Ozone supply system and ozone supply method

Abstract

This ozone supply system is provided with: adsorption towers (A, B) that contain an adsorption material for adsorbing ozone generated from oxygen supplied from an oxygen source (2) by an ozone generator (3), and that alternately repeat an adsorption step for adsorbing ozone to the adsorption material and a desorption step for desorbing ozone from the adsorption material; a circulation path (120) that, in the adsorption step, leads out oxygen gas that has not been adsorbed by the adsorption material from the adsorption towers (A, B) and circularly supplies the oxygen gas to the ozone generator (3); a first supply unit (4) for a first carrier gas; a carrier gas introduction path (103) for introducing a first carrier gas from the first supply unit (4) into the adsorption towers (A, B) in the desorption step; a carrier gas discharge path (104) for discharging ozone accompanying the first carrier gas to the outside of the adsorption towers (A, B) in the desorption step; and a pressure reduction unit (5) for reducing the pressure in the desorption step until the pressure in the adsorption towers (A, B) is lower than atmospheric pressure.

Description

Technical Field

[0001] This application relates to ozone supply systems and methods. Background Technology

[0002] Conventional ozone supply systems include: a high-purity oxygen supply source that supplies high-purity oxygen as ozone feedstock; an ozone generator that produces ozone using the high-purity oxygen supplied from the high-purity oxygen supply source as feedstock; an adsorption cartridge filled with an adsorbent that preferentially adsorbs ozone, adsorbing ozone generated by the ozone generator in a relatively low-temperature adsorption process and alternately performing desorption operations in a relatively high-temperature desorption process; and an oxygen circulation path that recirculates and mixes the oxygen that is not adsorbed by the adsorbent in the adsorption process and exits from the adsorption cartridge into the high-purity oxygen supply source. The ozone chamber contains: a purge gas inlet path, which introduces purge gas, used to accompany ozone desorbed from the adsorbent in the desorption process, from the adsorption chamber into the adsorption chamber; an ozone outlet path, which exports ozone-accompanying purge gas from the adsorption chamber in the desorption process; an ozone supply path, which supplies the ozone-accompanying purge gas exported to the ozone outlet path as product ozone to the ozone consumption target; and a pump, which draws the gas in the adsorption chamber, pressurizes it, introduces it into the product ozone, and mixes it (e.g., see Patent Document 1).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2001-172004 Summary of the Invention

[0004] The technical problem that the invention aims to solve In previous ozone supply systems and methods, low-concentration oxygen was used for purging to reduce oxygen consumption. As a result, nitrogen introduced during desorption remained in the adsorption tower, leading to a higher nitrogen concentration in the tower during the transfer from ozone gas desorption to adsorption. This resulted in reduced ozone generation efficiency and the formation of nitrogen oxides, which contribute to corrosion along the ozone path.

[0005] This application discloses a technology for solving the above-mentioned technical problems, the purpose of which is to provide an ozone supply system and ozone supply method that can suppress the rise of nitrogen concentration in the adsorption tower.

[0006] Technical solutions to solve technical problems The ozone supply system disclosed in this application includes: An ozone generator that produces ozone from oxygen supplied from an oxygen source; An adsorption tower that holds an adsorption material for adsorbing ozone generated by the ozone generator, and alternately and repeatedly performs an adsorption process in which ozone is adsorbed onto the adsorption material and a desorption process in which ozone is desorbed from the adsorption material. A circulation path, in the adsorption process, removes oxygen that has not been adsorbed by the adsorption material from the adsorption tower and supplies it to the ozone generator in a circulating manner. First supply unit for first carrier gas; A carrier gas introduction path, wherein the carrier gas is introduced from the first supply section into the adsorption tower during the desorption process; A carrier gas exit path, which, during the desorption process, exits the ozone accompanying the first carrier gas outside the adsorption tower; and The depressurization section reduces the pressure in the desorption process until the pressure inside the adsorption tower is below atmospheric pressure.

[0007] Furthermore, the ozone supply method disclosed in this application includes: The adsorption process involves adsorbing the generated ozone by the adsorbent material housed in the adsorption tower and removing the oxygen that was not adsorbed by the adsorbent material from the adsorption tower. The oxygen that was not adsorbed by the adsorbent material is then introduced back into the ozone generator as a raw material gas to generate ozone again, and the regenerated ozone is supplied to the adsorption tower. A first desorption step, which, after the adsorption step is completed, introduces a first carrier gas into the adsorption tower to desorb the ozone adsorbed on the adsorbent material along with the first carrier gas and export it outside the adsorption tower; and The vacuum desorption process involves reducing the pressure after the first carrier gas is stopped being introduced until the pressure inside the adsorption tower is lower than atmospheric pressure.

[0008] Furthermore, the ozone supply method disclosed in this application includes: The adsorption process involves adsorbing the generated ozone by the adsorbent material housed in the adsorption tower and removing the oxygen that was not adsorbed by the adsorbent material from the adsorption tower. The oxygen that was not adsorbed by the adsorbent material is then introduced back into the ozone generator as a raw material gas to generate ozone again, and the regenerated ozone is supplied to the adsorption tower. A first desorption step, which, after the adsorption step is completed, introduces a first carrier gas into the adsorption tower to desorb the ozone adsorbed on the adsorbent material along with the first carrier gas and export it outside the adsorption tower; and In the second desorption step, after stopping the introduction of the first carrier gas, a second carrier gas with a lower nitrogen concentration than the first carrier gas is introduced to desorb the ozone adsorbed on the adsorption material and export it outside the adsorption tower, and the first carrier gas remaining in the adsorption tower is replaced with the second carrier gas.

[0009] Invention Effects The ozone supply system and ozone supply method disclosed in this application can suppress the rise in nitrogen concentration in the adsorption tower. Attached Figure Description

[0010] Figure 1 This is a block diagram illustrating the structure of the ozone supply system involved in Embodiment 1.

[0011] Figure 2 It means that it was used Figure 1 The flowchart shows the process of the ozone supply method for the ozone supply system.

[0012] Figure 3 This is a block diagram illustrating the structure of the ozone supply system involved in Embodiment 2.

[0013] Figure 4 It means that it was used Figure 3 The flowchart shows the process of the ozone supply method for the ozone supply system.

[0014] Figure 5 It means that it was used Figure 3 A flowchart of the steps of other ozone supply methods for the ozone supply system shown. Detailed Implementation

[0015] Implementation method 1. Figure 1 This is a block diagram illustrating the structure of the ozone supply system involved in Embodiment 1. Figure 2 It means that it was used Figure 1 The flowchart illustrates the steps of the ozone supply method in the ozone supply system shown. Figure 1 In the ozone supply system 1, there are adsorption tower A and adsorption tower B, ozone generator 3 connected to both adsorption tower A and adsorption tower B, ozone introduction path 101, circulation path 120, first carrier gas introduction path 103, carrier gas outlet path 104, first supply unit 4, and pressure reduction unit 5.

[0016] Adsorption towers A and B store adsorbent materials for adsorbing ozone. The ozone supply system 1 alternately switches between an adsorption process in adsorption towers A and B, where ozone is adsorbed onto the adsorbent materials, and a desorption process, where ozone is desorbed from the adsorbent materials. The ozone generator 3 introduces oxygen from the oxygen source 2 via a buffer tank 122 (described later), generates ozone, and supplies oxygen to adsorption towers A or B in the adsorption process via ozone introduction path 101. The circulation path 120 includes: a circulation blower 121 for circulating oxygen, i.e., removing unadsorbed oxygen from adsorption towers A or B in the adsorption process and re-introducing it into the ozone generator 3 for reuse as a feed gas; and a buffer tank 122 for temporarily storing the circulating oxygen.

[0017] The first supply unit 4 supplies a first carrier gas for desorbing ozone adsorbed on the adsorbent material to the adsorption tower A or adsorption tower B in the desorption process via the first carrier gas inlet path 103. Dry air is used as the first carrier gas, for example. The carrier gas outlet path 104 discharges the ozone accompanying the first carrier gas from the adsorption tower A or adsorption tower B in the desorption process to the pressure reducing unit 5.

[0018] The pressure reduction unit 5 reduces pressure via the carrier gas outlet path 104 until the pressure inside adsorption tower A or adsorption tower B, which is in the desorption process, becomes lower than atmospheric pressure. The pressure reduction unit 5 is, for example, composed of a vacuum pump. Furthermore, switching valves 11, 12, 13, 14, 15, 16, 17, and 18 are respectively installed in these paths 101, 12, 13, 14, 15, 16, 17, and 18, which open and close in a predetermined sequence when switching between adsorption tower A and adsorption tower B.

[0019] Next, the ozone supply method of the ozone supply system of Embodiment 1, as described above, will be explained. Here, the explanation will focus on adsorption tower A. Of course, if the adsorption process is performed in adsorption tower A, the desorption process is performed in adsorption tower B. Conversely, if the desorption process is performed in adsorption tower A, the adsorption process is performed in adsorption tower B. Therefore, these situations also apply to the following embodiments, and their descriptions will be appropriately omitted.

[0020] First, ozone generator 3 introduces oxygen from oxygen source 2 to generate ozone, which is then introduced into adsorption tower A, which is in the adsorption process, via ozone introduction path 101. Next, the introduced ozone is adsorbed by the adsorbent material inside adsorption tower A. Simultaneously, oxygen not adsorbed by the adsorbent material in adsorption tower A is discharged from adsorption tower A via circulation path 120, and then supplied back to ozone generator 3 as raw material gas via circulation blower 121 and buffer tank 122. Figure 2Step ST01). At this time, the pressure inside adsorption tower A becomes a pressure state greater than atmospheric pressure. Then, when the adsorption process of adsorption tower A ends, the introduction of ozone from ozone generator 3 into adsorption tower A is stopped.

[0021] Next, in adsorption tower A undergoing the desorption process, the first supply unit 4 introduces dry air as the first carrier gas via the first carrier gas introduction path 103. The introduced first carrier gas then purges the ozone adsorbed on the adsorbent material of adsorption tower A outward along with the first carrier gas via the carrier gas outlet path 104, thus performing the first desorption process. Figure 2 (Step ST02). At this time, since dry air is introduced into the adsorption tower A, the pressure inside the adsorption tower A is reduced to about atmospheric pressure. In addition, in the first desorption process, an example is shown in which the ozone accompanying the first carrier gas is discharged to the outside of the device via the carrier gas outlet path 104 through the pressure reducing unit 5, but it is not limited to this. In the first desorption process, it is also possible to discharge the ozone directly to the outside of the device without passing through the pressure reducing unit 5.

[0022] Next, a vacuum desorption process is performed. Figure 2 In step ST03), after the introduction of the first carrier gas is stopped, the vacuum desorption process depressurizes the adsorption tower A through the depressurization unit 5 via the carrier gas outlet path 104 until the pressure inside the adsorption tower A is lower than atmospheric pressure. At this time, the portion of the first carrier gas remaining in the adsorption tower A and the carrier gas outlet path 104 is discharged. Therefore, since the accumulation of nitrogen in the adsorption tower A can be reduced, the amount of NOx gas generated, which increases with the increase of nitrogen in the circulation path 120 in the next adsorption process (step ST01), can be reduced. As a result, the decrease in ozone generation efficiency can be suppressed, and nitrogen oxides, which are the cause of corrosion in the path, etc., can be reduced. Then, the depressurization performed by the depressurization unit 5 ends, and the process returns to the adsorption process (step ST03). Figure 2 Step ST01).

[0023] As shown above, if the pressure inside adsorption tower A in the vacuum desorption process is lower than atmospheric pressure, the effects described above can be obtained. However, in order to reliably obtain these effects, the following conditions should also be considered.

[0024] For example, if the nitrogen concentration in adsorption tower A during the adsorption process is set to C1, the pressure in adsorption tower A is set to P1, the nitrogen concentration of the first carrier gas in the first desorption process is set to C2, and the pressure in adsorption tower A during the vacuum desorption process is set to P2, then the pressure in adsorption tower A is reduced until the desired conditions are met. C1×P1≥C2×P2 ・・・(Equation 1) The relationship.

[0025] If the pressure in adsorption tower A is reduced until the relationship shown in Equation 1 is satisfied, reducing the partial pressure (concentration × pressure) of nitrogen in the vacuum desorption step (step ST03) to below the partial pressure of nitrogen in the adsorption step (step ST01), the amount of nitrogen adsorbed in the adsorbent material in adsorption tower A at the end of the desorption step can be reliably reduced compared to the adsorption step. Therefore, the accumulation of nitrogen in adsorption tower A can be reliably reduced, and the amount of NOx gas generated along with the increase of nitrogen in the circulation path 120 in the next adsorption step (step ST01) can be reliably reduced.

[0026] The ozone supply system according to Embodiment 1, as described above, includes: An ozone generator that produces ozone from oxygen supplied from an oxygen source; An adsorption tower that holds an adsorption material for adsorbing ozone generated by the ozone generator, and alternately and repeatedly performs an adsorption process in which ozone is adsorbed onto the adsorption material and a desorption process in which ozone is desorbed from the adsorption material. A circulation path, in the adsorption process, removes oxygen that has not been adsorbed by the adsorption material from the adsorption tower and supplies it to the ozone generator in a circulating manner. First supply unit for first carrier gas; A carrier gas introduction path, wherein the carrier gas is introduced from the first supply section into the adsorption tower during the desorption process; A carrier gas exit path, which, during the desorption process, exits the ozone accompanying the first carrier gas outside the adsorption tower; and The depressurization section, during the desorption process, reduces the pressure until the pressure inside the adsorption tower falls below atmospheric pressure. Therefore, it can suppress the rise in nitrogen concentration inside the adsorption tower.

[0027] Furthermore, the ozone supply method according to Embodiment 1 as described above includes: The adsorption process involves adsorbing the generated ozone by the adsorbent material housed in the adsorption tower, and removing the oxygen that was not adsorbed by the adsorbent material from the adsorption tower. The oxygen that was not adsorbed by the adsorbent material is then introduced back into the ozone generator as a raw material gas to generate ozone again, and the regenerated ozone is supplied to the adsorption tower. A first desorption step, which, after the adsorption step is completed, introduces a first carrier gas into the adsorption tower to desorb the ozone adsorbed on the adsorbent material along with the first carrier gas and export it outside the adsorption tower; and The vacuum desorption process involves reducing the pressure after the first carrier gas is stopped being introduced until the pressure inside the adsorption tower is below atmospheric pressure. Therefore, it can suppress the rise in nitrogen concentration inside the adsorption tower.

[0028] Furthermore, according to the ozone supply method of Embodiment 1 as described above, In the vacuum desorption process, The pressure value inside the adsorption tower during the adsorption process is set as P1. The pressure value inside the adsorption tower in the vacuum desorption process is set to P2. The nitrogen concentration in the adsorption tower during the adsorption process is set as C1. The nitrogen concentration of the first carrier gas in the first desorption step is set to C2. Under the above conditions, the pressure of the adsorption tower is reduced until C1×P1≥C2×P2 is satisfied. Therefore, the nitrogen partial pressure in the vacuum desorption step is reduced until it becomes lower than the nitrogen partial pressure in the adsorption step, so that the amount of nitrogen adsorbed on the adsorbent material is equal to or less, which can suppress the situation where a large amount of nitrogen remains in the adsorption tower.

[0029] Implementation method 2. Figure 3 This is a block diagram illustrating the structure of the ozone supply system involved in Embodiment 2. Figure 4 It means that it was used Figure 3 The flowchart shows the process of the ozone supply method for the ozone supply system. Figure 5 It means that it was used Figure 3 A flowchart of the steps of other ozone supply methods for the ozone supply system shown.

[0030] In the figures, parts identical to those in Embodiment 1 described above are labeled with the same reference numerals and their descriptions are omitted. Figure 3 In the ozone supply system 1, oxygen source 2 serves as a second supply unit. This second supply unit has a nitrogen concentration lower than that of the first carrier gas and supplies oxygen as the second carrier gas. Oxygen source 2 introduces the second carrier gas into adsorption tower A or adsorption tower B, which is in the desorption process, via second carrier gas introduction path 105. Furthermore, a carrier gas switching valve 6 is included, which switches the supply of the first carrier gas and the second carrier gas to adsorption tower A or adsorption tower B, which is in the desorption process.

[0031] Next, the ozone supply method of the ozone supply system of Embodiment 2 as described above will be explained. First, similar to Embodiment 1 above, the adsorption process of adsorption tower A is performed ( Figure 4 Step ST01). Next, in the adsorption tower A undergoing the desorption process, the first supply unit 4 introduces dry air as the first carrier gas via the first carrier gas introduction path 103. The introduced first carrier gas purges the ozone adsorbed on the adsorbent material in the adsorption tower A outward along with the first carrier gas via the carrier gas outlet path 104, thus performing the first desorption process. Figure 4 Step ST02).

[0032] Next, after stopping the introduction of the first carrier gas, oxygen is introduced from oxygen source 2 into adsorption tower A via the second carrier gas introduction path 105 as the second carrier gas. The introduced second carrier gas, via carrier gas outlet path 104, purges the ozone adsorbed on the adsorbent material in adsorption tower A and the first carrier gas remaining in adsorption tower A outwards along with the second carrier gas, performing the second desorption process. Figure 4 Step ST04).

[0033] In this way, the first carrier gas remaining in adsorption tower A and in carrier gas outlet path 104 is replaced by the second carrier gas and purged out of adsorption tower A. Therefore, since the accumulation of nitrogen in adsorption tower A can be reduced, the amount of NOx gas generated, which accompanies the increase in nitrogen in the circulation path 120 during the next adsorption process (step ST01), can be reduced. This suppresses the decrease in ozone generation efficiency and reduces nitrogen oxides, which are a cause of corrosion in pathways, etc. Then, the introduction of the second carrier gas is stopped, and the process returns to the adsorption process (step ST01). Figure 2 Step ST01).

[0034] In addition, other examples of the ozone supply method in Embodiment 2 will be described. After the second desorption step described above and before the adsorption step, a vacuum desorption step is performed (…). Figure 5 In step ST05), after the introduction of the second carrier gas is stopped, the pressure inside the adsorption tower A is reduced through the pressure reducing section 5 via the carrier gas outlet path 104 until the pressure inside the adsorption tower A is lower than atmospheric pressure. At this time, the portion of the first carrier gas and the portion of the second carrier gas remaining in the adsorption tower A that have not been replaced by the second carrier gas are discharged.

[0035] Therefore, by reducing the accumulation of nitrogen in adsorption tower A, the amount of NOx gas generated, which increases with the nitrogen in the circulation path 120 during the next adsorption process (step ST01), can be further reduced. This further suppresses the decrease in ozone generation efficiency and further reduces nitrogen oxides, which contribute to corrosion of pathways, etc. Then, the depressurization performed by the depressurization unit 5 is stopped, and the process returns to the adsorption process (step ST01). Figure 5 Step ST01).

[0036] As shown above, if the pressure inside adsorption tower A in the vacuum desorption process is lower than atmospheric pressure, the effects described above can be obtained. However, in order to reliably obtain these effects, the following conditions should also be considered.

[0037] For example, if the nitrogen concentration in adsorption tower A in the adsorption process is set to C1, the pressure value in adsorption tower A is set to P1, the nitrogen concentration of the first carrier gas in the first desorption process is set to C2, and the pressure value in adsorption tower A in the vacuum desorption process is set to P2, the pressure in adsorption tower A is reduced until the relationship C1×P1≥C2×P2 ･･･(Equation 1) is satisfied.

[0038] If the pressure in adsorption tower A is reduced until the relationship shown in Equation 1 is satisfied, reducing the partial pressure (concentration × pressure) of nitrogen in the vacuum desorption step (step ST03) to below the partial pressure of nitrogen in the adsorption step (step ST01), the amount of nitrogen adsorbed in the adsorbent material in adsorption tower A at the end of the desorption step can be reliably reduced compared to the adsorption step. Therefore, since the accumulation of nitrogen in adsorption tower A can be reliably reduced, the amount of NOx gas generated along with the increase of nitrogen in the circulation path 120 in the next adsorption step (step ST01) can be reliably reduced.

[0039] The ozone supply system according to Embodiment 2, as described above, can achieve the same effects as Embodiment 1 described above, and... A second supply section includes a second carrier gas with a nitrogen concentration lower than that of the first carrier gas. The second supply unit is connected to the carrier gas inlet path via a carrier gas switching valve that switches the supply of the first carrier gas and the second carrier gas to the adsorption tower. The carrier gas outlet path will export the ozone accompanying the second carrier gas to the outside of the adsorption tower during the desorption process. Therefore, it can further suppress the rise in nitrogen concentration inside the adsorption tower.

[0040] Furthermore, the ozone supply method according to Embodiment 2 as described above includes: The adsorption process involves adsorbing the generated ozone by the adsorbent material stored in the adsorption tower and removing the oxygen that was not adsorbed by the adsorbent material from the adsorption tower. The oxygen that was not adsorbed by the adsorbent material is then introduced back into the ozone generator as a raw material gas to generate ozone again, and the regenerated ozone is supplied to the adsorption tower. A first desorption step, which, after the adsorption step is completed, introduces a first carrier gas into the adsorption tower to desorb the ozone adsorbed on the adsorbent material along with the first carrier gas and export it outside the adsorption tower; and In the second desorption step, after the introduction of the first carrier gas is stopped, a second carrier gas with a lower nitrogen concentration than the first carrier gas is introduced to desorb the ozone adsorbed on the adsorption material and export it outside the adsorption tower. The second carrier gas then replaces the first carrier gas remaining in the adsorption tower. Therefore, it can suppress the rise in nitrogen concentration inside the adsorption tower.

[0041] Furthermore, according to the ozone supply method of Embodiment 2 as described above, This includes a vacuum desorption process, which involves reducing the pressure inside the adsorption tower until the pressure drops below atmospheric pressure after the second carrier gas is stopped being introduced. Therefore, it can further suppress the rise in nitrogen concentration inside the adsorption tower.

[0042] Furthermore, according to the ozone supply method of Embodiment 2 as described above, In the vacuum desorption process, The pressure value inside the adsorption tower during the adsorption process is set as P1. The pressure value inside the adsorption tower in the vacuum desorption process is set to P2. The nitrogen concentration in the adsorption tower during the adsorption process is set as C1. Let the nitrogen concentration of the first carrier gas in the first desorption step be C2. Under the above conditions, reduce the pressure in the adsorption tower until C1×P1≥C2×P2 is satisfied. Therefore, the nitrogen partial pressure in the vacuum desorption process is reduced until it becomes lower than the nitrogen partial pressure in the adsorption process, so that the amount of nitrogen adsorbed by the adsorbent material is equal to or less, which can suppress the situation where a large amount of nitrogen remains in the adsorption tower.

[0043] This application describes various exemplary implementation methods and embodiments, but the various features, forms and functions described in one or more embodiments are not limited to the application of a specific embodiment, and can be applied to the embodiment alone or in various combinations.

[0044] Therefore, numerous variations not illustrated can be conceived within the scope of the technology disclosed in this application. For example, this could include variations, additions, or omissions of at least one structural element, or the extraction of at least one structural element and its combination with structural elements of other embodiments.

[0045] Label Explanation 1. Ozone Supply System 101 Ozone Introduction Path 103 First Carrier Gas Introduction Path 104 Carrier Gas Export Path 105 Second Carrier Gas Introduction Path 11 Switching valve 12 Switching valve 120 Loop Path 121 Circulating Blower 122 Buffer Tank 13 Switching valve 14 Switching valve 15 Switching valve 16 Switching valve 17 Switching valve 18 Switching valve 2. Oxygen source 3. Ozone generator 4. First Supply Department 5. Pressure Reduction Section 6. Carrier gas switching valve.

Claims

1. An ozone supply system characterized by comprising: including: an ozone generator that generates ozone from oxygen supplied from an oxygen source; an adsorption tower that houses an adsorbent that adsorbs ozone generated by the ozone generator, and alternately repeats an adsorption process in which ozone is adsorbed to the adsorbent and a desorption process in which ozone is desorbed from the adsorbent; a circulation path that, in the adsorption process, leads oxygen that is not adsorbed by the adsorbent from the adsorption tower to the ozone generator and circulates the oxygen to the ozone generator; a first supply portion of a first carrier gas; a carrier gas introduction path that, in the desorption process, introduces the first carrier gas from the first supply portion into the adsorption tower; a carrier gas discharge path that, in the desorption process, discharges ozone accompanying the first carrier gas from the adsorption tower; and a pressure reduction portion that, in the desorption process, reduces the pressure in the adsorption tower to below atmospheric pressure.

2. The ozone supply system according to claim 1, characterized in that a second supply portion of a second carrier gas having a lower nitrogen concentration than the first carrier gas is included, the second supply portion is connected to the carrier gas introduction path via a carrier gas switching valve that switches the supply of the first carrier gas and the second carrier gas to the adsorption tower, and the carrier gas discharge path discharges ozone accompanying the second carrier gas from the adsorption tower in the desorption process. including:

3. An ozone supply method characterized by comprising: an adsorption process in which an adsorbent housed in an adsorption tower adsorbs generated ozone and oxygen that is not adsorbed by the adsorbent is led from the adsorption tower, the oxygen that is not adsorbed by the adsorbent being introduced again into an ozone generator as a raw material gas, ozone is regenerated, and the regenerated ozone is supplied to the adsorption tower; a first desorption process in which, after the adsorption process, a first carrier gas is introduced into the adsorption tower, ozone adsorbed to the adsorbent is desorbed accompanying the first carrier gas, and is discharged to the outside of the adsorption tower; and a vacuum desorption process in which, after the introduction of the first carrier gas is stopped, the pressure in the adsorption tower is reduced to below atmospheric pressure. including:

4. An ozone supply method characterized by comprising: an adsorption process in which an adsorbent housed in an adsorption tower adsorbs generated ozone and oxygen that is not adsorbed by the adsorbent is led from the adsorption tower, the oxygen that is not adsorbed by the adsorbent being introduced again into an ozone generator as a raw material gas, ozone is regenerated, and the regenerated ozone is supplied to the adsorption tower; a first desorption process in which, after the adsorption process, a first carrier gas is introduced into the adsorption tower, ozone adsorbed to the adsorbent is desorbed accompanying the first carrier gas, and is discharged to the outside of the adsorption tower; and a second desorption process in which, after the introduction of the first carrier gas is stopped, a second carrier gas having a lower nitrogen concentration than the first carrier gas is introduced, ozone adsorbed to the adsorbent is desorbed and discharged to the outside of the adsorption tower, and the first carrier gas remaining in the adsorption tower is replaced with the second carrier gas. ​ 5. The ozone supply method according to claim 4, characterized in that, the vacuum desorption process is performed after the introduction of the second carrier gas is stopped, and the pressure inside the adsorption tower is reduced until it is lower than atmospheric pressure.

6. The ozone supply method according to claim 3 or 5, characterized in that, in the vacuum desorption process, the pressure value inside the adsorption tower in the adsorption process is set to Pl, the pressure value inside the adsorption tower in the vacuum desorption process is set to P2, the nitrogen concentration of the adsorption tower in the adsorption process is set to Cl, the nitrogen concentration of the first carrier gas in the first desorption process is set to C2, and in the above case, the pressure reduction of the adsorption tower is performed until Cl x Pl > C2 x P2 is satisfied.

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