A respiratory mist eliminator and respiratory mist elimination system

Abstract

The utility model discloses a kind of breathing demister and breathing demisting system, belong to industrial waste gas treatment equipment technical field.The breathing demister includes shell, at least one hydrophobic membrane filter element is vertically arranged in shell by filter element mounting seat and mounting hole;Breathing port is equipped in shell side wall, central bottom is equipped with inlet / outlet port, one side of bottom is equipped with liquid discharge port.The breathing demisting system is connected by above-mentioned demister and atmospheric vessel, and the breathing interface of container top is communicated with the inlet / outlet port of demister, and the breathing port of demister is communicated with atmosphere.The utility model is compact in structure, utilizes hydrophobic membrane filter element to realize the two-way gas-liquid separation function of atmospheric vessel when " exhale " remove acid mist, " inhale " remove moisture, radically solves unorganized emission pollution and tank body corrosion problem from equipment structure, and without external power, safe and environmentally friendly.

Description

Technical Field

[0001] This utility model relates to the field of environmental protection treatment technology for breathing exhaust gas from containers, equipment, and facilities at normal temperature and pressure, as well as related equipment technology. Specifically, it relates to a breathing demister and breathing demister system used in a sulfuric acid mist removal process. Background Technology

[0002] In the early stages of sulfuric acid production and storage, atmospheric pressure containers and equipment such as storage tanks, intermediate tanks, circulating acid tanks, and loading platforms were typically managed using vent pipes for direct discharge and absorption into the atmosphere. When sulfuric acid was introduced into the tank, gases carrying a certain amount of acidic mist and droplets were directly discharged into the atmosphere through the vent pipes, easily causing unorganized pollution to the surrounding environment. Because concentrated sulfuric acid is hygroscopic, when sulfuric acid was transported out of the tank, humid air from the outside was directly drawn into the storage tank through the vent pipes. The moisture in this air came into contact with the concentrated sulfuric acid on the tank surface, locally forming a diluted sulfuric acid solution. This damaged the passivation film on the tank wall, corroding the tank walls at the liquid level, affecting the tank's service life, and creating safety risks.

[0003] In recent years, sulfuric acid plants have improved the breathing balance method of the above-mentioned equipment. One method is to install concentrated sulfuric acid liquid seal on the breathing vent pipe. When the tank is inhaling, the humid air is dried after passing through the concentrated sulfuric acid liquid seal, which protects the tank wall and avoids the risk of tank corrosion. However, the concentrated sulfuric acid in the liquid seal can still cause corrosion after absorbing water and being diluted. Therefore, the concentrated sulfuric acid in the liquid seal needs to be replaced frequently, which increases the operational risk. Moreover, when the tank is exhaling, the acid seal cannot effectively absorb and intercept the acid mist in the "aerosol" state. At this time, due to the bubbling effect of the air in the tank passing through the liquid seal, the liquid seal carries more sulfuric acid mist into the atmosphere. This not only causes more serious fugitive emissions pollution to the nearby atmosphere, but also causes large acid particles to fall back to the tank surface due to gravity, causing corrosion damage to the outer shell of the tank. Another approach involves connecting a pipeline to the sulfuric acid production unit via the vent pipe. The acidic mist from the tank's exhalation can be directly absorbed by the unit, preventing atmospheric pollution. When the tank draws in air, it draws in relatively dry air from the unit, avoiding equipment corrosion. However, this method requires a long pipeline, ranging from tens to hundreds of meters, resulting in significant investment. Its biggest drawback is that it cannot be used during sulfuric acid unit shutdowns for maintenance; the valve must be closed, and the system must switch to a standby port for direct air intake, thus not completely resolving the corrosion and pollution issues. Yet another approach uses nitrogen sealing. A breather valve is installed on the vent pipe. When the tank draws in air, nitrogen enters through the breather valve to maintain the nitrogen seal. Because nitrogen has very low moisture content, corrosion is largely eliminated. However, when the tank exhales, it still directly releases acidic mist into the atmosphere through the breather valve, failing to solve the problem of fugitive emissions and increasing the cost of nitrogen usage and long-distance pipelines.

[0004] In summary, existing technical solutions either suffer from pollution and corrosion defects, or are complex and costly. The root cause lies in the lack of a dedicated device with a simple structure, high integration, and the ability to simultaneously and efficiently handle both exhaled and inhaled airflow during respiration. Therefore, there is an urgent need for a new type of respiratory demisting device that can achieve bidirectional purification once and for all through its own physical structure, thereby fundamentally solving the aforementioned problems. Utility Model Content

[0005] The purpose of this utility model is to provide a highly efficient and environmentally friendly breathing demister and breathing demister system for the treatment of acidic gases, so as to solve the pollution of the surrounding environment caused by the unorganized emissions from atmospheric pressure containers, equipment and facilities such as storage tanks, intermediate tanks, circulating acid tanks, and loading platforms of sulfuric acid production and storage enterprises due to breathing balance, as well as the safety and personnel operation risks of the above-mentioned equipment and facilities.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A breathing defroster includes a housing, inside which a filter element mounting base is provided. The filter element mounting base is provided with at least one vertically mounted filter element mounting hole, and at least one hydrophobic membrane filter element is fitted onto the filter element mounting hole. A breathing port is provided on the side wall of the housing, and an air inlet / outlet connected to the filter element mounting base is provided at the center of its bottom. A drain port is also provided on one side of its bottom.

[0007] Furthermore, the hydrophobic membrane filter element is a pleated membrane cylindrical structure, including an inner / outer skeleton tube made of PFA material and a PTFE pleated hydrophobic filter membrane disposed between the inner / outer skeleton, a bottom mounting clip with air inlet / outlet function, and a top triangular or flat sealing cap.

[0008] Furthermore, the filter element mounting base of the demister is an integral structure with the demister inlet / outlet / air port. The lower part is the inlet / outlet / air port, and the upper part is the filter element mounting base, which is connected and fixed in the middle by a pipe. The inner / outer layer central skeleton tube of the demister filter element is densely covered with through holes. The PTFE pleated hydrophobic filter membrane is set in the middle of the double-layer PFA skeleton, and the bottom of the filter element is fitted with a snap-fit ​​connector that is sealed to the filter element mounting hole.

[0009] Furthermore, the inner and outer surfaces of the housing are sandblasted, and both the inner and outer walls are coated with an F46 fluoroplastic anti-corrosion layer.

[0010] Furthermore, the top of the housing is connected to a top cover via a flange, and both the inner and outer walls of the top cover are coated with an F46 fluoroplastic anti-corrosion layer.

[0011] Furthermore, the filter element mounting base is uniformly provided with one or more vertically installed filter element mounting holes, the number of which is the same as the number of filter elements, and the hydrophobic membrane filter elements are respectively installed on the holes.

[0012] Preferably, the shell is a cylindrical shell.

[0013] A breathing defogging system, comprising: A respirator as described above; An atmospheric pressure vessel, wherein the breathing port at the top of the atmospheric pressure vessel is connected to the inlet / outlet of the breathing demister via a pipe, wherein the breathing port of the breathing demister is in communication with the atmosphere.

[0014] The atmospheric pressure vessel is also equipped with a pressure gauge on the top, and other corresponding parts are equipped with a breathing port, material inlet and outlet.

[0015] The atmospheric pressure vessel is one of the following: a storage tank, intermediate tank, circulation tank, or loading platform for sulfuric acid, phosphoric acid, silicic acid, inorganic alkaline solution, or salt solution.

[0016] This invention features a special "breathing demister" installed at the breathing port of containers and equipment. When the equipment needs to exhale acidic waste gas during the feeding process, the demister removes the mist from the waste gas before emission. When the equipment needs to draw in outside air during the material delivery process, the demister intercepts the moisture in the air before drawing it into the equipment. This achieves both environmentally friendly emissions and equipment protection, while also increasing the safety of the operation process. Attached Figure Description

[0017] Figure 1 This is a front view of the breathing demister of this utility model; Figure 2 This is a left view of the breathing demister of this utility model; Figure 3 This utility model Figure 1 AA section view in the middle; Figure 4 This is a schematic diagram of the filter element installation of this utility model; Figure 5 This is a schematic diagram of the combination of the present invention's breathing demisting device and a sulfuric acid storage tank. Detailed Implementation

[0018] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] When process liquid materials enter a closed container, under the premise of constant temperature, the material occupies the space of the container, which compresses the gas inside the container and causes the internal pressure of the container to rise. Conversely, when the liquid material in the container is discharged outward, a negative pressure is formed inside the storage tank, which affects the material transportation and equipment safety. Therefore, in industry, the method of designing a breather vent for atmospheric pressure containers is often used to maintain the stability of the internal pressure of the container.

[0022] This invention focuses on utilizing hydrophobic membrane technology. When gas containing fine liquid droplets flows through the membrane filter element, the fine liquid droplets are intercepted by the hydrophobic membrane without affecting gas flow, thus achieving gas-liquid separation. The breathing demister used in this invention is a cartridge-type filter, with the key component being a pleated membrane filter element. The filter element frame is made of PFA material, and the hydrophobic membrane is made of PTFE material. The membrane's filtration accuracy reaches 0.01μm, achieving 100% removal of droplets >1μm from the gas and a 99.9% removal rate for droplets ≤1μm. Process verification shows that the overall demisting efficiency of the breathing demister reaches 99.99%.

[0023] See Figure 1-5 As shown: A breathing demister includes a housing 1. The shape of the housing 1 can be set according to actual needs. In this embodiment, it is preferably a cylindrical housing. A filter element mounting seat 2 is provided inside the housing 1. The filter element mounting seat 2 is provided with at least one vertically mounted filter element mounting hole 9. At least one hydrophobic membrane filter element 4 is fitted onto the filter element mounting hole 9 through the filter element mounting clip at the bottom of the filter element. A breathing port 5 is provided on the side wall of the housing 1. An air inlet / outlet 6 connected to the filter element mounting seat 2 is provided at the center of its bottom. A drain port 7 is also provided on one side of its bottom. A top cover 8 is provided on the top.

[0024] In a preferred embodiment of this utility model, the hydrophobic membrane filter element 4 is a folded membrane cylindrical structure, including an inner / outer skeleton tube made of PFA material and a PTFE folded hydrophobic filter membrane disposed between the inner / outer skeleton tube; the inner / outer skeleton tube is densely covered with through holes, and the bottom of the filter element has a mounting clip with air inlet / outlet function that is sealed to the filter element mounting hole 9 on the filter element mounting base 2. The top of the filter element is provided with a triangular or flat sealing cap 3.

[0025] In a preferred embodiment of this utility model, the inner and outer surfaces of the shell are sandblasted, and both the inner and outer walls are coated with an F46 fluoroplastic anti-corrosion layer.

[0026] In a preferred embodiment of the present invention, the top of the housing 1 is connected to a top cover 8 via a flange, and the inner and outer walls of the top cover 8 are coated with an F46 fluoroplastic anti-corrosion layer.

[0027] In this embodiment, one or more vertically installed filter element mounting rod holes 9 are uniformly arranged on the filter element mounting base 2, and the hydrophobic membrane filter element 4 is respectively arranged on them. In actual application, the number of filter element mounting holes 9 can be set according to the required filtration area to calculate the number of filter elements. For example, the number of filter element mounting holes 9 can be 2, 3, 4, 5, 6, etc.

[0028] like Figure 5 As shown, this utility model also provides a breathing demisting system, comprising: One of the above-mentioned breathing defrosters 10; An atmospheric pressure vessel 20 has a breather port 25 at the top of the atmospheric pressure vessel 20 connected to the inlet / outlet port 6 of a breather demister via a pipe. The breather port 5 of the breather demister is in communication with the atmosphere.

[0029] The atmospheric pressure vessel is also equipped with a pressure gauge 21, a spare breathing port 22, a material inlet 23, and a material outlet 24.

[0030] Specifically, an atmospheric pressure vessel is one of the following: a storage tank, intermediate tank, circulation tank, or loading platform for sulfuric acid, phosphoric acid, silicic acid, inorganic alkaline solution, or salt solution.

[0031] Example 1: Take the breathing and demisting system of a 3000m³ concentrated sulfuric acid storage tank as an example.

[0032] The main purpose of concentrated sulfuric acid storage tanks is to store sulfuric acid with a concentration of 98%.

[0033] After the concentrated sulfuric acid produced by the sulfuric acid production unit passes inspection, it is pumped to the acid inlet at the top of the storage tank for storage. When the sulfuric acid leaves the tank, it is pumped through the acid outlet at the bottom of the storage tank to nearby acid-using units or loading docks for loading and sale.

[0034] The simplified process flow diagram of Example 1 is shown in Figure 5.

[0035] The two working states of its process flow are described below: 1. Sulfuric acid inlet - gas outlet state: When concentrated sulfuric acid enters the 3000m³ sulfuric acid storage tank from the top, the sulfuric acid mist gas in the tank is discharged from the "inlet / outlet" connected to the bottom of the breather demister at the top of the tank. After the sulfuric acid mist is removed by the breather demister, it is discharged outward from the "breathing port" of the breather demister, so that the storage tank maintains constant pressure. The removed sulfuric acid mist forms droplets and flows back into the tank from the "inlet / outlet" of the breather demister.

[0036] 2. Sulfuric acid out-air in state: When concentrated sulfuric acid is sent out of the 3000m³ sulfuric acid storage tank from the bottom, the humid air outside the tank enters through the "breathing port" of the breather demister at the top of the tank. After the breather demister removes moisture, the air enters the tank through the "inlet / outlet" connecting the bottom of the breather demister to the top of the tank, thus maintaining constant pressure in the tank. The removed moisture forms droplets that fall to the bottom of the breather demister shell and are discharged into the water collection ditch through the "drain port" of the breather demister.

[0037] Table 2. Main process parameters of the breathing and demisting system for a 3000 m³ concentrated sulfuric acid storage tank.

[0038] Table 3. Design parameters for the breathing demister of a 3000 m³ concentrated sulfuric acid storage tank.

[0039] Example 2: Take the breathing and demisting system of a 100m³ sulfuric acid intermediate analysis tank as an example.

[0040] The main purpose of the concentrated sulfuric acid intermediate analysis tank is to temporarily store 98% concentrated sulfuric acid sent from the production unit. After sampling and analysis, qualified products are pumped by acid pump to the finished product storage tank for storage, while unqualified products are pumped by acid pump to the substandard product storage tank for further processing.

[0041] The process flow of Example 2 is basically the same as that of Example 1, and its simplified process flow diagram is as follows: Figure 5 As shown.

[0042] The two working states of its process flow are described below: 1. Sulfuric acid inlet-gas outlet state: When concentrated sulfuric acid enters the 100m³ concentrated sulfuric acid intermediate analysis tank from the top, the sulfuric acid mist gas in the tank is discharged from the "inlet / outlet" connected to the bottom of the breathing demister at the top of the intermediate analysis tank. After the sulfuric acid mist is removed by the breathing demister, it is discharged outward from the "breathing port" of the breathing demister, so that the tank is kept at constant pressure. The removed sulfuric acid mist forms droplets and flows back into the tank from the "inlet / outlet" of the breathing demister.

[0043] 2. Sulfuric acid out-air in state: When concentrated sulfuric acid is discharged from the bottom of the 100m³ intermediate analysis tank, the humid air outside the tank enters through the "breathing port" of the breathing demister at the top of the intermediate analysis tank. After the breathing demister removes moisture, the air enters the tank through the "inlet / outlet" connected to the top of the intermediate analysis tank at the bottom of the breathing demister, so as to maintain constant pressure in the tank. The removed moisture forms droplets that fall to the bottom of the breathing demister shell and are discharged into the water collection ditch through the "drain port" of the breathing demister.

[0044] Table 4. Main process parameters of the breathing and demisting system for the 100m³ concentrated sulfuric acid intermediate analysis tank.

[0045] Table 5. Design parameters for the breathing demister of the 100m³ concentrated sulfuric acid intermediate analysis tank.

[0046] After being put into use, the above-mentioned Embodiments 1 and 2 operated normally. After repeated on-site sampling tests, no sulfuric acid mist components were detected in the gas exhaled from the breathing port of the breathing defogger, and no corrosion traces of sulfuric acid mist were found around the breathing port. Based on the overall judgment, the demisting efficiency is >99.99%.

[0047] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0048] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A breathing defogger, comprising a housing, characterized in that, The housing is provided with a filter element mounting base inside, and the filter element mounting base is provided with at least one vertically mounted filter element mounting hole. At least one hydrophobic membrane filter element is fitted into the filter element mounting hole. The side wall of the housing is provided with a vent, and the bottom center is provided with an air inlet / outlet connected to the filter element mounting base. A drain outlet is also provided on one side of the bottom.

2. The breathing defogger according to claim 1, characterized in that, The hydrophobic membrane filter element is a pleated membrane cylindrical structure, including an inner / outer skeleton tube made of PFA material and a PTFE pleated hydrophobic filter membrane disposed between the inner / outer skeleton, a bottom mounting clip with air inlet / outlet function, and a top triangular or flat sealing cap.

3. The breathing demister according to claim 2, characterized in that, The filter element mounting base of the demister is an integral structure with the demister inlet / outlet. The lower part is the inlet / outlet, and the upper part is the filter element mounting base. They are connected and fixed in the middle by a pipe. The inner / outer layer central skeleton tube of the demister filter element is densely covered with through holes. The PTFE pleated hydrophobic filter membrane is set in the middle of the double-layer PFA skeleton. The bottom of the filter element is installed with a snap-fit ​​connector and sealed to the filter element mounting hole.

4. The breathing defogger according to claim 1, characterized in that, The inner and outer surfaces of the housing are sandblasted, and both the inner and outer walls are coated with an F46 fluoroplastic anti-corrosion layer.

5. The breathing defogger according to claim 1, characterized in that, The top of the housing is connected to a top cover via a flange, and the inner and outer walls of the top cover are coated with an F46 fluoroplastic anti-corrosion layer.

6. The breathing defogger according to claim 1, characterized in that, The filter element mounting base is uniformly provided with one or more vertically installed filter element mounting holes, the number of which is the same as the number of filter elements, and the hydrophobic membrane filter elements are respectively installed on the holes.

7. The breathing demister according to claim 1, characterized in that: The shell is a cylindrical shell.

8. A breathing demisting system, characterized in that, include: A respirator according to any one of claims 1-7; An atmospheric pressure vessel, wherein the breathing port at the top of the atmospheric pressure vessel is connected to the inlet / outlet of the breathing demister via a pipe, wherein the breathing port of the breathing demister is in communication with the atmosphere.

9. The respirator demisting system according to claim 8, characterized in that: The atmospheric pressure vessel is also equipped with a pressure gauge on the top, and other corresponding parts are equipped with a breathing port, material inlet and outlet.

10. The respirator demisting system according to claim 8, characterized in that: The atmospheric pressure vessel is one of the following: a storage tank, intermediate tank, circulation tank, or loading platform for sulfuric acid, phosphoric acid, silicic acid, inorganic alkaline solution, or salt solution.

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