Falling film demisting and gas washing device

Abstract

The utility model discloses a falling film demisting and gas washing device which comprises a steam treatment part and a gas washing part, the folded plate demister comprises a shell and a #-shaped distribution plate, the shell comprises a first inner cavity, one end of the first inner cavity is communicated with the steam treatment part, and the other end of the first inner cavity is used for being communicated with an external steam compressor; the defoaming part comprises a plurality of baffle plates and a plurality of trapping hooks, each baffle plate comprises a plurality of peak parts, every two adjacent peak parts face the same direction in the second direction, every two adjacent peak parts face different directions in the first direction, each trapping hook comprises a connecting part and a hook part which are connected, and the hook parts and the corresponding peak parts are arranged at intervals in the second direction; the projections of the hook parts and the corresponding peak parts coincide; and external secondary steam can sequentially flow through the external falling film evaporator, the steam treatment part, the #-shaped distribution plate, the defoaming part and the external steam compressor. According to the steam compressor, entrainment carried in secondary steam can be reduced, and the influence on the efficiency of the steam compressor and the dynamic balance of the impeller is reduced.

Description

Technical Field

[0001] The utility model relates to the field of falling film demisting and gas washing devices, and particularly relates to a falling film demisting and gas washing device. Background Art

[0002] The secondary steam evaporated by a falling film evaporator will be subjected to gas washing and demisting in an MVR (Mechanical Vapor Recompression) falling film evaporation system to improve the quality of the secondary steam. The MVR falling film evaporation system consists of a falling film evaporator, an MVR falling film demisting and gas washing device, a steam compressor, a falling film circulation pump, a falling film discharging pump, and material pipelines, steam pipelines, condensate pipelines and other auxiliary facilities.

[0003] The current MVR falling film demisting and gas washing device generally consists of a gas-liquid separator and a primary wire mesh demister built inside the gas-liquid separator. The secondary steam evaporated from the material carries entrained material droplets, so it first enters the gas-liquid separator and undergoes preliminary gas-liquid separation in the gas phase space. The secondary steam then passes through the primary wire mesh demister to further remove the entrained small droplets. Finally, after the secondary steam exits the gas-liquid separator, it enters the MVR steam compressor through the secondary steam pipeline. The secondary steam is heated, pressurized and cooled in the MVR steam compressor, and then enters the shell side of the falling film evaporator as heating steam. After releasing the latent heat to heat the material, the heating steam condenses into condensate, which is collected and discharged for secondary utilization.

[0004] There are generally index requirements for the discharged condensate. If there is too much entrainment of secondary steam mist, it will cause the indexes such as the conductivity and ions of the condensate to exceed the standard. When the secondary steam passes through the steam compressor, it is easy to corrode the impeller inside the steam compressor. Moreover, if there is too much entrainment of secondary steam mist, after being compressed by the steam compressor, the secondary steam changes from saturated steam to superheated steam, and the entrained liquid droplets will evaporate, concentrate and crystallize as the steam superheats. These crystals will adhere to the impeller and volute of the steam compressor, affecting the compressor efficiency and even the dynamic balance of the impeller. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the technical problem that too much entrainment of secondary steam mist affects the efficiency of the steam compressor and the dynamic balance of the impeller. The utility model provides a falling film demisting and gas washing device, which can reduce the entrained mist in the secondary steam and reduce the influence on the efficiency of the steam compressor and the dynamic balance of the impeller.

[0006] To solve the above technical problem, an embodiment of the utility model discloses a falling film demisting and gas washing device, comprising:

[0007] A steam treatment unit, into which the secondary steam from the outside can flow from a falling film evaporator outside.

[0008] Baffle demister, the baffle demister includes a housing and a cross-shaped distribution plate, the housing includes a first inner cavity, the cross-shaped distribution plate is arranged in the first inner cavity, along a first direction, one end of the first inner cavity is communicated with the steam treatment part, and the other end of the first inner cavity is used for communicating with an external steam compressor;

[0009] Demisting part, the demisting part is arranged in the first inner cavity, along the first direction, the demisting part is arranged at an interval from the cross-shaped distribution plate; the demisting part includes a plurality of baffle plates and a plurality of trapping hooks, along a second direction, the plurality of baffle plates are arranged at intervals, each baffle plate includes a plurality of peak parts, along the second direction, the peak parts of two adjacent baffle plates face the same direction, along the first direction, the peak parts of two adjacent baffle plates of each baffle plate face different directions, each trapping hook corresponds to each peak part, each trapping hook includes a connected connecting part and a hook part, the connecting part is connected to the corresponding peak part, along the second direction, the hook part is arranged at an interval from the corresponding peak part, in the second direction, the projection of the hook part coincides with the corresponding peak part, the second direction is perpendicular to the first direction; wherein,

[0010] The secondary steam from the outside can flow through the falling film evaporator outside, the steam treatment part, the cross-shaped distribution plate, the demisting part and the steam compressor outside in sequence.

[0011] Adopting the above technical solution, the secondary steam tangentially enters the steam treatment part from the outside falling film evaporator, and the secondary steam realizes the first stage of mist separation.

[0012] The secondary steam after the first stage of mist separation enters the first inner cavity of the baffle demister, and will first pass through the cross-shaped distribution plate, ensuring that the secondary steam can reduce its speed and evenly fill the first inner cavity, so as to be evenly distributed to the baffle plates, improving the demisting ability of the demisting part.

[0013] The demisting part included in the falling film demisting and gas washing device can be multiple. Taking the falling film demisting and gas washing device including two demisting parts as an example. The secondary steam evenly dispersed by the cross-shaped distribution plate first flows through the first demisting part to realize the second stage of mist separation. When the secondary steam passes through the peak part of the baffle plate of the first demisting part, the liquid droplets will hit the hook part of the trapping hook corresponding to the peak part, and thus be trapped by the hook part. Subsequently, under the action of gravity, the liquid droplets trapped by the trapping hook flow down along the baffle plate of the first demisting part.

[0014] Subsequently, the secondary steam passing through the first demisting section will pass through the second demisting section to achieve three - stage mist separation. Similarly, when the secondary steam passes through the peak of the baffle plate of the second demisting section, the liquid droplets will hit the hook part of the trapping hook corresponding to the peak, and thus be trapped by the hook part. Subsequently, under the action of gravity, the liquid droplets trapped by the trapping hook flow downward along the baffle plate of the second demisting section. The secondary steam passing through the second demisting section leaves the baffle demister and enters the steam compressor.

[0015] In the technical solution of the present invention, the secondary steam will sequentially pass through the steam treatment section to achieve primary mist separation, pass through the first demisting section to achieve secondary mist separation, and pass through the second demisting section group to achieve three - stage mist separation. Compared with the prior art in which the secondary steam only passes through a vapor - liquid separator and a primary wire - mesh demister, the number of mist separation times is more, which can effectively reduce the mist entrained in the secondary steam and reduce the impact on the efficiency of the steam compressor and the dynamic balance of the impeller.

[0016] In addition, since the steam treatment section and the baffle demister are adopted in the technical solution of the present invention to replace the huge vapor - liquid separator in the prior art, on the premise of ensuring the demisting efficiency, the equipment diameter is greatly reduced, the investment cost is reduced, and the floor area is decreased.

[0017] According to another specific embodiment of the present invention, the cross - shaped distribution plate includes a first distribution plate and a second distribution plate. The first distribution plate and the second distribution plate respectively extend along the second direction. Along the third direction, the first distribution plate and the second distribution plate are arranged at intervals. The first distribution plate includes a first surface, and the second distribution plate includes a second surface. Along the third direction, the first surface and the second surface are arranged opposite to each other. The distance between the first surface and the second surface increases along the first direction towards the demisting section. The third direction is perpendicular to the first direction.

[0018] The cross - shaped distribution plate further includes a third distribution plate and a fourth distribution plate. The third distribution plate and the fourth distribution plate respectively extend along the third direction. Along the second direction, the third distribution plate and the fourth distribution plate are arranged at intervals. The third distribution plate is connected to the first distribution plate and the second distribution plate, and the fourth distribution plate is connected to the first distribution plate and the second distribution plate. The third distribution plate includes a third surface, and the fourth distribution plate includes a fourth surface. Along the second direction, the third surface and the fourth surface are arranged opposite to each other. The distance between the third surface and the fourth surface increases along the first direction towards the demisting section.

[0019] Adopting the above - mentioned technical solution, when the secondary steam after primary mist separation enters the baffle demister, since the inlet is small, the secondary steam at this time is relatively concentrated. Therefore, the cross - shaped distribution plate is provided to make the relatively concentrated secondary steam evenly fill the first inner cavity.

[0020] Since the distance between the first surface and the second surface increases towards the demisting part in the first direction, when the secondary steam passes through the grid distribution plate, it will spread along the first surface and the second surface towards the demisting part. Similarly, since the distance between the third surface and the fourth surface increases towards the demisting part in the first direction, when the secondary steam passes through the grid distribution plate, it will spread along the third surface and the fourth surface towards the demisting part, ensuring that the secondary steam uniformly fills the first inner cavity.

[0021] According to another specific embodiment of the present invention, along the second direction, the projection of each hook part covers the projection of the corresponding peak part.

[0022] By adopting the above technical solution, the projection of each hook part covers the projection of the corresponding peak part, ensuring that along the second direction, each hook part and its corresponding peak part can be correspondingly arranged. In this way, the liquid droplets captured by the capture hooks can flow down along the baffle plate instead of returning to the air and causing secondary or tertiary mist separation failure.

[0023] According to another specific embodiment of the present invention, the steam treatment part includes a cyclone separator. The cyclone separator includes a central gas pipe and a first inner wall. The central gas pipe includes a first outer wall. The first inner wall and the first outer wall define a liquid guiding channel. The falling film demisting and gas washing device includes a demister water tank. The demister water tank is respectively communicated with the liquid guiding channel and the first inner cavity. The central gas pipe is communicated with the first inner cavity. The demister water tank is used for collecting the liquid droplets separated from the secondary steam flowing through the liquid guiding channel and the first inner cavity from the outside.

[0024] By adopting the above technical solution, the secondary steam tangentially enters the cyclone separator from the falling film evaporator outside. The secondary steam tangentially rotates and rises to achieve primary mist separation. The liquid droplets flow downward by gravity into the liquid guiding channel and then flow into the demister water tank. The secondary steam after primary mist separation enters the first inner cavity of the baffle demister from the central gas pipe. The secondary steam passes through the first inner cavity to achieve secondary and tertiary mist separation, and the liquid droplets flowing down are collected by the demister water tank.

[0025] According to another specific embodiment of the present invention, the baffle demister includes a liquid level gauge and a drainage pump. The liquid level gauge is electrically connected to the drainage pump and the demister water tank respectively. The liquid level gauge is used for detecting the liquid droplet height in the demister water tank. The drainage pump is used to start when the liquid droplet height is higher than the middle position height of the demister water tank and close when the liquid droplet height is lower than the set height.

[0026] With the above technical solution, when the height of the liquid foam is higher than the height of the middle position of the demister water tank, there is no drainage pump to start draining the liquid foam, and excessive liquid foam accumulated subsequently may return to the first inner cavity, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is provided to detect the height of the liquid foam in the demister water tank so as to drain the excessive liquid foam in the demister water tank in time.

[0027] According to another specific embodiment of the present invention, the steam treatment part includes a spray scrubber, the falling film demisting scrubbing device includes a steam scrubbing circulation pump, one end of the steam scrubbing circulation pump is communicated with the spray scrubber, the other end of the steam scrubbing circulation pump is used to be communicated with an external acid adding pump, and one end of the first inner cavity is communicated with the spray scrubber;

[0028] The spray scrubber includes a second inner cavity and a plurality of spray heads, the plurality of spray heads are arranged in the second inner cavity, the second inner cavity is communicated with the first inner cavity, the plurality of spray heads are arranged at intervals along the second direction, the steam scrubbing circulation pump includes a steam scrubbing pipeline, the plurality of spray heads are respectively communicated with the steam scrubbing pipeline, the orientations of the plurality of spray heads are the same as the flow direction of the external secondary steam, the falling film demisting scrubbing device includes a demister water tank, the demister water tank is communicated with the second inner cavity and the first inner cavity respectively, and the demister water tank is used to collect the liquid foam separated from the external secondary steam flowing through the second inner cavity and the first inner cavity.

[0029] With the above technical solution, the secondary steam sometimes contains irritating gases such as ammonia. Therefore, a spray scrubber and a steam scrubbing circulation pump are provided, and the other end of the steam scrubbing circulation pump is communicated with an acid adding pump. The secondary steam enters the spray scrubber from an external falling film evaporator, and after being sprayed with acid-containing water ejected by the spray heads to absorb ammonia (i.e., spray scrubbing), primary mist separation is achieved, and the liquid foam and the spray water containing the reaction product of acid and ammonia flow downward by gravity into the demister water tank. The secondary steam after primary mist separation enters the first inner cavity of the baffle demister. The secondary steam passes through the first inner cavity to achieve secondary mist separation and tertiary mist separation, and the liquid foam flowing down is collected by the demister water tank.

[0030] According to another specific embodiment of the present invention, the falling film demisting scrubbing device further includes a liquid collecting member, the liquid collecting member is communicated with the first inner cavity, the second inner cavity and the demister water tank respectively, and the liquid collecting member is horizontally aligned with the baffle demister.

[0031] With the above technical solution, since the secondary steam after spray scrubbing will have a 90° turn before entering the demister, most of the spray water containing the reaction product of acid and ammonia will impact on the liquid collecting member due to inertia. If there is no liquid collecting member, the spray water containing the reaction product of acid and ammonia will directly impact on the baffle in the demister. In the long run, it will damage the baffle and affect the service life of the baffle.

[0032] According to another specific embodiment of the present invention, the demister includes a liquid level gauge, the washing steam circulation pump includes a sewage discharge pipeline, the liquid level gauge is electrically connected to the sewage discharge pipeline and the demister water tank respectively, the liquid level gauge is used to detect the liquid foam height in the demister water tank, the sewage discharge pipeline is used to start when the liquid foam height is higher than the middle position height of the demister water tank, and the sewage discharge pipeline is closed when the liquid foam height is lower than the set height;

[0033] The falling film demisting scrubbing device further includes a makeup water valve, the liquid level gauge is electrically connected to the makeup water valve and an external acid adding pump respectively, the demister water tank is communicated with the makeup water valve and the external acid adding pump respectively, and the makeup water valve is used to start the makeup water valve and the external acid adding pump respectively when the liquid foam height is lower than the set height.

[0034] With the above technical solution, before the secondary steam enters the spray scrubber, it is necessary to add condensed water to the demister water tank to the normal liquid level (for example, the height of the condensed water accounts for one-third of the height of the demister water tank), then start the acid adding pump to add dilute sulfuric acid to the set pH value (the pH value is, for example, 4-5), and then start the spray scrubber. If the pH value is too low, it is easy to corrode the demister water tank; if the pH value is too high, the condensed water in the demister water tank is alkaline and loses the function of absorbing ammonia gas.

[0035] During the operation of the spray scrubber, if the liquid foam height is higher than the middle position height of the demister water tank, the sewage discharge pipeline will start to discharge the liquid foam. If there is no sewage discharge pipeline to start discharging the liquid foam, too much liquid foam accumulated subsequently may return to the first inner cavity, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is set to detect the liquid foam height in the demister water tank so as to start the sewage discharge pipeline in time to discharge too much liquid foam in the demister water tank.

[0036] When the liquid foam height is lower than the set height (the set height is, for example, the liquid foam height accounts for one-fifth of the height of the demister water tank), the sewage discharge pipeline is closed, and the makeup water valve and the acid adding pump are started respectively, so that the condensed water in the demister water tank returns to the normal liquid level again and the pH value returns to the set value.

[0037] According to another specific embodiment of the present utility model, the folded-plate demister includes a pH meter, the pH meter is electrically connected to the sewage discharge pipeline, the pH meter is used to detect the pH value of the liquid foam in the demister water tank, and the sewage discharge pipeline is used to start when the pH value is greater than or equal to a set value.

[0038] With the above technical solution, if the pH is too high, the condensed water in the demister water tank is alkaline and loses the function of absorbing ammonia. Therefore, when the pH value of the liquid foam in the demister water tank is greater than or equal to the set value (the set value is, for example, pH = 6), the sewage discharge pipeline needs to be started to discharge the liquid foam in the demister water tank to make room for the subsequent condensed water and dilute sulfuric acid to enter.

[0039] According to another specific embodiment of the present utility model, the steam treatment part includes a spray scrubber, the falling film demisting scrubbing device includes a steam scrubbing circulation pump, the steam scrubbing circulation pump is communicated with the spray scrubber, and one end of the first inner cavity is communicated with the spray scrubber;

[0040] The spray scrubber includes a second inner cavity and a plurality of spray heads, the plurality of spray heads are arranged in the second inner cavity, the second inner cavity is communicated with the first inner cavity, the plurality of spray heads are arranged at intervals along the second direction, the steam scrubbing circulation pump includes a steam scrubbing pipeline, the plurality of spray heads are respectively communicated with the steam scrubbing pipeline, the orientations of the plurality of spray heads are the same as the flow direction of the secondary steam from the outside, the falling film demisting scrubbing device includes a demister water tank, the demister water tank is communicated with the second inner cavity and the first inner cavity respectively, and the demister water tank is used to collect the liquid foam separated from the secondary steam from the outside flowing through the second inner cavity and the first inner cavity.

[0041] With the above technical solution, sometimes when dealing with materials with relatively high foaming properties, there will be particularly many mist droplets entrained in the secondary steam. Therefore, a spray scrubber and a steam scrubbing circulation pump are provided. The secondary steam enters the spray scrubber from the falling film evaporator from the outside. After being sprayed by the condensed water ejected from the spray heads (i.e., spray scrubbing), most of the mist droplets will be carried away by the spray water, realizing primary mist separation. The mist droplets and the spray water flow downward by gravity into the demister water tank. The secondary steam after primary mist separation enters the first inner cavity of the folded-plate demister. The secondary steam realizes secondary mist separation and the mist droplets flowing down from the third mist separation in the first inner cavity are collected by the demister water tank.

[0042] According to another specific embodiment of the present utility model, the falling film demisting scrubbing device further includes a liquid collecting member, the liquid collecting member is communicated with the first inner cavity, the second inner cavity and the demister water tank respectively, and the liquid collecting member is horizontally aligned with the folded-plate demister.

[0043] With the above technical solution, since the secondary steam after spray scrubbing will have a 90° turn before entering the demister, most of the spray water will impact on the liquid collecting member due to inertia. If there is no liquid collecting member, the spray water will directly impact on the baffle in the demister. In the long run, it will damage the baffle and affect the service life of the baffle.

[0044] According to another specific embodiment of the present invention, the demister includes a liquid level gauge and a conductivity meter. The washing steam circulation pump includes a sewage discharge pipeline. The liquid level gauge is electrically connected to the sewage discharge pipeline and the demister water tank respectively. The liquid level gauge is used to detect the liquid foam height in the demister water tank. The sewage discharge pipeline is used to start when the liquid foam height is higher than the middle position height of the demister water tank. The conductivity meter is used to detect the conductivity value of the liquid foam in the demister water tank. The sewage discharge pipeline is used to start when the conductivity value is higher than the set value. When the liquid foam height is lower than the set height, the sewage discharge pipeline is closed.

[0045] The falling film demisting and washing device further includes a makeup water valve. The makeup water valve is electrically connected to the liquid level gauge and is communicated with the demister water tank. The makeup water valve is used to start when the liquid foam height is lower than the set height.

[0046] With the above technical solution, before the secondary steam enters the spray scrubber, it is necessary to add condensate water to the normal liquid level in the demister water tank (for example, the height of the condensate water accounts for one-third of the height of the demister water tank), and then start the spray scrubber.

[0047] During the operation of the spray scrubber, if the liquid foam height is higher than the middle position height of the demister water tank, or the conductivity value of the liquid foam in the demister water tank is higher than the set value (the set value is determined by the specific on-site situation, for example, it can be 5000 μs / cm), the sewage discharge pipeline will start to discharge the liquid foam. If there is no sewage discharge pipeline to start discharging the liquid foam, too much liquid foam accumulated subsequently may return to the first inner cavity, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is set to detect the liquid foam height in the demister water tank so as to start the sewage discharge pipeline in time to discharge the excessive liquid foam in the demister water tank.

[0048] When the liquid foam height is lower than the set height (the set height is, for example, the liquid foam height accounts for one-fifth of the height of the demister water tank), the sewage discharge pipeline is closed and the makeup water valve is started to make the condensate water in the demister water tank return to the normal liquid level again.

[0049] According to another specific embodiment of the present utility model, the baffle demister includes a spraying part, the spraying part includes a first water pipe and a nozzle, one end of the first water pipe is used to communicate with an external water pump, the other end of the first water pipe is communicated with the nozzle, the nozzle is arranged in the first inner cavity, and along the first direction, the nozzle faces the plurality of baffle plates.

[0050] With the above technical solution, since some entrained liquid droplets may adhere to the baffle plates when the secondary steam passes through the baffle plates, over time, the adjacent baffle plates may be blocked, affecting the demisting effect. Therefore, a spraying part is provided, and the nozzle sprays towards the baffle plates to wash away the liquid droplets adhering to the baffle plates. Description of the Drawings

[0051] Figure 1 Schematic diagram showing the falling film de-misting and scrubbing device in the first embodiment of the present utility model.

[0052] Figure 2 Schematic diagram showing the falling film de-misting and scrubbing device in the second embodiment of the present utility model.

[0053] Figure 3 Schematic diagram showing the falling film de-misting and scrubbing device in the third embodiment of the present utility model.

[0054] Figure 4 Top view showing the baffle demister in the embodiment of the present utility model.

[0055] Figure 5A Schematic diagram showing the demisting part in the embodiment of the present utility model.

[0056] Figure 5B Showing in the embodiment of the present utility model Figure 5A Partial enlarged view of area A.

[0057] Figure 6A Showing the three-dimensional view of the grid distribution plate in the embodiment of the present utility model Figure 1 .

[0058] Figure 6B Showing the three-dimensional view of the grid distribution plate in the embodiment of the present utility model Figure 2 .

[0059] Figure 7 Schematic diagram showing the cyclone separator in the embodiment of the present utility model.

[0060] Figure 8 Schematic diagram showing the spray scrubber in the embodiment of the present utility model.

[0061] Description of the Reference Numerals

[0062] Steam treatment unit 10;

[0063] Cyclone separator 11;

[0064] Central gas pipe 111; First outer wall 1111;

[0065] First inner wall 112;

[0066] Liquid guide channel 113;

[0067] Spray scrubber 12;

[0068] Second inner cavity 121; Spray head 122;

[0069] Baffle demister 20;

[0070] Outer shell 21; First inner cavity 211;

[0071] Cross-shaped distribution plate 22;

[0072] First distribution plate 221; First surface 2211;

[0073] Second distribution plate 222; Second surface 2221;

[0074] Third distribution plate 223; Third surface 2231;

[0075] Fourth distribution plate 224; Fourth surface 2241;

[0076] Through hole 225;

[0077] Drainage pump 23;

[0078] Spraying part 24;

[0079] First water pipe 241; Nozzle 242;

[0080] Demisting part 30;

[0081] Baffle 31; Peak part 311;

[0082] Collection hook 32; Connection part 321; Hook part 322;

[0083] Demister water tank 40;

[0084] Steam scrubbing circulation pump 50;

[0085] Steam scrubbing pipeline 51; Sewage discharge pipeline 52;

[0086] Liquid collecting part 60;

[0087] Make-up water valve 70;

[0088] Falling film evaporator 100;

[0089] Acid adding pump 200;

[0090] Water pump 300;

[0091] Steam compressor 400. Detailed implementation mode

[0092] The following specific embodiments illustrate the implementation mode of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Although the description of the present utility model will be introduced in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this implementation mode. On the contrary, the purpose of introducing the utility model in conjunction with the implementation mode is to cover other alternatives or modifications that may be extended based on the claims of the present utility model. In order to provide a deep understanding of the present utility model, many specific details will be included in the following description. The present utility model can also be implemented without these details. In addition, in order to avoid confusion or obscuring the key points of the present utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0093] It should be noted that in this specification, similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0094] In the description of this embodiment, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0095] Terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0096] In the description of this embodiment, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this embodiment can be understood according to specific situations.

[0097] To make the objectives, technical solutions, and advantages of the present utility model clearer, the following will further describe in detail the embodiments of the present utility model in conjunction with the accompanying drawings.

[0098] The secondary steam is obtained by evaporation from the material and entrained with material droplets. Depending on the amount of entrained material and the gas acidity and alkalinity in the secondary steam, there are three working conditions. The first is the conventional condition, that is, the entrained liquid droplets in the secondary steam are moderate and the entrained gas is neutral. The standard for moderate liquid droplets is: conduct a small-scale evaporation experiment on the material. If the conductivity of the condensed water ≤ 500 μS / cm, then the entrained liquid droplets in the secondary steam are moderate. The second is the ammonia-containing secondary steam condition, that is, the secondary steam is entrained with irritating gases such as ammonia. The third is the multi-liquid droplet secondary steam condition, that is, when encountering materials with relatively high foaming properties, the entrained mist droplets in the secondary steam will be particularly numerous. Generally, materials with relatively high foaming properties have the following properties: (1) The COD (Chemical Oxygen Demand) of the material ≥ 500 ppm; (2) The alkalinity of the material ≥ 1000 ppm; (3) The hardness of the material ≥ 500 ppm. As long as the material has any one of the above properties, it belongs to the material with relatively high foaming properties. The standard for particularly numerous entrained mist droplets is: conduct a small-scale evaporation experiment on the material. If the conductivity of the condensed water > 500 μS / cm, or a large number of bubbles can be seen in the material during the small-scale experiment, then the secondary steam is entrained with particularly numerous mist droplets.

[0099] Therefore, the present application provides a falling film demisting and gas washing device for the above three working conditions.

[0100] Reference Figures 1 to 3 , the present application provides a falling film demisting and gas washing device. The falling film demisting and gas washing device includes a steam treatment unit 10, a baffle demister 20, and two demisting units 30. The external secondary steam (not shown in the figure) can flow from the external falling film evaporator 100 into the steam treatment unit 10.

[0101] Reference Figure 1 and Figure 4 , the baffle demister 20 includes a housing 21 and a cross-shaped distribution plate 22. The housing 21 includes a first inner cavity 211, and the cross-shaped distribution plate 22 is arranged in the first inner cavity 211. Along the first direction X, one end of the first inner cavity 211 is communicated with the steam treatment unit 10, and the other end of the first inner cavity 211 is used to be communicated with the external steam compressor 400.

[0102] Reference Figures 4 to 5B, two demisting parts 30 are arranged in the first inner cavity 211. Along the first direction X, the first demisting part 30 is arranged at an interval from the cross-shaped distribution plate 22. Each demisting part 30 includes a plurality of baffle plates 31 and a plurality of trapping hooks 32. Along the second direction Y, the plurality of baffle plates 31 are arranged at intervals. Each baffle plate 31 includes three peak parts 311. Along the second direction Y, the peak parts 311 of two adjacent baffle plates 31 face the same direction. Along the first direction X, the adjacent two peak parts 311 of each baffle plate 31 face different directions.

[0103] Each trapping hook 32 corresponds to each peak part 311. Each trapping hook 32 includes a connecting part 321 and a hook part 322 which are connected. The connecting part 321 is connected to the corresponding peak part 311. Along the second direction Y, the hook part 322 is arranged at an interval from the corresponding peak part 311. In the second direction Y, the projections of the hook part 322 and the corresponding peak part 311 coincide. The second direction Y is perpendicular to the first direction X.

[0104] The secondary steam from the outside can flow through the falling film evaporator 100 outside, the steam treatment part 10, the cross-shaped distribution plate 22, the demisting part 30 and the steam compressor 400 outside in sequence.

[0105] Adopting the above technical solution, the secondary steam tangentially enters the steam treatment part 10 from the falling film evaporator 100 outside, and the secondary steam realizes primary mist separation.

[0106] The secondary steam after primary mist separation enters the first inner cavity 211 of the demisting plate 20 and will first pass through the cross-shaped distribution plate 22 to ensure that the secondary steam can reduce its speed and evenly fill the first inner cavity 211, so as to be evenly distributed to the baffle plates 31, improving the demisting ability of the demisting part 30.

[0107] The secondary steam evenly dispersed by the cross-shaped distribution plate 22 first flows through the first demisting part 30 to realize secondary mist separation. When the secondary steam passes through the peak part 311 of the baffle plate 31 of the first demisting part 30, the liquid droplets will hit the hook part 322 of the trapping hook 32 corresponding to the peak part 311, and thus be trapped by the hook part 322. Subsequently, under the action of gravity, the liquid droplets trapped by the trapping hook 32 flow downward along the baffle plate 31 of the first demisting part 30.

[0108] Subsequently, the secondary steam passing through the first demisting part 30 will pass through the second demisting part 30 to realize tertiary mist separation. Similarly, when the secondary steam passes through the peak part 311 of the baffle plate 31 of the second demisting part 30, the liquid droplets will hit the hook part 322 of the trapping hook 32 corresponding to the peak part 311, and thus be trapped by the hook part 322. Subsequently, under the action of gravity, the liquid droplets trapped by the trapping hook 32 flow downward along the baffle plate 31 of the second demisting part 30. The secondary steam passing through the second demisting part 30 leaves the demisting plate 20 and enters the steam compressor 400.

[0109] In this technical solution, the secondary steam will successively pass through the steam treatment unit 10 to achieve primary mist separation, pass through the first demisting unit 30 to achieve secondary mist separation, and pass through the second demisting unit 30 to achieve tertiary mist separation. Compared with the prior art where the secondary steam only passes through a vapor-liquid separator and a primary wire mesh demister, the number of mist separation times is more, which can effectively reduce the entrained mist in the secondary steam and reduce the impact on the efficiency of the steam compressor 400 and the impeller dynamic balance.

[0110] It should be noted that the number of demisting units 30 included in the falling film demisting and gas washing device is not specifically limited in the embodiments of the present application. For example, in other possible implementation manners, the number of demisting units 30 included in the falling film demisting and gas washing device may also be three, four, etc. The number of peak portions 311 included in each baffle 31 is not specifically limited in the embodiments of the present application. For example, in other possible implementation manners, the number of peak portions 311 included in each baffle 31 may also be two, four, etc.

[0111] In some possible implementation manners, referring to Figure 5A and 5B , along the second direction Y, the projection of each hook portion 322 covers the projection of the corresponding peak portion 311.

[0112] Adopting the above technical solution, the projection of each hook portion 322 covers the projection of the corresponding peak portion 311, ensuring that along the second direction Y, each hook portion 322 and its corresponding peak portion 311 can be correspondingly arranged. In this way, the liquid droplets captured by the trapping hook 32 can flow down along the baffle 31 instead of returning to the air and causing failure of secondary mist separation or tertiary mist separation.

[0113] In some possible implementation manners, referring to Figure 4 , Figure 6A and 6B , the grid distribution plate 22 includes a first distribution plate 221 and a second distribution plate 222, and the first distribution plate 221 and the second distribution plate 222 are respectively rectangular parallelepipeds. The first distribution plate 221 and the second distribution plate 222 respectively extend along the second direction Y, and along the third direction Z, the first distribution plate 221 and the second distribution plate 222 are spaced apart. The first distribution plate 221 includes a first surface 2211, and the second distribution plate 222 includes a second surface 2221. Along the third direction Z, the first surface 2211 and the second surface 2221 are oppositely arranged, and the distance between the first surface 2211 and the second surface 2221 increases along the first direction X towards the demisting unit 30, and the third direction Z is perpendicular to the first direction X.

[0114] The grid distribution plate 22 includes a third distribution plate 223 and a fourth distribution plate 224, and the third distribution plate 223 and the fourth distribution plate 224 are respectively cuboids. The third distribution plate 223 and the fourth distribution plate 224 respectively extend along the third direction Z. Along the second direction Y, the third distribution plate 223 and the fourth distribution plate 224 are arranged at intervals. The third distribution plate 223 is connected to the first distribution plate 221 and the second distribution plate 222, and the fourth distribution plate 224 is connected to the first distribution plate 221 and the second distribution plate 222. The third distribution plate 223 includes a third surface 2231, and the fourth distribution plate 224 includes a fourth surface 2241. Along the second direction Y, the third surface 2231 and the fourth surface 2241 are arranged opposite to each other, and the distance between the third surface 2231 and the fourth surface 2241 increases along the first direction X towards the demisting part 30.

[0115] The first distribution plate 221, the second distribution plate 222, the third distribution plate 223 and the fourth distribution plate 224 are respectively arranged in a crosswise manner to jointly enclose a square through hole 225, and the cross-sectional area of the through hole 225 gradually increases along the first direction X towards the demisting part 30, that is, the grid distribution plate 22 is in a "flared shape".

[0116] Adopting the above technical solution, when the secondary steam after the first stage of mist separation enters the corrugated demister 20, since the inlet is small, the secondary steam at this time is relatively concentrated. Therefore, the grid distribution plate 22 is provided so that the relatively concentrated secondary steam uniformly fills the first inner cavity 211.

[0117] Since the distance between the first surface 2211 and the second surface 2221 increases along the first direction X towards the demisting part 30, when the secondary steam passes through the grid distribution plate 22, it will spread along the first surface 2211 and the second surface 2221 towards the demisting part 30. Similarly, since the distance between the third surface 2231 and the fourth surface 2241 increases along the first direction X towards the demisting part 30, when the secondary steam passes through the grid distribution plate 22, it will spread along the third surface 2231 and the fourth surface 2241 towards the demisting part 30, ensuring that the secondary steam uniformly fills the first inner cavity 211.

[0118] It should be noted that the present application embodiment does not specifically limit the shapes of the first distribution plate 221, the second distribution plate 222, the third distribution plate 223 and the fourth distribution plate 224 respectively. For example, in other possible implementation manners, the shapes of the first distribution plate 221, the second distribution plate 222, the third distribution plate 223 and the fourth distribution plate 224 can be oval, wavy, and so on.

[0119] In some possible implementation manners, refer to Figure 1 and Figure 4, the baffle demister 20 includes a spraying part 24, and the spraying part 24 includes two groups of first water pipes 241 and nozzles 242. One end of the first water pipe 241 is used to communicate with an external water pump 300, the other end of the first water pipe 241 is communicated with the nozzle 242, the nozzle 242 is arranged in the first inner cavity 211, and along the first direction X, the nozzle 242 faces a plurality of baffle plates 31.

[0120] Adopting the above technical solution, since some entrained liquid droplets may adhere to the baffle plate 31 when the secondary steam passes through the baffle plate 31, over time, the adjacent baffle plates 31 will be blocked, affecting the defoaming effect. Therefore, the spraying part 24 is provided, and the nozzle 242 sprays towards the baffle plate 31 to wash away the liquid droplets adhering to the baffle plate 31.

[0121] It should be noted that the number of groups of the first water pipes 241 and nozzles 242 included in the spraying part 24 is not specifically limited in the embodiments of the present application. For example, in other possible implementation manners, the number of groups of the first water pipes 241 and nozzles 242 included in the spraying part 24 can be three groups, four groups, and so on.

[0122] Embodiment 1

[0123] On the basis of the above implementation manner, first, the falling film defogging and scrubbing device is introduced for processing conventional working conditions, that is, Embodiment 1.

[0124] In some possible implementation manners, referring to Figure 1 、 Figure 4 and Figure 7 , the steam treatment part 10 includes a cyclone separator 11, the cyclone separator 11 includes a central gas pipe 111 and a first inner wall 112, the central gas pipe 111 includes a first outer wall 1111, and the first inner wall 112 and the first outer wall 1111 define a liquid guiding channel 113. The falling film defogging and scrubbing device includes a demister water tank 40, the demister water tank 40 is respectively communicated with the liquid guiding channel 113 and the first inner cavity 211, and the central gas pipe 111 is communicated with the first inner cavity 211. The demister water tank 40 is used to collect the liquid droplets separated from the external secondary steam flowing through the liquid guiding channel 113 and the first inner cavity 211.

[0125] Adopting the above technical solution, the secondary steam tangentially enters the cyclone separator 11 from the external falling film evaporator 100, the secondary steam tangentially rotates and rises to achieve primary mist separation, and the liquid droplets flow downward by gravity into the liquid guiding channel 113 and then flow into the demister water tank 40. The secondary steam after primary mist separation enters the first inner cavity 211 of the baffle demister 20 from the central gas pipe 111. The secondary steam passes through the first inner cavity 211 to achieve secondary mist separation, and the liquid droplets flowing down during the three - time mist separation are collected by the demister water tank 40.

[0126] In some possible implementation manners, referring to Figure 1, the demister 20 includes a liquid level gauge (not shown in the figure) and a drain pump 23. The liquid level gauge is electrically connected to the drain pump 23 and the demister water tank 40 respectively. The liquid level gauge is used to detect the liquid foam height in the demister water tank 40. The drain pump 23 is used to start when the liquid foam height is higher than the middle position height of the demister water tank 40, and to close when the liquid foam height is lower than the set height.

[0127] With the above technical solution, if the drain pump 23 does not start to drain the liquid foam when the liquid foam height is higher than the middle position height of the demister water tank 40, too much accumulated liquid foam may return to the first inner cavity 211 later, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is set to detect the liquid foam height in the demister water tank 40 so as to drain the excessive liquid foam in the demister water tank 40 in time.

[0128] Next, the working principle of the falling film demisting and gas washing device in Embodiment 1 will be described in detail.

[0129] Refer to Figure 1 , Figures 4 to 7 , the secondary steam tangentially enters the cyclone separator 11. The secondary steam rotates tangentially and rises in the cyclone separator 11 to achieve primary mist separation. The liquid foam flows downward by gravity and enters the liquid guiding channel 113 and then flows into the demister water tank 40. The secondary steam after primary mist separation turns and enters the central gas pipe 111, and enters the first inner cavity 211 of the demister 20 from the central gas pipe 111.

[0130] The secondary steam entering the first inner cavity 211 will first pass through the "horn-shaped" grid distribution plate 22, and spread along the first surface 2211, the second surface 2221, the third surface 2231 and the fourth surface 2241 in the direction of the demisting part 30, ensuring that the secondary steam evenly fills the first inner cavity 211.

[0131] Subsequently, the secondary steam passes through two demisting parts 30 in sequence to achieve secondary mist separation and tertiary mist separation. When the secondary steam passes through the peak part 311 of the baffle plate 31 of the demisting part 30, the liquid foam will hit the hook part 322 of the trapping hook 32 corresponding to the peak part 311, and thus be trapped by the hook part 322. Subsequently, under the action of gravity, the liquid foam trapped by the trapping hook 32 flows downward along the baffle plate 31 and finally flows into the demister water tank 40. The secondary steam after tertiary mist separation flows into the steam compressor 400.

[0132] During the operation of the falling film demisting and gas washing device, the liquid level gauge will detect the liquid foam height in the demister water tank 40. When the liquid foam height is higher than the middle position height of the demister water tank 40, the drain pump 23 starts; when the liquid foam height is lower than the set height (for example, the set height is one-fifth of the height of the demister water tank 40), the drain pump 23 closes.

[0133] It should be noted that there is no specific limitation on the set height in the embodiments of the present application. For example, in other possible implementation manners, the set height can be one-fourth, one-sixth, etc. of the height of the liquid foam in the demister water tank 40, and the set height is determined by the specific on-site situation.

[0134] Embodiment 2

[0135] Next, the falling film demisting and scrubbing device is introduced for treating the ammonia-containing secondary steam condition, that is, Embodiment 2.

[0136] In some possible implementation manners, referring to Figure 2 、 Figure 4 and Figure 8 , the steam treatment unit 10 includes a spray scrubber 12, and the falling film demisting and scrubbing device includes a steam scrubbing circulation pump 50. One end of the steam scrubbing circulation pump 50 is communicated with the spray scrubber 12, the other end of the steam scrubbing circulation pump 50 is used to be communicated with an external acid adding pump 200, and one end of the first inner cavity 211 is communicated with the spray scrubber 12.

[0137] The spray scrubber 12 includes a second inner cavity 121 and three spray heads 122. The three spray heads 122 are arranged in the second inner cavity 121, and the second inner cavity 121 is communicated with the first inner cavity 211. The three spray heads 122 are arranged at intervals along the second direction Y. The steam scrubbing circulation pump 50 includes a steam scrubbing pipeline 51. The three spray heads 122 are respectively communicated with the steam scrubbing pipeline 51, and the orientations of the three spray heads 122 are the same as the flow direction of the external secondary steam. The demister water tank 40 is respectively communicated with the second inner cavity 121 and the first inner cavity 211, and the demister water tank 40 is used to collect the liquid foam separated from the external secondary steam flowing through the second inner cavity 121 and the first inner cavity 211.

[0138] With the above technical solution, the secondary steam sometimes contains irritating gases such as ammonia. Therefore, the spray scrubber 12 and the steam scrubbing circulation pump 50 are provided, and the other end of the steam scrubbing circulation pump 50 is communicated with the acid adding pump 200. The secondary steam enters the spray scrubber 12 from the external falling film evaporator 100. After being sprayed with the acid-containing water sprayed by the spray heads 122 and absorbing ammonia (i.e., spray scrubbing), the first-stage mist separation is realized, and the liquid foam and the spray water after the reaction of the acid and ammonia flow downward by gravity into the demister water tank 40. The secondary steam after the first-stage mist separation enters the first inner cavity 211 of the corrugated plate demister 20. The secondary steam realizes the second-stage mist separation and the third-stage mist separation in the first inner cavity 211, and the liquid foam flowing down is collected by the demister water tank 40.

[0139] It should be noted that there is no specific limitation on the number of the spray heads 122 in the embodiments of the present application. For example, in other possible implementation manners, the number of the spray heads 122 can be four, five, etc.

[0140] In some possible embodiments, referring to Figure 2 and Figure 4 , the falling film demisting and scrubbing device further includes a liquid collecting member 60. The liquid collecting member 60 is respectively communicated with the first inner cavity 211, the second inner cavity 121 and the demister water tank 40, and the liquid collecting member 60 is horizontally aligned with the corrugated plate demister 20.

[0141] With the above technical solution, since the secondary steam after spray scrubbing will have a 90° turn before entering the corrugated plate demister 20, most of the spray water after the reaction of acid and ammonia impacts on the liquid collecting member 60 due to inertia. If there is no liquid collecting member 60, the spray water after the reaction of acid and ammonia will directly impact on the baffle plate 31 in the corrugated plate demister 20. In the long run, it will cause damage to the baffle plate 31 and affect the service life of the baffle plate 31.

[0142] In some possible embodiments, referring to Figure 2 , the corrugated plate demister 20 includes a liquid level gauge (not shown in the figure). The steam washing circulation pump 50 includes a sewage discharge pipeline 52. The liquid level gauge is respectively electrically connected with the sewage discharge pipeline 52 and the demister water tank 40. The liquid level gauge is used to detect the liquid foam height in the demister water tank 40. The sewage discharge pipeline 52 is used to start when the liquid foam height is higher than the middle position height of the demister water tank 40, and the sewage discharge pipeline 52 is closed when the liquid foam height is lower than the set height.

[0143] The falling film demisting and scrubbing device further includes a water replenishing valve 70. The liquid level gauge is respectively electrically connected with the water replenishing valve 70 and the external acid adding pump 200. The demister water tank 40 is respectively communicated with the water replenishing valve 70 and the external acid adding pump 200. The water replenishing valve 70 is used to start the water replenishing valve 70 and the external acid adding pump 200 respectively when the liquid foam height is lower than the set height.

[0144] With the above technical solution, before the secondary steam enters the spray scrubber 12, it is necessary to add condensed water to the normal liquid level in the demister water tank 40 (the normal liquid level is, for example, the height of the condensed water accounts for one-third of the height of the demister water tank 40), and then start the acid adding pump 200 to add dilute sulfuric acid to the set pH value (the pH value is, for example, 4-5), and then start the spray scrubber 12. If the pH value is too low, it is easy to corrode the demister water tank 40; if the pH is too high, then the condensed water in the demister water tank 40 is alkaline and loses the function of absorbing ammonia gas.

[0145] During the operation of the spray scrubber 12, when the foam height is higher than the middle position height of the demister water tank 40, the sewage discharge pipe 52 will start to discharge the foam. If the sewage discharge pipe 52 does not start to discharge the foam, the excessive foam accumulated subsequently may return to the first inner cavity 211, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is provided to detect the foam height in the demister water tank 40, so as to start the sewage discharge pipe 52 in time to discharge the excessive foam in the demister water tank 40.

[0146] When the foam height is lower than the set height (the set height is, for example, one-fifth of the height of the demister water tank 40 occupied by the foam height), the sewage discharge pipe 52 is closed, and the water replenishing valve 70 and the acid adding pump 200 are started respectively, so that the condensed water in the demister water tank 40 returns to the normal liquid level again, and the pH value returns to the set value again.

[0147] It should be noted that the present application embodiment does not specifically limit the normal liquid level. For example, in other possible implementation manners, the normal liquid level can be one-half, one-fourth, etc. of the height of the demister water tank 40 occupied by the condensed water, and the normal liquid level is determined by the specific on-site situation. For the set height, the present application embodiment does not specifically limit it. For example, in other possible implementation manners, the set height can be one-fourth, one-sixth, etc. of the height of the demister water tank 40 occupied by the foam height, and the set height is determined by the specific on-site situation.

[0148] In some possible implementation manners, refer to Figure 2 , the baffle demister 20 includes a pH meter (not shown in the figure), the pH meter is electrically connected to the sewage discharge pipe 52, the pH meter is used to detect the pH value of the foam in the demister water tank 40, and the sewage discharge pipe 52 is used to start when the pH value is greater than or equal to the set value.

[0149] Adopting the above technical solution, if the pH is too high, then the condensed water in the demister water tank 40 is alkaline and loses the function of absorbing ammonia. Therefore, when the pH value of the foam in the demister water tank 40 is greater than or equal to the set value (the set value is, for example, pH = 6), the sewage discharge pipe 52 needs to be started to discharge the foam in the demister water tank 40, so as to leave space for the subsequent condensed water and dilute sulfuric acid to enter.

[0150] It should be noted that the present application embodiment does not specifically limit the set value of the pH value. For example, in other possible implementation manners, the set value of the pH value can be 5.5, 6.5, etc., and the set value of the pH value is determined by the specific on-site situation.

[0151] Next, the working principle of the falling film demisting scrubber in Embodiment 2 will be described in detail.

[0152] Refer to Figure 2 、Figures 4 to 8 Before the falling film demisting and scrubbing device is started, first add condensed water to the normal liquid level in the demister water tank 40 (the normal liquid level is, for example, the height of the condensed water accounting for one-third of the height of the demister water tank 40), then start the acid adding pump 200 to add dilute sulfuric acid to the set pH value, and then start the spray scrubber 12.

[0153] The secondary steam enters the spray scrubber 12 from the external falling film evaporator 100. After being sprayed with acid-containing water ejected by the spray head 122 and absorbing ammonia (i.e., spray scrubbing), primary mist separation is achieved. The liquid droplets and the spray water containing the reaction product of acid and ammonia flow downward by gravity, first hitting the liquid collecting member 60 and then entering the demister water tank 40. The secondary steam after the primary mist separation enters the first inner cavity 211 of the baffle demister 20.

[0154] The secondary steam entering the first inner cavity 211 first passes through the "horn-shaped" grid distribution plate 22, and diffuses along the first surface 2211, the second surface 2221, the third surface 2231 and the fourth surface 2241 towards the demisting part 30, ensuring that the secondary steam uniformly fills the first inner cavity 211.

[0155] Subsequently, the secondary steam successively passes through two demisting parts 30 to achieve secondary mist separation and tertiary mist separation. When the secondary steam passes through the peak part 311 of the baffle plate 31 of the demisting part 30, the liquid droplets will hit the hook part 322 of the trapping hook 32 corresponding to the peak part 311, and thus be trapped by the hook part 322. Subsequently, under the action of gravity, the liquid droplets trapped by the trapping hook 32 flow downward along the baffle plate 31 and finally flow into the demister water tank 40. The secondary steam after the tertiary mist separation flows into the steam compressor 400.

[0156] During the operation of the falling film demisting and scrubbing device, the liquid level gauge will detect the height of the liquid droplets in the demister water tank 40. When the height of the liquid droplets is higher than the middle position height of the demister water tank 40, the sewage discharge pipe 52 is started to discharge the liquid droplets. When the height of the liquid droplets is lower than the set height, the sewage discharge pipe 52 is closed, and the water replenishing valve 70 and the acid adding pump 200 are respectively started to make the condensed water in the demister water tank 40 return to the normal liquid level and the pH value return to the set value.

[0157] Embodiment III

[0158] Next, the falling film demisting and scrubbing device for treating the multi-droplet secondary steam condition, that is, Embodiment 3, will be introduced.

[0159] In some possible implementation manners, refer to Figure 3 , Figure 4 and Figure 8, the steam treatment unit 10 includes a spray scrubber 12, and the falling film demisting scrubbing device includes a steam scrubbing circulation pump 50. The steam scrubbing circulation pump 50 is communicated with the spray scrubber 12, and one end of the first inner cavity 211 is communicated with the spray scrubber 12.

[0160] The spray scrubber 12 includes a second inner cavity 121 and three spray heads 122. The three spray heads 122 are arranged in the second inner cavity 121, and the second inner cavity 121 is communicated with the first inner cavity 211. The three spray heads 122 are arranged at intervals along the second direction Y. The steam scrubbing circulation pump 50 includes a steam scrubbing pipeline 51. The three spray heads 122 are respectively communicated with the steam scrubbing pipeline 51, and the orientations of the three spray heads 122 are the same as the flow direction of the secondary steam from the outside. The demister water tank 40 is communicated with the second inner cavity 121 and the first inner cavity 211 respectively, and the demister water tank 40 is used for collecting the liquid droplets separated from the secondary steam from the outside flowing through the second inner cavity 121 and the first inner cavity 211.

[0161] With the above technical solution, sometimes when encountering materials with relatively high foaming properties, there will be particularly many mist droplets entrained in the secondary steam. Therefore, the spray scrubber 12 and the steam scrubbing circulation pump 50 are provided. The secondary steam enters the spray scrubber 12 from the falling film evaporator 100 from the outside. After being sprayed by the cold spray water ejected by the spray heads 122 (i.e., spray scrubbing), most of the liquid droplets will be carried away by the spray water, realizing primary mist separation. The liquid droplets and the spray water flow downward by gravity into the demister water tank 40. The secondary steam after primary mist separation enters the first inner cavity 211 of the corrugated plate demister 20. The secondary steam realizes secondary mist separation and tertiary mist separation in the first inner cavity 211, and the liquid droplets flowing down are collected by the demister water tank 40.

[0162] It should be noted that the number of the spray heads 122 is not specifically limited in the embodiments of the present application. For example, in other possible implementation manners, the number of the spray heads 122 can be four, five, etc.

[0163] In some possible implementation manners, referring to Figure 3 、 Figure 4 and Figure 8 , the falling film demisting scrubbing device further includes a liquid collecting member 60. The liquid collecting member 60 is communicated with the first inner cavity 211, the second inner cavity 121 and the demister water tank 40 respectively, and the liquid collecting member 60 is horizontally aligned with the corrugated plate demister 20.

[0164] With the above technical solution, since the secondary steam after spray scrubbing will have a 90° turn before entering the corrugated plate demister 20, most of the spray water impacts on the liquid collecting member 60 due to inertia. If there is no liquid collecting member 60, the spray water will directly impact on the baffle plate 31 in the corrugated plate demister 20. Over time, it will cause damage to the baffle plate 31 and affect the service life of the baffle plate 31.

[0165] In some possible embodiments, referring to Figure 3 , the demister 20 includes a liquid level gauge (not shown in the figure) and a conductivity meter (not shown in the figure). The washing steam circulation pump 50 includes a sewage discharge pipe 52. The liquid level gauge is electrically connected to the sewage discharge pipe 52 and the demister water tank 40 respectively. The liquid level gauge is used to detect the liquid foam height in the demister water tank 40. The sewage discharge pipe 52 is used to start when the liquid foam height is higher than the middle position height of the demister water tank 40 and close when the liquid foam height is lower than the set height. The conductivity meter is used to detect the conductivity value of the liquid foam in the demister water tank 40. The sewage discharge pipe 52 is used to start when the conductivity value is higher than the set value and close when the liquid foam height is lower than the set height.

[0166] The falling film demisting and gas washing device further includes a makeup water valve 70. The makeup water valve 70 is electrically connected to the liquid level gauge and communicates with the demister water tank 40. The makeup water valve 70 is used to start when the liquid foam height is lower than the set height.

[0167] Adopting the above technical solution, before the secondary steam enters the spray scrubber 12, it is necessary to add condensed water to the normal liquid level in the demister water tank 40 (the normal liquid level is, for example, the height of the condensed water accounting for one-third of the height of the demister water tank 40), and then start the spray scrubber 12.

[0168] During the operation of the spray scrubber 12, if the liquid foam height is higher than the middle position height of the demister water tank 40, or the conductivity value of the liquid foam in the demister water tank 40 is higher than the set value (the set value can be, for example, 5000 μs / cm), the sewage discharge pipe 52 will start to discharge the liquid foam. If there is no sewage discharge pipe 52 starting to discharge the liquid foam, excessive liquid foam accumulated subsequently may return to the first inner cavity 211, that is, return to the secondary steam, resulting in the failure of secondary mist separation and tertiary mist separation. Therefore, a liquid level gauge is set to detect the liquid foam height in the demister water tank 40 so as to start the sewage discharge pipe 52 in time to discharge the excessive liquid foam in the demister water tank 40.

[0169] When the liquid foam height is lower than the set height (the set height is, for example, the liquid foam height accounting for one-fifth of the height of the demister water tank 40), the sewage discharge pipe 52 is closed and the makeup water valve 70 is started to make the condensed water in the demister water tank 40 return to the normal liquid level again.

[0170] It should be noted that no specific restrictions are imposed on the normal liquid level in the embodiments of the present application. For example, in other possible embodiments, the normal liquid level can be one-half, one-fourth, etc. of the height of the condensate water in the demister water tank 40, and the normal liquid level is determined by the specific on-site conditions. No specific restrictions are imposed on the set height in the embodiments of the present application. For example, in other possible embodiments, the set height can be one-fourth, one-sixth, etc. of the height of the liquid foam in the demister water tank 40, and the set height is determined by the specific on-site conditions. No specific restrictions are imposed on the set value of the conductivity value in the embodiments of the present application. For example, in other possible embodiments, the set value of the conductivity value can be 4500 μs / cm, 4700 μs / cm, etc., and the set value of the conductivity value is determined by the specific on-site conditions.

[0171] Next, the working principle of the falling film demisting and scrubbing device in Embodiment 3 will be described in detail.

[0172] Refer to Figure 3 、 Figures 4 to 8 , before the falling film demisting and scrubbing device is started, first add condensate water to the normal liquid level (the normal liquid level is, for example, one-third of the height of the condensate water in the demister water tank 40) in the demister water tank 40, and then start the spray scrubber 12.

[0173] The secondary steam enters the spray scrubber 12 from the external falling film evaporator 100. After being sprayed by the cold spray water ejected by the spray head 122 (i.e., spray scrubbing), most of the liquid foam will be carried away by the spray water, realizing the first stage of mist separation. The spray water flows downward by gravity and first impacts on the liquid collecting member 60, and then enters the demister water tank 40. The secondary steam after the first stage of mist separation enters the first inner cavity 211 of the corrugated demister 20.

[0174] The secondary steam entering the first inner cavity 211 will first pass through the "horn-shaped" grid distribution plate 22, and spread along the first surface 2211, the second surface 2221, the third surface 2231 and the fourth surface 2241 towards the demisting part 30, ensuring that the secondary steam evenly fills the first inner cavity 211.

[0175] Subsequently, the secondary steam passes through two demisting parts 30 in sequence to achieve the second stage of mist separation and the third stage of mist separation. When the secondary steam passes through the peak part 311 of the baffle plate 31 of the demisting part 30, the liquid foam will hit the hook part 322 of the trapping hook 32 corresponding to the peak part 311, and thus be trapped by the hook part 322. Subsequently, under the action of gravity, the liquid foam trapped by the trapping hook 32 flows downward along the baffle plate 31 and finally flows into the demister water tank 40. The secondary steam after the third stage of mist separation flows into the steam compressor 400.

[0176] During the operation of the falling film demisting and scrubbing device, the liquid level gauge will detect the liquid foam height in the demister water tank 40, and the conductivity meter will detect the conductivity value of the liquid foam in the demister water tank 40. When the liquid foam height is higher than the middle position height of the demister water tank 40, or when the conductivity value of the liquid foam in the demister water tank 40 is higher than the set value (the set value can be, for example, 5000 μs / cm), the sewage discharge pipe 52 starts to discharge the liquid foam. When the liquid foam height is lower than the set height, the sewage discharge pipe 52 closes, and the water replenishing valve 70 starts, so that the condensate water in the demister water tank 40 returns to the normal liquid level again.

[0177] When it is necessary to switch the working conditions, for example, from the normal working condition to the ammonia-containing secondary steam working condition, only need to remove the cyclone separator 11 in Embodiment 1 and replace the cyclone separator 11 with the spray scrubber 12 in Embodiment 2. For example, when switching from the multi-liquid foam secondary steam working condition to the normal working condition, only need to remove the spray scrubber 12 in Embodiment 3 and replace the spray scrubber 12 with the cyclone separator 11 in Embodiment 1.

[0178] Although the present invention has been illustrated and described by referring to some preferred embodiments of the present invention, those of ordinary skill in the art should understand that the above content is a further detailed description of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. Those skilled in the art can make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A falling film demisting and scrubbing device, characterized in that, The falling film demisting and scrubbing device includes: A steam treatment part, and secondary steam from the outside can flow into the steam treatment part from a falling film evaporator outside. A baffle demister, which includes a housing and a cross-shaped distribution plate. The housing includes a first inner cavity, and the cross-shaped distribution plate is arranged in the first inner cavity. Along a first direction, one end of the first inner cavity communicates with the steam treatment part, and the other end of the first inner cavity is used to communicate with a steam compressor outside. A demisting part, which is arranged in the first inner cavity. Along the first direction, the demisting part is arranged at an interval from the cross-shaped distribution plate. The demisting part includes a plurality of baffle plates and a plurality of trapping hooks. Along a second direction, the plurality of baffle plates are arranged at intervals. Each baffle plate includes a plurality of peak parts. Along the second direction, the peak parts of two adjacent baffle plates face the same direction. Along the first direction, the peak parts of two adjacent baffle plates of each baffle plate face different directions. Each trapping hook corresponds to each peak part. Each trapping hook includes a connecting part and a hook part that are connected. The connecting part is connected to the corresponding peak part. Along the second direction, the hook part is arranged at an interval from the corresponding peak part. In the second direction, the projection of the hook part coincides with the projection of the corresponding peak part. The second direction is perpendicular to the first direction. Wherein, Secondary steam from the outside can flow through a falling film evaporator outside, the steam treatment part, the cross-shaped distribution plate, the demisting part, and a steam compressor outside in sequence.

2. The falling film demisting and gas washing device according to claim 1, wherein The cross-shaped distribution plate includes a first distribution plate and a second distribution plate. The first distribution plate and the second distribution plate extend along the second direction respectively. Along a third direction, the first distribution plate and the second distribution plate are arranged at an interval. The first distribution plate includes a first surface, and the second distribution plate includes a second surface. Along the third direction, the first surface and the second surface are arranged opposite to each other. The distance between the first surface and the second surface increases along the first direction towards the demisting part. The third direction is perpendicular to the first direction. The cross-shaped distribution plate includes a third distribution plate and a fourth distribution plate. The third distribution plate and the fourth distribution plate extend along the third direction respectively. Along the second direction, the third distribution plate and the fourth distribution plate are arranged at an interval. The third distribution plate is connected to the first distribution plate and the second distribution plate, and the fourth distribution plate is connected to the first distribution plate and the second distribution plate. The third distribution plate includes a third surface, and the fourth distribution plate includes a fourth surface. Along the second direction, the third surface and the fourth surface are arranged opposite to each other. The distance between the third surface and the fourth surface increases along the first direction towards the demisting part.

3. The falling film defogging and scrubbing device according to claim 1, characterized in that, Along the second direction, the projection of each hook part covers the projection of the corresponding peak part.

4. The falling film demisting and scrubbing device according to claim 1, characterized in that, The steam treatment unit includes a cyclone separator, the cyclone separator includes a central gas pipe and a first inner wall, the central gas pipe includes a first outer wall, the first inner wall and the first outer wall define a liquid guiding channel, the falling film demisting and gas washing device includes a demister water tank, the demister water tank is respectively communicated with the liquid guiding channel and the first inner cavity, the central gas pipe is communicated with the first inner cavity, and the demister water tank is used for collecting the liquid droplets separated from the secondary steam flowing through the liquid guiding channel and the first inner cavity from the outside.

5. The falling film demisting and scrubbing device according to claim 4, wherein The baffle demister includes a liquid level gauge and a drain pump, the liquid level gauge is electrically connected to the drain pump and the demister water tank respectively, the liquid level gauge is used for detecting the liquid droplet height in the demister water tank, the drain pump is used for starting when the liquid droplet height is higher than the middle position height of the demister water tank, and closing when the liquid droplet height is lower than the set height.

6. The falling film demisting and gas scrubbing device according to claim 1, characterized in that, The steam treatment unit includes a spray gas washer, the falling film demisting and gas washing device includes a steam washing circulating pump, one end of the steam washing circulating pump is communicated with the spray gas washer, the other end of the steam washing circulating pump is used for communicating with an acid adding pump from the outside, and one end of the first inner cavity is communicated with the spray gas washer; The spray gas washer includes a second inner cavity and a plurality of spray heads, the plurality of spray heads are arranged in the second inner cavity, the second inner cavity is communicated with the first inner cavity, the plurality of spray heads are arranged at intervals along the second direction, the steam washing circulating pump includes a steam washing pipeline, the plurality of spray heads are respectively communicated with the steam washing pipeline, the orientations of the plurality of spray heads are the same as the flow direction of the secondary steam from the outside, the falling film demisting and gas washing device includes a demister water tank, the demister water tank is respectively communicated with the second inner cavity and the first inner cavity, and the demister water tank is used for collecting the liquid droplets separated from the secondary steam flowing through the second inner cavity and the first inner cavity from the outside.

7. The falling film demisting and scrubbing device according to claim 6, characterized in that, The falling film demisting and gas washing device further includes a liquid collecting member, the liquid collecting member is respectively communicated with the first inner cavity, the second inner cavity and the demister water tank, and the liquid collecting member is horizontally aligned with the baffle demister.

8. The falling film demisting and scrubbing device according to claim 6, wherein, The baffle demister includes a liquid level gauge, the steam washing circulating pump includes a sewage discharge pipeline, the liquid level gauge is electrically connected to the sewage discharge pipeline and the demister water tank respectively, the liquid level gauge is used for detecting the liquid droplet height in the demister water tank, the sewage discharge pipeline is used for starting when the liquid droplet height is higher than the middle position height of the demister water tank, and closing when the liquid droplet height is lower than the set height; The falling film demisting and gas washing device further includes a water replenishing valve, the liquid level gauge is electrically connected to the water replenishing valve and the acid adding pump from the outside respectively, the demister water tank is respectively communicated with the water replenishing valve and the acid adding pump from the outside, and the water replenishing valve is used for starting the water replenishing valve and the acid adding pump from the outside respectively when the liquid droplet height is lower than the set height.

9. The falling film demisting and scrubbing device according to claim 6, wherein, The baffle demister includes a pH meter, the pH meter is electrically connected to the sewage discharge pipeline, the pH meter is used for detecting the pH value of the liquid droplets in the demister water tank, and the sewage discharge pipeline is used for starting when the pH value is greater than or equal to the set value.

10. The falling film demisting and gas washing device according to claim 1, characterized in that The steam treatment unit includes a spray scrubber. The falling film demisting scrubbing device includes a steam washing circulation pump, which is connected to the spray scrubber. One end of the first inner cavity is connected to the spray scrubber. The spray scrubber includes a second inner cavity and a plurality of spray heads. The plurality of spray heads are arranged in the second inner cavity. The second inner cavity is connected to the first inner cavity. The plurality of spray heads are arranged at intervals along the second direction. The steam washing circulation pump includes a steam washing pipeline. The plurality of spray heads are respectively connected to the steam washing pipeline. The orientations of the plurality of spray heads are the same as the flow direction of the secondary steam from the outside. The falling film demisting scrubbing device includes a demister water tank, which is respectively connected to the second inner cavity and the first inner cavity. The demister water tank is used to collect the liquid droplets separated from the secondary steam from the outside flowing through the second inner cavity and the first inner cavity.

11. The falling film demisting and scrubbing device according to claim 10, characterized in that, The falling film demisting scrubbing device further includes a liquid collecting member, which is respectively connected to the first inner cavity, the second inner cavity and the demister water tank, and is horizontally aligned with the baffle demister.

12. The falling film demisting and gas washing device according to claim 10, characterized in that, The baffle demister includes a liquid level gauge and a conductivity meter. The steam washing circulation pump includes a sewage discharge pipeline. The liquid level gauge is electrically connected to the sewage discharge pipeline and the demister water tank respectively. The liquid level gauge is used to detect the liquid droplet height in the demister water tank. The sewage discharge pipeline is activated when the liquid droplet height is higher than the middle position height of the demister water tank. The conductivity meter is used to detect the conductivity value of the liquid droplets in the demister water tank. The sewage discharge pipeline is activated when the conductivity value is higher than the set value and is closed when the liquid droplet height is lower than the set height. The falling film demisting scrubbing device further includes a water replenishing valve, which is electrically connected to the liquid level gauge and is connected to the demister water tank. The water replenishing valve is activated when the liquid droplet height is lower than the set height.

13. The falling film demisting and gas washing device according to claim 1, characterized in that, The baffle demister includes a spraying part, which includes a first water pipe and a spray head. One end of the first water pipe is used to be connected to a water pump from the outside. The other end of the first water pipe is connected to the spray head. The spray head is arranged in the first inner cavity and faces the plurality of baffle plates along the first direction.

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