JP2024021403A - Deodorizing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorizing method that can easily deodorize ammonia odor and acid odor.

SOLUTION: A method for deodorizing at least one of ammonia odor and acid odor on the interior surface of a deodorization target room 11 in a building utilizes a deodorant device 20. The deodorant device 20 has a two-fluid nozzle with a spray part 22, from which a chemical solution primarily composed of at least one of sodium hypochlorite solution, hypochlorous water, betaine solution and citric acid solution is sprayed until the interior relative humidity of the deodorization target room 11 reaches 80% or higher. The relative humidity is maintained at 80% or higher for a fixed duration (for example, 30 minutes).

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to a deodorizing method for eliminating ammonia odor, acid odor, etc. contained in excretion odor.

BACKGROUND ART Conventionally, excretory odors such as urine and fecal odors have been a problem in living rooms and hospital rooms such as recuperation wards where medical care and nursing care are provided. For example, there is the odor of excrement that is emitted from portable toilets installed in rooms such as living rooms and hospital rooms, and when changing diapers. Furthermore, when diapers are changed repeatedly, the odor generated from diaper excrement remains and stains indoor wallpaper, curtains, etc. Wallpaper and curtains stained with these odors become sources of odors in hospital rooms and living rooms.

Conventionally, odors that are ingrained in indoor wallpaper, curtains, etc. cannot be sufficiently eliminated simply by using passive measures such as ventilation and activated carbon adsorption. Therefore, active countermeasures were taken. As an active countermeasure against this problem, for example, spraying of highly concentrated ozone gas is carried out (see, for example, Patent Document 1). In this document, ozone gas is supplied to the mist outlet of the two-fluid nozzle to dissolve the mist generated by the two-fluid nozzle. Furthermore, the above-mentioned fog (ozone fog) is ejected using air containing residual ozone that is not dissolved in the fog, and is sprayed onto surfaces and spaces to be sterilized and deodorized.

Japanese Patent Application Publication No. 2004-173904

However, high concentrations of ozone are harmful to the human body. Therefore, when spraying high-concentration ozone into a room to deodorize the room, a seal is required to prevent leakage of high-concentration ozone. Furthermore, it is necessary to control the ozone gas concentration (lower it to a standard value of 0.1 ppm or less before entering the room). Therefore, it has been difficult to implement it frequently or easily.

A deodorizing method that solves the above problem is a deodorizing method that eliminates at least one of ammonia odor and acid odor attached to indoor surfaces, and uses a two-fluid nozzle to remove sodium hypochlorite solution, hypochlorite solution, Spraying a chemical solution containing at least one of chloric acid water, a betaine compound solution, and a citric acid solution as a main component until the relative humidity in the room reaches 80% or more, and maintaining the relative humidity of 80% or more after spraying, maintain.

According to the present invention, ammonia odor and acid odor can be easily eliminated.

It is a conceptual diagram explaining the composition of the room to be deodorized in an embodiment. It is an explanatory view explaining the composition of the deodorization device which performs deodorization in an embodiment. It is a flow chart explaining the processing procedure of deodorization processing in an embodiment. FIG. 2 is an explanatory diagram of a laboratory in which experiments were conducted on the deodorizing method in the embodiment. It is a table showing a chemical reaction formula between a sprayed chemical and ammonia and acetic acid in an embodiment. 2 is a graph showing the relationship between the elapsed time of spraying water at an initial humidity of 40% RH to 50% RH and the concentrations of ammonia and acetic acid in an embodiment. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying water at an initial humidity of 60% RH and the concentrations of ammonia and acetic acid. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying a sodium hypochlorite solution and the concentrations of ammonia and acetic acid at an initial humidity of 40% RH to 50% RH. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying a sodium hypochlorite solution at an initial humidity of 60% RH and the concentrations of ammonia and acetic acid. It is a graph showing the relationship between the elapsed time of spraying hypochlorous acid water and the concentrations of ammonia and acetic acid in an embodiment at an initial humidity of 40% RH to 50% RH. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying hypochlorous acid water at an initial humidity of 60% RH and the concentrations of ammonia and acetic acid. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying a citric acid buffer solution and the concentrations of ammonia and acetic acid at an initial humidity of 40% RH to 50% RH. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying a citric acid buffer solution and the concentrations of ammonia and acetic acid at an initial humidity of 60% RH. 2 is a graph showing the relationship between the elapsed time of spraying a diluted solution of a betaine compound and the concentrations of ammonia and acetic acid at an initial humidity of 40% RH to 50% RH in an embodiment. In an embodiment, it is a graph showing the relationship between the elapsed time of spraying a diluted solution of a betaine compound at an initial humidity of 60% RH and the concentrations of ammonia and acetic acid. In an embodiment, it is a graph showing the relationship between relative humidity and ammonia reduction rate 90 minutes after spraying water. In an embodiment, it is a graph showing the relationship between relative humidity and ammonia reduction rate 90 minutes after spraying a sodium hypochlorite solution and hypochlorous acid water. In an embodiment, it is a graph showing the relationship between relative humidity and ammonia reduction rate 90 minutes after spraying a citric acid buffer solution and a diluted betaine compound solution. In an embodiment, it is a graph showing the relationship between relative humidity and acetic acid reduction rate 90 minutes after spraying water. In an embodiment, it is a graph showing the relationship between relative humidity and acetic acid reduction rate 90 minutes after spraying a sodium hypochlorite solution and hypochlorous acid water. In an embodiment, it is a graph showing the relationship between relative humidity and acetic acid reduction rate 90 minutes after spraying a citric acid buffer solution and a diluted betaine compound solution.

An embodiment of the deodorizing method will be described below with reference to FIGS. 1 to 21.
FIG. 1 shows the configuration of a room 11 to be deodorized to be deodorized using the deodorization method in this embodiment. In this embodiment, the room 11 to be deodorized is assumed to be a living room, a hospital room, or the like in a recuperation ward. Then, the odor of excretion (ammonia odor and acetic acid odor) floating in the indoor space is deodorized from ammonia and acetic acid adhering to the surfaces (walls, floors, ceilings, etc.) of the buildings that make up these living rooms and hospital rooms.

(Explanation of the room to be deodorized)
The room 11 to be deodorized has a substantially rectangular parallelepiped shape and includes a floor 15, four walls 16, and a ceiling 17. An air conditioner (not shown) is attached to the inner wall of the wall 16. This air conditioner performs heating, cooling, humidification, and dehumidification of the room 11 to be deodorized. The air conditioner has a temperature sensor and a humidity sensor that respectively detect the current temperature and humidity of the room 11 to be deodorized, and an air conditioning function section that performs cooling, heating, humidification, and dehumidification.

The wall 16 is provided with a door 19, a window (not shown), and the like. A curtain (not shown) is installed on the indoor side of the window. Furthermore, the room 11 to be deodorized is equipped with a bed, a table, a chair, etc. (not shown).
A movable deodorizing device 20 is installed in the center of the floor 15 of the room 11 to be deodorized.

(Description of deodorizing device)
As shown in FIG. 2, the deodorizing device 20 includes a main body section 21, two spray sections 22, and a humidity measuring section M1. The main body part 21, the spray part 22, and the humidity measuring part M1 are fixed to a wheeled housing (not shown).

The main body section 21 includes a water tank 25, a chemical tank 26, a liquid switching valve 31, a compressor 35, a control unit 40, an operation section 45, and a display section 46. The water tank 25 and the chemical tank 26 are each placed on a weighing scale to check the remaining amount.

The water tank 25 stores water to be sprayed when the humidity is low at the start of deodorization.
The chemical liquid tank 26 stores a chemical liquid for spraying a chemical liquid used for deodorization. Details of this chemical solution will be described later.

The water tank 25 and the chemical liquid tank 26 are provided with flow meters (not shown) that measure the amount of spray (flow rate) of the chemical liquid supplied to the spray section 22 . Further, a water supply pipe and a chemical supply pipe are connected to the water tank 25 and the chemical solution tank 26, respectively. These water supply pipes and chemical liquid supply pipes are connected to a liquid switching valve 31.

The liquid switching valve 31 is connected to the two spray parts 22 via flexible liquid supply pipes (not shown). The liquid switching valve 31 switches the connection between the water supply pipe or the chemical liquid supply pipe and the liquid supply pipe, and supplies water or the chemical liquid to the spraying section 22 .

The compressor 35 generates compressed air and supplies it to the spray section 22 . This compressor 35 is connected to the spray section 22 via a gas supply valve (not shown) and a flexible gas supply pipe (not shown). This gas supply valve normally connects the compressor 35 and the spray section 22.
Details of the control unit 40, the operation section 45, and the display section 46 will be described later.

Each spray section 22 includes a two-fluid nozzle (not shown). As the two-fluid nozzle, a two-fluid siphon type spray nozzle is used that sprays a liquid in the form of a mist using compressed air. Specifically, Quick Fogger (trade name) manufactured by Spraying Systems Japan Co., Ltd. is used. This two-fluid nozzle can control the amount of liquid sprayed per hour by the air pressure of the supplied compressed air. The spray port of the two-fluid nozzle of this embodiment sprays mist having a particle size of 9 to 11 μm. For this reason, each spraying section 22 is supplied with compressed air from the compressor 35 and a chemical liquid from a chemical liquid tank. In this embodiment, the spray ports of the two-fluid nozzle are arranged to face a pair of walls that are arranged opposite to each other in the longitudinal direction of the room 11 to be deodorized.

(Chemical solution used)
In this embodiment, a chemical liquid containing at least one of a sodium hypochlorite solution, hypochlorous acid water, a betaine compound solution, and a citric acid solution as a main component is used as the chemical liquid.

(Control unit configuration)
The control unit 40 is connected to the humidity measuring section M1, and acquires a humidity measurement signal from the humidity measuring section M1 through wireless communication. Further, the control unit 40 is connected to a remote control section consisting of an operation section 45 and a display section 46 via wireless communication. The operation unit 45 is used to issue instructions to start deodorization, change the spray start humidity, etc. by remote control. The display section 46 is constituted by a display, and displays the humidity of the humidity measuring section M1, the set time, and the like.

The control unit 40 includes a humidification control section 41, a spray control section 42, and a system timer (not shown).
The humidification control unit 41 controls whether or not humidification is performed before spraying the chemical solution and the humidification process. For this reason, the humidification control unit 41 stores the spray start humidity for determining whether or not humidification is possible. In this embodiment, the spraying start humidity is, for example, 60% RH (60% relative humidity).

The spray control unit 42 executes a chemical spray process. For this reason, the spray control unit 42 stores the spray time and retention time from the spray port of the two-fluid nozzle of each spray unit 22. Here, as the spraying time, a time (for example, 5 minutes) during which the target relative humidity is equal to or higher than the target relative humidity (here, 80% RH) is used depending on the volume of the room 11 to be deodorized. As the holding time, a time (for example, 30 minutes) is used that allows a sufficient deodorizing effect to be obtained, based on the experimental results described below. This retention time is the time for the chemical solution to sufficiently react with ammonia and acetic acid, and is the time for the odor (concentration) to begin to rebound when water is sprayed.

(Deodorizing treatment)
Next, the deodorizing process performed using the deodorizing device 20 described above will be described using FIG. 3. In this case, as shown in FIG. 1, the deodorizing device 20 is placed at the center of the room 11 to be deodorized. Here, the spray ports of each spray unit 22 of the deodorizing device 20 are arranged to face the walls 16 arranged in the longitudinal direction of the room 11 to be deodorized. Then, the operator uses the operation unit 45 to instruct the start of the deodorizing process.

In response to this start instruction, the control unit 40 first executes a spraying start humidity determination process (step S1). Specifically, the humidification control section 41 of the control unit 40 acquires the current humidity from the humidity measurement section M1, and compares the acquired current humidity with the stored spray start humidity (60% RH). .

Then, the control unit 40 executes humidification processing as necessary (step S2). Specifically, when the current humidity is lower than the spray start humidity, the humidification control section 41 of the control unit 40 supplies water from the water tank 25 to the spray section 22 via the water supply pipe connected to the liquid supply pipe. Supply water. Further, the humidification control section 41 drives the compressor 35 to supply compressed air to the spray section 22 . Thereby, the spray unit 22 sprays water, thereby humidifying the room 11 to be deodorized. Then, when the current humidity periodically acquired from the humidity measuring section M1 reaches the spray start humidity, the humidification control section 41 stops the water spraying process by stopping the driving of the compressor 35. Note that if the current humidity is equal to or higher than the spray start humidity, the next process is executed without executing the humidification process.

Next, the control unit 40 executes a process of spraying the chemical solution up to the target relative humidity (step S3). Specifically, the spray control unit 42 of the control unit 40 switches the liquid switching valve 31 to connect the chemical liquid supply pipe to the liquid supply pipe instead of the water supply pipe, and transfers the chemical liquid from the chemical liquid tank 26 to the spray unit 22. supply. The spray control unit 42 then supplies compressed air to the spray unit 22 by driving the compressor 35, so that the spray unit 22 sprays the chemical solution.

Then, when the spraying time has elapsed, the spray control unit 42 uses the current humidity acquired from the humidity measurement unit M1 to check whether the target relative humidity (80% RH) has been reached. Here, if the target relative humidity has not been reached, an additional spraying process is performed in which the chemical solution is additionally sprayed for about 1 minute, for example, and the target relative humidity is reached using the current humidity from the humidity measuring section M1. The process of determining whether the When the target relative humidity is reached, the driving of the compressor 35 is stopped, thereby stopping the spraying process of the chemical solution.

After that, the control unit 40 executes a process of holding the target relative humidity for the holding time (step S4). Specifically, the spray control section 42 of the control unit 40 starts time measurement using a system timer, and measures until the retention time elapses. During this holding time, the spray control unit 42 repeatedly drives and stops the compressor 35 according to the current humidity periodically acquired from the humidity measuring unit M1, and the relative humidity of the room 11 to be deodorized is reduced to 80%. to be maintained. Specifically, when the current humidity is lower than the target relative humidity, the compressor 35 is driven to spray the chemical solution additionally for about 1 minute, and when the current humidity is higher than the target relative humidity, the compressor 35 is driven. Stops driving.

Then, when the holding time has elapsed and the compressor 35 is being driven, the spray control section 42 of the control unit 40 stops the compressor 35. Then, the spray control unit 42 switches the liquid switching valve 31 to connect the liquid supply pipe to the water supply pipe.
With the above steps, the deodorizing process is completed.

<Experiment>
The deodorizing method using the deodorizing device 20 described above was developed based on the knowledge of the following experimental results.
(Laboratory description)
First, the laboratory used to evaluate this deodorizing effect will be described using FIG. 4. FIG. 4 is a developed view of the laboratory 50 with the ceiling removed. The laboratory 50 has a rectangular parallelepiped shape surrounded by four walls 51, 52, 53, 54, a floor 55, and a ceiling (not shown). The laboratory 50 has an area of 18.6 m ² and a volume of 40.8 m ³ , and has a width L1 (=5.3 m), a depth W1 (=3.5 m), and a height H1 (=2.2 m). A door D1 is provided in the wall 54 of this laboratory. In the laboratory 50, the spray ports of the spray unit 22 of the deodorizing device 20 described above are arranged so as to face the walls 52 and 53, respectively. A desk 56 and two chairs 57 are arranged closer to the wall 52 than the deodorizing device 20. Further, in the laboratory 50, two curtains 58 and 59 are arranged near walls 52 and 53, respectively. Each curtain 58, 59 is a sample (odor source) to which ammonia and acetic acid are attached.

Here, two samples obtained by cutting a medical curtain into a predetermined size (for example, 0.3 m x 0.2 m) are used. An acetic acid-attached curtain is created by dropping 3.0 ml of acetic acid onto one sample. An ammonia adhesion curtain is created by dropping 6.0 ml of ammonia onto the other sample. This dropping is performed in a fume hood, and the sample after dropping is placed in a sealed bag and transported to the laboratory 50.

In the laboratory 50, temperature and humidity sensors P1, P2, P3, P4, P5, P6, P7, P8, P9, and P10 were placed at each position shown in FIG. Then, in the laboratory 50, each component gas is measured using a detection tube 60 at the lower end of the wall 52 on the wall 54 side.

(experimental method)
In the experiment, two samples each (an ammonia-adhered curtain and an acetic acid-adhered curtain) were hung near walls 52 and 53 in the laboratory 50, respectively.

Then, by leaving it for one hour, the laboratory room 50 is filled with the odor of ammonia and acetic acid. At this time, by operating the electric fan 62 placed near the deodorizing device 20, the concentration of ammonia and acetic acid odors in the room is made uniform.

After leaving it for one hour, the concentrations of ammonia and acetic acid are measured using the detection tube 60. When the initial concentration (10 to 30 ppm) is reached, the electric fan 62 is stopped and the chemical solution is sprayed under the following test conditions.

After installing the curtain, the ammonia concentration and acetic acid concentration in the laboratory 50 were measured using the detection tube 60 at 10 minute intervals from immediately after the spraying until 90 minutes after the spraying, and the attenuation of the concentration of each component was evaluated.
Five types of chemical solutions shown in Table 1 below were used for spraying. Moreover, the reaction system of each chemical solution with ammonia and acetic acid is shown in FIG.

Hypochlorous acid water is produced by adjusting a sodium hypochlorite solution with a hypochlorous acid concentration of 200 ppm to weak acidity by adding 3% hydrochloric acid. In this hypochlorous acid aqueous solution, the proportion of non-dissociated HClO is greater than that of dissociated ClO. The deodorizing mechanism regarding the deodorizing effect of sodium hypochlorite solution and hypochlorous acid water is thought to be mainly an oxidation reaction. However, we confirmed the effects of the contained components (dissociated type, non-dissociated type, and differences in pH (weakly alkaline, weakly acidic)).

In addition, a citric acid buffer (citric acid solution) and a 50-fold diluted solution of betaine (betaine compound solution) reduce odor through an acid-alkali reaction (neutralization reaction) with alkaline malodors such as ammonia. Since the betaine compound solution is a double-sided surfactant, it is thought to be effective against not only alkaline odors but also acidic odors such as methyl mercaptan, hydrogen sulfide, and acetic acid.

(Spraying conditions)
Three conditions are used for the initial relative humidity (before spraying): approximately 30% RH, 40 to 50% RH, and approximately 60% RH. The temperature of the laboratory 50 was set at 25°C to 28°C.

Since the laboratory 50 had high heat insulation and a high degree of airtightness, almost no change in relative humidity was observed from immediately after spraying until 90 minutes had elapsed. All chemical solutions were sprayed so that the relative humidity after spraying was approximately 80% RH. In this experiment, because the target relative humidity (80% RH) was reached after 4 minutes of spraying based on the capacity of the laboratory 50 and the spraying speed from the spraying section 22, 4 minutes of spraying was performed. In addition, in this case, the amount of the chemical solution used was around 320 g for any of the chemical solutions.

(Experimental result)
6 to 15 show the concentration changes of each component from immediately after spraying (60 minutes after the start of measurement) to 90 minutes after (150 minutes after the start of measurement). FIGS. 6 and 7 show the case where water is sprayed, and the case where the RH before the spraying is 40 to 50% RH and the case where the RH before the spraying is about 60% are shown, respectively. FIGS. 8 and 9 show the case where the sodium hypochlorite solution shown in Table 1 is sprayed, and respectively show the case where the RH before spraying is 40 to 50% RH and the case where the RH before spray is about 60% RH. 10 and 11 show the case where the hypochlorous acid water shown in Table 1 is sprayed, and respectively show the case where the RH before spraying is 40 to 50% RH and the case where the RH is about 60% before spraying. FIGS. 12 and 13 show the case where the citric acid buffer solution shown in Table 1 is sprayed, and shows the case where the RH before spraying is 40 to 50% RH, and the case where the RH before spraying is about 60% RH, respectively. FIGS. 14 and 15 show the case where a 50-fold diluted solution of the betaine compound shown in Table 1 is sprayed, and shows the case where the RH before spraying is 40 to 50% RH, and the case where the RH before spraying is about 60% RH, respectively.

When water was sprayed, the concentrations of both ammonia and acetic acid decreased temporarily immediately after spraying, but they tended to increase over time, regardless of the relative humidity before spraying. In the case of this water spray, it is thought that after the odor components in the air dissolve in water, the concentration in the air decreases, and then the concentration increases due to rebound.

On the other hand, when each drug was sprayed, the concentrations of ammonia and acetic acid decreased immediately after spraying, regardless of the type of sprayed drug. Furthermore, for any of the chemical solutions, the rebound observed with water spraying was not observed when the RH before spraying was 40 to 50% RH and when the RH before spraying was approximately 60% RH in Figures 8 to 15. . In addition, if the relative humidity before spraying is 30%, the relative humidity after spraying is low, so the sprayed chemicals cannot sufficiently react with the malodorous components attached to the curtain, and the concentration of ammonia and acetic acid gradually decreases over time. It was rising.

(Considerations on ammonia reduction rate)
Further, FIGS. 16 to 18 show the relative humidity and ammonia reduction rate 90 minutes after spraying. The relative humidity is the average value of the humidity measured by the temperature and humidity sensors P1 to P10. The ammonia reduction rate is the ratio of the ammonia concentration at this time to the initial ammonia concentration immediately before spraying. Note that these ammonia concentrations are the ammonia concentrations tested in the detection tube 60 in FIG. 4. Here, Figure 16 shows the case of spraying water, Figure 17 shows the case of spraying sodium hypochlorite solution and hypochlorous acid water, and Figure 18 shows the 50-fold dilution of citric acid buffer and betaine compound. This shows the case where the liquid is sprayed.

From Figures 16 to 18, when spraying diluted solutions of sodium hypochlorite solution, hypochlorous acid water, and betaine compounds, the rate of ammonia reduction is low when the relative humidity after spraying is low, but the relative humidity after spraying is low. The higher the value, the higher the ammonia reduction rate. By increasing the RH to 80% or more, the ammonia reduction rate increased to 80 to 90% or more. Therefore, when deodorizing the environmental surfaces throughout the room, it is important to keep the relative humidity at 80% RH or higher.

Furthermore, as shown in FIG. 18, the citric acid buffer had a high ammonia reduction rate of 80 to 100% when the relative humidity after spraying was 80% or higher. When spraying the citric acid buffer, a new odor other than ammonia was slightly generated, but the reaction product was unknown.

From the above, it was observed that the deodorizing effect of ammonia tends to be higher as the relative humidity after spraying is higher. Then, by spraying the sodium hypochlorite solution until the RH reaches 80%, the reduction rate of the ammonia concentration from the initial level becomes 80% or more. Furthermore, even when the sprayed chemicals were changed to hypochlorous acid water, citric acid buffer, or diluted betaine compound, similar ammonia deodorizing effects were observed.

Therefore, in order to deodorize the ammonia odor so that the ammonia concentration is less than 20%, spray a sodium hypochlorite solution, hypochlorous acid water, citric acid buffer, or diluted betaine compound solution. to set the target relative humidity to 80%RH or higher. In this case, if the time period during which the inside of the laboratory 50 is brought to the target relative humidity of 80% RH is short, the chemical reaction between ammonia and the components of the chemical solution is insufficient. Therefore, ammonia can be reduced by keeping the space at a target relative humidity of 80% RH for a certain period of time (holding time). Here, as shown in FIGS. 6 and 7, a rebound in the ammonia concentration during water spraying occurs approximately 30 minutes after the water spraying (90 minutes elapsed time). Although the rebound in water concentration is not a chemical reaction, it is the reaction time when substances come into contact with each other, so the time until the rebound occurs is used as the retention time.

(Considerations on acetic acid reduction rate)
19 to 21 show the relationship between the acetic acid reduction rate and the relative humidity (value after 90 minutes of spraying) compared to immediately before spraying, 90 minutes after spraying. Here, Figure 19 shows the case of spraying water, Figure 20 shows the case of spraying sodium hypochlorite solution and hypochlorous acid water, and Figure 21 shows the 50-fold dilution of citric acid buffer and betaine compound. This shows the case where the liquid is sprayed.

From FIGS. 19 to 21, in the case of acetic acid, when a diluted solution of a betaine compound was sprayed, the influence of the relative humidity after spraying (the higher the relative humidity after spraying, the higher the deodorizing effect) was confirmed. In particular, by increasing the RH to 80% or more, the acetic acid reduction rate increased to around 90%. Furthermore, in the case of sodium hypochlorite solution, the acetic acid reduction rate increased to 80% at RH of 80% or more. Hypochlorous acid water showed variations in acetic acid reduction rate.

Furthermore, when a citric acid buffer solution was sprayed, the acetic acid reduction rate was 80% to 93% at a relative humidity of 63% to 80% after spraying, and the deodorizing effect of acetic acid was also high. In this case, a slight new odor was generated, but as with the ammonia reaction, the reaction product is unknown.

As described above, when spraying a dilute solution of a betaine compound, a correlation was observed between acetic acid and the relative humidity and deodorizing effect after spraying. By spraying until the relative humidity reached 80% RH, the rate of decrease in acetic acid concentration from the initial concentration was 80% or more.

Therefore, in order to deodorize the acetic acid odor so that the acetic acid concentration is less than 20%, spray a sodium hypochlorite solution, hypochlorous acid water, a citric acid buffer solution, or a diluted betaine compound solution. , 80%RH or higher. In this case, as in the case of ammonia, if the time period during which the inside of the laboratory 50 is brought to the target relative humidity of 80% RH is short, the chemical reaction with the acetic acid component will be insufficient. Therefore, acetic acid is reduced by maintaining the space at a target relative humidity of 80% RH for a certain period of time (holding time). In this case as well, the time until the rebound of the acetic acid concentration occurs during water spraying shown in FIGS. 6 and 7 is used as the retention time.

(effect)
A sodium hypochlorite solution is sprayed until the relative humidity reaches 80% or more, and then this relative humidity is maintained for a certain period of time. This causes an oxidation reaction between sodium hypochlorite and ammonia in the sodium hypochlorite solution, as well as a reaction between sodium hydroxide in the sodium hypochlorite solution and acetic acid, which is the cause of the sour odor in the room. A neutralization reaction occurs. Therefore, the concentration of ammonia and acetic acid in the air decreases, and the amount of ammonia and acetic acid adhering to the surfaces of the room 11 to be deodorized, such as the floor 15, walls 16, and ceiling 17, decreases.

According to this embodiment, the following effects can be obtained.
(1) In this embodiment, a chemical solution is sprayed until the relative humidity reaches 80% or more, and then this relative humidity is maintained for a holding time. Here, as the chemical liquid, a chemical liquid containing at least one of a sodium hypochlorite solution, hypochlorous acid water, a betaine compound solution, and a citric acid solution as a main component is used. Thereby, the concentrations of ammonia and acetic acid can be reduced, so that excretion odors including ammonia odor, acetic acid odor, etc. in the room 11 to be deodorized can be reduced. Here, deodorization by spraying a chemical solution is thought to take longer for the chemical reaction than disinfecting by spraying a chemical solution, so it is more reliable to deodorize by maintaining a relative humidity of 80% or more for a certain period of time. can.

(2) In this embodiment, 30 minutes is used as the holding time after the relative humidity reaches 80% or more by spraying the chemical solution. This holding time is the time during which the chemical solution reacts sufficiently with ammonia and acetic acid, and the holding time is used as the time until rebound of the ammonia concentration or acetic acid concentration occurs during water spraying. Since the rebound of water concentration is the reaction time when substances are in contact with each other, odor can be eliminated by sufficiently reacting the chemical solution with ammonia and acetic acid, which are sources of odor.

(3) In this embodiment, a chemical liquid containing at least one of a sodium hypochlorite solution, hypochlorous acid water, a betaine compound solution, and a citric acid solution as a main component is sprayed. Since either chemical solution has less influence on the human body than spraying high-concentration ozone, there is no need to provide a screen or the like at the boundary between the door D1 and the wall of the room 11 to be deodorized. Therefore, deodorization can be easily performed.

This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- In the above embodiment, the relative humidity after spraying was maintained at 80% for a certain period of time (holding time). Here, 30 minutes was used as the holding time, but the holding time is not limited to this time. In FIGS. 8 to 15, a decrease in concentration is observed immediately after the chemical solution is sprayed, and almost no change in concentration is observed thereafter. From this, the holding time may be a time (time shorter than 30 minutes) during which the concentration of ammonia odor or acetic acid odor decreases to a constant value over a long period of time after spraying. Further, the holding time may be changed depending on, for example, the size of the room 11 to be deodorized, the room temperature of the room 11 to be deodorized, the density of the odor (the concentration of ammonia or acetic acid), and the like.

- In the above embodiment, when ammonia is deodorized by spraying a sodium hypochlorite solution, alkalinity is preferable. For example, in a sodium hypochlorite solution, the pH is not limited to 8.9 used in the experiment, but it is preferable to use a pH in the range of 6.5 to 9.5.

- In the above embodiment, after water was sprayed (humidified) to the spray start humidity, a chemical solution was sprayed to reach the target relative humidity of 80% RH, which was maintained for a certain period of time. When the humidity at the start of deodorization is lower than the humidity at the start of spraying, a chemical solution may be sprayed instead of water. In this case, a deodorizing device 20 without the water tank 25 or liquid switching valve 31 can be used.
- In the above embodiment, one type of chemical solution used in the deodorization experiment was sprayed. If there is no problem in mixing the plurality of chemical solutions used in the deodorizing experiment, they may be used in combination.

D1...Door, H1...Height, L1...Width, M1...Humidity measuring section, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10...Temperature and humidity sensor, W1...Depth, 11...Delete Odor target room, 15, 55... Floor, 16, 51, 52, 53, 54... Wall, 17... Ceiling, 19... Door, 20... Deodorizing device, 21... Main unit, 22... Spraying part, 25... Water tank , 26... Chemical tank, 31... Liquid switching valve, 35... Compressor, 40... Control unit, 41... Humidification control section, 42... Spray control section, 45... Operation section, 46... Display section, 50... Laboratory, 56... Desk, 57...Chair, 58, 59...Curtain, 60...Detection tube, 62...Fan.

Claims (5)

A deodorizing method for eliminating at least one of ammonia odor and acid odor attached to indoor surfaces, the method comprising:
Using a two-fluid nozzle, apply a chemical solution containing at least one of sodium hypochlorite solution, hypochlorous acid water, betaine compound solution, and citric acid solution as a main component until the relative humidity in the room reaches 80% or more. A deodorizing method characterized by spraying and maintaining a relative humidity of 80% or more after spraying for a retention time. When the chemical solution is a sodium hypochlorite solution, an oxidation reaction between sodium hypochlorite in the sprayed sodium hypochlorite solution and ammonia, which is the cause of the ammonia odor in the indoor space, and the spray 2. The deodorizing method according to claim 1, wherein a neutralization reaction is performed between sodium hydroxide in the sodium hypochlorite solution and acetic acid, which is the cause of the sour odor in the room. When the chemical solution is hypochlorous acid water, an oxidation reaction is performed between the hypochlorous acid in the sprayed hypochlorous acid water and ammonia, which is the source of the ammonia odor in the room. The deodorizing method according to claim 1. When the chemical solution is a betaine compound solution, a neutralization reaction between the betaine compound in the sprayed betaine compound solution and ammonia, which is the source of the ammonia odor in the room, and the betaine compound in the sprayed betaine compound solution. 2. The deodorizing method according to claim 1, wherein a neutralization reaction with acetic acid, which is a cause of acid odor in indoor space, is carried out. 1. When the chemical solution is a citric acid solution, a neutralization reaction is performed between the citric acid in the sprayed citric acid solution and ammonia, which is the source of the ammonia odor in the room. The deodorizing method described in.

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