Energy-saving continuous evaporation and crystallization equipment for wastewater

Abstract

The present application relates to the technical field of wastewater continuous evaporation crystallization, and relates to an energy-saving wastewater continuous evaporation crystallization device, which comprises a device frame, and three evaporation cavities are arranged in the evaporation cylinder in a vertical distribution manner; a heat exchange assembly for heating wastewater is arranged in each evaporation cavity; a plurality of heat exchange pipes are in plug connection with the inside of the bottom end of the upper heat exchange disc; a spiral disturbance assembly is arranged in the heat exchange pipe; a spiral blade is fixedly arranged on the outside of the connecting shaft; and a wastewater circulation assembly is arranged on the inside and outside of the evaporation cylinder. The steam compression assembly, the heat exchange assembly and the pipeline are arranged, so that secondary steam generation-purification-compression-heat exchange-circulation full closed loop is realized; the secondary steam purified by the demisting module is pressurized and heated to high-grade steam by the MVR compressor, is stabilized by the steam buffer tank, is introduced into the heat exchange assembly to heat the wastewater, and the condensed liquid after heat exchange is recycled; the excess steam is treated by the condenser and is recycled, so that direct discharge of the secondary steam is avoided.

Description

Technical Field

[0001] This invention relates to the field of continuous evaporation and crystallization technology for wastewater, specifically to an energy-saving continuous evaporation and crystallization equipment for wastewater. Background Technology

[0002] Wastewater continuous evaporation crystallization equipment is a continuous industrial water treatment system that integrates evaporation concentration, supersaturated crystallization, solid-liquid separation, and condensate recovery. Its core is to continuously evaporate wastewater under vacuum / low temperature conditions, so that the solute reaches supersaturation and crystallizes out stably. At the same time, it realizes the resource reuse of water and the harmless disposal or recycling of solid salt residue.

[0003] A search revealed a multifunctional, energy-saving continuous evaporation crystallization equipment for wastewater, application number 201610018300.1. This equipment includes a waste liquid treatment device, a steam heating device, a condensate recovery device, a cooling water circulation device, and a non-condensable gas treatment device. The waste liquid treatment device is equipped with these devices. The equipment further includes a raw liquid tank, a raw liquid transfer pump, a primary preheater, a secondary preheater, an inlet pipe, a triple-effect heater, a triple-effect separator, a triple-effect forced circulation pump, a circulation pipe, an outlet pipe, a second-effect heater, a second-effect separator, a second-effect forced circulation pump, a first-effect heater, a first-effect separator, a first-effect forced circulation pump, a crystallization tank, a centrifuge, and a reflux pump. This invention optimizes the number of effects, minimizes the heat exchange area, and maximizes the evaporation intensity.

[0004] Traditional wastewater evaporation crystallization equipment relies on external fresh steam (mostly live steam from boilers) for heating. Its working principle involves introducing fresh steam into a heat exchanger, transferring heat to the wastewater, causing it to boil and evaporate, thus achieving concentration and crystallization. However, this type of equipment suffers from severe heat waste. During wastewater evaporation, a large amount of secondary steam (low-grade steam formed after the wastewater boils and evaporates, containing a significant amount of latent heat) is generated. Traditional equipment lacks an effective secondary steam recovery and utilization structure, directly cooling and discharging this secondary steam through a condenser, resulting in complete waste of the latent heat and preventing heat recycling. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving wastewater continuous evaporation crystallization device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an energy-saving wastewater continuous evaporation crystallization device, comprising a device frame and an evaporation cylinder fixedly installed inside the device frame, and further comprising: three vertically distributed evaporation chambers are opened inside the evaporation cylinder, each of the evaporation chambers is provided with a heat exchange component for heating wastewater, the heat exchange component includes a heat exchange shell fixedly installed inside the evaporation chamber, an upper heat exchange plate is fixedly installed on the upper side inside the heat exchange shell, and multiple heat exchange tubes are inserted and connected inside the bottom end of the upper heat exchange plate; The heat exchange tube is equipped with a spiral disturbance component. The spiral disturbance component includes a fixed shaft fixedly installed inside the upper end of the heat exchange tube, a spring fixedly installed in the middle of the fixed shaft, a connecting shaft fixedly installed at the bottom end of the spring, and spiral blades fixedly installed on the outside of the connecting shaft. A wastewater circulation component is provided both inside and outside the evaporation cylinder.

[0007] Preferably, adjacent evaporation chambers are separated by partition plates. The upper end face of the partition plate is designed as a conical surface. A connecting pipe is fixedly installed in the middle position of the two upper partition plates. A control valve is installed on the wall of the connecting pipe. A concentrated liquid compliance detection valve pipe is installed on the bottom partition plate. A concentration sensor is embedded in the upper end face of the partition plate.

[0008] Preferably, a waste liquid conveying assembly is provided on the outer wall of the evaporation cylinder. The waste liquid conveying assembly includes a conveying pump fixed to the outer wall of the evaporation cylinder. The input end of the conveying pump is fixedly connected to a conveying pipe, and the output end of the conveying pump is fixedly connected to a wastewater conveying main pipe. The output end of the wastewater conveying main pipe is fixedly connected to multiple wastewater conveying manifolds, and the output end of the wastewater conveying manifolds is interconnected with the interior of the evaporation chamber.

[0009] Preferably, a vacuum assembly is provided on the outside of the evaporation cylinder. The vacuum assembly includes a vacuum pump fixedly installed on the equipment frame. One end of the vacuum pump is fixedly connected to a buffer tank. One end of the buffer tank is fixedly connected to a vacuum main pipe. Three vacuum manifolds are fixedly connected to the vacuum main pipe. The ends of the three vacuum manifolds are interconnected with the interior of the evaporation chamber.

[0010] Preferably, a vapor compression assembly is provided at the upper end of the equipment rack. The vapor compression assembly includes an MVR vapor compressor fixedly installed on one side of the equipment rack. The input end of the MVR vapor compressor is fixedly connected to a vapor collection manifold. The input end of the vapor collection manifold is fixedly connected to three vapor collection manifolds. The input end of the vapor collection manifolds extends into the interior of the evaporation chamber. A demisting module is fixedly installed at the input end of the vapor collection manifolds.

[0011] Preferably, the output end of the MVR steam compressor is connected to a steam buffer tank, the output end of the steam buffer tank is connected to a condenser and a steam discharge manifold, the output end of the steam discharge manifold is connected to three steam discharge manifolds, and the end of the steam discharge manifold penetrates the outer wall of the evaporator and communicates with the interior of the heat exchange shell.

[0012] Preferably, the wastewater circulation assembly includes a main circulation pump fixedly installed on the side wall of the evaporator. The input end of the main circulation pump is connected to a main circulation suction pipe. The input end of the main circulation suction pipe passes through the evaporator and is connected to the bottom end of the bottommost evaporation chamber. The output end of the main circulation pump is connected to a main circulation discharge pipe. The end of the main circulation discharge pipe passes through the evaporator and is connected to the top end of the topmost evaporation chamber.

[0013] Preferably, the wastewater circulation assembly further includes three secondary circulation pumps fixedly installed on the side wall of the evaporator. The output end of the secondary circulation pump is connected to a secondary circulation discharge pipe. The output end of the secondary circulation discharge pipe passes through the evaporator, the heat exchange shell and the upper heat exchange plate and communicates with each other. The input end of the secondary circulation pump is connected to a secondary circulation suction pipe.

[0014] Preferably, the heat exchange tubes are designed with a large diameter, and the diameter of the heat exchange tubes in each heat exchange assembly decreases progressively from top to bottom. A lower heat exchange plate is fixedly installed on the lower side of the heat exchange shell. The lower heat exchange plate and the upper heat exchange plate are interconnected by several heat exchange tubes. A drain pipe that penetrates the bottom end face of the heat exchange shell is fixedly connected to the middle position of the lower heat exchange plate. A non-condensable liquid discharge port is fixedly connected to the bottom end of the heat exchange shell. Three sets of parallel fixed baffles are fixedly installed inside the heat exchange shell, and the fixed baffles have connecting holes inside.

[0015] Preferably, the inner wall of the evaporation cylinder is equipped with three sets of temperature sensors, liquid level sensors, and vacuum sensors corresponding to the evaporation chamber. The bottom end of the evaporation cylinder is connected to a multi-stage conical crystallizer, and the bottom end of the multi-stage conical crystallizer is connected to a cyclone centrifugal mechanism.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves a closed-loop process of secondary steam generation, purification, compression, heat exchange, and circulation by setting up a steam compression component, a heat exchange component, and pipelines. The secondary steam, purified by the demisting module, is pressurized and heated into high-grade steam by the MVR compressor. After being stabilized by the steam buffer tank, it is introduced into the heat exchange component to heat wastewater. The condensate after heat exchange is recycled. Excess steam is treated by the condenser and then recovered, preventing direct discharge of secondary steam. The steam buffer tank buffers and stabilizes the pressure, and in conjunction with the sensor and PLC control system, it controls the MVR compressor speed and condenser opening in real time to maintain stable steam parameters. At the same time, it optimizes feed control and pipeline protection to reduce fluctuations in secondary steam intake and avoid energy loss and equipment failure.

[0017] This invention utilizes a fixed baffle to make steam flow in an S-shape, extending the residence time; a spiral turbulence component is linked with a variable frequency secondary circulation pump to form a spiral pulsating flow, improving the uniformity of wastewater heat exchange and online descaling; the heat exchange tube diameter is optimized according to the wastewater viscosity to promptly discharge non-condensable gases and reduce steam heat loss; a vacuum component is linked with sensors to precisely control the vacuum gradient of each evaporation chamber, reducing the wastewater evaporation temperature; a buffer tank, demister filter, check valve, and other structures maintain vacuum stability, protect the vacuum pump, and reduce operating energy consumption; the valves, pumps, and sensors related to steam circulation and heat exchange are all linked with the PLC control system to automatically adjust steam circulation parameters and maintain heat exchange efficiency, avoiding steam waste and increased energy consumption caused by untimely manual control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure in this invention; Figure 2 This is a schematic diagram of the evaporator structure in this invention; Figure 3 This is a schematic diagram of the internal structure of the evaporator cylinder in this invention; Figure 4 This is a schematic diagram of the internal structure of the heat exchange shell in this invention; Figure 5 This is a schematic diagram of the spiral disturbance component structure in this invention; Figure 6 This is a schematic diagram of the wastewater recycling component structure in this invention; Figure 7 This is a schematic cross-sectional view of the partition plate in this invention; Figure 8 This is a schematic diagram of the distribution structure of the three heat exchange components in this invention; Figure 9 This is a schematic diagram of the vapor compression assembly structure in this invention.

[0019] In the diagram: 1. Equipment rack; 2. Evaporator; 201. Evaporation chamber; 202. Divider plate; 203. Connecting pipe; 204. Control valve; 205. Concentration sensor; 206. Concentrate compliance detection valve pipe; 3. Waste liquid conveying assembly; 301. Conveying pipe; 302. Conveying pump; 303. Wastewater conveying main pipe; 304. Wastewater conveying manifold; 4. Vacuum assembly; 401. Vacuum pump; 402. Buffer tank; 403. Vacuum main pipe; 404. Vacuum manifold; 5. Vacuum compression assembly; 501. MVR vapor compressor; 502. Vacuum buffer tank; 503. Condenser; 504. Vacuum collection main pipe; 505. Vacuum collection manifold; 506. Vacuum discharge main pipe; 507. Vacuum discharge manifold; 6. 1. Wastewater circulation assembly; 601. Main circulation pump; 602. Main circulation suction pipe; 603. Main circulation discharge pipe; 604. Secondary circulation pump; 605. Secondary circulation discharge pipe; 606. Secondary circulation suction pipe; 7. Heat exchange assembly; 701. Heat exchange shell; 702. Upper heat exchange plate; 703. Fixed baffle plate; 704. Connecting hole; 705. Lower heat exchange plate; 706. Drain pipe; 707. Heat exchange tube; 708. Non-condensable liquid discharge port; 8. Demisting module; 9. Spiral disturbance assembly; 901. Fixed shaft; 902. Spring; 903. Connecting shaft; 904. Spiral blades; 10. Temperature sensor; 11. Liquid level sensor; 12. Vacuum sensor; 13. Multi-stage conical crystallizer; 14. Cyclone centrifuge mechanism. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0021] Please see Figures 1-9As shown, an energy-saving continuous evaporation crystallization device for wastewater includes a frame 1 and an evaporation cylinder 2 fixedly installed inside the frame 1. The frame 1 is also equipped with an electrical control device, which controls the automatic operation of the device. The device further includes three vertically distributed evaporation chambers 201 inside the evaporation cylinder 2, separated by partition plates 202. The upper surface of each partition plate 202 is tapered, and a connecting pipe 2 is fixedly installed between the two upper partition plates 202. 03. A control valve 204 is installed on the wall of the connecting pipe 203. A concentrated liquid compliance detection valve pipe 206 is installed on the bottom partition plate 202. A concentration sensor 205 is embedded inside the upper end face of the partition plate 202. Three sets of temperature sensors 10, liquid level sensors 11, and vacuum sensors 12 corresponding to the evaporation chambers 201 are embedded on the inner wall of the evaporation cylinder 2. Each evaporation chamber 201 is equipped with a heat exchange assembly 7 for heating wastewater. The heat exchange assembly 7 includes components fixedly installed in the evaporation chamber 201. The heat exchange shell 701 inside the 01 has an upper heat exchange plate 702 fixedly installed on its upper side. Multiple heat exchange tubes 707 are inserted and connected to the bottom of the upper heat exchange plate 702. The heat exchange tubes 707 are designed with a large diameter, and the diameter of the heat exchange tubes 707 in each stage of the heat exchange assembly 7 gradually decreases from top to bottom. A lower heat exchange plate 705 is fixedly installed on the lower side of the heat exchange shell 701. The lower heat exchange plate 705 is interconnected with the upper heat exchange plate 702 through several heat exchange tubes 707. A drain pipe 706 is fixedly connected in the middle position, penetrating the bottom end face of the heat exchange shell 701. A non-condensable liquid discharge port 708 is fixedly connected at the bottom end of the heat exchange shell 701. Three sets of parallel fixed baffles 703 are fixedly installed inside the heat exchange shell 701. A connecting hole 704 is opened inside the fixed baffle 703. It should be noted that, according to the usage requirements, the input end of the heat exchange shell 701 can also be connected to an initial valve pipe. The initial valve pipe is connected to an external auxiliary heat source for preheating the heat exchange medium in the heat exchange assembly 7. The heat exchange tube 707 is equipped with a spiral disturbance component 9. The spiral disturbance component 9 includes a fixed shaft 901 fixedly installed inside the upper end of the heat exchange tube 707, a spring 902 fixedly installed in the middle position of the fixed shaft 901, a connecting shaft 903 fixedly installed at the bottom end of the spring 902, and a spiral blade 904 fixedly installed on the outside of the connecting shaft 903. The evaporator 2 is equipped with a wastewater circulation assembly 6 both inside and outside. The wastewater circulation assembly 6 includes a main circulation pump 601 fixedly installed on the side wall of the evaporator 2. The input end of the main circulation pump 601 is connected to a main circulation suction pipe 602. The input end of the main circulation suction pipe 602 passes through the evaporator 2 and is connected to the bottom end of the bottommost evaporation chamber 201. The output end of the main circulation pump 601 is connected to a main circulation discharge pipe 603. The end of the main circulation discharge pipe 603 passes through the evaporator 2 and is connected to the top end of the topmost evaporation chamber 201. The wastewater circulation assembly 6 also includes three secondary circulation pumps 604 fixedly installed on the side wall of the evaporator 2. The output end of the secondary circulation pump 604 is connected to a secondary circulation discharge pipe 605. The output end of the secondary circulation discharge pipe 605 passes through the evaporator 2, the heat exchange shell 701, and is connected to the upper heat exchange plate 702. The input end of the secondary circulation pump 604 is connected to a secondary circulation suction pipe 606. A waste liquid conveying assembly 3 is provided on the outer wall of the evaporation cylinder 2. The waste liquid conveying assembly 3 includes a conveying pump 302 fixed on the outer wall of the evaporation cylinder 2. The input end of the conveying pump 302 is fixedly connected to a conveying pipe 301, and the output end of the conveying pump 302 is fixedly connected to a wastewater conveying main pipe 303. The output end of the wastewater conveying main pipe 303 is fixedly connected to multiple wastewater conveying manifolds 304. The output end of the wastewater conveying manifolds 304 is interconnected with the interior of the evaporation chamber 201.

[0022] By adopting the above technical solution, a control system for controlling the operation of the entire equipment is also fixedly installed on the equipment frame 1. When the equipment is working, the waste liquid conveying component 3 is started, and the conveying pump 302 draws the wastewater to be treated through the conveying pipe 301. The wastewater is then diverted to three wastewater conveying manifolds 304 through the wastewater conveying main pipe 303, and the wastewater is respectively conveyed to the three vertically distributed evaporation chambers 201 in the evaporation cylinder 2, so as to realize the synchronous feeding of the three evaporation chambers 201. After the wastewater enters each evaporation chamber 201, the liquid level sensor 11 monitors the liquid level in real time. When the liquid level reaches the preset value, a feedback signal is sent to the control system to adjust the speed of the conveying pump 302 or turn it off to stop feeding, so as to ensure that the initial liquid level of each evaporation chamber 201 is consistent, laying the foundation for subsequent staged evaporation and liquid seal formation. The partition plate 202 adopts a conical surface design to facilitate the convergence of liquid. The control valve 204 on the connecting pipe 203 in the middle position is in the initial adjustment state, preparing for the subsequent staged flow of wastewater. At the same time, the opening of the control valve 204 is preset to initially... To control the flow rate of the interstage liquid, it should be noted that during operation, a concentration sensor 205 (synchronously linked with the liquid level sensor 11 and temperature sensor 10) installed at the bottom of each evaporation chamber 201 monitors the concentration of the waste liquid in each evaporation chamber 201 in real time and feeds back the signal to the control system. Based on the concentration gradient fed back by the concentration sensor 205 and combined with the signal from the liquid level sensor 11, the opening of the connecting pipe 203 is automatically adjusted to ensure that the wastewater staged flow rate matches the concentration progress. At the same time, the concentrate compliance detection valve pipe 206 at the bottom of the lowest evaporation chamber 201 is linked with the concentration sensor 205. When the concentrate concentration reaches the preset compliance value, the detection valve automatically opens, transporting the concentrate to the multi-stage conical crystallizer 13. The concentrate that does not meet the standard continues to participate in the main circulation, avoiding insufficient or excessive concentration. The speed of the main circulation pump 601 is linked with the concentration sensor 205 of the lowest evaporation chamber 201. When the concentration is too high, the speed is increased to accelerate the circulation speed; when the concentration is too low, the speed is reduced to reduce energy consumption. When heat exchange is performed on the wastewater inside the equipment, three secondary circulation pumps 604 start simultaneously, drawing wastewater from the corresponding evaporation chamber 201 through the secondary circulation suction pipe 606. It should be noted that the secondary circulation suction pipe 606 extends to the lower middle part of the corresponding evaporation chamber 201 (avoiding the bottom crystallization and sedimentation area), and a stainless steel filter screen (50-80 mesh) is fixedly installed at the inlet end of the secondary circulation suction pipe 606 to intercept crystalline particles and large-diameter impurities in the wastewater, preventing impurities from entering the secondary circulation pump 604 and causing wear. Simultaneously, a small buffer can be installed in series on the secondary circulation suction pipe 606 according to usage requirements to alleviate suction pressure fluctuations, prevent the secondary circulation pump 604 from running dry or experiencing cavitation, and ensure uniform and stable secondary circulation feed to each evaporation chamber 201. The wastewater is then transported through the secondary circulation discharge pipe 605 to the upper heat exchange plate 702 inside the heat exchange shell 701. Wastewater is evenly introduced into each heat exchange tube 707 via the upper heat exchange plate 702, allowing it to fully contact and exchange heat with the high-temperature steam outside each heat exchange tube 707. Three sets of fixed baffles 703 and connecting holes 704 inside the heat exchange shell 701 are used to change the flow direction of hot steam inside the heat exchange shell 701 and outside the heat exchange tubes 707. The connecting holes 704 are located in half of each fixed baffle 703, and the connecting holes 704 on adjacent fixed baffles 703 are obliquely symmetrically distributed, causing the hot steam to flow in an S-shape, extending the residence time of the steam in the heat exchange shell 701, and improving the heat exchange efficiency between the hot steam and the heat exchange tubes 707. After heat exchange is completed inside the heat exchange tubes 707, the wastewater flows into the lower heat exchange plate 705, is collected by the lower heat exchange plate 705, and is discharged through the drain pipe 706 to the middle area of ​​the corresponding evaporation chamber 201, avoiding mixing with unheated wastewater and ensuring a stable concentration gradient.

[0023] When the waste liquid flows inside the heat exchange tube 707, the flowing waste liquid impacts the spiral disturbance component 9 simultaneously. As the waste liquid flows inside the heat exchange tube 707, the spiral blades 904 create a spiral pulsating flow. The centrifugal force and pulsation of the spiral flow generate a disturbance effect. The spiral flow prolongs the residence time of the waste liquid inside the heat exchange tube 707, increasing the contact area between the waste liquid and the wall of the heat exchange tube 707. The pulsating effect breaks down the boundary layer on the inner surface of the heat exchange tube 707, preventing excessive local temperature gradients, making the waste liquid heat-dissipated more evenly, reducing heat exchange dead zones, and significantly improving the heat exchange rate. This is suitable for MVR equipment. The energy-saving requirements of closed-loop steam; the pulsating impact of the shear force generated by the spiral pulsating flow can flush away scale particles (such as crystalline particles precipitated during wastewater concentration) on the inner wall of the heat exchange tube 707 and the waste liquid flow path, preventing scale from adhering to the surface of the heat exchange component 7, avoiding blockage of the heat exchange tube 707 which would lead to decreased heat exchange efficiency and increased equipment energy consumption, while reducing the cleaning frequency of the heat exchange component 7 and extending the service life of the equipment; for high-viscosity, high-concentration concentrated waste liquid, the spiral pulsating flow can enhance the turbulence of the waste liquid, avoiding stratification and stagnation due to high viscosity. This ensures sufficient contact between the waste liquid and the heat exchange medium, guaranteeing the concentration effect while reducing the operating load of the circulating pump, further improving the stability and energy efficiency of the equipment. Simultaneously, the secondary circulation pump 604 allows for frequent adjustment of the flow rate of the pumped wastewater. Wastewater with varying flow rates impacts the spiral agitation component 9 inside the heat exchange tube 707, generating varying degrees of impact on the spiral blades 904. This causes the spiral blades 904 to spring on the fixed shaft 901 via the connecting shaft 903 and spring 902. The spiral blades 904 can scrape the inner wall of the heat exchange tube 707 with their edges, thereby cleaning the scale inside the heat exchange tube 707 and further improving heat exchange efficiency. It should be noted that the spring 902 is a high-temperature and high-pressure resistant wave spring, and a high-temperature resistant protective sleeve can be fitted over the spring 902 according to usage requirements to prevent waste liquid from corroding the spring 902 and extend its service life. A limiting sleeve can be added to the bottom of the fixed shaft 901 according to usage requirements to limit the connecting shaft 903 and prevent the spiral blades 904 from lateral movement. The offset ensures that the clearance between the spiral blade 904 and the inner wall of the heat exchange tube 707 is controlled within 0.5-1mm; the flow rate regulation of the secondary circulation pump 604 adopts "variable frequency graded regulation", with 3-5 preset flow rates. According to the scaling condition of the inner wall of the heat exchange tube 707 (feedback through temperature sensor 10), the flow rate is automatically adjusted to make the spiral blade 904 produce uniform bouncing scraping, avoiding component damage caused by uneven force; the spiral blade 904 is made of wear-resistant and corrosion-resistant titanium alloy material, and the edges are rounded to reduce wear on the inner wall of the heat exchange tube 707; Simultaneously, the main circulation pump 601 starts, drawing concentrated wastewater from the bottommost evaporation chamber 201 (where the vacuum level and concentration are highest) through the main circulation suction pipe 602. This wastewater is then transported to the top of the topmost evaporation chamber 201 via the main circulation discharge pipe 603, achieving wastewater circulation among the three evaporation chambers 201. Simultaneously, the control valve 204 on the connecting pipe 203 of the partition plate 202 automatically adjusts its opening according to the liquid level and concentration changes in each evaporation chamber 201, allowing the wastewater to flow from top to bottom in stages, forming a gradient concentration where the concentration is lowest in the topmost evaporation chamber 201 and highest in the bottommost chamber, ensuring the wastewater is gradually concentrated to the required concentration. The lower heat exchange plate 705 inside the heat exchange shell 701 is connected to the upper heat exchange plate 702 via a heat exchange pipe 707, ensuring uniform distribution of the heating medium. The drain pipe 706 in the middle of the lower heat exchange plate 705 allows for timely discharge of the fully heat-exchanged wastewater into the bottom of the evaporation chamber 201.

[0024] Specifically, such as Figures 1-4 , Figure 8 and Figure 9As shown, a vacuum assembly 4 is provided on the outside of the evaporation cylinder 2. The vacuum assembly 4 includes a vacuum pump 401 fixedly mounted on the equipment rack 1. One end of the vacuum pump 401 is fixedly connected to a buffer tank 402, and one end of the buffer tank 402 is fixedly connected to a vacuum manifold 403. Three vacuum manifolds 404 are fixedly connected to the vacuum manifold 403, and each of the three vacuum manifolds 404 is equipped with a vacuum regulating valve. The ends of the three vacuum manifolds 404 are interconnected with the interior of the evaporation chamber 201. A vapor compression assembly 5 is provided at the upper end of the equipment rack 1. The vapor compression assembly 5 includes components fixedly mounted on the equipment rack 1. An MVR steam compressor 501 is located on one side. The input end of the MVR steam compressor 501 is fixedly connected to a steam collection manifold 504. The input end of the steam collection manifold 504 is fixedly connected to three steam collection manifolds 505. The input ends of the steam collection manifolds 505 extend into the interior of the evaporation chamber 201. A demisting module 8 is fixedly installed at the input end of each steam collection manifold 505. The output end of the MVR steam compressor 501 is connected to a steam buffer tank 502. The output end of the steam buffer tank 502 is connected to a condenser 503 and a steam discharge manifold 506. The output end of the steam discharge manifold 506 is connected to... Three steam discharge manifolds 507 are provided, with their ends penetrating the outer wall of the evaporator cylinder 2 and communicating with the interior of the heat exchange shell 701. A multi-stage conical crystallizer 13 is connected to the bottom of the evaporator cylinder 2, and a cyclone centrifugal mechanism 14 is connected to the bottom of the multi-stage conical crystallizer 13. It should be noted that in actual operation, a high-pressure safety valve (with a preset pressure threshold adapted to the equipment's operating pressure, automatically releasing pressure if the threshold is exceeded) and a temperature sensor and a pressure sensor need to be installed at the exhaust port of the MVR steam compressor 501 and the top of the steam buffer tank 502, respectively. When the exhaust temperature or the pressure in the steam buffer tank 502 exceeds the preset value, [the valve will automatically release pressure]. The sensor feeds back signals to the control system, automatically reducing the MVR compressor speed or opening the condenser 503 to increase the amount of excess steam handled, thus achieving overload protection. A pneumatic regulating valve is installed between the condenser 503 and the steam buffer tank 502, which is linked to the pressure sensor of the steam buffer tank 502. When the pressure of the steam buffer tank 502 is higher than the preset value, the pneumatic regulating valve automatically opens to adjust the amount of excess steam entering. A condensate drain pipe is added to the bottom of the condenser 503, which is connected to the condensate collection tank. A drain valve is installed on the drain pipe to automatically drain the condensate, preventing condensate accumulation from affecting the condensation effect. At the same time, the recovered condensate can be recycled as equipment makeup water.

[0025] By adopting the above technical solution, during use, the vacuum assembly 4 is activated, and the vacuum pump 401 starts working. After being buffered and stabilized by the buffer tank 402, the pressure is distributed to three vacuum manifolds 404 through the vacuum main pipe 403, which respectively evaporate the three evaporation chambers 201. The vacuum sensor 12 monitors the vacuum level inside each evaporation chamber 201 in real time and feeds back the signal to the vacuum pump 401 and the control system. By adjusting the power of the vacuum pump 401 and the control valves of the solenoid valves distributed on each vacuum manifold 404, a reasonable vacuum gradient is formed in the three evaporation chambers 201 (to meet the needs of staged evaporation), while maintaining the vacuum level of each evaporation chamber 201 is stable, reducing the wastewater evaporation temperature and achieving energy-saving evaporation. The buffer tank 402 can avoid vacuum pressure fluctuations, protect the vacuum pump 401, and extend the service life. Its service life; it should be noted that a small demisting filter (with the same structure as the demisting module 8 of the vapor collection manifold 505, using stainless steel wire mesh + polytetrafluoroethylene coating) is added between the vacuum regulating valve and the evaporation chamber 201 on each vacuum manifold 404 to intercept waste liquid droplets and crystal particles, preventing impurities from entering the vacuum pump 401; the vacuum regulating valve is linked with the vacuum degree sensor 12, and the valve opening is precisely adjusted by the control system. Combined with the frequency conversion control of the vacuum pump 401, the vacuum degree of each evaporation chamber 201 is precisely controlled to ensure the stability of the vacuum gradient; according to actual operation requirements, a check valve is added between the buffer tank 402 and the vacuum pump 401 to prevent the gas in the buffer tank 402 from being drawn back into the evaporation chamber 201 when the vacuum pump 401 stops, thus disrupting the vacuum environment.

[0026] During the initial startup of the equipment, the heat exchange medium inside the heat exchange assembly 7 can be preheated by connecting to an external auxiliary heat source through the initial valve pipe connected to the heat exchange assembly 7, or the steam generated during the initial startup of the MVR steam compressor 501 can be directly introduced into the heat exchange shell 701 to provide an initial heat source for wastewater evaporation. When the heat exchange assembly 7 is operating, the high-temperature steam inside the heat exchange shell 701 flows through the connecting holes 704 in the three sets of fixed baffles 703, thereby heating the waste liquid inside the heat exchange tubes 707 that penetrate the fixed baffles 703. After absorbing heat, the wastewater... Boiling and evaporating in the vacuum environment of the evaporation chamber 201 generates secondary steam (low-grade steam), completing the initial concentration of wastewater. The secondary steam generated in each evaporation chamber 201 is collected through the steam collection manifold 505. The demister module 8 installed at the input end of the steam collection manifold 505 can completely remove the liquid droplets entrained in the secondary steam, preventing droplets from entering the MVR steam compressor 501 and causing component wear and corrosion. It should be noted that the demister module 8 is existing technology and will not be described in detail here. The purified secondary steam is collected through the steam collection main pipe 504. The steam enters the input terminal of the MVR steam compressor 501; the MVR steam compressor 501 starts, pressurizing and heating the low-grade secondary steam into high-grade, high-temperature, and high-pressure steam, thereby improving the heat exchange capacity of the steam; the compressed steam enters the steam buffer tank 502 to achieve stable buffering of steam pressure and flow, avoiding the impact of steam parameter fluctuations on subsequent heat exchange effects; a portion of the high-temperature and high-pressure steam output from the steam buffer tank 502 enters the condenser 503 to balance excess steam in the system (when the steam volume exceeds the heat exchange demand), and the condensed liquid can be recycled; Another portion is diverted through the steam discharge main pipe 506 to three steam discharge manifolds 507, which pass through the outer wall of the evaporator cylinder 2 and enter the heat exchange shell 701 of each evaporator chamber 201, providing a continuous heating source for the heat exchange tubes 707. After heat exchange is completed, the steam condenses into liquid and can be discharged and recovered through the liquid drainage structure of the heat exchange component 7, realizing the closed-loop recycling of steam and significantly reducing energy consumption. It should be noted that all valve bodies are selected as corrosion-resistant and high-temperature resistant electric regulating type, which is linked with the PLC control system to realize full-process automatic control and reduce manual intervention.

[0027] Working principle: Before starting the equipment, complete basic debugging and media preparation: check the sealing of each component connection (evaporation chamber 201, heat exchange component 7, pipe flanges, etc.) to ensure no leakage; complete the initial parameter calibration through liquid level sensor 11, temperature sensor 10, vacuum sensor 12, and concentration sensor 205 to ensure accurate monitoring; check that each valve body, pump body (transfer pump 302, main circulation pump 601, secondary circulation pump 604, etc.), MVR vapor compressor 501, and vacuum pump 401 are in normal standby state; prepare the multi-stage conical crystallizer 13 and cyclone centrifuge mechanism 14 to receive concentrate and crystallize; During wastewater feeding and initial liquid distribution, the wastewater conveying assembly 3 is activated. The conveying pump 302 draws the wastewater to be treated through the conveying pipe 301 and distributes it through the wastewater conveying main pipe 303 to three wastewater conveying manifolds 304, which respectively convey the wastewater to the three vertically distributed evaporation chambers 201 in the evaporation cylinder 2, achieving synchronous feeding of the three evaporation chambers 201. After the wastewater enters each evaporation chamber 201, the liquid level sensor 11 monitors the liquid level in real time. When the liquid level reaches the preset value, a feedback signal is sent to the control system to adjust the speed of the conveying pump 302 or shut it down to stop feeding, ensuring that the initial liquid level of each evaporation chamber 201 is consistent, laying the foundation for subsequent staged evaporation and liquid seal formation. The partition plate 202 adopts a conical surface design to facilitate the convergence of liquid. The control valve 204 on the connecting pipe 203 in the middle position is in the initial adjustment state, preparing for the subsequent staged flow of wastewater. At the same time, the flow rate of liquid between stages is initially controlled by the preset opening degree of the control valve 204. The vacuum pump assembly 4 is activated, and the vacuum pump 401 begins operation. After being buffered and stabilized by the buffer tank 402, the vacuum pump is distributed to three vacuum manifolds 404 via the vacuum main pipe 403, which then evacuate the three evaporation chambers 201 respectively. The vacuum sensor 12 monitors the vacuum level inside each evaporation chamber 201 in real time and sends the feedback signal to the vacuum pump 401 and the control system. By adjusting the power of the vacuum pump 401 and the control valves of the solenoid valves distributed on each vacuum manifold 404, a reasonable vacuum gradient is formed in the three evaporation chambers 201, while maintaining a stable vacuum level in each evaporation chamber 201, reducing the wastewater evaporation temperature, and achieving energy-saving evaporation. The buffer tank 402 helps to avoid vacuum pressure fluctuations, protects the vacuum pump 401, and extends its service life. During initial startup, the heat exchange medium within the heat exchange assembly 7 can be preheated by connecting to an external auxiliary heat source via an initial valve pipe connected to the heat exchange assembly 7. Alternatively, steam generated during the initial startup of the MVR steam compressor 501 can be directly introduced into the heat exchange shell 701 to provide an initial heat source for wastewater evaporation. As the heat exchange assembly 7 operates, the high-temperature steam within the heat exchange shell 701 flows through the connecting holes 704 within three sets of fixed baffles 703, thereby heating the waste liquid inside the heat exchange tubes 707 that penetrate the fixed baffles 703. After absorbing heat, the wastewater boils and evaporates in the vacuum environment of the evaporation chamber 201, generating secondary steam and completing the initial concentration of the wastewater. The secondary steam generated in each evaporation chamber 201 is collected through a steam collection manifold 505. The demisting module 8 installed at the input end of the steam collection manifold 505 thoroughly removes liquid droplets entrained in the secondary steam, preventing droplets from entering the MVR steam compressor 501 and causing component wear and corrosion. It should be noted that the demisting module 8 is existing technology. Without going into detail here, the purified secondary steam is collected through the steam collection manifold 504 and enters the input end of the MVR steam compressor 501. The MVR steam compressor 501 starts up, pressurizes and heats the low-grade secondary steam, and upgrades it into high-grade, high-temperature and high-pressure steam, thereby improving the heat exchange capacity of the steam. The compressed steam enters the steam buffer tank 502 to achieve stable buffering of steam pressure and flow, and avoids the impact of steam parameter fluctuations on the subsequent heat exchange effect. Part of the high-temperature and high-pressure steam output from the steam buffer tank 502 enters the condenser 503 to balance the excess steam in the system, and the condensed liquid can be recycled. The other part is distributed through the steam discharge manifold 506 to three steam discharge manifolds 507, which pass through the outer wall of the evaporator 2 and enter the heat exchange shell 701 of each evaporator chamber 201, providing a continuous heating source for the heat exchange tubes 707. After completing the heat exchange, the steam condenses into liquid and can be discharged through the non-condensable liquid discharge port 708 of the heat exchange component 7, realizing the closed-loop recycling of steam and significantly reducing energy consumption. When heat exchange is performed on the wastewater inside the equipment, three secondary circulation pumps 604 start simultaneously, drawing wastewater from the corresponding evaporation chamber 201 through the secondary circulation suction pipe 606. It should be noted that the secondary circulation suction pipe 606 extends to the lower middle part of the corresponding evaporation chamber 201, and is then transported through the secondary circulation discharge pipe 605 to the upper heat exchange plate 702 inside the heat exchange shell 701. The upper heat exchange plate 702 ensures that the wastewater is evenly distributed into each heat exchange tube 707, allowing for thorough heat exchange with the high-temperature steam outside the heat exchange tubes 707. Three sets of fixed baffles 703 and connecting holes 704 inside the heat exchange shell 701 are used to change the flow of the heat exchange shell. The hot steam flows inside the body 701 and outside the heat exchange tube 707. The connecting holes 704 are opened in half of each fixed baffle 703. The connecting holes 704 on adjacent fixed baffles 703 are obliquely symmetrically distributed, so that the hot steam flows in an S-shape, prolonging the residence time of the steam in the heat exchange shell 701 and improving the heat exchange efficiency between the hot steam and the heat exchange tube 707. After the waste liquid completes heat exchange inside the heat exchange tube 707, it flows into the lower heat exchange plate 705. After being collected by the lower heat exchange plate 705, it is discharged through the drain pipe 706 to the middle area of ​​the corresponding evaporation chamber 201 to avoid mixing with the unheated waste liquid and ensure the stability of the concentration gradient.

[0028] When the waste liquid flows inside the heat exchange tube 707, the flowing waste liquid impacts the spiral disturbance component 9 simultaneously. As the waste liquid flows inside the heat exchange tube 707, it forms a spiral pulsating flow through the spiral blades 904. Simultaneously, the secondary circulation pump 604 can frequently adjust the flow rate of the pumped wastewater. Wastewater with varying flow rates impacts the spiral disturbance component 9 inside the heat exchange tube 707, generating varying degrees of impact on the spiral blades 904. This allows the spiral blades 904 to continuously... The connecting shaft 903 and spring 902 bounce on the fixed shaft 901, which allows the edge of the spiral blade 904 to scrape the inner wall of the heat exchange tube 707, thereby cleaning the scale generated inside the heat exchange tube 707 and further improving the heat exchange efficiency. At the same time, the main circulation pump 601 starts, and the concentrated wastewater in the bottom evaporation chamber 201 is drawn through the main circulation suction pipe 602 and transported to the top of the top evaporation chamber 201 through the main circulation discharge pipe 603, realizing the circulation of wastewater between the three evaporation chambers 201. Meanwhile, the control valve 204 of the connecting pipe 203 on the partition plate 202 automatically adjusts its opening according to the changes in liquid level and concentration in each evaporation chamber 201, so that the wastewater flows from top to bottom in stages, forming a stepped concentration gradient to ensure that the wastewater is gradually concentrated to the standard concentration; the lower heat exchange plate 705 in the heat exchange shell 701 is connected to the upper heat exchange plate 702 through the heat exchange pipe 707 to ensure uniform distribution of the heating medium; the drain pipe 706 in the middle of the lower heat exchange plate 705 can promptly discharge the fully heat-exchanged waste liquid into the bottom of the evaporation chamber 201, where the bottommost evaporator... After being concentrated in stages, the wastewater in chamber 201 reaches a saturated concentration and then enters the multi-stage conical crystallizer 13. The multi-stage conical structure promotes the settling of the liquid, allowing the crystal particles to gradually grow and settle, thus achieving the initial separation of crystals from mother liquor. The liquid at the bottom of the multi-stage conical crystallizer 13 enters the cyclone centrifuge mechanism 14, where the crystal particles are completely separated from the mother liquor through high-speed cyclone centrifugation. The separated crystal particles can be collected and recycled, while the mother liquor can be returned to the evaporation chamber 201 to continue evaporation and concentration, achieving the resource utilization and zero discharge of wastewater. During equipment operation, various sensors monitor operating parameters in real time, forming a closed-loop control system: temperature sensor 10 monitors the wastewater temperature in each evaporation chamber 201, feeding back the signal to the MVR steam compressor 501 to adjust steam compression parameters and ensure stable heat exchange temperature; liquid level sensor 11 monitors the liquid level in each evaporation chamber 201, coordinating with the transfer pump 302, main circulation pump 601, and control valve 204 to maintain stable liquid level; vacuum sensor 12 monitors the vacuum level in each evaporation chamber 201, coordinating with the vacuum pump 401 to ensure stable vacuum gradient. All control actions are automatically completed by the control system, achieving continuous, stable, and efficient operation of the equipment.

[0029] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An energy-saving continuous evaporation crystallization device for wastewater, comprising a frame (1) and an evaporation cylinder (2) fixedly installed inside the frame (1), characterized in that, Also includes: The evaporator (2) has three vertically distributed evaporation chambers (201) inside. Each evaporation chamber (201) is equipped with a heat exchange assembly (7) for heating wastewater. The heat exchange assembly (7) includes a heat exchange shell (701) fixedly installed inside the evaporation chamber (201). An upper heat exchange plate (702) is fixedly installed on the upper side inside the heat exchange shell (701). Multiple heat exchange tubes (707) are inserted and connected inside the bottom end of the upper heat exchange plate (702). The heat exchange tube (707) is equipped with a spiral disturbance component (9). The spiral disturbance component (9) includes a fixed shaft (901) fixedly installed inside the upper end of the heat exchange tube (707). A spring (902) is fixedly installed in the middle position of the fixed shaft (901). A connecting shaft (903) is fixedly installed at the bottom end of the spring (902). A spiral blade (904) is fixedly installed on the outside of the connecting shaft (903). A wastewater circulation component (6) is provided both inside and outside the evaporator (2).

2. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 1, characterized in that: The adjacent evaporation chambers (201) are separated by a partition plate (202). The upper end face of the partition plate (202) is designed as a conical surface. A connecting pipe (203) is fixedly installed in the middle of the two upper partition plates (202). A control valve (204) is installed on the wall of the connecting pipe (203). A concentrated liquid standard detection valve pipe (206) is installed on the bottom partition plate (202). A concentration sensor (205) is embedded in the upper end face of the partition plate (202).

3. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 2, characterized in that: The outer wall of the evaporator (2) is provided with a waste liquid conveying assembly (3). The waste liquid conveying assembly (3) includes a conveying pump (302) fixed on the outer wall of the evaporator (2). The input end of the conveying pump (302) is fixedly connected to a conveying pipe (301). The output end of the conveying pump (302) is fixedly connected to a wastewater conveying main pipe (303). The output end of the wastewater conveying main pipe (303) is fixedly connected to multiple wastewater conveying manifolds (304). The output end of the wastewater conveying manifolds (304) is interconnected with the interior of the evaporation chamber (201).

4. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 3, characterized in that: A vacuum assembly (4) is provided on the outside of the evaporation cylinder (2). The vacuum assembly (4) includes a vacuum pump (401) fixedly installed on the equipment frame (1). One end of the vacuum pump (401) is fixedly connected to a buffer tank (402). One end of the buffer tank (402) is fixedly connected to a vacuum manifold (403). Three vacuum manifolds (404) are fixedly connected to the vacuum manifold (403). The ends of the three vacuum manifolds (404) are connected to the interior of the evaporation chamber (201).

5. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 1, characterized in that: A vapor compression assembly (5) is provided at the upper end of the equipment rack (1). The vapor compression assembly (5) includes an MVR vapor compressor (501) fixedly installed on one side of the equipment rack (1). The input end of the MVR vapor compressor (501) is fixedly connected to a vapor collection manifold (504). The input end of the vapor collection manifold (504) is fixedly connected to three vapor collection manifolds (505). The input end of the vapor collection manifolds (505) extends into the interior of the evaporation chamber (201). A demisting module (8) is fixedly installed at the input end of the vapor collection manifolds (505).

6. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 5, characterized in that: The output end of the MVR steam compressor (501) is connected to a steam buffer tank (502), the output end of the steam buffer tank (502) is connected to a condenser (503) and a steam discharge manifold (506), the output end of the steam discharge manifold (506) is connected to three steam discharge manifolds (507), and the end of the steam discharge manifold (507) penetrates the outer wall of the evaporator (2) and communicates with the interior of the heat exchange shell (701).

7. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 1, characterized in that: The wastewater circulation assembly (6) includes a main circulation pump (601) fixedly installed on the side wall of the evaporator (2). The input end of the main circulation pump (601) is connected to a main circulation suction pipe (602). The input end of the main circulation suction pipe (602) passes through the evaporator (2) and is connected to the bottom end of the bottommost evaporation chamber (201). The output end of the main circulation pump (601) is connected to a main circulation discharge pipe (603). The end of the main circulation discharge pipe (603) passes through the evaporator (2) and is connected to the top end of the topmost evaporation chamber (201).

8. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 7, characterized in that: The wastewater circulation assembly (6) also includes three secondary circulation pumps (604) fixedly installed on the side wall of the evaporator (2). The output end of the secondary circulation pump (604) is connected to a secondary circulation discharge pipe (605). The output end of the secondary circulation discharge pipe (605) passes through the evaporator (2), the heat exchange shell (701) and the upper heat exchange plate (702) and communicates with each other. The input end of the secondary circulation pump (604) is connected to a secondary circulation suction pipe (606).

9. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 1, characterized in that: The heat exchange tube (707) is designed with a large diameter. The diameter of the heat exchange tube (707) in each heat exchange assembly (7) decreases step by step from top to bottom. A lower heat exchange plate (705) is fixedly installed on the lower side of the heat exchange shell (701). The lower heat exchange plate (705) and the upper heat exchange plate (702) are interconnected by several heat exchange tubes (707). A drain pipe (706) that penetrates the bottom end face of the heat exchange shell (701) is fixedly connected to the middle position of the lower heat exchange plate (705). A non-condensable liquid discharge port (708) is fixedly connected to the bottom end of the heat exchange shell (701). Three sets of parallel fixed baffles (703) are fixedly installed inside the heat exchange shell (701). A connecting hole (704) is opened inside the fixed baffles (703).

10. The energy-saving wastewater continuous evaporation crystallization equipment according to claim 1, characterized in that: The inner wall of the evaporator (2) is fitted with three sets of temperature sensors (10), liquid level sensors (11), and vacuum sensors (12) corresponding to the evaporation chamber (201). The bottom end of the evaporator (2) is connected to a multi-stage conical crystallizer (13), and the bottom end of the multi-stage conical crystallizer (13) is connected to a swirling centrifugal mechanism (14).

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