Ozone supply device and ozone supply method

Abstract

This ozone supply device (100) is provided with: an ozone pipe (10) that connects an ozone generation device (6) and an adsorption tower (7); a decompression circuit (30) that sucks ozone gas desorbed from the adsorbent (7a) from the inside of the adsorption tower (7) and has a vacuum pump (12) that discharges the gas sucked from the suction port (121) from the discharge port (122), a primary pipe (15) that connects the suction port (121) and the ozone pipe (10), and a secondary pipe (19) that is connected to the discharge port (122); a dilution circuit (40) for mixing dilution air with the ozone gas flowing through the decompression circuit (30); a first flow meter (14) provided in the decompression circuit (30); a second flow meter (16) and a flow control valve (17) arranged in the dilution circuit (40); the pressure meter (13) is arranged in the adsorption tower (7); and a control device (18) that adjusts the opening degree of the flow rate control valve (17) such that the estimated ozone concentration value of the ozone gas discharged from the vacuum pump (12) to the secondary pipe (19) reaches a target value.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an ozone supply device and an ozone supply method that concentrate and hold ozone using an adsorption phenomenon of an adsorbent, and dilute and supply the held ozone. BACKGROUND

[0002] Ozone, which is a strong oxidizing agent, is widely used in various fields such as water environment purification and semiconductor cleaning, and there is an increasing demand for ozone generation technology that can produce high-concentration and high-efficiency ozone. Since ozone has a self-decomposition property, it is difficult to store in the gas phase at room temperature. Therefore, when ozone is supplied, an ozone supply device that intermittently generates ozone as needed is used.

[0003] As an ozone supply device, an ozone supply device that concentrates and holds ozone using an adsorption phenomenon of an adsorbent provided inside an adsorption tower, and dilutes and supplies the held ozone is generally used. In the ozone supply device that concentrates and supplies ozone using an adsorption phenomenon of an adsorbent, the ozone concentration inside the adsorption tower depends on the negative pressure state in the adsorption tower, and as the degree of vacuum in the tower increases, the ozone concentration increases. The ozone supply device that concentrates and supplies ozone using an adsorption phenomenon of an adsorbent shifts from an adsorption process in a pressurized state to a desorption process, and performs desorption by a decompression operation in the desorption process, and therefore as the desorption process proceeds, the degree of vacuum in the adsorption tower increases. Therefore, in the ozone supply device that concentrates and supplies ozone using an adsorption phenomenon of an adsorbent, the ozone concentration of ozone gas discharged from the adsorption tower fluctuates between a state in which the degree of vacuum is low before the decompression mechanism reaches a rated operation at the early stage of the desorption process and a state in which the degree of vacuum is high after the decompression mechanism reaches the rated operation at the late stage of the desorption process. Thus, the ozone supply device that concentrates and supplies ozone using an adsorption phenomenon of an adsorbent has a problem that the ozone concentration of the discharged ozone gas fluctuates.

[0004] Patent Literature 1 discloses an ozone supply device that connects a dilution gas introduction path to a transfer path of desorbed ozone gas from an ozone adsorbent that adsorbs and holds ozone gas, and detects the ozone concentration of ozone gas flowing in the desorbed ozone transfer path, and controls the dilution gas flow rate from the dilution gas introduction path based on the detected value of the ozone concentration, thereby being able to control both the ozone concentration and the flow rate of ozone gas discharged from the device. In the ozone supply device disclosed in Patent Literature 1, since the dilution gas flow rate from the dilution gas introduction path is controlled based on the detected value of the ozone concentration, fluctuation of the ozone concentration can be suppressed. SUMMARY

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 10-287404 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The ozone supply device disclosed in Patent Literature 1 measures the ozone concentration of the diluted ozone gas by an ozone concentration meter, however, it is known that the measurement performance of the ozone concentration meter changes over time. Therefore, even if the ozone supply device disclosed in Patent Literature 1 controls the dilution gas flow rate from the dilution gas introduction path based on the detected value of the ozone concentration, as time passes, even if the dilution gas flow rate from the dilution gas introduction path is controlled based on the detected value of the ozone gas concentration so that the detected value reaches a target value, the target value can be different from the actual ozone concentration, and it is not possible to stably supply ozone gas of the target ozone concentration.

[0009] The present disclosure was completed in view of the above, and aims to obtain an ozone supply device capable of stably supplying ozone gas of a target ozone concentration.

[0010] MEANS OF SOLVING THE PROBLEMS

[0011] In order to solve the above problems and achieve the aim, the ozone supply device according to the present disclosure includes: an ozone generation device that generates an ozonated gas containing ozone gas; an adsorption tower that has an adsorbent that adsorbs the ozone gas contained in the ozonated gas; an ozone pipe that connects the ozone generation device and the adsorption tower; and a decompression circuit that has a decompression mechanism that discharges gas taken in from a suction port from a discharge port, a primary pipe that connects the suction port and the ozone pipe, and a secondary pipe connected to the discharge port, and that draws ozone gas desorbed from the adsorbent from the inside of the adsorption tower through the ozone pipe. The ozone supply device includes: a dilution circuit that mixes dilution air with ozone gas flowing in the decompression circuit; a first flowmeter provided in the decompression circuit; a second flowmeter and a flow rate adjustment valve provided in the dilution circuit; a pressure gauge provided in the adsorption tower; and a control device that, based on the respective measurement values of the first flowmeter, the second flowmeter, and the pressure gauge, estimates the ozone concentration of the ozone gas discharged by the decompression mechanism to the secondary pipe, and adjusts the opening degree of the flow rate adjustment valve so that the estimated value of the ozone concentration of the ozone gas discharged by the decompression mechanism to the secondary pipe reaches a target value set in advance.

[0012] EFFECTS OF THE INVENTION

[0013] According to the present disclosure, there is an effect of being able to obtain an ozone supply device capable of stably supplying ozone gas of a target ozone concentration. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Fig. 1 is a diagram showing the structure of an ozone supply device according to Embodiment 1.

[0015] Figure 2 Fig. 2 is a diagram showing the change in the pressure inside the adsorption tower of the ozone supply device according to Embodiment 1 over time.

[0016] Figure 3 Fig. 3 is a diagram showing the structure of the control device of the ozone supply device according to Embodiment 1.

[0017] Figure 4 Fig. 4 is a diagram showing an example of the relationship between the pressure inside the adsorption tower of the ozone supply device according to Embodiment 1 and the ozone concentration of the desorbed ozone gas.

[0018] Figure 5 Fig. 5 is a flowchart showing the flow of the operation of the ozone supply device according to Embodiment 1 in the desorption process.

[0019] Figure 6 Fig. 6 is a diagram showing the structure of an ozone supply device according to Embodiment 2.

[0020] Figure 7 Fig. 7 is a flowchart showing the flow of the operation of the ozone supply device according to Embodiment 2 in the ozone desorption.

[0021] Figure 8 Fig. 8 is a diagram showing the structure of the control device of the ozone supply device according to Embodiment 3.

[0022] Figure 9 Fig. 9 is a flowchart showing the flow of the operation of the ozone supply device according to Embodiment 3 in the ozone desorption.

[0023] Figure 10 Fig. 10 is a diagram showing the structure of an ozone supply device according to Embodiment 4.

[0024] Figure 11 Fig. 11 is a diagram showing the hardware structure of the control device of the ozone supply device according to Embodiments 1 to 4. DETAILED DESCRIPTION

[0025] Hereinafter, the ozone supply device and the ozone supply method according to the embodiments will be described in detail based on the drawings.

[0026] Embodiment 1.

[0027] Figure 1is a view showing the structure of an ozone supply device according to Embodiment 1. The ozone supply device 100 according to Embodiment 1 includes a compressor 1 that compresses air; a dryer 2 that dehumidifies the compressed air; an air tank 3 that stores the dehumidified compressed air; an oxygen generator 4 that separates oxygen gas contained in the dehumidified compressed air; a raw material gas tank 5 that stores a raw material gas; and an ozone generator 6 that generates an ozonated gas containing ozone gas from the raw material gas. In addition, the ozone supply device 100 is provided with an adsorption tower 7 provided with an adsorbent 7a for adsorbing ozone gas; a circulation pump 8 that sends the ozonated gas that has not been adsorbed by the adsorbent 7a in the adsorption tower 7 back to the raw material gas tank 5; a cooler 9 that cools the ozonated gas sent from the adsorption tower 7 back to the raw material gas tank 5; and a desorption purge circuit 11 that supplies the dehumidified compressed air in the air tank 3 to the adsorption tower 7 and causes the ozone gas adsorbed by the adsorbent 7a to be desorbed.

[0028] The ozone generator 6 can be a silent discharge type ozone generator driven by an alternating current high voltage, but is not limited thereto.

[0029] In addition, the ozone supply device 100 includes a vacuum pump 12 as a pressure reducing mechanism that discharges the gas taken in from the suction port 121 from the discharge port 122; a primary pipe 15 that connects the suction port 121 and the ozone pipe 10; and a secondary pipe 19 connected to the discharge port 122, and further includes a pressure reducing circuit 30 that draws the ozone gas desorbed from the adsorbent 7a from the inside of the adsorption tower 7 through the ozone pipe 10. Here, the pressure reducing mechanism is exemplified as the structure of the vacuum pump 12, but the pressure reducing mechanism can also be an ejector that draws gas using pressurized driving gas. The ozone gas discharged from the discharge port 122 of the vacuum pump 12 to the secondary pipe 19 is dissolved in the water to be treated 60, thereby generating ozone water, and the generated ozone water can be used, for example, for water environmental purification and semiconductor cleaning.

[0030] In addition, the ozone supply device 100 is provided with a dilution circuit 40 that mixes dilution air with the ozone gas flowing in the pressure reducing circuit 30. The dilution air is air for diluting the ozone concentration of the ozone gas discharged from the discharge port 122 to the secondary pipe 19 to a target ozone concentration. In the ozone supply device 100 according to Embodiment 1, the dilution circuit 40 mixes the dilution air with the ozone gas flowing in the primary pipe 15.

[0031] The ozone supply device 100 is provided with a first flowmeter 14 disposed in the pressure reducing circuit 30, a second flowmeter 16 and a flow regulating valve 17 disposed in the dilution circuit 40, and a pressure gauge 13 disposed in the adsorption tower 7. The pressure gauge 13 measures the pressure inside the adsorption tower 7. The first flowmeter 14 measures the flow rate of the ozone gas before being diluted by the dilution air flowing in the primary pipe 15. The second flowmeter 16 measures the flow rate of the dilution air supplied from the dilution circuit 40 to the primary pipe 15. The flow regulating valve 17 regulates the flow rate of the dilution air supplied from the dilution circuit 40 to the primary pipe 15.

[0032] The ozone supply device 100 includes a control device 18. The control device 18 controls the opening degree of the flow regulating valve 17 based on the measured values of the pressure gauge 13, the first flowmeter 14, and the second flowmeter 16.

[0033] Figure 2 is a graph showing the change in the pressure inside the adsorption tower of the ozone supply device according to Embodiment 1 over time. The ozone supply device 100 generates ozone gas by alternately performing an adsorption process of causing the adsorbent 7a disposed in the adsorption tower 7 to adsorb ozone, and a desorption process of causing the ozone adsorbed by the adsorbent 7a to desorb to generate desorbed ozone gas.

[0034] In the adsorption process, the pressure inside the adsorption tower 7 rises to a first pressure P1 set in advance by supplying the ozonized gas containing ozone gas from the ozone generator 6 to the adsorption tower 7. In the desorption process, the pressure inside the adsorption tower 7 connected to the ozone pipe 10 falls to a second pressure P2 set in advance by the vacuum pump 12 sucking the ozone gas in the ozone pipe 10.

[0035] In the adsorption process, the ozonized gas generated based on the raw material gas stored in the raw material gas tank 5 flows into the adsorption tower 7 by the ozone generator 6, and the ozone gas is adsorbed on the adsorbent 7a disposed in the adsorption tower 7. In addition, the ozonized gas containing the ozone gas that is not adsorbed by the adsorbent 7a in the adsorption tower 7 is sent back to the raw material gas tank 5 by the circulation pump 8. Therefore, the raw material gas in the raw material gas tank 5 is a mixed gas of the oxygen gas generated by the oxygen generator 4 and the ozonized gas.

[0036] In the desorption process, air is supplied to the adsorption tower 7 by the desorption purge circuit 11, and the ozone gas adsorbed on the adsorbent 7a is replaced and desorbed by the compressed air to generate ozone gas inside the adsorption tower 7. In addition, a negative pressure is generated by the vacuum pump 12, and the ozone gas in the adsorption tower 7 connected to the ozone pipe 10 is sucked into the vacuum pump 12 through the primary pipe 15 and discharged to the outside of the device through the secondary pipe 19.

[0037] Figure 3is a diagram showing the structure of a control device of the ozone supply device according to Embodiment 1. The control device 18 includes a table storage section 181 that stores an ozone concentration table 181a indicating a correspondence relationship between the pressure inside the adsorption tower 7 and the ozone concentration of the ozone gas inside the adsorption tower 7 at the time of pressure reduction desorption, an ozone concentration estimation section 182 that estimates the ozone concentration of the ozone gas inside the adsorption tower 7 based on the pressure inside the adsorption tower 7 measured by the pressure gauge 13 by referring to the ozone concentration table 181a, and a flow rate adjustment section 183 that adjusts the opening degree of the flow rate adjustment valve 17 based on the estimation result of the ozone concentration of the ozone gas inside the adsorption tower 7.

[0038] Figure 4 is a diagram showing an example of the relationship between the pressure inside the adsorption tower of the ozone supply device according to Embodiment 1 and the ozone concentration of the ozone gas inside the adsorption tower. If the adsorption conditions in the adsorption process are values set in advance, as shown in Figure 4 , the pressure inside the adsorption tower 7 and the ozone concentration of the ozone gas inside the adsorption tower correspond one-to-one. In addition, the adsorption conditions in the adsorption process can be cited as the adsorption ozone concentration, the pressure, and the temperature, and the like. The ozone concentration table 181a is generated based on the relationship between the pressure inside the adsorption tower and the ozone concentration of the ozone gas inside the adsorption tower shown in Figure 4 . Therefore, the ozone concentration estimation section 182 can uniquely determine the ozone concentration of the ozone gas corresponding to the pressure inside the adsorption tower 7 by referring to the ozone concentration table 181a.

[0039] Figure 5 is a flowchart showing the flow of the operation of the ozone supply device according to Embodiment 1 in the desorption process. In addition, in the desorption process, the ozone supply device 100 is in a state in which the compressed air is supplied to the adsorption tower 7 through the desorption purge circuit 11, and the ozone gas is sucked from the ozone pipe 10 by the vacuum pump 12.

[0040] In step S101, the ozone concentration estimation section 182 acquires information on the pressure inside the adsorption tower 7 measured by the pressure gauge 13.

[0041] In step S102, the ozone concentration estimation section 182 acquires information on the flow rate of the ozone gas before being diluted by the diluted air flowing through the primary pipe 15 measured by the first flowmeter 14.

[0042] In step S103, the ozone concentration estimation section 182 acquires information on the flow rate of the diluted air supplied to the primary pipe 15 by the diluted circuit 40 measured by the second flowmeter 16.

[0043] In step S104, the ozone concentration estimation section 182 estimates the ozone concentration of the ozone gas flowing through the primary pipe 15 before being diluted by the dilution air, based on the pressure inside the adsorption tower 7, by referring to the ozone concentration table 181a.

[0044] In step S105, the ozone concentration estimation section 182 calculates an estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19, based on the estimated value of the ozone concentration of the ozone gas flowing through the primary pipe 15 before being diluted by the dilution air, the flow rate of the ozone gas flowing through the primary pipe 15 before being diluted by the dilution air, and the flow rate of the dilution air supplied to the primary pipe 15 by the dilution circuit 40.

[0045] In step S106, the flow rate adjustment section 183 compares the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 with the target ozone concentration D. If the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is a value higher than the target ozone concentration D set in advance, E > D in step S106, in step S107, the flow rate adjustment section 183 increases the opening degree of the flow rate adjustment valve 17. If the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is a value lower than the target ozone concentration D, E < D in step S106, in step S108, the flow rate adjustment section 183 decreases the opening degree of the flow rate adjustment valve 17. If the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is the same as the target ozone concentration D, E = D in step S106, the flow rate adjustment section 183 does not change the opening degree of the flow rate adjustment valve 17 and ends the process. Note that, here, the case where the opening degree of the flow rate adjustment valve 17 is controlled based on the magnitude relationship between the target ozone concentration D set in advance and the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is exemplified, but it can also be that if the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is a value lower than the ozone concentration region that is lower than the target ozone concentration D by a first value set in advance, the opening degree of the flow rate adjustment valve 17 is decreased, and if the estimated value E of the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 is a value higher than the ozone concentration region that is higher than the target ozone concentration D by a second value set in advance, the opening degree of the flow rate adjustment valve 17 is increased. In this case, the first value and the second value can be the same value or different values. Thus, it is possible to decrease the frequency of controlling the opening degree of the flow rate adjustment valve 17.

[0046] As an ozone concentration meter that measures the ozone concentration in the ozone gas, an ultraviolet absorption type ozone concentration meter that utilizes the characteristic that ozone strongly absorbs 254 nm wavelength and measures the ozone concentration based on the amount of light absorption is generally used, however, the ultraviolet absorption type ozone concentration meter is more expensive than a general pressure gauge. In the ozone supply device 100 according to Embodiment 1, since the ozone concentration of the ozone gas inside the adsorption tower 7 is estimated based on the pressure measured by the pressure gauge 13, the manufacturing cost can be reduced compared to an ozone supply device that measures the ozone concentration of the ozone gas inside the adsorption tower 7 with an ozone concentration meter.

[0047] Further, in a case where dirt having a size that cannot be confirmed with the naked eye is present in the light emitting portion or the light receiving portion of the ultraviolet absorption type ozone concentration meter, the ultraviolet light is blocked by the dirt, and thus the measured ozone concentration is higher than the original value. Therefore, in an ozone supply device that measures the ozone concentration of the ozone gas inside the adsorption tower with an ultraviolet absorption type ozone concentration meter, in order to perform maintenance on the ozone concentration meter, the supply of ozone needs to be stopped periodically. In contrast, in the ozone supply device 100 according to Embodiment 1, since the ozone concentration of the ozone gas inside the adsorption tower 7 is estimated based on the pressure measured by the pressure gauge 13, there is no need to perform maintenance on the ozone concentration meter, and reduction of the maintenance cost and stable supply of the ozone gas at the target ozone concentration can be achieved.

[0048] In addition, in the ozone supply device 100 according to Embodiment 1, since the dilution circuit 40 supplies the dilution air to the primary pipe 15, the ozone concentration of the ozone gas flowing into the vacuum pump 12 can be reduced. Therefore, the deterioration of the vacuum pump 12 due to the corrosion of the ozone gas can be suppressed.

[0049] Embodiment 2.

[0050] Figure 6 is a view that shows the structure of the ozone supply device according to Embodiment 2. In the ozone supply device 100 according to Embodiment 2, an ozone concentration meter 20 is provided in the secondary pipe 19, unlike the ozone supply device 100 according to Embodiment 1. Other than this, the ozone supply device 100 according to Embodiment 2 is the same as the ozone supply device 100 according to Embodiment 1. The ozone concentration meter 20 measures the ozone concentration of the ozone gas inside the secondary pipe 19 after being diluted by the dilution air.

[0051] The ozone concentration meter 20 outputs the measurement result of the ozone concentration of the ozone gas inside the secondary pipe 19 after being diluted by the dilution air to the control device 18.

[0052] Figure 7is a flow chart showing a flow of the operation of the ozone supply device according to Embodiment 2 at the time of ozone desorption. The processes from Step S201 to Step S208 are the same as the processes of Steps S101 to S108 of the operation of the ozone supply device 100 according to Embodiment 1 at the time of ozone desorption. In Step S209, the flow rate adjusting section 183 acquires the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air from the ozone concentration meter 20. In Step S210, the flow rate adjusting section 183 compares the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air with the target ozone concentration D. If the measured value M of the ozone concentration of the ozone gas flowing in the secondary pipe 19 is a value higher than the target ozone concentration D, M > D in Step S210, in Step S211, the control device 18 increases the opening degree of the flow rate adjusting valve 17. If the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air is a value lower than the target ozone concentration D, M < D in Step S210, in Step S212, the control device 18 decreases the opening degree of the flow rate adjusting valve 17. If the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air is the same as the target ozone concentration D, E = D in Step S210, the control device 18 does not change the opening degree of the flow rate adjusting valve 17, and ends the process.

[0053] In addition, although the case where the opening degree of the flow rate adjusting valve 17 is controlled based on the size relationship between the target ozone concentration D set in advance and the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air is described here as an example, the opening degree of the flow rate adjusting valve 17 can be decreased if the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air is a value lower than the ozone concentration region that is lower than the target ozone concentration D by a third value set in advance, and the opening degree of the flow rate adjusting valve 17 can be increased if the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air is a value higher than the ozone concentration region that is higher than the target ozone concentration D by a fourth value set in advance. In this case, the third value and the fourth value can be the same value or different values. Thus, the frequency of controlling the opening degree of the flow rate adjusting valve 17 can be decreased.

[0054] In the control device 18 of the ozone supply device 100 according to Embodiment 2, the flow rate adjustment valve 17 is feedback controlled based on the measured value of the concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air, and thus the supply amount of the dilution air is adjusted, so that the concentration of the ozone gas discharged from the secondary pipe 19 to the outside can be made closer to the target ozone concentration. Since the ozone concentration meter 20 provided in the secondary pipe 19 can be detached without disassembling the adsorption tower 7, maintenance is easy, and thus the variation of the measured value of the ozone concentration does not exceed the allowable value. Therefore, the ozone supply device 100 according to Embodiment 2 can suppress the variation of the measured value over time by periodically performing maintenance of the ozone concentration meter 20.

[0055] Embodiment 3.

[0056] Figure 8 is a view showing the structure of the control device of the ozone supply device according to Embodiment 3. The ozone supply device 100 according to Embodiment 3 is different from the ozone supply device 100 according to Embodiment 2 in that the control device 18 is provided with an abnormality diagnosing section 184 and an abnormality notifying section 185. Other than this, the ozone supply device 100 according to Embodiment 3 is the same as the ozone supply device 100 according to Embodiment 2.

[0057] The abnormality diagnosing section 184 determines that an abnormality has occurred when the difference between the measured value M of the ozone concentration of the ozone gas in the secondary pipe 19 diluted by the dilution air and the estimated value E of the concentration of the ozone gas discharged from the secondary pipe 19 by the vacuum pump 12 is greater than a threshold value set in advance, and causes the abnormality notifying section 185 to notify that an abnormality has occurred. The abnormality notifying section 185 can be a display device such as a liquid crystal display that can display a message, or can be an alarm lamp that notifies that an abnormality has occurred by being lit or flashing.

[0058] Figure 9 is a flowchart showing the flow of the operation of the ozone supply device according to Embodiment 3 at the time of ozone desorption. The processes from Step S301 to Step S308 are the same as the processes of Steps S101 to S108 of the operation of the ozone supply device 100 according to Embodiment 1 at the time of ozone desorption.

[0059] In step S309, the control device 18 acquires the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air from the ozone concentration meter 20. In step S310, the control device 18 determines whether the difference between the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air and the estimated value E of the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 is greater than a threshold value set in advance. If the difference between the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air and the estimated value E of the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 is below the threshold value set in advance, the determination in step S310 is "No", and the process ends. If the difference between the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air and the estimated value E of the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 is greater than the threshold value set in advance, the determination in step S310 is "Yes", and in step S311, the control device 18 causes the abnormality notification section 185 to notify of an abnormality.

[0060] If the adsorbent 7a provided inside the adsorption tower 7 deteriorates, the amount of the ozone gas stored in the adsorption tower 7 decreases, the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 decreases, and thus the difference between the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air and the estimated value E of the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 increases. The ozone supply device 100 according to Embodiment 3 is capable of notifying of an abnormality when the difference between the measurement value M of the ozone concentration of the ozone gas in the secondary piping 19 diluted by the diluted air and the estimated value E of the concentration of the ozone gas discharged from the vacuum pump 12 to the secondary piping 19 is greater than the threshold value set in advance. Thus, the user of the ozone supply device 100 according to Embodiment 3 can determine whether the adsorbent 7a provided inside the adsorption tower 7 deteriorates without disassembling the adsorption tower 7.

[0061] Embodiment 4.

[0062] Figure 10 is a view showing the structure of the ozone supply device according to Embodiment 4. The ozone supply device 100 according to Embodiment 4 differs from the ozone supply device 100 according to Embodiment 2 in that the dilution circuit 40 mixes the diluted air with the ozone gas flowing in the secondary piping 19. Other than that, the ozone supply device 100 according to Embodiment 4 is the same as the ozone supply device 100 according to Embodiment 2.

[0063] In the ozone supply device 100 according to Embodiment 4, since the dilution circuit 40 supplies the dilution air to the secondary pipe 19 to adjust the concentration of the ozone gas, the dilution air does not flow into the vacuum pump 12. Therefore, a small vacuum pump 12 with a small exhaust capacity can be applied, and the size of the device can be reduced.

[0064] Figure 11 is a view showing a hardware structure of the control device of the ozone supply device according to Embodiments 1 to 4. The control device 18 is realized by a computer system including a processor 91 that performs various processes, a memory 92 as a main memory, and a storage device 93 that stores information.

[0065] The processor 91 can be an arithmetic device, a microprocessor, a microcomputer, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor), or the like. In addition, the memory 92 can use a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable Read Only Memory), an EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), or the like, which is a nonvolatile or volatile semiconductor memory. The storage device 93 stores a program for performing processes of estimating the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19, adjusting the flow rate of the dilution air mixed with the ozone gas flowing in the decompression circuit 30 by the dilution circuit 40, and making the ozone concentration of the ozone gas discharged from the vacuum pump 12 to the secondary pipe 19 reach the target ozone concentration.

[0066] The above computer system realizes the functions of the control device 18 by the processor 91 reading the program corresponding to the processes of each constituent element stored in the storage device 93 into the memory 92 and executing it. In addition, the memory 92 is also used as a temporary memory in each process executed by the processor 91. The program executed by the processor 91 can be provided in a state of being stored in a storage medium, or can be provided via a network.

[0067] In addition, in Embodiments 1 to 4, the ozone supply device 100 provided with the control device 18 is described, but the control device 18 can be provided as a device independent of the ozone supply device 100.

[0068] In addition, the structure shown in the above embodiments represents one example of the contents, and can be combined with other publicly known technologies, or a part of the structure can be omitted or changed without departing from the scope of the gist.

[0069] Explanation of Reference Numerals

[0070] 1 compressor, 2 dryer, 3 air tank, 4 oxygen generating device, 5 raw material gas tank, 6 ozone generating device, 7 adsorption tower, 7a adsorbent, 8 circulating pump, 9 cooler, 10 ozone piping, 11 desorption purge circuit, 12 vacuum pump, 13 pressure gauge, 14 first flow meter, 15 first stage piping, 16 second flow meter, 17 flow regulating valve, 18 control device, 19 second stage piping, 20 ozone concentration meter, 30 pressure reduction circuit, 40 dilution circuit, 60 water to be treated, 91 processor, 92 memory, 93 storage device, 100 ozone supply device, 121 suction port, 122 discharge port, 181 table storage section, 181a ozone concentration table, 182 ozone concentration estimation section, 183 flow regulating section, 184 abnormality diagnosis section, 185 abnormality notification section.

Claims

1. An ozone supply device, characterized in that, include: An ozone generator that produces ozonated gas containing ozone gas; An adsorption tower having an adsorbent for adsorbing the ozone gas contained in the ozonated gas; Ozone piping, which connects the ozone generator and the adsorption tower; A pressure-reducing circuit having a pressure-reducing mechanism for discharging gas drawn in from the inlet from the outlet, a primary piping connecting the inlet and the ozone piping, and a secondary piping connecting the outlet, wherein the ozone gas desorbed from the adsorbent is drawn from inside the adsorption tower through the ozone piping; A dilution circuit that mixes diluted air with ozone gas flowing through the pressure reduction circuit; A first flow meter is installed in the pressure reducing circuit; A second flow meter and a flow regulating valve are provided in the dilution circuit; A pressure gauge is installed in the adsorption tower; as well as A control device, based on the measurements of the first flow meter, the second flow meter, and the pressure gauge, estimates the ozone concentration of the ozone gas discharged into the secondary piping by the pressure reducing mechanism, and adjusts the opening of the flow regulating valve so that the estimated ozone concentration of the ozone gas discharged into the secondary piping by the pressure reducing mechanism reaches a preset target value.

2. The ozone supply device as described in claim 1, characterized in that, The secondary piping includes an ozone meter that measures the ozone concentration of the ozone gas after it has been diluted with the dilution air. The control device performs feedback control on the opening degree of the flow regulating valve based on the measurement value of the ozone concentration meter.

3. The ozone supply device as described in claim 2, characterized in that, The control device includes: An anomaly diagnosis unit determines an anomaly has occurred if the difference between the measured ozone concentration of the ozone gas diluted with the dilution air, obtained from the ozone concentration meter, and the estimated ozone concentration of the ozone gas diluted with the dilution air, exceeds a preset threshold; and The exception notification department notifies that the aforementioned exception has occurred.

4. The ozone supply device as described in claim 1, characterized in that, The secondary piping includes an ozone meter that measures the ozone concentration of the ozone gas after it has been diluted with the dilution air. The control device includes: An anomaly diagnosis unit determines an anomaly has occurred if the difference between the measured ozone concentration of the ozone gas diluted with the dilution air, obtained from the ozone concentration meter, and the estimated ozone concentration of the ozone gas diluted with the dilution air, exceeds a preset threshold; and The exception notification department notifies that the aforementioned exception has occurred.

5. The ozone supply device according to any one of claims 1 to 4, characterized in that, The dilution circuit mixes the dilution air with the ozone gas flowing through the primary piping.

6. The ozone supply device according to any one of claims 1 to 4, characterized in that, The dilution circuit mixes the dilution air with the ozone gas flowing through the secondary piping.

7. An ozone supply method, characterized in that, include: The steps of measuring the pressure inside an adsorption tower containing an adsorbent that adsorbs ozone gas, the flow rate of ozone gas drawn from the adsorption tower by a pressure reducing mechanism, and the flow rate of dilution air mixed with the ozone gas drawn from the adsorption tower by the pressure reducing mechanism. The step of estimating the ozone concentration of the ozone gas after dilution by the dilution air based on the measured values ​​of the pressure inside the adsorption tower, the flow rate of ozone gas drawn from the adsorption tower by the pressure reducing mechanism, and the flow rate of the dilution air; and The step of adjusting the flow rate of the dilution air so that the estimated ozone concentration of the ozone gas after being diluted by the dilution air reaches a predetermined target value.

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