A commercial washing machine equipped with a method and means for disinfecting laundry

Abstract

To provide a method and a device for enabling laundry in a washing tub to be safely and adequately disinfected even in a continuous washing machine with a high processing speed in relation to a method and a device for disinfecting laundry in a tub of a dewatering washing machine and the continuous washing machine with slightly acidic chlorine-containing water.SOLUTION: Chlorine-containing water fed into a tub to be disinfected is slightly acidified by a carbonic acid gas supplied from a carbonic acid gas supplier 7. The carbonic acid gas and the chlorine-containing water are simultaneously and independently supplied to disinfection tubs 18, 19 for disinfecting the laundry or an inflow pipe 31a for supplying new water, recycled water and circulation water into the disinfection tubs.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for disinfecting laundry in a washer / extractor and a tunnel washing machine, and to a commercial washing machine suitable for carrying out the disinfection method. [Background technology]

[0002] As commercial washing machines, mainly used are washer-extractors that sequentially perform a main wash, rinse, and spin cycle in a washing drum, and continuous washing machines that wash laundry by transferring it from a main wash region to a rinse region in a washing drum equipped with multiple washing tubs. Meanwhile, as a method for disinfecting various items, a disinfection method using slightly acidic chlorine-containing water is known, and a method or device for disinfecting laundry by supplying slightly acidic chlorine-containing water to a tub called a final rinse tub, finishing tub, disinfection tub, processing tub, etc., subsequent to the rinsing region of a continuous washing machine has also been proposed.

[0003] The bactericidal power of chlorine-containing water is greatly affected by the pH of the aqueous solution, and is strongest in the slightly acidic to weakly acidic range around pH 5, where the content of hypochlorous acid is high, and the stability of hypochlorous acid is also higher than on the strongly acidic side. Therefore, in chlorine-containing water that uses hypochlorous acid as a bactericidal component, for example, acetic acid or carbonic acid is added to adjust the aqueous solution to a slightly acidic state.

[0004] Patent Document 1 points out that the washing water in the rinse zone of a continuous washing machine contains residual alkaline components from the detergents and chemicals used in the main wash, and that even if hypochlorous acid-containing water obtained by adjusting the pH to a preferred level by adding acetic acid or carbonic acid is supplied, the pH rises due to the residual alkaline components, and the disinfecting effect is not fully exerted.As a means of solving this problem, the patent proposes a technology to quickly lower the pH value in a disinfection tank by supplying hypochlorous acid-containing water slightly acidified with an acid aqueous solution to the disinfection tank before supplying the hypochlorous acid-containing water.As an acid to neutralize the residual alkaline components, an acid aqueous solution such as citric acid or acetic acid, which is the same acid that slightly acidifies the hypochlorous acid-containing water, is used.

[0005] Patent Document 2 proposes a method for sterilizing items to be washed, which includes a step of putting the items to be washed into a sterilization / disinfection tank capable of rinsing the items, and a chemical rinsing step of putting a chemical consisting of slightly acidic hypochlorous acid mixed water into the tank and rinsing the items to be washed together with the chemical in the sterilization / disinfection tank. It shows that diluted hydrochloric acid or carbonic acid is used as the acid that makes the hypochlorous acid mixed water slightly acidic.

[0006] Patent Document 3 also proposes providing a disinfection tank between the rinsing tank and the finishing tank of a continuous washing machine or after the finishing tank, i.e., between the finishing tank and the spin dryer, and injecting fresh water and hypochlorous acid into these disinfection tanks.

[0007] On the other hand, Patent Document 4 proposes a technology for producing weakly acidic chlorine-based sterilizing water used for sterilizing kitchen utensils, food, medical equipment, etc., in which carbon dioxide gas is supplied in the form of gas or dry ice to an aqueous solution of sodium hypochlorite to adjust the pH, thereby producing slightly acidic chlorine-based sterilizing water with a pH of about 5, and it is stated that carbon dioxide gas is readily available and does not require significant care in its handling.

[0008] In contrast to this, Patent Document 5 states that the method of bubbling carbon dioxide gas from a spray pipe inside a tank as described in Patent Document 4 has problems such as taking a long time to adjust the pH and dissolving the carbon dioxide gas inefficiently because some of the gas is discharged. Therefore, Patent Document 5 proposes a method for producing a slightly acidic disinfectant, which is characterized by producing carbonated water by supplying water and carbon dioxide gas to a carbon dioxide gas dissolver having a means (static mixer) for mixing water and carbon dioxide gas within the water flow path, and then supplying a disinfectant to the carbonated water from a disinfectant supply means. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-112469 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-209242 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-119089 [Patent Document 4] Japanese Patent Application Publication No. 10-24294 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-305472 Summary of the Invention [Problem to be solved by the invention]

[0010] There is a strong demand for commercial washing machines to shorten washing times and improve work efficiency. In a continuous washing machine that can efficiently wash a wide variety of laundry, increasing the number of tubs in the main wash area and the rinse area can make washing more efficient, but this shortens the residence time of the laundry in each tub (cycle time), and also shortens the time available for disinfecting the laundry.

[0011] The inventors of the present application have studied the disinfection method proposed in Patent Document 1 for a continuous washing machine with a short cycle time and multiple tanks, and have also studied the methods proposed in Patent Documents 4 and 5 for a supply device for a slightly acidic chlorine aqueous solution, but have found it difficult to obtain a satisfactory disinfection effect.

[0012] In other words, in commercial washing machines, various chemicals such as detergents, auxiliaries, and bleaches are used during the main wash depending on the type of laundry and the type of dirt put in, but organic dirt adhering to the laundry, alkaline components contained in the detergents and auxiliaries, and hydrogen peroxide contained in the bleach remain in the wash water in the treatment tank where disinfection is to be performed, and the types and amounts of these chemicals change depending on the type and amount of laundry put in successively, so it was difficult to adjust in a short time the amount of carbon dioxide gas to be mixed into the slightly acidic chlorine aqueous solution and the amount of slightly acidic chlorine-containing water to be supplied to the treatment tank depending on the type and amount of residual chemicals.

[0013] Furthermore, in order to disinfect laundry, it is not enough to simply adjust the wash water in the treatment tank to an appropriate pH value and chlorine concentration; it takes even more time for the pH value and chlorine concentration of the wash water contained in the fibers of the laundry to reach the appropriate values, and it is difficult to simultaneously adjust both to the appropriate values, which creates the problem that the laundry itself cannot be properly disinfected in a short period of time.

[0014] Furthermore, Patent Document 1 states that a sufficient disinfecting effect can be obtained by mixing a low-concentration chlorine aqueous solution such as sodium hypochlorite as a disinfectant (for example, a chlorine concentration of about 30 mg / L) with fresh rinse water, and then adding an acid aqueous solution to create a slightly acidic hypochlorous acid solution. However, in continuous washing machines with many tubs, the cycle time is short, so laundry cannot be sufficiently disinfected with such a low chlorine concentration. Furthermore, the method of adjusting the pH of hypochlorous acid-containing water with an acid aqueous solution such as citric acid or acetic acid has the problem that chlorine gas may be generated, making it difficult to safely adjust the pH.

[0015] In tests conducted by the inventors of this invention, the residual concentrations of hydrogen peroxide and detergent remaining in the wash water contained inside the laundry were found to be different from the residual concentrations in the wash water in the disinfection tub. Due to this difference, it was difficult to determine whether the adjustment had been made correctly simply by measuring the pH and chlorine concentration of the wash water in the tub immediately after supplying chlorine-containing water and carbon dioxide gas, which could result in inadequate disinfection.

[0016] This invention has been made to solve the above-mentioned problems that were discovered through various tests using an actual machine to verify the disinfection method described in Patent Document 1, and its object is to provide a method that can adjust the chlorine concentration and pH value of the wash water in the washing tub, and even in the fibers of the laundry, to appropriate values ​​in a short time in order to disinfect laundry in a short time, thereby more safely and appropriately disinfecting laundry in the washing tub even in a continuous washing machine with a fast processing speed, and a commercial washing machine that is suitable for using this method. [Means for solving the problem]

[0017] The method for disinfecting laundry of this invention is an improvement over the method of disinfecting laundry in washing tubs 18, 19 in the rinsing area of ​​a continuous washing machine or in washing tub 1b in the rinsing step of a washer / extractor with slightly acidic chlorine-containing water, i.e., a chemical obtained by making chlorine-containing water in which a 12% aqueous solution of sodium hypochlorite or other chlorine agent is dissolved slightly acidic, so that laundry in disinfection tubs 18, 19, 1b where laundry is to be disinfected can be disinfected more safely and reliably in a short time without generating chlorine gas.

[0018] In the method for disinfecting laundry of this invention, chlorine-containing water is made slightly acidic by carbon dioxide gas supplied from the carbon dioxide gas supply device 7. Carbon dioxide gas and chlorine-containing water are supplied simultaneously and individually to the disinfection tank 18, 19, 1b where laundry is to be disinfected or to the inlet pipe 31 (31a, 31b, 31c) which supplies new water, recovered water, or circulated water to the disinfection tank.

[0019] In continuous washing machines with many tubs, the cycle time is short, so in order to obtain a sufficient disinfection effect, it is desirable to supply the carbon dioxide gas and chlorine-containing water necessary to generate a large amount (for example, 100 L / min or more) of hypochlorous acid water with a high chlorine concentration (preferably 100 ppm or more) in a short time (practically around 2 minutes).

[0020] The disinfection tank may be the final rinse tank 18 of a continuous washing machine, the processing tank 19, or a tank dedicated to disinfection provided separately from these, or the washing tank 1b of a washer / extractor at the end of the rinse process. The supplied chlorine-containing water and carbon dioxide gas are mixed by the shaking or rotation of the disinfection tank or the flow of water through the inlet pipe 31 to become slightly acidic chlorine-containing water.

[0021] The carbon dioxide gas and the chlorine-containing water can be supplied separately to the disinfection tank, or both can be supplied separately to the inlet pipe 31 to the disinfection tank, or one of them can be supplied to the disinfection tank and the other can be supplied to the inlet pipe 31 to the tank.

[0022] In continuous washing machines that do not spin-dry the laundry between the main wash and rinse, residual alkaline components from detergents and other chemicals used in the main wash in the rinse water in the disinfection tub may raise the pH of the slightly acidic chlorine-containing water and inhibit disinfection, as pointed out in Patent Document 1. This problem can be solved by supplying a neutralizer to adjust the pH of the wash water before supplying chlorine-containing water and carbon dioxide gas to the disinfection tub, or to the previous tub or washing tub in the previous process (hereinafter referred to as the "pre-disinfection tub").

[0023] In addition, in a continuous washing machine equipped with a spin dryer installed near the laundry outlet, a pH meter 42 and a chlorine concentration meter 44 are provided in the spin dryer tank 21 to detect the chlorine concentration and pH value of the spin dryer wastewater, preferably the wastewater in the later stage of spin drying, and these detected values ​​are displayed so that the amounts of chlorine-containing water, carbon dioxide gas, and neutralizing agent supplied can be adjusted manually or by a controller based on these detected values, thereby correcting the difference in water quality between the wash water in the disinfection tank and the wash water inside the fibers of the laundry, thereby enabling more reliable disinfection of the laundry.

[0024] In a washing machine equipped with a controller, a preferred pH value range and chlorine concentration range are registered in the controller, and a pH meter 41 and a chlorine concentration meter 43 are installed in the disinfection tank or the tank next to the disinfection tank (the spin-drying tank 21 when the final tank 19 of a continuous washing machine is the disinfection tank; hereinafter referred to as the "next disinfection tank") to detect the chlorine concentration and pH value of the wash water after chlorine-containing water and carbon dioxide gas are supplied to the disinfection tank, and based on these detected values, the wash water can be drained, new water supplied, a neutralizing agent supplied, etc., thereby enabling safer and more appropriate disinfection of laundry.

[0025] Furthermore, in tests conducted by the inventors of the present application, it was found that when carbon dioxide gas is supplied to water flowing through the inlet pipe 31, it is preferable to provide an ejector 45 to generate negative pressure, and use the negative pressure to suck in carbon dioxide gas and mix it with the water flowing through the ejector 45. If necessary, a mixer 49 can also be provided downstream of the ejector 45. When chlorine-containing water is also supplied into the same pipe, the chlorine-containing water is supplied upstream of the ejector 45. [Effects of the Invention]

[0026] According to this invention, laundry can be reliably disinfected in a washing tub in a short time, particularly in a disinfection tub installed in a continuous washing machine with a short cycle time, and the disinfection of laundry can be more reliably performed, and the pipes through which rinse water containing slightly acidic chlorine-containing water flows and the recovery tanks 3 and 4 can also be disinfected. Furthermore, carbon dioxide gas has the effect of stabilizing the pH within a weakly acidic range (pH 5 to 6.5), and even if an excessive amount is added, the pH will not drop below 4, so there is no risk of chlorine gas being generated. [Brief explanation of the drawings]

[0027] [Figure 1] Block diagram showing a first embodiment of a tunnel washing machine [Figure 2] Flowchart showing the control procedure for the washing machine in Figure 1 [Figure 3] Block diagram showing the main parts of the washing machine in Figure 1 [Figure 4] A block diagram showing the main parts of a second embodiment of a continuous washing machine. [Figure 5] A block diagram showing the main parts of a third embodiment of a continuous washing machine. [Figure 6] A block diagram showing the main parts of a fourth embodiment of a continuous washing machine. [Figure 7] A block diagram showing the main parts of a fifth embodiment of a continuous washing machine. [Figure 8] A block diagram showing the main parts of a sixth embodiment of a washer-extractor. [Figure 9] A block diagram showing the main parts of a washing and drying machine according to a seventh embodiment. [Figure 10] A block diagram showing the main parts of an eighth embodiment of a washer-extractor. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 shows an example of a single-drum continuous washing machine equipped with a nine-tank washing drum 1a, in which the first tank is a pre-wash tank 11, the second tank 12 to the fifth tank 15 are main wash tanks (tanks in the main wash area), the sixth tank 16 to the ninth tank 19 are tanks in the rinse area, the sixth tank 16 is the first rinsing tank, the eighth tank 18 is the last rinsing tank, and the ninth tank 19 is a tank called a processing tank. Laundry washed in the washing drum 1a and containing a large amount of wash water is dehydrated in a dehydrator 2. In the figure, the dehydrator 2 is shown positioned away from the washing drum 1a, but in reality it is located adjacent to a discharge chute 26 for laundry from the processing tank 19.

[0029] Of the nine tanks, the second tank 12 to the third tank 13, the sixth tank 16, the eighth tank 18, and the ninth tank 19 have a double structure equipped with an outer barrel 10. The peripheral wall of the rotating drum (inner barrel) where the outer barrel 10 is installed has punched holes (shown by the broken lines in the figure), and the pipes connected to the outer barrel 10 of these tanks are used to supply and drain steam and water, as well as detergent, bleach, disinfectant, and other chemicals.

[0030] In the embodiment of Fig. 1, the final rinsing tank 18 is a disinfection tank. A new water inlet pipe 31a and a new water piping 32 are connected to the final rinsing tank 18 and the processing tank 19, which is a tank subsequent to disinfection, respectively, and recovered water from the processing tank 19 and the dehydrator tank 21 is recovered into the cold water recovery tank 3 through recovery pipes 34, 35, respectively, and the recovered water is supplied to the final rinsing tank 18 through the cold water inlet pipe 31b by the water supply pump 53a. The recovered water in the cold water recovery tank 3 can also be supplied to the pre-wash tank 11 from the laundry inlet 25 through the recovered water piping 36 by the water supply pump 53b.

[0031] The rinse water supplied to the final rinse tub 18 through the new water inlet pipe 31a and the cold water inlet pipe 31b flows countercurrently in the direction opposite to the laundry transport direction, and is discharged from an overflow pipe 56 connected to the outer body 10 of the first rinse tub 16 through piping 37 into the hot water recovery tank 4. The partitions between the rinse tubs 16-18 are provided with punched holes (shown by dashed lines in the drawing) to allow the rinse water to flow through.

[0032] The hot water stored in the hot water recovery tank 4 is supplied as main wash water to the main wash tubs 12 and 13 selected by opening and closing the appropriate solenoid valves 65 and 66 through the water supply pump 54a and hot water piping 38. The recovered water in the hot water recovery tank 4 is also supplied to the laundry inlet 25 through the hot water piping 39 by the water supply pump 54b and is used as pre-wash water.

[0033] The main washing tanks 12 and 13 equipped with the outer shell 10 are connected to a water collection pipe 51 by respective drain pipes equipped with drain valves (solenoid valves). One end of the water collection pipe 51 is provided with a drain outlet 52, and the other end is connected to the high-temperature water tank 5. The main washing wastewater heated to, for example, about 60°C by steam supplied from a steam pipe (not shown) is stored in the high-temperature water tank 5.

[0034] A sodium hypochlorite container 6 is connected via a chemical supply pump 46 to the new water inlet pipe 31a connected to the final rinse tank 18, which serves as a disinfection tank, and a carbon dioxide cylinder 7 is connected downstream of this via a solenoid valve 72. When solenoid valves 67, 68 are opened with solenoid valves 69, 71 closed, new water is supplied to the disinfection tank 18. When the chemical supply pump 46 is operated in this state and solenoid valve 72 is opened, sodium hypochlorite is supplied to the new water supplied to the disinfection tank 18, and carbon dioxide at a pressure set by the pressure setting valve 74 is drawn by the negative pressure of the new water passing through the ejector 45, further mixed by the mixer 49, and supplied to the disinfection tank 18, where it mixes with the wash water in the tank and makes the water in the tank slightly acidic.

[0035] In the embodiment of Figure 1, heat exchanger 9 is connected via solenoid valve 69 to new water inlet pipe 31a to final rinse tank 18. When high-temperature water pump 55 is operated, solenoid valve 68 is closed, and solenoid valve 69 is opened, new water heated by heat exchanger 9 is supplied to disinfection tank 18. When chemical supply pump 46 is operated in this state and solenoid valve 72 is opened, new water that has been heated and in which sodium hypochlorite and carbon dioxide have been mixed is supplied to disinfection tank 18. The main-wash wastewater stored in high-temperature water tank 5 is sent to heat exchanger 9 by high-temperature water pump 55 when disinfecting laundry, and is used as a heat source for heating the new water to be supplied to disinfection tank 18.

[0036] A sodium hypochlorite container 6 is connected to the processing tank 19, which is a post-disinfection tank, via a chemical supply pump 47. By operating the chemical supply pump 47, sodium hypochlorite is supplied to the processing tank 19.

[0037] The final rinsing tank 18 and the processing tank 19 are connected to the neutralizing agent container 8 via a chemical supply pump 48 and respective solenoid valves 63, 64. By operating the chemical supply pump 48 and opening the solenoid valve 63, the neutralizing agent is supplied to the final rinsing tank 18, and by operating the chemical supply pump 48 and opening the solenoid valve 64, the neutralizing agent is supplied to the processing tank 19.

[0038] The neutralizing agent is supplied to the final rinse tank 18 to neutralize the pH of the rinse water before supplying hypochlorous acid water, taking into consideration that alkaline components from the detergent and auxiliary agents used in the main wash remain in the wash water (rinse water) in the rinse area (see Patent Document 1). Therefore, the neutralizing agent container 8 can be connected to a tank preceding the tank that serves as the disinfection tank (tank 7 in the example of FIG. 1), or it can be connected to both the tank that serves as the disinfection tank and the tank preceding it in a switchable manner using a solenoid valve, allowing the tank to be supplied with the neutralizing agent to be switched as needed.

[0039] The neutralizer is an aqueous acid solution that neutralizes the alkaline components of the detergent and auxiliary agents used in the main wash, and organic acid solutions such as citric acid, malic acid, acetic acid, and formic acid are generally used in the wash. The amount of acid added is adjusted so that the pH value of the drain water from the spin dryer after rinsing is 5.0 to 7.0, preferably 5.5 to 6.5.

[0040] A pH meter 41 and a chlorine concentration meter 43 are attached to the processing tank 19. The sodium hypochlorite container 6 and the neutralizing agent container 8 are also connected to the processing tank 19 via solenoid valves 62 and 64. The solenoid valves 62 and 64 are operated to adjust the pH value and chlorine concentration value of the rinse water in the processing tank 19. In the apparatus of Figure 1, a pH meter 42 and a chlorine concentration meter 44 are also attached to the dehydrator tank 21 to measure the pH value and chlorine concentration of the dehydrator wastewater.

[0041] Each pipe shown in Figure 1 is provided with a manual valve to be used during maintenance as needed, but these valves are omitted from Figure 1, and only the equipment related to operation control, such as solenoid valves, flow meters, and flow control valves, is shown.

[0042] Next, the washing operation of the washing machine shown in Figure 1, including the disinfection of laundry, will be described. Laundry inserted into inlet 25 is washed in each tank by the oscillation of washing drum 1a for a predetermined time (cycle time, e.g., 3 minutes), and then transferred to the next tank by one rotation per cycle. Immediately after the laundry enters the rinsing area and is transferred to final rinse tank (disinfection tank) 18 via rinsing tanks 16 and 17, solenoid valve 63 opens and chemical supply pump 48 supplies a predetermined amount of neutralizing agent. Next, solenoid valve 67 opens and chemical supply pump 46 operates to supply a predetermined amount of sodium hypochlorite. Solenoid valve 72 opens and carbon dioxide gas metered by pressure setting valve 74 and solenoid valve 72 is supplied to new water inlet pipe 31a by ejector 45. New water containing sodium hypochlorite and carbon dioxide gas is then supplied to final rinse tank 18 via mixer 49. The new water containing sodium hypochlorite and carbon dioxide that flows into the final rinse tank 18 is mixed by the shaking of the washing drum 1a to become slightly acidic hypochlorous acid water, which disinfects the laundry.

[0043] Then, with the next rotation of the washing drum 1a, the laundry in the final rinse tank 18 is sent to the processing tank 19 together with the wash water containing the slightly acidic hypochlorous acid water. In the processing tank 19, the pH value and chlorine concentration value of the rinse water in the tank are measured, and the pH value and chlorine concentration value are adjusted according to the procedure shown in Figure 2.

[0044] That is, the washing drum 1a rotates once and the cycle time in the processing tank 19 for the laundry transferred from the final rinse tank 18 starts 101. When the waiting time for starting the water quality measurement expires 102, it is determined whether the detected chlorine concentration is between the set lower limit and upper limit 103. If the detected chlorine concentration is lower than the lower limit, the amount of chlorine agent required to make the rinse water slightly acidic is calculated and sodium hypochlorite is supplied to the processing tank 19. If the detected chlorine concentration is higher than the set upper limit, the amount of fresh water required to make the rinse water slightly acidic is calculated, and the corresponding amount of rinse water is drained and then the corresponding amount of fresh water is supplied to the processing tank 19 104. After waiting for the chlorine concentration of the rinse water to become uniform 105, the process returns to step 103 to check whether the chlorine concentration is within the specified range.

[0045] If the chlorine concentration is within the specified range, the same procedure (steps 106 to 108) is then followed to check whether the pH value of the rinse water in the processing tank 19 is within the set range (step 106) and make any necessary adjustments (steps 107 to 108) to maintain the pH value and chlorine concentration of the rinse water in the processing tank 19 at a level that will exert a high bactericidal effect, so that the laundry is sufficiently disinfected in the final rinse tank 18, which serves as a disinfection tank, and the processing tank 19 that follows it.

[0046] In a test conducted by the inventors of the present application using a continuous washing machine as shown in Figure 1, in which the final tank 19 of the four tanks in the rinsing area is used as a processing tank and the previous tank, the final rinsing tank 18, is used as a disinfection tank, and rinsing water is passed through in a counterflow manner, when the laundry processing amount per batch was 60 kg, more than 200 L of slightly acidic chlorine-containing water with a chlorine concentration of 100 ppm or more was added per batch.

[0047] The laundry washed and disinfected in this way slides down discharge chute 26 and is placed in basket 23 placed on conveyor belt 22 of dehydrator 2. In dehydrator 2, the laundry in basket 23 is pressed by pressing tool 24 to squeeze out the rinse water contained in the fibers of the laundry, and basket 23 is raised to drive conveyor belt 22, thereby sending the laundry to the dryer for the next process.

[0048] In a continuous washing machine in which laundry is sorted by type, such as towels containing a large amount of wash water in their fibers and sheets containing a small amount, a pH meter 42 and a chlorine concentration meter 44 are also provided in the spin dryer tank 21, and the difference between the detected values ​​of the pH meter 41 and the chlorine concentration meter 43 provided in the processing tank 19 for the same lot and the detected values ​​of the pH meter 42 and the chlorine concentration meter 44 provided in the spin dryer tank 21, particularly at the end of the spin cycle, is registered in the controller for each type of laundry.This makes it possible to estimate the difference in water quality between the rinse water impregnated in the fibers of the laundry and the rinse water in the tank, and to more appropriately control the amounts of neutralizing agent, carbon dioxide, and chlorine-containing water supplied to the final rinse tank 18.

[0049] Figure 3 is a diagram showing the main parts of the chemical supply structure in the embodiment of Figure 1. That is, in the structure of Figure 1, a chlorine agent (sodium hypochlorite) and carbon dioxide gas are mixed together with new water and supplied to the final rinsing tank 18, which serves as a disinfection tank. The processing tank 19 can also be used as a disinfection tank, in which case the chlorine agent and carbon dioxide gas are mixed together with new water and supplied to the processing tank 19. When the chlorine agent and carbon dioxide gas are supplied to the same pipe, it is preferable to supply the chlorine agent upstream of the water flowing through the pipe and supply the carbon dioxide gas via an ejector provided downstream of the chlorine agent.

[0050] 4 to 7 are diagrams showing other examples of the means for supplying the neutralizing agent, chlorine agent, and carbon dioxide gas to the main parts of a continuous washing machine that implements the disinfection method of the present invention, namely, the final rinse tank 18 used as a disinfection tank and the processing tank 19 used as a post-disinfection tank. When carbon dioxide gas is supplied to the piping, the system is designed to suck in the carbon dioxide gas by the negative pressure of the water flowing through the ejector 45, and the neutralizing agent is supplied directly to the target tank, i.e., without being mixed with new water or the like.

[0051] In the example of Figure 4, the structure is such that new water, chlorine agent, and carbon dioxide gas are supplied directly and individually to the final rinsing tank 18, which is used as a disinfection tank. In Figure 4, the structure is such that the processing tank 19 can be used as a disinfection tank, or both the final rinsing tank and the processing tank can be used as disinfection tanks, by opening and closing solenoid valves 61, 72 and 62, 73. When the processing tank 19 is used as a disinfection tank, the neutralizing agent is supplied to the processing tank 19 or the final rinsing tank 18, which is a pre-disinfection tank.

[0052] In the example of Figure 5, sodium hypochlorite, a chlorine agent, is supplied directly to the final rinsing tank 18, which is a disinfection tank, or the processing tank 19, which is a post-disinfection tank, by operating the chemical supply pump 46 and opening and closing solenoid valves 61 and 62, i.e., without being mixed with new water or carbon dioxide gas, and carbon dioxide gas is mixed with new water and supplied to the final rinsing tank 18.

[0053] In the example of Figure 6, the processing tank 19 is used as a disinfection tank, and a circulation pipe 31c is provided to circulate the rinse water in the disinfection tank 19. A sodium hypochlorite container 6 and a carbon dioxide gas cylinder 7 are connected to the circulation pipe, and the chlorine agent and carbon dioxide gas are mixed in the circulation pipe 31c and the processing tank 19 and supplied to the disinfection tank 19.

[0054] The example in Fig. 7 is an example in which a disinfectant water generation unit 57, which is a unitized device for supplying sodium hypochlorite and carbon dioxide gas to the water in the pipe, is attached to the new water inlet pipe 31a. In the example in the figure, a bypass pipe 33 is provided that branches off from the new water inlet pipe 31a and directly supplies new water to the disinfection tank 18, and a flow rate adjustment valve 75 and an opening / closing valve 76 are provided to adjust the ratio of water passing through the disinfectant water generation unit 57 to water passing through the bypass pipe 33.

[0055] When laundry is not disinfected, the on-off valve 76 is closed and new water is supplied from the bypass pipe 33. When disinfection is performed, the on-off valve 76 is opened and new water that has passed through the disinfectant water production unit 57 is supplied, and at this time, the flow rate adjustment valve 75 is appropriately throttled so that some of the new water is also supplied from the bypass pipe 33, and the amount of new water flowing through the disinfectant water production unit 57 can be adjusted to an amount according to the capacity of the disinfectant water production unit 57.

[0056] In the structure of Fig. 7, the disinfectant water generating unit 57 can be manufactured separately from the washing machine, and the amount of water flowing through the disinfectant water generating unit 57 can be adjusted by adjusting the opening of the flow rate adjusting valve 75, so that the disinfectant water generating unit 57 of the same specifications can be used for washing machines of different capacities. Such a structure can also be adopted in the case of the structure of Fig. 6.

[0057] The laundry disinfection method of this invention can be applied not only to a continuous washing machine but also to a washing and spin-drying machine that performs a main wash, rinse, and spin-dry consecutively in one washing tub 1b. Figures 8 to 10 show an embodiment of a washing and spin-drying machine, and the example of Figure 8 has a structure similar to that of Figure 4 for a continuous washing machine, in which fresh water, sodium hypochlorite, and carbon dioxide gas are each directly and separately supplied to the washing tub 1b in the disinfection process.

[0058] FIG. 9 shows a structure in which sodium hypochlorite and carbon dioxide gas are supplied to a new water inlet pipe 31a connected to a washing tub 1b in the rinsing process, and has the same structure as that in FIG. 3 in a continuous washing machine.

[0059] The example of Fig. 10 is a structure in which piping is added to the structure of Fig. 8 to supply carbon dioxide gas directly to washing tub 1b by switching solenoid valves 77 and 78. When carbon dioxide gas is supplied directly to washing tub 1b, only sodium hypochlorite is supplied to the new water, and the sodium hypochlorite aqueous solution and carbon dioxide gas are mixed in washing tub 1b to make it slightly acidic. Also, in the example of Fig. 10, by stopping chemical supply pump 46 and opening solenoid valve 78 with solenoid valve 77 closed, it is possible to supply only carbon dioxide gas into the tub and only adjust the pH of the rinse water in washing tub 1b, so that a neutralizer tank is not required and only carbon dioxide gas can be blown into the tub instead of a neutralizer to neutralize the alkaline components of the detergent and auxiliary agents remaining in the laundry.

[0060] In the example of Figure 10, a pH meter 41 and a chlorine concentration meter 43 are provided at the bottom of the washing tub, and the pH value and chlorine concentration of the rinse water in washing tub 1b can be checked and adjusted using the same procedure as in Figure 2. In the case of a washer-extractor, the time for each process can be set individually, so laundry can be more appropriately disinfected by controlling the time for the disinfection process based on the detected pH value and chlorine concentration.

[0061] In addition, in Figures 8 to 10, a neutralizing agent can be supplied to washing tub 1b, and as in the case of a continuous washing machine, the neutralizing agent is supplied to washing tub 1b before the supply of sodium hypochlorite aqueous solution and carbon dioxide gas. However, in a washer-extractor, drainage and spin-drying are usually performed after each of the main wash and rinse processes. When disinfecting laundry that has been dehydrated after the rinse process, the amount of detergent and auxiliary agents contained in the laundry is thought to be small, and there is no risk that this will significantly change the pH value of the slightly acidic chlorine-containing water. Therefore, it is possible to disinfect the laundry without supplying a neutralizing agent.

[0062] The laundry disinfection method of the present invention can be modified in various ways by referring to the embodiments illustrated in Figures 3 to 10, and the embodiments illustrated for a continuous washing machine can be adopted in a washer-extractor, and conversely, the embodiments illustrated for a washer-extractor can be adopted in a continuous washing machine.Furthermore, as illustrated in Figures 6 and 10, a plurality of embodiments can be implemented by switching between them by switching a solenoid valve or an alternative manual valve. [Explanation of symbols]

[0063] 1(1a, 1b) Washing drum 2 Dehydrator 5. High-temperature water tank 6 Chlorine agent (sodium hypochlorite) container 7 Carbon dioxide gas cylinder (carbon dioxide gas supply device) 8 Neutralizer container 9 Heat exchanger 10 Outer body 16~19 Rinse area tank 18 Final rinse tank 19 Processing tank 21 Dehydrator tank 31a New water inlet pipe 31b Cold water inlet pipe 31c Circulation piping 33 Bypass pipe 41, 42 pH meter 43, 44 Chlorine concentration meter 45 Ejector 49 Mixer

Claims

1. A method for disinfecting laundry in a commercial washing machine, which disinfects laundry in a rinsing area or a washing tub in a rinsing process with slightly acidic chlorine-containing water, The method for disinfecting laundry in a washing machine, characterized in that the slightly acidic chlorine-containing water is obtained by mixing chlorine-containing water and carbon dioxide gas individually supplied to the washing tub or the inlet pipe to the washing tub in the washing tub or the inlet pipe.

2. 2. The method for disinfecting laundry according to claim 1, wherein the chlorine-containing water and carbon dioxide gas are simultaneously and separately supplied to the inlet pipe provided for supplying fresh water to the rinsing area or washing tub during the rinsing step.

3. 2. The method for disinfecting laundry according to claim 1, wherein the carbon dioxide gas is supplied to the inlet pipe for supplying new water to the rinsing area or the washing tub in the rinsing step, and the chlorine-containing water is supplied to the rinsing area or the washing tub in the rinsing step.

4. 2. The method for disinfecting laundry according to claim 1, wherein the chlorine-containing water is supplied to the inlet pipe for supplying new water to the rinsing area or the washing tub in the rinsing step, and the carbon dioxide gas is supplied to the rinsing area or the washing tub in the rinsing step.

5. 2. The method for disinfecting laundry according to claim 1, wherein the chlorine-containing water and the carbon dioxide gas are simultaneously and separately supplied to the rinsing zone or the washing tub in the rinsing step.

6. 2. The method for disinfecting laundry according to claim 1, wherein the carbon dioxide gas is supplied to the inlet pipe provided for circulating the wash water in the rinsing area or the washing tub during the rinsing process.

7. 7. The method for disinfecting laundry in a continuous washing machine according to claim 1, 2, 3, 4, 5 or 6, wherein a neutralizing agent for adjusting the pH of the wash water is supplied to a tank preceding the tank in the rinse area before the chlorine-containing water and carbon dioxide gas are supplied to the tank in the rinse area.

8. 8. The method for disinfecting laundry according to claim 7, which is used in a continuous washing machine equipped with a controller for controlling the supply amounts of the chlorine-containing water, carbon dioxide gas, and neutralizing agent, and a dehydrator installed near a laundry discharge outlet, The method for disinfecting laundry comprises detecting the chlorine concentration and pH value of the wastewater from the dehydrator, and correcting the amount of the chlorine-containing water, carbon dioxide gas or neutralizing agent to be supplied based on the detected values.

9. detecting the chlorine concentration and pH value of the wash water after the chlorine-containing water and carbon dioxide gas have been supplied; When the detected chlorine concentration value is lower than a lower limit value preset in the controller, the chlorine-containing water is additionally supplied, and when the detected chlorine concentration value is higher than an upper limit value preset in the controller, the amount of wash water corresponding to the difference between the detected value and the upper limit value is drained and the amount of new water corresponding to the difference is supplied; 9. A method for disinfecting laundry according to claim 1, wherein when the detected pH value is lower than a lower limit value preset in the controller, an amount of wash water corresponding to the difference between the lower limit value and the detected value is drained and new water of the same amount is supplied, and when the detected pH value is higher than an upper limit value preset in the controller, additional neutralizing agent is supplied.

10. In a commercial washing machine that disinfects laundry in the rinsing area or in the washing tub during the rinsing process with slightly acidic chlorine-containing water containing hypochlorous acid that has been slightly acidified with carbon dioxide, A high-temperature water tank for storing wastewater from the main wash area or main wash process of the washing machine; A carbon dioxide gas supply device connected to an inlet pipe to the washing tub in the rinsing area or the rinsing process, and a heat exchanger using hot water from the high-temperature water tank as a heat source; a solenoid valve for switching the inflow of water from an inlet pipe to the rinsing area or the rinsing step tank between a line that passes through the heat exchanger and a line that does not pass through the heat exchanger; The solenoid valve switches the inlet pipe upstream of the connection position of the carbon dioxide gas supply device.

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