Complex solution evaporator

Abstract

The present application relates to a kind of complex solution evaporator, by shell, heat exchange component, transmission component, bearing seal component, frame support component, auxiliary discharge component, defoaming component, pipeline component and control component composition.Shell includes shell and left and right two side end plate, the middle part area of shell height direction installs heat exchange component, and heat exchange component is by multiple side-by-side heat exchange plate group composition.Shell upper area is gas-liquid separation zone, installs defoaming component.Shell lower area is salt precipitation zone, installs auxiliary discharge component.Shell top is provided with secondary steam outlet and feed inlet, and shell bottom is provided with condensate outlet and discharge port.Transmission component's stirring shaft traverses heat exchange plate group middle part, and multiple scrapers are fixed on stirring shaft.Pipeline component includes steam inlet pipe group and condensate pipe group;Steam inlet pipe group is connected with the plate group medium interface above heat exchange plate group, and condensate pipe group is connected with the plate group medium interface below heat exchange plate group.

Description

Technical Field

[0001] This invention relates to the field of evaporation and concentration equipment technology, specifically to an evaporator suitable for complex solutions with characteristics such as high viscosity, high salt, high COD, easy foaming, and easy scaling. Background Technology

[0002] In the fields of chemical engineering, environmental protection, and pharmaceuticals, there are numerous complex solutions characterized by high viscosity, high salinity, high COD, easy foaming, and easy scaling, such as landfill leachate, MVR mother liquor, multi-effect evaporation residue, membrane concentrate, and bio-fermentation broth. These solutions have complex compositions, high mineralization, and high levels of high-boiling organic matter, making them prone to problems such as viscosity surges, boiling point elevations, crystallization, salt precipitation, and scale deposition during evaporation and concentration, posing significant challenges to deep concentration treatment. Patent application CN202010854682.8 discloses a "deep concentration evaporator for high-salt, high-viscosity, and easily scaling solutions," but it suffers from numerous key defects in engineering applications, severely limiting its treatment efficiency and operational stability, and failing to meet the requirements for efficient and stable treatment of complex solutions. The main problems include: 1) The upper area of ​​the heat exchange plates cannot be effectively covered by the scraper, resulting in the heat exchange area not being fully utilized, affecting the heat transfer efficiency of the evaporator. In areas not covered by the scraper, dirt and salt crystals easily accumulate during evaporation. After long-term operation, bridging occurs between the upper plates of the evaporator, blocking the flow channels between the heat exchange plates and severely affecting the normal operation of the evaporator. 2) The steam inlet pipelines of each heat exchange plate are connected in series. When a heat exchange plate malfunctions (such as blockage or leakage), the entire steam inlet assembly of the evaporator will fail, and all heat exchange plates will be unable to work properly, resulting in low assembly reliability. 3) There is no gas-liquid separation zone at the top of the evaporator, leading to severe entrainment of secondary steam mist, causing the steam condensate to fail to meet emission standards. 4) The high-viscosity, high-salt concentrate deposited at the bottom of the evaporator clumps together and cannot be discharged smoothly. Salt accumulates between the heat exchange plates and is constantly agitated by the scraper, causing severe wear on the heat exchange plates. This also exacerbates the mechanical breakage of the salt crystals, resulting in excessively small salt particles, affecting the quality of the discharged salt and the efficiency of solid-liquid separation. 5) Solid particles such as salt in complex solutions cause severe wear on the agitator shaft seal. Seal failure leads to frequent material leakage from the evaporator shaft seal, affecting the stable operation of the evaporator. Summary of the Invention

[0003] The present invention aims to provide a complex solution evaporator to overcome the shortcomings of the prior art. The technical problem to be solved by the present invention is achieved through the following technical solution.

[0004] A complex solution evaporator includes a shell, a heat exchange assembly, a transmission assembly, a bearing sealing assembly, a frame support assembly, an auxiliary discharge assembly, a demister assembly, a piping assembly, and a control assembly.

[0005] The outer shell includes a shell and left and right end plates. The heat exchange assembly is installed in the middle area of ​​the shell in the height direction. The heat exchange assembly is composed of multiple heat exchange plates arranged side by side.

[0006] The upper part of the shell is the gas-liquid separation zone, where the demister assembly is installed; the lower part of the shell is the salt settling zone, where the auxiliary discharge assembly is installed.

[0007] The top of the shell is provided with a secondary steam outlet and a feed inlet, and the bottom of the shell is provided with a condensate outlet and a discharge outlet;

[0008] The transmission assembly consists of a first motor, a reducer and a stirring shaft. The stirring shaft runs through the middle of the heat exchange plate group. Multiple scrapers are fixed on the stirring shaft at equal intervals, and each scraper is inserted into the gap between the heat exchange plate group.

[0009] The bearing sealing assembly includes a first bearing seal for sealing the stirring shaft, which passes through the left and right shells of the outer casing via the first bearing seal.

[0010] The piping assembly includes a steam inlet pipe assembly and a condensate pipe assembly; the steam inlet pipe assembly is connected to the plate medium interface above the heat exchange plate assembly, and the condensate pipe assembly is connected to the plate medium interface below the heat exchange plate assembly.

[0011] Preferably, the auxiliary discharge assembly includes a second motor, a spiral discharger, and a second bearing seal; the spiral discharger is a spiral ribbon structure, installed in the salt settling zone at the bottom of the housing, and driven by the second motor; the bearing seal assembly further includes a second bearing seal for sealing the rotating shaft of the spiral discharger, and the rotating shaft passes through the left and right shells of the housing via the second bearing seal.

[0012] Preferably, the auxiliary discharge assembly includes a circulating pump and a circulating discharge pipe assembly. A reflux port is provided at the lower part of both end plates. The circulating discharge pipe assembly connects the discharge port at the bottom of the evaporator shell to the inlet of the circulating pump. The outlet of the circulating pump is connected to the reflux port at the bottom of the end plate, and a discharge port is opened on the reflux pipeline.

[0013] Preferably, the frame support assembly includes a core frame, a core support, an equipment support, and a base; the core frame is disposed below the heat exchange plate assembly for positioning and fixing the heat exchange plate assembly; the core support is welded to the inner wall of the shell for supporting and fixing the core frame on which the heat exchange plate assembly is placed; the equipment support is a saddle, fixedly installed on the lower part of the evaporator shell; the base is a steel structure frame for providing overall support and positioning reference.

[0014] Preferably, the shell is a horizontal elliptical cylindrical structure, with the height of the gas-liquid separation zone at the top of the shell being 1 / 4 to 1 / 3 of the shell height, and the height of the salt settling zone at the bottom of the shell being 1 / 4 to 1 / 3 of the shell height; the end plate is sealed to the shell via a flange.

[0015] Preferably, the shell and end plate are provided with reinforcing ribs on the outside, and a manhole is opened on one side of the end plate. The shell is made of carbon steel-stainless steel composite plate, carbon steel-titanium composite plate or carbon steel-duplex steel composite plate.

[0016] Preferably, the heat exchange plate assembly consists of multiple parallel and equally spaced heat exchange plates, a first plate box, and a second plate box. The heat exchange plate is a hollow thin-plate structure of an equilateral triangle. The center of the hypotenuse of the heat exchange plate is provided with a right-angled or circular clearance notch adapted to the stirring shaft. The first plate box and the second plate box are respectively located at the upper and lower vertices of the hypotenuse of the heat exchange plate, and the first plate box and the second plate box are connected to the interior of each heat exchange plate. A first interface is vertically opened on the hypotenuse of the first plate box, and a plate group medium interface is vertically opened on the upper right-angled side of the first plate box. A second interface is vertically opened on the hypotenuse of the second plate box. Two heat exchange plate assemblies with the same external dimensions are flipped up and down and then connected. The flipping and connecting of the two triangular heat exchange plate assemblies forms a heat exchange plate assembly with a square overall shape and a shaft hole in the middle. The medium interfaces of the two plate assemblies are respectively used to introduce heating steam and discharge steam condensate.

[0017] Preferably, the two triangular heat exchanger plate groups can be connected by flange, threaded, quick-connect, or welding; the heat exchanger plates of the heat exchanger plate group are honeycomb bulging plates or heat exchanger plates with internal flow guiding support ribs, and the heat exchanger plate material is 304, 316L, titanium, 2205 duplex steel or Hastelloy, the heat exchanger plate thickness is 5~10mm, the heat exchanger plate spacing is 30~50mm, and the heat exchanger plate group spacing is 30~50mm.

[0018] Preferably, the scraper has a paddle-type structure, consisting of a shaft seat, blades, and reinforcing ribs; the blades are provided with side blades and triangular guide blades, the shaft seat has a scraper positioning hole, the outer diameter of the scraper's rotation matches the length of the heat exchange plate assembly, and the scraper thickness is not greater than the spacing between the heat exchange plates of the heat exchange plate assembly; each scraper is inserted into the gap between the heat exchange plates of the heat exchange plate assembly, and the scraper spacing is equal to the center distance of the heat exchange plates; the stirring shaft is connected to the first motor and the reducer through a coupling, the first motor drives each scraper to rotate between the gaps of the heat exchange plate assembly through the stirring shaft, and the reducer adjusts the basic speed of the scraper to 50 rpm.

[0019] Preferably, the scraper has a two-blade, three-blade, or multi-blade structure, and the scraper blades are straight blades or curved blades, wherein the curve of the curved blade is a combination of multiple equation lines, and the radial low point of the curve is located at 1 / 2. R ~2 / 3R Within the area, R The scraper covers a radius of 1-50 rpm. The scraper material is the same as the heat exchange plate material or is made of polytetrafluoroethylene, polyamide, polyphenylene sulfide, polyoxymethylene, nitrocellulose or other polymer materials. The axial thickness of the scraper is 30-50 mm, and the thickness of the scraper blade side edge is 3-10 mm.

[0020] Preferably, the bearing seal adopts a two-stage composite sealing method. The bearing seal includes a bearing, a bearing bracket, a mechanical seal, and a stuffing box seal. The first stage of the bearing seal adopts a stuffing box seal, and the second stage of the bearing seal adopts a mechanical seal.

[0021] Preferably, the mechanical seal of the bearing seal is a single-end mechanical seal or a double-end mechanical seal, the sealing surfaces of the dynamic ring and stationary ring of the mechanical seal structure are made of silicon carbide or silicon nitride, the sealing pressure range of the mechanical seal is 0.1-1.0MPa, and the applicable temperature range is -20℃ to 200℃.

[0022] Preferably, the core frame and core support are made of the same material as the heat exchange plate, and the equipment support and base are both made of carbon steel.

[0023] Preferably, the demister assembly is a demister installed on the top of the housing, and the demister is a wire mesh demister or a baffle plate demister.

[0024] The piping assembly also includes a drain valve. The steam inlet pipe group adopts a main-branch pipe structure, with the main pipe of the steam inlet pipe group located outside the evaporator, and each branch pipe connected to the medium interface of the plate group above the heat exchange plate group. The condensate pipe group adopts a branch-main pipe structure, with the main pipe of the condensate pipe group located outside the evaporator, and each branch pipe connected to the medium interface of the plate group below the heat exchange plate group. The outlet of the main pipe of the condensate pipe group is connected to the drain valve.

[0025] Preferably, the main pipe and branch pipes of the steam inlet pipe group are connected by flanges outside the evaporator, and valves are installed on each branch pipe; the branch pipes and main pipe of the condensate pipe group are connected by flanges outside the evaporator, and valves and pipe sight glasses are installed on each branch pipe.

[0026] Preferably, the control components include a controller, a thermometer, a level gauge, a pressure gauge, a flow meter, and a frequency converter. The controller is a PLC controller, and the level gauge is a non-contact radar level gauge. The controller collects evaporator temperature, pressure, and flow signals and controls the motor speed according to parameter changes.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) Significantly improved heat exchange efficiency: By optimizing the structure and installation method of the scraper unit, the scraper rotation trajectory completely covers the effective heat exchange area of ​​the heat exchange plate, the material utilization rate of the heat exchange plate is increased to more than 90%, and the material cost of the heat exchange plate equipment is greatly reduced; by external forced agitation and scraper with guide blade, the liquid has an axial velocity component when rotating circumferentially, and the axial velocity formed by the blade guide blade is conducive to the enhanced heat exchange between the liquid and the heat exchange plate; the Kutta flow, strong shear flow and tail vortex formed by the periodic sweep of the scraper blade promote the efficient and clean operation of the heat exchange plate, the measured heat transfer coefficient of the evaporator is not less than 1800W / (m²·℃), and the evaporation capacity reaches 40~60kg / (m²·h).

[0029] (2) Excellent anti-scaling and anti-bridging effects: The scraper unit fully covers the surface of the heat exchange plate, scraping away the dirt and salt deposits on the surface of the heat exchange plate in real time, which completely solves the problem of easy scaling and bridging on the upper heat exchange plate; the salt precipitation zone allows the salt crystals to settle in time, avoiding their accumulation between the heat exchange plates, reducing the risk of plate wear, and extending the service life of the heat exchange plates; the auxiliary discharge component continuously disturbs the liquid at the bottom of the evaporator, avoiding the problem of difficult discharge caused by the deposition and agglomeration of salt crystals and other solids.

[0030] (3) Optimized gas-liquid separation effect: A gas-liquid separation space and a high-efficiency demister are added to the top of the evaporator shell. The gas-liquid separation space is sufficient, and the content of liquid droplets entrained in the secondary steam is reduced to below 5mg / m³, which greatly improves the quality of steam condensate and reduces scaling and corrosion problems in subsequent equipment.

[0031] (4) The reliability of the components is greatly improved: the heat exchange plates adopt a parallel independent steam inlet and liquid outlet design, and each heat exchange plate is equipped with an independent shut-off valve. When a single heat exchange plate fails, it can be independently shut off for maintenance without affecting the normal operation of other heat exchange plates. The continuous and stable operation capability of the components is significantly improved.

[0032] (5) Significantly improved sealing performance: The two-stage composite sealing technology is adopted. The stuffing box seal used in the first stage seal intercepts solids such as salt particles in the overflow liquid, ensuring the safety of the second stage mechanical seal. The second stage mechanical seal achieves complete blocking of the overflow solution. The two stages of seal work together to achieve zero leakage effect of the evaporator stirring shaft seal.

[0033] (6) Wide range of applications and low operating costs: The equipment is suitable for deep volume reduction treatment of various complex solutions such as high viscosity, high salt, high COD, easy foaming, and easy scaling, without the need for cumbersome pretreatment procedures; the components can be equipped with MVR technology to realize the recovery and utilization of secondary steam, resulting in significant energy-saving effects. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the complex solution evaporator of the present invention;

[0035] Figure 2 A AA view of the complex solution evaporator of the present invention;

[0036] Figure 3 This is a schematic diagram of the heat exchange plate assembly of the present invention;

[0037] Figure 4 This is a side view of the heat exchanger assembly;

[0038] Figure 5 This is a bottom view of the heat exchanger assembly;

[0039] Figure 6 A schematic diagram of the assembly of two heat exchanger assemblies;

[0040] Figure 7 This is a schematic diagram of the scraper structure of the present invention;

[0041] Figure 8 This is a schematic diagram of the scraper's operating principle according to the present invention;

[0042] Figure 9 This is a schematic diagram of the bearing sealing assembly structure of the present invention;

[0043] Figure 10 This is a schematic diagram of the complex solution evaporator in Example 2;

[0044] Figure 11 This is a schematic diagram of the complex solution evaporator in Example 3;

[0045] Figure 12 This is a schematic diagram of the heat exchanger plate assembly for the complex solution evaporator in Example 4.

[0046] Figure 13 This is a schematic diagram of the scraper structure of the complex solution evaporator in Example 4.

[0047] The reference numerals in the attached figures are as follows: 1. First motor; 2. Reducer; 3. First bearing seal; 301. Bearing; 302. Bearing bracket; 303. Mechanical seal; 304. Stuffing gland seal; 4. Stirring shaft; 5. Heat exchange plate assembly; 501. First plate box; 502. Second plate box; 503. Second interface; 504. First interface; 505. Plate assembly medium interface; 6. Scraper; 61. Shaft seat; 62. Reinforcing rib; 63. Blade; 64. Guide blade; 65. Side blade; 7. Shell; 71. Second... 72. Steam outlet, 73. Steam inlet, 74. Feed inlet, 75. Discharge outlet, 76. Condensate outlet, 8. Steam inlet pipe assembly, 9. Demister, 10. End plate, 11. Core frame, 12. Core support, 13. Second bearing seal, 14. Screw conveyor, 15. Equipment support, 16. Condensate pipe assembly, 17. Base, 18. Drain valve, 19. Second motor, 20. Controller, 201. Thermometer, 202. Level gauge, 203. Pressure gauge, 21. Circulating pump, 22. Circulating discharge pipe assembly. Detailed Implementation

[0048] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0049] Example 1:

[0050] This embodiment uses the deep reduction treatment of residual solution in the constant discharge vessel of a multi-effect evaporation system as an example to describe in detail the structure and operation steps of the complex solution evaporator of the present invention. The typical characteristics of this feed solution are high salt, high COD, and high viscosity. The main components of the feed solution are sodium sulfate, sodium chloride, and other miscellaneous salts. The feed concentration is 36%, the feed COD is 180,000 mg / L, and the feed viscosity is approximately 200 cP.

[0051] like Figure 1 , Figure 2 As shown, a complex solution evaporator according to this embodiment includes a shell, a heat exchange assembly, a transmission assembly, a bearing sealing assembly, a frame support assembly, an auxiliary discharge assembly, a defoaming assembly, a piping assembly, and a control assembly.

[0052] The outer shell consists of a shell 7 and left and right end plates 10. The shell adopts a horizontal elliptical cylindrical structure with a width of 1400mm, a height of 3000mm, and a length of 4000mm. The heat exchange component and scraper 6 are installed in the middle area of ​​the shell 7. The upper area of ​​the shell 7 is a gas-liquid separation zone with a height of approximately 1000mm, where the demister component is installed. The lower area of ​​the shell is a salt settling zone with a height of approximately 800mm, where the auxiliary discharge component is installed. The top of the shell 7 is provided with a secondary steam outlet 71 and a feed inlet 73, and the bottom of the shell 7 is provided with a condensate outlet 75 and a discharge outlet 74. The end plates 10 are sealed to the shell 7 via flanges. The shell 7 and the end plates 10 are provided with reinforcing ribs on the outside, and a manhole is provided on one end plate 10.

[0053] like Figures 3-5 As shown, the heat exchange system consists of six parallel heat exchange plate groups 5. Each heat exchange plate group 5 comprises ten parallel heat exchange plates arranged at equal intervals, a first plate box 501, and a second plate box 502. The heat exchange plates are hollow thin-plate structures with equilateral triangular shapes. The length of each right-angled side of the heat exchange plate group 5 is 1000mm. The heat exchange plates are manufactured by hydraulically expanding two 1.5mm thick titanium plates after edge sealing and welding. After expansion, the heat exchange plate thickness is 10mm, the internal flow channel width is 7mm, the plate spacing is 50mm, and the total thickness of a single heat exchange plate group 5 is 550mm. A 150mm long right-angle clearance notch is provided at the center of the inclined side of the heat exchange plate. The first plate box 501 and the second plate box 502 are respectively located at the upper and lower vertices of the inclined side of the heat exchange plate, and the first plate box 501 and the second plate box 502 are connected to the internal flow channels of each heat exchange plate. A first interface 504 is vertically opened on the hypotenuse side of the first board box 501, a board assembly media interface 505 is vertically opened on the right-angle side of the upper part of the first board box 501, and a second interface 503 is vertically opened on the hypotenuse side of the second board box 502. The length of the right-angle side of the first board box 501 and the second board box 502 is 200mm.

[0054] like Figure 6 As shown, the two heat exchanger plate assemblies 5 are flipped over and then joined together. Specifically, the first interface 504 of the first heat exchanger plate assembly 5 is joined to the second interface 503 of the second heat exchanger plate assembly 5 via a flange, and the second interface 503 of the first heat exchanger plate assembly 5 is joined to the first interface 504 of the second heat exchanger plate assembly 5 via a flange. The plate medium interface 505 of the first heat exchanger plate assembly 5 is used to introduce heating steam, and the plate medium interface 505 of the second heat exchanger plate assembly 5 is used to discharge steam condensate. By flipping and joining the two triangular heat exchanger plate assemblies 5, a square heat exchanger plate assembly 5 with a central axial hole is formed. The length and width of the square heat exchanger plate assembly 5 formed by the joining are both 1200 mm, and the length and width of the square axial hole formed in the middle are both 250 mm.

[0055] The transmission assembly consists of a first motor 1, a reducer 2, a first bearing seal 3, and a stirring shaft 4. For example... Figure 7 , Figure 8 As shown, the scraper 6 has a paddle-type structure, consisting of a shaft seat 61, blades 63, and reinforcing ribs 62. The blades 63 are equipped with side blades 65 and triangular guide blades 64. The shaft seat 61 has a scraper positioning hole. The blades 63 are 500mm long, and the rotation trajectory of the scraper 6 completely covers the inscribed circle of the heat exchange plate assembly 5. The axial thickness of the scraper 6 is 45mm. The scrapers 6 are evenly spaced and fixed to the stirring shaft 4, with an adjacent scraper 6 spaced 60mm apart. Each scraper 6 is inserted into the gap between the heat exchange plate assembly 5, and the distance between the sidewall of the scraper 6 and the heat exchange plate is 2.5mm. This embodiment uses a two-blade straight-plate scraper 6, made of polyphenylene sulfide (PPS), and integrally injection molded. The stirring shaft 4 is fixed to the left and right end plates 10 of the outer casing 7 via a first bearing seal 3 and is connected to the first motor 1 and the reducer 2. The first motor 1 drives each scraper 6 to rotate between the plates of the heat exchange plate assembly 5 via the stirring shaft 4. The basic rotational speed of the scrapers is controlled at 50 rpm by the reducer 2. The first motor 1 is a YVP series variable frequency motor with a rated power of 30kW. The stirring shaft 4 has a shaft diameter of 150mm and a length of 4500mm. The stirring shaft 4 is made of 2205 duplex steel.

[0056] The bearing sealing assembly includes a first bearing seal 3 for sealing the stirring shaft 4 and a second bearing seal 13 for sealing the rotating shaft of the screw conveyor 14. Figure 9 As shown, the bearing seal includes a bearing 301, a bearing bracket 302, a mechanical seal 303, and a stuffing box seal 304. The bearing seal employs a two-stage sealing system: a stuffing box seal in the first stage and a mechanical seal in the second stage. The stuffing box seal intercepts solids such as salt particles in complex solutions, thus avoiding wear on the sealing surface of the second-stage mechanical seal. The second-stage mechanical seal completely blocks any overflowing solution. The second-stage mechanical seal is a double-end face mechanical seal. The sealing surfaces of the dynamic and static rings of the mechanical seal structure are made of silicon carbide. The sealing pressure range of the mechanical seal is 0.1~0.5MPa, and the applicable temperature range is below 200℃.

[0057] The frame support assembly includes a core frame 11, a core support 12, an equipment support 15, and a base 17. The core frame 11 is used for positioning and fixing each heat exchanger plate assembly 5. The core frame 11 is made of 100×100mm square steel, and the material is 2205 duplex steel. The core support 12 is welded to the inner wall of the shell 7 and is used to support and fix the core frame 11 of the heat exchanger plate assembly 5. The equipment support 15 is a saddle, fixedly installed at the lower part of the evaporator shell 7. The base 17 is a steel structure frame, made of 200×200mm carbon steel square steel, used to provide overall support and reference surface positioning for the evaporator, motor, and other equipment.

[0058] The auxiliary discharge assembly includes a second bearing seal 13, a spiral discharger 14, and a second motor 19. The spiral discharger 14 has a spiral ribbon structure with a diameter of 400 mm and a length of 4500 mm. It is installed in the salt sedimentation zone at the bottom of the housing 7 and fixed to the two end plates 10 by the second bearing seal 13. The spiral discharger 14 is driven by the second motor 19, which operates in a forward and reverse rotation mode with a timer of 5 min / time to agitate and refresh the high solid content liquid at the bottom of the evaporator and discharge it.

[0059] The demisting component is mainly a demister 9 installed on the top of the housing 7. The demister 9 is an SP type wire mesh demister, and the wire mesh material is titanium wire.

[0060] The piping assembly includes a steam inlet pipe group 8, a condensate pipe group 16, and a steam trap 18. The steam inlet pipe group 8 provides heating steam to each heat exchanger plate group 5. The steam inlet pipe group 8 adopts a main-branch pipe structure, with the main pipe located outside the evaporator and each branch pipe connected to a corresponding plate medium interface 505 above the heat exchanger plate group 5. The condensate pipe group 16 adopts a branch-main pipe structure, with the main pipe located outside the evaporator and each branch pipe connected to a corresponding plate medium interface 505 below the heat exchanger plate group 5. The outlet of the main pipe of the condensate pipe group 16 is connected to the steam trap 18. The main and branch pipes of the steam inlet pipe group 8 are connected by flanges outside the evaporator, and valves are installed on each branch pipe to independently cut off the steam supply to a specific heat exchanger plate group 5. The branch pipes and main pipe of the condensate pipe group 16 are connected to the outside of the evaporator by flanges, and valves and pipe sight glasses are installed on each branch pipe to facilitate observation of the condensate condition and to realize the function of independently cutting off the condensate channel of a certain heat exchange plate group.

[0061] The control components include a controller 20, a thermometer 201, a level gauge 202, and a pressure gauge 203. The controller is a PLC controller, and the level gauge 202 is a non-contact radar level gauge to avoid the adverse effects of complex liquids such as high viscosity and high salinity on inaccurate level detection. The controller collects analog signal parameters such as system temperature, pressure, and level, and controls the speed range of the first motor (1-50 rpm) and the forward / reverse switching frequency of the second motor (5 min / time) based on changes in liquid parameters using intelligent algorithms such as PID and fuzzy-PID.

[0062] The working method of this embodiment is as follows:

[0063] The complex liquid to be processed is introduced into the shell through the feed pipe. The liquid level in the evaporator is detected by a radar level gauge. Feeding stops when the liquid level exceeds the heat exchange plate assembly. The first motor is started, and the first motor drives the scraper to rotate within the gap between the heat exchange plate assembly at a speed of 35 rpm via the stirring shaft. 120°C live steam enters the liquid outside the heating plates of each heat exchange plate assembly through the steam inlet pipe assembly. The liquid evaporates at a temperature of 85°C. The steam condensate is discharged from the evaporator through the condensate pipe assembly. The triangular guide blades of the scraper blades push the liquid towards the heat exchange plates on both sides of the scraper. Under the action of the pressure difference between the liquid before and after the scraper, the liquid flows at high speed behind the blades along the gap between the scraper side blades and the heat exchange plates. The high-speed shear flow formed washes away the dirt and crystals on the surface of the heat exchange plates. The periodic sweeping of the scraper ensures the cleanliness of the heat exchange plates and enhances the heat transfer effect between the heat exchange plate assembly and the liquid. Secondary steam, after gravity settling in the gas-liquid separation zone, enters the demister for thorough separation of entrained mist before being discharged from the evaporator. A second motor drives a screw conveyor to rotate in both directions, ensuring that the mixed salt liquid at the bottom of the evaporator remains in a flowing state and preventing it from settling and agglomerating. When the liquid concentration exceeds 90%, the residual liquid is discharged from the evaporator through the discharge port, and the next batch of feed evaporation begins.

[0064] This embodiment optimizes the scraper unit structure and installation method, ensuring that the scraper rotation trajectory completely covers the effective heat exchange area of ​​the heat exchange plate. This completely solves the scaling and bridging problem in areas without scraper coverage, increasing the heat exchange plate material utilization rate to over 95% and significantly reducing the material cost of the heat exchange plate equipment by approximately 30%. External forced agitation and a scraper with guide blades enhance heat transfer between the heat exchange plate and the feed liquid, ensuring scale-free operation of the heat exchange plate. The measured heat transfer coefficient of the evaporator reaches 2200 W / (m²·℃), the evaporation capacity reaches 50 kg / (m²·h), the feed liquid concentration ratio is 2.5, and the feed liquid volume reduction rate is higher than 50%. The salt settling zone at the bottom of the evaporator allows precipitated salt crystals to settle promptly, preventing accumulation between the heat exchange plates and significantly reducing plate wear. The auxiliary discharge system effectively avoids discharge blockage caused by solid deposits. The demister effectively intercepts the entrainment of secondary steam mist, ensuring that the steam condensate meets the direct discharge standard. The two-stage composite seal completely solves the problems of shaft seal leakage and mechanical seal wear.

[0065] Using the evaporator with the structure described in patent CN202010854682.8 as a comparative example, the heat exchange area is the same as in Example 1, both being 120m². 2 The comparative model adopts a single-channel plate series steam inlet method, and the shaft seal adopts a single-end mechanical seal. There is no salt sedimentation zone, gas-liquid separation zone, wire mesh demister, or auxiliary discharge system. The scraper used is a straight plate four-blade scraper with no guide blade.

[0066] When treating the same mixed salt solution as in Example 1, the measured heat transfer coefficient of the evaporator was only 1300 W / (m²·℃), and the evaporation capacity was 30 kg / (m²·h). After 5 days of operation, obvious scaling and bridging appeared on the upper part of the heat exchange plate, requiring frequent shutdowns for cleaning. The secondary steam entrainment droplet content reached 20 mg / m³, and the secondary steam condensate index did not meet the standards. After 6 months of operation, the wear of the heat exchange plate reached 0.3 mm, and the single-end mechanical seal used for the shaft seal was worn by salt particles, resulting in continuous leakage at the shaft seal.

[0067] The following table compares the relevant technical indicators of the comparative example and Example 1:

[0068] Table 1

[0069]

[0070] As can be seen from the comparison, the complex solution evaporator described in this invention is significantly superior to existing equipment in terms of heat exchange efficiency, anti-scaling performance, gas-liquid separation effect, equipment wear control, system reliability, and operating cost.

[0071] Example 2:

[0072] like Figure 10As shown in the figure, this embodiment describes a complex solution evaporator with dual stirring shafts.

[0073] The dual-shaft complex solution evaporator of this embodiment includes a shell, a heat exchange assembly, a transmission assembly, a bearing sealing assembly, a frame support assembly, an auxiliary discharge assembly, a defoaming assembly, a piping assembly, and a control assembly.

[0074] The difference from Embodiment 1 is that the heat exchange assembly in this embodiment uses two rows of parallel heat exchange plates, along with corresponding scraper and transmission assemblies, bearing sealing assemblies, and piping assemblies. The two heat exchange assemblies share the evaporator shell, frame support assembly, auxiliary discharge assembly, demister assembly, and control assembly. The structure and installation method of the heat exchange plate assembly in this embodiment are the same as in Embodiment 1, and will not be repeated here.

[0075] This embodiment is suitable for applications with large evaporation rates or limited space. The evaporation rate of a single unit can exceed 10 t / h. For the same evaporation rate, the dual-shaft system can effectively reduce the load length of the agitator shaft, thereby reducing the shaft diameter. This helps to reduce the size of the heat exchange plate assembly shaft hole, increase the effective utilization area of ​​the heat exchange plate, and reduce the investment in drive shaft and bearing sealing system equipment.

[0076] Example 3:

[0077] like Figure 11 As shown in the figure, this embodiment describes a complex solution evaporator with an external circulation pump for auxiliary discharge components.

[0078] The complex solution evaporator in this embodiment includes a shell, a heat exchange assembly, a transmission assembly, a bearing sealing assembly, a frame support assembly, an auxiliary discharge assembly, a defoaming assembly, a piping assembly, and a control assembly.

[0079] The difference from Embodiment 1 is that the auxiliary discharge assembly in this embodiment uses a circulating pump for backflushing. Specifically, the auxiliary discharge assembly includes a circulating pump 21 and a circulating discharge pipe assembly 22. The circulating pump is a low-speed, wide-channel slurry pump. Return ports are located at the lower part of the end plates 10 on both sides of the evaporator. The discharge pipe assembly connects the discharge port at the bottom of the evaporator shell to the inlet of the circulating pump. The outlet of the circulating pump is connected to the return port at the bottom of the end plate, and a discharge port is opened on the return pipe. The circulating pump has the dual functions of external circulation of the liquid to prevent sedimentation and blockage, and discharge. The structure and installation method of other components such as the heat exchange plate assembly in this embodiment are the same as in Embodiment 1.

[0080] In this embodiment, the evaporator operates by using a circulating pump to ensure the flow pattern of the high-solids-content liquid at the bottom of the evaporator, preventing the deposition of particles such as salt crystals and ensuring normal material discharge. Compared to Embodiment 1, this embodiment eliminates the need for a second bearing sealing assembly, a spiral feeder, and a second motor, simplifying the evaporator manufacturing process.

[0081] Example 4:

[0082] like Figure 12 , Figure 13 As shown, this embodiment describes a complex solution evaporator using a different structure of heat exchange plate assembly and a curved scraper.

[0083] The complex solution evaporator in this embodiment includes a shell, a heat exchange assembly, a transmission assembly, a bearing sealing assembly, a frame support assembly, an auxiliary discharge assembly, a defoaming assembly, a piping assembly, and a control assembly.

[0084] The difference from Embodiment 1 is that, in this embodiment, the medium interface 505 on the first plate box of the heat exchanger plate assembly 5 is parallel to the hypotenuse of the equilateral triangular heat exchanger plate. A square heat exchanger plate assembly is formed by the joining of two triangular heat exchanger plate assemblies, with its diagonal vertically mounted on the core frame 11. Furthermore, this embodiment uses a curved scraper, with the radial low point of the curve located at 2 / 3 of the length. R place ( R (The radius of the circle covered by the scraper).

[0085] Regarding the installation method of the heat exchange plate assembly, in Embodiment 1, the upper edge line of the heat exchange plate assembly inside the evaporator is a horizontal line, while in this embodiment, the upper edge line of the heat exchange plate assembly is two diagonal lines. This embodiment significantly reduces the accumulation of salt near the liquid surface of the evaporator and the probability of bridging between plates. In addition, the curved scraper helps to gather the solution in the center and around the heat exchange plate assembly to the core heat exchange area of ​​1 / 2R to 2 / 3R of the heat exchange plate assembly, which is beneficial to improving the overall heat exchange performance of the evaporator.

[0086] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0087] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments described in this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0088] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0089] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, component, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or that are inherent to such process, method, product, or apparatus.

[0090] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, such as rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0091] In the detailed description above, reference has been made to the accompanying drawings, which form part of this document. In the drawings, similar symbols typically identify similar parts unless the context otherwise indicates otherwise. The illustrated embodiments described in the detailed specification, drawings, and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A complex solution evaporator, characterized in that: It includes the outer shell, heat exchange components, transmission components, bearing sealing components, frame support components, auxiliary discharge components, demister components, piping components, and control components; The outer shell includes a shell and left and right end plates. The heat exchange assembly is installed in the middle area of ​​the shell in the height direction. The heat exchange assembly is composed of multiple heat exchange plates arranged side by side. The upper part of the shell is the gas-liquid separation zone, where the demister assembly is installed; the lower part of the shell is the salt settling zone, where the auxiliary discharge assembly is installed. The top of the shell is provided with a secondary steam outlet and a feed inlet, and the bottom of the shell is provided with a condensate outlet and a discharge outlet; The transmission assembly consists of a first motor, a reducer and a stirring shaft. The stirring shaft runs through the middle of the heat exchange plate group. Multiple scrapers are fixed on the stirring shaft at equal intervals, and each scraper is inserted into the gap between the heat exchange plate group. The bearing sealing assembly includes a first bearing seal for sealing the stirring shaft, which passes through the left and right shells of the outer casing via the first bearing seal. The piping assembly includes a steam inlet pipe assembly and a condensate pipe assembly; the steam inlet pipe assembly is connected to the plate medium interface above the heat exchange plate assembly, and the condensate pipe assembly is connected to the plate medium interface below the heat exchange plate assembly. The scraper has a paddle-type structure, consisting of a shaft seat, blades, and reinforcing ribs. The blades are equipped with side blades and triangular guide blades. The shaft seat has a scraper positioning hole. The outer diameter of the scraper's rotation matches the length of the heat exchange plate assembly. The scraper thickness is not greater than the spacing between the heat exchange plates in the heat exchange plate assembly. Each scraper is inserted into the gap between the heat exchange plates, and the scraper spacing is equal to the center distance between the heat exchange plates. The stirring shaft is connected to the first motor and the reducer via a coupling. The first motor drives each scraper to rotate between the heat exchange plate assemblies via the stirring shaft. The triangular guide blades of the scraper blades push the liquid towards the heat exchange plates on both sides of the scraper. Under the action of the pressure difference between the liquid and the scraper, the liquid flows at high speed towards the rear of the blades along the gap between the scraper side blades and the heat exchange plates. The high-speed shear flow formed washes and cleans the surface of the heat exchange plates. Through external forced agitation and the scraper with guide blades, the liquid has an axial velocity component while rotating circumferentially. The blade guide blades cause the liquid to generate axial velocity.

2. The complex solution evaporator according to claim 1, characterized in that: The auxiliary discharge assembly includes a second motor and a spiral discharger; the spiral discharger is a spiral ribbon structure, installed in the salt settling zone at the bottom of the shell, and driven by the second motor; the bearing sealing assembly also includes a second bearing seal for sealing the rotating shaft of the spiral discharger, the rotating shaft passing through the left and right shells of the outer shell via the second bearing seal.

3. The complex solution evaporator according to claim 1, characterized in that: The auxiliary discharge assembly includes a circulating pump and a circulating discharge pipe assembly. A reflux port is provided at the lower part of the two end plates. The circulating discharge pipe assembly connects the discharge port at the bottom of the evaporator shell to the inlet of the circulating pump. The outlet of the circulating pump is connected to the reflux port at the bottom of the end plate, and a discharge port is opened on the reflux pipeline.

4. The complex solution evaporator according to claim 1, characterized in that: The frame support assembly includes a core frame, a core support, an equipment support, and a base. The core frame is located below the heat exchange plate assembly and is used to position and fix the heat exchange plate assembly. The core support is welded to the inner wall of the shell and is used to support and fix the core frame on which the heat exchange plate assembly is placed. The equipment support is a saddle and is fixedly installed on the lower part of the evaporator shell. The base is a steel structure frame and is used to provide overall support and positioning reference.

5. The complex solution evaporator according to claim 1, characterized in that: The shell is a horizontal elliptical cylindrical structure. The height of the gas-liquid separation zone at the top of the shell is 1 / 4 to 1 / 3 of the shell height, and the height of the salt settling zone at the bottom of the shell is 1 / 4 to 1 / 3 of the shell height. The end plate is sealed to the shell by a flange.

6. The complex solution evaporator according to claim 1, characterized in that: The shell and end plate are provided with reinforcing ribs on the outside, and a manhole is opened on one side of the end plate. The shell is made of carbon steel-stainless steel composite plate, carbon steel-titanium composite plate or carbon steel-duplex steel composite plate.

7. The complex solution evaporator according to claim 1, characterized in that: The heat exchange plate assembly consists of multiple parallel and equally spaced heat exchange plates, a first plate box, and a second plate box. Each heat exchange plate is a hollow, thin-plate structure of an equilateral triangle. A right-angled or circular clearance notch adapted to the stirring shaft is provided at the center of the hypotenuse of the heat exchange plate. The first plate box and the second plate box are respectively located at the upper and lower vertices of the hypotenuse of the heat exchange plate, and the first and second plate boxes are connected to the interior of each heat exchange plate. A first interface is vertically opened on the hypotenuse of the first plate box, and a plate group medium interface is vertically opened upwards on the upper right-angled side of the first plate box. A second interface is vertically opened on the hypotenuse of the second plate box. Two heat exchange plate assemblies of the same external dimensions are flipped and joined together to form a square heat exchange plate assembly with a central shaft hole. The medium interfaces of the two plate assemblies are used for introducing heating steam and discharging steam condensate, respectively.

8. The complex solution evaporator according to claim 1, characterized in that: The two triangular heat exchanger plate assemblies are connected by flange, threaded, quick-connect or welding; the heat exchanger plates of the heat exchanger plate assembly are honeycomb bulging plates or heat exchanger plates with internal flow guiding support ribs.

9. The complex solution evaporator according to claim 1, characterized in that: The scraper has a two-, three-, or multi-blade structure. The scraper blades are straight or curved blades. The curve of the curved blade is a combination of multiple equation lines, and the radial low point of the curve is located at 1 / 2. R ~2 / 3 R Within the area, R The scraper covers the radius of the circle, and the scraper material is the same as the heat exchange plate material.

10. The complex solution evaporator according to claim 1 or 2, characterized in that: The bearing seal adopts a two-stage composite sealing method. The bearing seal includes a bearing, a bearing bracket, a mechanical seal, and a stuffing box seal. The first stage of the bearing seal adopts a stuffing box seal, and the second stage adopts a mechanical seal.

11. The complex solution evaporator according to claim 10, characterized in that: The mechanical seal of the bearing seal adopts a single-end mechanical seal or a double-end mechanical seal, and the sealing surfaces of the dynamic ring and stationary ring of the mechanical seal structure are made of silicon carbide or silicon nitride.

12. The complex solution evaporator according to claim 4, characterized in that: The core frame and core support are made of the same material as the heat exchange plate, and the equipment support and base are made of carbon steel.

13. The complex solution evaporator according to claim 1, characterized in that: The demister assembly is a demister installed on the top of the housing, and the demister is a wire mesh demister or a baffle plate demister.

14. The complex solution evaporator according to claim 1, characterized in that: The piping assembly also includes a drain valve. The steam inlet pipe group adopts a main-branch pipe structure, with the main pipe of the steam inlet pipe group located outside the evaporator, and each branch pipe connected to the medium interface of the plate group above the heat exchange plate group. The condensate pipe group adopts a branch-main pipe structure, with the main pipe of the condensate pipe group located outside the evaporator, and each branch pipe connected to the medium interface of the plate group below the heat exchange plate group. The outlet of the main pipe of the condensate pipe group is connected to the drain valve.

15. The complex solution evaporator according to claim 14, characterized in that: The main pipe and branch pipes of the steam inlet pipe group are connected by flanges outside the evaporator, and valves are installed on each branch pipe; the branch pipes and main pipe of the condensate pipe group are connected by flanges outside the evaporator, and valves and pipe sight glasses are installed on each branch pipe.

16. The complex solution evaporator according to claim 1, characterized in that: The control components include a controller, a thermometer, a level gauge, a pressure gauge, a flow meter, and a frequency converter. The controller is a PLC controller, and the level gauge is a non-contact radar level gauge. The controller collects the temperature, pressure, and flow signals of the evaporator and controls the motor speed according to the parameter changes.

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