JP6283551B2 - Chlorine dioxide gas generator and method - Google Patents

Description

The present invention relates to an apparatus and method for generating chlorine dioxide gas used for disinfection, microbial decontamination, and the like.

  Chlorine dioxide gas is used, for example, in the manufacture of pharmaceuticals and foods, in rooms where sterility or semi-sterility is required, in spaces where isolators are required, disinfection of spaces such as isolators and in surfaces, and in the decontamination of microorganisms. For example, Patent Document 1 is disclosed as a conventional apparatus for producing chlorine dioxide gas. In this chlorine dioxide production apparatus, two types of raw material chemical solutions, a chlorite solution and an acid solution, are continuously supplied to the reaction vessel and mixed, and the chlorine dioxide gas generated by the reaction is dissolved in the chemical solution. . Then, in order to take out chlorine dioxide gas dissolved in the chemical solution, air is aerated in the chemical solution. Alternatively, chlorine dioxide gas is continuously taken out by supplying air to the holder while supplying the chemical solution to the holder. Further, Patent Document 2 discloses a manufacturing apparatus that generates chlorine dioxide water by stirring and mixing a chlorite solution and an acidic liquid. Further, Patent Document 3 discloses an apparatus for diffusing chlorine dioxide gas generated by supplying sodium chlorite and an acidic liquid to a container disposed in an open container with a blower 16.

Japanese Patent Laid-Open No. 2005-53741 JP-A-11-92104 JP 2010-207539 A

  However, the technique of Patent Document 1 extracts chlorine dioxide gas from the chemical solution by aeration into the chemical solution or by blowing air to the holding body. An unreacted acid chemical solution is always mixed in the chemical solution, which is misted by an operation such as aeration and mixed with chlorine dioxide gas and taken out. Since the acid mist is extremely corrosive, there is a problem that when supplied to the target room for disinfection / decontamination, the surface of the target room or the article is corroded. Further, the moisture in the chemical solution is similarly misted or evaporated by the operation such as aeration, so that the chlorine dioxide gas taken out becomes highly humid. Chlorine dioxide gas is known to increase the disinfection and decontamination effect in a high humidity environment, but also increases the risk of corrosion. Therefore, in the indoor disinfection and decontamination, an optimum combination condition of chlorine dioxide gas concentration and humidity is required, and in order to adjust the optimum combination condition, adjustment of chlorine dioxide gas concentration and adjustment of humidity are required. It is necessary to be independent. However, the conventional method of increasing the humidity of chlorine dioxide gas is extremely difficult to independently adjust the chlorine dioxide gas concentration and humidity. For example, it may be possible to capture mist mixed with chlorine dioxide gas through a filter or the like. However, if a filter is used, pressure loss will occur and the blowing power will increase, a large blower will be required, and the running cost will increase. End up.

  In addition, the technique of patent document 2 is related with the manufacturing apparatus which produces | generates chlorine dioxide water, and taking out chlorine dioxide gas is not assumed by patent document 2. FIG. Moreover, the technique of patent document 3 installs an open container in space, such as a room | chamber interior, and diffuses the chlorine dioxide gas generated in the container in space.

An object of the present invention is to provide a chlorine dioxide gas generator and a generation method that can extract chlorine dioxide gas at low humidity with little mixing of acidic mist.

In order to achieve such an object, according to the present invention, a chlorine dioxide gas generator that supplies a chlorite solution and an acidic liquid to a sealed reaction vessel and generates chlorine dioxide gas by a chemical reaction between the two. A suction pipe for taking air into the reaction vessel, which is opened above the liquid level of the mixed solution of the chlorite solution and the acidic solution stored at the bottom of the reaction vessel, and the bottom of the reaction vessel. the liquid level of the mixed solution reservoir was chlorite solution and an acidic solution is open at the upper, provided with a discharge pipe for discharging chlorine dioxide gas generated in the reaction vessel to the outside, the outside air suction uptake inside above the reaction vessel through pipe, and wherein the upper portion inside atmosphere of the reaction vessel be discharged to the outside through the discharge pipe, chlorine dioxide gas generator is provided
According to the present invention, there is also provided a chlorine dioxide gas generation method in which a chlorite solution and an acidic liquid are supplied to a sealed reaction vessel, and chlorine dioxide gas is generated by a chemical reaction between the two. Through the suction pipe opened above the liquid level of the mixed solution of the chlorite solution and the acidic solution stored at the bottom of the reaction vessel, the solution is taken into the upper part of the reaction vessel and stored at the bottom of the reaction vessel. A chlorine dioxide gas generation method characterized by discharging the atmosphere above the inside of the reaction vessel to the outside through a discharge pipe opened above the liquid level of the mixed solution of the chlorite solution and the acidic liquid. Provided.

  In the chlorine dioxide gas generator of the present invention, a chlorite solution and an acidic liquid are supplied to a reaction vessel, and chlorine dioxide gas generated by the chemical reaction between the two is not aerated in the mixed solution. Since it is taken out from the reaction vessel, chlorine dioxide gas can be taken out at low humidity with little mixing of acidic mist.

  In this chlorine dioxide gas generator, inside the reaction vessel, there is a small vessel arranged above the liquid level of the mixed solution of chlorite solution and acidic solution, and the sub- vessel supplied to the reaction vessel. The chlorate solution and the acid solution may be supplied to the small container and mixed first, and then overflowed and stored in the bottom of the reaction container. In addition, a pump adjusting mechanism for controlling the supply of chlorite solution and acid solution, or disinfection / decontamination so that the concentration of chlorine dioxide gas discharged from the reaction vessel does not exceed a predetermined upper limit concentration You may provide the pump adjustment mechanism which controls supply of a chlorite solution and an acidic liquid so that the density | concentration of the chlorine dioxide gas in a room may not exceed a predetermined | prescribed upper limit density | concentration. Moreover, you may use the alkaline substance in any one of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium hydrogencarbonate as a reaction terminator of chlorine dioxide gas generation reaction.

  Further, a mixed solution recovery tank is installed below the reaction vessel, and a lower end of a drainage pipe connected to the lower surface of the reaction vessel is connected to the recovery tank, An open / close valve is provided that closes when energized and opens when a power failure occurs. The recovery tank is filled with a reaction stopper made of carbonate or bicarbonate alkaline substance, and is stored in the bottom of the reaction vessel. The upper side of the liquid level and the upper side of the liquid level of the mixed solution recovered in the recovery tank may be communicated by a connecting pipe. In this case, the open / close valve that closes when the power is supplied and opens when the power fails is a normally open electromagnetic valve, for example. The diameter of the connecting pipe is preferably in the range of 1 m / s to 20 m / s when the air volume corresponding to the volume of the reaction vessel is passed in 1 minute.

  According to the present invention, since chlorine dioxide gas can be taken out at low humidity with little mixing of acidic mist, there is no risk of corrosion, and reliable and safe chlorine dioxide gas that does not interfere with humidity adjustment is desired region. It becomes possible to supply to. It is possible to disinfect and decontaminate indoor surfaces and articles in a safe state free from corrosion by acid mist. In addition, since the disinfection / decontamination system incorporating the apparatus of the present invention can control the indoor gas concentration and humidity independently, there is no risk of corrosion under the optimum combination conditions of chlorine dioxide gas concentration and humidity. Decontamination can be performed. In particular, a mixed solution recovery tank connected by drainage pipes is installed below the reaction vessel, and an open / close valve is provided in the drainage tank that closes when energized and opens when a power failure occurs. By putting a reaction terminator composed of a salt alkaline substance and connecting the reaction vessel and the recovery tank through a connecting pipe, the device can be safely put into a stopped state without blowing by an emergency power source, and the cost is reduced. Can be reduced.

It is explanatory drawing of the chlorine dioxide gas generator concerning embodiment of this invention. 1 is a schematic diagram of a disinfection / decontamination system that incorporates a chlorine dioxide gas generator according to an embodiment of the present invention and performs indoor disinfection / decontamination. FIG. It is a schematic diagram of the disinfection and decontamination system which installed the air blower in the suction pipe. It is explanatory drawing of the chlorine dioxide gas generator concerning embodiment of this invention which enabled it to change to a stop state safely at the time of a power failure. 3 is a graph showing a criminal change in indoor gas concentration in Example 1. 4 is a graph showing a criminal change in indoor humidity in Example 1. 6 is a graph showing a criminal change in indoor gas concentration in Example 2. 6 is a graph showing a criminal change in indoor humidity in Example 2.

  Embodiments of the present invention will be described. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  As shown in FIG. 1, a chlorine dioxide gas generator 1 according to an embodiment of the present invention includes a sealed reaction vessel 10, and a chlorite solution tank 11 is provided outside the reaction vessel 10. And an acidic liquid tank 12 is provided. The chlorite solution tank 11 is filled with a chlorite solution a such as a sodium chlorite aqueous solution. The reaction vessel 10 and the chlorite solution tank 11 are connected by a chlorite solution supply pipe 13, and a liquid feed pump 14 and an electromagnetic valve 15 are installed in the chlorite solution supply pipe 13. When the electromagnetic valve 15 is opened and the liquid feed pump 14 is operated, the chlorite solution a in the chlorite solution tank 11 is supplied to the reaction vessel 10 through the chlorite solution supply pipe 13.

  The acidic liquid tank 12 is filled with an acidic liquid b such as, for example, malic acid, citric acid or sulfuric acid. The reaction vessel 10 and the acidic liquid tank 12 are connected by an acidic liquid supply pipe 20, and a liquid feed pump 21 and an electromagnetic valve 22 are installed in the acidic liquid supply pipe 20. When the electromagnetic valve 22 is opened and the liquid feed pump 21 is operated, the acidic liquid b in the acidic liquid tank 12 is supplied to the reaction vessel 10 through the acidic liquid supply pipe 20.

  A small container 25 is installed inside the reaction container 10. The outlet of the chlorite solution supply pipe 13 and the outlet of the acidic liquid supply pipe 20 are both located above the small container 25 inside the reaction vessel 10. For this reason, as described above, the chlorite solution a supplied into the reaction vessel 10 by the operation of the liquid feeding pump 14 and the acidic liquid b supplied into the reaction vessel 10 by the operation of the liquid feeding pump 21 are initially After the chlorite solution a and the acidic solution b are mixed in the small container 25, the mixed solution c of both overflows from the small container 25 and is stored at the bottom of the reaction container 10. It is done. The volume of the small container 25 is, for example, about 1 minute from when the chlorite solution a and the acidic liquid b are supplied to the small container 25 until the mixed solution c overflows from the small container 25. Is set as follows. The small container 25 is disposed above the liquid level of the mixed solution c stored at the bottom of the reaction container 10.

  Inside the reaction vessel 10, a stirrer 30 for stirring the mixed solution c stored at the bottom of the reaction vessel 10 and a thermometer 31 for measuring the temperature of the mixed solution c are provided. A part of the heat transfer tube 36 of the temperature control mechanism 35 is exposed in the mixed solution c stored at the bottom of the reaction vessel 10. The heat transfer tube 36 constitutes a closed circuit for circulating the heat medium between the heat exchanger 37 and the reaction vessel 10, and the heat medium is circulated in the heat transfer tube 36 by the operation of the pump 38. .

  The heat exchanger 37 is connected to a heat source circuit 39 that circulates the heat source between the heat source circuit 42 and the heat source circuit 42, and the temperature of the heat source circuit 42 is controlled by the operation of the pump 40 provided in the heat source circuit 39. The heat source thus supplied is supplied to the heat exchanger 37 through the heat source circuit 39. In the heat exchanger 37, the heat medium in the heat transfer pipe 36 is temperature-controlled by exchanging heat with the heat source adjusted in temperature by the cold / hot heat source apparatus 42, and the heat medium thus adjusted circulates in the heat transfer pipe 36. Thus, it comes into thermal contact with the mixed solution c stored at the bottom of the reaction vessel 10.

  The operation of the pump 38 provided in the heat transfer tube 36 is controlled by a pump adjustment mechanism 41, and the pump adjustment mechanism 41 stores the mixed solution c stored at the bottom of the reaction vessel 10 measured by the thermometer 31. Temperature is entered. Based on the temperature of the mixed solution c input from the thermometer 31, the pump adjustment mechanism 41 controls the operation of the pump 38 to adjust the flow rate of the heat medium circulating in the heat transfer pipe 36. The mixed solution c stored at the bottom is kept at a desired temperature.

  Below the reaction vessel 10, a collection tank 45 for the mixed solution c is installed. A lower end of a drainage pipe 46 connected to the lower surface of the reaction vessel 10 is connected to the recovery tank 45, and an open / close valve 47 is provided in the drainage pipe 46. By opening the opening / closing valve 47, the mixed solution c stored at the bottom of the reaction vessel 10 is recovered by its own weight through the drainage pipe 46 into the recovery tank 45.

  A suction pipe 50 and a discharge pipe 51 are connected to the upper surface of the reaction vessel 10. Both the suction pipe 50 and the discharge pipe 51 are open above the liquid level of the mixed solution c stored at the bottom of the reaction vessel 10. For the suction pipe 50 and the discharge pipe 51, for example, a PVC pipe is used. An air flow meter 52 is installed in the suction pipe 50. The discharge pipe 51 is provided with a blower 53 and a chlorine dioxide gas concentration meter 54. With the operation of the blower 53, external air is taken into the upper part of the reaction vessel 10 through the suction pipe 50, and the atmosphere (chlorine dioxide gas d) inside the reaction container 10 is discharged to the outside through the discharge pipe 51. The At that time, the air volume of the air taken into the reaction container 10 from outside through the suction pipe 50 is measured by the anemometer 52 and input to the pump adjusting mechanism 55. Further, the concentration of chlorine dioxide gas d discharged from the upper inside of the reaction vessel 10 to the outside is measured by a chlorine dioxide gas concentration meter 54 and input to the pump adjusting mechanism 55.

In the chlorine dioxide gas generator 1 configured as described above, when the electromagnetic valve 15 is opened and the liquid feed pump 14 is operated, the chlorite solution a in the chlorite solution tank 11 is converted to chlorite. It is supplied to the reaction vessel 10 through the salt solution supply pipe 13. Further, when the electromagnetic valve 22 is opened and the liquid feed pump 21 is operated, the acidic liquid b in the acidic liquid tank 12 is supplied to the reaction vessel 10 through the acidic liquid supply pipe 20. Thus, in the reaction vessel 10, the chlorite solution a and the acidic solution b are mixed, and both chemically react to generate chlorine dioxide gas (ClO2) d. In this case, the generated chlorine dioxide gas d is first dissolved in the mixed solution c, and as the reaction proceeds, the dissolved gas concentration in the mixed solution c rises, and eventually the dissolved gas molecules with the concentration difference at the gas-liquid interface as a driving force. Moves to the gas phase above the surface of the chemical. The chlorite solution a is, for example, an aqueous sodium chlorite solution, the acidic solution b is, for example, a malic acid solution, and the reaction formula is as follows.
5NaClO2 + 2HOOC-CH (OH) -CH2-COOH → 2NaOOC-CH (OH) -CH2-COONa + 4ClO2 + NaCl + 2H2O

  Here, in the reaction vessel 10, the chlorite solution a and the acid solution b are first supplied to the small vessel 25 and mixed. For example, the upper end of the peripheral wall of the small container 25 is positioned from the liquid level of the mixed solution c in the reaction container 10. In the small container 25, the unreacted chlorite solution a and the acidic solution b are mixed in a fresh state in which the mutual concentrations are still high, so that the chlorine dioxide gas d can be generated efficiently. Since the time from when the chlorite solution a and the acidic solution b are supplied to the small container 25 until the mixed solution c overflows from the small container 25 is set to about 1 minute, For about 1 minute, the chlorite solution a and the acid solution b react with high efficiency, and high-concentration chlorine dioxide gas d can be generated.

  Thus, after the chlorite solution a and the acidic liquid b are mixed in the small container 25 and the chlorine dioxide gas d is efficiently generated, the mixed solution c of both overflows from the small container 25, and the reaction container 10 Stored at the bottom. The chlorite solution a and the acid solution b (mixed solution c) mixed in the small container 25 are delivered to the bottom of the reaction container 10 in about 1 minute and are quickly replaced. The chlorite solution a and the acid solution b can be reacted in a high concentration state. If there is no small container 25 and the chlorite solution a and the acid solution b are received at the bottom of the reaction vessel 10 from the beginning, the supplied fresh chlorite solution a and the acid solution b are reacted. The reaction mixture that has already been stored at the bottom of the container 10 is immediately diluted with the mixed solution c, and the chlorine dioxide gas d cannot be generated efficiently.

  The temperature of the mixed solution c received at the bottom of the reaction vessel 10 is measured by the thermometer 31 and input to the pump adjustment mechanism 41. The pump adjustment mechanism 41 controls the operation of the pump 38 based on the temperature of the mixed solution c, and the heat medium flow rate circulating in the heat transfer tube 36 is adjusted. Thus, the temperature of the mixed solution c stored at the bottom of the reaction vessel 10 is adjusted to a temperature suitable for the reaction by the temperature adjustment mechanism 35. Furthermore, it stirs with the stirrer 30, and reaction of the mixed solution c is accelerated | stimulated. The generation rate of the chlorine dioxide gas d is faster as the temperature of the mixed solution c is higher, and is slower as the temperature of the mixed solution c is lower. Therefore, the temperature adjustment mechanism 35 eliminates the influence of the surrounding temperature environment, and a predetermined generation rate is obtained. Secure. The temperature of the mixed solution c is preferably 10 ° C to 60 ° C, more preferably 20 ° C to 40 ° C. It should be noted that a high temperature of 50 ° C. or higher is acceptable, but if the temperature is too high, the material and structure of the reaction vessel 10 and the like must be able to withstand the high temperature. In addition, by providing a temperature control mechanism in the chlorous acid solution tank 11 and the acidic liquid tank 12, for example, one of the chlorite solution a and the acidic liquid b is set to a high temperature and the other is set to a low temperature. You may make it become the temperature of.

  Then, in a state where chlorine dioxide gas d is stored inside the reaction vessel 10, external air is taken into the upper part of the reaction vessel 10 through the suction pipe 50 by the operation of the blower 53, and the upper inside of the reaction vessel 10. Atmosphere (chlorine dioxide gas d) is discharged to the outside through the discharge pipe 51. Inside the reaction vessel 10, the chlorine dioxide gas d moves from the liquid level of the mixed solution c stored in the small vessel 25 and the liquid level of the mixed solution c stored at the bottom of the reaction vessel 10 to the gas phase portion. . By passing the gas phase portion inside the reaction vessel 10 through the suction pipe 50 and the discharge pipe 51 connected to the upper surface of the reaction vessel 10, the chlorine dioxide gas d moved to the gas phase portion of the reaction vessel 10 is aerated. Without being aerated, it is continuously carried out from the discharge pipe 51 as needed.

  Note that, inside the reaction vessel 10, when the chlorine dioxide gas d moves from the liquid level of the mixed solution c stored in the small vessel 25 to the gas phase portion, and when the mixed solution c is stored at the bottom of the reaction vessel 10. When the chlorine dioxide gas d moves from the liquid level to the gas phase, water molecules move from the liquid level to the gas phase due to the difference in concentration at the gas-liquid interface. However, in the case of water molecules, the amount of migration is very small in the temperature range of the present invention and the ratio of the surface area of the mixed solution c to the amount of aeration air, and the chlorine dioxide gas d carried out of the reaction vessel 10 to the outside is almost humidity. Does not rise.

  As a result, the low-humidity chlorine dioxide gas d with little mixing of acidic mist can be taken out of the reaction vessel 10. Thus, by supplying chlorine dioxide gas d, for example, in the production of pharmaceuticals and foods, in a room where sterility or semi-sterility is required, space such as an isolator or the surface in the space, disinfection of a desired location, Decontamination of microorganisms can be performed. Since the extracted chlorine dioxide gas d has a low humidity, it is easy to control the humidity of the chlorine dioxide gas d used for disinfection, microbial decontamination, etc., and the risk of corrosion can be avoided. Optimal combination conditions can be realized.

  As mentioned above, although an example of embodiment of this invention was demonstrated, this invention is not limited to the illustrated form. The chlorite solution a is preferably an aqueous solution of an alkali metal salt or alkaline earth metal salt of chlorite, such as an aqueous solution of sodium chlorite, an aqueous solution of potassium chlorite, or an aqueous solution of calcium chlorite. In addition, as acids used in the acidic liquid b, for example, sulfuric acid, phosphoric acid, malic acid, oxalic acid, citric acid, tartaric acid, fumaric acid, succinic acid, gluconic acid, lactic acid, adipic acid and the like are low in volatility. Acids that do not cause corrosion in the dyed room are desirable. In any case, by using a low-volatility acidic liquid having a pH of 3 or less, chlorine dioxide gas d free from the risk of corrosion due to mixing of acidic gas can be generated.

  The chlorine dioxide gas d may explode if the gas phase concentration exceeds 10%. In order to prevent this, the concentration of the chlorine dioxide gas d discharged from the inside upper part of the reaction vessel 10 to the outside is measured by the chlorine dioxide gas concentration meter 54, and the pump is used so that the concentration does not exceed a predetermined upper limit concentration. The operation of the liquid feeding pump 14 and the liquid feeding pump 21 is controlled by the adjusting mechanism 55 to control the supply of the chlorite solution a and the acidic liquid b to the reaction vessel 10. Thereby, the density | concentration of the chlorine dioxide gas d in the reaction container 10 is maintained below a predetermined | prescribed upper limit density | concentration.

  Here, the predetermined upper limit concentration is desirably set to 3% in consideration of safety. Further, as a measure for preventing the upper limit concentration from being exceeded, the pump adjusting mechanism 55 may control the operation of the liquid feeding pump 14 and the liquid feeding pump 21 based on the air volume of air taken into the upper part of the reaction vessel 10 from the outside. it can. That is, when the air volume measured by the air flow meter 52 does not exceed the predetermined air volume, the liquid feeding pump 14 and the liquid feeding pump 21 are not operated, and the electromagnetic valve 15 and the electromagnetic valve 22 are controlled not to be opened. In addition, when the air flow measured by the air flow meter 52 does not exceed a predetermined air flow, control is performed so that the open / close valve 47 provided in the drainage pipe 46 is not always closed. That is, the chlorite solution a and the acidic solution b (mixed solution c) are held inside the reaction vessel 10 only when the air flow exceeds a predetermined air volume so that the generation reaction of the chlorine dioxide gas d proceeds. To do. This ensures that the concentration of chlorine dioxide gas d in the reaction vessel 10 is kept below a predetermined upper limit concentration.

  The recovery tank 45 is installed below the reaction vessel 10, and when the mixed solution c is present in the reaction vessel 10, the mixed solution c in the reaction vessel 10 naturally falls into the recovery tank 45 when the opening / closing valve 47 is opened. It is desirable to move. Moreover, a reaction terminator is put in the recovery tank 45 in advance, and the production reaction of the chlorine dioxide gas d is stopped in the mixed solution c poured into the recovery tank 45. The reaction terminator is an alkaline substance. For example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, etc. are desirable.

  Alternatively, the recovery tank 45 may be provided with a normally closed door, and a reaction stopper containing part may be provided on the upper part thereof. A safe value may be set from the concentration of chlorine dioxide gas harmful to the human body, and when the concentration meter detects that the upper limit has been reached, the open / close door may be opened and a reaction terminator may be introduced into the recovery tank 45.

  Next, FIG. 2 shows a schematic diagram of a disinfection / decontamination system in which the chlorine dioxide gas generator 1 according to the embodiment of the present invention is incorporated and the room 2 is disinfected / decontaminated. The suction side of the suction pipe 50 connected to the reaction vessel 10 of the chlorine dioxide generator 1 and the discharge side of the discharge pipe 51 are connected to the room 2 that is the object of disinfection and decontamination. The room 2 is provided with a blower 60 for stirring the room air and a concentration meter 61 for measuring the concentration of the chlorine dioxide gas d in the room 2. The concentration of the chlorine dioxide gas d in the room 2 measured by the densitometer 61 is input to a pump adjustment mechanism 55 that controls the operation of the liquid feed pump 14 and the liquid feed pump 21. The pump adjustment mechanism 55 controls the operation of the liquid feed pump 14 and the liquid feed pump 21 so that the concentration of the chlorine dioxide gas d in the room 2 becomes a predetermined concentration.

  In the disinfection / decontamination system shown in FIG. 2, the blower 53 is provided in the discharge pipe 51, but the disinfection / decontamination system shown in FIG. 3 is an example in which the blower 53 is installed in the suction pipe 50. Thus, even if the blower 53 is installed in the suction pipe 50, the interior 2 can be similarly disinfected and decontaminated.

In the disinfection / decontamination system shown in FIGS. 2 and 3, for example, the following gas concentration range is assumed and used.
“Concentration of chlorine dioxide gas d discharged from the reaction vessel 10”: 10 vol. Ppm to 3 vol.%
“Concentration of chlorine dioxide gas d in room 2”: 10 vol. Ppm to 10,000 vol. Ppm

  In the operation in the above gas concentration range, the concentration of the chlorite solution a is desirably 10 to 31 wt%. The concentration of the acidic liquid b is desirably in the range of 0.3 to 1.5 in terms of the molar ratio of the acid substance to the chlorite solution a (number of moles of acid substance / number of moles of chlorous acid). If the lower limit of the concentration of the chlorite solution a is lower than this, a large amount of chemical solution is required, and the chlorite solution tank 11, the acid solution tank 12, and the recovery tank 45 are enlarged, This is because the waste liquid treatment cost also increases. The upper limit is the saturation concentration of a solution of sodium chlorite, which is a chlorite generally used for producing chlorine dioxide gas. When the molar ratio is less than 0.3, the generation efficiency of chlorine dioxide gas d from the amount of raw chlorite is low, and when the molar ratio exceeds 1.5, the generation efficiency of chlorine dioxide gas d is further increased. Because it does not.

  Further, in the system shown in FIG. 2, so-called batch-type operation can be performed to disinfect and decontaminate the room 2. In that case, the ventilation operation is performed by first taking in air and exhausting chlorine dioxide gas in an empty state without supplying the chlorite solution a and the acid solution b into the reaction vessel 10. Thereafter, the chlorite solution a and the acidic solution b are supplied into the reaction vessel 10 to generate chlorine dioxide gas d, the chlorine dioxide gas d is introduced into the chamber 2, and the chamber 2 is disinfected and decontaminated. When the densitometer 61 detects a threshold value equal to or lower than a predetermined concentration (intended indoor concentration), the mixed solution c in the reaction vessel 10 is moved to the recovery tank 45 and the generation of chlorine dioxide gas d is stopped. Let Thus, by repeating the ventilation operation and the generation of chlorine dioxide gas d, the room 2 can be disinfected and decontaminated by a so-called batch operation.

  Next, a safe stopping method when a power failure occurs during operation of the gas generator will be described. In addition, although the chlorine dioxide gas generator 1 was demonstrated above, about the matter described below, gas generators other than the chlorine dioxide gas provided with the following conditions, ie, "the acidic chemical | medical solution is used in the reaction container 10. The present invention can be similarly applied to an apparatus that generates a flammable or auxiliary combustible gas by a chemical reaction at a concentration lower than the explosion lower limit concentration or an explosion concentration by self-decomposition.

  The chlorine dioxide gas d described in the above embodiment is an auxiliary combustion gas. If the concentration exceeds 10 vol.%, There is a possibility of explosion due to self-decomposition. As a first method for stopping the reaction that may explode when the concentration becomes high at the time of a power failure, the valve that opens at the time of deenergization is opened automatically at the moment of the power failure. There is a method in which an alkaline reaction terminator is injected into the reaction vessel 10 to neutralize the mixed solution c (acid chemical solution) in the reaction vessel 10 to stop the gas generation reaction. Alternatively, as a second method, a collection tank 45 of the mixed solution c is installed below the reaction vessel 10 as in the chlorine dioxide gas generator 1 previously shown in FIG. There is a way to put a stopper. In this case, the open / close valve 47 provided in the drainage pipe 46 is closed when energized and opened in the event of a power failure, and an alkaline reaction stopper is placed in the recovery tank 45 in advance. Thus, at the moment when a power failure occurs, the open / close valve 47 is opened, and the mixed solution c in the reaction vessel 10 is naturally dropped and moved to the recovery tank 45 to neutralize it, thereby stopping the gas generation reaction.

  However, in any method, while the blower 53 and the like are stopped due to a power failure, a certain amount of time is required until the reaction of the mixed solution c (acid chemical solution) is neutralized by the reaction stopper and the gas generation reaction is stopped. In short, the reaction does not stop instantaneously. However, when the blower 53 or the like is stopped due to a power failure, the blowing mechanism for diluting the gas concentration in the reaction vessel 10 to a predetermined concentration or less is lost, and the gas concentration in the reaction vessel 10 increases. Therefore, in order to prevent the gas concentration in the reaction vessel 10 from increasing, it is necessary to provide an emergency power supply facility, thereby continuing the operation of the blower 53 and the like. Providing emergency power supply equipment increases costs.

  Therefore, in the following, a safety mechanism that avoids an increase in gas concentration and stops the reaction at the time of a power failure without requiring an emergency power supply facility will be described. In addition, the chlorine dioxide gas generator 2 which generates the chlorine dioxide gas d is demonstrated as an example of flammable or auxiliary combustion gas.

  As shown in FIG. 4, in the chlorine dioxide gas generator 2 according to this embodiment as well, as in the chlorine dioxide gas generator 1 described above with reference to FIG. A collection tank 45 for c is installed. A lower end of a drainage pipe 46 connected to the lower surface of the reaction vessel 10 is connected to the recovery tank 45, and an open / close valve 47 is provided in the drainage pipe 46. Moreover, the chlorine dioxide gas generator 2 concerning this embodiment is equipped with the same basic composition as the chlorine dioxide gas generator 1 previously demonstrated in FIG. Therefore, about the common component, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  However, in the chlorine dioxide gas generating apparatus 2 according to this embodiment, the position of the mixed solution c collected in the collection tank 45 and the position above the liquid level of the mixed solution c stored at the bottom of the reaction vessel 10 The connection pipe 70 communicates with the position above the surface. The open / close valve 47 provided in the drainage pipe 46 is closed when energized and is opened during a power failure. As the on-off valve 47, for example, a normally open electromagnetic valve that is opened when no power is supplied can be used. The recovery tank 45 is preliminarily filled with a reaction terminator made of an alkaline substance such as carbonate or bicarbonate. As this reaction terminator, a carbonate or hydrogen carbonate such as sodium carbonate or sodium hydrogen carbonate, which is alkaline in an aqueous solution and generates carbon dioxide gas upon neutralization, is used.

  Also in the chlorine dioxide gas generator 2 according to this embodiment, the chlorite solution a and the acid liquid b are mixed in the reaction vessel 10 as in the chlorine dioxide gas generator 1 described above with reference to FIG. , Chlorine dioxide gas (ClO2) d is generated by the chemical reaction between the two. Moreover, temperature control by the temperature control mechanism 35 and stirring by the stirrer 30 are appropriately performed, and the reaction of the mixed solution c is promoted.

  Then, in a state where chlorine dioxide gas d is stored inside the reaction vessel 10, external air is taken into the upper part of the reaction vessel 10 through the suction pipe 50 by the operation of the blower 53, and the upper inside of the reaction vessel 10. Atmosphere (chlorine dioxide gas d) is discharged to the outside through the discharge pipe 51.

  On the other hand, when a power failure occurs during operation of the chlorine dioxide gas generator 2 according to this embodiment, the operation of the blower 53 is stopped due to the power failure, the intake of outside air into the reaction vessel 10 and the outside from the reaction vessel 10 to the outside. The discharge of the chlorine dioxide gas d is stopped. Further, the operation of the liquid feeding pump 14 and the operation of the liquid feeding pump 21 are stopped, and the supply of the chlorite solution a and the supply of the acidic liquid b are also stopped.

  At the same time, the open / close valve 47 formed of a normally open electromagnetic valve or the like is opened simultaneously with a power failure, and the mixed solution c in the reaction vessel 10 moves to the recovery tank 45 by natural fall through the drain pipe 46. Thus, in the recovery tank 45, the mixed solution c is neutralized by the reaction terminator made of an alkaline substance of carbonate or hydrogen carbonate previously placed in the recovery tank 45, and the generation reaction of the chlorine dioxide gas d is stopped. In the recovery tank 45, carbon dioxide gas is generated at the same time as the mixed chemical c is neutralized.

  The carbon dioxide gas thus generated in the recovery tank 45 flows into the reaction vessel 10 through the connection pipe 70 and dilutes the chlorine dioxide gas d in the reaction vessel 10 while remaining in the reaction vessel 10 through the suction pipe 50. Gas is discharged to the outside. As a result, the inside of the reaction vessel 10 is diluted with carbon dioxide gas, and an explosion due to an increase in concentration is avoided.

  Therefore, according to the chlorine dioxide gas generator 2 according to this embodiment, the gas concentration in the reaction vessel 10 at the time of a power failure can be diluted without a blower mechanism by an emergency power source that increases costs. Thereby, the apparatus can be safely shifted to a stopped state without blowing by an emergency power source. Therefore, an emergency power supply facility that has been necessary in the past is not necessary, and the cost can be reduced.

  In addition, although the apparatus which generate | occur | produces chlorine dioxide gas was demonstrated, the chlorine dioxide gas generation apparatus 2 concerning this embodiment is not restricted to the chlorine dioxide gas d, The apparatus (other than the flammability or auxiliary combustion gas) ( It can also be applied to flammable or auxiliary gas generators. A device that sends an acidic chemical solution to the reaction vessel 10 and automatically and continuously generates a flammable or combustible gas by a chemical reaction with other chemicals in the reaction vessel 10 (flammable or combustible gas generating device). In addition to chlorine dioxide gas, for example, the following can be considered.

A gas generator that supplies hydrogen sulfide gas H ₂ S by supplying acidic chemicals to metal sulfides. Hydrogen sulfide gas is flammable, and the lower limit of explosion is about 4.3%. A gas generator that generates hydrogen gas H ₂ by supplying acidic chemicals to metals (Fe, Zn, Mg). Hydrogen gas is flammable, and the lower explosion limit is about 4%.

  The diameter of the connecting pipe 70 provided in the chlorine dioxide gas generator 2 according to this embodiment is such that when the volume corresponding to the volume of the reaction vessel 10 is passed in 1 minute, the surface wind speed is from 1 m / s to 20 m / s. The aperture is preferably in the range of s. Moreover, the reaction terminator put in the recovery tank 45 in advance is alkaline or carbonate such as sodium carbonate or sodium hydrogen carbonate, and produces a carbon dioxide gas or bicarbonate when neutralizing.

An example of disinfection / decontamination of the room 2 using the disinfection / decontamination system shown in FIG. 2 will be described. The reaction vessel 10 has a diameter of 700 mmφ × height 900 mm, and 150
A suction pipe 50 and a discharge pipe 51 of mmφ were connected to the room 2 having a volume of 1000 m3 which is the object of disinfection and decontamination. Room 2 was previously adjusted to a humidity of 60%. Chlorine dioxide gas d is supplied to the room 2 and the target gas concentration in the room 2 is set to 400.
The operation was carried out so that the average concentration of chlorine dioxide gas d in the room 2 during the period from the start to 3 hours exceeded 380 ppm. The chlorite solution a contains 25
A wt% sodium chlorite solution was used, and a 30 wt% malic acid solution was used for the acidic solution b. The chlorite solution a and the acid solution b were respectively added to the reaction vessel 10 while the air flow was kept constant at a flow rate of 190 m3 / h.
L / min was supplied, and ON / OFF control was performed according to the gas concentration in the room 2. The temperature of the mixed solution c in the reaction vessel 10 was about 25 ° C. Further, a blower 60 for stirring the indoor air was installed in the room 2, and air was blown and stirred so that the gas concentration in the room 2 was uniform. FIG. 4 shows the change over time in the gas concentration in the room 2 at this time. From FIG. 4, the average concentration of the indoor gas from the start to 3 hours was 390 ppm, which was the intended indoor concentration. The maximum value of the outlet gas concentration in the reaction vessel 10 was 0.8%, which was less than 3% of the design upper limit, and the total amount of the chemical solution was 65 L. Furthermore, the time-dependent change of indoor humidity at this time is shown in FIG. It can be seen that the room humidity hardly increased and was kept almost constant.

Similar to the first embodiment, another example in which the room 2 is disinfected / decontaminated by the disinfection / decontamination system shown in FIG. 3 will be described. The reaction vessel 10 has a diameter of 700 mmφ × height 900 mm, and 150
A suction pipe 50 and a discharge pipe 51 of mmφ were connected to the room 2 having a capacity of 1000 m3 and being subjected to disinfection / decontamination. Room 2 was previously adjusted to a humidity of 60%. Chlorine dioxide gas d is supplied to the room 2 and the target gas concentration in the room 2 is set to 400.
The operation was carried out so that the average concentration of chlorine dioxide gas d in the room 2 during the period from the start to 3 hours exceeded 380 ppm. The chlorite solution a contains 25
A wt% sodium chlorite solution was used, and a 9 wt% sulfuric acid solution was used for the acidic solution b. The chlorite solution a and the acid solution b were respectively added to the reaction vessel 10 while the air flow was kept constant at a flow rate of 190 m3 / h.
L / min was supplied, and ON / OFF control was performed according to the gas concentration in the room 2. The temperature of the mixed solution c in the reaction vessel 10 was about 40 ° C. Further, a blower 60 for stirring the indoor air was installed in the room 2, and air was blown and stirred so that the gas concentration in the room 2 was uniform. FIG. 6 shows the change over time in the gas concentration in the room 2 at this time. From FIG. 6, the average indoor gas concentration from the start to 3 hours was 390 ppm, which was the intended indoor concentration. The maximum value of the outlet gas concentration in the reaction vessel 10 was 1.1%, which was less than 3% of the design upper limit, and the total amount of chemical solution was 37 L. Furthermore, the time-dependent change of the indoor humidity at this time is shown in FIG. It can be seen that the room humidity hardly increased and was kept almost constant.

An embodiment of the present invention in the chlorine dioxide gas generator 2 shown in FIG. 4 will be described. In Example 3, 50 L of 9 wt% sulfuric acid was used as the acid chemical solution, and 50 L of 25 wt% sodium chlorite aqueous solution was used as the substance that reacts with the acid to generate chlorine dioxide gas. In addition, a sodium hydrogen carbonate powder in an amount capable of neutralizing the total amount of the acid chemical solution was placed in a 200 L recovery tank in advance. The reaction vessel has a diameter of 700 mmφ x height of 900 mm and a volume of 350
L. The connecting pipe was a PVC pipe having an inner diameter of 30 mm. The above chemicals were added to each of the reaction vessels while the air flow was kept constant at a flow rate of 190 m ³ / h.
Supplied at L / min. The chlorine dioxide gas concentration in the reaction vessel was continuously measured with a densitometer. While supplying the chemical solution with the liquid feed pump, when each 49 L, which is almost the total amount of the chemical solution, was supplied, a power failure was simulated and the entire power supply was cut off to confirm the operation. As the mixed solution (chemical solution) moved from the reaction vessel to the recovery tank, CO ₂ gas was generated in the recovery tank by a neutralization reaction. CO ₂ gas was transferred from the recovery tank to the reaction vessel through a connecting pipe. It took 2 minutes for the chemical to completely transfer from the reaction vessel to the recovery tank. During this time, it was confirmed that the chlorine dioxide gas concentration in the reaction vessel was always less than 10 vol.%.

  The present invention relates to an apparatus or a room to be sterilized, a deodorized treatment area such as a duct or a draft chamber closed in a certain section, a surface inside the space, sterilization of microorganisms, sterilization, a clean room, a hospital, a hotel room, etc. It is useful for deodorization of a desired area such as sterilization and sterilization of microorganisms.

a Chlorite solution b Acidic liquid c Mixed solution d Chlorine dioxide gas 1 Chlorine dioxide gas generator 2 Indoor 10 Reaction vessel 11 Chlorite solution tank 12 Acid liquid tank 13 Chlorite solution supply pipe 14 Liquid feed pump 15 Electromagnetic valve 20 Acidic liquid supply pipe 21 Liquid feed pump 22 Electromagnetic valve 25 Small container 30 Stirrer 31 Thermometer 35 Temperature control mechanism 36 Heat transfer pipe 37 Heat exchanger 38 Pump 39 Heat source circuit 40 Pump 41 Pump adjustment mechanism 42 Cooling / heating source 45 Recovery tank 46 Drainage pipe 47 Opening / closing valve 50 Suction pipe 51 Discharge pipe 52 Air flow meter 53 Blower 54 Chlorine dioxide gas concentration meter 55 Pump adjustment mechanism 56 Holding body 60 Blower 61 Concentration meter 70 Connecting pipe

Claims (9)

A chlorine dioxide gas generator that supplies a chlorite solution and an acidic liquid to a sealed reaction vessel and generates chlorine dioxide gas by a chemical reaction between the two,
A suction pipe for taking air into the reaction vessel, which is opened above the liquid level of the mixed solution of the chlorite solution and the acidic solution stored at the bottom of the reaction vessel, and the bottom of the reaction vessel. A discharge pipe that opens above the liquid level of the mixed solution of the chlorite solution and the acidic liquid and discharges chlorine dioxide gas generated in the reaction vessel to the outside is provided , and external air is passed through the suction pipe. A chlorine dioxide gas generator, wherein the chlorine dioxide gas generator is taken into the upper part of the reaction vessel and discharges the atmosphere inside the reaction vessel to the outside through the discharge pipe . Inside the reaction container, there is a small container disposed above the liquid level of the mixed solution of chlorite solution and acidic liquid,
The chlorite solution and the acid solution supplied to the reaction vessel are first supplied to the small vessel and mixed, and then overflow and are stored at the bottom of the reaction vessel. The chlorine dioxide gas generator as described.   The chlorine dioxide gas generator according to claim 1 or 2, further comprising a pump adjusting mechanism for controlling the supply of the chlorite solution and the acid solution.   A blower is provided in the suction pipe or the discharge pipe,
  The external air is taken into the upper part of the reaction container through the suction pipe by the operation of the blower, and the atmosphere in the upper part of the reaction container is discharged to the outside through the discharge pipe. The chlorine dioxide gas generator according to any one of the above.   The alkaline substance of any one of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium hydrogen carbonate is used as a reaction stopper for chlorine dioxide gas generation reaction. Chlorine dioxide gas generator. A mixed solution recovery tank is installed below the reaction vessel, and a lower end of a drainage pipe connected to the lower surface of the reaction vessel is connected to the recovery tank. An open / close valve that is closed and opened at the time of a power failure is provided, and a reaction stopper made of an alkaline substance of carbonate or bicarbonate is put in the recovery tank,
Above the liquid level of the mixed solution stored at the bottom of the reaction vessel and above the liquid level of the mixed solution collected in the recovery tank are communicated by a connecting pipe, The chlorine dioxide gas generator according to any one of claims 1 to 5.   The chlorine dioxide gas generator according to claim 6, wherein the open / close valve that is closed when energized and opened during a power failure is a normally open electromagnetic valve.   The diameter of the connecting pipe is such that the surface wind speed is in the range of 1 m / s to 20 m / s when the volume corresponding to the volume of the reaction vessel is passed in 1 minute. The chlorine dioxide gas generator described in 1.   A chlorine dioxide gas generation method of supplying a chlorite solution and an acidic liquid to a sealed reaction vessel and generating chlorine dioxide gas by a chemical reaction between the two,
  External air is taken into the upper part of the reaction vessel through a suction pipe opened above the liquid level of the mixed solution of the chlorite solution and the acidic solution stored at the bottom of the reaction vessel. Chlorine dioxide, characterized in that the atmosphere above the inside of the reaction vessel is discharged to the outside through a discharge pipe opened above the liquid level of the mixed solution of the chlorite solution and the acid solution stored at the bottom. Gas generation method.

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