A sodium chloride falling film demister

Abstract

The invention discloses a sodium chloride falling film demister, comprising: a demister body; a plurality of baffles staggered and tilted on both sides of the inner wall of the demister body for blocking and separating liquid droplets in steam; a baffle pressure differential sensor is provided on each baffle to detect the pressure difference before and after the baffle blocks and separates liquid droplets; a multi-layered wire mesh plate is provided above the baffle to capture liquid foam in steam; a wire mesh pressure differential sensor is provided on the wire mesh plate to detect the pressure difference before and after the wire mesh plate captures liquid foam; an automatic cleaning system is provided in the demister body and near the position of the wire mesh plate and the baffle for washing the wire mesh plate and the baffle; a central control system is communicated and connected with the baffle pressure differential sensor, the wire mesh pressure differential sensor and the automatic cleaning system, and controls the cleaning of the wire mesh plate and the baffle according to the pressure differential result. The invention can solve the problems of low separation efficiency, easy clogging, and difficult maintenance in traditional sodium chloride evaporation devices.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, in particular to a sodium chloride falling film demister. Background Art

[0002] The sodium chloride falling film demister is a key component of the sodium chloride evaporation and crystallization process. Connected to the sodium chloride falling film evaporator, it is used to isolate and separate droplets and foam formed when some liquid fails to fully vaporize during the evaporation process. The sodium chloride falling film demister's primary function is to separate these droplets and foam from the vapor, preventing them from entering the condenser or subsequent processing equipment, thereby ensuring the normal operation of the system and product quality.

[0003] In traditional sodium chloride evaporation equipment, the demister mostly uses a single baffle or wire mesh structure, which has the following defects: 1. Low separation efficiency: The single structure is insufficient to capture micron-sized droplets, resulting in severe gas-liquid entrainment; 2. Easy to clog: The wire mesh structure is prone to scaling due to droplet adhesion, requiring frequent shutdowns for cleaning; 3. Delayed maintenance: The lack of real-time monitoring means cannot predict performance degradation, and therefore cannot solve the problem of short wire mesh structure life caused by airflow impact.

[0004] Therefore, it is necessary to provide a sodium chloride falling film demister that can overcome the problems of low separation efficiency, easy clogging, and difficult maintenance that exist in traditional sodium chloride falling film demisters.

[0005] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0006] The invention aims to provide a sodium chloride falling film demister, which can solve the problems of low separation efficiency, easy clogging and difficult maintenance existing in traditional sodium chloride evaporation devices.

[0007] To achieve the above object, the present invention provides a sodium chloride falling film demister, comprising:

[0008] The demister body has its lower end connected to the sodium chloride falling film evaporator, and its upper end connected to the condenser and subsequent processing equipment;

[0009] A plurality of baffles are staggered and obliquely arranged on both sides of the inner wall of the demister body, for blocking and separating liquid droplets in the ascending steam generated from the sodium chloride falling film evaporator; a baffle pressure differential sensor is provided on each baffle to detect the pressure difference before and after the baffle blocks and separates the liquid droplets;

[0010] A multi-layered wire mesh plate is provided above the baffle plate to capture residual liquid foam in the ascending steam; a wire mesh pressure differential sensor is provided on the wire mesh plate to detect the pressure difference before and after the wire mesh plate captures the liquid foam;

[0011] An automatic cleaning system is provided in the demister body and near the wire mesh plate and the baffle plate, for flushing the wire mesh plate and the baffle plate;

[0012] a central control system, which is in communication with the baffle plate pressure differential sensor, the screen plate pressure differential sensor and the automatic cleaning system, and controls the automatic cleaning system to start automatic cleaning of the screen plate and / or the baffle plate based on the real-time monitoring of the pressure differential feedback and the separation state of the screen plate and the baffle plate;

[0013] The baffles on each side are tilted downward and form an angle of 30° to 45° with the inner wall of the demister body.

[0014] Optionally, the sodium chloride falling film demister further comprises:

[0015] The buffer portion is a buffer space provided between the baffle plate and the wire mesh plate to reduce the impact of the steam on the wire mesh plate when the steam flows upward;

[0016] A heating component is arranged on the inner wall of the demister body and away from one end of the wire mesh plate, and is used for providing a thermal environment for the steam flowing in the demister body.

[0017] Optionally, the height of the buffer portion is 1 / 5 to 1 / 4 of the diameter of the demister body.

[0018] Optionally, the baffle is corrugated, and the raised structures and recessed structures on its surface are arranged at intervals to improve the efficiency of isolating and separating liquid droplets in the steam.

[0019] Optionally, the surface of the wire mesh plate is coated with a PTFE coating; the porosity of the wire mesh plate is ≥97%.

[0020] Optionally, the automatic cleaning system includes:

[0021] A first automatic cleaning device is provided on the inner wall of the demister body and below the baffle, for spraying and cleaning the baffle;

[0022] The second automatic cleaning device is arranged on the inner wall of the demister body and is located below the wire mesh plate to spray clean the wire mesh plate.

[0023] Optionally, the central control system feeds back the separation state of the baffles according to the monitored pressure difference as follows:

[0024] When the central control system detects that the pressure difference captured by the baffle pressure difference sensor exceeds the baffle pressure difference threshold, a cleaning signal is sent to the first automatic cleaning device to start spray cleaning of the baffle.

[0025] Optionally, the central control system can monitor the pressure difference and feedback the separation status of the screen plate as follows:

[0026] When the central control system detects that the pressure difference captured by the screen plate pressure difference sensor exceeds the screen plate pressure difference threshold, a cleaning signal is sent to the second automatic cleaning device to start spray cleaning of the screen plate.

[0027] Optionally, the baffle pressure difference threshold is set to ΔP1≤0.5-1 kPa; the wire mesh plate pressure difference threshold is set to ΔP2≤1.5-3 kPa.

[0028] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The sodium chloride falling film demister provided by the present invention adopts baffles and wire mesh plates for multi-stage separation, which has better separation effect on large droplets and liquid foam in steam and higher separation efficiency.

[0030] 2. The sodium chloride falling film demister provided by the present invention is equipped with an intelligent monitoring and cleaning system, which makes it less prone to clogging, easier to maintain, and reduces the frequency of manual inspections, thereby improving production safety.

[0031] 3. The sodium chloride falling film demister provided by the present invention is suitable for high-salt and high-humidity working conditions, with a prolonged continuous operation cycle of the equipment and lower maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the sodium chloride falling film demister of the present invention;

[0033] Figure 2 Schematic diagram of the baffle structure of the present invention;

[0034] Figure 3 It is a schematic diagram of the wire mesh plate structure of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the attached Figures 1-3, the present invention is further described in detail through preferred embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention, so they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0036] The sodium chloride falling film demister with intelligent monitoring function is used to separate droplets and foam in the steam after sodium chloride falling film evaporation, so as to prevent the droplets and foam from entering the condenser and other post-processing equipment and affecting the system operation and product quality.

[0037] The present invention provides a sodium chloride falling film demister, such as Figure 1 As shown, the sodium chloride falling film demister includes: a demister body, the lower end of which is connected to the sodium chloride falling film evaporator 100, and the upper end of which is connected to the condenser 300 and the subsequent processing equipment; a plurality of baffles 200, staggered and inclined on both sides of the inner wall of the demister body, for blocking and separating large droplets in the ascending steam generated from the sodium chloride falling film evaporator 100; a wire mesh plate 400, arranged above the baffle 200, for capturing residual liquid foam in the ascending steam; a plurality of baffle pressure difference sensors 201, respectively arranged on each of the baffles 200, for detecting the pressure difference before and after the baffle 200 blocks and separates the large droplets; a wire mesh pressure difference sensor 401, arranged on the wire mesh plate 400, for detecting the pressure difference before and after the baffle 200 blocks and separates the large droplets To detect the pressure difference before and after the wire mesh plate 400 captures the liquid foam; an automatic cleaning system is arranged in the demister body, and is close to the wire mesh plate 400 and the baffle 200, for flushing the wire mesh plate 400 and the baffle 200; a heating component 500 is arranged on the inner wall of the demister body, and is away from one end of the wire mesh plate 400, for providing a thermal environment for the steam flowing in the demister body to maintain the vaporization temperature and prevent condensation; a central control system is communicated with the baffle pressure differential sensor 201, the wire mesh plate pressure differential sensor 401 and the automatic cleaning system to feedback the separation status according to real-time monitoring of the pressure difference, and to select to start automatic cleaning of the wire mesh plate 400 and / or the baffle 200.

[0038] Among them, such as Figure 2As shown, the baffle 200 is corrugated, and the raised structures and recessed structures on its surface are arranged at intervals. The surface structure of the baffle 200 changes the airflow path of the steam in the sodium chloride falling film demister when it flows upward through the baffle 200, making the turbulence more obvious, thereby effectively speeding up the time for the droplets to collide and condense onto the baffle 200, thereby improving the barrier separation efficiency of the droplets in the steam.

[0039] Preferably, the plurality of baffles 200 are all made of 316L stainless steel, and are arranged to be tilted downward, and form an angle of 30° to 45° with the inner wall of the demister body.

[0040] Furthermore, the baffle 200 includes a plurality of first baffles 210, which are arranged on one side of the inner wall of the demister body and are arranged up and down at a certain distance along the extension direction of the inner wall, and each of the first baffles 210 is tilted downward relative to its installation point with the inner wall of the demister body; wherein, the first baffle 210 is at an angle of 30°~45° to the inner wall of the demister body on its installation side.

[0041] The baffle 200 also includes a plurality of second baffles 220, which are arranged on the other side of the inner wall of the demister body and are arranged up and down at a certain distance along the extension direction of the inner wall of this side, and each of the second baffles 220 is inclined downward relative to its installation point with the inner wall of the demister body; wherein, the second baffle 220 is at an angle of 30°~45° to the inner wall of the demister body on the side on which it is installed.

[0042] In addition, each of the first baffles 210 and each of the second baffles 220 are arranged in an alternating manner, that is, the installation point of the top first baffle 210 and the inner wall of the demister body is the highest, the installation point of the top second baffle 220 and the inner wall of the demister body is slightly lower, the installation point of the second top first baffle 210 and the inner wall of the demister body is even lower, and the installation point of the second top second baffle 220 on the inner wall of the demister body is the lowest; furthermore, a similar spatial position relationship is formed at the ends of the top first baffle 210, the top second baffle 220, the second top first baffle 210, and the second top second baffle 220 away from their respective installation points, that is, the height of the end of the top first baffle 210 away from its installation point > the height of the end of the top second baffle 220 away from its installation point > the height of the end of the second top first baffle 210 away from its installation point > the height of the end of the second top second baffle 220 away from its installation point. Furthermore, one end of each first baffle 210 and one end of each second baffle 220 away from the installation point exceeds the central axis of the demister body to ensure that the liquid droplets in the steam are completely blocked and separated.

[0043] Among them, such as Figure 3As shown, the screen plate 400 is a multi-layer structure and is made of stainless steel, and its surface is coated with PTFE (polytetrafluoroethylene). Therefore, the surface of the screen plate 400 is highly hydrophobic, and small droplets are not easy to adhere, which significantly reduces the risk of the screen plate 400 being blocked by small droplets.

[0044] Preferably, the wire mesh plate 400 is provided with 2 to 3 layers to ensure that the residual liquid foam in the steam is completely captured; the outer diameter of the mesh wire constituting the wire mesh plate 400 is 0.1 to 0.4 mm, the porosity is ≥97%, and the PTFE (polytetrafluoroethylene) coating thickness is 10 to 20 μm.

[0045] In which, the sodium chloride falling film demister also includes: a buffer portion 600, which is a buffer space located inside the demister body and arranged between the baffle 200 and the wire mesh plate 400, that is, a gap is set between the baffle 200 and the wire mesh plate 400 to form the buffer portion 600, and the buffer portion 600 is used to slow down the speed of steam flowing upward from the baffle 200 through the wire mesh plate 400, so as to reduce the impact of the steam airflow on the wire mesh plate 400, thereby extending the service life of the wire mesh plate 400.

[0046] Preferably, the height of the buffer portion 600 is 1 / 5 to 1 / 4 of the diameter of the demister body; and the air flow velocity of the steam is controlled at 3 to 5 m / s.

[0047] In which, the automatic cleaning system includes: a first automatic cleaning device 701, which is fixedly arranged on the inner wall of the demister body and located below the baffle 200, so as to spray the baffle 200 after a large amount of liquid droplets and particulate matter are gathered on the baffle 200; a second automatic cleaning device 702, which is fixedly arranged on the inner wall of the demister body and located below the wire mesh plate 400, so as to spray the wire mesh plate 400 after a large amount of liquid foam and particulate matter are suspended on the wire mesh plate 400.

[0048] Specifically, the first automatic cleaning device 701 includes: a spray pipe fixedly connected to the inner wall of the demister body, and a plurality of spray heads installed on the spray pipe; wherein, the spray pipe is connected to an external water supply system, and can turn on the spray head to clean the baffle 200 after receiving a cleaning signal from the central control system; the structure and cleaning method of the second automatic cleaning device 702 are the same as those of the first automatic cleaning device 701.

[0049] Furthermore, a plurality of the baffle pressure differential sensors 201 are arranged at the end of each of the baffles 200; when steam flows through the baffles 200, after particles and large droplets adhere to the surface of the baffles 200, the resistance to the upward flow of the sodium chloride crystal salt vapor gradually increases, resulting in different forces on the side of the baffle 200 with the raised structure and the other side with the recessed structure; the baffle pressure differential sensor 201 obtains the pressure difference on each of the baffles 200 by detecting the pressure on both sides of each of the baffles 200.

[0050] In a specific embodiment of the present invention, the baffle pressure difference sensor 201 is arranged at one end of each baffle 200 close to the inner wall of the demister body.

[0051] Furthermore, when the wire mesh plate pressure difference sensor 401 is working, as the sodium chloride crystal salt vapor flows upward, particles, small droplets and liquid foam gradually adhere to the surface of the wire mesh plate 400, and the upper and lower sides of the wire mesh plate 400, that is, the inflow side and the outflow side of the steam are subject to different resistances; the wire mesh plate pressure difference sensor 401 obtains the pressure difference by detecting the resistance of the wire mesh plate 400 on the inflow side surface and the outflow side surface.

[0052] In a specific embodiment of the present invention, the baffle plate differential pressure sensor 201 and the screen plate differential pressure sensor 401 are high-precision differential pressure sensors (with a range of 0-10 kPa). Specifically, both the baffle plate differential pressure sensor 201 and the screen plate differential pressure sensor 401 used in the present invention are Liansen SIN-P300G.

[0053] Furthermore, there is a communication connection between the central control system, the baffle pressure difference sensor 201, the wire mesh plate pressure difference sensor 401 and the automatic cleaning system.

[0054] Specifically, when the central control system detects that the pressure difference captured by the baffle pressure differential sensor 201 exceeds the baffle pressure differential threshold, it indicates that too many particles and droplets are gathered on the surface of the baffle 200, and the separation efficiency of the baffle 200 is poor, then an alarm is triggered, and a cleaning signal is sent to the first automatic cleaning device 701 to start spray cleaning of the baffle 200; when the central control system detects that the pressure difference captured by the baffle pressure differential sensor 201 is within the baffle pressure differential threshold, it indicates that too many particles and droplets are not gathered on the surface of the baffle 200, and the baffle 200 can better separate the droplets in the steam.

[0055] In addition, when too many droplets gather on the surface of the baffle 200, or the pressure of the incoming sodium chloride vapor is too high, resulting in a too large pressure difference on the surface of the baffle 200 (i.e., exceeding the baffle pressure difference threshold), the inclined baffle 200 may be easily fallen off and damaged; and through the setting of the baffle pressure difference sensor 201, when the pressure difference exceeds the baffle pressure difference threshold, an alarm will be triggered and the baffle 200 will be sprayed and cleaned, so that the pressure difference on the surface of the baffle 200 returns to within the pressure difference threshold range, which also makes the operation time of the sodium chloride falling film demister longer, and the fragile baffle 200 is promptly maintained during operation.

[0056] When the central control system detects that the pressure difference captured by the wire mesh plate pressure difference sensor 401 exceeds the wire mesh plate pressure difference threshold, it indicates that too many particles, small droplets and liquid foam are attached to the surface of the wire mesh plate 400, and the separation efficiency of the wire mesh plate 400 is poor, then the alarm is triggered, and a cleaning signal is sent to the second automatic cleaning device 702 to start the spray cleaning of the wire mesh plate 400; when the central control system detects that the pressure difference captured by the wire mesh plate pressure difference sensor 401 is within the wire mesh plate pressure difference threshold, it indicates that too many particles, small droplets and liquid foam are not attached to the surface of the wire mesh plate 400, and the wire mesh plate 400 can better separate the liquid foam in the steam.

[0057] In a specific embodiment of the present invention, the pressure difference threshold of the baffle is set to ΔP1≤0.5-1 kPa; the pressure difference threshold of the wire mesh plate is set to ΔP2≤1.5-3 kPa.

[0058] In summary, the sodium chloride falling-film demister provided by this invention is suitable for use in MVR (mechanical vapor recompression) sodium chloride evaporators and high-salt wastewater treatment systems. It is compatible with the separation needs of salts such as sodium sulfate and magnesium chloride and is suitable for retrofitting existing evaporation and concentration production lines. Furthermore, through multi-stage separation, intelligent monitoring, and cleaning, this sodium chloride falling-film demister boasts high separation efficiency, is non-clogging, and is easy to maintain.

[0059] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0060] In the description of the present invention, it should be understood that the terms "center," "height," "thickness," "up," "down," "vertical," "horizontal," "top," "bottom," "inside," "outside," "axial," "radial," "circumferential," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0061] In the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0062] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0063] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. After reading the above description, various modifications and substitutions of the present invention will become apparent to those skilled in the art. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A sodium chloride falling film demister, characterized in that: include: The demister body has a lower end connected to a sodium chloride falling film evaporator (100), and an upper end connected to a condenser (300) and subsequent processing equipment; A plurality of baffles (200) are staggered and obliquely arranged on both sides of the inner wall of the demister body, and are used to block and separate liquid droplets in the ascending steam generated from the sodium chloride falling film evaporator (100); a baffle pressure difference sensor (201) is provided on each baffle (200) to detect the pressure difference before and after the baffle (200) blocks and separates the liquid droplets; A multi-layered wire mesh plate (400) is provided above the baffle plate (200) and is used to capture residual liquid foam in the ascending steam; a wire mesh plate pressure difference sensor (401) is provided on the wire mesh plate (400) to detect the pressure difference before and after the wire mesh plate (400) captures the liquid foam; an automatic cleaning system, disposed in the demister body and close to the wire mesh plate (400) and the baffle plate (200), for flushing the wire mesh plate (400) and the baffle plate (200); a central control system, which is in communication with the baffle plate pressure differential sensor (201), the screen plate pressure differential sensor (401) and the automatic cleaning system, and controls the automatic cleaning system to start automatic cleaning of the screen plate (400) and / or the baffle plate (200) based on the real-time monitoring of the pressure differential feedback of the separation state of the screen plate (400) and the baffle plate (200); The baffles (200) on each side are arranged to be tilted downward and to form an angle of 30° to 45° with the inner wall of the demister body; The automatic cleaning system comprises: a first automatic cleaning device (701) and a second automatic cleaning device (702); When the central control system detects that the pressure difference captured by the baffle pressure difference sensor (201) exceeds the baffle pressure difference threshold, a cleaning signal is sent to the first automatic cleaning device (701) to start spray cleaning of the baffle (200); When the central control system detects that the pressure difference captured by the screen plate pressure difference sensor (401) exceeds the screen plate pressure difference threshold, a cleaning signal is sent to the second automatic cleaning device (702) to start spray cleaning of the screen plate (400).

2. The sodium chloride falling film demister as claimed in claim 1, wherein The sodium chloride falling film demister also comprises: The buffer portion (600) is a buffer space provided between the baffle plate (200) and the wire mesh plate (400) to reduce the impact of steam on the wire mesh plate (400) when the steam flows upward; A heating component (500) is arranged on the inner wall of the demister body and at one end away from the wire mesh plate (400), and is used to provide a thermal environment for the steam flowing in the demister body.

3. Sodium chloride falling film demister as claimed in claim 2, is characterized in that, The height of the buffer portion (600) is 1 / 5 to 1 / 4 of the diameter of the demister body.

4. Sodium chloride falling film demister as claimed in claim 1, characterized in that, The baffle (200) is corrugated, and the convex structures and concave structures on its surface are arranged at intervals to improve the barrier and separation efficiency of liquid droplets in steam.

5. The sodium chloride falling film demister as claimed in claim 1, wherein The surface of the wire mesh plate (400) is coated with a PTFE coating; the porosity of the wire mesh plate (400) is ≥97%.

6. Sodium chloride falling film demister as claimed in claim 1, characterized in that, The first automatic cleaning device (701) is arranged on the inner wall of the demister body and is located below the baffle (200) to spray and clean the baffle (200); The second automatic cleaning device (702) is arranged on the inner wall of the demister body and is located below the wire mesh plate (400) to spray clean the wire mesh plate (400).

7. The sodium chloride falling film demister as claimed in claim 1, wherein The pressure difference threshold of the baffle is set to ΔP1≤0.5-1kPa; the pressure difference threshold of the wire mesh plate is set to ΔP2≤1.5-3kPa.

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