JPH042852B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an air purification method for purifying indoor contaminated air containing fine particles containing microorganisms, and is particularly suitable for use in air purification in biological clean rooms. Concerning air purification methods.

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

Among these, the main components of the method () 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 coarse in an attempt to reduce the pressure drop, the dust collection efficiency will decrease. In addition, the pressure loss due to clogging increases significantly, and the life of the filter is shortened.
And the price of the filter is also high.

When replacing filters in a clean room factory (for example, semiconductor manufacturing), the factory must be stopped for the period. 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 increased power costs.

Furthermore, the main components of the method () were a fan, a precharging section, and an electrostatic filter, and the precharging section required a high-voltage power source. This increases the size of the equipment, raises safety issues, and complicates maintenance and management (for example, particles accumulate and scatter on the electrode plates, and maintaining a high level of cleanliness requires operation with a considerable safety factor in mind. , resulting in high costs).

As mentioned above, the air cleaning methods () and () had problems in terms of cost. Furthermore, although these methods can be used in industrial clean rooms, it has been difficult to use them in biological clean rooms (including local high-cleanliness devices such as clean benches and Clinton channels). In other words, filters always have pinholes and some contaminated air leaks out, so the air cleaning methods () and () 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).

To this end, Japanese Patent Publication No. 38-23438 discloses a technique in which ultraviolet rays are irradiated and fine particles are collected by a filter. However, with such known techniques, microorganisms in contaminated air leaking from, for example, pinholes in the filter may grow.

[Problems to be Solved] Accordingly, an object of the present invention is to provide an air cleaning method that prevents microorganisms from multiplying in a short period of time due to leakage of contaminated air.

[Means for Solving the Problems] According to the present invention, in an air purification method for purifying indoor contaminated air containing fine particles containing microorganisms, the contaminated air is nitrogen-enriched air, and the nitrogen-enriched air is irradiated with ultraviolet rays. , dead microorganisms and fine particles are collected by a filter.

[Explanation of effects] Therefore, even if a part of the contaminated air leaks, the nitrogen-enriched air inerts the air, avoids the danger of microorganisms multiplying in a short period of time, and improves biological clean rooms. Extremely effective as an air purifier.

[Preferred Embodiment] 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.

In FIG. 1, the interior of the clean room 1 is maintained at a medium level of cleanliness (class) using a conventional mechanical filter, and only the work area (inside the clean bench 15) is maintained at a high level of cleanliness. Clean room 1
The air from which coarse particles contained in the outside air 2 have been removed by a prefilter 3 and the air inside the clean room 1 are taken out from an air intake port 4, and air conditioned (temperature, humidity, etc.) by an air conditioner 6 via a fan 5. control), the filter 7 removes fine particles and supplies the water, maintaining a cleanliness level (class) of 100,000.

The clean bench 15 consists of a nitrogen-enriched membrane chamber 14, an ultraviolet irradiation section 9, and an electrostatic filter 10, and maintains a cleanliness (class) of 100 on the workbench 13. That is, in the clean bench 15, air with a cleanliness (class) of 100,000 in the clean room 1 is sucked into the nitrogen enriched membrane chamber 14 by the 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.

The nitrogen concentration here is more than 82%, preferably 85%
The most preferred concentration is 90% or more, and the optimum concentration is determined by the type of work, field of application, use, economic efficiency, etc. In general, when it is preferable to work in aseptic conditions, such as in the pharmaceutical and food industries, a higher nitrogen concentration is preferable;
When culturing mold tissue, the nitrogen concentration may be relatively low.

Next, the nitrogen-enriched air is irradiated with ultraviolet rays in the ultraviolet irradiation section 9 to sterilize microorganisms (such as viruses, bacteria, various fungi, yeast, and mold). Fine particles, including dead microorganisms, are then removed by a filter 10, and a constant flow of inert and sterile air is blanketed over the workbench 13.

Instruments to the workbench 13 in the clean bench 15,
Loading and unloading of products, etc. is performed using a movable shutter 16 attached to the clean bench 15. Nitrogen enrichment membrane chamber 1
4. The arrangement order of the ultraviolet ray irradiation section 9, filter section 10, and fan 18 is normally the above-mentioned order, but it may vary depending on the scale of the type of air cleaning system, the airflow system, etc. Application fields of this method include medical care, pharmaceuticals, food, agriculture, forestry and livestock, and applications include clean booths, clean tunnels,
These include clean benches, safety cabinets, sterile rooms, pass boxes, and sterile air curtains.

[Effects of the Invention] The effects of the present invention are enumerated as follows.

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

(b) 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 biotechnology-related fields (for example, medical, pharmaceutical, food, agricultural, livestock, and livestock-related fields).

(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 can be relatively coarse, and the number of ventilations 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 in the wake.

(F) It is inert and can sterilize microorganisms, providing inert, sterilized clean air.

(g) Since there is little O ₂ , there is no generation of harmful components such as O ₃ and NOx.

(H) The outlet opposite to the nitrogen-enriched air outlet becomes oxygen-enriched air, and this air can be effectively used by supplying it to a combustion device, etc. This air can also be effectively used for medical purposes (for example, as a substitute for O ₂ cylinders).

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

[Brief explanation of drawings]

FIG. 1 is a system diagram of an apparatus for carrying out a method according to an embodiment of the present invention. 1...Clean room, 2...Outside air, 3...Prefilter, 4...Air intake port, 5...Fan, 6...Air conditioner, 7...Filter, 9
... Ultraviolet irradiation section, 10 ... Electrostatic filter, 1
1...Transparent curtain, 13...Work table, 14...
Nitrogen enrichment membrane room, 15...Clean bench (work area), 16...Movable shutter, 17...Suction blower, 18...Fan.

Claims (1)

[Claims] 1. In an air purification method for purifying indoor contaminated air containing fine particles containing microorganisms, the contaminated air is nitrogen-enriched air, the nitrogen-enriched air is irradiated with ultraviolet rays, and the dead microorganisms and fine particles are collected by a filter. An air purification method characterized by: