Self-cleaning uniform flow ventilation device for evaluating chemical filter

Abstract

The application discloses a self-cleaning and uniform-flow ventilation device for chemical filter evaluation, which comprises a pre-filtering section, a pre-mixing conversion section, a mixing bin, a post-mixing conversion section, a filter-to-be-tested section, a fan conversion section and a fan. An inlet of the pre-filtering section is used as an air inlet, and an outlet is connected with the front end of the mixing bin through the pre-mixing conversion section. The inside of the mixing bin is used as an air and target gas mixing section. The mixing bin comprises a hollow first cylinder, and the post-mixing conversion section comprises a hollow second cylinder. The hollow first cylinder and the hollow second cylinder are connected through a plurality of variable-diameter bodies. A target gas inlet pipeline is connected to the hollow first cylinder, and a flow guide mechanism, a cleaning ventilation mechanism and a filtering mechanism are arranged in the inside. Meanwhile, the cleaning ventilation mechanism is also arranged in the inside of the hollow second cylinder. The application can guide flow, reduce resistance, realize high-efficiency uniform flow, maintain a long service life, reduce the requirement for fan pressure head, save energy and reduce carbon, and ensure the cleanliness of the airflow.

Description

Technical Field

[0001] This invention relates to a self-cleaning, uniform flow ventilation device for evaluating chemical filters, belonging to the field of air purification technology. Background Technology

[0002] The ventilation devices currently used for the filters under test have the following main drawbacks:

[0003] (1) The target gas introduced by the ventilation device is flammable and explosive, and the initial dispersion into the air duct poses a high risk. The method of increasing humidity to ensure safety is limited to test conditions where humidity requirements are low. For test conditions where humidity needs to be fixed, how to quickly mix the target airflow and dilute it to a certain concentration is a challenging problem.

[0004] (2) Affected by gravity, the location of the target gas, air volume, air inlet opening, and end fan opening, the airflow distribution in the ventilation device is prone to local concentration, which leads to abnormal adsorption efficiency results of the filter under test.

[0005] (3) Flow equalization devices, especially perforated plates, usually have a large pressure loss effect, which puts high demands on the fan. Increasing the fan head means a significant increase in cost, and the installation space is larger, making it more difficult to achieve flow regulation stability.

[0006] (4) Conventional perforated flow equalization mesh is prone to corrosion after being impacted by acidic gas for a long time. Tiny void defects are generated on the surface, and concentrated chemical components remain. Corrosion debris can flow with the airflow to downstream filters, precision equipment, etc., causing background interference in the ventilation device, premature equipment failure, frequent replacement, and thus reducing the airtightness of the ventilation device, affecting the reliability of the test results.

[0007] (5) When the ventilation device is in operation for a long time, dust, gas condensate residues, filter adhesive and other impurities may accumulate on the inner surface, which may interfere with the test background. Manually cleaning the ventilation device after each operation is labor-intensive, some dead corners are difficult to clean thoroughly, there are toxic and harmful substances, wear on the inner wall, and damage to precision equipment. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a self-cleaning flow equalization ventilation device for evaluating chemical filters.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a self-cleaning flow equalization ventilation device for chemical filter evaluation, comprising a filter section to be tested, a fan conversion section, and a fan. The front end of the filter section to be tested is sequentially provided with a pre-filtration section, a pre-mixing conversion section, a mixing chamber, and a post-mixing conversion section. The inlet of the pre-filtration section serves as an air inlet, and the outlet is connected to the front end of the mixing chamber through the pre-mixing conversion section. The interior of the mixing chamber serves as a mixing section for air and target gas. The rear end of the mixing chamber is connected to the filter section to be tested through the post-mixing conversion section. The mixing chamber includes a hollow first cylinder, and the post-mixing conversion section includes a hollow second cylinder. The hollow first cylinder and the hollow second cylinder are connected by multiple variable diameter sections. A target gas inlet pipe is connected to the hollow first cylinder, and a flow guiding mechanism, a cleaning ventilation mechanism, and a filtration mechanism are provided inside. A cleaning ventilation mechanism is also provided inside the hollow second cylinder.

[0010] Furthermore, the pre-filtration section includes a square enclosed frame and a multi-effect composite filter therein, in which different filter media with different performance are wrapped by non-woven fabric and connected face-to-face and folded by adhesive dotting.

[0011] Furthermore, the hollow first cylinder and the hollow second cylinder are interconnected by a large-to-small diameter transition and a small-to-expanding diameter transition. The top and end diameter ratio of the large-to-small diameter transition is 1.5-4, and the small-to-expanding diameter transition consists of a small cylinder and multiple stages of expanding diameter transitions, with the angle between adjacent transition wall surfaces and the central axis increasing sequentially.

[0012] Furthermore, the hollow first cylinder includes a first cylindrical shell, on which a target gas inlet is provided. The target gas inlet is connected to the target gas inlet pipeline, and a flow meter is provided on the target gas inlet pipeline. Two or more adjacent target gas inlets are merged into one pipeline and the same flow meter controls the gas intake.

[0013] Furthermore, the flow guiding mechanism consists of guide vanes, the number of which is not less than the number of target gas inlets. These vanes rotate along the connection point on the inner wall of the first cylindrical housing, and the angle between the guide vanes and the wall of the first cylindrical housing ranges from 0.01 to 0.12° / m. -3 ·h.

[0014] Furthermore, the cleaning ventilation mechanism is a perforated mesh, which mainly consists of a windward panel, an air outlet panel, perforated channels, windward mounds, air outlet mounds, an air inlet, an air outlet, an inlet, an outlet, a gas generator, a windward generator, an air outlet generator, and a cavity. The windward panel and the air outlet panel form a cavity with the inner wall of the cylindrical mixing chamber. Windward and air outlet openings are respectively provided on the windward and air outlet panels. A portion of the windward and air outlet openings are connected to perforated channels for ventilation, while the other portion of the windward and air outlet openings are equipped with windward and air outlet mounds. A windward generator and an air outlet generator are provided between the corresponding windward and air outlet mounds. The windward and air outlet generators are installed on both sides of the gas generator. The gas generator is connected to the air inlet and the air outlet. The inlet and outlet are connected to the cavity and are used to introduce clean liquid or dry gas into the cavity.

[0015] Furthermore, the windward and exhaust hills are cones with a through hole at the top of their shells, an S-shaped side, and an arc-shaped end that connects to the edge of the opening. The windward and exhaust generators seal the hills when they are in a gas-filled state.

[0016] Furthermore, the filtration mechanism includes a pre-filter and a metal-based inorganic mesh.

[0017] Furthermore, the primary filter is a curved mesh with a thickness of 10-20mm and a 5-15° bulge facing the wind; the metal-based inorganic mesh is a metal-based foam aggregate with a surface covered by a combination of two or more of ceramics, polymers, and carbon materials.

[0018] Furthermore, the test area of ​​the filter section to be tested shall accommodate at least one chemical filter, and the side shall be provided with a double door, and the filter shall be installed and removed by sliding along the bottom rail. The exhaust gas treatment area of ​​the filter section to be tested shall accommodate at least one filter screen. At least one particulate matter removal filter screen shall be provided between the fan conversion section and the fan.

[0019] The beneficial effects of this invention are as follows:

[0020] (1) The target gas is regulated by multiple flow meters and enters through multiple channels to improve the safety of the initial mixing of the gas. The guide vanes can further divert each channel of gas to accelerate dispersion and dilution. There is no need to increase the ambient humidity or reduce the temperature, so as to achieve the purpose of safe and uniform flow over a short distance.

[0021] (2) The primary filter in the mixing chamber serves to remove particulate matter and equalize the flow. Its curved design provides better dispersion for the concentrated airflow along the central axis. The metal-based inorganic mesh has a large porosity, which can gently and with low pressure loss homogenize the airflow.

[0022] (3) The design of the conical hill body, the transition connection between the opening and the hill body and the hole channel, and the plum blossom hole in the hill mesh of the mixing chamber can guide the flow, reduce resistance, and achieve high-efficiency flow equalization, maintain a long service life, reduce the requirements for the fan head, and save energy and reduce carbon emissions.

[0023] (4) The metal-based inorganic mesh in the mixing chamber is covered with inorganic corrosion-resistant materials such as ceramics, polymers, and carbon materials, which can slow down the corrosion, reduce the replacement frequency, and ensure the cleanliness of the airflow.

[0024] (5) The conical hill body of the hill mesh can effectively guide the flow, reduce the impact of airflow on the mesh, and thus reduce the probability of corrosion.

[0025] (6) The hill-shaped perforated mesh in the mixing chamber can clean the ventilation device in time, is corrosion-resistant and impact-resistant, can be sealed without disassembly, and ensures that the device is clean and the background concentration meets the standards, protecting the precision equipment inside the device and extending its service life.

[0026] (7) The large circle to small circle diameter change is treated with nitriding and molybdenum oxide spraying, which can effectively protect against corrosion and improve the service life of the ventilation device and the accuracy of test results.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the ventilation device structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the ventilation device of the present invention;

[0030] Figure 3 This is a schematic diagram of the overall mixing chamber of the present invention;

[0031] Figure 4 This is a schematic diagram of the interior of the mixing chamber of the present invention;

[0032] Figure 5 This is a schematic diagram of the mixed-granary hill-shaped perforated mesh of the present invention;

[0033] Figure 6 This is a schematic diagram of the explosion of the mixed-structure perforated mesh in the hilly area according to the present invention.

[0034] The diagram is labeled as follows: 1-Pre-filtration section, 2-Pre-mixing conversion section, 3-Mixing chamber, 31-Hollow first cylinder, 32-Large circle to small circle diameter changer, 33-Small circle to enlarged circle diameter changer, 34-Hollow second cylinder, 311-First cylinder shell, 312-Target gas inlet, 313-Inlet pipe, 314-Flow meter, 315-Guide vane, 316-First hill perforated mesh, 31601-Inlet, 31602-Outlet, 31603-Windward panel, 316031-Windward opening, 31604-Outlet panel, 316041-Outlet opening, 31605-Windward hill, 316051-Hill opening, 31 6052-S-type housing, 31606-outlet hill body, 31607-gas generator, 316071-airflow generator, 316072-gas filling, 316073-outlet generator, 31608-channel, 31609-cavity, 31610-inlet, 31611-vent, 317-primary filter, 318-metal-based inorganic mesh, 331-small cylinder, 332-first-stage expansion and diameter change, 333-second-stage expansion and diameter change, 334-third-stage expansion and diameter change, 341-second hill mesh, 342-second cylindrical housing, 4-mixing conversion section, 5-filter section to be tested, 6-fan conversion section, 7-fan. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] Please see Figure 1-6 A self-cleaning flow equalization ventilation device for evaluating chemical filters includes a pre-filtration section 1, a pre-mixing conversion section 2, a mixing chamber 3, a post-mixing conversion section 4, a filter section to be tested 5, a fan conversion section 6, and a fan 7.

[0037] The pre-filtration section 1 includes a square enclosed frame and a pre-filter within it. The mixing chamber 3, parallel to the pre-filtration section 1, is connected by a pre-mixing conversion section 2 with a variable diameter. The mixing chamber 3 is composed of a hollow first cylinder 31, a large-to-small-circle variable diameter section 32, a small-to-expanding-circle variable diameter section 33, and a hollow second cylinder 34. The hollow first cylinder 31 includes a first cylindrical shell 311, a target gas inlet 312, an inlet pipe 313, a flow meter 314, guide vanes 315, a first hill-shaped perforated mesh 316, a primary filter 317, and a metal-based inorganic mesh 318. The hollow second cylinder includes a first cylindrical shell 342, which has a second hill-shaped perforated mesh 341 inside. The end of the mixing chamber 3 away from the pre-filter 1 is connected to a test filter section 5 via a post-mixing conversion section 4. The test filter section 5 includes a test area and an exhaust gas treatment area. A fan conversion section 6 with a variable diameter is provided near the exhaust gas treatment area, and a fan 7 is connected to its end.

[0038] Preferably, the pre-filtration section 1 comprises a multi-effect composite filter, in which different filter media of varying effectiveness are wrapped in non-woven fabric and connected face-to-face and folded by adhesive dispensing. Preferably, the filter media contains components for removing acidic, alkaline, TVOC, and small molecule gaseous pollutants. Preferably, the filter media is composed of at least one or a combination of activated carbon fibers, activated carbon particles, resin particles, and molecular sieve particles. Preferably, at least one layer of the non-woven fabric is meltblown non-woven fabric. The pre-filtration section can effectively remove particulates and gaseous molecules from the inlet pollutants and prevent leakage of the target gas due to initial turbulence in the mixing chamber.

[0039] Preferably, the target gas inlets 312 in the mixing chamber 3 are connected to inlet pipes 313 respectively. Two or more adjacent inlets 312 are merged into one pipe and controlled by the same flow meter 314. The airflow of the mixing chamber 3 as a whole is regulated by multiple flow meters 314. Preferably, there are 4-6 target gas inlets 312. Two adjacent inlets 312 are merged into one inlet, and the distance between the merging port and the two inlets 312 is equal. Preferably, the inlets 312 can protrude into the inner wall of the mixing chamber 3, forming an angle of 60-85° with the root of the guide vane 315, further optimizing the airflow direction. Multiple inlets can reduce the concentration of the target gas at the inlet, accelerate the dilution process with air, and make the target gas uniformly and stably dispersed in the cavity.

[0040] Preferably, the number of guide vanes 315 is not less than the number of target gas inlets 312, and they can rotate along the connection point on the inner wall of the first cylindrical shell 311. The rotation angle is determined by the airflow volume, and the angle between the vanes 315 and the wall of the first cylindrical shell 311 ranges from 0.01 to 0.12° / m-3·h. Preferably, the number of guide vanes 315 is 1 or 2 times the number of inlets 312, and the midpoint or 1 / 3 position of the vanes 315 is directly opposite the inlets 312. Preferably, the distance between the connection point of the guide vanes 315 and the wall of the shell 311 and the inlets 312 is 10-100 mm, more preferably 15-40 mm. If the distance is too large, the guiding effect will be weakened; if the distance is too small, it can cause severe corrosion and impact damage to the guide vanes 315. Preferably, the airflow volume is 500 m³ / h. 3 At a speed of 6000 m³ / h, the angle between blade 315 and the wall of the first cylindrical shell 311 is 45-60°, and the aspect ratio of blade 315 is 30-60; the air volume is 6000 m³ / h. 3At a flow rate of 315 m / h, the included angle of the blade 315 is 75-85°, and the aspect ratio of the blade 315 is 15-30. The guide vane 315 can also form an acute angle with the central axis of the housing 311, with the included angle being 70-89° at high airflow rates and decreasing to 50-60° at low airflow rates. The guide vane 315 can also be curved, bulging from the connection with the wall towards the air inlet and concave near the central axis of the housing 311, or only the latter. The curved surface can effectively prevent mutual interference or friction caused by the vibration of the blade 315 under stress, thus extending the service life of the blade 315.

[0041] Preferably, the hill-shaped perforated mesh mainly consists of a windward panel 31603, an air outlet panel 31604, a perforated channel 31608, a windward hill body 31605, an air outlet hill body 31606, an air inlet 31601, an air vent 31611, an inlet 31610, an outlet 31602, an air generator 31607, a windward generator 316071, an air outlet generator 316073, and a cavity 31609. A cavity is formed between the windward panel 31603, the air outlet panel 31604, and the cylindrical inner wall of the mixing chamber. Windward openings 316031 and air outlets are respectively provided on the windward panel 31603 and the air outlet panel 31604. The opening 316041 has a ventilation channel 31608 connecting a portion of the windward opening 316031 and the air outlet opening 316041. The other portion of the windward opening 316031 and the air outlet opening 316041 are equipped with a windward mound 31605 and an air outlet mound 31606. A windward generator 316071 and an air outlet generator 316073 are provided between the corresponding windward mound 31605 and air outlet mound 31606. The windward generator 316071 and the air outlet generator 316073 are installed on both sides of the gas generation and the gas generation is connected to the gas inlet 31601 and the gas outlet 31611.

[0042] Preferably, the perforated mesh at the front and rear ends is consistent. The air intake and exhaust panels, as well as the perforated body, are made of stainless steel, PFA, or PTFE.

[0043] Preferably, the openings on the windward or exhaust side are arranged at 45° or 60°, more preferably 60° to increase porosity. The hill-like structures are also distributed at 60° to the openings, filling the center of the openings. The corresponding openings on the inlet and outlet sides connect to the channel with an arc surface to ensure a smooth connection surface, with a polishing grade of BA.

[0044] Furthermore, the hill-shaped body is conical, with an S-shaped shell 31652 on its sides at an inclination angle of 60-80°. Its ends are arc-shaped and connect to the edge of the opening. An opening is located at the top of the hill-shaped body. The generator (ultrasonic probe) is placed into the cavity along the opposite hill-shaped body and, in the closed state, seals the hill-shaped body to prevent air intake. Airflow passes directly through the opening or is introduced into the pore channel along the S-shaped shell of the hill-shaped body. This allows for adjustment of the airflow direction, reduction of turbulence, and effective reduction of pressure loss in the hill-shaped pore network, while also ensuring efficient flow uniformity.

[0045] Preferably, the width of the cavity 31609 is 3-50mm, preferably 30mm, which ensures sufficient fluid inside the cavity, guarantees outlet pressure and range, and also shortens the airflow path to avoid significant pressure loss. Water or alcohol is introduced into the cavity 31609 and ultrasonically sprayed into the ventilation device for cleaning; or 30-35% hydrogen peroxide is introduced and atomized by the generator before entering the ventilation device for sterilization; or compressed air is introduced and its flow rate is controlled by the generator before entering the ventilation device for drying.

[0046] The general working process of the hill perforated mesh is as follows: Before the ventilation device is put into operation, gas is injected through the air inlet 31601 and the air outlet 31611 is closed. The gas filling 316072 is filled with gas and is in an inflated state. The wind generators 316071 and 316073 on both sides of the gas filling 316072 move towards the windward hill body 31605 and the air outlet hill body 31606 respectively, until they are close to the S-shaped shell 316052. The openings on the windward and air outlet surfaces do not allow gas to pass through, thus achieving the sealing of the hill body.

[0047] During the cleaning phase, with the ventilation system not operating, the inflation port 31601 is closed, and the vent 31611 is opened to release the gas from the inflation gas 316072. The inflation gas 316072 contracts, and the generators on both sides of the inflation gas 316072 separate from the S-shaped housing. Liquid in the cavity 31609 submerges the gap between the generator and the S-shaped housing. The generator circuitry is located inside the inflation gas 316072 and is protected by the gas inside to prevent moisture and water ingress.

[0048] Preferably, the primary filter 317 is a G3-G4 filter with a thickness of 10-20mm, a curved surface, and a 5-15° bulge facing the wind.

[0049] Preferably, the metal-based inorganic mesh 318 is a metal-based foam aggregate, with a surface coated with ceramics, polymers, carbon materials, or a combination of two or more. Further, the metal base is nickel-based, copper-based, or stainless steel, and the coating is a combination of one or more of ceramics, PTFE, PFA, carbon nanotubes, graphene, molybdenum oxide, etc. Alternatively, it can be a stainless steel base aggregate, which is nitrided and then coated with resin. Preferably, the pore size of the metal-based inorganic mesh 318 is 0.1-8 mm, more preferably 2-6 mm (80%); the porosity is 98-99.5%; and the thickness is 5-20 mm, preferably 5-10 mm. This metal-based inorganic mesh 318 has the characteristics of high porosity, low pressure loss, and corrosion resistance. As a flow equalization mesh before diameter change, it can reduce the backflow caused by airflow compression.

[0050] Preferably, the top-to-bottom diameter ratio of the large-circle to small-circle transition diameter 32 is 1.5-4. Further, a guide ring can be provided inside the large-circle to small-circle transition diameter 32, and its inner wall can be treated with nitriding or molybdenum oxide powder spraying to enhance impact and wear resistance. The small-circle to expanding-circle transition diameter 33 consists of a small cylinder and multiple stages of expanding-circle transition diameters, with the angle between adjacent transition diameter walls and the central axis increasing sequentially. Preferably, the expanding-circle transition diameters are divided into 1-5 stages, more preferably 3 stages, with angles to the central axis of 25-35°, 35-40°, 45-55°, more preferably 30°, 40°, and 55°. Further, guide vanes or guide rings can also be provided in the small-circle to expanding-circle transition diameter 33, with the angle between them and the inner wall of the small-circle to expanding-circle transition diameter 33 gradually increasing along the airflow direction.

[0051] Preferably, the test area of ​​the filter section 5 can accommodate at least one chemical filter, with double doors on the side and easy installation and removal of the filter via a bottom sliding rail. The exhaust gas treatment area can accommodate at least one filter screen, preferably a filter screen with a thickness of 200mm or more, or a filter screen filled with adsorbent particles.

[0052] Preferably, at least one particulate filter can be installed between the fan conversion section 6 and the fan 7 to prevent cavitation and perforation of the fan blades during high-speed operation.

[0053] The operation process of the ventilation device is as follows:

[0054] 1) Install the chemical filter to be tested in the test area of ​​filter section 5.

[0055] 2) Turn on fan 7 and adjust the airflow to the set value.

[0056] 3) Start the target gas supply, adjust the flow rate of each inlet 312 via flow meter 314, and adjust the rotation angle of the guide vanes 315.

[0057] 4) Detect parameters such as upstream and downstream concentration, air volume, and pressure loss of the filter under test, and calculate the filtration efficiency.

[0058] In actual production, as an example, the pre-filtration section 1 is equipped with a composite filter containing resin, activated carbon fiber, and molecular sieve filter media for removing acid, alkali, TVOC, and acetone. During air blowing, the concentrations of all gases in the mixing chamber 3 were found to be below the detection limit. The mixing chamber has an inner diameter of Φ600mm and six air inlets 312, connected in pairs, with three flow meters 314 controlling the air intake. There are six blades 315, with an angle of 78° to the wall of the first cylindrical shell 311, a length-to-diameter ratio of 27, and an angle of 81° to the central axis of the shell 311, recessed near the central axis. The openings on the windward and exhaust sides are arranged at 60° intervals, the hill-shaped inclination angle is 75°, and an ultrasonic atomization probe is built-in. The primary filter 317 is a G4 filter with a thickness of 17mm, a curved surface, and a 13° convexity on the windward side. The 318 metal-based inorganic mesh has a stainless steel base with a pore size of 5mm (80%), nitrided aggregate, and carbon nanotubes sprayed on. The top and end diameter ratio of the 32 large-to-small circle diameter change is 3.2, and the diameter expansion is 30°, 41°, and 57° respectively.

[0059] The filter section under test, section 5, is equipped with a 595x595x210mm pleated chemical filter at 3186m. 3 The initial removal efficiency for 10.50 ppm ammonia was measured at a flow rate of / h, reaching 99.3%, with a pressure drop of 55 Pa. The ammonia concentration at each point (312) of the target gas inlet in mixing chamber 3 was 1.73-1.76 ppm, with a variance of 0.012 ppm. Using a 16-point method, the center wind speed and concentration of each area were measured. The ammonia concentration at a position 200 mm from the filter inlet was 10.495-10.512 ppm, with a variance of 0.0054 ppm; the wind speed was 2.49-2.51 m / s, with a variance of 0.0056 m / s. The guide vanes 315, the perforated mesh, the primary filter 317, and the metal-based inorganic cover 318 were removed. Only one ammonia gas was introduced into the duct. The ammonia concentration at a position 200mm from the filter inlet was measured to be 10.007-10.952 ppm, with a variance of 0.2332 ppm; the air velocity was 2.39-2.59 m / s, with a variance of 0.0609 m / s. This ventilation device significantly improves the flow uniformity compared to non-uniform flow, greatly enhancing the mixing uniformity of the target gas and air. After three months of continuous use, the ventilation device was cleaned sequentially by passing water, hydrogen peroxide, and compressed air through the perforated mesh. Random sampling of the inner wall of the ventilation device revealed no bacteria or viruses. Furthermore, during air blowing, the concentrations of acid, alkali, and VOC gases in all parts were below the detection limit. The self-cleaning system is convenient and easy to maintain, and provides excellent cleaning for the ventilation device.

[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the scope of protection of the present invention in any way, and all technical solutions obtained by equivalent substitution or other means fall within the scope of protection of the present invention.

[0061] All parts not covered in this invention are the same as or can be implemented using existing technologies.

Claims

1. A self-cleaning flow equalization ventilation device for evaluating chemical filters, comprising a filter section to be tested, a fan switching section, and a fan, characterized in that, The front end of the filter section to be tested is sequentially provided with a pre-filtration section, a pre-mixing conversion section, a mixing chamber, and a post-mixing conversion section. The inlet of the pre-filtration section serves as an air inlet, and the outlet is connected to the front end of the mixing chamber through the pre-mixing conversion section. The interior of the mixing chamber serves as a mixing section for air and target gas. The rear end of the mixing chamber is connected to the filter section to be tested through the post-mixing conversion section. The mixing chamber includes a hollow first cylinder, and the post-mixing conversion section includes a hollow second cylinder. The hollow first cylinder and the hollow second cylinder are connected by multiple variable diameter sections. A target gas inlet pipe is connected to the hollow first cylinder, and a flow guiding mechanism, a cleaning ventilation mechanism, and a filtration mechanism are provided inside. A cleaning ventilation mechanism is also provided inside the hollow second cylinder. The cleaning ventilation mechanism is a perforated mesh, which consists of a windward panel, an air outlet panel, perforated channels, windward mounds, air outlet mounds, an air inlet, an air outlet, an inlet, an outlet, a gas generator, a windward generator, an air outlet generator, and a cavity. The windward panel and the air outlet panel form a cavity with the inner wall of the cylindrical mixing chamber. Windward openings and air outlet openings are respectively opened on the windward panel and the air outlet panel. A portion of the windward openings and the air outlet openings are connected to perforated channels for ventilation. Another portion of the windward openings and the air outlet openings are equipped with windward mounds and air outlet mounds. A windward generator and an air outlet generator are provided between the corresponding windward mounds and the air outlet mounds. The windward generator and the air outlet generator are installed on both sides of the gas generator. The gas generator is connected to the air inlet and the air outlet. The inlet and the outlet are connected to the cavity and are used to introduce clean liquid or dry gas into the cavity. The windward and exhaust hills are cones with a through hole at the top of their shells, an S-shaped side, and an arc-shaped end that connects to the edge of the opening. The windward and exhaust generators seal the hills when they are in a gas-filled state.

2. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 1, characterized in that, The pre-filtration section includes a square enclosed frame and a multi-effect composite filter therein. In the multi-effect composite filter, different filter media with different performance are wrapped with non-woven fabric and connected face-to-face by adhesive dotting and folding.

3. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 1, characterized in that, The hollow first cylinder and the hollow second cylinder are connected to each other by a large circle turning into a small circle and a small circle turning into an expanded circle. The top and end diameter ratio of the large circle turning into a small circle is 1.5-4. The small circle turning into an expanded circle consists of a small cylinder and multiple stages of expanded circle, and the angle between the adjacent diameter change wall and the central axis increases sequentially.

4. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 1, characterized in that, The hollow first cylinder includes a first cylindrical shell, on which a target gas inlet is provided. The target gas inlet is connected to the target gas inlet pipeline, and a flow meter is provided on the target gas inlet pipeline. Two or more adjacent target gas inlets are merged into one pipeline and the same flow meter controls the gas intake.

5. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 4, characterized in that, The flow guiding mechanism consists of guide vanes, the number of which is not less than the number of target gas inlets. These vanes rotate along the connection point on the inner wall of the first cylindrical shell, and the angle between the guide vanes and the wall of the first cylindrical shell ranges from 0.01 to 0.12 ° / m. -3 .h 6. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 1, characterized in that, The filtration mechanism includes a pre-filter and a metal-based inorganic mesh.

7. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 6, characterized in that, The primary filter is a curved mesh with a thickness of 10-20mm and a 5-15° bulge facing the wind; the metal-based inorganic mesh is a metal-based foam aggregate with a surface covered by a combination of two or more of ceramics, polymers, and carbon materials.

8. The self-cleaning flow equalization ventilation device for chemical filter evaluation according to claim 1, characterized in that, The test area of ​​the filter section to be tested shall accommodate at least one chemical filter. The side is equipped with a double door and the filter can be installed and removed by sliding it through the bottom rail. The exhaust gas treatment area of ​​the filter section to be tested shall accommodate at least one filter screen. At least one particulate matter removal filter screen shall be installed between the fan conversion section and the fan.

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