JP4771201B2 - Production equipment for stabilized hypochlorous acid aqueous solution - Google Patents

Description

The present invention relates to an apparatus for producing a stabilized hypochlorous acid aqueous solution in which hypochlorous acid having excellent sterilizing power is stably present.

  In general, hypochlorous acid, which is known to have bactericidal activity, is produced as a colorless aqueous solution by passing chlorine through water. As shown in formula (1), it coexists with by-product hydrogen chloride. And can only exist.

Cl ₂ + H ₂ O → HClO + HCl (1)
In such a hypochlorous acid aqueous solution, the chlorine-oxygen bond is more easily broken than the oxygen-hydrogen bond, and thus it is a very weak acid. In order to improve the yield of hypochlorous acid, it is necessary to use toxic mercury chloride as a catalyst. Furthermore, since it is unstable, it is supposed to be stored in a cool and dark place, but in reality it is difficult to store, and it is necessary to use it immediately after generation, so it is not commercially available as a reagent.

  Furthermore, since the generation of hypochlorous acid is accompanied by the by-production of hydrogen chloride, as shown in the formulas (2) and (3), it is inevitably a strongly acidic aqueous solution after the generation. When the hydrogen ion exponent (pH value) of this strongly acidic aqueous solution is increased, the equilibrium state of the formula (3) that has been shifted to the original system (hypochlorous acid) side is shifted to the production system side according to Le Chatelier's law. Ionization into hydrogen ions and hypochlorite ions is further promoted, and decomposition reaction formula (4) is generated.

HCl → H ⁺ + Cl ⁻ (2)
HClO → H ⁺ + ClO ⁻ (3)
2HClO + ClO ⁻ → ClO ₃ + 2HCl (4)
That is, hypochlorous acid produced by the conventional method can exist only in a strongly acidic region in the presence of hydrogen chloride. And when such a hypochlorous acid aqueous solution coexisting with hydrogen chloride is used, generation of chlorine gas and generation of rust due to chlorine gas reaction occur, and a sterilizing effect in the alkaline region cannot be expected. Has been. One example is the fact that sterilization in the alkaline region is actually a problem.

  Therefore, in recent years, by adding sodium hypochlorite and dilute hydrochloric acid for adjusting pH value to water, a hypochlorous acid aqueous solution adjusted to a weakly acidic region where a large amount of hypochlorous acid is present is generated. Attempts have been made. For example, Patent Documents 1 and 2 disclose a method for producing a hypochlorous acid aqueous solution by adding sodium hypochlorite and hydrochloric acid to water.

JP 2001-321778 A JP-A-11-188083

  However, it has been difficult to stabilize the pH value of a conventional hypochlorous acid aqueous solution produced by adding sodium hypochlorite and dilute hydrochloric acid to water. When the pH value of the hypochlorous acid aqueous solution is high and it is in the alkaline region, there is not much hypochlorous acid, and it remains in the form of sodium hypochlorite, leading to a decrease in sterilizing power. It was. In addition, when the pH value is low and a strong acidic region is reached, there is a problem that chlorine gas is generated in the same manner as a hypochlorous acid aqueous solution generated by chlorine in water.

  Furthermore, even when the pH value of the hypochlorous acid aqueous solution at the time of production is adjusted to a weakly acidic region, there is a tendency that chlorine gas is generated over time and the effect is not exerted on sterilization in the alkaline region. It is done.

  The cause of such problems is that when the aqueous hypochlorous acid solution is produced, the sodium hypochlorite dilution reaction with water and the neutralization reaction between sodium hypochlorite and hydrochloric acid are performed accurately. In addition, even if hypochlorous acid is produced, it is in an unstable state coexisting with hydrogen chloride, and it is assumed that it is difficult to produce hypochlorous acid as a stable compound.

  Therefore, the hypochlorous acid aqueous solution produced by adding sodium hypochlorite and dilute hydrochloric acid to water has been studied in detail as sterilizing water, but the actual situation is that it has not yet been put to practical use. It is.

The present invention eliminates the above-mentioned problems, and provides a stabilized hypochlorous acid aqueous solution containing hypochlorous acid in a stable state that does not generate chlorine gas and exhibits excellent sterilizing power even in an alkaline region. An object is to provide a manufacturing apparatus for manufacturing .

In order to solve the above-mentioned problems, the apparatus for producing a stabilized hypochlorous acid aqueous solution of the present invention comprises a homogenizing dilution means for uniformly diluting sodium hypochlorite with water, and reacting the diluted water with diluted hydrochloric acid to adjust the pH. Stabilization reaction that adjusts the value to a weakly acidic region of 5.0 to 6.8 and produces a stabilized hypochlorous acid aqueous solution containing hypochlorous acid and sodium chloride without coexisting hydrogen chloride Means.

  Specifically, the homogenization dilution means includes a mixing dilution line for mixing water and sodium hypochlorite, and an expansion for naturally diffusing the diluted water after mixing by expanding the diameter of the mixing dilution pipe. A diameter dilution pipe, a bent dilution pipe that is provided downstream of the enlarged dilution pipe, generates a vortex by the flow of diluted water after diffusion, and promotes dilution, and more than the bent dilution pipe. A retention dilution pipe that is provided on the downstream side and retains the diluted water after the promotion of dilution.

And the said diameter expansion dilution channel and the said stay dilution channel are arrange | positioned along an up-down direction, those lower end parts are connected by the said curve dilution channel, and are continued substantially U-shaped as a whole, The mixed dilution pipe is connected to the upper end of the enlarged dilution pipe, and a drain pipe with a solenoid valve for discharging dilution water is connected to the bottom of the bent dilution pipe.

In addition, the stabilization reaction means includes a mixed reaction pipe for mixing the discharged diluted water and dilute hydrochloric acid, and a diameter expansion reaction for expanding the diameter of the mixed reaction pipe to naturally diffuse the mixed reaction water A curved reaction line that is provided downstream of the pipe and its enlarged diameter reaction pipe, generates a vortex by the flow of reaction water after diffusion, and promotes the reaction; and downstream of the curved reaction pipe And a residence reaction line for retaining the reaction water after the promotion of the reaction.

And the said diameter expansion reaction line and the said staying reaction line are arrange | positioned along an up-down direction, those lower end parts are connected by the said bending reaction line, and are continued substantially U-shaped as a whole, The mixed reaction pipe is connected to the upper end of the expanded reaction pipe, and a drain pipe with an electromagnetic valve for discharging generated water is connected to the bottom of the bent reaction pipe.

Although the stabilized hypochlorous acid aqueous solution produced by the production apparatus of the present invention contains hypochlorous acid similar to the conventional hypochlorous acid aqueous solution, it does not coexist with hydrogen chloride in its inclusion, The coexisting substances are decisively different from conventional hypochlorous acid aqueous solutions.

  For this reason, in the conventional hypochlorous acid aqueous solution, hypochlorous acid was in an unstable state due to the coexistence of hydrogen chloride, but in this stabilized hypochlorous acid aqueous solution, hypochlorous acid was stable. Therefore, no chlorine gas is generated during use, and excellent sterilizing power can be exhibited even in the alkaline region. Thereby, the stabilized hypochlorous acid aqueous solution excellent in sterilizing power can be circulated stably, and practical use can be achieved.

  In addition, a stable hypochlorous acid aqueous solution is produced by uniformly diluting sodium hypochlorite with water and reacting the diluted water with dilute hydrochloric acid in a stable manner to produce toxic chlorine gas or mercury chloride. It can be safely produced under mild conditions without using.

  Furthermore, in the manufacturing apparatus of the stabilized hypochlorous acid aqueous solution, the lower end portions of the enlarged diameter dilution pipe and the staying dilution pipe are connected with each other by bending the dilution pipe, and the lower end of the enlarged diameter reaction pipe and the staying reaction pipe By bending the parts and connecting them with a reaction pipe, dilution water and reaction water are gently accumulated in the whole pipe, and dilution and reaction can be performed stably over time. Accordingly, it is possible to reduce the apparatus size by shortening the pipe length of the pipe for stably carrying out the dilution water and the reaction water.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an apparatus for producing a stabilized hypochlorous acid aqueous solution according to an embodiment of the present invention.

  In FIG. 1, reference numeral (1) denotes a raw water supply pipe, and a first electromagnetic valve (2) for opening and closing the flow path and a flow meter (3) for measuring the raw water flow rate are provided in the middle.

  (6) is a sodium hypochlorite storage tank, (7) is a first injection pump, and sodium hypochlorite in the sodium hypochlorite storage tank (6) is supplied to the first injection pump (7 ) To the sodium hypochlorite supply line (8).

  The raw water supply pipe (1) and the sodium hypochlorite supply pipe (8) are joined via the first junction (9), and hypochlorite is added to the raw water at the first junction (9). Sodium acid is added to feed sodium hypochlorite to the homogenizing dilution means (10) for homogeneous dilution with raw water.

  The homogenization dilution means (10) includes a mixing dilution pipe (11) provided on the downstream side of the first merging section (9) and a diameter expansion dilution provided on the downstream side of the mixing dilution pipe (11). The pipe (12), the bending dilution pipe (13) provided downstream of the enlarged dilution pipe (12), and the stay dilution provided downstream of the bending dilution pipe (13) And a conduit (14).

  The enlarged dilution dilution line (12) and the stay dilution dilution line (14) are arranged along the vertical direction, and their lower ends are bent and connected by a dilution dilution line (13). ), (13) and (14) are generally continuous in a U-shape.

  These pipes (12), (14) and (13) are provided with a partition plate (16) along the vertical direction inside one dilution tank (15) along the vertical direction, and the partition plate (16) Is formed by forming a gap (17) for running water between the lower end of the dilution tank and the bottom of the dilution tank (15). Note that the pipes (12), (13), and (14) are not limited to being configured inside the single dilution tank (15) as described above, and for example, the pipes (12), (13), and (14) are piped. You may make it comprise with the pipe material for a road structure, and connect these pipe materials.

  Then, the mixed dilution pipe (11) is connected to the upper end portion of the enlarged diameter dilution pipe (12), and the drain pipe (18) for discharging dilution water is connected to the bottom of the bent dilution pipe (13). Yes. The drain pipe (18) is provided with a second electromagnetic valve (19) for opening and closing the channel. Further, the branch pipe (20) branched from the discharge pipe (18) is raised to a position higher than the upper ends of the enlarged dilution pipe (12) and the stay dilution pipe (14). An air vent pipe (21) extending from the upper end of the stay dilution pipe (14) is connected to the upper end of the pipe (20). The branch line (20) is provided with a third solenoid valve (22), and the air vent line (21) is provided with a fourth solenoid valve (23).

  (25) is a dilute hydrochloric acid storage tank, (26) is a second injection pump, and dilute hydrochloric acid in the dilute hydrochloric acid storage tank (25) is sent to the dilute hydrochloric acid supply line (27) by the second injection pump (26). It has become.

  The drain pipe (18) and the dilute hydrochloric acid supply pipe (27) are joined via the second junction (28), and diluted hydrochloric acid is added to the dilution water at the second junction (28) to stabilize It sends out to the stabilization reaction means (30) for producing | generating a hypochlorous acid aqueous solution.

  The stabilization reaction means (30) includes a mixed reaction pipe (31) provided on the downstream side of the second merging section (28), and a diameter expansion reaction provided on the downstream side of the mixed reaction pipe (31). Pipe (32), a bent reaction pipe (33) provided downstream of the expanded reaction pipe (32), and a staying reaction provided downstream of the bent reaction pipe (33) And a conduit (34).

  The expanded reaction pipe (32) and the residence reaction pipe (34) are arranged along the vertical direction, and their lower ends are bent and connected by the reaction pipe (33), and these pipes (32 ) (33) (34) are generally continuous in a U-shape.

  These pipes (32), (33) and (34) are provided with a partition plate (36) along the vertical direction inside one reaction tank (35) along the vertical direction, and the partition plate (36) A gap (37) for running water is formed between the lower end of the reactor and the bottom of the reaction tank (35). Note that the pipes (32), (33), and (34) are not limited to being configured in one reaction tank (35) as described above, and, for example, the pipes (32), (33), and (34) are piped. You may make it comprise with the pipe material for a road structure, and connect these pipe materials.

  The mixed reaction pipe (31) is connected to the upper end of the diameter-expanded reaction pipe (32), and the drain pipe (38) for discharging generated water is connected to the bottom of the bent reaction pipe (33). Yes. The drain pipe (38) is provided with a fifth electromagnetic valve (39) for opening and closing the channel. Further, the branch pipe (40) branched from the drain pipe (38) is raised to a position higher than the upper ends of the diameter-expanded reaction pipe (32) and the staying reaction pipe (34). An air vent pipe (41) extending from the upper end of the staying reaction pipe (34) is connected to the upper end of the pipe (40). A sixth solenoid valve (42) is provided in the branch pipe (40), and a seventh solenoid valve (43) is provided in the air vent pipe (41).

  (50) and (51) are first and second liquid level sensors which are provided in the sodium hypochlorite storage tank (6) and detect the height level of sodium hypochlorite in the tank (6). , (52) and (53) are third and fourth liquid level sensors which are provided in the dilute hydrochloric acid storage tank (25) and detect the height level of dilute hydrochloric acid in the tank (25). (54) (55) (56) is provided in the branch pipe (20), fifth to seventh liquid level sensors for detecting the height level of the dilution water in the branch pipe (20), 57, 58 and 59 are eighth to tenth liquid level sensors which are provided in the branch pipe (40) and detect the height level of the produced water in the branch pipe (40).

  These liquid level sensors (50) to (59) are connected to a control unit (61) composed of a microcomputer or the like via a signal line (60). Furthermore, the flow meter (3), the first to seventh solenoid valves (2), (19), (22), (23), (39), (42), (43), and the first and second infusion pumps (7), (26) Is connected to the control unit (61) via the signal line (60). The controller (61) detects the first and second infusion pumps (7) and (26) and the first to seventh electromagnetics according to the detection signals from the liquid level sensors (50) to (59) and the flow meter (3). The drive of the valves (2) (19) (22) (23) (39) (42) (43) is controlled.

  Next, production of stabilized hypochlorous acid using the production apparatus having the above-described configuration will be described.

  First, the first, third and fourth solenoid valves (2), (22) and (23) are opened, and the second, fifth to seventh solenoid valves (19), (39), (42) and (43) are closed. The raw water is sent out to the raw water supply pipe (1). At the same time, the first injection pump (7) is operated to send out sodium hypochlorite to the sodium hypochlorite supply line (8). The outflow amount of sodium hypochlorite at this time is controlled based on the raw water flow rate detected by the flow meter (3).

  And these raw | natural water and sodium hypochlorite flow into a mixing dilution pipe line (11) through a 1st confluence | merging part (9). In this mixed dilution pipe (11), the raw water and sodium hypochlorite are mixed to start dilution of the sodium hypochlorite with the raw water, and the running water in consideration of the viscosity and specific gravity of sodium hypochlorite. And flows into the enlarged dilution dilution pipe (12) having a diameter larger than that of the mixed dilution pipe (11).

  At this time, the expanded dilution pipe (12) has a negative pressure and is less likely to be pressurized than the mixed dilution pipe (11), so the diluted water after mixing gradually diffuses naturally. To do. That is, instead of compulsorily stirring with a stirrer or intentionally generating a pulsating flow using a baffle plate or the like, stirring is performed while leaving the natural flow of dilution water.

  The diluted dilution water flows in a waterfall shape and flows into the bending dilution pipe (13), and the vortex is generated at the bottom of the bending dilution pipe (13) due to the flow, and the dilution of the dilution water is promoted. .

  The dilution water after the promotion of dilution accumulates slowly and gently from the lower end to the upper end of the stay dilution pipe (14) and stays in the stay dilution pipe (14), resulting in a sodium hypochlorite concentration gradient. The dilution process is completed in a homogenized state with almost no slag.

  At this time, the dilution water also stays in the enlarged diameter dilution pipe (12). Further, when diluted water flows from the drain pipe (18) into the branch pipe (20) and this diluted water is detected by the fifth liquid level sensor (54), the controller (61) causes the pipe (12 ) (13) It is determined that dilution water has accumulated in (14), the first electromagnetic valve (2) is closed, and the supply of raw water is stopped.

  Note that the time (Δt) required for the dilution reaction from the start of dilution to the completion of dilution is important for realizing homogenization of dilution, and appropriately adjusts the inner diameter and length of each pipe line according to the dilution concentration. It is set by that.

  In this homogenization dilution step, the sodium hypochlorite is homogeneously diluted with raw water by introducing the dilution water in a state close to a natural flow to cause the dilution reaction.

  When the homogenization dilution process is completed, the second, third, fourth, sixth, and seventh solenoid valves (19), (22), (23), (42), and (43) are opened, and the first and first solenoid valves are opened. 5 With the solenoid valves (2) and (39) closed, diluting water is sent out from the drain pipe (18). At the same time, the second injection pump (26) is operated to send pH-adjusted dilute hydrochloric acid to the dilute hydrochloric acid supply line (27). At this time, the control unit (61) controls the second injection pump (26), so that a predetermined amount of dilute hydrochloric acid set in advance according to the amount and concentration of the diluted water flows out.

  These diluted water and dilute hydrochloric acid flow into the mixed reaction pipe (31) through the second junction (28). In the mixed reaction line (31), the diluted water and dilute hydrochloric acid are mixed to start these reactions. The mixed reaction water flows into the expanded reaction pipe (32) having a diameter larger than that of the mixed reaction pipe (31).

  At this time, the expanded reaction pipe (32) has a negative pressure and is less likely to be pressurized than the mixed reaction pipe (31), so the reaction water after mixing gradually diffuses naturally. To do. That is, instead of forcibly stirring with a stirrer or intentionally generating a pulsating flow using a baffle plate or the like, stirring is performed instead of the natural flow of reaction water.

  The reaction water after diffusion flows in a waterfall shape and flows into the bent reaction pipe (33), and the vortex is generated at the bottom of the bent reaction pipe (33) by the flow, and the reaction of the reaction water is promoted. .

  After the reaction is promoted, the reaction water slowly and gently accumulates from the lower end to the upper end of the staying reaction pipe (34) and stays in the staying reaction pipe (34). The reaction process is completed by reacting in a stable state.

  At this time, the reaction water also stays in the expanded diameter reaction pipe (32). Further, the reaction water flows from the drain pipe (38) into the branch pipe (40), and the eighth liquid level sensor (57) detects this reaction water, or the seventh liquid level sensor ( When 56) detects the discharge of the dilution water in the branch pipe (20), the control unit (61) determines that the reaction water has accumulated in the pipes (32), (33) and (34), and the second The fourth solenoid valves (19), (22) and (23) are closed to prepare for the next dilution step.

  The time (Δt ′) required from the start of the reaction to the completion of the reaction is important for realizing the stabilization of the reaction, and the pipe inner diameter and the pipe length of each pipe line are appropriately set according to the set pH value of the produced water. It is set by adjusting.

  In this stabilization reaction step, diluting water and dilute hydrochloric acid are guided in a state close to a natural flow, and these reactions are performed stably, so that the pH is adjusted to a weakly acidic region of 6.5, and chloride is added. A 50 ppm stabilized hypochlorous acid aqueous solution containing hypochlorous acid and sodium chloride is produced without coexisting hydrogen. In addition, the pH value of the stabilized hypochlorous acid aqueous solution can be adjusted to a weakly acidic region of 5.0 to 6.8 by appropriately adjusting the amount of diluted hydrochloric acid to be reacted with the dilution water.

  The generated stabilized hypochlorous acid aqueous solution is taken out from the drain pipe (38) by opening the fifth solenoid valve (39). By repeating the above dilution step and reaction step, a stabilized hypochlorous acid aqueous solution can be stably produced although it is a discontinuous formation.

  In addition, the continuous production | generation which performs a dilution process and a reaction process continuously by control by a control part (61) is also possible. In this case, the sixth liquid level sensor (55) and the ninth liquid level sensor (58) are used as the liquid level sensors.

  As a result of iron rusting test using the stabilized hypochlorous acid aqueous solution generated as described above, the conventional weak acidic aqueous solution (in the weak acidic region) generated by the conventional mixing method and electrolysis method. Compared with the hypochlorous acid aqueous solution which was said to have been adjusted, rusting was clearly suppressed.

  In addition, in the rust test of the joint made of gunmetal attached to the device, in the above-mentioned stabilized hypochlorous acid aqueous solution, there was no patina, the inner surface was black and an oxide film was formed, In the above-described conventional one, generation of patina and rust was observed in the apparatus.

  As is clear from these test results, rusting can be reliably suppressed by using a stabilized hypochlorous acid aqueous solution, so that chlorine that causes rusting when using a stabilized hypochlorous acid aqueous solution is used. It can be seen that no gas is generated, and therefore it can be assumed that hypochlorous acid is stably present as a compound in the stabilized hypochlorous acid aqueous solution without coexisting hydrogen chloride.

  In addition, by injecting the above-mentioned stabilized hypochlorous acid aqueous solution (200 ppm, pH value 6.5) into an alkaline hot spring having a pH value of 9.1, various types of sterilization lamps, chlorine disinfectants, and the like are used. It became possible to sterilize Legionella, which was impossible to achieve with sterilization methods. In this case, 1 L of stabilized hypochlorous acid aqueous solution was injected for 1000 L of hot spring water.

  As is clear from this result, it was found that the sterilizing power of hypochlorous acid in the stabilized hypochlorous acid aqueous solution works effectively even in an alkaline region such as an alkaline hot spring, and thus the stabilized hypochlorous acid aqueous solution. It can be presumed that hypochlorous acid exists stably as a compound without coexisting hydrogen chloride therein.

  Furthermore, by using a pH meter to determine whether the pH value of the stabilized hypochlorous acid aqueous solution is stable over time, hypochlorous acid present in the stabilized hypochlorous acid aqueous solution is also measured. It is possible to demonstrate that the acid is stable. This is because conventional hypochlorous acid exists in the presence of hydrogen chloride, so that the residual chlorine concentration decreases with time and the pH value advances to the acidic side.

  The present invention is not limited to the above embodiment, and it is needless to say that many modifications and changes can be made to the above embodiment within the scope of the present invention.

It is the schematic of the manufacturing apparatus of the stabilized hypochlorous acid aqueous solution which concerns on one Embodiment of this invention.

Explanation of symbols

(10) Homogenization dilution method
(11) Mixed dilution pipe
(12) Expansion dilution pipe
(13) Bending dilution pipeline
(14) Residence dilution pipeline
(18) (38) Drain pipe with solenoid valve
(30) Stabilization reaction means
(31) Mixed reaction line
(32) Expanded reaction pipeline
(33) Curved reaction pipeline
(34) Residence reaction line

Claims (1)

Homogenizing dilution means for homogeneously diluting sodium hypochlorite with water and dilute hydrochloric acid to react with the diluted water to adjust the pH value to a weakly acidic region of 5.0 to 6.8 and to coexist with hydrogen chloride And a stabilizing reaction means for producing a stabilized hypochlorous acid aqueous solution containing hypochlorous acid and sodium chloride without any
The homogenization dilution means includes a mixing dilution pipe for mixing water and sodium hypochlorite, and a diameter expansion dilution pipe for expanding the diameter of the mixed dilution pipe and allowing the diluted water after mixing to diffuse naturally. And a bent dilution pipe that is provided downstream of the enlarged dilution dilution pipe and generates a vortex by the flow of diluted water after diffusion to promote dilution, and is provided downstream of the bent dilution pipe. And a retention dilution line for retaining the diluted water after the promotion of dilution,
The enlarged dilution pipe and the stay dilution pipe are arranged along the vertical direction, and their lower ends are connected to each other by the bent dilution pipe and are continuously continued in a substantially U shape. The mixed dilution pipe is connected to the upper end of the dilution pipe, and the drain pipe with a solenoid valve for discharging dilution water is connected to the bottom of the bent dilution pipe,
The stabilizing reaction means includes a mixed reaction line for mixing the discharged diluted water and dilute hydrochloric acid, and a diameter-expanded reaction line for expanding the diameter of the mixed reaction line and allowing the reaction water after mixing to diffuse naturally. And a bent reaction pipe that is provided downstream of the expanded reaction pipe to generate a vortex by the flow of reaction water after diffusion and promotes the reaction, and is provided downstream of the bent reaction pipe. And a retention reaction line for retaining the reaction water after promoting the reaction,
The expanded reaction pipe and the staying reaction pipe are arranged along the vertical direction, and their lower ends are connected to each other by the bent reaction pipe and are continuously continued in a substantially U shape, The stabilization reaction line is characterized in that the mixed reaction line is connected to the upper end of the reaction line, and a drain line with a solenoid valve for discharging generated water is connected to the bottom of the bent reaction line. Chloric acid aqueous solution manufacturing equipment.

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