JPS60155503A - Decomposition of ozone - Google Patents

Abstract

PURPOSE:To decompose O3 into O2 simply and rapidly, by irradiating an O2- containing gas with microwave. CONSTITUTION:Air extracted from the operation space 4 by the blowe B is fed to the blending zone 2, blended with O3 evolved in the ozone generating zone 1 and sterilized. It is introduced into the microwave irradiating zone 3, irradiated with microwave having a frequency of 800MHz-30GHz for several seconds - several minutes, O3 is decomposed into O2, and the air is circulated through the operation space 4. Consequently, floating microorganism can be destroyed in shorter time of <=1/100 the time required by conventional thermal decomposition method or active carbon adsorption method.

Description

[Detailed description of the invention] Technical field to which the invention belongs The present invention relates to a method for efficiently decomposing ozone.

Conventional technology and its problems Ozone has a strong oxidizing effect and decomposes into harmless 6.
It is widely used for decolorizing 6 lights, Toshichifu, and Shino. Utilizing the sterilizing effect of ozone, microorganisms in the air can be sterilized and sterile air can be obtained. Such sterile air can be used in bioclean rooms, hospital waiting rooms, food factories, etc. to create a desired sterile atmosphere.

However, despite the sterility obtained by ozone treatment, ozone remains. Ozone is harmful to the human body even at low concentrations, and the ozone concentration in normal workplaces must be kept below 0.1 ppm.

Therefore, it is necessary to decompose residual ozone in the sterile air and supply sterile air that does not contain ozone to the target space.

Conventionally, natural decomposition methods, thermal decomposition methods, adsorption decomposition methods, ultraviolet decomposition methods, and the like are known as ozone decomposition methods.

The natural decomposition method is a method in which ozone is left to stand for a certain period of time to decompose. Ozone itself is chemically unstable, and if left untreated, it decomposes into oxygen. However, since the half-life of ozone at room temperature is quite long, 16 hours, its industrial applicability is poor. The pyrolysis method is a method of heating ozone to turn it into oxygen.

In this method, it is necessary to heat the ozone-containing air to at least 2,700 ℃, which not only increases the operating cost required for heating, but also complicates the process because the air after thermal decomposition must be cooled to room temperature. The adsorption decomposition method is a method in which ozone is adsorbed onto activated carbon, and the adsorbed ozone reacts with the activated carbon to form carbon dioxide and oxygen. In this method, there is a risk of explosion due to rapid reaction between ozone and activated carbon. Further, since the ultraviolet decomposition method has insufficient decomposition power, the desired decomposition effect cannot be obtained even if this method is used alone.

As described above, each of the conventional ozone decomposition methods has its own drawbacks, so methods of sterilizing the air with ozone have rarely been implemented, and methods of removing germs using filters have traditionally been used.

OBJECTS OF THE INVENTION The present invention overcomes the drawbacks of the prior art and aims to provide a method for decomposing ozone into oxygen much more easily and quickly than ever before.

That is, the present invention is a method of decomposing ozone by irradiating a gas containing ozone with microwaves.

Hereinafter, the present invention will be described in detail using the accompanying drawings.

FIG. 1 is a schematic system diagram showing a preferred embodiment of the present invention,
Ozone generation zone 1, mixing zone 2, microwave irradiation zone 6
, and a work space 4. In this method, air in the work space 4 is drawn out by a blower B and supplied to the mixing zone 2, where ozone generated from the ozone generation zone 1 and air are mixed. The ozone-mixed air is sent to the microwave irradiation zone where the ozone X is decomposed into oxygen, and the resulting sterile air is circulated to the work space 4 to create a sterile atmosphere in the work space 4.

The work space 4 may be any space that requires a sterile atmosphere, such as a bioclean room such as an operating room, a waiting room of a hospital, a building of a food manufacturing factory, or a pharmaceutical factory. In the method shown in FIG. 1, it is possible to create a sterile atmosphere in the work space 4 without containing ozone, so it is possible to create a sterile atmosphere in a space where people are present, such as an operating room or a hospital waiting room. It can be done.

The air that is also drawn off from the working space 4 is sent to the mixing zone 2 where it is mixed with ozone. The ozone generation zone 1 can be a conventional ozone generator, for example a silent discharge ozone generator or an ozone cylinder. Mixing band 2
The ozone concentration within may range from several tens of ppm to several thousand ppm, but is not particularly limited. Although the air may be sterilized by allowing the ozone mixed air to remain in the mixing zone 2 for a certain period of time,
As will be described later, in the microwave irradiation zone 6, the synergistic effect of ozone and microwaves produces a remarkable sterilization effect, so a method is adopted in which the residence time in the mixing zone 2 is made very short and, for example, ozone is injected into the piping. be able to.

The ozone mixed air flowing out from the mixing zone 2 is introduced into the microwave irradiation zone B, where the ozone mixed air is irradiated with microwaves. The microwave irradiation zone 6 mainly consists of a microwave generation source and a microwave irradiation space, and the ozone-mixed air receives microwave irradiation in this irradiation space.

The microwave frequency is particularly preferably in the range of 800 MHz to 30 GHz. The residence time of the ozone mixture air in the microwave irradiation zone 6 is not particularly limited, but can be from several seconds to several minutes.

Surprisingly, the inventors have discovered that when ozone is irradiated with microwaves, the ozone decomposes into oxygen and almost completely kills germs in the irradiated air. When performing sterilization, it is necessary to mix and hold air and ozone for several hours in order to perform sufficient sterilization, and it is also necessary to decompose and remove residual ozone in the obtained sterile air.The present invention It was discovered that according to this method, the seemingly contradictory effects of ozone decomposition and sterilization occur simultaneously and in a very short time.Ozone alone or microwave irradiation alone can hardly be expected to have a sterilizing effect. (・ is a short period of time, e.g. 2
Even with a residence time of 1 minute, complete air sterilization can be achieved by using ozone and microwaves simultaneously. This effect is thought to be due to the dramatic increase in the decomposition of ozone by microwaves.

FIG. 2 is a schematic system diagram showing another embodiment of the present invention. This method can effectively sterilize and disinfect germs adhering to the wall surface of the work space 4, and germs adhering to the surface of the operating table 5 or other articles installed in the work space 4. Ozone is introduced into the work space 4 from the ozone generation zone 1 and left for several hours to complete surface sterilization, and then the ozone-containing air in the work space is extracted by the nozzle B and sent to the microwave irradiation zone B, where the ozone is Work space 4 after decomposing into oxygen
circulates.

Conventionally, this type of surface sterilization mainly uses formalin, but the formalin sterilization method has problems such as formalin remaining on the surface of the article. In the method of the present invention, ozone is completely decomposed into oxygen and no ozone remains.

The chemical reaction in the method of the present invention can be considered as follows. The self-decomposition reaction of ozone is shown by the following formula: 03→0□10(0)...(1)03+(0)→
20°... (2) Active oxygen (◯) obtained by formula (1) has an extremely short lifespan, but is very active and quickly reacts with other ozone 03 to become oxygen. That is, when 03 self-decomposes to 0°, the reaction of equation (1) is considered to be the rate-determining step. It is thought that when ozone is irradiated with microwaves, the movement of ozone molecules becomes active and the reaction of equation (1) rapidly progresses to the right.

In addition, active oxygen (0) exhibits a strong oxidizing effect and easily combines with carbon and hydrogen in organic matter, converting organic matter into carbon monoxide,
Oxidatively decomposes to carbon dioxide and water vapor. If we replace the organic matter with bacteria in the air, it is thought that the bacteria in the air will react with some of the active oxygen generated by the decomposition of ozone, be oxidized and decomposed, and die. It is thought that in the method of the present invention, active oxygen rapidly increases due to microwave irradiation, and the sterilization rate is dramatically accelerated.

Although the case where the fluid to be sterilized is air has been described, the present invention can be applied not only to air but also to other gases such as nitrogen.

Example 1 Ozone concentration 5000 P by silent discharge ozone generator
pm, ozonized air was introduced into the microwave irradiation device at a flow rate of 250 ml/min. The microwave irradiation device used has an irradiation space of 21, a rated output of 500W, and a capacity of 2450M.
Generate H2 microwave.

The residence time of the ozonated air was 8 minutes. As a result of measuring the ozone concentration in the air flowing out from the microwave irradiation device, it was 4800 pprrL when the microwave was not irradiated.
On the other hand, when microwave irradiation is performed, it is 0.1 pp
It was found that it was less than m. Note that the ozone concentration was measured by the neutral potassium iodide method.

Example 2 The bactericidal effect of the present invention was studied. Yeast count 1.
7 x 107 pieces/punishment yeast culture (S, formo-se
rLsis) was sprayed into the spray chamber at a flow rate of 18 ml/rrbil to form yeast-containing air. This yeast-containing air is sucked at a flow rate of 31v=n, and ozone is added to this air to bring the ozone concentration in the sucked air to 600 ppm.
And so. The obtained ozone-containing air was introduced into the same microwave irradiation device as in Example 1. The residence time of air in the microwave irradiation device is 2 minutes.

The ozone concentration and the number of microorganisms in the air at the inlet and outlet of the microwave irradiation device were measured. Ozone concentration was measured using the neutral potassium iodide method. Regarding the number of microorganisms, air 501 to be measured was blown onto the agar medium using a pinhole sampler, the resulting medium was cultured in 3IC for 48 hours, the number of colonies that appeared on the surface of the medium was counted, and this was taken as the number of microorganisms. .

The average ozone concentration on the inlet side is 300 ppm, and the ozone concentration on the outlet side is 28 ppm without microwave irradiation.
0 ppm, and 0.0 ppm with microwave irradiation. It was less than lppm. The number of microorganisms is shown in Table 1.

As is clear from this example in Table 1, when ozone-containing air is irradiated with microwaves, ozone is completely decomposed and microorganisms in the air are almost completely killed.

According to the present invention, ozone can be almost completely decomposed into oxygen in a very short time by microwave irradiation.

In particular, compared to conventional pyrolysis methods or activated carbon adsorption decomposition methods, there is no need for a post-treatment cooling step and there is no risk of explosion.Furthermore, if the fluid to be treated contains airborne microorganisms, ozone In addition to disassembly, sterilization can be carried out in a shorter time than conventional methods, at less than 100%.The method of the present invention is also easy to operate, and the device can be made compact.For this reason, it can be installed in small spaces such as hospital waiting rooms. to create the desired sterile atmosphere.

[Brief explanation of the drawing]

1 and 2 are schematic system diagrams illustrating aspects of the present invention. 1...Ozone generation band, 2...Mixing band, 6...
Microwave irradiation band, 4... work space. Patent applicant: Shinryo Corporation (4 others)

Claims (1)

[Claims] 1) A method of decomposing ozone by irradiating a gas containing ozone with microwaves. 2) The method according to claim 1, wherein the gas is air. 3) The method according to claim 1, wherein the gas is characterized by microorganisms. 4) Microwave frequency is 800MH2 to 30GH
2. The method according to claim 1, wherein the method is: