WO2016060284A1

WO2016060284A1 - Chlorine dioxide gas fumigation apparatus

Info

Publication number: WO2016060284A1
Application number: PCT/KR2014/009604
Authority: WO
Inventors: 김종락; 박희석
Original assignee: (주)푸르고팜
Priority date: 2014-10-14
Filing date: 2014-10-14
Publication date: 2016-04-21

Abstract

A chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention comprises: a body having a first space into which source material solution for generating chlorine dioxide gas is injected, and a second space that is separated from the first space; a first electrode that contacts the source material solution in the first space; a second electrode that is exposed in the second space; a cleaning part for spraying cleaning material toward by-products attached to the surface of the second electrode during electrolysis of the source material solution as a voltage is applied to the first electrode and the second electrode.

Description

Chlorine Dioxide Gas Fumigation Equipment

The present invention relates to a chlorine dioxide gas fumigation apparatus.

In agricultural and livestock products, decaying microorganisms, physiological effects, or temperature conditions act in combination during storage and distribution to consumers. The loss rate ranges from 20% to 30% of the total agricultural product, which translates into trillions of dollars in economic losses.

To reduce losses during the storage and distribution of agricultural and livestock products, the cold chain method has been mainly used to date, and the modified atmosphere (CA) and modified atmosphere (MA) which reduce oxygen and increase carbon dioxide by changing the air composition of the sealed storage space ) Storage is also used. In addition, a method of controlling ethylene, which acts as an aging hormone in plants, is emerging. In the case of livestock products, there are techniques for maintaining freshness by applying various methods such as temperature control and vacuum packaging.

However, it is difficult to control the accelerated decay of the concentrate by the microorganisms without lowering the density of the microorganisms attached to the surface of the concentrate. In order to remove microorganisms, some crops are washed with a disinfectant solution to remove microorganisms, but most fruit crops and herbs, including strawberries, grapes and peaches, are inherently incapable of contact with aqueous solutions, and livestock products do not have an alternative. to be.

Even if the contact of the solution is allowed, the results of the experiment show that the sterilization effect on the microorganisms living in the cracked or injured crevices of the concentrated product is much higher than that of the solution sterilization.

Compared to solution wash sterilization, the application of gas fumigation can result in the sterilization effect due to the contact of gas and crops through very fine air holes after product packaging.

There are many materials used in such a method of gas fumigation. In the case of the sulfur fumigation method, the possibility of harm to humans is a problem, and MB (methyl bromide) fumigation is being banned as an ozone depleting substance, while chlorine dioxide is a food additive registered with the KFDA. It is an environmentally friendly organic handling material registered for cleaning and disinfection.

Chlorine dioxide has a wide range of effects as an oxidizing fungicide from fungi to bacteria and viruses, and microbial sterilization mechanisms are known to kill microorganisms by penetrating the protective membrane of microorganisms and interfering with the enzyme's action of cells by oxidative power.

This bactericidal power is effective in a wide pH range and is more than 2.5 times stronger than chlorine and does not produce carcinogens such as THM (trihalomethane), so it has been spotlighted as an environmentally friendly green fungicide in Europe or the United States. The United Nations World Health Organization (WHO) and the Food and Agriculture Organization (FAO) recommend chlorine dioxide as a disinfectant.

Research on various devices capable of generating such chlorine dioxide is underway.

Chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention is to remove by-products generated when generating chlorine dioxide gas by using electrolysis.

According to an aspect of the present invention, a body having a first space in which the raw material solution for the generation of chlorine dioxide gas is injected, and a second space partitioned from the first space; A first electrode in contact with the raw material solution in the first space; A second electrode exposed to the second space; Chlorine dioxide gas fumigation apparatus including a washing unit for spraying the cleaning material toward the by-product attached to the surface of the second electrode in the process of the electrolysis of the raw material solution as the voltage applied to the first electrode and the second electrode Is provided.

The raw material solution may include sodium chlorite, and the by-product may include sodium hydroxide.

The cleaning material may include H ₂ O or a material having an acidic group.

The substance having an acidic group may be citric acid solution or acetic acid solution.

The washing unit may include a nozzle unit provided in the second space to spray the washing material toward the second electrode, a washing material flow passage communicating with the nozzle unit to transfer the washing material to the nozzle unit, and the washing material. The cleaning material may include a pump for cleaning material installed in the cleaning material flow path so that the cleaning material is transferred.

The chlorine dioxide gas fumigation apparatus further includes a discharge unit, the discharge unit is a discharge pump which is provided in the discharge flow path for transporting the cleaning material in the second space, and the cleaning material in the second space; It may include.

As voltage is applied to the first electrode and the second electrode, the chlorine dioxide gas may be generated through electrolysis of the raw material solution containing no sodium chloride.

The object exposed to the chlorine dioxide gas is exposed to the chlorine dioxide gas of the second concentration band lower than the first concentration band after being exposed to the chlorine dioxide gas of the first concentration band for a first time in the target space where the object is placed. Exposed for a second time longer than 1 hour, the cleaning strength for the by-product when the object is exposed to chlorine dioxide gas in the first concentration band is such that the object is exposed to chlorine dioxide gas in the second concentration band. When compared to the wash strength for the by-products of the time.

The lower limit concentration of the first concentration band is 5 ppm or more, the upper limit concentration is 300 ppm or less, the upper limit concentration of the second concentration band is 0.3 ppm or less, and the lower limit concentration of the second concentration band may be 0.03 ppm or more.

As the magnitude of the current supplied to the first electrode and the second electrode increases, the washing strength of the by-product of the washing part may increase.

The chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention can increase the efficiency of the fumigation apparatus by washing the by-products of the electrode surface generated during the electrolysis process.

1 shows a chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention.

Figure 2 shows an embodiment of the chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention.

FIG. 3 shows the object density after a predetermined time after the object A is exposed to chlorine dioxide gas satisfying the first concentration band.

FIG. 4 shows the uniform density of objects after a predetermined time after the exposure of the object A, the object B, and the object C to the chlorine dioxide gas satisfying the second concentration band lower than the first concentration band.

FIG. 5 shows the uniform density of the object A when the object A is exposed to the chlorine dioxide gas satisfying the second concentration band for a predetermined time after exposure to the chlorine dioxide gas satisfying the first concentration band.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of this embodiment, the same name and the same reference numerals are used for the same configuration and additional description thereof will be omitted.

1 shows a chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention. As shown in FIG. 1, the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention includes a body 110, a first electrode 120, a second electrode 130, and a washing unit 140.

The body 110 has a first space S1 into which a raw material solution for generating chlorine dioxide gas is injected, and a second space S2 partitioned from the first space S1. The raw material solution may be stored in the first tank 150 and may be injected into the first space S1 of the body 110 through the raw material solution pump 161 and the raw material solution valve 162. The raw material solution pump 161 and the raw material solution valve 162 may be provided in the raw material solution passage 163 through which the raw material solution is transferred.

The first electrode 120 is in contact with the raw material solution of the first space S1, and the second electrode 130 is exposed to the second space S2.

As the voltage is applied to the first electrode 120 and the second electrode 130, the washing unit 140 may cleanse the cleaning material toward the by-product attached to the surface of the second electrode 130 in the process of electrolyzing the raw material solution. Spray.

One side of the body 110 may be provided with an electrolyte injection port 111 into which a raw material solution containing sodium chlorite (NaClO ₂ ) is injected and a first outlet 112 through which chlorine dioxide (ClO ₂ ) gas is discharged. In addition, the second outlet 113 may be formed on the other side of the body 110 and the other side. By-products generated in the process of generating chlorine dioxide gas may be discharged through the outlets. By-products are described in detail later.

The conductive film 145 may be provided inside the body 110. The first space S1 and the second space S2 of the body 110 may be partitioned by the conductive film 145. The conductive film 145 may be provided in hydrocarbon and fluorocarbon type as a proton conductive material, wherein the fluorocarbon type resin may have excellent oxidation resistance against halogen, strong acid and base.

The first electrode 120 corresponds to an anode layer, is connectable to a power source (not shown), and may be in contact with one side of the conductive layer 145. The second electrode 130 may correspond to a cathode layer and may be connected to a power source and may be in contact with the other side of the conductive film 145 opposite to one side. The first electrode 120 causes an oxidation reaction with sodium chlorite, which is an electrolyte, and the second electrode 130 causes a reduction reaction. Since the connection between the power source and the first electrode 120 and the second electrode 130 is a general technique to those skilled in the art, a detailed description thereof will be omitted.

The first electrode 120 and the second electrode 130 may further include an electrochemical catalyst to maximize the efficiency of the redox reaction. The electrochemical catalyst may be platinum, palladium, rhodium, iridium, ruthenium, osmium, carbon, gold, tantalum, tin, indium, nickel, tungsten, manganese, or mixtures comprising at least one of them, oxides, alloys, or combinations thereof Can be.

Sodium chlorite (NaClO 2) injected through the electrolyte injection port 111 may be composed of sodium chlorite (NaClO 2) salt and water (H 2 O). Sodium chlorite (NaClO 2) salt is converted into chlorine dioxide (ClO 2) gas, sodium ions (Na +) and electrons (e −) by an oxidation reaction of the first electrode 120, and water is transferred to the first electrode 120. Oxidation reaction converts oxygen (O2) gas, hydrogen ions (H +) and electrons (e-).

Chlorine dioxide (ClO2) gas and oxygen (O2) gas formed by the oxidation reaction of the first electrode 120 is discharged to the outside through the first outlet 112, sodium ions (Na +) and hydrogen ions (H +) It moves to the second electrode 130 through the conductive film 145 by electrical attraction.

At this time, water (H 2 O) together with sodium ions (Na +) and hydrogen ions (H +) may move together. The hydrogen ions (H +) moved to the second electrode 130 become hydrogen by a reduction reaction by the second electrode 130, and the sodium ions (Na +) are combined with OH ⁻ of water (H 2 O) to form sodium hydroxide ( NaOH). That is, by-products are generated during the electrolysis process, and the by-products may include hydrogen and sodium hydroxide.

Sodium hydroxide is a by-product generated in the process of generating chlorine dioxide gas through electrolysis, and when sodium hydroxide is attached to the second electrode 130, it may act as a resistance that interrupts the flow of current. When the amount of sodium hydroxide attached to the second electrode 130 increases, the amount of current required to generate chlorine dioxide gas increases, so that the efficiency of electrolysis may decrease.

The chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention includes a washing unit 140 capable of removing sodium hydroxide attached to the second electrode 130. The operation and structure of the cleaning unit 140 will be described in detail later with reference to the drawings.

On the other hand, the electrochemical catalyst of the first electrode 120 and the second electrode 130 promotes the oxidation reaction of the first electrode 120 and the reduction reaction of the second electrode 130, as described above. The conductive layer 145 may contact the first electrode 120 and the second electrode 130 without a gap between the 145 and the first electrode 120 and a gap between the conductive layer 145 and the second electrode 130. have.

Such a gap serves as a resistance that interrupts the flow of current. When both sides of the conductive layer 145 are in contact with the first electrode 120 and the second electrode 130 as in the embodiment of the present invention, the current flows. This improvement can increase the generation efficiency of chlorine dioxide gas through electrolysis.

Unlike the chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention, when the first electrode 120 and the second electrode 130 are spaced apart from the conductive film 145, sodium chloride (NaCl) to prevent the degradation of the electrolysis efficiency. This may be added together with sodium chlorite. In this case, chlorine is generated due to the electrolysis of sodium chloride, which may harm the human body.

On the other hand, in the embodiment of the present invention, as voltage is applied to the first electrode 120 and the second electrode 130, chlorine dioxide gas may be generated through electrolysis of a raw material solution containing no sodium chloride. That is, since there is no gap between the conductive film 145 and the first electrode 120 and between the conductive film 145 and the second electrode 130, the input of sodium chloride is not necessary, so damage due to chlorine can be prevented. In addition, since there is no gap between the conductive layer 145 and the first and second electrodes 130, resistance due to the gap does not occur, and thus the generation efficiency of chlorine dioxide gas may be improved.

Meanwhile, the cleaning material sprayed by the cleaning unit 140 may include a material having H ₂ O or an acidic group. Sodium hydroxide is soluble in water, so water can be used as a cleaning material. In addition, since the acidic group combines smoothly with OH- of sodium hydroxide, a substance having an acidic group may also be used as a washing material.

For example, the substance with acidic groups may be citric acid solution or acetic acid solution. Citric acid solution or acetic acid solution is diluted with citric acid or acetic acid in water, inexpensive, harmless to the human body and easy to obtain.

The cleaning unit 140 may include a nozzle unit 141, a cleaning material flow path 142, and a cleaning material pump 143. The nozzle unit 141 may be provided in the second space S2 of the body 110 to spray the cleaning material toward the second electrode 130. As shown in FIG. 2, a nozzle passage 144 communicating with the washing material passage 142 may be formed in the nozzle unit 141.

The cleaning material flow path 142 communicates with the nozzle unit 141 to transfer the cleaning material to the nozzle unit 141. The cleaning material pump 143 may be installed in the cleaning material flow path 142 so that the cleaning material is transferred to the cleaning material flow path 142. In this case, the cleaning material may be stored in the second tank 155 of FIG. 1, and a cleaning material valve 146 may be provided in the cleaning material flow path 142 to control the flow of the cleaning material.

On the other hand, the chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention may further include a discharge unit (170). The discharge unit 170 is a discharge pump 172 provided in the discharge passage 171 communicated with the second space (S2), and the discharge passage 171 to transfer the cleaning material of the second space (S2). It may include. At this time, the discharge valve 173 for controlling the flow of the cleaning material may be provided in the discharge passage (171). Since the sodium hydroxide attached to the second electrode 130 is washed by the cleaning material, the discharged cleaning material may include sodium hydroxide as a by-product.

The raw material solution pump 161, the cleaning material pump 143, the discharge pump 172, the raw material solution valve 162, the cleaning material valve 146 and the discharge valve 173 are described above. The controller 180 may be controlled, and the controller 180 may output a valve control signal and a pump control signal.

According to the input of the valve control signal, the raw material solution valve 162, the cleaning material valve 146, and the discharge valve 173 are the raw material solution, the cleaning material flowing into the second space S2, and the second space S2. It is possible to control the amount of the washing material discharged from the) and to open and close the raw material solution flow path 163, the cleaning material flow path 142 and the discharge flow path (171). In addition, according to the input of the pump control signal, the operation of the raw material solution pump 161, the pump for cleaning material 143 and the discharge pump 172, the operation stop, and the pumping amount of the raw material solution and the washing material can be controlled. have.

Next, with reference to the drawings will be described the relationship between the concentration band (band) and washing of the chlorine dioxide gas fumigation apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention may supply chlorine dioxide gas to a target space through a gas supply valve 191 and a gas supply pump 192. The gas supply valve 191 and the gas supply pump 192 may also be controlled by the controller 180 described above.

According to the control of the controller 180, the gas supply valve 191 may control the amount of chlorine dioxide gas flowing and open and close the gas supply flow passage 193. In addition, according to the input of the pump control signal, the operation of the gas supply pump 192, the operation stop, and the pumping amount of chlorine dioxide gas can be controlled.

The target space may be a space to which chlorine dioxide gas is supplied. For example, the target space may be a warehouse, a container box, a pig farm, or a poultry farm in which the agricultural products are stored or grown, but is not limited thereto.

3 to 5 show the effect of using different concentration bands for the same object. The object placed in the object space may be exposed to the chlorine dioxide gas supplied by the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention.

FIG. 3 shows the average density of object A when object A is 10 days after being exposed to chlorine dioxide gas satisfying the first concentration band for 30 minutes. The upper limit offset of the first concentration band may be 10% of the reference concentration k, and the lower limit offset may be −10% of the reference concentration k. Accordingly, the concentration of chlorine dioxide gas in the target space may vary between 1.1k and 0.9k.

In this case, the reference concentration, the upper limit offset and the lower limit offset may vary depending on the type of the object or the internal volume of the object space.

As shown in FIG. 3, since the object is exposed to a high concentration of chlorine dioxide gas, the bacterial density decreases rapidly until two days or three days, after which the bacterial density gradually increases.

FIG. 4 shows the uniform density in object A, object B and object C when exposed to chlorine dioxide gas for a second concentration band lower than the first concentration band for 10 days.

In this case, the reference concentration, the upper limit concentration, and the lower limit concentration of the second concentration band may be 0.05 ppm, 0.1 ppm, and 0.03 ppm, respectively. As shown in FIG. 4, since the target A target B and the target C are exposed to the low concentration of chlorine dioxide gas, the microbial density does not decrease until 10 days and the change in the microbial density is small.

FIG. 5 shows the average density of the object A when the object A is exposed to the chlorine dioxide gas satisfying the low concentration second concentration band for 10 days after being exposed to the chlorine dioxide gas satisfying the high concentration first concentration band for 30 minutes. .

Since the first concentration band and the second concentration band have been described above with reference to FIGS. 3 and 4, description thereof will be omitted.

As shown in FIG. 5, since the object A is exposed to the high concentration of chlorine dioxide gas in the first concentration band, the bacterial density decreases rapidly until two days or three days. Since the object A is exposed to the chlorine dioxide gas of the second concentration band of low concentration, the reduced density can be maintained continuously.

As described above, when the object exposed to chlorine dioxide gas is exposed to the high concentration of chlorine dioxide gas of the first concentration band in the target space and then to the low concentration of chlorine dioxide gas of the second concentration band, the sterilization efficiency is shown in FIGS. 3 and 4. It can be seen that higher than the sterilization efficiency.

In the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention, the object exposed to the chlorine dioxide gas is lower than the first concentration band after being exposed to the chlorine dioxide gas of the first concentration band for a first time in the target space in which the object is placed. The chlorine dioxide gas may be supplied to the target space to be exposed to the chlorine dioxide gas in the two concentration bands for a second time longer than the first time.

That is, when the internal volume of the target space is large, the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention supplies a high concentration of chlorine dioxide gas corresponding to the first concentration band to the target space in a short time, the chlorine dioxide gas in the target space. The concentration can be reached to the target concentration. In addition, since a high concentration of chlorine dioxide gas is supplied to the target space for a short time, the possibility of high concentration of chlorine dioxide gas affecting the human body can be lowered.

Subsequently, the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention can maintain a uniform density of the object by supplying a low concentration of chlorine dioxide gas corresponding to the second concentration band to the target space for a long time.

In this way, the chlorine dioxide gas satisfying the first concentration band is supplied during the first time period and the chlorine dioxide gas satisfying the second concentration band is supplied during the second time period through the gas supply valve 191 of the controller 180. It can be made through the control for the gas supply pump 192.

At this time, the washing strength for the by-product when the object is exposed to the chlorine dioxide gas in the first concentration band may be greater than the washing strength for the by-product when the object is exposed to the chlorine dioxide gas in the second concentration band.

That is, as the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention supplies a high concentration of chlorine dioxide gas corresponding to the first concentration band, the amount of chlorine dioxide gas generated through electrolysis may increase. Accordingly, by-products such as sodium hydroxide generated during the electrolysis process for generating chlorine dioxide gas may also increase, and the washing strength of the washing unit 140 to remove the by-products may also increase.

In the embodiment of the present invention, the washing strength may include at least one of the spraying speed of the washing material or the number of spraying per unit time. In this case, the injection speed may be defined as the amount of cleaning material sprayed per unit time.

As described above, supplying the chlorine dioxide gas so that the chlorine dioxide gas fumigation apparatus according to the embodiment of the present invention satisfies the first concentration band and the second concentration band, in order for the target space to store or grow the agricultural products. The volume of the target space should be large because it is difficult to maintain the concentration of chlorine dioxide uniformly throughout the target space as the volume of the target space increases.

That is, the chlorine dioxide fumigation apparatus according to the embodiment of the present invention controls the concentration of chlorine dioxide gas in the target space by supplying chlorine dioxide gas so that the chlorine dioxide concentration of the target space is in the set first and second concentration bands. It can be done easily.

Although not shown in FIG. 1, a concentration sensor may be installed in the target space. The controller 180 may receive the sensing signal of the concentration sensor and output a valve control signal and a pump control signal such that the concentration of chlorine dioxide gas in the target space satisfies the first concentration band and the second concentration band.

Meanwhile, the lower limit concentration of the first concentration band may be 5 ppm or more and the upper limit concentration may be 300 ppm or less. When more than 5 ppm of chlorine dioxide gas is injected in the target space, sterilization of the target such as concentrated agricultural products is sufficiently performed in a short time, thereby preventing or minimizing damage to the human body. In addition, when chlorine dioxide gas having a concentration of 300 ppm or less is supplied to the target space, it is possible to achieve sufficient sterilization within a short time even for a concentrated product having a large shell thickness such as orange or sweet pumpkin.

In addition, the upper limit concentration of the second concentration band may be 0.3 ppm or less and the lower limit concentration of the second concentration band may be 0.03 ppm or more. Human exposure to 0.3 ppm of chlorine dioxide for 15 minutes is harmless to humans. In addition, sterilization of the concentrated product may be performed when the concentration of chlorine dioxide is 0.03 ppm or more.

As the magnitude of the current supplied to the first electrode 120 and the second electrode 130 increases, the washing strength of the by-product of the washing unit 140 may increase. As the amount of chlorine dioxide gas generated per unit time increases, that is, as the amount of current supplied to the first electrode 120 and the second electrode 130 increases, the amount of by-products may also increase. Accordingly, the washing unit 140 may increase the washing strength for the by-products such as sodium hydroxide. Since the washing strength has been described above, a description thereof will be omitted.

In the above description, time information such as a first time and a second time may be input from the timer 200 to the controller 180.

As described above, the embodiments of the present invention have been described, and the fact that the present invention can be embodied in other specific forms without departing from the spirit or scope of the present invention can be embodied by those skilled in the art. It is self-evident to. Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive, and thus, the present invention is not limited to the above description and may be modified within the scope of the appended claims and their equivalents.

Claims

A body having a first space into which a raw material solution for generating chlorine dioxide gas is injected and a second space partitioned from the first space;

A first electrode in contact with the raw material solution in the first space;

A second electrode exposed to the second space;

Chlorine dioxide gas fumigation apparatus including a washing unit for spraying the cleaning material toward the by-product attached to the surface of the second electrode in the process of the electrolysis of the raw material solution as the voltage applied to the first electrode and the second electrode .
The method of claim 1,

The raw material solution comprises sodium chlorite, and the by-product chlorine dioxide gas fumigation apparatus, characterized in that containing sodium hydroxide.
The method of claim 1,

The chlorine dioxide gas fumigation apparatus, characterized in that the cleaning material comprises a substance having H 2 O or acidic groups.
The method according to any one of claims 1 to 3,

The material having an acidic group is chlorine dioxide gas fumigation apparatus, characterized in that the citric acid solution or acetic acid solution.
The method according to any one of claims 1 to 3,

The washing unit

A nozzle unit provided in the second space to spray the cleaning material toward the second electrode, a cleaning material flow path communicating with the nozzle part to transfer the cleaning material to the nozzle part, and the cleaning material flow path; Chlorine dioxide gas fumigation apparatus comprising a pump for the cleaning material installed in the flow path for the cleaning material so that the cleaning material is transferred.
The method according to any one of claims 1 to 3,

The chlorine dioxide gas fumigation apparatus further comprises a discharge,

The discharge unit chlorine dioxide gas fumigation apparatus, characterized in that it comprises a discharge passage provided in the discharge passage and the discharge passage communicating with the second space, the cleaning material of the second space.
The method according to any one of claims 1 to 3,

Chlorine dioxide gas fumigation apparatus, characterized in that the chlorine dioxide gas is generated through the electrolysis of the raw material solution containing no sodium chloride as a voltage is applied to the first electrode and the second electrode.
The method according to any one of claims 1 to 3,

The object exposed to the chlorine dioxide gas is exposed to the chlorine dioxide gas of the second concentration band lower than the first concentration band after being exposed to the chlorine dioxide gas of the first concentration band for a first time in the target space where the object is placed. Exposed for a second time period longer than 1 hour,

The wash strength for the byproduct when the object is exposed to chlorine dioxide gas in the first concentration band is greater than the wash strength for the byproduct when the object is exposed to chlorine dioxide gas in the second concentration band. Chlorine dioxide gas fumigation apparatus, characterized in that.
The method of claim 8,

The lower limit concentration of the first concentration band is 5 ppm or more and the upper limit concentration is 300 ppm or less,

The upper limit concentration of the second concentration band is 0.3 ppm or less and the lower limit concentration of the second concentration band is chlorine dioxide gas fumigation apparatus, characterized in that.
The method according to any one of claims 1 to 3,

Chlorine dioxide gas fumigation apparatus, characterized in that the washing strength of the by-products of the washing unit increases as the magnitude of the current supplied to the first electrode and the second electrode increases.