Gas separation device

Abstract

To provide a gas separator which can be reduced in diameter and cost.SOLUTION: A gas separation device 1 includes an adsorption column 10 having at least one adsorption part for adsorbing an adsorbate in a feed gas to obtain a purified gas, a plurality of desorption ports 14a, 14b, 14c provided in the adsorption column 10 and discharging a desorbed gas containing the adsorbate, desorption lines 14a, 14b, 14c for discharging the desorbed gas from the desorption ports 15a, 15b, 15c, and connected to the desorption lines,,, 15a 15b 15c, the adsorption device includes a decompression pump 20 which decompresses the inside of the adsorption tower 10 to desorb the adsorbate adsorbed to the adsorption part, check valves 15a, 15b, and 15c provided in the desorption lines 25a, 25b, and 25c, and desorption line automatic valves 30 which are installed between the check valves 25a, 25b, and 25c and the decompression pump 20, are closed when the adsorbate is adsorbed, and are opened when the adsorbate is desorbed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas separation apparatus for adsorbing and separating predetermined components from various feed gases to obtain purified gases. [Background technology]

[0002] Conventionally, oxygen gas has been used in various industrial applications, and it is known to use a PSA unit as a means for producing oxygen gas. As introduced in the following Non-Patent Document 1 (see URL), for example, a PSA unit is configured to send air, which is a feed gas, into an adsorption tower, separate the nitrogen in the air under pressure using an adsorbent such as zeolite, and efficiently obtain high-purity oxygen, which is a purified gas.

[0003] The adsorption tower is configured as a cylindrical tower with a large diameter so as to enable uniform pressure reduction. However, as the diameter of the adsorption tower increases, although the pressure loss decreases, the installation space becomes larger. For this reason, as disclosed in Patent Document 1, for example, an adsorption section containing the adsorbent is provided in the adsorption tower, air is fed from the bottom, and multiple desorption ports (multiple decompression chambers) are arranged along the direction of air movement to form a multistage structure, and nitrogen is adsorbed in the adsorption section while oxygen is discharged from the top, thereby reducing the diameter of the adsorption tower.

[0004] An adsorption tower with multiple desorption ports has multiple decompression chambers arranged in multiple stages and multiple desorption ports, allowing for uniform pressure reduction without increasing the diameter of the adsorption tower. In this type of adsorption tower, air is introduced from the bottom, and nitrogen is adsorbed in the adsorption section (adsorption process). Unadsorbed gas (oxygen) is discharged and recovered from the upper opening. Pipes equipped with automatic valves (solenoid valves) that open and close are connected to the multiple desorption ports, and the automatic valves are closed during the adsorption process.

[0005] When the adsorption step is completed, the on-off valve is opened, the pressure inside the adsorption tower is reduced through piping by a vacuum pump (decompression pump), and the desorbed gas (nitrogen) adsorbed in the adsorption section is sucked through multiple desorption ports (desorption step). By repeating the above-mentioned adsorption and desorption steps, it is possible to continuously obtain purified oxygen gas. [Prior art documents] [Patent documents]

[0006] [Non-Patent Document 1] https: / / www.veolia.jp / ja / our-services / industrial / epc / psa-vsa-oxygen-generators [Patent Document 1] Patent No. 4589049 Summary of the Invention [Problem to be solved by the invention]

[0007] The multistage gas separation apparatus (PSA apparatus) described in Patent Document 1 requires the installation of an automatic valve that opens and closes at each desorption port, resulting in high costs. Specifically, automatic valves must be installed at the desorption ports because, when air from which nitrogen has been desorbed in the adsorption section flows through the desorption section, the oxygen from which the nitrogen has been removed also flows out (this is undesirable in the adsorption process). Furthermore, if the desorption section is not sufficiently sealed, gas may reflux into the adsorption tower. In this case, the cost increases dramatically as the number of desorption ports increases.

[0008] Furthermore, gas separation equipment (PSA equipment) aims to effectively discharge adsorbed gases by increasing the installation surface area of ​​the adsorbent installed inside the equipment, so the equipment tends to be larger in diameter, which results in the need for a large installation space.

[0009] As described above, the conventional technology does not allow for a reduction in the diameter and cost of the gas separation device.

[0010] An object of the present invention is to provide a gas separation device that can be made smaller in diameter and at lower cost. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, the gas separation apparatus of the present invention is characterized by comprising: an adsorption tower having at least one adsorption section that adsorbs adsorbates in a supply gas to produce a purified gas; a plurality of desorption ports provided in the adsorption tower and discharging a desorbed gas containing the adsorbates; a desorption line that discharges the desorbed gas from the desorption port; a pressure reduction pump connected to the desorption line and reducing the pressure inside the adsorption tower to desorb the adsorbates adsorbed in the adsorption section; a check valve provided in the desorption line; and an automatic desorption line valve installed between the check valve and the pressure reduction pump that closes when the adsorbates are adsorbed and opens when the adsorbates are desorbed.

[0012] In the gas separation apparatus having the above-described configuration, by providing multiple desorption ports in the adsorption tower for discharging the desorbed gas, uniform pressure reduction can be achieved even when the diameter of the adsorption tower is reduced, thereby enabling the apparatus to be made more compact. Furthermore, by providing a decompression pump for reducing the pressure inside the adsorption tower in the desorption line that discharges the desorbed gas from the desorption ports, and by providing check valves in all or part of the desorption ports (desorption lines), and by providing an automatic desorption line valve that opens and closes the suction operation between the check valves and the decompression pump, it is no longer necessary to provide an automatic valve for each desorption port, thereby reducing costs. [Effects of the Invention]

[0013] According to the present invention, a gas separation device that can be made smaller in diameter and at lower cost can be obtained. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing a first embodiment of a gas separation device. [Figure 2] FIG. 2 is a diagram showing an adsorption process in the gas separation apparatus shown in FIG. [Figure 3] FIG. 2 is a diagram showing a desorption process when assembled into the gas separation apparatus shown in FIG. [Figure 4] FIG. 10 is a diagram showing a modification of the first embodiment. [Figure 5] FIG. 2 is a schematic diagram showing a second embodiment of a gas separation device. [Figure 6] FIG. 4 is a schematic diagram showing a third embodiment of a gas separation device. [Figure 7] 10A and 10B are schematic diagrams showing a fourth embodiment (multi-stage adsorption tower) of a gas separation apparatus, in which (a) is a plan view showing the configuration of the first stage, and (b) is a plan view showing the configuration of the second and upper stages. [Figure 8] FIG. 10 is a schematic diagram showing a fifth embodiment (multiple adsorption towers) of a gas separation apparatus, showing a state in which an adsorption step is performed in the left adsorption tower and a desorption step is performed in the right adsorption tower. [Figure 9] FIG. 9 is a diagram showing the state in which the desorption step is performed in the left adsorption tower and the adsorption step is performed in the right adsorption tower in the configuration shown in FIG. 8. [Figure 10] FIG. 10 is a schematic diagram showing a sixth embodiment of a gas separation device. [Figure 11] FIG. 10 is a schematic diagram showing a seventh embodiment of a gas separation device. [Figure 12] FIG. 13 is a schematic diagram showing a modified example of the seventh embodiment of the gas separation device. DETAILED DESCRIPTION OF THE INVENTION

[0015] In the following embodiments, a PSA (Pressure Swing Adsorption) oxygen gas generator, which is a type of apparatus that supplies air (feed gas), adsorbs and removes nitrogen (adsorbate), and obtains highly concentrated oxygen (purified gas), will be described as an example of a gas separation apparatus. The gas separation apparatus illustrated in the following description is shown schematically with its characteristic adsorption tower and a line (such as a tubular pipe) connected to the adsorption tower through which the gas passes.

[0016] [First embodiment] 1 to 3 are diagrams showing a first embodiment. The gas separation apparatus 1 of this embodiment includes a blower 2 and a substantially cylindrical adsorption tower 10 to which air, which is a feed gas, is supplied via a supply line 3. The supply line 3 is connected to a supply port 10a provided at the bottom of the adsorption tower 10, and an adsorption section 12 is provided inside the adsorption tower 10 to adsorb nitrogen, which is an adsorbate in the feed gas, and convert it into oxygen. In addition, an outlet 10b is provided at the top of the adsorption tower 10, through which purified gas (oxygen) from which the adsorbates have been removed by the adsorption section 12 is discharged, and an exhaust line 11 is connected to the outlet 10b.

[0017] The adsorption section 12 includes an adsorbent such as zeolite that adsorbs nitrogen, and in this embodiment, it is installed at multiple locations (in this embodiment, adsorption sections 12a and 12b are installed at two locations along the air flow direction) on the air movement path within the adsorption tower 10. When the air comes into contact with this adsorbent, mainly nitrogen is removed, and the air becomes highly concentrated oxygen.

[0018] A first gap S1 is formed between the plurality of adsorption sections 12a, 12b, an inlet-side gap Sa is formed between the adsorption section 12a and the lower inner wall 10c of the adsorption tower, and an outlet-side gap Sb is formed between the adsorption section 12b and the upper inner wall 10d of the adsorption tower. Furthermore, the adsorption tower 10 has a plurality of desorption ports 14a, 14b, and 14c provided in the side wall of the adsorption tower 10 at portions corresponding to the gaps Sa, S1, and Sb so as to discharge desorbed gas containing nitrogen adsorbed in each adsorption section. These desorption ports 14a, 14b, and 14c are arranged in multiple stages (three stages in this embodiment) within the adsorption tower 10 along the direction in which the supply gas flows (from bottom to top in this embodiment) by the blower 2. It is also possible to provide only one suction portion 12 and only gaps Sa and Sb, or to provide three or more suction portions.

[0019] An inlet-side desorption line 15a, a first desorption line 15b, and an outlet-side desorption line 15c extend from the desorption ports 14a, 14b, and 14c, respectively, and discharge the desorbed gas from the adsorption section 12. The first desorption line 15b merges with the outlet-side desorption line 15c at a junction B and is connected to a junction desorption line 15d. The inlet-side desorption line 15a merges with the junction desorption line 15d at a junction A and is connected to the desorption line 15.

[0020] The desorption line 15 is equipped with a decompression pump 20 that reduces the pressure inside the adsorption tower 10. The inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c are equipped with check valves 25a, 25b, and 25c. The check valves 25a, 25b, and 25c are designed to prevent backflow by allowing the desorbed gas from each desorption port to flow in only one direction (toward the decompression pump) when the decompression pump 20 reduces the pressure inside the adsorption tower 10. The check valves 25a, 25b, and 25c are installed in the inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c, respectively. When the decompression pump 20 draws air, the inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c become negative pressure, causing the check valves to open due to the pressure difference between the adsorption tower side and the inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c.

[0021] Further, the desorption line 15 is provided with a first automatic valve (desorption line automatic valve) 30 which is opened and closed by an electric signal.

[0022] As shown in Fig. 1, the supply line 3 is provided with a second automatic valve (automatic supply line valve) 31 that controls the supply of air, which is the supply gas, to the adsorption tower 10, and the discharge line 11 is provided with a third automatic valve (automatic discharge line valve) 32 that controls the discharge of oxygen, which is the purified gas, from the adsorption tower 10. In Fig. 1, the first automatic valve 30, the second automatic valve 31, and the third automatic valve 32 are shown in an open state, but in the actual adsorption process and desorption process, the open / closed state of each automatic valve is controlled as follows.

[0023] Next, the operation of the gas separation apparatus 1 equipped with the above-described adsorption tower 10 will be described. Supply gas (air) pressurized by a blower 2 is supplied to the adsorption tower 10 via a supply line 3, and the highly concentrated oxygen (purified gas) obtained after the nitrogen (adsorbate) in the supply air is adsorbed by the adsorption section 12 is discharged from an exhaust line 11 via an exhaust port 10b provided at the top of the adsorption tower 10.

[0024] 2 shows the adsorption step (generation of purified gas), in which the second automatic valve 31 and the third automatic valve 32 are "opened" and the first automatic valve 30 is "closed," so that air moves from the bottom to the top of the adsorption tower 10 while nitrogen is adsorbed, and oxygen from which nitrogen has been removed is obtained via the discharge line 11. Although some of the gas may flow into the desorption line 15, because the first automatic valve 30 is "closed," the gas remains stagnant in the desorption line 15, the inlet-side desorption line 15a, the first desorption line 15b, and the outlet-side desorption line 15c.

[0025] After a certain time has elapsed since the adsorption step shown in Fig. 2, the desorption step (nitrogen gas separation) is performed as shown in Fig. 3. In this desorption step, the second automatic valve 31 and the third automatic valve 32 are closed, the first automatic valve 30 is opened, and the decompression pump 20 is driven to reduce the pressure inside the adsorption tower 10 via the desorption line 15, the inlet desorption line 15a, the first desorption line 15b, the outlet desorption line 15c, and the combined desorption line 15d, thereby desorbing the desorbed gas containing nitrogen adsorbed by the adsorbent in the adsorption section 12. This desorbed gas is discharged from the gaps Sa, S1, and Sb inside the adsorption tower 10 to the outside of the gas separation apparatus 1 via the desorption ports 14a, 14b, and 14c, the inlet desorption line 15a, the first desorption line 15b, the outlet desorption line 15c, the combined desorption line 15d, and the desorption line 15.

[0026] According to this embodiment, multiple adsorption sections 12 and gaps S are provided within the adsorption tower 10 along the direction of supply gas movement, so that the discharge of desorbed gas is not hindered even when the diameter of the adsorption tower is reduced. Furthermore, check valves 25a, 25b, and 25c are provided in the inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c, and the inlet desorption line 15a, the first desorption line 15b, and the outlet desorption line 15c are connected to the combined desorption line 15d and the desorption line 15. Adsorption and desorption are switched by opening and closing the single first automatic valve 30 provided only on the desorption line 15. This configuration allows for fewer automatic valves to be installed than in the past, thereby reducing costs.

[0027] As shown in the modified example of Fig. 4, the desorption line 15 may not be connected to the junction A shown in Figs. 1 to 3, but may branch off from a junction desorption line 15d located upstream of the junction A and downstream of the junction B. Alternatively, the desorption line 15 may branch off from the outlet desorption line 15c located upstream of the junction B and downstream of the check valve 25c. In this configuration, the difference in distance between the decompression pump 20 and each gap (Sa, S1, Sb) inside the adsorption tower 10 is smaller than in the configurations shown in Figs. 1 to 3, making it easier to decompress all of the gaps (Sa, S1, Sb) when decompressing with the decompression pump.

[0028] Next, another embodiment of the present invention will be described. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0029] [Second embodiment] FIG. 5 is a diagram showing a second embodiment. In the adsorption tower 10 of the first embodiment described above, check valves are provided at all desorption ports, but a configuration may be adopted in which check valves are not provided at some of the desorption ports.

[0030] Specifically, check valves are provided in the desorption lines (in this embodiment, desorption lines 15b and 15c) other than the inlet desorption line 15a at the most upstream side in the direction in which the supply gas flows within the adsorption tower 10, and no check valve is provided in the inlet desorption line 15a at the most upstream side.

[0031] If a check valve is not provided in the most upstream inlet desorption port 14a (inlet desorption line 15a), gas may flow into the inlet desorption line 15a during the adsorption process, but the check valves 25b and 25c prevent the gas from returning to the adsorption tower 10. Furthermore, the inlet desorption port 14a, which is located at a position corresponding to the inlet gap Sa, is located close to the decompression pump 20, which facilitates decompression of the inlet gap Sa by operating the decompression pump 20. Therefore, during the desorption process, the desorbed gas is less likely to backflow in the inlet desorption line 15a than in the first desorption line 15b and the outlet desorption line 15c.

[0032] [Third embodiment] FIG. 6 is a diagram showing a third embodiment. In the second embodiment described above, no check valve is provided in the inlet side detachment line 15a, but in this embodiment, a configuration is adopted in which a fluid resistance means 40 is provided without providing a check valve.

[0033] As in the second embodiment described above, if a check valve is not installed in the inlet side desorption line 15a, gas will flow more easily, which may make it difficult for the pressure reducing pump 20 to reduce the pressure in the first desorption line 15b, the outlet side desorption line 15c, the first gap S1, and the outlet side gap Sb during the desorption process.

[0034] The check valves 25b and 25c open to allow gas to flow when a certain pressure difference occurs between the adsorption tower 10 and the decompression pump 20. When the decompression pump 20 is suctioning, the check valves open appropriately so that the flow rates of the fluid flowing through the line without a check valve in the desorption line 15 and the fluid flowing through the line with a check valve are the same (equal suction), which makes it possible to suction nitrogen evenly from all the desorption ports.

[0035] In this embodiment, a fluid resistance means 40 that applies resistance to the gas flow is installed in the inlet side desorption line 15a.

[0036] This fluid resistance means 40 should be configured to provide pressure resistance equivalent to that of the check valves 25b, 25c installed in the first desorption line 15b and the outlet side desorption line 15c, and to be able to suck in a similar amount of gas when sucked by the pressure reducing pump 20.

[0037] The fluid resistance means 40 can be configured, for example, by installing an orifice inside the tubular body that is the inlet side desorption line 15a, by narrowing the inner diameter of the inlet side desorption line 15a into a funnel shape, by making the inner diameter of the piping of the inlet side desorption line 15a smaller than the inner diameters of the other first desorption line 15b and the outlet side desorption line 15c (reducing the range through which gas passes), or by increasing the flow resistance inside the tubular body.

[0038] As a result, when suction is performed by the decompression pump 20, the check valves 25b and 25c open appropriately, making it possible to suction the desorbed gas almost uniformly from the desorption ports 14a, 14b, and 14c.

[0039] [Fourth embodiment] FIG. 7 is a diagram showing a fourth embodiment. As described above, the fluid resistance means 40 has a structure in which the inlet-side desorption line 15a has a different configuration from the other first desorption line 15b and the outlet-side desorption line 15c. However, in the present embodiment, when the adsorption tower 10 is configured as a multi-stage adsorption tower with multiple desorption ports and desorption ports are formed around each stage, it is possible to use a configuration such as that shown in FIG. 7.

[0040] In the configuration shown in Fig. 7, the number of detachment ports without check valves is configured to be less than the number of detachment ports with check valves. Specifically, in the inlet-side gap Sa, as shown in Fig. 7(a), the number of inlet-side detachment ports 14a without check valves is two, and in the first gap S1 (the outlet-side gap Sb is configured similarly), the number of first detachment lines 15b with check valves 25b is three, as shown in Fig. 7(b).

[0041] In this way, with regard to the fluid resistance means 40 shown in Figure 6, by configuring the number of inlet side detachment ports 14a to be less than the number of other detachment ports 14b (14c), the flow of gas is restricted (pressure resistance is imparted) even if the inlet side detachment line 15a is made into a tubular body of the same diameter as the first detachment line 15b and the outlet side detachment line 15c.

[0042] The number of the inlet-side attachment / detachment openings 14a may be one, but providing two or more will allow the attachment / detachment process to be carried out smoothly. The number of attachment / detachment openings on the second and subsequent stages is not limited as long as it is greater than the number of attachment / detachment openings on the first stage.

[0043] [Fifth embodiment] 8 and 9 are diagrams showing a fifth embodiment. The gas separation apparatus of the present invention may include two or more adsorption towers, and in this embodiment includes two adsorption towers 10A and 10B.

[0044] In this case, each adsorption tower is configured to alternately and continuously perform the adsorption process and the desorption process. That is, while the adsorption process is being performed in the left adsorption tower 10A, the desorption process is being performed in the right adsorption tower 10B (see FIG. 8), and while the desorption process is being performed in the left adsorption tower 10A, the adsorption process is being performed in the right adsorption tower 10B (see FIG. 9).

[0045] The adsorption towers 10A and 10B, which are installed side by side, have two desorption ports 14a and 14b along the flow direction of the supply gas, with one adsorption section 12 provided between them. Therefore, the adsorption towers 10A and 10B have the same configuration and are provided with an inlet-side gap Sa and an outlet-side gap Sb along the vertical direction.

[0046] The lower part of each of the adsorption towers 10A and 10B is connected to a blower 2 that sends a supply gas to the supply port 10a, and a supply line 3 that branches off from each of the supply ports of the adsorption towers is connected to the supply line 3. That is, the supply line 3 has branch supply lines 3A and 3B corresponding to each of the adsorption towers, and second automatic valves 31A and 31B are provided on each of the branch supply lines 3A and 3B. In addition, the upper part of each of the adsorption towers is provided with branch discharge lines 11A and 11B that branch off from a discharge line 11 that discharges the purified gas via a discharge port 10b. Third automatic valves 32A and 32B are provided on these branch discharge lines 11A and 11B.

[0047] The adsorption towers 10A and 10B are provided with branch desorption lines 15A and 15B branching off from the desorption line 15, and first automatic valves 30A and 30B are disposed therein.

[0048] In a gas separation apparatus configured as described above, while an adsorption step is being performed in one adsorption tower, a desorption step can be performed in the other adsorption tower, enabling the purified gas (oxygen) to be continuously discharged. That is, as shown in Fig. 8, while an adsorption step (gas purification) is being performed in the left adsorption tower 10A, a desorption step can be performed in the right adsorption tower 10B.

[0049] Specifically, the second automatic valve 31A and the third automatic valve 32A of the left adsorption tower 10A are opened, and the first automatic valve 30A is closed, and air is supplied from the blower 2. In addition to this supply, the second automatic valve 31B and the third automatic valve 32B of the right adsorption tower 10B are closed, and the first automatic valve 30B is opened, and suction is performed by the decompression pump 20, thereby enabling the adsorption process to be performed in the left adsorption tower 10A and the desorption process to be performed in the right adsorption tower 10B.

[0050] 9, the second automatic valve 31A and the third automatic valve 32A of the left adsorption tower 10A are closed and the first automatic valve 30A is open to supply air from the blower 2. Simultaneously with this supply, the second automatic valve 31B and the third automatic valve 32B of the right adsorption tower 10B are opened and the first automatic valve 30B is closed, and suction is performed with the decompression pump 20, thereby enabling the desorption process to be performed in the left adsorption tower 10A and the adsorption process to be performed in the right adsorption tower 10B.

[0051] [Sixth embodiment] FIG. 10 is a diagram showing a state during a detaching step in the sixth embodiment. With this configuration, during the desorption step, the pressure inside the adsorption tower 10C is reduced by driving the decompression pump 20, and a purge gas is introduced into the adsorption section, thereby facilitating desorption of the desorbed gas adsorbed in the adsorption section. In this embodiment, a purified gas (oxygen in this embodiment) is used as the purge gas, and preferably, a portion of the oxygen discharged into the discharge line 11 via the discharge port 10b is introduced (refluxed) into the adsorption tower 10C. Note that the purge gas may also be introduced into the adsorption tower 10C from a dedicated reservoir.

[0052] The adsorption tower 10C of this embodiment is provided with multiple (three) adsorption sections 12a, 12b, and 12c along the flow direction of the supply gas, and at least one gap (an inlet gap Sa, a first gap S1, a second gap S2, and an outlet gap Sb) is provided adjacent to each adsorption section. Therefore, the first gap S1 is adjacent to the adsorption sections 12a and 12b, and the second gap S2 is adjacent to the adsorption sections 12b and 12c.

[0053] A purge port 51a is provided in the wall of the adsorption tower 10C at a portion corresponding to the first gap S1, and is connected to a purge gas supply line 50. Meanwhile, desorption ports 14a and 14b are provided in the walls of the adsorption tower 10C that form the inlet gap Sa and the second gap S2, respectively. The desorption ports 14a and 14b are connected to an inlet desorption line 15a and a first desorption line 15b, respectively.

[0054] As described below, no desorption port is installed in the wall of the adsorption tower 10C corresponding to the outlet side gap Sb and the gap (first gap S1) where the purge port 51a is installed, simplifying the overall structure compared to other embodiments.

[0055] As in the previous embodiment, the feed gas supplied through the supply line 3 in the adsorption process is supplied from the feed port 10a of the inlet side gap Sa, and as it moves toward the discharge port 10b, nitrogen is removed and the purified gas is discharged from the discharge port 10b provided in the wall of the adsorption tower 10C at a position corresponding to the outlet side gap Sb.

[0056] In the desorption step, the purge gas is returned to the adsorption tower from a reservoir (not shown) that stores the purified gas discharged through the discharge line 11 via a purge gas supply line 50. The supply of the purge gas is controlled to be on or off by an automatic valve (purge gas supply line automatic valve) 51 provided on the purge gas supply line 50.

[0057] By driving the decompression pump 20, the pressure inside the adsorption tower 10C is reduced via the desorption line 15, the inlet desorption line 15a, and the first desorption line 15b, so that the purge gas supplied to the first gap S1 flows into the adsorption sections 12a and 12b, thereby promoting the desorption of the desorbed gas containing nitrogen adsorbed in the adsorption process.

[0058] The purge port 51a for supplying the purge gas is installed in the wall of the adsorption tower 10C corresponding to the gap (first gap S1 in this embodiment) where the desorption ports 14a and 14b are not installed, excluding the outlet-side gap Sb. The purpose of the purge gas is to flow into the adsorption section adjacent to the gap where the purge port 51a is installed to promote desorption of the desorbed gas, so it is not necessary to install the purge port and the desorption port in the same gap. Furthermore, since the outlet-side gap Sb is filled with the purified gas purified in the adsorption process, there is no need to supply the purge gas to the outlet-side gap Sb.

[0059] The above-described purge port may be provided in at least one of the walls forming at least one gap in the adsorption tower. In particular, providing a purge port in a gap between adjacent adsorption sections can efficiently enhance the desorption effect.

[0060] The gas separation apparatus of this embodiment may include two or more adsorption towers, and each adsorption tower may be configured to alternately and continuously perform the adsorption step and the desorption step.

[0061] [Seventh embodiment] FIG. 11 is a diagram showing a state during a detaching step in the seventh embodiment. In this embodiment, five (five stages) adsorption sections 12a to 12e are provided along the flow direction of the supply gas, and at least six gaps (inlet side gap Sa, first gap S1, second gap S2, third gap S3, fourth gap S4, and outlet side gap Sb) are provided adjacent to each adsorption section from the supply port 10a to the exhaust port 10b.

[0062] In this configuration, purge ports 51a, 52a are provided in the first gap S1 and the third gap S3, and automatic valves (purge gas supply line automatic valves) 51, 52 provided in the supply lines 50a, 50b of the purge gas supply line 50 are used to control the supply and stop of purge gas to each gap. In this manner, an odd number of adsorption sections (three, five, seven, etc.) are provided, and gaps are provided on both sides to offset the purge ports and desorption ports. A purge port and a desorption port are not both provided in the same gap on the wall of the adsorption tower 10D (e.g., a desorption port is provided in the inlet gap, a purge port in the gap above that, a desorption port in the gap above that, etc.). This allows the configuration of the sixth embodiment to be further multi-staged, thereby more efficiently promoting the desorption effect.

[0063] FIG. 12 is a schematic diagram showing a modification of the seventh embodiment. As shown in this modified example, the valves arranged in the supply lines 50a, 50b connected to the purge ports 51a, 52a can be constructed of check valves 58, 59, and an automatic valve (purge gas supply line automatic valve) 55 can be arranged in the purge gas supply line 50. In this configuration, when the suction portions are formed in multiple stages, it is possible to reduce the cost.

[0064] The gas separation apparatus of this embodiment may be configured to include two or more adsorption towers, and each adsorption tower may be configured to alternately and continuously perform the adsorption step and the desorption step.

[0065] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified in various ways. In the gas separation apparatus of the present invention, the feed gas and purified gas are not limited to the air and oxygen described above. Furthermore, the configuration of the adsorption tower and the number of desorption ports can be modified as appropriate, and the components of the above-described embodiment can be combined as appropriate. [Explanation of symbols]

[0066] 1 Gas separation device 2 blowers 10, 10A, 10B Adsorption tower 12(12a~12e) Adsorption part 14a,14b,14c Detachment port 15 Desorption line 15a Inlet side desorption line 15b First Desorption Line 15c Exit side detachment line 15d Joint Desorption Line 20. Decompression pump 25a, 25b, 25c check valve 30 First automatic valve (detachment line automatic valve) 31 Second automatic valve (supply line automatic valve) 32 Third automatic valve (discharge line automatic valve) 51a, 52a Purge port 51, 52, 55 Automatic valve (purge gas supply line automatic valve) A,B confluence Sa Inlet side gap S1 First gap S2 Second gap S3 Third gap Sb Outlet side gap

Claims

1. an adsorption tower having at least one adsorption section for adsorbing adsorbates in the feed gas to produce a purified gas; a plurality of desorption ports provided in the adsorption tower for discharging a desorbed gas containing the adsorbate; a desorption line that discharges the desorbed gas from the desorption port; a decompression pump connected to the desorption line, which decompresses the interior of the adsorption tower to desorb the adsorbate adsorbed in the adsorption section; a check valve provided in the detachment line; an automatic desorption line valve that is installed between the check valve and the decompression pump and that closes when the adsorbate is adsorbed and opens when the adsorbate is desorbed; A gas separation device comprising:

2. the adsorption tower has a supply port for supplying the supply gas and a discharge port for discharging the purified gas, 2. The gas separation apparatus according to claim 1, wherein the interior of the adsorption tower has an inlet gap on the supply port side and an outlet gap on the discharge port side.

3. 3. The gas separation apparatus according to claim 2, wherein the adsorption tower has the desorption port formed in each of the walls that define the inlet-side gap and the outlet-side gap.

4. A plurality of adsorption sections are provided in the adsorption tower, 3. The gas separation device according to claim 2, wherein at least one gap is provided between the inlet-side gap and the outlet-side gap.

5. The gas separation device according to claim 4, characterized in that the adsorption tower has the desorption port formed in at least two of the walls forming the inlet side gap, the outlet side gap, and the at least one gap.

6. 2. The gas separation apparatus according to claim 1, wherein the check valve is provided in a desorption line of a desorption port other than the desorption port located most upstream in the direction of flow of the supply gas in the adsorption tower.

7. 7. The gas separation apparatus according to claim 6, wherein a fluid resistance means is provided in the desorption line of the most upstream desorption port.

8. 8. The gas separation apparatus according to claim 7, wherein the fluid resistance means has a structure that provides a passage range that is smaller than the passage range of the desorbed gas sucked through the desorption port provided with the check valve.

9. The adsorption tower is configured as a multi-stage tower having a plurality of desorption ports, 9. The gas separation apparatus according to claim 8, wherein the number of desorption ports in the stage not provided with the check valve is smaller than the number of desorption ports in the stage provided with the check valve.

10. the number of attachment / detachment ports in the stage not provided with the check valve is plural, 10. The gas separation apparatus according to claim 9, wherein the number of desorption ports in the stage provided with the check valve is greater than the number of desorption ports in the stage not provided with the check valve.

11. The adsorption tower is provided in a plurality of columns, each adsorption tower comprises a supply line connected to a blower that feeds the supply gas and branching off for each adsorption tower; an automatic supply line valve provided on the supply line for each adsorption tower; a discharge line that discharges the purified gas from each adsorption tower; and an automatic discharge line valve provided on the discharge line for each adsorption tower; 2. The gas separation apparatus according to claim 1, wherein the desorption line is branched for each adsorption tower, and the automatic valve is provided for each branched desorption line.

12. The gas separation apparatus according to claim 11, wherein the automatic supply line valves and the automatic discharge line valves of each of the adsorption towers are controlled to open and close so that an adsorption process is performed in one or more of the adsorption towers and a desorption process is performed in one or more of the adsorption towers.

13. 5. The gas separation apparatus according to claim 4, wherein the adsorption tower has a purge port for supplying a purge gas formed in at least one of the walls forming the at least one gap.

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