JPS6196342A - Air purifying method - Google Patents

Abstract

PURPOSE:To furnish a biologically clean room, in which the air polluted with fine particles, microorganisms and the like is purified, by a method wherein ultraviolet rays are irradiated to the polluted air or the air is turned into inert gas by enriching with nitrogen. CONSTITUTION:When the air is intended to be supplied to a clean room 1, firstly, both the outside air, grits containing in which is removed by a pre-filter 3, and the air, which is taken out of the clean room 1 through an air outlet 4, are sent by a fan 5 to an air conditioner 6 in order to be air-conditioned (to be controlled the temperature and humidity of the resultant air) and, after that, to be removed fine particles in the air with a filter 7 in order to be supplied to the clean room 1, resulting in keeping the cleanness of the room 1 at the level of the class 100,000. On the other hand, as for a working area, due to a clean booth 12 consisting of a fan 8, an ultraviolet-light irradiating unit 9, an electrostatic filter 10 and a transparent curtain 11, the cleanness on a work table 13 is kept at the level of the class 100. Fine particles including dead microorganisms are collected with the electrostatic filter 10.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air purification method for purifying indoor air.
In particular, the present invention relates to an air purification method suitable for use in air purification in biological clean rooms.

[Prior Art] This type of method can be roughly divided into (i) a mechanical filter type that uses mechanical introduction, and (ii) an electrostatic filter type that performs collection electrostatically.

Among these, the main components of method (i) are a fan and a filter, and a fine-mesh filter is used to improve cleanliness. This method generally has high dust collection efficiency, but also high pressure loss. For this reason, if the mesh of the filter is made coarser in an attempt to reduce the pressure of 1Ω, the dust collection efficiency will decrease. In addition, the pressure loss due to clogging increases significantly, and the life of the filter is shortened.

Also, the price of the filter is high.

Replacing filters in a clean room factory (for example, semiconductor manufacturing) requires shutting down the factory for a period of time. It took a while to come back again. This resulted in wasted production capacity. Furthermore, in order to improve cleanliness, the number of ventilations was increased, which reduced power costs.

Furthermore, the main components of the method (11) are a fan, a pre-leakage charging section, and an electrostatic filter, and the pre-charging section requires a high-voltage power source.

This increases the size of the equipment, raises safety issues, complicates maintenance, and, for example, causes particles to accumulate and scatter onto the electrode plates. To maintain a high degree of cleanliness, operation must be performed with a considerable safety factor in mind. ), resulting in high costs.

As mentioned above, the air cleaning methods (1) and (11) have problems in terms of cost. Furthermore, although these methods can be used in industrial cleanrooms, it has been difficult to use them in biological cleanrooms (including local high-cleanliness equipment such as clean benches and Tallinn tunnels). In other words, filters always have pinholes and some contaminated air leaks out, so the air cleaning methods (11) and (11) using only filters have limitations in their use in biological clean rooms (some types of (Microorganisms can multiply rapidly in a short period of time and are dangerous).

[Object of the Invention] Accordingly, an object of the present invention is to provide an air purification method suitable for eliminating the above-mentioned drawbacks of air purification methods using only filters, and particularly suitable for air purification in biological clean rooms.

[Structure of the Invention] Therefore, according to the present invention, in purifying contaminated air containing fine particles, microorganisms, etc., the contaminated air is irradiated with ultraviolet rays, and the fine particles containing dead microorganisms are collected by a filter. Further, according to the present invention, nitrogen-enriched air is used to purify contaminated air containing fine particles, microorganisms, and the like. Further, if necessary, the nitrogen-enriched air is irradiated with ultraviolet rays, and particulates containing dead microorganisms and the like are collected by a filter.

In this way, the present invention irradiates contaminated air with ultraviolet rays,
Alternatively, since the air is converted into nitrogen-enriched air and turned into an inert gas, or if necessary, the nitrogen-enriched air is irradiated with ultraviolet rays, there is a risk that some contaminated air may leak through pinholes in the filter. Even so, the risk of proliferation of certain microorganisms in a short period of time is avoided, and the method can be very suitably used for air purification in biological clean rooms.

When carrying out the present invention, it is preferable to use deep ultraviolet rays as the ultraviolet rays. Further, it is preferable that the incoming air is passed through a pre-filter in advance to remove particulates, and then the incoming air is given a swirling motion to perform ultraviolet irradiation. Furthermore, an electrostatic filter can be suitably used as a filter for collecting fine particles containing dead microorganisms. When enriching with nitrogen, the concentration of nitrogen should be 82% or more.

[Example] The following is an example of a case in which the present invention is implemented in a clean booth combination method in a biological clean room (one of the methods to achieve high cleanliness only in a certain part of the work area), and the example will be described below. explain. FIG. 1 shows the first embodiment of the present invention.
An example is shown in which the interior of a conventional mechanical filter is maintained at a medium level of cleanliness, and only the workplace is maintained at a high degree of cleanliness. The air in the clean room 1 is obtained by removing coarse particles contained in the outside air 2 using a pre-filter 3, and the air inside the clean room 1 is taken out from the air intake port 4, and the fan 5
After the air is conditioned (temperature and humidity controlled Il) by an air conditioner 6, fine particles are removed by a filter 7 and the air is supplied to maintain a cleanliness level (class) of 100,000.

On the other hand, the work area is a clean booth 1 consisting of a fan 8, an ultraviolet irradiation unit 9, an electrostatic filter 10, and a transparent curtain 11.
2, the cleanliness (class) 10o is maintained on the workbench 13. In the clean booth 12 , air with a cleanliness level (class) of 100,000 in the clean room 1 is sucked in by a fan 8 and irradiated with ultraviolet rays by an ultraviolet irradiation unit 9 . Here, particles are charged by ultraviolet irradiation, and microorganisms (such as viruses, bacteria, various fungi, yeast, and mold) are sterilized.

Any type of ultraviolet rays may be used as long as it has the ability to charge particles and sterilize microorganisms, but from the viewpoint of efficiency, far ultraviolet rays (1
900A' or less) is preferred. Furthermore, a rotating motion can be provided by a fan to increase the efficiency of ultraviolet irradiation.

Fine particles containing dead microorganisms are collected by an electrostatic filter 10. Any electrostatic filter can be used as long as it is a one-type electrostatic filter. Usually, a structure in which glass fiber is polarized by electric lines of force is used, but a structure in which the cap itself is an electrode, such as steel wool as a non-electrode, is used. is also valid.

Since some of the electrostatic filters become clogged after use for a certain period of time, the entire clean room can be operated safely by using a cartridge structure as necessary and replacing them by detecting pressure loss (not shown).

The fan 8, ultraviolet irradiation unit 9, and part of the electrostatic filter 10 are normally arranged in the order described above, but the size of the air purification type (small, medium, large) and the airflow type (horizontal type) , vertical type, circular type), etc.

Biological clean rooms can also be built in the same way according to the above method, but if you want to reduce costs (especially when high cleanliness is required such as class 1, 0 or class 100), the entire room can be constructed using the above method or Medium cleanliness (e.g. class 10000, class 1000
00), and only the workplace (for example, clean booth, clean bench, clean tunnel) is thoroughly cleaned using the method described above.

Examples of uses for water droplets include air purifiers for offices and playgrounds for small devices, and clean booths, clean benches, clean tunnels, sterile air blowers, air showers, and pass boxes for medium-sized devices. In the case of even larger equipment, clean rooms, especially biological clean rooms, can be mentioned.

FIG. 2 shows a second embodiment of the invention, in which inerting is performed with nitrogen-enriched air.

In Figure 2, the interior of clean room 1 is maintained at a medium level of cleanliness (class) using a mechanical filter, and the work area (
Only the inside of the clean bench 15 is kept in a highly clean and inert atmosphere by spraying water.

As in the case of the first embodiment, the air in the clean room 1 is obtained by removing coarse particles contained in the outside air 2 with the prefilter 3, and the air inside the clean room 1 is taken out from the air intake port 4, and the air is passed through the fan 5. After air WA (temperature and humidity control) is performed in the conditioner 6, fine particles are removed by the filter 7 and the air is supplied to maintain a cleanliness level (class) of 100,000.

The clean bench 15 measures the cleanliness inside the clean room 1 (
Class) 100,000 air is sucked into the nitrogen-enriched membrane chamber 14 by a suction blower 17.

The nitrogen-enriching membrane chamber 14 mainly consists of an air suction section and a nitrogen-enriching membrane cell, and separates oxygen from the air to obtain nitrogen-enriched air. Ventilated.

Nitrogen IIa here is 82% or more, preferably 85% or more, most preferably 90% or more, and the optimum concentration is determined by the type of work, field of application, use, economy, etc. In general, when working in aseptic conditions, such as in the pharmaceutical and food industries, a higher nitrogen concentration of 11 degrees is preferable, but when culturing bacteria and mold tissue, such as in the medical, agricultural, forestry, and livestock industries, the nitrogen concentration is comparatively low. It's good to be short on the mark.

Next, the nitrogen-enriched air is irradiated with ultraviolet rays in the ultraviolet irradiation section 9 to remove microorganisms (e.g. viruses, bacteria, various fungi,
Yeast, mold) are sterilized. A filter 10 then removes particulates, including dead microorganisms, and a constant flow of inert and sterile air covers the workbench 13.

Instruments, products, etc. are taken in and out of the workbench 13 in the clean bench 15 using a movable shutter 16 attached to the clean bench 15. nitrogen enrichment membrane chamber 14, ultraviolet irradiation section 9,
The arrangement order of the filter part 10 and the fan 18 is normally the above-mentioned order, but it may vary depending on the scale of the air-oil soap type type, the airflow method, etc. Further, it goes without saying that if the purpose is achieved with nitrogen-enriched air and charging and/or sterilization by ultraviolet irradiation is not necessary, the part related to ultraviolet irradiation can be omitted. Fields of application of this method include medical care, pharmaceuticals, food, agriculture, forestry and livestock, and applications include clean booths, clean tunnels, clean benches, safety cabinets, sterile rooms, pass boxes, and sterile air curtains.

[Actions and effects of the invention] The effects of the present invention are listed below.

(b) Microorganisms can be sterilized and sterilized clean air can be obtained.

(b) Biotechnology-related (e.g. medical, pharmaceutical,
It is effective in cases where the presence of microorganisms is important and the presence of fine particles is not so important, such as in food, agriculture, forestry and livestock industries.

(c) Conventional mechanical filters have leaks due to pinholes, and in the biotechnology field, there were concerns about leakage of microorganisms, rapid multiplication, and contamination due to leaked air. The collection does not have to be strict, and leaks can be tolerated.

(d) In view of the above, the filters in the workplace need only be relatively coarse, and the frequency of ventilation can be reduced, which means that they need to be replaced less frequently (they last longer and are easier to maintain and manage). Also, power costs will be lower.

(e) Since fine particles containing dead microorganisms are pre-charged, they can be efficiently removed by providing an electrostatic filter downstream.

(f) It is inert and can sterilize microorganisms, providing inert, sterile, clean air.

(g) Since there is less 02, there is no generation of harmful components such as 03 and NOx.

(H) The outlet 810 opposite to the nitrogen-enriched air outlet becomes oxygen-enriched air, and this air can be effectively used by supplying it to the combustion equipment shade. Moreover, this air can be effectively used for medical purposes (for example, as a substitute for 02 cylinders).

(S) The main components are the fan section, ultraviolet irradiation section, part of the filter, or suction blower and fan section, nitrogen enrichment section,
It is part of the ultraviolet irradiation part and part of the filter, so maintenance is safe and there are no safety issues. In addition, since inert air is obtained, microbial activity is calmed down, making it useful in biotechnology-related equipment.

As described above, this technology can greatly contribute to the research and development of biotechnology, which is expected to rapidly develop in the future.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an apparatus for implementing the method of the first embodiment of the present invention, and FIG. 2 is a system diagram of the apparatus for implementing the method of the second embodiment of the invention. 1...Clean room 2...Outside air 3...Pre-filter 4...Air intake port 5...Fan 6
...Air conditioner 7...Filter 8.°...
Fan 9...Ultraviolet irradiation section 10...Electrostatic filter 11...Transparency 12...Clean booth 13...Work table 14...Nitrogen enrichment membrane chamber 15...Clean Bench 16... Movable shutter 17... Suction blower 18... Fan

Claims (2)

[Claims] (1) An air purification method characterized by irradiating the contaminated air with ultraviolet rays and collecting the dead particles containing the microorganisms with a filter in purifying the contaminated air containing particles and microorganisms. (2) In purifying contaminated air containing fine particles and microorganisms, the contaminated air is converted into nitrogen-enriched air, the nitrogen-enriched air is irradiated with ultraviolet rays, and the fine particles containing dead microorganisms are collected using a filter. A distinctive air purification method.