Skid-mounted MVR evaporator

Abstract

The invention discloses a skid-mounted MVR evaporator which comprises a rack, the rack is provided with a separator, the separator is provided with a steam outlet, a circulating pipe and a separating pipe, the circulating pipe is provided with a feeding port, and the separating pipe is fixedly communicated with a settling tank; a discharge pump; a heating outlet of the heater is fixedly communicated with the separation pipe through a tangential pipe, the tangential pipe extends in the horizontal direction perpendicular to the separation pipe, and the inner wall of the tangential pipe is tangent to the inner wall of the separation pipe; a circulating pump; the demister is provided with a feeding hole, a liquid outlet and a steam outlet and is internally provided with a defoaming assembly; and the compressor is communicated between the steam outlet and the heating medium inlet. According to the skid-mounted MVR evaporator, heated feed liquid can spirally and upwards enter the separator along the pipe wall of the separation pipe through the tangential pipe, on one hand, the pipe wall of the separation pipe can be scoured, scaling is prevented, meanwhile, crystals fall into a settling tank, on the other hand, the feed liquid enters the separator at a certain initial speed, uniform mixing of high-temperature feed liquid and low-temperature feed liquid is promoted, and the separation efficiency is improved. Bumping is avoided, and evaporation is more uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of MVR evaporation, and in particular to a skid-mounted MVR evaporator. Background Art

[0002] The skid-mounted MVR (Mechanical Vapor Recompression) evaporator adopts a highly integrated design, and each functional module is pre-installed in a frame, which is convenient for transportation and quick installation. It utilizes the secondary steam generated by the evaporator, compresses it through a compressor, so that the pressure and temperature increase, the heat content increases, and then it is sent to a heater to exchange heat with the liquid to be concentrated, so that the liquid to be concentrated maintains a boiling state, while the heating steam itself condenses into water. In this way, the originally wasted steam is fully utilized, the latent heat is recovered, the thermal efficiency is improved, and the processing cost is reduced. Therefore, the skid-mounted MVR evaporator is widely applicable to processes such as concentration, crystallization, and wastewater treatment in the industrial field, and has the characteristics of high energy efficiency and high degree of automation.

[0003] However, in the existing skid-mounted MVR evaporators, when the liquid enters the separator, the flow rate is slow, and it is easy to crystallize and scale at the feed pipe of the separator. Moreover, the heat distribution inside the separator is uneven. In places where the local temperature is relatively high, violent boiling is likely to occur, which impacts and damages the components inside the evaporator, affects the evaporation uniformity of the liquid, reduces the evaporation efficiency, and during the evaporation process, the generated secondary steam contains some liquid droplets. Although a certain amount of liquid droplets can be separated through a vapor-liquid separation device, the separation effect is low, resulting in a certain amount of remaining liquid droplets in the secondary steam input into the compressor, which affects the normal operation and service life of the compressor.

[0004] Therefore, it is necessary to improve the existing skid-mounted MVR evaporator. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects existing in the prior art, and to provide a skid-mounted MVR evaporator that is not easy to scale, ensures evaporation uniformity and efficiency, avoids damaging internal components, and improves the vapor-liquid separation effect.

[0006] To achieve the above technical effects, the technical solution of the present invention is: a skid-mounted MVR evaporator, including a frame, on which are provided: A separator, having a steam outlet at the top, fixedly connected with a circulation pipe and a separation pipe extending in the vertical direction at the bottom. A feed port is provided on the side wall of the circulation pipe, and the bottom of the separation pipe is fixedly connected with a settling tank; A discharge pump, the input end of which is communicated with the settling tank; A heater, having a heat medium inlet, a heat medium outlet, a heating inlet and a heating outlet, wherein a drain valve is connected to the heat medium outlet, the heating outlet is fixedly communicated with the separation tube through a tangential tube, the tangential tube extends along a horizontal direction perpendicular to the separation tube and the inner wall thereof is tangent to the inner wall of the separation tube; A circulation pump, communicated between the circulation tube and the heating inlet; A demister, having a feed inlet, a liquid outlet and a steam outlet and internally provided with a demisting component; A compressor, communicated between the steam outlet and the heat medium inlet.

[0007] Preferably, in order to improve the scouring effect on the inside of the separation tank, the separation tube includes an enlarged diameter section and an equal diameter section that are connected and coaxial from bottom to top, the equal diameter section is cylindrical, the inner diameter of the enlarged diameter section increases successively from bottom to top and the inner diameter at the top is the same as the inner diameter of the equal diameter section, and the enlarged diameter section is connected to the tangential tube.

[0008] Preferably, in order to increase the flow rate and improve the heating effect on the liquid material passing through the heater, at least two layers of heating tubes distributed vertically and in a serpentine shape are arranged in the heater, and the heating tubes are communicated between the heating inlet and the heating outlet.

[0009] Preferably, in order to recycle the liquid material, the liquid outlet is communicated with the separator through a liquid seal anti-backflow tube.

[0010] Preferably, in order to reduce the equipment height, both the demister and the separator are horizontally arranged and the length directions are parallel.

[0011] Preferably, in order to improve the vapor-liquid separation effect, the demisting component includes a cyclone tube and a wire mesh packing which are distributed in sequence, the axial direction of the cyclone tube is parallel to the axial direction of the demister, a spiral ribbon is arranged on the circumferential inner wall of the cyclone tube to guide the steam mixture to pass through the cyclone tube along a spiral track, and the cyclone tubes are densely arranged at one end of the demister adjacent to the steam outlet.

[0012] Preferably, in order to further improve the vapor-liquid separation effect, there are two spiral ribbons and the thread rotation directions are opposite, and the axial ends of the two spiral ribbons on the axial direction of the cyclone tube are flush with each other on the inner side of the cyclone tube.

[0013] Preferably, in order to further improve the vapor-liquid separation effect, the demisting component includes an outer spray cylinder and an inner spray pipe, the outer spray cylinder, the inner spray pipe and the demister are coaxial, the outer spray cylinder is sleeved outside the inner spray pipe, inner spray holes and outer spray holes are respectively arranged on the circumferential inner wall of the outer spray cylinder and the circumferential outer edge of the inner spray pipe, the inner spray holes and the outer spray holes are both communicated with the feed inlet, and the outer spray cylinder and the inner spray pipe are connected with a rotating unit that drives them to rotate around their own axis and the rotation directions are opposite.

[0014] Preferably, in order to increase the probability of droplet collision, the inner spray holes are densely distributed on the circumferential inner wall of the outer nozzle barrel, the outer spray holes are densely distributed on the circumferential outer edge of the inner nozzle pipe, the outer nozzle barrel is provided with an outer spray cavity connected between the inner spray holes and the feed inlet, and the inner nozzle pipe is provided with an inner spray cavity connected between the outer spray holes and the feed inlet.

[0015] Preferably, in order to ensure stable operation of the rotating unit, the rotating unit is connected to the outer nozzle and the inner nozzle by magnetic coupling transmission.

[0016] In summary, compared with the prior art, the skid-mounted MVR evaporator of the present invention allows the heated feed liquid to spiral upward along the wall of the separation tube into the separator through the tangential tube. On the one hand, it can flush the wall of the separation tube to prevent scaling while allowing crystals to fall into the sedimentation tank. On the other hand, the feed liquid enters the separator at a certain initial velocity, promoting uniform mixing of high and low temperature feed liquids, avoiding violent boiling, and making evaporation more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the first embodiment; Figure 2 is a schematic structural diagram of the demister in the first embodiment; Figure 3 is a schematic structural diagram of a demister in a second embodiment; Figure 4 yes Figure 3 A schematic diagram of the cross-sectional structure of; Figure 5 yes Figure 4 A front view of Figure 6 yes Figure 3 Explosion diagram of Figure 7 yes Figure 3 Schematic diagram of the explosion from another perspective; In the figure: 1. Frame; 11. Underframe; 12. Bracket; 2. Separator; 21. Steam outlet; 22. Circulation pipe; 221. Feed inlet; 23. Separation pipe; 231. Diameter-expanded section; 232. Equal-diameter section; 24. Settling tank; 3. Discharge pump; 4. Heater; 41. Heat medium inlet; 42. Heat medium outlet; 421. Drain valve; 43. Heating inlet; 44. Heating outlet; 45. Tangential pipe; 46. Heated pipe; 5. Circulation pump; 6. Demister; 61. Feed inlet; 62. Liquid outlet; 63. Steam outlet; 64. Liquid seal anti-backflow pipe; 65. Concentric shaft; 7. Demisting assembly; 71. Cyclone tube; 711. Spiral ribbon; 72. Wire mesh packing; 73. Deflector block; 731. Protrusion; 74. Outer spray tube; 741. Inner spray hole; 742. Outer spray cavity; 75. Inner spray tube; 751. Outer spray hole; 752. Inner spray cavity; 76. Sealing pipe; 77. Connecting pipe; 771. Communication hole; 78. Convex ring; 781. Injection hole; 79. Sealing cover; 8. Compressor; 9. Rotating unit; 91. Driving unit; 911. Rotating motor; 912. Driving gear; 913. Driven gear; 914. Bearing; 915. Outer magnetic ring; 916. Inner magnetic ring; 92. Transmission unit; 921. Planet carrier; 922. Sun gear; 923. Planet gear; 924. Ring gear. Detailed implementation manners

[0018] The following combines the accompanying drawings and embodiments to further describe the detailed implementation manners of the present invention. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0019] First embodiment

[0020] As Figure 1 and Figure 2 shown, a skid-mounted MVR evaporator according to the first embodiment of the present invention includes a frame 1, and the following are arranged on the frame 1: A separator 2, with a steam outlet 21 at the top, a circulation pipe 22 fixedly connected to the bottom, and a separation pipe 23 extending in the vertical direction. A feed inlet 221 is provided on the side wall of the circulation pipe 22, and the bottom of the separation pipe 23 is fixedly connected to a settling tank 24; A discharge pump 3, with the input end communicating with the settling tank 24; A heater 4, having a heat medium inlet 41, a heat medium outlet 42, a heating inlet 43, and a heating outlet 44. A drain valve 421 is connected to the heat medium outlet 42. The heating outlet 44 is fixedly connected to the separation pipe 23 through a tangential pipe 45. The tangential pipe 45 extends in the horizontal direction perpendicular to the separation pipe 23 and the inner wall is tangent to the inner wall of the separation pipe 23; A circulation pump 5, communicating between the circulation pipe 22 and the heating inlet 43; The demister 6 has a feed inlet 61, a liquid outlet 62 and a steam outlet 63, and a demisting component 7 is provided inside. The liquid outlet 62 is communicated with the separator 2 through a liquid seal anti-backflow pipe 64; The compressor 8 is communicated between the steam outlet 63 and the heat medium inlet 41.

[0021] When the skid-mounted MVR evaporator of this embodiment operates, it mainly includes the following steps: S10. Feeding: The liquid material containing solute is fed into the circulation pipe 22 through the feed port 221 under the action of the feed pump and flows therein; S20. Circulation: Under the action of the circulation pump 5, the liquid material is driven to pass through the inside of the heater 4 and then enter the separation pipe 23. After being evaporated and concentrated in the separation pipe 23, it falls into the circulation pipe 22 and is then transported by the circulation pump 5 into the heater 4 for circulating flow; S30. Heating: Live steam or compressed secondary steam is used as the heating medium and introduced into the heater 4 to exchange heat with the liquid material, so that the liquid material is heated to boiling, and the live steam or compressed secondary steam as the heat source condenses to form condensed water; S40. Evaporation: After being heated, the liquid material enters the separator 2 through the separation pipe 23. In the separator 2, due to the pressure reduction, part of the solvent is quickly vaporized to form a vapor-liquid mixture. When passing through the separation pipe 23, the liquid phase and the gas phase are separated by using gravity and centrifugal force. The concentrated liquid material sinks to the bottom of the separator 2, and the unevaporated liquid material continues to participate in the circulation; The secondary steam containing droplets rises and enters the demister 6; S50. Vapor-liquid separation: The secondary steam containing droplets, that is, the vapor-liquid mixture, passes through the demisting component 7 inside the separator 2. The demisting component 7 performs vapor-liquid separation on the vapor-liquid mixture. After separation, the evaporated liquid material, under the action of gravity, flows back into the separator 2 through the liquid seal anti-backflow pipe 64 and then enters the heater 4 again through the circulation pipe 22 and the circulation pump 5 for heating treatment. The liquid material is continuously heated and evaporated to reach a saturated state, and the solute begins to crystallize out. As the evaporation continues, the crystals grow continuously and fall into the sedimentation tank 24 at the bottom through the separation pipe 23, while the separated clean steam enters the compressor 8. Since most of the droplets are removed from the secondary steam entering the compressor 8 by the demisting component 7, it avoids the corrosion damage caused by the droplets entering the compressor 8 and affects the working efficiency and service life of the compressor 8; S60. Steam compression: The purified dry secondary steam is mechanically pressurized by the compressor 8 to increase its temperature and pressure, and after its heat content increases, the secondary steam is used as the heat source for heating the liquid material and transported into the heater 4. Open the drain valve 421 to facilitate the discharge of the condensed water formed after the secondary steam is heated; S70. Discharging: The concentrated liquid sinks to the settling tank 24 at the bottom of the separator 2, and the concentrated liquid is transported to the downstream treatment unit through the discharge pump 3, such as a subsequent solid-liquid separation treatment device.

[0022] Compared with the prior art, in this embodiment, the heating outlet 44 of the heater 4 is fixedly communicated with the separation tube 23 through a tangential tube 45. The tangential tube 45 extends along a horizontal direction perpendicular to the inner wall of the separation tube 23 and is tangent to the inner wall of the separation tube 23. Thus, when the feed liquid passes through the heater 4 and the tangential tube 45, the formed high-temperature water flow can enter the separation tube 23 along the tangent direction. Affected by the centrifugal force, the high-temperature feed liquid flows spirally upward along the inner wall of the separation tube 23, flushing the inner wall of the separation tube 23 and entering the separator 2. After adopting the above structure: First, due to the flushing action of the high-temperature feed liquid, the crystals on the inner wall of the separation tube 23 can be removed, avoiding the inner wall structure of the separation tube 23; Second, while the high-temperature feed liquid rises along the spiral trajectory, the larger crystal particles attached to the inner wall of the separation tube 23 are affected by the gravity and deposit downward into the settling tank 24, ensuring the thickness of the feed liquid in the settling tank 24, facilitating the discharge pump 3 to pump away the crystal slurry for solid-liquid separation treatment; Finally, the feed liquid flowing upward along the spiral trajectory can enter the separator 2 at a certain speed, flushing the evaporation solution in the separator 2, mixing the high-temperature solution and the low-temperature solution, thereby promoting the uniform mixing of the feed liquid, ensuring more uniform evaporation, improving the evaporation effect, avoiding the phenomenon of local overheating and boiling of the solution, and damaging the internal components of the separator 2 due to the use of the separator 2.

[0023] In this embodiment, the frame 1 includes a horizontal bottom frame 11 and a support 12 fixed above the bottom frame 11. The support 12 is in an inverted U shape. The discharge pump 3, the heater 4, and the circulation pump 5 are all fixed above the bottom frame 11 and inside the support 12. The heater 4 is horizontally arranged. The separator 2 and the compressor 8 are both fixed directly above the support 12, and their length directions are consistent with the length direction of the bottom frame 11. The separator 2 adopts a horizontal separator 2, which has a larger cross-section, facilitating the evaporation of the solvent of the feed liquid. The separation tube 23 and the circulation tube 22 are both fixedly penetrated through the support 12, and the settling tank 24 is adjacent to the upper part of the bottom frame 11; the heater 4 is horizontally arranged, and its length direction is perpendicular to the length direction of the separator 2; the demister 6 is fixed directly above the separator 2; the separator 2, the discharge pump 3, the heater 4, the circulation pump 5, the demister 6, and the compressor 8 are closely arranged adjacent to each other to ensure the compactness of the overall structure of the device, save the occupied space, and facilitate transportation.

[0024] A further improvement is that the separation tube 23 includes a diameter-expanded section 231 and an equal-diameter section 232 that are connected coaxially from bottom to top. The equal-diameter section 232 is cylindrical. The inner diameter of the diameter-expanded section 231 increases sequentially from bottom to top, and the inner diameter at the top is the same as that of the equal-diameter section 232. The diameter-expanded section 231 is connected to the tangential tube 45.

[0025] More specifically, the tangential tube 45 is connected to the lower part of the diameter-expanded section 231. After adopting this design, when ensuring that the heated liquid flows out of the tangential tube 45, its speed is fixed. The inner diameter at the bottom of the diameter-expanded section 231 is small, so that when the liquid flows along the inner wall of the diameter-expanded section 231, a greater centrifugal force can be generated to ensure the scouring effect on the diameter-expanded section 231 and avoid crystal particles from depositing on the diameter-expanded section 231 at a low position. Moreover, due to the generation of a greater centrifugal force, the liquid can flow upward along a spiral trajectory. The equal-diameter section 232 is cylindrical, which limits the maximum inner diameter of the separation tube 23, avoiding an overly large inner diameter that may cause the liquid flow rate to be too slow and the liquid to sink, making it impossible to enter the separator 2 and difficult to ensure the scouring effect on the separation tube 23.

[0026] A further improvement is that at least two layers of heat-receiving tubes 46 that are distributed vertically and in a serpentine shape are arranged in the heater 4. The heat-receiving tubes 46 are connected between the heating inlet 43 and the heating outlet 44.

[0027] With the above structural design, while ensuring that the internal space of the heater 4 is fixed and limited, the flow path length of the liquid is extended, and at the same time, the cross-sectional area of the flow path is reduced. On the basis of the fixed power of the circulation pump 5, the liquid can pass through the heat-receiving tubes 46 in the heater 4 at a faster speed. Moreover, due to the extension of the length of the heat-receiving tubes 46, ensuring the wall length and number of layers of the heat-receiving tubes 46, the heat-receiving tubes 46 have sufficient heat exchange area, and there is always liquid passing through the heat-receiving tubes 46. Therefore, the heat exchange efficiency between the heat source (i.e., live steam and secondary steam after doing work) and the liquid inside the heat-receiving tubes 46 is ensured, the heat exchange amount is increased, the energy consumption is further reduced, and the MVR has a more significant energy-saving effect.

[0028] In this embodiment, the demister 6 and the separator 2 are both horizontally arranged and their length directions are parallel. The demister 6 is closely arranged directly above the separator 2. In this way, the upper structure of the bracket 12 is more compact, saving occupied space and facilitating transportation.

[0029] A further improvement is that the defoaming assembly 7 includes a swirl tube 71 and a wire mesh filler 72 distributed in sequence, the swirl tube 71 is axially parallel to the axial direction of the demister 6, and a spiral bond 711 is provided on the circumferential inner wall of the swirl tube 71 to guide the steam mixture through the swirl tube 71 along a spiral trajectory, and the swirl tube 71 is densely distributed at one end of the demister 6 adjacent to the steam outlet 21; there are two spiral bonds 711 with opposite thread directions, and the axial ends of the two spiral bonds 711 are flush with the axial position on the inner side of the swirl tube 71.

[0030] In addition, the defoaming assembly 7 also includes a guide block 73 fixed in the demister 6, the guide block 73 is located on the side of the wire mesh filler 72 away from the swirl tube 71, and the side of the guide block 73 adjacent to the wire mesh filler 72 is a conical surface coaxial with the demister 6. Specifically, the tip of the guide block 73 faces the wire mesh filler 72, and there is a gap between the guide block 73 and the circumferential inner wall of the demister 6 for secondary steam to pass through; the circumferential outer edge of the wire mesh filler 72 is fixedly connected to the circumferential inner wall of the demister 6.

[0031] After adopting the above structure, when the vapor-liquid mixture, that is, the secondary steam mixed with liquid droplets, enters the demister 6 from the feed port 61, it passes through the demister assembly 7 formed by the swirl tube 71, the wire mesh filler 72 and the guide block 73 in sequence. Through three defoaming treatments, the dryness and cleanliness of the secondary steam discharged from the steam outlet 63 are ensured, and the liquid droplets in the secondary steam entering the compressor 8 are greatly reduced, thereby ensuring the normal, high-speed and stable operation of the compressor 8.

[0032] More specifically, the spiral bond 711 is disposed at one end of the swirl tube 71 adjacent to the feed inlet 61. Thus, when the fluid of the vapor-liquid mixture enters the swirl tube 71 from the feed inlet 61, it is affected by the guiding effect of the spiral bond 711, and the vapor-liquid mixture flows along the inner wall of the swirl tube 71. In the process of flowing along the inner wall of the swirl tube 71, the vapor-liquid mixture contacts the inner wall of the swirl tube 71, so that the droplets in the vapor-liquid mixture adhere to the inner wall of the swirl tube 71. Finally, as the flow path in the swirl tube 71 increases, the droplets attached to the inner wall of the swirl tube 71 and flowing with the secondary steam gradually accumulate. The liquid is gathered into a larger size and is affected by the driving force of the secondary steam flow. The larger droplets are discharged from the cyclone tube 71, accumulated in the demister 6, and then enter the separator 2 through the liquid-sealed anti-backflow pipe 64; a small amount of droplets not attached to the inside of the cyclone tube 71 come into contact with the wire mesh filler 72 and the guide block 73 when passing through the two, and are attached to the wire mesh filler 72 and the guide block 73 to form small droplets. As the number of attached droplets increases, the small droplets gradually accumulate into large droplets, are deposited at the bottom of the demister 6, and enter the separator 2 through the liquid-sealed anti-backflow pipe 64.

[0033] In summary, when the skid-mounted MVR evaporator of this embodiment operates, after the raw material liquid enters the system through the feed pump, an initial material flow is formed. The liquid is driven by the circulation pump 5 and forced to flow out at a certain flow rate into the tube side inside the heating tubes 46 of the horizontal tube heater 4. The design of high-speed flow can not only improve the heat transfer efficiency but also effectively reduce the risk of tube wall structure. In the heater 4, the liquid exchanges heat countercurrently with the high-temperature compressed steam (100 - 120°C) in the shell side. The temperature of the material rapidly rises above the boiling point, and part of the liquid water vaporizes into secondary steam, forming a violently disturbed gas-liquid two-phase flow. At this time, the concentration of the material significantly increases due to water evaporation.

[0034] Subsequently, the liquid flows out from the tangential tube 45 and enters the separator 2 at a high speed in a tangential manner in the enlarged diameter section 231. When passing through the separation tube 23, phase separation is achieved under the dual action of centrifugal force and gravity; the crystal particles fall into the settling tank 24, and the liquid spirally rises into the separator 2 for evaporation. The gas phase carries trace liquid droplets and rises to the top of the separator 2, enters the demister 6 for further purification, and the liquid droplets in the gas phase are removed through the demisting component 7, reducing the steam humidity to below 0.1% and avoiding the risk of liquid slugging in the subsequent compressor 8; the purified steam is pressurized and heated by the compressor 8 to form a high-temperature heat source and returns to the shell side of the heater 4 to release latent heat by countercurrent heat exchange with the liquid in the heating tubes 46, and condenses into liquid water by itself and is discharged through the heat medium outlet 42; the above process reduces the dependence on external live steam by compressing and recycling the latent heat of the secondary steam.

[0035] Second Embodiment

[0036] As Figures 3 - 7 shown, a skid-mounted MVR evaporator according to the second embodiment of the present invention is based on the first embodiment, and the difference is that the demisting component 7 includes an outer spray cylinder 74 and an inner spray pipe 75. Both the outer spray cylinder 74 and the inner spray pipe 75 are arranged on the side of the wire mesh packing 72 facing away from the guide block 73. The outer spray cylinder 74, the inner spray pipe 75, and the demister 6 are coaxial, and the outer spray cylinder 74 is sleeved outside the inner spray pipe 75. Inner spray holes 741 and outer spray holes 751 are respectively arranged on the circumferential inner wall of the outer spray cylinder 74 and the circumferential outer edge of the inner spray pipe 75. The inner spray holes 741 and the outer spray holes 751 are both communicated with the feed port 61. The outer spray cylinder 74 and the inner spray pipe 75 are connected with a rotating unit 9 that drives them to rotate around their own axis and in opposite rotation directions; the inner spray pipe 75 is fixedly connected to the wire mesh packing 72 and the guide block 73, and the circumferential outer edge of the wire mesh packing 72 is hermetically attached to the circumferential inner wall of the demister 6.

[0037] A further improvement is that the inner spray holes 741 are densely distributed on the circumferential inner wall of the outer spray barrel 74, the outer spray holes 751 are densely distributed on the circumferential outer edge of the inner spray pipe 75, the outer spray barrel 74 is provided with an outer spray cavity 742 connected between the inner spray holes 741 and the feed inlet 61, and the inner spray pipe 75 is provided with an inner spray cavity 752 connected between the outer spray holes 751 and the feed inlet 61. Two liquid outlets 62 are provided, one of which is located between the inner spray pipe 75 and the wire mesh filler 72, and the other is located between the wire mesh filler 72 and the guide block 73.

[0038] After adopting the above design, the gas-liquid mixture formed by the secondary steam carrying the liquid droplets enters the demister 6 through the feed port 61 and is divided into at least two paths, one of which enters the outer spray chamber 742 of the outer spray barrel 74 and is sprayed inward from the inner spray hole 741, while the other enters the inner spray chamber 752 of the inner spray pipe 75 and is sprayed outward from the outer spray hole 751. At the same time, the rotating unit 9 drives the outer spray barrel 74, the inner spray pipe 75, the wire mesh filler 72 and the guide block 73 to rotate along the axis of the demister 6. The center line is used as the center line for rotation, thereby increasing the probability of the vapor-liquid mixture sprayed inward from the inner spray hole 741 and the vapor-liquid mixture sprayed outward from the outer spray hole 751 colliding with each other, so that the small droplets in the two vapor-liquid mixtures collide with each other and combine to form large droplets, which are convenient for discharge from the liquid outlet 62 between the inner nozzle 75 and the wire mesh filler 72. Both liquid outlets 62 are connected to the separator 2 through the liquid seal anti-backflow pipe 64, so that the accumulated liquid enters the separator 2.

[0039] The inner spray holes 741 are densely distributed on the circumferential inner wall of the outer spray barrel 74, and the outer spray holes 751 are densely distributed on the circumferential outer edge of the inner spray pipe 75, so that multiple airflows are formed in the demister 6, further increasing the probability of droplet collision; reducing the droplet content in the secondary steam, so that the secondary steam with reduced droplet content passes through the wire mesh filler 72 and the guide block 73, and the rotating unit 9 can also drive the wire mesh filler 72 and the guide block 73 to rotate, thereby avoiding blockage of the wire mesh filler 72. At the same time, the small droplets formed on the guide block 73 generate centrifugal force after the guide block 73 rotates, which is convenient for deposition at the bottom of the demister 6, and then discharged from the liquid outlet 62, thereby further improving the vapor-liquid separation effect on the vapor-liquid mixture.

[0040] A further improvement is that the rotating unit 9 is connected to the outer nozzle 74 and the inner nozzle 75 by magnetic coupling transmission.

[0041] This design ensures the stable operation of the rotating unit 9 and prevents the rotating unit 9 from being affected by the high temperature and humidity inside the demister 6, so that the guide block 73, the wire mesh filler 72, the outer nozzle 74 and the inner nozzle 75 can rotate stably.

[0042] In this embodiment, a coaxial shaft 65 coaxial with the demister 6 is provided inside the demister 6. The coaxial shaft 65 is fixedly passed through the wire mesh filler 72 and the two ends are respectively fixedly connected to the guide block 73 and the inner nozzle 75 coaxially. In this way, a relatively fixed connection is achieved between the inner nozzle 75, the wire mesh filler 72 and the guide block 73.

[0043] The rotating unit 9 includes a driving unit 91 and a transmission unit 92. The inner nozzle 75 and the outer nozzle 74 are connected via the transmission unit 92, so that the inner nozzle 75 and the outer nozzle 74 rotate in opposite directions, further increasing the collision probability of droplets in the two vapor-liquid mixtures ejected from the inner nozzle 75 and the outer nozzle 74.

[0044] The driving unit 91 is drivingly connected to the guide block 73, so that after the driving unit 91 is running, it can drive the guide block 73 to rotate with the axis of the demister 6 itself as the center line.

[0045] The driving unit 91 includes a rotating motor 911, the output end of the rotating motor 911 is fixedly connected with a driving gear 912 coaxially, a driven gear 913 meshing with the driving gear 912 is arranged directly below the driving gear 912, the driven gear 913 is a ring gear and a bearing 914 is arranged inside, the outer ring of the bearing 914 is fixedly connected to the circumferential inner wall of the driven gear 913, and the inner ring is fixedly sleeved on the steam outlet pipe connected to the steam outlet 63; the driven gear 913 is fixedly connected with an outer magnetic ring 915 coaxially, the guide block 73 is provided with a protrusion 731 on a side adjacent to the steam outlet 63, the protrusion 731 is fixedly connected with an inner magnetic ring 916, the outer magnetic ring 915 and the inner magnetic ring 916 are coaxially and closely adjacent.

[0046] In this way, when the rotating motor 911 is started, it drives the driving gear 912 to rotate, so that the driven gear 913 rotates under the action of the bearing 914, driving the outer magnetic ring 915 to rotate, acting on the inner magnetic ring 916 on the inner side of the demister 6, so that the inner magnetic ring 916 rotates, and acts on the guide block 73 through the protrusion 731, thereby causing the guide block 73 to rotate.

[0047] The transmission unit 92 is a planetary gear, specifically, includes a planet carrier 921 fixedly connected to the inner wall of the demister 6, the planet carrier 921 is provided with a sun gear 922 and a planet gear 923 rotating around its own axis, the planet gear 923 is distributed in an annular array on the outside of the sun gear 922 and meshed with the sun gear 922, the outside of the sun gear 922 is provided with a gear ring 924 meshing therewith, the gear ring 924 and the sun gear 922 are respectively fixedly connected to the outer nozzle 74 and the inner nozzle 75 coaxially.

[0048] Thus, after the driving unit 91 drives the diversion block 73 to rotate, the inner spray pipe 75 is driven to rotate by the concentric shaft 65, so that the sun gear 922 rotates. The sun gear 922 acts on the ring gear 924 through the planet gear 923, causing the ring gear 924 to drive the outer spray cylinder 74. Finally, the outer spray cylinder 74 and the inner spray pipe 75 rotate in opposite directions.

[0049] One side of the outer spray cylinder 74 and the inner spray pipe 75 adjacent to the wire mesh packing 72 is hermetically arranged. The other end of the inner spray pipe 75 is fixedly connected with a connecting pipe 77 and a sealing pipe 76 in sequence along the coaxial line. The pipe orifice of the sealing pipe 76 is hermetically attached to the feeding port 61. The sealing pipe 76 fixedly penetrates through the sun gear 922 and hermetically penetrates through the planet carrier 921.

[0050] Sealing covers 79 and convex rings 78 are fixedly connected to the outer circumferential edges of both ends of the connecting pipe 77 along the coaxial line. The sealing cover 79 is located between the feeding port 61 and the convex ring 78. The sealing cover 79 is hermetically attached to the outer circumferential inner wall of the outer spray cylinder 74. The convex ring 78 is hermetically attached to one end of the inner side of the outer spray cylinder 74 close to the feeding port 61, so that the convex ring 78, the sealing cover 79 and the outer spray cylinder 74 enclose to form a spraying cavity. Communication holes 771 are annularly arranged on the circumferential inner wall of the connecting pipe 77. The communication holes 771 communicate between the spraying cavity and the lumen of the connecting pipe 77. Spraying holes 781 are annularly arranged on the convex ring 78. The orifices at both ends of the spraying holes 781 communicate with the spraying cavity and the gap between the inner spray pipe 75 and the outer spray cylinder 74 respectively. The axial directions of the inner spraying holes 741 and the outer spraying holes 751 are both perpendicular to the axis of the demister 6. The axial direction of the spraying holes 781 is parallel to the axis of the demister 6.

[0051] After adopting the above structure, the vapor-liquid mixture enters the sealed pipe 76 through the feed port 61. When passing through the connecting pipe 77, the vapor-liquid mixture is divided into two paths. One path enters the inner spray pipe 75 and sprays outward from the outer spray holes 751 on the side wall of the inner spray pipe 75. The other path enters the spray chamber through the communication hole 771. The vapor-liquid mixture in the spray chamber is further divided into two paths. One path enters the outer spray chamber 742 of the outer spray cylinder 74 and sprays inward from the inner spray holes 741, contacting the vapor-liquid mixture spraying outward from the outer spray holes 751 to promote the aggregation of small droplets. The remaining vapor-liquid mixture is sprayed into the space between the outer spray cylinder 74 and the inner spray pipe 75 along the axis of the demister 6 through the spray holes 781. On the one hand, dividing the original single stream of vapor-liquid mixture into multiple streams for contact enables the small droplets carried by the multiple streams of vapor-liquid mixture to aggregate into large droplets. On the other hand, the airflow ejected from the spray holes 781 imparts a velocity to the droplets and the airflow towards the wire mesh packing 72, causing the large droplets to flow out of the gap between the outer spray cylinder 74 and the inner spray pipe 75 and fall into the liquid outlet 62 between the wire mesh packing 72 at the bottom of the demister 6 and the inner spray pipe 75, and then return to the separator 2 through the liquid seal anti-backflow pipe 64 connected to the liquid outlet 62 for continuous evaporation treatment. In this way, the droplets on the wire mesh packing 72 can also be reduced, facilitating the flow of the airflow, thereby avoiding the blockage of the wire mesh packing 72 and ensuring the smooth progress of vapor-liquid separation.

[0052] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A skid-mounted MVR evaporator, comprising a frame, characterized in that, The frame is provided with: The separator has a steam outlet at the top, a circulating pipe and a separation pipe extending in the vertical direction fixedly connected at the bottom, a feed port is provided on the side wall of the circulating pipe, and a sedimentation tank is fixedly connected at the bottom of the separation pipe; A discharge pump, the input end of which is connected to the sedimentation tank; The heater has a heat medium inlet, a heat medium outlet, a heating inlet and a heating outlet, wherein the heat medium outlet is connected to a drain valve, and the heating outlet is fixedly connected to the separation tube through a tangential tube, wherein the tangential tube extends in a horizontal direction perpendicular to the separation tube and the inner wall of the tangential tube is tangential to the inner wall of the separation tube; A circulation pump connected between the circulation pipe and the heating inlet; A demister having a material inlet, a liquid outlet and a steam outlet and a built-in demister assembly; The compressor is connected between the steam outlet and the heat medium inlet.

2. The skid-mounted MVR evaporator according to claim 1, wherein: The separation tube includes an expanded diameter section and a constant diameter section which are connected from bottom to top and have the same centerline. The constant diameter section is cylindrical. The inner diameter of the expanded diameter section increases from bottom to top and the inner diameter of the top is consistent with the inner diameter of the constant diameter section. The expanded diameter section is connected to the tangential tube.

3. The skid-mounted MVR evaporator according to claim 2, characterized in that: At least two layers of serpentine heat receiving pipes distributed in a vertical direction are arranged in the heater, and the heat receiving pipes are connected between the heating inlet and the heating outlet.

4. The skid-mounted MVR evaporator according to claim 1, wherein: The liquid outlet is communicated with the separator through a liquid-sealed anti-backflow pipe.

5. The skid-mounted MVR evaporator according to claim 1, wherein: The demister and the separator are both arranged horizontally and their length directions are parallel.

6. The skid-mounted MVR evaporator according to claim 5, characterized in that: The defoaming assembly includes a swirl tube and a wire mesh filler distributed in sequence. The swirl tube is axially parallel to the axial direction of the demister. The circumferential inner wall of the swirl tube is provided with a spiral bond to guide the steam mixture to pass through the swirl tube along a spiral trajectory. The swirl tubes are densely distributed at one end of the demister adjacent to the steam outlet.

7. The skid-mounted MVR evaporator according to claim 6, characterized in that: The spiral ties are provided with two and the thread directions are opposite, and the axial ends of the two spiral ties at the swirl tube are flush with the axial positions of the inner side of the swirl tube.

8. The skid-mounted MVR evaporator according to claim 1, wherein: The defoaming assembly includes an outer nozzle and an inner nozzle pipe, the outer nozzle, the inner nozzle pipe and the defoamer are coaxial and the outer nozzle is sleeved outside the inner nozzle pipe, an inner spray hole and an outer spray hole are respectively provided on the circumferential inner wall of the outer nozzle and the circumferential outer edge of the inner nozzle pipe, the inner spray hole and the outer spray hole are both connected to the feed port, and the outer nozzle and the inner nozzle pipe are connected to a rotating unit that drives the two to rotate around their own axis and in opposite directions.

9. The skid-mounted MVR evaporator according to claim 8, wherein: The inner spray holes are densely distributed on the circumferential inner wall of the outer nozzle barrel, the outer spray holes are densely distributed on the circumferential outer edge of the inner nozzle pipe, the outer nozzle barrel is provided with an outer spray cavity connected between the inner spray holes and the feed inlet, and the inner nozzle pipe is provided with an inner spray cavity connected between the outer spray holes and the feed inlet.

10. The skid-mounted MVR evaporator according to claim 8, wherein: The rotating unit is connected to the outer nozzle and the inner nozzle by magnetic coupling transmission.

Images