MVR evaporation crystallizer suitable for high-salt wastewater and use method thereof

Abstract

The application discloses a kind of MVR evaporation crystallizers suitable for high salt wastewater and use method, belong to evaporation crystallizer field, including falling film evaporation part, circulating pump, separation part and compressor;The liquid discharge end of the falling film evaporation part is connected with the input end of circulating pump by reflux pipeline, and the output end of the circulating pump is connected with the liquid inlet end of the falling film evaporation part by liquid sending pipeline;The falling film evaporation part is communicated with the separation part by aeration pipeline and flow guide pipeline, and the exhaust end of the separation part is connected with the input end of cyclone separator, and the exhaust end of the cyclone separator is connected with the input end of compressor;The application constructs the three-stage separation scheme from rough to fine, can capture droplet of different physical characteristics;Can greatly reduce the liquid-carrying capacity of secondary steam, directly protect core equipment;For the case that wastewater composition is complex or processing capacity has certain fluctuation, the application provides higher safety margin and operation flexibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of evaporation crystallizers, more particularly to an MVR evaporation crystallizer suitable for high-salt wastewater and a use method thereof. BACKGROUND

[0002] In industrial production, treating wastewater is an important measure for environmental protection, and the MVR evaporation crystallizer is a device commonly used for wastewater treatment, which greatly reduces the consumption of external steam by reusing the energy of secondary steam generated in the evaporation process, and is applied to industries that need to treat a large amount of liquid or recover solutes, and is widely used in the environmental protection industry of high-salt wastewater treatment.

[0003] In the MVR system, the compressor is the heart of the MVR, but its operating environment is extremely harsh. If the demister of the separator is not well designed, or the operating load is too high, tiny liquid droplets (containing salt) will be brought into the secondary steam, and after these salt-containing liquid droplets enter the high-speed rotating compressor blades, the water evaporates and the salt is deposited on the blades. This will cause the rotor to be out of balance, causing strong vibration, and in severe cases, even the blade will be broken or the bearing will be burned out. SUMMARY

[0004] In view of the problems existing in the prior art, the purpose of the present application is to provide an MVR evaporation crystallizer suitable for high-salt wastewater and a use method thereof.

[0005] To solve the above problems, the technical scheme adopted by the present application is as follows.

[0006] An MVR evaporation crystallizer suitable for high-salt wastewater, comprising a falling film evaporation part, a circulating pump, a separation part and a compressor;

[0007] The liquid discharge end of the falling film evaporation part is connected to the input end of the circulating pump through a reflux pipeline, and the output end of the circulating pump is connected to the liquid inlet end of the falling film evaporation part through a liquid feeding pipeline; the falling film evaporation part is connected to the separation part through an air supply pipeline and a flow guide pipeline, the exhaust end of the separation part is connected to the input end of the cyclone separator, the exhaust end of the cyclone separator is connected to the input end of the compressor, and the output end of the compressor is connected to the air inlet end of the falling film evaporation part;

[0008] The separation part comprises a shell one, a baffle demisting part and a wire mesh demisting part fixed on the inner wall of the shell one, and the wire mesh demisting part is located above the baffle demisting part; the baffle demisting part comprises a hollow ring body fixed on the inner wall of the shell one and a plurality of baffle plates fixed on the inner wall of the hollow ring body.

[0009] Further, the hollow ring body is internally provided with a flow channel one and a flow channel two, the flow channel one is communicated with the plurality of pipes, and an input end of the flow channel one is connected with the liquid inlet part one.

[0010] Further, the outer surface of the plurality of baffle plates is provided with a liquid outlet one, the inner part of the plurality of baffle plates is provided with a flow channel three, the flow channel three in the inner part of the baffle plate is communicated with the flow channel two in the inner part of the hollow ring body, and the lower end of the hollow ring body is fixedly connected with a liquid outlet part.

[0011] Further, the outer surface of the shell one is provided with a reserved port, and the lower end of the shell one is provided with a liquid outlet two.

[0012] Further, the inner wall of the shell one is further connected with a flow equalizing part, and the flow equalizing part comprises a plate body fixedly connected to the inner wall of the shell one and a plurality of through holes provided in the inner part of the plate body.

[0013] Further, the upper end of the plate body is integrally formed with a plurality of hollow annular flanges, the inner wall of the hollow annular flange is provided with an annular liquid distribution groove, the upper end of the hollow annular flange is fixedly connected with a liquid inlet part two, and the inner part of the hollow annular flange is provided with a flow channel four communicated with the liquid inlet part two and the annular liquid distribution groove.

[0014] Further, the axial cyclone demisting part connected between the exhaust end of the cyclone separator and the input end of the compressor, and the axial cyclone demisting part comprises a shell two connected with the exhaust end of the cyclone separator and the input end of the compressor at two ends, a hollow cyclone ring fixedly connected in the inner part of the shell two, an inlet end and a diffusion end provided in the inner part of the hollow cyclone ring, a throat part provided in the inner part of the hollow cyclone ring and communicated with the inlet end and the diffusion end, a cyclone vane fixedly connected to the inner wall of the throat part, a plurality of liquid collecting cavities provided in the inner wall of the throat part, a liquid blocking weir integrally formed on the inner wall of the throat part, a liquid collecting groove provided in the hollow cyclone ring and communicated with the plurality of liquid collecting cavities, an anti-vortex baffle fixedly connected to the inner wall of the liquid collecting groove, an exhaust pipeline and a liquid discharge pipeline with one end penetrating through the shell two into the inner part of the hollow cyclone ring and communicated with the liquid collecting groove.

[0015] Further, the inner wall of the shell two is further fixedly connected with a horizontal flow flange, and the horizontal flow flange is located below the hollow cyclone ring; the inner part of the shell two is fixedly connected with a liquid supply pipeline, one end of the liquid supply pipeline fixedly connected with a nozzle two when extending into the inner part of the shell two, and the other end of the liquid supply pipeline penetrates through the shell two and extends outward.

[0016] Further, the outer part of the falling film evaporation part is provided with an exhaust port and a condensate water outlet, the backflow pipeline is provided with a drainage port, and the liquid supply pipeline is provided with a raw water inlet.

[0017] A method for using an MVR evaporation crystallizer suitable for high-salt wastewater, comprising the following steps:

[0018] Step 1, the wastewater enters the liquid feeding pipeline from the raw water inlet, the circulating pump sends the wastewater into the falling film evaporation part through the liquid feeding pipeline, the steam enters the falling film evaporation part and exchanges heat with the wastewater, the wastewater is heated and steam is generated; the generated steam enters the shell one through the air pipe;

[0019] Step 2, the steam enters the shell one first contacts the plate body, and passes through the through hole to reach the baffle demisting part, passes through between the plurality of baffles and reaches the wire mesh demisting part, and after passing through the wire mesh demisting part, is discharged from the shell one into the cyclone separator for gas-liquid separation;

[0020] Step 3, the separated steam enters the shell two, the steam is guided by the cyclone vane when passing through the throat part and generates cyclone at the throat part, the cyclone makes the liquid drops in the gas form liquid film on the inner wall of the throat part and flow, the liquid weir forces the liquid film to separate from the wall main flow and enter the liquid collecting groove; the gas discharged from the hollow cyclone ring is rectified by the horizontal flow flange to make it enter the compressor in the axial direction;

[0021] Step 4, the steam is compressed by the compressor and then input into the falling film evaporation part for heat exchange evaporation treatment of the wastewater.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] (1) The present scheme is provided with a baffle demisting part, a wire mesh demisting part and a cyclone separator, the airflow direction is changed through the baffle demisting part, the liquid drops with large mass are made to impact the plate wall and flow down by inertia, most of the obvious liquid produced by boiling and splashing is treated, and the load of the subsequent wire mesh is reduced; then the small liquid drops are captured, coalesced and finally separated by dropping by the wire mesh demisting part through the mechanisms of inertia collision, direct interception and Brown diffusion, most of the liquid water is removed before the steam leaves the separation chamber body, the steam dryness is greatly improved; finally, the cyclone separator is used for terminal separation of the liquid drops with density greater than the steam; a three-stage separation scheme from coarse to fine is constructed, and liquid drops with different physical properties can be captured; the liquid carrying amount of the secondary steam can be greatly reduced, and the core equipment is directly protected; for the case that the wastewater composition is complex or the treatment amount has certain fluctuation, the present application provides higher safety margin and operation flexibility.

[0024] (2) This scheme is equipped with a drain port and a nozzle. When the processing capacity of the equipment is small, the nozzle continuously sprays water to form a continuous downward flowing liquid film on the surface of the baffle plate. When the salt droplets hit this liquid film, they will be dissolved or washed away immediately, avoiding the deposition and caking of salt on the baffle plate. The salt is discharged through the drain port along with the flushing water. This gives the baffle demisting section a preliminary online self-cleaning capability, which can extend the operating cycle of the equipment. At the same time, the spray water has a certain cooling effect on the baffle plate, which can avoid the local overheating caused by the long-term contact of the baffle plate with high-temperature steam, which is conducive to the long-term stability of the equipment materials.

[0025] (3) This scheme is equipped with a flow equalization section, which can rectify the steam through multiple through holes. The steam is forced through these through holes to form a fine steam column with a more uniform velocity distribution; it creates ideal air intake conditions for the baffle plate and improves its separation efficiency; at the same time, the liquid discharged from the annular liquid distribution tank can form a downward flowing liquid film along the inner wall of the through hole. When the steam carrying salt droplets passes through the channel, the droplets hit the wet hole wall under the action of inertia, are captured, dissolved and carried away by the liquid film; it can remove some of the salt-containing droplets and significantly reduce the pollutant load in the subsequent baffle plate area; after the pre-washing of the flow equalization plate, the liquid content and salt content of the steam reaching the baffle plate have been greatly reduced, which reduces the separation pressure and scaling risk of the baffle plate.

[0026] (4) This scheme is equipped with an axial swirl demisting section. It uses the pressure difference of the compressor suction section to accelerate the steam at the throat and force the high-speed axial flow to be converted into a strong rotational flow through the swirl blades, so as to efficiently convert the kinetic energy of the steam into rotational energy. The strong centrifugal force generated by the rotation throws the residual micro-droplets and particles in the steam toward the throat wall and forms a downward spiral liquid film. The liquid film is forced to detach from the mainstream of the wall and enter the collection tank through the liquid weir. The mist droplets that still escape after the previous multi-stage separation are captured. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure One ;

[0028] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure Two ;

[0029] Figure 3 This is a cross-sectional view of the separation section of the present invention;

[0030] Figure 4 This is a schematic diagram of the deflector and demister structure of the present invention;

[0031] Figure 5 For the present invention Figure 3 Enlarged schematic diagram of the structure at point A in the middle;

[0032] Figure 6 Fig. 1 is a structural schematic diagram of the liquid inlet part of the application;

[0033] Figure 7 Fig. 2 is a structural schematic diagram of the flow equalizing part of the application;

[0034] Figure 8 Fig. 3 is an enlarged schematic diagram of the structure at B in the application; Figure 3

[0035] Figure 9 Fig. 4 is a three-dimensional structural schematic diagram of the axial cyclone mist eliminator part of the application;

[0036] Figure 10 Fig. 5 is a sectional view of the axial cyclone mist eliminator part of the application;

[0037] Figure 11 Fig. 6 is a sectional view of the hollow cyclone ring of the application.

[0038] Fig. 7 is a legend of the figures;

[0039] 1, falling film evaporation part; 11, reflux pipeline; 12, air pipeline; 13, flow guide pipeline; 14, water outlet; 15, exhaust outlet; 16, condensate outlet; 2, circulating pump; 21, liquid feeding pipeline; 22, raw water inlet; 3, separation part; 31, shell one; 32, reserved port; 33, baffle mist eliminator part; 331, hollow ring body; 332, baffle plate; 333, pipeline; 334, liquid inlet part one; 335, liquid outlet one; 336, nozzle one; 337, liquid discharge part; 34, wire mesh mist eliminator part; 35, liquid outlet two; 36, flow equalizing part; 361, plate body; 362, through hole; 363, hollow annular flange; 364, liquid inlet part two; 365, annular liquid distribution groove; 4, cyclone separator; 5, compressor; 6, axial cyclone mist eliminator part; 61, shell two; 62, hollow cyclone ring; 621, inlet end; 622, throat part; 623, diffusion end; 624, cyclone blade; 625, liquid collecting cavity; 626, liquid blocking weir; 627, liquid collecting groove; 628, exhaust pipeline; 629, liquid discharge pipeline; 630, anti-vortex baffle; 63, horizontal flow flange; 64, liquid supply pipeline; 65, nozzle two. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0041] Please refer to Figures 1 to 11 ​The application discloses a MVR evaporation crystallizer suitable for high-salt-content wastewater, which comprises a falling film evaporation part 1, a circulating pump 2, a separation part 3 and a compressor 5.

[0042] The liquid outlet end of the falling film evaporation part 1 is connected with the input end of the circulating pump 2 through a reflux pipeline 11, and the output end of the circulating pump 2 is connected with the liquid inlet end of the falling film evaporation part 1 through a liquid feeding pipeline 21; the falling film evaporation part 1 is connected with the separation part 3 through an air feeding pipeline 12 and a flow guiding pipeline 13, the gas outlet end of the separation part 3 is connected with the input end of a cyclone separator 4, the gas outlet end of the cyclone separator 4 is connected with the input end of the compressor 5, and the output end of the compressor 5 is connected with the gas inlet end of the falling film evaporation part 1.

[0043] The separation part 3 comprises a shell 31, a baffle demisting part 33 and a wire mesh demisting part 34 fixed on the inner wall of the shell 31, and the wire mesh demisting part 34 is located above the baffle demisting part 33; the baffle demisting part 33 comprises a hollow ring body 331 fixed on the inner wall of the shell 31 and a plurality of baffle plates 332 fixed on the inner wall of the hollow ring body 331.

[0044] An exhaust port 15 and a condensate water outlet 16 are arranged outside the falling film evaporation part 1, a water outlet 14 is arranged on the reflux pipeline 11, and a raw water inlet 22 is arranged on the liquid feeding pipeline 21.

[0045] By adopting the above technical scheme, the wastewater enters the liquid delivery pipeline 21 from the raw water inlet 22, the circulating pump 2 sends the wastewater into the falling film evaporation part 1 through the liquid delivery pipeline 21, the steam enters the falling film evaporation part 1 and exchanges heat with the wastewater, the wastewater is heated and steam is generated; the steam generated in the heat exchange process of the wastewater will reach the lower part of the falling film evaporation part 1 together with the wastewater, and the steam will enter the shell one 31 through the air pipe 12, the concentrated wastewater in the falling film evaporation part 1 is returned to the circulating pump 2 through the backflow pipeline 11 to continue the circulating treatment, and the concentrated wastewater can be discharged through the water outlet 14; the non-condensable gas in the falling film evaporation part 1 can be discharged from the exhaust port 15, and the condensed water outside the heat exchange pipeline in the falling film evaporation part 1 can be discharged from the condensed water outlet 16; the falling film evaporation part 1 belongs to mature prior art, and its principle and structure will not be described here; the steam enters the shell one 31 and rises and passes between the plurality of baffle plates 332, the airflow direction is changed through the baffle plates 332, the liquid droplets with large mass are made to impact the plate wall and gather and flow down by inertia, most of the obvious liquid carried by boiling and splashing is treated, and the load of the subsequent wire mesh is reduced; the steam after passing through the baffle plates 332 reaches the wire mesh demisting part 34, the small liquid droplets are captured, coalesced and finally separated by the wire mesh demisting part 34 through the mechanisms of inertial collision, direct interception and Brownian diffusion, and most of the liquid water is removed before the steam leaves the separation chamber body, the steam dryness is greatly improved, the wire mesh demisting part 34 is usually called a wire mesh demister or a wire mesh mist eliminator, and belongs to mature prior art, which will not be described here; the steam after passing through the wire mesh demisting part 34 is discharged from the shell one 31 and enters the cyclone separator 4 for gas-liquid separation, and the terminal separation of the liquid droplets with a density greater than the steam is performed through the cyclone separator 4; a three-stage separation scheme from coarse to fine is constructed, and liquid droplets with different physical properties can be captured; the liquid carrying amount of the secondary steam can be greatly reduced, and the core equipment is directly protected; for the wastewater with complex composition or certain fluctuation in treatment capacity, the application provides higher safety margin and operation flexibility; the separated steam enters the compressor 5, the compressor 5 compresses the steam, and then inputs the steam into the falling film evaporation part 1 to perform heat exchange and evaporation treatment on the wastewater.

[0046] As shown in Figures 4-6 The hollow ring body 331 is fixedly connected with a plurality of pipelines 333 on the inner wall, and the pipelines 333 are located between the bending parts of adjacent two baffle plates 332, a plurality of nozzles one 336 are fixedly connected outside the pipelines 333, the hollow ring body 331 is fixedly connected with a liquid inlet one 334 at the lower end, and flow channels one and two are arranged in the hollow ring body 331, the flow channels one are communicated with the pipelines 333, and the input ends of the flow channels one are connected with the liquid inlet one 334.

[0047] The outer surface of the plurality of baffle plates 332 is provided with a liquid discharge port one 335, and the interior of the plurality of baffle plates 332 is provided with a flow channel three in communication with the liquid discharge port one 335. The flow channel three in the interior of the baffle plate 332 is in communication with the flow channel two in the interior of the hollow ring body 331. The lower end of the hollow ring body 331 is fixedly connected with a liquid discharge portion 337, and the output end of the flow channel two is connected with the liquid discharge portion 337.

[0048] The outer surface of the shell one 31 is provided with a reserved port 32, and the lower end of the shell one 31 is provided with a liquid discharge port two 35.

[0049] By adopting the above technical scheme, two pipeline total interfaces can be installed in the reserved port 32. The two pipeline total interfaces are connected with the liquid discharge port two 35 and the liquid inlet portion one 334 through two shunt pipelines, respectively. One pipeline total interface is used for discharging the liquid discharged from the liquid discharge portion 337, and the other pipeline total interface is used for feeding liquid into the liquid inlet portion one 334. The two pipeline total interfaces are sealed with the reserved port 32. The pipeline total interface is equivalent to a flow combining or shunting piece, which belongs to a common technology of liquid conveying. The two pipeline total interfaces are not shown in the drawings of the specification of the application. In the application, the improvement point is not how to design the infusion pipeline, but to avoid the deposition of salt in the baffle area of the baffle plate 332. Therefore, the pipeline design for liquid supply or discharge is not described in detail here. The liquid in the liquid inlet portion one 334 enters the pipeline 333 through the flow channel one and is discharged from the spray head one 336. The continuous liquid film flowing downward is formed on the surface of the bending part of the baffle plate 332 by the continuous spraying of the spray head one 336. When the salt-containing mist droplets in the steam hit the liquid film, they are immediately dissolved or washed away, avoiding the deposition and hardening of salt on the baffle plate 332. The salt flows along the outer surface of the baffle plate 332 together with the washing water and enters the liquid discharge port one 335. The washing water in the liquid discharge port one 335 enters the liquid discharge portion 337 through the flow channel two and the flow channel three. The liquid is discharged from the liquid discharge portion 337. The mist removal portion 33 has a preliminary online self-cleaning capability, which can prolong the operation cycle of the equipment. At the same time, the spraying water has a certain cooling effect on the baffle plate 332, which can avoid the local overheating of the baffle plate 332 caused by long-term contact with high-temperature steam, and is beneficial to the long-term stable use of the equipment material.

[0050] As shown in Figure 3 , Figure 7 and Figure 8 , the inner wall of the shell one 31 is further connected with a flow equalizing portion 36. The flow equalizing portion 36 includes a plate body 361 fixedly connected to the inner wall of the shell one 31 and a plurality of through holes 362 provided in the interior of the plate body 361.

[0051] The plate body 361 is integrally formed with a plurality of hollow annular flanges 363 at the upper end, and the inner wall of the hollow annular flange 363 is provided with an annular liquid distribution groove 365, the upper end of the hollow annular flange 363 is fixedly connected with a liquid inlet part two 364, and the inside of the hollow annular flange 363 is provided with a flow channel four in communication with the liquid inlet part two 364 and the annular liquid distribution groove 365.

[0052] By adopting the above technical scheme, the steam entering the shell one 31 rises first and contacts the plate body 361, and the steam can be rectified through the plurality of through holes 362, the steam is forced to pass through these through holes 362, forming fine steam columns with more uniform speed distribution; ideal gas inlet conditions are created for the baffle plate 332, improving its separation efficiency; the liquid inlet part two 364 is also connected with the pipeline of the above-mentioned pipeline total interface, the washing water enters the flow channel four and is discharged from the annular liquid distribution groove 365, the discharged liquid can form a downward flowing liquid film along the inner wall of the through hole 362, when the steam carrying salt-containing liquid droplets passes through the hole, the liquid droplets impact the wet hole wall under the action of inertia, are captured, dissolved and taken away by the liquid film; a part of the salt-containing liquid droplets can be removed, significantly reducing the pollutant load in the subsequent baffle plate 332 area; after the pre-washing of the flow uniformizing plate, the steam reaching the baffle plate 332 has greatly reduced liquid content and salt content, reducing the separation pressure and scaling risk of the baffle plate 332.

[0053] As shown in Figure 4 and Figure 6 It also includes an axial cyclone demisting part 6 connecting the exhaust end of the cyclone separator 4 with the input end of the compressor 5, and the axial cyclone demisting part 6 includes a shell two 61 connected with the exhaust end of the cyclone separator 4 and the input end of the compressor 5 at both ends, a hollow cyclone ring 62 fixedly connected inside the shell two 61, an inlet end 621 and a diffusion end 623 opened inside the hollow cyclone ring 62, a throat 622 opened inside the hollow cyclone ring 62 to communicate the inlet end 621 and the diffusion end 623, cyclone blades 624 fixedly connected on the inner wall of the throat 622, a plurality of liquid collecting cavities 625 opened on the inner wall of the throat 622, a liquid blocking weir 626 integrally formed on the inner wall of the throat 622, a liquid collecting groove 627 opened in the hollow cyclone ring 62 and communicating with the plurality of liquid collecting cavities 625, a vortex flow preventing baffle 630 fixedly connected on the inner wall of the liquid collecting groove 627, an exhaust pipeline 628 and a liquid discharge pipeline 629, one end of which penetrates the shell two 61 into the inside of the hollow cyclone ring 62 and communicates with the liquid collecting groove 627.

[0054] The inner wall of the shell two 61 is also fixedly connected with a horizontal flow flange 63, and the horizontal flow flange 63 is located below the hollow cyclone ring 62; the inside of the shell two 61 is fixedly connected with a liquid supply pipeline 64, and one end of the liquid supply pipeline 64 extending into the inside of the shell two 61 is fixedly connected with a nozzle two 65, and the other end of the liquid supply pipeline 64 penetrates the shell two 61 and extends outward.

[0055] By adopting the above technical scheme, after the steam is discharged, the steam reenters the compressor 5 through the shell 261, when the steam passes through the hollow cyclone ring 62, the differential pressure of the suction section of the compressor 5 is utilized to accelerate the steam at the throat 622, and the high-speed axial flow is forced to be converted into strong rotational flow through the cyclone vane 624, so that the kinetic energy of the steam is efficiently converted into rotational energy; the strong centrifugal force generated by rotation throws the trace amount of liquid droplets and particulate matters in the steam to the wall surface of the throat 622, and forms a liquid film flowing in a downward spiral, the liquid film is forced to separate from the wall surface mainstream at this position and enter the liquid collection groove 627 through the liquid blocking weir 626; the mist liquid droplets that still escape after the previous multi-stage separation are captured; the vortex flow in the liquid collection groove 627 can be avoided through the vortex flow blocking plate 630, so that the liquid in the liquid collection groove 627 is prevented from returning from the liquid collection groove 627; the gas in the liquid collection groove 627 can be discharged through the gas discharge pipeline 628, and the liquid in the liquid collection groove 627 can be discharged through the liquid discharge pipeline 629; when the gas passes through the hollow cyclone ring 62 and reaches the uniform flow flange 63, the tangential rotation of the internal airflow is inhibited through the uniform flow flange 63, the gas discharged from the hollow cyclone ring 62 is rectified to be axially into the compressor 5; at the same time, the condensed water can be supplied to the second nozzle 65 through the liquid supply pipeline 64 and sprayed out from the second nozzle 65, the extremely fine liquid droplets sprayed into the compressor 5 can keep a thin liquid film on the surface of the blade of the compressor 5, so that even if a trace amount of salt-containing mist enters, the liquid film can dilute the salt-containing mist and throw it out by centrifugal force, and the salt-containing mist cannot be dried and hardened on the blade; the liquid supply pipeline 64 and the second nozzle 65 can be installed and selected according to the system requirements.

[0056] Method for use:

[0057] Step 1, the wastewater enters the liquid supply pipeline 21 from the raw water inlet 22, the circulating pump 2 sends the wastewater into the falling film evaporation part 1 through the liquid supply pipeline 21, the steam enters the falling film evaporation part 1 and exchanges heat with the wastewater, the wastewater is heated and steam is generated; the generated steam enters the shell 131 through the air passage 12;

[0058] Step 2, the steam enters the shell 131 first contacts the plate body 361, and passes through the through hole 362 to reach the baffle demisting part 33, passes through between a plurality of baffle plates 332 and reaches the wire mesh demisting part 34, and is discharged from the shell 131 after passing through the wire mesh demisting part 34 to enter the cyclone separator 4 for gas-liquid separation;

[0059] Step 3, the separated steam enters the shell 261, when the steam passes through the throat 622, it is guided by the cyclone vane 624 and generates cyclone at the throat 622, the cyclone makes the liquid droplets in the gas form a liquid film on the inner wall of the throat 622 and flow, the liquid blocking weir 626 forces the liquid film to separate from the wall surface mainstream at this position and enter the liquid collection groove 627; the gas discharged from the hollow cyclone ring 62 is rectified to be axially into the compressor 5 through the uniform flow flange 63;

[0060] Step 4, the steam compressed by the compressor 5 is input into the falling film evaporation section 1 to perform heat exchange evaporation treatment on the wastewater.

[0061] The above merely provides the preferred embodiment of the present application; however, the protection scope of the present application is not limited thereto. Any person skilled in the art, within the technical range disclosed by the present application, according to the technical solution and the improvement concept of the present application, makes equivalent replacement or change, should be covered within the protection scope of the present application.

Claims

1. An MVR evaporator crystallizer suitable for high-salinity wastewater, comprising a falling film evaporation section (1), a circulating pump (2), a separation section (3), and a compressor (5), characterized in that: The discharge end of the falling film evaporator (1) is connected to the input end of the circulation pump (2) through the return pipe (11), and the output end of the circulation pump (2) is connected to the inlet end of the falling film evaporator (1) through the liquid delivery pipe (21); the falling film evaporator (1) is connected to the separation section (3) through the ventilation pipe (12) and the guide pipe (13), the exhaust end of the separation section (3) is connected to the input end of the cyclone separator (4), the exhaust end of the cyclone separator (4) is connected to the input end of the compressor (5), and the output end of the compressor (5) is connected to the air inlet end of the falling film evaporator (1); The separation section (3) includes a housing (31), a baffle demister (33) fixed on the inner wall of the housing (31), and a wire mesh demister (34). The wire mesh demister (34) is located above the baffle demister (33). The baffle demister (33) includes a hollow ring (331) fixed on the inner wall of the housing (31) and a plurality of baffles (332) fixed on the inner wall of the hollow ring (331). The hollow ring (331) has multiple pipes (333) fixed to its inner wall, and the pipes (333) are located between the bends of two adjacent baffles (332). Multiple nozzles (336) are fixed to the outside of the multiple pipes (333). The lower end of the hollow ring (331) has a liquid inlet (334) fixed to it. The hollow ring (331) has a flow channel and a flow channel, and the flow channel is connected to the multiple pipes (333). The input end of the flow channel is connected to the liquid inlet (334). The outer surface of the plurality of baffles (332) is provided with a drain port (335), and the interior of the plurality of baffles (332) is provided with a flow channel (335) that is connected to the drain port (335). The flow channel (332) inside the baffles (332) is connected to the flow channel (2) inside the hollow ring (331). The lower end of the hollow ring (331) is fixedly connected to a drain section (337), and the output end of the flow channel (2) is connected to the drain section (337).

2. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 1, characterized in that: The outer surface of the first shell (31) is provided with a reserved opening (32), and the lower end of the first shell (31) is provided with a drain outlet (35).

3. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 2, characterized in that: The inner wall of the housing (31) is also connected to a flow equalization section (36), and the flow equalization section (36) includes a plate (361) fixed to the inner wall of the housing (31) and a plurality of through holes (362) opened inside the plate (361).

4. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 3, characterized in that: The upper end of the plate (361) is integrally formed with multiple hollow annular flanges (363), and the inner wall of the hollow annular flanges (363) is provided with an annular liquid distribution groove (365). The upper end of the hollow annular flanges (363) is fixedly connected with a liquid inlet part two (364), and the hollow annular flanges (363) are provided with a flow channel four that communicates with the liquid inlet part two (364) and the annular liquid distribution groove (365).

5. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 4, characterized in that: It also includes an axial cyclone demister (6) that connects the exhaust end of the cyclone separator (4) to the input end of the compressor (5), and the axial cyclone demister (6) includes a housing two (61) whose two ends are respectively connected to the exhaust end of the cyclone separator (4) and the input end of the compressor (5), a hollow cyclone ring (62) fixed inside the housing two (61), an inlet end (621) and a diffuser end (623) opened inside the hollow cyclone ring (62), and a throat (622) opened inside the hollow cyclone ring (62) that connects the inlet end (621) and the diffuser end (623). Swirl blades (624) attached to the inner wall of the throat (622), multiple liquid collection chambers (625) opened on the inner wall of the throat (622), a liquid-blocking weir (626) integrally formed on the inner wall of the throat (622), a liquid collection trough (627) opened in the hollow swirling ring (62) and connected to the multiple liquid collection chambers (625), an anti-vortex baffle (630) fixed to the inner wall of the liquid collection trough (627), an exhaust pipe (628) and a drain pipe (629) that penetrate the second shell (61) into the hollow swirling ring (62) and are connected to the liquid collection trough (627).

6. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 5, characterized in that: The inner wall of the second housing (61) is also fixedly connected to a flow flange (63), and the flow flange (63) is located below the hollow vortex ring (62); a liquid supply pipe (64) is fixedly connected inside the second housing (61), and a nozzle (65) is fixedly connected to one end of the liquid supply pipe (64) that extends into the second housing (61), and the other end of the liquid supply pipe (64) passes through the second housing (61) and extends outward.

7. The MVR evaporator crystallizer suitable for high-salinity wastewater according to claim 6, characterized in that: The falling film evaporation section (1) is provided with an exhaust port (15) and a condensate outlet (16) on the outside. The return pipe (11) is provided with a drain outlet (14), and the liquid delivery pipe (21) is provided with a raw water inlet (22).

8. A method of using an MVR evaporator crystallizer suitable for high-salinity wastewater, characterized in that: The MVR evaporator crystallizer for high-salinity wastewater as described in claim 7 comprises the following steps: Step 1: Wastewater enters the liquid delivery pipeline (21) from the raw water inlet (22). The circulating pump (2) sends the wastewater into the falling film evaporator (1) through the liquid delivery pipeline (21). Steam enters the falling film evaporator (1) and exchanges heat with the wastewater to heat the wastewater and generate steam. The generated steam enters the shell (31) through the ventilation pipeline (12). Step 2: Steam enters the first shell (31) and first contacts the plate (361), and passes through the through hole (362) to reach the baffle demister (33). It passes through the multiple baffles (332) and reaches the wire mesh demister (34). After passing through the wire mesh demister (34), it is discharged from the first shell (31) and enters the cyclone separator (4) for gas-liquid separation. Step 3: The separated steam enters the second shell (61). When the steam passes through the throat (622), it is guided by the swirl vanes (624) and generates a swirling flow in the throat (622). The swirling flow causes the liquid droplets in the gas to form a liquid film on the inner wall of the throat (622) and flow. The liquid-blocking weir (626) forces the liquid film to detach from the main flow on the wall and enter the liquid collection tank (627). The gas discharged from the hollow swirl ring (62) is rectified by the horizontal flow flange (63) so that it enters the compressor (5) axially. Step 4: The compressor (5) compresses the steam and then inputs it into the falling film evaporator (1) to perform heat exchange and evaporation treatment on the wastewater.

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