Operation method of a water circulation system

Abstract

This invention provides an operating method for a water circulation system that makes it easier to prevent blockages in the disinfectant supply pipes that supply disinfectants to the circulating water system. [Solution] A method for operating a water circulation device 1 comprising a circulating water system 3 through which water circulates, a disinfectant storage tank 4 for storing a solution containing a disinfectant, and a disinfectant supply pipe 5 connecting the disinfectant storage tank 4 and the circulating water system 3, the method comprising supplying a solution containing a disinfectant and a dispersant from the disinfectant storage tank 4 to the circulating water system 3 via the disinfectant supply pipe 5.

Description

Technical Field

[0001] The present invention relates to a method for operating a water circulation device.

Background Art

[0002] In a water circulation device such as a circulating bath facility or a cooling water circulation device, a bactericide may be injected into the circulating water. The addition of the bactericide to the circulating water is typically performed using an injection device that continuously or intermittently injects the bactericide into the circulating water system. This type of injection device includes a nozzle for injecting the bactericide into the circulating water system. Since the injection amount of the bactericide is small relative to the flow rate of the circulating water, a nozzle with a relatively small diameter is often used for the injection device.

[0003] Due to the small diameter of the nozzle, clogging of the nozzle tends to be a problem. For example, metal ions such as calcium ions contained in the circulating water may form salts with anions such as carbonate ions to produce poorly soluble precipitates, and these precipitates may cause clogging of the nozzle. When such clogging occurs, the injection of the bactericide cannot be properly performed, and there is a risk that the sanitary condition of the water circulation device will deteriorate.

[0004] In view of this clogging problem, Utility Model Registration No. 3148835 (Patent Document 1) discloses a chemical injection mixer provided with a chemical injection check valve on a side wall of a transparent chemical injection mixer body that can be visually observed from the outside, and a maintenance branch pipe with a removable closing flange is attached to the side wall facing the chemical injection check valve. According to the invention described in Patent Document 1, it is possible to detect clogging of the chemical injection check valve at an early stage and easily perform the work of eliminating such clogging.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The invention described in Patent Document 1 facilitates the detection and resolution of blockages, but does not prevent blockages.

[0007] Therefore, it is desirable to realize an operating method for a water circulation system that makes it easier to prevent blockages in the disinfectant supply pipes that supply disinfectants to the circulating water system. [Means for solving the problem]

[0008] The method for operating a water circulation device according to the present invention comprises a circulating water system through which water circulates, a disinfectant storage tank for storing a solution containing a disinfectant, and a disinfectant supply pipe connecting the disinfectant storage tank and the circulating water system, and is characterized by comprising supplying a solution containing the disinfectant and a dispersant from the disinfectant storage tank to the circulating water system via the disinfectant supply pipe.

[0009] With this configuration, the action of the dispersant prevents the adhesion of precipitates, making it easier to prevent blockages in the disinfectant supply pipe.

[0010] Preferred embodiments of the present invention will be described below. However, the scope of the present invention is not limited by the examples of preferred embodiments described below.

[0011] In one embodiment of the operating method for the water circulation device according to the present invention, it is preferable that the dispersant contains a phosphinocarboxylic acid copolymer.

[0012] This configuration makes it particularly easy to prevent blockages in the disinfectant supply pipe.

[0013] In one embodiment, the operating method of the water circulation device according to the present invention preferably includes at least one compound selected from the group consisting of sodium hypochlorite, stabilized sodium hypochlorite, and stabilized sodium hypobromite as the disinfectant.

[0014] According to this configuration, a sterilization effect can be easily obtained.

[0015] As one aspect, the operation method of the water circulation device according to the present invention preferably has a pH of the solution containing the bactericide and the dispersant of 12 or more and 14 or less.

[0016] According to this configuration, the decomposition of the bactericide in the solution stored in the bactericide storage tank is suppressed.

[0017] As one aspect, the operation method of the water circulation device according to the present invention preferably has an inner diameter of the bactericide supply pipe at the connection portion between the bactericide supply pipe and the circulating water system of 8 mm or more and 15 mm or less.

[0018] According to this configuration, it is easy to control the flow rate of the bactericide solution.

[0019] As one aspect, the operation method of the water circulation device according to the present invention preferably includes hot spring water in the water circulating through the circulating water system.

[0020] When the circulating water contains hot spring water, precipitates are particularly likely to occur, so the benefit of applying the present invention is particularly great.

[0021] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments described with reference to the drawings.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing the configuration of a circulating bath facility according to an embodiment.

Mode for Carrying Out the Invention

[0023] An embodiment of the operation method of the water circulation device according to the present invention will be described with reference to the drawings. Hereinafter, an example in which the operation method according to the present invention is applied as the operation method of a circulating bath facility 1 (an example of a water circulation device) schematically illustrated in FIG. 1 will be described. <00

[0024] 〔Configuration of the Circulating Bath Facility〕 The circulating bath facility 1 according to this embodiment includes a bathing tub 2, a circulation pipe 3, a disinfectant storage tank 4, a disinfectant supply pipe 5, a hair collector 6, a filtration pump 7, and a filtration device 8 (Fig. 1). In the circulating bath facility 1, the bathing tub 2, the circulation pipe 3, the hair collector 6, the filtration pump 7, and the filtration device 8 form a circulation water system 10, and the water flowing out of the bathing tub 2 is urged by the filtration pump 7 and supplied back to the bathing tub 2. The circulation pipe 3 is a pipe that serves as a path through which water circulates. Hereinafter, the water circulating in the circulation water system 10 may be referred to as circulation water. Note that the hair collector 6, the filtration pump 7, and the filtration device 8 are each known devices generally used in a circulating bath facility, and their descriptions will be omitted hereinafter.

[0025] The bathing tub 2 is a water tank in which a user takes a bath. The bathing tub 2 is not limited as long as it is a water tank used for a person to take a bath, and can be, for example, a bathtub or a pool. As an example, in the bathing tub 2, the circulation pipe 3 is connected to an inlet 21 provided at the lower part in the depth direction of the side wall, and the water filtered by the filtration device 8 is supplied therefrom. Further, the circulation pipe 3 is connected to an outlet 22 provided at the lower part in the depth direction of the side wall opposite to the side wall where the inlet 21 is provided, and guides the water flowing out of the bathing tub 2 to the hair collector 6. Note that an overflow groove (not shown) may be provided in the bathing tub 2.

[0026] The circulation pipe 3 is a pipe that serves as a path through which water circulates in the circulating bath facility 1. In this embodiment, the circulation pipe 3 has a main path 31 that passes from the outlet 22 of the bathing tub 2 through the hair collector 6, the filtration pump 7, and the filtration device 8 in this order and reaches the inlet 21 of the bathing tub 2. Further, the main path 31 has a connection point 32 to which the disinfectant supply pipe 5 is connected between the filtration pump 7 and the filtration device 8. At the connection point 32, a solution containing a disinfectant is added to the circulation water.

[0027] The disinfectant storage tank 4 is a storage tank for storing a solution containing a disinfectant (hereinafter referred to as the disinfectant solution). The mechanical configuration (dimensions, shape, material, etc.) of the disinfectant storage tank 4 is not limited, as long as at least the inner surface is not corroded by the disinfectant. The disinfectant solution contains a disinfectant and a dispersant. The disinfectant storage tank 4 is connected to the circulation pipe 3 (main route 31) via the disinfectant supply pipe 5. The disinfectant solution is supplied from the disinfectant storage tank 4 to the circulation pipe 3 (main route 31) via the disinfectant supply pipe 5. Since the amount of disinfectant solution added is very small compared to the flow rate of the circulating water, the disinfectant supply pipe 5 is narrower than the circulation pipe 3.

[0028] The disinfectant solution may be prepared in the disinfectant storage tank 4 or elsewhere. In the former case, for example, the disinfectant solution is prepared by adding a solution containing a disinfectant (such as a commercially available disinfectant product) and a dispersant to the disinfectant storage tank 4 and thoroughly mixing them. Therefore, the disinfectant storage tank 4 may have a stirring device or the like.

[0029] The disinfectant is not particularly limited as long as it is a disinfectant used in a bathing facility intended for human bathing. Such a disinfectant may be, but is not limited to, halogenated disinfectants such as sodium hypochlorite, stabilized sodium hypochlorite, and stabilized sodium hypobromite. Preferably, the disinfectant contains at least one compound selected from the group consisting of sodium hypochlorite, stabilized sodium hypochlorite, and stabilized sodium hypobromite. The disinfectant may be one compound or multiple compounds.

[0030] The dispersant is not particularly limited as long as it is a dispersant that can be used in bathing facilities intended for human bathing. Here, "usable" means that it does not have adverse effects on the human body, or the possibility of adverse effects is at an acceptable level. Examples of dispersants that satisfy this requirement include, but are not limited to, organic polymers such as polyacrylic acid, acrylic acid copolymers, polymaleic acid, maleic acid copolymers, maleic anhydride copolymers, and terpolymers or salts thereof having carboxyl groups, sulfo groups, and nonionic groups, as well as organic acids and their salts (sodium salts, potassium salts, etc.) such as 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, hydroxyphosphonoacetic acid, phosphinocarboxylic acid copolymers, and hexametaphosphate. The dispersant preferably contains a phosphinocarboxylic acid copolymer. The dispersant may be one compound or multiple compounds.

[0031] The disinfectant solution preferably has a pH of 12 to 14. When the pH of the disinfectant solution is within the above range, the decomposition of the disinfectant in the disinfectant solution stored in the disinfectant storage tank 4 is suppressed.

[0032] The disinfectant supply pipe 5 is a pipe that connects the disinfectant storage tank 4 and the circulation pipe 3. The disinfectant supply pipe 5 is equipped with a control pump 51 that controls the flow rate of the disinfectant solution. The mechanical configuration (dimensions, shape, material, etc.) of the disinfectant supply pipe 5 is not limited as long as at least the inner surface is not corroded by the disinfectant, but it is preferable that the inner diameter at least at the connection point 32 is 8 mm or more and 15 mm or less. Having the inner diameter of the disinfectant supply pipe 5 at the connection point 32 within the above range is preferable because it makes it easier to control the flow rate of the disinfectant solution.

[0033] [Driving method configuration] Next, an embodiment of the operating method for the circulating bathing facility 1 according to this embodiment will be described. The operating method according to this embodiment includes adding a disinfectant and a dispersant to the disinfectant storage tank 4, and supplying the disinfectant solution from the disinfectant storage tank 4 to the circulation pipe 3 via the disinfectant supply pipe 5.

[0034] A disinfectant solution can be prepared in the disinfectant storage tank 4 by adding a disinfectant and a dispersant to the disinfectant storage tank 4. As described above, a disinfectant solution is obtained by adding a solution containing a disinfectant (such as a commercially available disinfectant product) and a dispersant to the disinfectant storage tank 4 and thoroughly mixing them. There is no restriction on adding substances other than the disinfectant and dispersant to the disinfectant storage tank 4; for example, a diluent such as water may be added.

[0035] By supplying a disinfectant solution from the disinfectant storage tank 4 to the circulation pipe 3 via the disinfectant supply pipe 5, the water used for bathing in the bathtub 2 can be disinfected. This allows for the maintenance of water quality suitable for bathing.

[0036] Conventionally, in circulating bathing facilities, metal ions such as calcium ions in the water can form salts with anions such as carbonate ions, resulting in poorly soluble precipitates. These precipitates can cause problems such as blockage of the outlet (i.e., connection point 32) of the disinfectant supply pipe 5. This is because the disinfectant supply pipe 5 is narrower than the circulation pipe 3. In this embodiment, the dispersant contained in the disinfectant solution plays a role in dispersing the precipitates in the water. This suppresses problems such as blockage of the connection point 32 due to the adhesion of precipitates to pipes, etc.

[0037] Furthermore, when the circulating water is hot spring water, precipitates are particularly likely to form, and their growth is significant. The benefits of applying the present invention are especially great when the circulating water is hot spring water. As shown in the examples described later, the present invention also demonstrated an effect of suppressing precipitate growth when the circulating water is hot spring water.

[0038] [Other Embodiments] Finally, other embodiments of the operating method for the water circulation device according to the present invention will be described. Note that the configurations disclosed in each of the following embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise.

[0039] In the above embodiment, an example was described in which the operating method according to the present invention is applied to the operating method of a circulating bathing facility 1. However, the water circulation device to which the operating method according to the present invention is applied is not limited to a circulating bathing facility, but may also be, for example, a swimming facility such as a swimming pool, a cooling water circulation device used in an air conditioning system, a water circulation device that circulates well water, a water circulation device that supplies medical water, and so on.

[0040] With regard to other configurations, the embodiments disclosed herein are illustrative in all respects, and it should be understood that the scope of the present invention is not limited thereto. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the invention. Therefore, other embodiments modified without departing from the spirit of the invention are naturally included within the scope of the present invention. [Examples]

[0041] The present invention will be further described below with reference to examples. However, the following examples are not limiting to the present invention.

[0042] (1) Relationship between pH and stability of disinfectant solution The following method was used to evaluate the differences in stability of disinfectant solutions due to differences in pH.

[0043] (Preparation Example 1) An aqueous solution containing 96% by mass of sodium hypochlorite and 2% by mass of phosphinocarboxylic acid copolymer was prepared by mixing sodium hypochlorite, an aqueous solution of phosphinocarboxylic acid copolymer (pH 5.1), and water. Sodium hypochlorite is an example of a disinfectant, and phosphinocarboxylic acid copolymer is an example of a dispersant. The halogen concentration X0 of the prepared aqueous solution was measured by the DPD method.

[0044] (Preparation Example 2) A phosphinocarboxylic acid copolymer aqueous solution (pH 5.1) was prepared by adding sodium hydroxide to adjust the pH to 9.2. Aqueous solutions were then prepared in the same manner as in Preparation Example 1, except that the pH-adjusted phosphinocarboxylic acid copolymer aqueous solution was used. The halogen concentration X0 of the prepared aqueous solutions was measured by the DPD method.

[0045] (Preparation Examples 3-6) The tests were conducted in the same manner as in Preparation Example 2, except that the pH of the phosphinocarboxylic acid copolymer aqueous solutions after pH adjustment was set to 10.5, 11.2, 13.1, and 13.7, respectively.

[0046] (Evaluation of residual sodium hypochlorite) Each aqueous solution from Preparation Examples 1 to 6 was left to stand in a room at room temperature (25°C) for 60 days. The halogen concentration X1 of each aqueous solution after standing was measured by the DPD method, and the residual sodium hypochlorite ((X1 / X0) × 100) in each aqueous solution was calculated. The residual rates for each aqueous solution are shown in Table 1. A tendency was observed for higher residual rates to occur with increasing pH.

[0047] Table 1: Relationship between pH of phosphinocarboxylic acid copolymer aqueous solution and residual sodium hypochlorite content. [Table 1]

[0048] (2) Practical examination This study compared the operation of two circulating bathing facilities located in hot spring resorts in Japan, comparing the operation of a facility implementing the present invention with that of a facility not implementing the present invention (conventional operation). Sodium hypochlorite was used as a disinfectant, and a phosphinocarboxylic acid copolymer was used as a dispersant. For explanatory purposes, parts of the configuration of each circulating bathing facility that are common to the above embodiment are denoted with the same reference numerals as in the above embodiment. Note that the two circulating bathing facilities are located in different hot spring resorts.

[0049] In the first circulating bathing facility, under conventional operation without implementing the present invention, cleaning was required approximately every two days to avoid blockage of the connection point 32 due to precipitates. Under operation with the present invention, cleaning of the connection point 32 was not required for at least six months. In the first circulating bathing facility, the inner diameter of the disinfectant supply pipe 5 at the connection point 32 was 10 mm.

[0050] In the second circulating bathing facility, under conventional operation without implementing the present invention, cleaning was required approximately once every seven days to avoid blockage of the connection point 32 due to precipitates. Under operation with the present invention, cleaning of the connection point 32 was not required for at least two months. Subsequently, when the implementation of the present invention was discontinued and the conventional operation without the present invention was returned, blockage of the connection point 32 was observed after seven days. In the second circulating bathing facility, the inner diameter of the disinfectant supply pipe 5 at the connection point 32 was 13 mm. [Industrial applicability]

[0051] This invention can be applied to the operation of circulating bath facilities, cooling water circulation systems, and the like. [Explanation of symbols]

[0052] 1: Recirculating bathing facility 2: Entering the bathtub 21:Inlet 22: Outlet 3: Circulation tube 31: Main Route 32: Connection point 4: Disinfectant storage tank 5: Disinfectant supply pipe 51: Control pump 6: Hair collector 7: Filtration pump 8: Filtration device 10: Circulating water system

Claims

1. A method for operating a water circulation system comprising a circulating water system through which water circulates, a disinfectant storage tank for storing a solution containing a disinfectant, and a disinfectant supply pipe connecting the disinfectant storage tank and the circulating water system, An operating method comprising supplying a solution containing the disinfectant and a dispersant from the disinfectant storage tank to the circulating water system via the disinfectant supply pipe.

2. The operating method according to claim 1, wherein the dispersant comprises a phosphinocarboxylic acid copolymer.

3. The operating method according to claim 1, wherein the disinfectant comprises at least one compound selected from the group consisting of sodium hypochlorite, stabilized sodium hypochlorite, and stabilized sodium hypobromite.

4. The operating method according to claim 1, wherein the pH of the solution containing the disinfectant and the dispersant is 12 or higher and 14 or lower.

5. The operating method according to claim 1, wherein the inner diameter of the disinfectant supply pipe at the connection portion between the disinfectant supply pipe and the circulating water system is 8 mm or more and 15 mm or less.

6. The operating method according to claim 1, comprising adding the disinfectant and the dispersant to the disinfectant storage tank.

7. The operating method according to any one of claims 1 to 6, wherein the water circulating in the circulating water system includes hot spring water.

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