinders heat transfer. The spiral rod 61 slidingly fitted on the inner wall of the outer ring channel 25 can clean the newly precipitated tiny crystals in time through the scraping action when rotating, preventing them from growing and accumulating into stubborn scale, thereby reducing the problems of reduced thermal efficiency and increased energy consumption of equipment caused by scaling.

[0064] During use, the motor 68 is started to control the rotation of the driving gear 67, and the meshing of the driving gear 67 and the driven gear 66 is used to rotate the main shaft 65, thereby controlling the rotation of the fixed plate 64, the connecting column 63, the connecting plate 62 and the multiple groups of spiral rods 61, so that the multiple groups of spiral rods 61 rotate around the main shaft 65 along the inner wall of the corresponding outer ring channel 25, thereby disturbing the wastewater in the outer ring channel 25 and descaling the inner wall of the outer ring channel 25.

[0065] Reference Figure 11-Figure 14 , a cleaning mechanism 7 is provided at the bottom end of the inner wall of each set of outer ring channels 25;

[0066] Specifically, the cleaning mechanism 7 includes a push block 71 fixed between the bottom ends of the two sets of spiral rods 61, a slot 72 provided on the push block 71, a squeeze plate 73 provided in the slot 72 rotated by a rotating shaft 74, a convex rod 75 fixed on the rotating shaft 74, and a torsion spring 76 provided on the rotating shaft 74. A push block 71 is fixed between the bottom ends of the two sets of spiral rods 61 provided in each set of outer ring channels 25, and the bottom of the push block 71 is in sliding contact with the bottom end of the inner wall of the corresponding outer ring channel 25. The bottom end of each group of outer ring channels 25 is connected with a slag discharge port 251, and each group of slag discharge ports 251 is provided with a discharge valve. The bottom ends of the multiple groups of slag discharge ports 251 are connected with an inclined slag discharge pipe 252, and one end of the slag discharge pipe 252 passes through the outside of the evaporator 11. A contact rod 77 corresponding to the convex rod 75 is fixed on the side wall of each group of outer ring channels 25, and the contact rod 77 is arranged on the rotation path of the push block 71 and close to the slag discharge port 251.

[0067] It should be noted that the slag discharge port 251 is arranged on the right side of the bottom end of each group of outer ring channels 25, the slot 72 is arranged on the front side of each group of pushing blocks 71, and the rotating shaft 74 is rotatably connected to the right side of the inner wall of each group of slots 72 through a bearing. The specific position can be referred to Figure 13-Figure 14 of the heating component. When the two groups of spiral rods 61 in each group of outer ring channels 25 rotate clockwise around the main shaft 65, the pushing block 71, the slot 72, the extrusion plate 73, the rotating shaft 74, the protruding rod 75 and the torsion spring 76 can be driven to rotate clockwise as a whole, thereby pushing the crystals scraped off by the spiral rod 61. When the crystals are pushed to a position close to the slag discharge port 251, the protruding rod 75 can control the rotating shaft 74 to drive the extrusion plate 73 to flip through the abutment with the abutment rod 77, thereby squeezing the crystals, so that the crystals can quickly pass through the slag discharge port 251 and finally be collected in the slag discharge pipe 252 for outward transportation.

[0068] Among them, the ends of the abutment rod 77 and the protruding rod 75 that are close to each other are both arc-shaped. The arc-shaped setting facilitates the contact between the abutment rod 77 and the protruding rod 75, and a guide groove 711 for the protruding rod 75 to rotate is provided on the pushing block 71. When the protruding rod 75 rotates after abutting against the abutment rod 77, it can rotate stably along the provided guide groove 711.

[0069] Furthermore, the torsion spring 76 is arranged at the upper and lower ends of the rotating shaft 74, and a notch is opened on the extrusion plate 73 for the torsion spring 76 to twist. The two ends of the torsion spring 76 are respectively fixed to the inner wall of the notch and the inner wall of the slot 72. When the protruding rod 75 is separated from the abutment with the abutment rod 77, the rotating shaft 74 can control the extrusion plate 73 to automatically reset again under the control of the torsion force of the torsion spring 76.

[0070] By arranging a cleaning mechanism 7 and a brushing mechanism 6 at the bottom of each group of outer ring channels 25 to work together, in the later stage of evaporation and crystallization, a large amount of crystallized products are often accumulated at the bottom of the outer ring channel 25. The rotation of the screw rod 61 can prevent the crystals from hardening and maintain their loose state for subsequent processing. On the other hand, the cleaning mechanism 7 uses the power generated by the rotation of the screw rod 61 to accurately push the precipitated and accumulated crystallized materials to the slag discharge port 251 along a predetermined route to realize automatic discharge.

[0071] During use, when it is necessary to discharge the crystals in the outer ring channel 25, first open the discharge valve on the slag discharge port 251, and then, the spiral rod 61 rotates clockwise around the main shaft 65, while driving the push block 71, the slot 72, the extrusion plate 73, the rotating shaft 74, the protruding rod 75 and the torsion spring 76 to rotate clockwise as a whole. The rotation of the push block 71 can push the crystals scraped off by the spiral rod 61. When the crystals are pushed to a position close to the slag discharge port 251, the protruding rod 75 abuts against the abutting rod 77. During the abutting process, the protruding rod 75 controls the rotating shaft 74 to drive the extrusion plate 73 to flip, thereby squeezing the crystals, so that the crystals can quickly pass through the slag discharge port 251 and finally gather in the slag discharge pipe 252 for outward transportation.

[0072] Reference Fig.15 The present invention also provides a zero-discharge process based on high-concentration wastewater, using an evaporation crystallization device, comprising the following steps:

[0073] S1: pretreatment step, the high-concentration wastewater first enters the regulating tank, the pH of the wastewater is adjusted to a predetermined range in the regulating tank, an appropriate amount of flocculant is added for flocculation and precipitation, and suspended impurities and some macromolecular organic matter in the wastewater are removed. The supernatant after precipitation is transported to the water inlet 16 of the evaporation crystallization device through a lift pump;

[0074] S2: Evaporation and crystallization step, the pretreated wastewater enters the guide tube 23 in the heat-conducting inner barrel 21 of the evaporation and crystallization device through the water inlet 16, and then flows to the periphery through multiple groups of outer ring channels 25 along the inner ring channel 22 opened in the center. Under the heating action of the heating component 13, the wastewater enters the outer ring channel 25 along the inner ring channel 22 and flows outward in sequence. The water gradually evaporates and the solute concentration continues to increase. During the flow process, the stirring and brushing mechanism 6 continues to operate to keep the wastewater in good fluidity, promote uniform evaporation and crystallization, and the water vapor generated by evaporation rises and enters the gas-liquid separation device through the steam outlet 15;

[0075] S3: Gas-liquid separation and condensation recovery step. After the water vapor enters the gas-liquid separation device, it is subjected to cyclone separation and wire mesh defoaming treatment to remove the entrained tiny droplets. The separated pure water vapor enters the condensation recovery unit. Through the heat exchange effect of the cooling water pipeline in the condenser, the water vapor is condensed into liquid water and recovered to the clean water storage tank for industrial reuse or standard discharge.

[0076] S4: solid discharging step. After the solid material crystallized in the main body of the evaporation crystallization tank reaches a certain amount, the discharging valve of the slag discharge port 251 is opened, and the solid crystals are scraped off by rotating the screw rod 61, and the pushing block 71 is rotated to make the extrusion plate 73 squeeze and push the material, so that the scraped solid crystals are transported outward through the slag discharge port 251 and the slag discharge pipe 252, and then the subsequent drying and packaging processes, or purification and other deep treatments are carried out to achieve the goal of zero discharge of high-concentration wastewater.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An evaporation crystallization device based on high-concentration wastewater, comprising an equipment body (1), characterized in that: The device body (1) comprises an evaporation tank (11), a sealing cover (12) arranged at the top of the evaporation tank (11), a heating component (13) arranged in an inner wall interlayer of the evaporation tank (11), a steam inlet (14), a steam outlet (15) and a water inlet (16) arranged on the evaporation tank (11), and a partition (17) arranged at the top of the inner wall of the evaporation tank (11); a controller is also arranged outside the evaporation tank (11); The evaporation tank (11) is provided with a drainage device (2); The flow guide device (2) comprises a heat-conducting inner barrel (21) fixed in the evaporation tank (11), an inner ring channel (22) opened in the center of the heat-conducting inner barrel (21), a flow guide pipe (23) fixed in the inner ring channel (22), and a plurality of groups of outer ring channels (25) opened on the heat-conducting inner barrel (21), the plurality of groups of outer ring channels (25) being opened in sequence from the inside to the outside with the inner ring channel (22) as the center, and a first water outlet (24) being opened in an upper and lower arrangement between the inner ring channel (22) and an adjacent outer ring channel (25), Second water outlets (26) are provided between the remaining outer ring channels (25), and two adjacent groups of second water outlets (26) are arranged at different heights. A regulating mechanism (3) for regulating the amount of water inlet is provided at the top of the guide pipe (23). The water outlet end of the water inlet (16) is connected to the bottom end of the guide pipe (23). Wastewater enters the guide pipe (23) through the water inlet (16) and flows into the inner ring channel (22), and then flows toward the periphery along the inner ring channel (22) through the plurality of groups of outer ring channels (25) in sequence. Each group of the outer ring channels (25) is provided with a stirring and brushing mechanism (6); The stirring and brushing mechanism (6) comprises two groups of spiral rods (61) arranged in each group of outer ring channels (25), and the spiral rods (61) are respectively in sliding contact with the inner side walls of the outer ring channels (25).

2. The evaporation and crystallization device based on high-concentration wastewater according to claim 1 is characterized in that: The regulating mechanism (3) comprises a discharge tube (31) fixed at the top end of the flow guide tube (23), an regulating plate (32) arranged in the discharge tube (31) and rotatable through a central axis (33), a swing arm (34) fixed at one end of the central axis (33), a frame (35) fixed on the outer wall of the discharge tube (31), and a connecting rod (36) movably penetrating the frame (35), wherein the connecting rod (36) is rotatably connected to the swing arm (34) through a rotating shaft (37); An electric push rod (4) is installed on the partition (17), and the output end of the electric push rod (4) is fixedly connected to the connecting rod (36), wherein a water level sensor (5) is provided above the inner wall of the outermost outer ring channel (25), and the electric push rod (4) and the water level sensor (5) are both electrically connected to the controller. When the water level line inside the outermost outer ring channel (25) is higher than the water level sensor (5), the water level sensor (5) transmits a signal to the controller, and the controller controls the electric push rod (4) to start after receiving the signal, so that the adjustment plate (32) rotates to adjust the water inflow of the discharge tube (31).

3. The evaporation and crystallization device based on high-concentration wastewater according to claim 1 is characterized in that: The agitating brush mechanism (6) further comprises a connecting plate (62) fixed between the plurality of sets of spiral rods (61), a connecting column (63) fixed on the connecting plate (62), a fixing plate (64) fixed on the connecting column (63), a main shaft (65) fixed on the fixing plate (64), a driven gear (66) fixed on the main shaft (65), and a driving gear (67) meshing with the driven gear (66); A motor (68) is mounted on the sealing cover (12) via a bracket. The output end shaft of the motor (68) is fixedly connected to the driving gear (67). The motor (68) is electrically connected to a controller. When the motor (68) is started, it controls the main shaft (65) to rotate, so that the multiple groups of spiral rods (61) rotate along the inner wall of the outer ring channel (25) with the main shaft (65) as the center.

4. The evaporation and crystallization device based on high-concentration wastewater according to claim 3 is characterized in that: A cleaning mechanism (7) is provided at the bottom end of the inner wall of each group of the outer ring channels (25), the cleaning mechanism (7) comprising a pushing block (71) fixed between the bottom ends of the two groups of spiral rods (61), a slot (72) provided on the pushing block (71), an extrusion plate (73) provided in the slot (72) and rotated by a rotating shaft (74), a protruding rod (75) fixed on the rotating shaft (74), and a torsion spring (76) provided on the rotating shaft (74); The bottom end of each group of the outer ring channels (25) is connected through a slag discharge port (251), and the bottom ends of the multiple groups of the slag discharge ports (251) are connected through an inclined slag discharge pipe (252), and an abutment rod (77) corresponding to the protruding rod (75) is fixed on the side wall of each group of the outer ring channels (25), and the abutment rod (77) is arranged on the rotation path of the push block (71) and close to the slag discharge port (251).

5. The evaporation and crystallization device based on high-concentration wastewater according to claim 4 is characterized in that: The ends of the abutting rod (77) and the protruding rod (75) that are close to each other are both arranged in an arc shape.

6. The evaporation and crystallization device based on high-concentration wastewater according to claim 4 is characterized in that: The pushing block (71) is provided with a guide groove (711) for the protruding rod (75) to rotate.

7. The evaporation and crystallization device based on high-concentration wastewater according to claim 4 is characterized in that: The torsion spring (76) is arranged at the upper and lower ends of the rotating shaft (74), and the extrusion plate (73) is provided with a notch for the torsion spring (76) to twist.

8. The evaporation and crystallization device based on high-concentration wastewater according to claim 3 is characterized in that: A sliding block (641) is fixed on the fixed plate (64), and an annular sliding groove (642) for the sliding block (641) to slide is provided on the partition plate (17).

9. The evaporation and crystallization device based on high-concentration wastewater according to claim 2 is characterized in that: Two sets of limiting plates (311) arranged opposite to each other are fixed on the inner wall of the discharge tube (31), and the two sets of limiting plates (311) are arranged up and down, and the two sets of limiting plates (311) are respectively located at the upper and lower positions of the side wall of the adjustment plate (32).

10. A zero-discharge process based on high-concentration wastewater, using the evaporation crystallization device according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: pretreatment step, the high-concentration wastewater first enters the regulating tank, the pH of the wastewater is adjusted to a predetermined range in the regulating tank, an appropriate amount of flocculant is added for flocculation and precipitation, and suspended impurities and some macromolecular organic matter in the wastewater are removed. The supernatant after precipitation is transported to the water inlet (16) of the evaporation crystallization device through a lifting pump; S2: Evaporation and crystallization step, the pre-treated wastewater enters the guide tube (23) in the heat-conducting inner barrel (21) of the evaporation and crystallization device through the water inlet (16), and then flows toward the periphery along the inner ring channel (22) opened in the center through multiple groups of outer ring channels (25). Under the heating action of the heating component (13), the wastewater enters the outer ring channel (25) along the inner ring channel (22) and flows outward in sequence, the water gradually evaporates, and the solute concentration continues to increase. During the flow process, the stirring and brushing mechanism (6) continues to operate to keep the wastewater in good fluidity, promote uniform evaporation and crystallization, and the water vapor generated by evaporation rises and enters the gas-liquid separation device through the steam outlet (15); S3: Gas-liquid separation and condensation recovery step. After the water vapor enters the gas-liquid separation device, it is subjected to cyclone separation and wire mesh defoaming treatment to remove the entrained tiny droplets. The separated pure water vapor enters the condensation recovery unit. Through the heat exchange effect of the cooling water pipeline in the condenser, the water vapor is condensed into liquid water and recovered to the clean water storage tank for industrial reuse or standard discharge. S4: solid discharge step. When the solid material crystallized in the evaporation crystallization tank body reaches a certain amount, the discharge valve of the slag discharge port (251) is opened, and the solid crystals are scraped off by rotating the screw rod (61). The pushing block (71) is rotated to make the extrusion plate (73) squeeze and push the material, so that the scraped solid crystals are transported outward through the slag discharge port (251) and the slag discharge pipe (252), and then the subsequent drying and packaging processes are carried out, or deep treatment such as purification is carried out to achieve the goal of zero discharge of high-concentration wastewater.

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