Outdoor air purifier

Abstract

To provide an outside air cleaning device capable of generating highly clean compressed air by removing oil mist, oil vapor, and VOC on an intake side without reducing compression efficiency in an oil-free air compressor.SOLUTION: This outside air cleaning device is provided in an intake part of an oil free type air compressor, and has an intake filter, and adopts a means for removing oil mist, oil vapor and a volatile organic compound of air passing through the intake part of the intake filter.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an outside air purification device, and more particularly to a technology for an outside air purification device that improves the oil cleanliness rating of an oil-free air compressor. [Background technology]

[0002] Conventionally, when compressed air is used for food, medicine, etc., oil-free air compressors are often used. However, if the outside air contains oil mist, oil vapor, or VOCs, even if an oil-free air compressor is used, compressed air containing oil and other contaminants will still be generated, which can be a problem. Therefore, there was a need for technology to remove oil mist, oil vapor, and VOCs from the intake side of oil-free air compressors without reducing the compression efficiency of the compressed air.

[0003] To address these problems, various techniques have been proposed. For example, a compressor intake filter (see Patent Document 1) has been proposed and is a known technique. More specifically, this compressor intake filter has a structure that removes moisture and carbon dioxide. However, there is no mention of the compressor being oil-free or of removing oil from the air, and the above-mentioned problems are not solved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-113914 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above problems, an object of the present invention is to provide an outside air purification device that can remove oil mist, oil vapor, and VOCs from the intake side of an oil-free air compressor to produce highly clean compressed air without reducing compression efficiency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides an outside air purification device provided in an intake section of an oil-free air compressor, the outside air purification device comprising an intake filter, The intake filter is divided into a plurality of blocks, each block being composed of a plurality of detachable cartridges, and each cartridge is configured to have one type of adsorbent material alone or a mixture of a plurality of adsorbents among HEPA filters, activated carbon, amine, polypropylene fiber, and a mixture of natural polyphenols and catalysts, and the adsorbent materials of the cartridges are different for each block, and the intake filter is configured as follows: Measures are taken to remove oil mist, oil vapor, and volatile organic compounds from the air passing through the intake section.

[0007] The present invention also employs an intake filter that removes oil mist, oil vapor, and volatile organic compounds, thereby ensuring that the cleanliness of the air passing through the intake section is equivalent to Class 0 of the ISO 8573-1 compressed air standard.

[0008] Furthermore, the present invention provides an intake filter that reduces the oil mist, oil vapor and volatile organic compound content by at least 10 times.

[0009] Furthermore, the present invention employs a means in which a dust filter is disposed in front of the intake filter.

[0010] Furthermore, the present invention employs a means for making the pressure loss of the intake filter 6 kPa or less.

[0012] Furthermore, the present invention employs a means in which the intake filter is capable of adsorbing carbon dioxide. [Effects of the Invention]

[0016] The outside air purification device of the present invention can remove oil mist, oil vapor, and VOCs from the intake side of an oil-free air compressor without reducing the compression efficiency of the compressed air, making it possible to generate highly clean compressed air regardless of the installation environment. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an explanatory diagram showing a compressed air circuit around an air compressor including an outside air purification device according to the present invention. [Figure 2] 1 is a perspective view illustrating a cartridge of an intake filter of an outside air purification device according to the present invention. [Figure 3] 1 is a side view illustrating replacement of an intake filter cartridge of an outside air purification device according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] The greatest feature of the outside air purification device of the present invention is that it improves the performance of an oil-free air compressor. Hereinafter, an embodiment of an outside air purification device according to the present invention will be described with reference to the drawings. The overall configuration and the configuration of each part of the outdoor air purification device shown below are not limited to the examples described below, but can be modified as appropriate within the scope of the technical concept of the present invention, i.e., within the scope of shapes, dimensions, structures, etc. that can achieve the same functional effects.

[0019] The present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing a compressed air circuit around an air compressor including an outdoor air purification device according to the present invention, where (a) is an example of a stand-alone air compressor, and (b) is an example of a packaged air compressor. Figure 2 is an oblique view illustrating the cartridge of the intake filter of the outdoor air purifying device of the present invention, where (a) is a schematic diagram showing the shape of the outdoor air purifying device when in use, and (b) is a schematic diagram showing how to replace the cartridge of the intake filter of the outdoor air purifying device. FIG. 3 is a side view illustrating replacement of the cartridge of the intake filter of the outside air purification device according to the present invention, and (a), (b), and (c) show an example of the procedure for replacing part of the cartridge.

[0020] The outside air purification device 1 is intended to prevent the performance related to the cleanliness class of an oil-free air compressor from being affected by the cleanliness of the outside air around the compressor. Oil-free air compressors are designed to supply clean, oil-free air by using no oil in the air compression mechanism. However, depending on the installation environment of the compressor, for example, if the installation location is prone to oil mist, the compressor will draw in and compress that air, and as a result, will supply compressed air containing oil, even if no oil is produced by the compressor itself. By installing a special filter that captures oil mist, oil vapor, and VOCs (volatile organic compounds) before the air intake of the air compressor, the oil-free air compressor can still provide the clean, high-quality compressed air it is known for, even under adverse environmental conditions.

[0021] The outside air purification device 1 is equipped with an intake filter 10 that is provided in the intake section of an oil-free air compressor, and is placed in front of the intake port of the oil-free air compressor to increase the purity of the air entering the compressor. Removes oil mist, oil vapor, and volatile organic compounds from the air passing through the intake. The outside air purification device 1 is disposed in front of an air compressor 50, an air dryer 60, and an air tank 61 that constitute a compressed air pressure circuit.

[0022] First, the air compressor 50, the air dryer 60, and the air tank 61 will be described with reference to FIG. 1(a). The air compressor 50 generates compressed air. The compressor in this embodiment is an oil-free air compressor. An oil-free air compressor is one that does not use any oil for lubrication of the compressor when compressing air. By not using oil, no oil gets mixed into the compressed air, so cleaner air can be generated. Because the air is highly clean, it is used in the food industry, medical industry, and other industries. The air dryer 60 removes moisture contained in the air compressed by the air compressor 50. Moisture removal can be achieved by using a hollow membrane or by lowering the temperature of the air to cause condensation for removal. In this embodiment, a refrigeration-type air dryer is used. Refrigeration type air dryers are installed in the discharge air line of an air compressor to suppress condensation and create air that generates as little condensate as possible. By lowering the air temperature to a freezing level, the water vapor in the air is condensed inside the dryer and separated as condensate. The air tank 61 is a tank that temporarily stores compressed air. The presence of the air tank 61 makes it possible to stabilize the pressure of the compressed air used. A drain trap 62 for discharging drainage, which is unnecessary moisture, is disposed in both the air dryer 60 and the air tank 61. The drainage collected in the drain trap 62 is discharged as appropriate. As shown in FIG. 1(b), the air compressor 50 may also be configured as a packaged type in which the air compressor 50 and air dryer 60 are integrated. In the packaged type, the air compressor 50 and air dryer 60 are housed in a single housing, so when installing the outdoor air purification device 1, it is possible to fix the air compressor 50 directly to the side of the housing of the packaged compressor. In this way, the cleanliness of the air compressor 50 can be improved without taking up space for the outdoor air purification device 1.

[0023] By using an oil-free air compressor, highly clean, oil-free air should be passed through the air compressor 50, air dryer 60, and air tank 61. However, if the air drawn into the air compressor 50 itself contains impurities that lower its cleanliness, the cleanliness of the air generated by the air compressor 50 will also be reduced as a result. Therefore, by providing an intake pipe 51 at the intake port 52 of the air compressor 50 and placing an outside air purification device 1 at the end of the intake pipe 51, the cleanliness of the air entering the air compressor 50 is increased, making it possible to generate compressed air that matches the original performance of the air compressor 50. Furthermore, by installing the outside air purification device 1, the noise of the compressor can be reduced.

[0024] The outside air purification device 1 includes an intake filter 10 and a dust filter 40. An exhaust port 12 of the intake filter 10 is connected to an intake pipe 51 of the air compressor 50, and a dust filter 40 is connected to an intake port 11 of the intake filter 10. The intake filter 10 purifies the air passing through it, and the dust filter 40 reduces clogging of the intake filter 10 by removing relatively large impurities. The intake filter 10 is made up of a first block portion 13 and a second block portion 14 and is covered with a housing 16 . The adsorption material of the first block portion 13 and the adsorption material of the second block portion 14 are different adsorption materials. do. In this embodiment, the trapping material of the first block portion 13 is polypropylene fiber, and the trapping material of the second block portion 14 is a HEPA filter. Outside air enters the housing 16 through the intake port 11 of the intake filter 10, and first, oil mist and oil vapor are captured by the polypropylene fiber of the first block part 13. Next, oil mist, oil vapor, and VOCs with particle diameters of about 1 um are captured by the HEPA filter of the second block part 14. The first block section 13 and the second block section 14 give the air a cleanliness rating of 0. The purified air is discharged from the exhaust port 12, passes through the intake pipe 51 of the air compressor, and enters the air compressor 50 through the intake port 52. This series of operations allows the oil-free air compressor to perform at its full potential even when the air contains oil mist or other contaminants.

[0025] Each block is made up of a first block cartridge 20 and a second block cartridge 30, and each block is made up of a plurality of cartridges. A collection material is placed inside the cartridge, which is fixed by a cartridge holder 15 inside a housing 16 (FIG. 2(a)). Furthermore, when replacing the cartridge, it can be easily replaced by pulling it out from the top of the housing, as shown in Figure 2(b).

[0026] The dust filter 40 is disposed in front of the housing 16 of the intake filter 10. The dust filter 40 is a filter that removes relatively large dust particles from the air. By providing the dust filter 40, clogging of the intake filter 10 can be reduced, and the effectiveness of the intake filter 10 can be maintained for a longer period of time. The dust filter 40 may be provided in a single unit as shown in FIG. 1(a), or in the case where there is a large amount of floating dust, a plurality of dust filters may be provided as shown in FIG. 1(b). A cyclone filter may also be used. For example, to convert air at atmospheric pressure (0.1 MPa) into compressed air at 0.7 MPa, the amount of intake air per unit volume must be increased by about seven times, so the flow rate of the air entering the intake filter 10 also becomes large. A cyclone filter is effective at high flow rates, so by placing a cyclone filter in front of the intake filter 10, dust can be removed effectively. Furthermore, by separating the moisture in the air, it is possible to prevent the intake filter from becoming clogged with moisture.

[0027] If the air compressor 50 is guaranteed to meet ISO8573-1 cleanliness grade 0, the total oil concentration must be 0.01 mg / m3 or less, and the particle count must be 10 or less per cubic meter for particles with a particle size (um) of 1.0 to 0.5. These particles contain VOCs (volatile organic compounds).

[0028] In this embodiment, the size of the oil mist is 1 to 10 μm, and the size of the oil vapor is less than 1 μm. Oil mist and oil vapor are generated when lubricating oil used in machine tools is dispersed during machine operation, resulting in fine particles of oil floating in the air. It can also be generated from equipment that contains oil, other than machine tools. VOC is a general term for chemical substances called volatile organic compounds. They are easily volatile and become gases in the atmosphere. They are also one of the causes of photochemical oxidants and PM2.5, and affect cleanliness. VOCs include tiny particles with a diameter of 10 μm or less that float in the air, and inhalation of a certain level or more can have an effect on the respiratory system, etc. To remove VOCs, filters that capture particles up to a few microns in size or filters that remove them by reacting them with natural polyphenols using a catalyst are used.

[0029] A HEPA filter is a high-performance particulate air filter that can capture very small particles in the air, such as pollen, dust, and viruses. Under certain conditions, the particle collection rate is 99.97% or more for particles with a diameter of 0.3 μm. It has a high collection effect on oil mist, oil vapor, and VOCs. Polypropylene fiber is an aggregate of ultra-fine fibers made of polypropylene. Polypropylene can absorb oils and fats. By making it an aggregate of ultra-fine fibers, it can absorb even the smallest particles of oil and fat. If moisture or the like is contained in the air, the collection efficiency may decrease, so in some cases a moisture removal filter such as a cyclone may be added. One filter that removes VOCs from gases uses natural polyphenols and a catalyst. By reacting with aldehyde-type volatile organic compounds, a polymer is produced and retained within the filter. The mixture of multiple natural polyphenols and a catalyst agent can be made into granules or pellets, which can be easily handled as an element within a filter. Activated carbon is a material that adsorbs impurities in the air into the tiny pores on its surface. It can remove oil mist, oil vapor and VOCs from the air.

[0030] An example of the replacement work of the cartridge containing the adsorption material will be described with reference to FIG. When the intake filter 10 of the outdoor air purifying device 1 is used for a long period of time, particles accumulate in each cartridge, causing clogging and reducing the filter's performance. When the filter is made up of multiple cartridges, performance degradation often begins with the cartridge closest to the intake port. The case of replacing the first block cartridge 20 of the first block portion 13 will be described. First, pull out A, which is closest to the intake port with the most degraded performance (Figure (a)). Then, pull out the remaining B and C cartridges one by one and insert them into the previous slot (Fig. 3(b)). Cartridge B will be closest to the intake port, followed by cartridge C. A new cartridge, D, is inserted into the third slot from the intake port (Fig. 3(c)). With this configuration, when a plurality of cartridges are used, each cartridge can be used in the same manner, and therefore each cartridge can be used effectively.

[0031] The intake filter 10 of the outside air purification device 1 allows air at atmospheric pressure to pass through. The filter used in the compressed air circuit allows compressed air at a pressure of, for example, about 0.7 MPa to pass through. Therefore, unless the pressure loss of the filter is extremely high, it has little effect on the compressed air. However, in the case of an intake filter, the pressure of the air used is 0.1 MPa, so the impact of pressure loss is greater than in the compressed air circuit. In the compressed air circuit, the pressure loss of the activated carbon filter is 12 kPa. This value is more than 10% of the atmospheric pressure of 0.1 MPa, reducing compression efficiency. Therefore, by reducing the pressure in the intake filter to half that, 6 kPa or less, the reduction in compression efficiency can be reduced.

[0032] An example of use of the outdoor air purification device 1 will be shown. An oil-free air compressor does not generate oil or other contaminants, and if the outside air is of purity class 0, it will simply generate compressed air of purity class 0. Consider the case where an oil-free air compressor is used in a pharmaceutical or food factory, etc., where cleanliness class 1 or less is required. If the cleanliness class of the installation location is 0, the air generated by the compressor will also have a cleanliness class of 0, so there is no problem. If the air quality rating of the installation location is 1, the air produced by the compressor will have the same purity rating as the air in the installation location, 1. Therefore, the purity rating of the air entering the compressor must be 0. To reduce the cleanliness rating from 1 to 0, a filter must be used that reduces the amount of impurities by at least 10 times. In other words, the outside air purification device 1 has the ability to reduce the content of oil mist, oil vapor, and volatile organic compounds in the air passing through the intake section to at least one-tenth.

[0033] In this embodiment, the purpose is to remove oil mist, oil vapor, and VOCs, but carbon dioxide can also be reduced at the same time as removing these. A block for carbon dioxide adsorption is provided in the intake filter 10 of the outside air purification device 1, and a cartridge containing a collection material for carbon dioxide adsorption is provided. For example, a third block portion is provided, and the cartridge is used for carbon dioxide adsorption. Examples of the collection material include adsorbents such as amine compounds and lithium, and activated carbon. This configuration reduces carbon dioxide in the air while maintaining an air purity rating of 0, making it an environmentally friendly system.

[0034] In this embodiment, a case where one adsorption material is arranged in one cartridge will be described, but a plurality of adsorption materials may be mixed in one cartridge. For example, activated carbon and polypropylene fibers may be mixed and packed into the cartridge. In this way, it is possible to prepare a cartridge that is optimized for the installation environment.

[0035] In this way, the outside air purification device of the present invention can remove oil mist, oil vapor, and VOCs from the intake side of an oil-free air compressor without reducing the compression efficiency of the compressed air, making it possible to generate highly clean compressed air regardless of the installation environment.

[0036] Furthermore, by disposing a dust filter in front of the intake filter of the outside air purification device, clogging of the intake filter can be reduced, and the filter life can be extended.

[0037] Furthermore, by keeping the pressure loss of the intake filter at 6 kPa or less, it is possible to reduce pressure changes relative to low-pressure atmospheric air, and prevent a decrease in compression efficiency.

[0038] Furthermore, by using any of HEPA filters, activated carbon, amine, and polypropylene fibers as the collection material, oil and the like can be removed efficiently.

[0039] Furthermore, by being able to adsorb carbon dioxide, it is possible to contribute to improving the global environment while carrying out normal business operations.

[0040] Furthermore, since the intake filter of the outside air purifying device is made up of a plurality of detachable cartridges, each cartridge can be replaced or the like depending on its deterioration state.

[0041] Furthermore, by incorporating two of the following materials into one cartridge: HEPA filter, activated carbon, amine, and polypropylene fiber, more collection materials can be used, resulting in a more efficient outdoor air purification device.

[0042] Furthermore, the intake filter of the outdoor air purifier is divided into multiple blocks, and each block is made up of multiple cartridges, so that the number of cartridges and the type of adsorption material can be changed depending on the adsorption material, resulting in a more efficient outdoor air purifier. [Industrial Applicability]

[0043] The present invention is useful as a technology for increasing the cleanliness of oil-free air compressors, and can be used not only in fields such as food and pharmaceuticals, where cleanliness is particularly important, but also in any field that uses compressed air. Therefore, it is understood that the "outside air purification device" according to the present invention has great industrial applicability. [Explanation of symbols]

[0044] 1. Outdoor air purifier 10. Intake filter 11 Air intake 12 exhaust port 13 First Block 14 Second Block 15 Cartridge holder 16 Case 20 Cartridge for 1st block 30 Cartridge for second block 40 Dust filter 50 Air Compressor 51 Intake pipe 52 Air intake 53 Outlet 60 Air dryer 61 Air Tank 62 Drain trap

Claims

1. An outside air purification device provided in the intake section of an oil-free air compressor, Equipped with an intake filter, The intake filter is divided into a plurality of blocks, and each block is composed of a plurality of removable cartridges. One cartridge is configured to have one type of adsorption material alone or a mixture of multiple adsorption materials selected from the group consisting of a HEPA filter, activated carbon, amine, polypropylene fiber, and a mixture of natural polyphenols and a catalyst agent, arranged in one cartridge; The collection material of the cartridge is different for each block, The air intake filter is an outside air purification device that removes oil mist, oil vapor, and volatile organic compounds from the air passing through the air intake section.

2. The outside air purification device of claim 1, characterized in that the intake filter removes the oil mist, oil vapor, and volatile organic compounds, thereby making the cleanliness class of the air passing through the intake section equivalent to Class 0 of ISO 573-1 compressed air.

3. 2. The outside air purifying device according to claim 1, wherein the intake filter reduces the content of the oil mist, oil vapor, and volatile organic compounds in the air passing through the intake section by at least one-tenth.

4. 2. The outside air purification device according to claim 1, further comprising a dust filter disposed in front of the intake filter.

5. 2. The outside air purification device according to claim 1, wherein the pressure loss of the intake filter is 6 kPa or less.

6. 2. The outside air purification device according to claim 1, wherein the intake filter is capable of adsorbing carbon dioxide.

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