Ozone water generating device and ozone water generating method

Abstract

To reduce bubbles remaining in a pump of an ozone water generating device, thereby suppressing idling of the pump and stabilizing operation of the ozone water generating device at startup. In an ozone water generating device (1), a tank (2) stores water. A pump (3) is disposed below the tank (2). An ejector (4) is disposed vertically between the tank (2) and the pump (3) and injects ozone gas drawn from the outside into the water introduced from the tank (2), thereby discharging the ozone water. A return line (5) returns the discharged ozone water to the tank (2).

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for producing ozone water using high-concentration ozone gas. [Background technology]

[0002] Examples of ozone water generating devices that generate ozone water by dissolving ozone gas in water include ejector-type devices as disclosed in Patent Documents 1 and 2.

[0003] In an ejector-type ozone water generator, if negative pressure occurs in the ozone generator connected to the suction port of the ejector, the ozone gas generation capacity decreases and the probability of malfunctioning of the ozone generator increases. Therefore, the ozone water generator of Patent Document 1 provides an orifice between the ozone generator and the ejector to maintain a positive pressure in the ozone gas generation section of the ozone generator, thereby supplying ozone gas to the ejector under the same pressure.

[0004] The ozonated water supply system of Patent Document 2 includes an ozonated water supply line, an ozonated water circulation line, an ozone concentration sensor, and a controller for the ozone concentration generated by the ozone generator, and controls the ozone concentration to eliminate fluctuations in the ozone concentration due to the release of ozonated water into the supply line, etc. Ozone gas, which is the raw material for ozonated water, is generated by an electric discharge ozonizer that uses oxygen as the main raw material and generates ozone gas by electric discharge, and the supply pressure is above atmospheric pressure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4746515 [Patent Document 2] Patent No. 7041466 [Patent Document 3] Patent No. 4186551 [Patent Document 4] Patent No. 4118185 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned conventional technology, ozone water is produced by mixing ozone gas and water using a gas-liquid mixing device such as an ejector. At this time, the supply pressure of the ozone gas is considered to be positive.

[0007] On the other hand, some ozone gas generating devices (ozonizers) maintain ozone gas at negative pressure within the device in order to suppress the self-decomposition of highly concentrated ozone gas, etc. However, even with such ozonizers, it is possible to generate ozone water using a conventional ejector.

[0008] However, if air gets mixed into the system, the pump in the ozone water circulation line will run idle, reducing the circulation flow rate, and the suction pressure of the ejector will decrease, making operation unstable and leading to a decrease in the concentration of ozone water.

[0009] In view of the above circumstances, the present invention aims to reduce the amount of air bubbles remaining in the pump of an ozone water generation apparatus, thereby suppressing idling of the pump and stabilizing the operation of the ozone water generation apparatus at startup. [Means for solving the problem]

[0010] Therefore, one aspect of the present invention is an ozone water generating device that includes a tank for storing water, a pump arranged below the tank, an ejector arranged vertically between the tank and the pump for injecting ozone gas sucked from the outside into the water introduced from the tank and discharging ozone water, and a return line that can return the discharged ozone water to the tank.

[0011] In one aspect of the present invention, in the ozone water generation apparatus, a plurality of the ejectors are arranged in parallel.

[0012] In one aspect of the present invention, in the ozone water generation apparatus, the ejectors are arranged at equal intervals on a concentric circle centered on the suction center of the pump.

[0013] In one aspect of the present invention, in the ozone water generating apparatus, the tank is provided with an exhaust line for discharging gas inside the tank.

[0014] In one aspect of the present invention, in the ozone water generating apparatus, the exhaust line is provided with an ozone decomposer that decomposes ozone contained in the gas discharged from the tank.

[0015] One aspect of the present invention is a method for generating ozone water using an ozone water generating apparatus having a tank for storing water, a pump arranged below the tank, and an ejector arranged vertically between the tank and the pump, the method comprising the steps of injecting ozone gas sucked from the outside into the water introduced from the tank into the ejector, and discharging the ozone water from the ejector, and returning the discharged ozone water to the tank. [Effects of the Invention]

[0016] According to the present invention, the amount of bubbles remaining in the pump of the ozone water generation apparatus is reduced and the idling of the pump is suppressed, so that the operation of the ozone water generation apparatus at start-up is stabilized. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing the configuration of an ozone water generating apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram showing the configuration of an ozone water generating apparatus according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a plan view showing the arrangement of ejectors according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] [Embodiment 1] An ozone water generating apparatus 1 according to a first embodiment of the present invention shown in FIG. 1 includes a tank 2, a pump 3, an ejector 4, and a return line 5.

[0020] Tank 2 stores water. Tank 2 is equipped with a water supply line 21, a drain line 22, an exhaust line 23, and gas supply lines 24 and 25. Gas supply line 24 supplies gas to the gas phase in tank 2. Gas supply line 25 supplies gas to the liquid phase in tank 2. Water supply line 21, drain line 22, exhaust line 23, and gas supply lines 24 and 25 are each equipped with flow control valves V1, V2, V5, V6, and V7 that can arbitrarily control the flow rate of the fluid.

[0021] The pump 3 is disposed below the tank 2. A suction line 6 is connected to the suction side of the pump 3, to which the ozonated water discharged from the ejector 4 is supplied. A discharge line 7 is connected to the discharge side of the pump 3, to which the ozonated water is supplied to an ozonated water utilization system (not shown). The discharge line 7 is equipped with a concentration meter 71 and a flow control valve V4.

[0022] The ejector 4 is disposed vertically between the tank 2 and the pump 3, and injects ozone gas sucked from outside into the water introduced from the tank 2, thereby discharging ozone water. A known ejector, such as that described in Patent Documents 3 and 4, is applicable as the ejector 4. A drainage line 22 extending from the tank 2 is connected to the inlet side of the ejector 4. An injection line 41, through which ozone gas is supplied from an ozone gas generator (not shown), is connected to the injection side of the ejector 4. A flow control valve V3 is provided on the injection line 41. A suction line 6, which is connected to the suction side of the pump 3, is connected to the outlet side of the ejector 4.

[0023] The return line 5 allows the discharged ozone water to be returned to the tank 2. The return line 5 is provided with a flow meter 51.

[0024] The exhaust line 23 is equipped with a pressure gauge 26 and an ozone decomposer 8. The ozone decomposer 8 decomposes ozone contained in the gas discharged from the tank 2. The ozone decomposer 8 employs a well-known ozone decomposition method, such as a thermal decomposition method, an activated carbon method, or an ultraviolet method.

[0025] An example of the operation of the ozone water production apparatus 1 of the first embodiment will be described with reference to FIG.

[0026] First, the flow control valves V1 and V2 are set to open, and the flow control valves V3, V4, V5, V6, and V7 are set to close, and water is introduced into the tank 2 through the water supply line 21. Next, the drain line 22, the ejector 4, the suction line 6, the pump 3, the discharge line 7, and the return line 5 are filled with water, and further, a predetermined amount of water is stored in the tank 2.

[0027] Next, the flow control valve V1 is closed, the pump 3 is started, and the water is circulated and supplied to the tank 2 via the drain line 22, the ejector 4, the suction line 6, the discharge line 7, and the return line 5. Here, the flow control valve V6 is opened as appropriate, and an inert gas (e.g., nitrogen gas) is supplied to the gas phase in the tank 2 via the gas supply line 24, thereby appropriately adjusting the internal pressure of the tank 2. Furthermore, when the internal pressure is to be reduced, the flow control valve V5 is opened as appropriate, and the gas in the tank 2 is discharged via the exhaust line 23. Furthermore, the flow control valve V7 is opened as appropriate, and carbon dioxide gas (CO2) is supplied to the water in the tank 2 via the gas supply line 25, thereby appropriately adjusting the water to the acidic side, thereby preparing water into which ozone is easily dissolved.

[0028] Thereafter, when the suction pressure of the ejector 4 reaches a pressure at which the ozone gas in the injection line 41 can be sucked into the ejector 4, the flow control valve V3 is set to open and the ozone gas is injected into the water in the ejector 4. Then, the ozone water discharged from the ejector 4 is supplied to the pump 3 via the suction line 6. The ozone water discharged from the pump 3 is returned to the tank 2 via the discharge line 7 and the return line 5.

[0029] Next, the ozone concentration of the ozonated water circulated and supplied to tank 2 is adjusted to a desired concentration (e.g., an ozone concentration of 200 mg / L or more) by automatically adjusting the openings of flow control valves V2 and V3 based on the ozone concentration and flow rate detected by concentration meter 71 and flow meter 51. Then, flow control valve V4 is set to open, and the ozonated water is supplied to the ozonated water utilization system via discharge line 7. Here, flow control valve V1 is set to open at an appropriate time, and water is replenished into tank 2.

[0030] Thereafter, when the supply of ozone water is stopped, the flow control valves V1, V3, and V4 are closed and the pump 3 is stopped. At this time, air and ozone gas bubbles remaining in the drain line 22, ejector 4, suction line 6, and pump 3 move into the tank 2.

[0031] According to the ozone water generator 1 described above, the pump 3 is disposed below the tank 2 that stores water, and the ejector 4 is disposed vertically between the tank 2 and the pump 3, allowing the pump 3 to be started with its suction side filled with water. The pump 3 requires priming, but since the tank 2 is located above the pump 3, the water in the tank 2 can be used as priming water. During this process, air and ozone gas bubbles within the pump 3 and its suction side (the drain line 22, the ejector 4, and the suction line 6) are transferred to the tank 2. In particular, since the ejector 4 is disposed vertically between the tank 2 and the pump 3, bubbles do not accumulate within the ejector 4 during operation of the ozone water generator 1. Therefore, the ozone water generator 1 reduces the amount of bubbles retained within the pump 3 and suppresses idling of the pump 3, stabilizing startup of the ozone water generator 1. It should be noted that the present invention is clearly applicable to a technique for generating a gas-dissolved liquid by injecting a gas other than ozone gas into a liquid flow in an ejector.

[0032] [Embodiment 2] The ozone water generation apparatus 1 of embodiment 2, which is one aspect of the present invention shown in Figure 2, is an aspect of embodiment 1, in which multiple ejectors 4 are arranged in parallel to generate a large amount of ozone water.

[0033] 3, the ejectors 4 are arranged at equal intervals on a concentric circle centered on the suction center of the pump 3, with the flow line of the fluid on the suction side of the pump 3 and the flow line of the working fluid of the ejectors 4 parallel to each other. The suction lines 6 on the discharge sides of the multiple ejectors 4 are combined into a single suction line 6 and connected to the suction side of the pump 3, so that the piping lengths from each ejector 4 to the pump 3 are set to be the same.

[0034] According to the ozone water generation apparatus 1 of the above-mentioned embodiment 2, the suction lines 6 on the discharge side of multiple ejectors 4 are consolidated into a single suction line 6 and led to the pump 3, thereby realizing, in addition to the effects of embodiment 1, an increased capacity of ozone water generated by the ozone water generation apparatus 1. [Explanation of symbols]

[0035] 1...Ozone water generator 2...tank, 21...water supply line, 22...drainage line, 23...exhaust line, 24, 25...gas supply lines, 26...pressure gauge 3. Pump 4...Ejector, 41...Injection line 5...Return line, 51...Flow meter 6...Suction line 7...Discharge line, 71...Concentration meter 8...Ozone decomposer V1,V2,V3,V4,V5,V6,V7…Flow control valve

Claims

1. A tank for storing water; a pump disposed below the tank; an ejector disposed vertically between the tank and the pump, which injects ozone gas sucked from the outside into the water introduced from the tank and discharges ozone water; a return line capable of returning the discharged ozone water to the tank; An ozone water generating apparatus comprising:

2. 2. The ozone water generating apparatus according to claim 1, wherein a plurality of the ejectors are arranged in parallel.

3. 3. The ozone water generating apparatus according to claim 2, wherein the ejectors are arranged at equal intervals on a concentric circle centered on the suction center of the pump.

4. 2. The ozone water generating apparatus according to claim 1, wherein the tank is provided with an exhaust line for discharging gas from the tank.

5. 5. The ozone water generating apparatus according to claim 4, wherein the exhaust line is provided with an ozone decomposer that decomposes ozone contained in the gas discharged from the tank.

6. A method for generating ozone water using an ozone water generating apparatus including a tank for storing water, a pump disposed below the tank, and an ejector disposed vertically between the tank and the pump, a step of injecting ozone gas sucked from the outside into the water introduced from the tank into the ejector, and discharging the ozone water from the ejector; A step of returning the discharged ozone water to the tank; 1. A method for generating ozone water, comprising:

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