JP6637133B1 - Industrial washing machine sterilization method, sterilizing apparatus, and industrial washing machine using industrial washing machine sterilization method - Google Patents

Abstract

An object of the present invention is to provide a method for sterilizing an object to be washed in a commercial washing machine, which can surely sterilize microorganisms including Bacillus cereus using chlorine dioxide when washing the object to be washed. Provided is a commercial washing machine using a method of sterilizing an object to be washed of a washing machine for business use. The present invention relates to a method for disinfecting an object to be washed, which is used in a washing machine 2 for washing an object to be washed 1 and sterilizes the object to be washed 1 in a washing tub 3 of the washing machine 2. A chlorine dioxide generating step 4 of mixing water and a plurality of chemicals A, B, and C to generate a high concentration of chlorine dioxide; and a washing tub of the high concentration chlorine dioxide generated in the chlorine dioxide generating step 4. And an injection diluting step 5 for diluting the article to be washed 1 in the washing tub 3 and diluting it to a predetermined concentration with washing water. [Selection diagram] Fig. 1

Description

  The present invention relates to a method of disinfecting a washing machine for use in a commercial washing machine, a disinfecting apparatus, and a disinfecting method for a washing machine used in a commercial washing machine, which is used when washing and sterilizing designated laundry consigned by a hospital or a nursing facility. To a commercial washing machine using the method.

  Laundry (underwear, towels, sheets, etc.) commissioned by hospitals, nursing homes, etc., is so-called designated laundry (to-be-washed) and is consigned to a laundry trader operating under the Cleaning Business Law to be washed and sterilized. In addition, general bacteria and Bacillus cereus attached to the laundry are sterilized. The method of washing designated laundry is defined by the Cleaning Business Law, and the washing method stipulates that the designated laundry is disinfected and sterilized.

  Disinfection and sterilization methods defined by the Cleaning Business Law include physical methods and chemical methods. As the physical methods, "disinfection and sterilization by steam" and "disinfection and sterilization by boiling water" are defined. As the chemical methods, “disinfection and sterilization with a chlorine agent”, “disinfection and sterilization with a surfactant”, “disinfection and sterilization with chlorhexidine”, and “disinfection and sterilization with gas” are defined.

  As disinfection and sterilization by chemical methods, for example, sterilization with a chlorinating agent is performed by exposing the designated laundry after washing to flour, sodium hypochlorite, etc., in an aqueous solution containing 250 ppm or more of free chlorine at 30 ° C. or more for 5 minutes. The above is performed by immersion.

  Patent Document 1 discloses a sterilizing method and a sterilizing apparatus using hypochlorous acid. In this Patent Document 1, a pre-washing tub, a washing tub, a rinsing tub, and a finishing tub are provided continuously, and in each tub, designated laundry is pre-washed, washed, rinsed, and then washed in the finishing tub. Finished. The designated laundry is disinfected and sterilized by a chlorinating agent such as sodium hypochlorite, which is set at a predetermined concentration and injected into the disinfecting tub according to the method defined in the Cleaning Business Law. I have.

  However, in 2006, at a hospital attached to Jichi Medical University in Tochigi Prefecture, an in-hospital infection of bacteremia that appeared to be caused by linens such as sheets during infusion occurred, two of which developed sepsis and died. The other blinded one eye. Later it turned out that the washing machine in the cleaning factory was contaminated. In a hospital in Shizuoka Prefecture in 2007, a case of hospital infection suspected of linen contamination, such as neonatal sepsis caused by linens such as sheets or diapers and towels as the source of infection (quoted wikipedia) was reported. Have been. At the National Cancer Center Hospital (Chuo, Tokyo), 13 hospitalized patients were infected with B. cereus, two of whom died. In order to wipe the patient's body, Bacillus cereus was found in unused towels supplied by a vendor in Tokyo, and there have been reports of infections that may have infected the towels. Therefore, measures to prevent infection with Bacillus cereus are required.

JP 2009-119089 A

  However, in the sterilization treatment by "disinfection and sterilization by boiling water", "sterilization and sterilization by chlorine agent", "sterilization and sterilization by surfactant", "sterilization and sterilization by chlorhexidine", and "sterilization and sterilization by gas" Although it can kill bacteria, it is not a perfect means of killing spore-forming bacteria, including Bacillus cereus.

  On the other hand, chlorine dioxide, one of the chlorine agents, is an effective disinfectant against spores such as Bacillus cereus, as well as bleaching of paper pulp, disinfection of food, disinfection of tap water, disinfection in safety cabinets. Its high bactericidal effect is also recognized in official documents such as the Japanese Pharmacopoeia 16th Edition, the United States Environmental Protection Agency, and the Food and Drug Administration.

However, since chlorine dioxide is an unstable substance, it is difficult to transport and store it for a long period of time, and it is considered that chlorine dioxide is required to be generated at the place of use at the time of use. According to the U.S. Environmental Protection Agency's report on the disinfection method of tap water, which is more advanced in Japan than in Japan in the chlorine dioxide industry, the following method is mainly used for its generation.
2NaClO ₂ + Cl ₂ (g) → 2ClO ₂ (g) + 2NaCl
2NaClO ₂ + HOCl → 2ClO ₂ (g) + NaCl + NaOH
5NaClO ₂ + 4HCl → 4ClO ₂ + 5NaCl + 2H ₂ O

  The chemicals used in these methods are all chemicals that require careful handling such as chlorine gas and hydrochloric acid.For example, in operation in water treatment of tap water, a liquid tank of sodium chlorite, chlorine gas, A reaction tank, a chlorine dioxide solution storage tank is provided, sodium chlorite is supplied to the reaction tank, chlorine gas is blown there to generate chlorine dioxide, and the generated chlorine dioxide is transferred to a chlorine dioxide liquid tank, While controlling the concentration by diluting it with water to a concentration that is easy to handle, supply the chlorine dioxide solution to the raw water and sterilize as needed. In such equipment, safety management costs are inevitably high in terms of mechanical aspects, and the pH is too low or a large amount of chlorine dioxide gas is generated. Was not.

  Further, in a continuous or batch type washing machine widely used as a commercial washing machine, processes such as prewashing, main washing, rinsing, and finishing are subdivided in each washing machine. The processing time in each process is only a very short time of about one and a half to six minutes. On the other hand, the amount of retained water is about 200 to 600 L. Therefore, when a chlorine dioxide solution of about 1000 ppm, which is relatively easy to handle, is used for sterilization. In order to fill the required 20-50 ppm chlorine dioxide solution with water in the tank, 4 liters to 30 liters of chlorine dioxide solution must be sent into the tank depending on the amount and concentration of water. Since it exceeds 200 times, the storage volume of the chlorine dioxide solution is required to be at least 800 L, and the initial cost of such a volume of the chlorine dioxide solution tank must be extremely high when the equipment is introduced. For a chlorine dioxide solution whose concentration is difficult to control during long-term storage, it is not possible to provide a chlorine dioxide solution tank of a certain concentration in advance and to send a certain amount of the solution at an appropriate timing. Accordingly, in order to use chlorine dioxide in a commercial washing machine, the chlorine dioxide solution is generated and sent to the commercial washing machine in a short time of about one and a half to six minutes, which is the processing time for one layer. If the exposure time required for sterilization is subtracted, it is necessary to consider that the time taken from the generation of the chlorine dioxide solution to the sending of the solution is a maximum of about 3 minutes. Therefore, in the method of generating a low-concentration chlorine dioxide solution, the required amount of liquid supply increases, especially in a general continuous washing machine in which the cycle time is short and the amount of water in the tub is 300 L or more, stable liquid supply is required. On the other hand, in the method of generating a high concentration of chlorine dioxide solution, a large amount of chlorine dioxide gas is generated, which increases the danger and, depending on the selection of the reactants, has a problem that the pH becomes too low. There was no way to match the conditions.

  Therefore, the present invention provides a method for sterilizing a washing machine, a sterilizing apparatus, and a business machine for a washing machine for business, which can surely sterilize microorganisms including Bacillus cereus using chlorine dioxide when washing the washing object. An object of the present invention is to provide a washing machine for business use using a method of sterilizing an object to be washed of a washing machine.

  One embodiment of the present invention for solving the above-mentioned problem is used in a washing machine for washing an object to be washed, and a washing object for a washing machine for sterilizing the object to be washed in a washing tub of the washing machine. A sterilization method, a chlorine dioxide generation step of mixing water and a plurality of chemicals to generate a high concentration of chlorine dioxide, and a high concentration of chlorine dioxide generated in the chlorine dioxide generation step in the washing tub. An injection dilution step of injecting and diluting the object to be washed into the washing tub to a predetermined concentration with washing water.

  In one embodiment of the present invention, in the chlorine dioxide generating step, water is supplied to the mixing reaction tank in advance, and then the plurality of chemicals are injected into the reaction tank in a predetermined order, and the plurality of chemicals are injected into the reaction tank. A mixture of high-concentration chlorine dioxide and water generated by the plurality of injected chemicals is injected into the washing tub.

Further, one embodiment of the present invention is characterized in that the concentration range of the chlorine dioxide diluted with the washing water in the washing tub is in a range of 10 ppm to 100 ppm, and the chlorine dioxide is brought into contact with an object to be washed for 90 seconds or more. And

  One embodiment of the present invention is characterized in that a mixed solution of water and a plurality of chemicals generated in the chlorine dioxide generation step has a hydrogen ion index of 5 to 7.

  One embodiment of the present invention is characterized in that the plurality of drugs are a chlorite solution, a hypochlorite solution, and an acid solution.

  In one embodiment of the present invention, the chlorite solution is a sodium chlorite solution, the hypochlorite solution is a sodium hypochlorite solution, and the acid solution is a citric acid solution. Features.

  In one embodiment of the present invention, sodium chlorite is 0.002 to 0.02%, sodium hypochlorite is 0.001 to 0.01%, and The acid is characterized by being injected at 0.001 to 0.03%.

  One embodiment of the present invention is a sterilization apparatus used in a washing machine for washing an object to be washed, which sterilizes the object to be washed in a washing tub of the washing machine, wherein water and a plurality of chemicals are mixed. A chlorine dioxide generating unit that generates high-concentration chlorine dioxide, and an injection diluting unit that injects the high-concentration chlorine dioxide generated by the chlorine dioxide generating unit into the washing tub and dilutes the same to a predetermined concentration. It is characterized by the following.

  In one aspect of the present invention, the chlorine dioxide generating section includes a plurality of drug storage tanks each storing a plurality of drugs, a reaction tank in which the plurality of drugs are injected and react to generate chlorine dioxide, And a plurality of medicine injection pumps for injecting a predetermined amount of medicine in the plurality of medicine storage tanks into the reaction tank in a predetermined order.

Another embodiment of the present invention, a washing machine for washing the washing object, the claim chlorine dioxide generation definitive to be washed product sterilization method of industrial washing machine according to any one of claims 1 to 7 The mixed solution containing high-concentration chlorine dioxide generated in the process is poured into the washing tub, and the washing is performed in a state where the mixed solution is diluted to a predetermined concentration with the washing water stored in the washing tub. It is characterized by sterilizing things while washing them.

  ADVANTAGE OF THE INVENTION According to this invention, when wash | cleaning a to-be-washed thing, the microorganisms containing Bacillus cereus can be reliably sterilized by washing using the washing water containing chlorine dioxide. In addition, since a solution containing chlorine dioxide having a predetermined concentration by diluting high-concentration chlorine dioxide with washing water is used as washing water, a sterilizing tank or a disinfecting tank for sterilizing the object to be washed separately from the washing tank. There is no need to provide

  Further, according to the present invention, since high-concentration chlorine dioxide is generated and then injected into a washing tub of a washing machine and diluted, a high-concentration chlorine dioxide storage tank becomes unnecessary, and chlorine dioxide solution and gas from the storage tank are eliminated. Leakage and the like do not physically occur and handling is safe and easy.

FIG. 1 is a process diagram showing the steps of a method of sterilizing an object to be washed in a commercial washing machine according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing a sterilizing apparatus and a commercial washing machine using the method for sterilizing an object to be washed of the commercial washing machine according to the embodiment of the present invention. FIG. 3 is a chart showing the presence or absence of general bacteria and Bacillus cereus in a washing object sterilized by the washing object sterilization method for a commercial washing machine according to the embodiment of the present invention. FIG. 4 is a schematic configuration diagram showing a sterilizing apparatus using a method of sterilizing an object to be washed in a commercial washing machine and a continuous commercial washing machine. FIG. 5 is a schematic configuration diagram showing another sterilization apparatus.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for sterilizing an object to be washed of a commercial washing machine according to an embodiment of the present invention (hereinafter, referred to as a “sterilizing method”), a sterilizing apparatus, and a commercial washing machine using the method of sterilizing an object to be washed of a commercial washing machine Will be described with reference to the drawings.

[Method of disinfecting laundry for commercial washing machine]
The method for sterilizing an object to be washed of a commercial washing machine according to an embodiment of the present invention is used in a washing machine 2 for washing an object to be washed 1 and sterilizes the object to be washed 1 in a washing tub 3 of the washing machine 2. To process. As shown in FIG. 1, the sterilization method according to the embodiment of the present invention includes a chlorine dioxide generation step 4 of mixing water and a plurality of drugs A, B, and C to generate a high concentration of chlorine dioxide. A high-concentration chlorine dioxide generated in the chlorine generation step 4 is injected into the washing tub 3, and the washing and washing of the article 1 in the washing tub 3 is diluted to a predetermined concentration by washing water 5. .

  In the chlorine dioxide generation step 4, a plurality of drugs A, B, and C are injected into the reaction tank 10 in a predetermined order, water is supplied, and the plurality of drugs A, B, and C injected into the reaction tank 10 are mixed with water. Is injected into the washing tub 3 in the injection dilution step 5. The range of the concentration of chlorine dioxide diluted with the washing water in the washing tub 3 is set to be 20 ppm to 50 ppm. In addition, the hydrogen ion exponent [pH] of the mixture of water and the plurality of drugs A, B, and C generated in the chlorine dioxide generation step 4 is set to 5 to 7.

  The plurality of medicines A, B, and C in the method for sterilizing articles to be washed according to the present embodiment are a chlorite solution A, a hypochlorite solution B, and an acid solution C. The acid salt solution A is a sodium chlorite solution, the hypochlorite solution B is a sodium hypochlorite solution, and the acid solution C is a citric acid solution. Further, the concentration of sodium chlorite in the sodium chlorite solution used in the sterilization method according to the present embodiment is 25%, the concentration of sodium hypochlorite in the sodium hypochlorite solution is 12%, The concentration of citric acid in the acid solution is between 10% and 30%.

Then, with respect to the amount of water in the washing tub 3, a mixture of a sodium chlorite solution as the medicine A, a sodium hypochlorite solution as the medicine B, and a citric acid solution as the medicine C is 0.02 to 0.05. %, The concentration of chlorine dioxide assumed in the washing tub 3 is set to a concentration of 20 to 50 ppm. For example, if the amount of the washing water in the washing tub 3 is 400 L, the washing water is reacted with 80 to 200 g of each aqueous solution of sodium chlorite, sodium hypochlorite, and citric acid.
Next, a sterilizing apparatus using the method for sterilizing an object to be washed of a commercial washing machine according to the present embodiment will be described.

[Sterilizer]
As shown in FIG. 2, the sterilizing apparatus 6 according to the present embodiment includes a chlorine dioxide generator 7 that mixes a plurality of drugs A, B, and C to generate a high concentration of chlorine dioxide, and a chlorine dioxide generator 7. And an injection diluting unit 8 for injecting the high-concentration chlorine dioxide generated in the above into the washing tub 3 and diluting it to a predetermined concentration.

  The chlorine dioxide generating unit 7 is configured to store a plurality of medicines A, B, and C, respectively, a plurality of medicine storage tanks 9 (9a, 9b, 9c), and the plurality of medicines A, B, C, and water are injected and reacted. A reaction tank 10 for producing high-concentration chlorine dioxide, a plurality of medicine injection pumps 11 (11a, 11b, 11c) for injecting a predetermined amount of medicine in the plurality of medicine storage tanks 9 into the reaction tank 10, respectively. It is formed with.

  Each chemical storage tank 9 is connected to the inlet 13 (13b, 13c, 13d) of the reaction tank 10 by a pipe 12 (12a, 12b, 12c). Each of the drug injection pumps 11 (11a, 11b, 11c) is provided in the middle of each of the pipes 12a, 12b, 12c. Further, water is supplied into the reaction tank 10 through a pipe 14 communicating with the injection port 13a. A valve 15 is provided in the middle of the pipe 14.

  The injection port 13b of the reaction tank 10 and the drug storage tank 9a are connected by a pipe 12a, the injection port 13c and the drug storage tank 9b are connected by a pipe 12b, and the injection port 13d and the drug storage tank 9c are connected by a pipe 12c. Have been. Then, the medicine A is injected into the reaction tank 10 from the medicine reservoir 9a by the medicine pump 11a through the injection port 13b, and the medicine B is injected from the medicine storage tank 9b through the injection port 13c by the medicine pump 11b. The medicine C is injected into the reaction tank 10 through the injection port 13d from the medicine storage tank 9c by the medicine pump 11c. Water is supplied by a pipe 14 and injected into the reaction tank 10 through an injection port 13a. In the reaction tank 10, water and the chemicals A, B, and C are mixed by a predetermined mixing procedure to generate a mixed liquid containing high-concentration chlorine dioxide. Sent to 8 for dilution.

  The injection diluting section 8 includes a washing tub 3 of the washing machine 2, a pipe 16 that connects the washing tub 3 and the reaction tank 10, and an injection pump 17 provided in the middle of the pipe 16. In the washing tub 3, an object 1 to be washed and washing water (rinsing water) for washing (rinsing) the object 1 are stored in advance. A mixed solution containing high-concentration chlorine dioxide generated in the reaction tank 10 is injected into the washing tub 3 by an injection pump 17, and the high-concentration chlorine dioxide is diluted with washing water. In the present embodiment, the concentration of chlorine dioxide in washing tub 3 is set at 20 to 50 ppm. The addition rate of each of the medicines A, B, and C is about 0.04% of the amount of water in the washing tub 3. For example, if the amount of water in the washing tub 3 is 200 L, each of the medicines A, B, and C is 80 g. is there. Therefore, chlorine dioxide generated by mixing 80 g × 3 = 240 g is diluted with 200 L of water, and the dilution ratio becomes 830 times.

  Before dilution with the washing water in the washing tub 3, the concentration of chlorine dioxide is inevitably extremely high at 20,000 ppm, and therefore, there is a danger in handling. At present, water is added before adding each of the drugs A, B, and C. It has been diluted in advance. That is, water is previously diluted into the reaction tank 10 by injecting water from the injection port 13 a through the pipe 14. If the concentration of chlorine dioxide is about 4000 to 10000 ppm, it is easy to handle, so if about 1 L of water is put in the reaction tank 10, it is diluted about 4 times and the concentration becomes about 5000 ppm, making it easy to handle. Become.

The basic procedure for producing chlorine dioxide by the sterilizer in the present embodiment is as follows:
1: Mixing of chlorous acid (drug A) and hypochlorous acid (drug B) 2: Addition of acidic water (drug C + water) 3: Generation of chlorine dioxide
1: Chlorous acid (drug A) + acidic water (drug C + water) → chlorine dioxide is generated 2: Hypochlorous acid (drug B) + acid water (drug C + water) → chlorine is generated 3: Chlorine Acid (Drug A) + Chlorine → Chlorine Dioxide Produced It is preferable to add water before the production procedure 1 to increase the safety in handling.

  In addition, in the adjustment of the hydrogen ion index (pH) of the chlorine dioxide to be generated, chlorine dioxide is not generated in a mixed state in which chlorous acid (drug A) and hypochlorous acid (drug B) are alkaline at first. Therefore, chlorine water is taken out by mixing acidic water (drug C + water) and lowering the pH value.

  In the final washing step (rinsing step), the pH of the washing water in the washing tub 3 is preferably closer to neutral, and the alkaline washing water in the washing step is neutralized by adding an acid in the rinsing step. adjust. For the production of chlorine dioxide only, there is a method of increasing the yield by adding, for example, a large amount of hydrochloric acid to chlorous acid (drug A), but in this case, the pH value is too low, which is not desirable. Therefore, by generating chlorine dioxide by the above-described production procedure, chlorine dioxide is generated in a high yield without extremely lowering the pH value.

Next, a mixing procedure for injecting and mixing the medicine A, the medicine B, the medicine C, and water into the reaction tank 10 will be described. There are the following four mixing procedures for mixing the medicine A, the medicine B, the medicine C, and water. In the present embodiment, the procedure 1 produces a high concentration of chlorine dioxide. It should be noted that a high concentration of chlorine dioxide may be generated by the procedures 2, 3, and 4.
As described above, the medicine A, the medicine B, and the medicine C are:
Drug A: Sodium chlorite Drug B: Sodium hypochlorite Drug C: Citric acid Procedure 1
Stage 1 Drug A + Drug B
Stage 2 [Drug A + Drug B] + Drug C
Third Step [Drug A + Drug B] + Drug C + Water In Procedure 1, in the first step, drug A and drug B are injected into reaction vessel 10 through injection ports 13b and 13c, and in the second step, C is injected into the reaction tank 10 from the injection port 13d. In the third stage, water is injected into the reaction tank 10 through the injection port 13a to generate a high concentration of chlorine dioxide.

The following shows another mixing procedure for drugs A, B, and C.
Step 2
Stage 1 Drug A + Drug C
Stage 2 [Drug A + Drug C] + Drug B
Third step [drug A + drug C] + drug B + water In the procedure 2, in the first step, the drug A and the drug C are injected into the reaction tank 10 through the injection ports 13b and 13d, and in the second step, the drug B is injected into the reaction tank 10 from the injection port 13c. In the third stage, water is injected into the reaction tank 10 from the injection port 13a to generate a high concentration of chlorine dioxide.

Step 3
1st step Drug A + Drug B + Drug C + Water 2nd step [Drug A + Drug B + Drug C + Water] + Water In procedure 3, in the first step, Drug A, Drug B and Drug C are injected 13b, 13c, and 13d are injected into the reaction tank 10, and water is injected into the reaction tank 10 from the injection port 13a. In the second stage, water is further injected into the reaction tank 10 from the injection port 13a to generate a high concentration of chlorine dioxide.

Step 4
1st stage Drug A + Drug B or Drug A + Drug C + Water-> Send to washing tub 3 Second stage Drug B + Water or Drug C + Water-Send to washing tub 3 In Procedure 4, in the first stage The medicine A is injected into the reaction tank 10 from the injection port 13b, the medicine B or the medicine A is injected into the reaction tank 10 from the injection port 13c or the injection port 13b, and the medicine C is injected into the reaction tank 10 from the injection port 13d. inject. At the same time, water is injected into the reaction tank 10 from the injection port 13a to generate a mixed solution, and the mixed solution is sent into the washing tub 3. In the second stage, the medicine B is injected into the reaction tank 10 from the injection port 13c, and water or the medicine C is injected into the reaction tank 10 from the injection port 13a or the injection port 13d. At the same time, water is injected into the reaction tank 10 from the injection port 13a to form a mixed solution, and the mixed solution is injected (liquid sending) into the washing tub 3.

  The mixing procedure 3 requires the reaction tank 10 and requires a large amount of liquid. The mixing procedures 1 and 2 are substantially the same procedure. The mixing procedure 2 is slightly better in terms of reaction efficiency. The mixing procedure 4 is a method of mixing inside the washing tub 3 and has a high degree of safety in handling chlorine dioxide. In the mixing procedure 4, if the time lag between the first stage and the second stage is reduced and the amount of water used for liquid feeding is small, the reaction efficiency is not bad. The greatest advantage is that in the mixing procedures 1, 2, and 3, a solution containing a high concentration of chlorine dioxide may touch the article 1 for a short time. In the present embodiment, a mixed solution containing a high concentration of chlorine dioxide is generated in the reaction tank 10 by the mixing procedure 1, and the mixed liquid is diluted by injecting (liquid sending) into the washing tank 3.

  Next, the effect of sterilization by the mixed solution containing chlorine dioxide diluted in the washing tub 3 and the effect on the article to be washed will be described. As shown in FIG. 3, when the concentration of chlorine dioxide in the washing water diluted with the washing water in the washing tub 3 is 25 ppm, some general bacteria remain and some Bacillus cereus remain. When the concentration of chlorine dioxide is 30 ppm or more, general bacteria and Bacillus cereus are not detected and all are sterilized. In addition, when the concentration of chlorine dioxide was 55 ppm, damage to the washing object occurred. Therefore, by setting the concentration of chlorine dioxide in the washing water in the washing tub 3 to 20 to 50 ppm, the microorganisms including Bacillus cereus can be reliably sterilized without damaging the article 1 to be washed.

  Next, the sterilizing effect of the chlorine dioxide solution will be described. The bactericidal effect test was performed at the Japan Food Research Laboratories. In the test method, a chlorine dioxide solution having a concentration of 10 ppm (sample 1), a chlorine dioxide solution having a concentration of 30 ppm (sample 2), and a chlorine dioxide solution having a concentration of 50 ppm (sample 3) were prepared. Used cloth (test piece) containing spores in advance was added, and after a predetermined period of time, the number of viable bacteria per 1 mL of a washing solution obtained by washing the used cloth with SCDLP medium containing sodium thiosulfate was measured. The details are described below.

1. Specimen 1) Chlorine dioxide adjusting solution A (drug A)
2) Chlorine dioxide adjusting solution B (drug B)
3) Chlorine dioxide adjusting solution C (drug C)
4) Used cloth (5 × 10cm)

2. Preparation of sample 1) Chlorine dioxide solution 10ppm (sample 1)
Samples 1) to 3) were added to 48.5 mL of purified water kept at 50 ° C. ± 1 ° C. in order of 0.5 mL at intervals of 15 to 30 seconds. That is, 0.5 mL of each of the drugs A, B, and C is added to 48.5 mL of purified water kept at a predetermined temperature at predetermined time intervals to generate a high-concentration chlorine dioxide solution. Next, 0.54 mL of the produced high-concentration chlorine dioxide solution was added to 4.86 mL of purified water kept at a predetermined temperature, and a 10-fold diluted chlorine dioxide solution having a concentration of 30 ppm was produced to obtain Sample 1.

2) 30 ppm of chlorine dioxide solution (sample 2)
Samples 1) to 3) were successively added to 48.5 mL of purified water kept at 50 ° C. ± 1 ° C. at intervals of 15 to 30 seconds, and 1.5 mL of each was added to make a 10-fold dilution in 15 to 30 seconds. That is, 1.5 mL of each of the drugs A, B, and C is added to 48.5 mL of purified water kept at a predetermined temperature at predetermined time intervals to generate a high-concentration chlorine dioxide solution. Next, 0.54 mL of the produced high-concentration chlorine dioxide solution was added to 4.86 mL of purified water kept at a predetermined temperature, and a 10-fold concentration-diluted 10 ppm chlorine dioxide solution was produced to obtain Sample 2.

3) 50 ppm of chlorine dioxide solution (sample 3)
Samples 1) to 3) were added to 48.5 mL of purified water kept at 50 ° C. ± 1 ° C. in order of 2.5 mL at intervals of 15 to 30 seconds, and the dilution was 10-fold diluted within 15 to 30 seconds. That is, 2.5 mL of each of the drugs A, B, and C is added to 48.5 mL of purified water kept at a predetermined temperature at predetermined time intervals to generate a high-concentration chlorine dioxide solution. Next, 0.54 mL of the produced high-concentration chlorine dioxide solution was added to 4.86 mL of purified water kept at a predetermined temperature, and a 50-ppm concentration-diluted chlorine dioxide solution was diluted 10-fold to obtain Sample 3.

3. Preparation of test piece 0.1 mL of the test bacterial solution was inoculated in several drops onto one sample 4) air-dried after high-pressure steam sterilization (121 ° C., 15 minutes) and air-dried at room temperature for 1 to 2 hours. That is, 0.1 mL of the test bacterial solution containing the spore bacterium was inoculated into three drops of high pressure steam sterilized old cloth in several drops to prepare test pieces 1, 2, and 3.

4. Test Overview Test pieces 1, 2, and 3 were added to samples 1, 2, and 3, respectively. After a predetermined time, the test pieces 1, 2, and 3 were taken out of each of the samples 1, 2, and 3, and washed with an SCDLP medium containing 0.75% sodium thiosulfate, and the number of viable bacteria per 1 mL of the washed liquid was measured. In addition, a preliminary test (confirmation of neutralization conditions) was performed in advance to confirm conditions under which the viable cell count could be measured without being affected by the sample. The number of measurements was three.

5. Test results

  As is clear from Table 1, the test pieces added to the chlorine dioxide solution having a concentration of 30 ppm (sample 2) and the chlorine dioxide solution having a concentration of 50 ppm (sample 3) do not detect the viable cell count in 1 / mL. It can be seen that the detection is extremely slight. On the other hand, it can be seen that the test piece added to the chlorine dioxide solution (sample 1) having a concentration of 10 ppm has a large number of viable bacteria remaining in 1 / mL. In Table 1, the control is purified water, and the number of viable bacteria in the purified water is shown.

  As described above, according to the present embodiment, microorganisms including Bacillus cereus can be reliably sterilized by washing with washing water containing chlorine dioxide. Further, since a solution containing chlorine dioxide having a predetermined concentration by diluting high-concentration chlorine dioxide with water is used as washing water, there is no need to provide a sterilization tank or a disinfection tank separately from the washing tub 3.

  In addition, according to the present embodiment, since high-concentration chlorine dioxide is generated and then injected into the washing tub 3 of the washing machine 2 for dilution, transport of high-concentration chlorine dioxide and long-term storage are not required, and Becomes easier.

  Further, by disposing the sterilizer 6 near the washing machine 2, the generated high-concentration chlorine dioxide can be quickly diluted with the washing water in the washing tub 3, and the high-concentration chlorine dioxide can be safely handled. be able to.

  Also, since high-concentration chlorine dioxide is diluted with washing water to a concentration that does not damage the items to be washed, there is no need to use fresh water to dilute the chlorine dioxide, and water is saved in the washing operation. Can be.

[Other embodiments]
Next, another embodiment shown in FIG. 4 will be described. In another embodiment shown in FIG. 4, the sterilizing apparatus 6 using the above-described sterilizing method is applied to the finishing tub 19 of the continuous washing machine 18. As shown in FIG. 4, the continuous washing machine 18 is provided with a pre-washing tub 20, a plurality of washing tubs 21, a plurality of rinsing tubs 22, and a finishing tub 19 in a continuous manner. The pre-wash tank 20 is provided with an inlet 23 into which an object to be washed is charged. The pre-wash tub 20, the washing tub 21, the rinsing tub 22, and the finishing tub 19 are connected to pipes (not shown) for supplying pre-washing water, washing water, rinsing water, and finishing water, respectively. A drain line for discharging pre-wash water, wash water, rinse water, and finish water after washing, rinsing, and finish washing is provided.

  Further, the other side of the pipe line 16 of the injection diluting unit 8 that is connected to one side of the reaction tank 10 is connected to the finishing tank 19. Then, high-concentration chlorine dioxide generated in the reaction tank 10 of the sterilizer 6 is injected into the finishing tank 19 through the pipe 16. In the finishing tank 19, finishing water (washing water) for finishing the article to be washed is supplied, and the finishing water dilutes high concentration chlorine dioxide. The concentration of chlorine dioxide diluted in the finishing tank 19 is set to 20 to 50 ppm as in the above embodiment. For example, if the amount of the finishing water is 200 L, chlorine dioxide generated by mixing 240 g of the chemicals A, B, and C in the reaction tank 10 in total of 240 g is injected into the finishing tank 19 and diluted.

  Also in the present embodiment, the same effects as in the above-described embodiment can be obtained. By washing with washing water containing chlorine dioxide, microorganisms including Bacillus cereus can be reliably sterilized. Further, since a solution containing chlorine dioxide having a predetermined concentration by diluting high-concentration chlorine dioxide with water is used as washing water, there is no need to provide a sterilization tank or a disinfection tank separately from the washing tub.

[Another Embodiment of Sterilizer]
Next, another embodiment of the sterilizer will be described. As shown in FIG. 5, the sterilizing apparatus 26 according to the present embodiment includes a chlorine dioxide generation unit 27 that mixes a plurality of drugs A, B, and C to generate high concentration chlorine dioxide, and a chlorine dioxide generation unit 27. And an injection diluting unit 28 for injecting the high-concentration chlorine dioxide generated in the above into the washing tub 3 and diluting it to a predetermined concentration.

  The chlorine dioxide generation unit 27 is configured to store a plurality of medicines A, B, and C, respectively, a plurality of medicine storage tanks 29 (29a, 29b, and 29c), and the plurality of medicines A, B, and C and water are injected and reacted. A reaction tank 30 for producing high-concentration chlorine dioxide, a plurality of drug injection pumps 31 (31a, 31b, 31c) for injecting a predetermined amount of drug in the plurality of drug storage tanks 9 into the reaction tank 30, respectively; It is formed with.

  Each chemical storage tank 29 is communicated with an inlet 33 (33a, 33b, 33c) of the reaction tank 30 by a pipe 32 (32a, 32b, 32c). The inlets 33 are respectively provided in pipes 34 for sending air to the reaction tank 30. Each of the drug injection pumps 31 (31a, 31b, 31c) is provided in the middle of each of the conduits 32a, 32b, 32c.

  The reaction tank 30 includes a pipe 34 to which air is supplied, a cylindrical reaction tank main body 30 a having the pipe 34 communicated at an upper part, a ball check valve 35 communicating at a lower part of the reaction tank main body 30 a, and a ball. And a conduit 36 communicating with the check valve 35. In the conduit 34, injection ports 33a, 33b, 33c are formed. The injection port 33a and the medicine storage tank 29a communicate with each other through a pipe 32a, the injection port 33b and the medicine storage tank 29b communicate with each other through a pipe 32b, and the injection port 33c and the medicine storage tank 29c communicate with each other through a pipe 32c.

  Then, the medicine A is injected into the pipe 34 from the medicine storage tank 29a through the injection port 33b by the medicine pump 31a, and is sent into the reaction tank 30 by air. The medicine B is injected into the pipeline 34 from the medicine storage tank 29b through the injection port 13b by the medicine pump 31b, and is sent into the reaction tank 30 by air. The medicine C is injected into the pipe 34 from the medicine storage tank 29c through the injection port 33c by the medicine pump 31c, and is sent into the reaction tank 30 by air.

  One end of a ball check valve 35 is connected to the lower part of the reaction tank main body 30a, and a T-shaped pipe 36 is connected to the other end of the ball check valve 35. One opening of the pipe 36 is a water supply port 36a to which water is supplied. The other opening of the conduit 36 is an input port 36b through which the mixed liquid of the medicines A, B, and C is sent to the injection diluting section 28 by the water supplied from the water supply port 36a. The other end of the ball check valve 35 is connected to an intermediate portion between the water supply port 36a and the charging port 36b.

  Then, when the medicines A, B, and C are substantially simultaneously injected into the conduit 34, they are mixed in the conduit 34. The mixed solution mixed in the pipe 34 is fed under pressure into the reaction tank 30 by the air supplied in the pipe 34. The mixed liquid in which the medicines A, B, and C are mixed is pressurized in the reaction tank 30. When the pressure in the reaction tank 30 reaches a predetermined pressure, the mixed solution passes through a ball check valve 35 and is pumped into a pipe 36. The mixed solution pumped into the pipe 36 is sent from the inlet 36b to the injection diluting unit 28 and diluted by the water supplied from the water supply port 36a.

  The injection diluting section 28 is constituted by the washing tub 3 of the washing machine 2 and a pipe 37 for communicating the washing tub 3 with the reaction tub 10. In the washing tub 3, an object 1 to be washed and washing water (rinsing water) for washing (rinsing) the object 1 are stored in advance. A mixed solution containing high-concentration chlorine dioxide generated in the reaction tank 30 is injected into the washing tub 3, and the high-concentration chlorine dioxide is diluted with washing water. In the present embodiment, the concentration of chlorine dioxide in the washing tub 3 is set to 30 to 50 ppm. The addition rate of each of the medicines A, B, and C is about 0.04% of the amount of water in the washing tub 3. For example, if the amount of water in the washing tub 3 is 200 L, each of the medicines A, B, and C is 80 g. is there. Therefore, chlorine dioxide generated by mixing 80 g × 3 = 240 g is diluted with 200 L of water, and the dilution ratio becomes 830 times.

  Before dilution with the washing water in the washing tub 3, the concentration of chlorine dioxide is inevitably extremely high at 20,000 ppm, and therefore, there is a danger in handling. At present, water is added before adding each of the drugs A, B, and C. It has been diluted in advance. That is, the mixed solution pumped from the reaction tank 30 is diluted in advance by injecting water through the pipe 36. If the concentration of chlorine dioxide is about 4000 to 10000 ppm, it is easy to handle, so if about 1 L of water is put in the reaction tank 10, it is diluted about 4 times and the concentration becomes about 5000 ppm, making it easy to handle. Become.

  According to the present embodiment, as in the above-described embodiment, by washing with washing water containing chlorine dioxide, microorganisms including Bacillus cereus can be reliably sterilized. Further, since a solution containing chlorine dioxide having a predetermined concentration by diluting high-concentration chlorine dioxide with water is used as washing water, there is no need to provide a sterilization tank or a disinfection tank separately from the washing tub 3.

  In addition, according to the present embodiment, since high-concentration chlorine dioxide is generated and then injected into the washing tub 3 of the washing machine 2 for dilution, transport of high-concentration chlorine dioxide and long-term storage are not required, and Becomes easier.

  Further, by disposing the sterilizer 6 near the washing machine 2, the generated high-concentration chlorine dioxide can be quickly diluted with the washing water in the washing tub 3, and the high-concentration chlorine dioxide can be safely handled. be able to.

  Also, since high-concentration chlorine dioxide is diluted with washing water to a concentration that does not damage the items to be washed, there is no need to use fresh water to dilute the chlorine dioxide, and water is saved in the washing operation. Can be.

  Further, in the present embodiment, by disposing the reaction tank main body 30a in a vertical shape and communicating the pipe 34 at the upper portion, the medicine A injected into the pipe 34 from the injection ports 33a, 33b, 33c, Since B and C flow into the reaction tank main body 30a by gravity, the medicines A, B and C do not flow backward. In addition, since air is supplied to the pipe 34, the mixed liquid in which the medicines A, B, and C are mixed can be pumped into the reaction tank main body 30a in the pipe 34. It can be reliably fed into the reaction tank main body 30a.

  In addition, the current cleaning business law enforcement regulations use steam disinfection, hot water disinfection, formaldehyde gas disinfection, ethylene oxide gas disinfection, phenol carbonate disinfection, cresol disinfection, formalin water disinfection, sodium hypochlorite, etc. Each method with an advantageous chlorine concentration of 250 ppm is mentioned, but cresol, calcified water disinfection does not work on spores, formalin water has carcinogenicity, formaldehyde gas, ethylene oxide gas in addition to carcinogenicity, In the first place, it cannot be used in commercial washing machines due to the fumigation method, and there is no effect on B. cereus in disinfection with boiling water.

  In other words, the method which has an effect on Bacillus cereus and is practically usable or currently used in a commercial washing machine has only 250 ppm of sodium hypochlorite. However, in general, when considering the antimicrobial spectrum of sodium hypochlorite, it is said that it is desirable to maintain a concentration that is sufficiently effective against spores including Bacillus cereus at a concentration of 1000 ppm or more. Therefore, 250 ppm does not always provide a reliable bactericidal effect.

  On the other hand, when sodium hypochlorite of 250 ppm or more is used in a commercial washing machine, there is also a bad influence on metal corrosiveness and linen materials. According to the sterilization method using chlorine dioxide which can be realized by the present embodiment, the necessary concentration is, as apparent from the test results of the food analysis center, 10 to 50 ppm is sufficient, and the method using sodium hypochlorite is sufficient. In comparison, a bactericidal effect is obtained at a concentration of 1/10 or less.

In addition, chlorine dioxide has a lower oxidation-reduction potential than sodium hypochlorite and ethylene oxide gas, so it has less adverse effects such as corrosion on metals.In addition, sodium hypochlorite is affected by pH. As a result, the bactericidal effect is drastically reduced. For example, in the case of alkalinity, hypochlorite ion becomes dominant, and the effect is reduced to 1/10 or less.
On the other hand, chlorine dioxide maintains a bactericidal effect irrespective of the pH, and thus is considered to be the most suitable bactericidal method for a commercial washing machine that often uses an alkaline chemical.

  As described above, the embodiments of the present invention have been disclosed. However, it is apparent that those skilled in the art can make changes without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

  INDUSTRIAL APPLICABILITY The method for sterilizing an object to be washed according to the present invention can be used in a washing machine having a washing tub to which washing water for washing an object to be washed is supplied.

DESCRIPTION OF SYMBOLS 1 Washing thing 2 Washing machine 3 Washing tub 4 Chlorine dioxide generation process 5 Injection dilution process 10 30 Reaction tank 18 Continuous washing machine 19 Finishing tub

Claims (10)

Used in a washing machine for washing an object to be washed, a method for sterilizing an object to be washed in an industrial washing machine for sterilizing the object to be washed in a washing tub of the washing machine,
A chlorine dioxide producing step of mixing water and a plurality of chemicals to produce a high concentration of chlorine dioxide;
An injection dilution step of injecting high-concentration chlorine dioxide generated in the chlorine dioxide generation step into the washing tub and diluting the washing target in the washing tub to a predetermined concentration with washing water for washing. A method for sterilizing an object to be washed in a commercial washing machine.   In the chlorine dioxide generation step, water is supplied into the mixing reaction tank in advance, and then the plurality of drugs are injected into the reaction tank in a predetermined order, and the plurality of drugs and water injected into the reaction tank are mixed with each other. The method according to claim 1, wherein the mixture is injected into the washing tub. The concentration of the chlorine dioxide diluted with the washing water in the washing tub is in a range of 10 ppm to 100 ppm, and the chlorine dioxide is brought into contact with an object to be washed for 90 seconds or more. 3. The method for sterilizing an object to be washed of a commercial washing machine according to item 1.
  The commercial liquid according to any one of claims 1 to 3, wherein the mixed solution of water and the plurality of chemicals generated in the chlorine dioxide generating step has a hydrogen ion index of 5 to 7. Washing machine sterilization method for washing machine.   The commercial washing machine according to any one of claims 1 to 4, wherein the plurality of chemicals are a chlorite solution, a hypochlorite solution, and an acid solution. To sterilize the object to be washed.   The method according to claim 5, wherein the chlorite solution is a sodium chlorite solution, the hypochlorite solution is a sodium hypochlorite solution, and the acid solution is a citric acid solution. A method for sterilizing items to be washed in a commercial washing machine.   0.002 to 0.02% of sodium chlorite, 0.001 to 0.01% of sodium hypochlorite, and 0.001 to 0.01% of citric acid with respect to the washing water in the washing tub. The method according to claim 6, wherein the injection is performed at a rate of 0.1%. Used in a washing machine for washing an object to be washed, a sterilizing apparatus for sterilizing the object to be washed in a washing tub of the washing machine,
A chlorine dioxide generator that mixes water and a plurality of chemicals to produce a high concentration of chlorine dioxide;
A sterilizing device comprising: an injection diluting unit for injecting high-concentration chlorine dioxide generated in the chlorine dioxide generating unit into the washing tub and diluting the same to a predetermined concentration.   A plurality of medicine storage tanks each storing a plurality of medicines, a reaction tank in which the plurality of medicines are injected and react to generate chlorine dioxide, and a predetermined amount in the plurality of medicine storage tanks. 9. The sterilization apparatus according to claim 8, wherein the sterilization apparatus is formed by a plurality of drug injection pumps for injecting the respective drugs into the reaction tank in a predetermined order. Washing machine for washing the washing object, a high concentration of dioxide generated by the chlorine dioxide generation process definitive to be washed product sterilization method of industrial washing machine according to any one of claims 7 from the claim 1 A mixed solution containing chlorine is injected into the washing tub, and the washing is sterilized while washing the washing target in a state where the mixed solution is diluted to a predetermined concentration with the washing water stored in the washing tub. A commercial washing machine using a method for sterilizing an object to be washed of a commercial washing machine.

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