Gas refining apparatus

Abstract

To obtain a gas refining apparatus that can suppress energy consumption during operation, while downsizing the housing.SOLUTION: A gas refining apparatus 10 comprises: a pump body 12 including an introduction port 14 through which a mixed gas is introduced, a first lead-out port 16 through which refined gas is lead out, and a second lead-out port 18 through which a second gas is lead out; an inner rotor 40 which is provided inside an outer rotor 30, forms a gas storage part R1 between itself and the outer rotor 30, and repeats increase and decrease of capacity of a gas storage part R2 according to drive; and an adsorption part 50 which is provided on at least a part of a lateral face of the gas storage part R2, and is capable of adsorbing the second gas by approaching with the mixed gas.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a gas purification device. [Background technology]

[0002] Patent Document 1 describes a technology for separating specific substances from the gas or powder to be treated by bringing the gas or powder into contact with the surface of a rotating body, adsorbing the specific substance onto the surface of the rotating body, and recovering it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-171760 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes an air treatment device that brings indoor air into contact with a disc-shaped rotor to adsorb harmful substances. In this air treatment device, the rotor is formed by impregnating a porous substrate with a scavenger that captures harmful substances. Harmful substances are captured as indoor air passes through the rotor. In other words, the rotor acts as an indoor air filter. This creates a problem: the rotor experiences significant pressure loss due to contact with indoor air, resulting in increased energy consumption for motors and other driving sources. Furthermore, because gas passing through the rotor encounters significant resistance from the rotor, ensuring sufficient gas flow requires a larger housing that forms the gas flow path.

[0005] The inventors of the present application have devised a method for separating a predetermined gas from a mixed gas containing two or more gases to obtain a purified gas by rotating a rotor inside a housing into which the mixed gas is introduced and adsorbing the predetermined gas onto the surface of the rotor. Even in this case, the same problems as those in Patent Document 1 arise.

[0006] In consideration of the above, an object of the present invention is to provide a gas purification device that can reduce the energy consumption during operation while reducing the size of the housing. [Means for solving the problem]

[0007] The gas purification device described in claim 1 is a gas purification device that separates a second gas from a mixed gas containing at least a first gas and a second gas, and delivers a purified gas in which the concentration of the first gas has been increased, and comprises: a housing having an inlet through which the mixed gas is introduced, a first outlet through which the purified gas is delivered, and a second outlet through which the second gas is delivered; a driver provided inside the housing, forming a gas storage section between the housing and the driver and repeatedly increasing and decreasing the volume of the gas storage section when driven; and an adsorption section provided on at least a portion of the side of the gas storage section, capable of adsorbing the second gas by contact with the mixed gas.

[0008] In the gas purification device described in claim 1, the driver is driven inside the housing, causing the volume of the gas storage section formed between the housing and the driver to repeatedly increase and decrease. As a result, the mixed gas introduced through the inlet is forced to flow inside the gas storage section as the volume increases and decreases, achieving a flow rate that allows the mixed gas to be discharged through the first outlet or the second outlet. Furthermore, an adsorption section provided on the side of the gas storage section comes into contact with the mixed gas and adsorbs the second gas contained in the mixed gas. As a result, the second gas is separated from the mixed gas within the gas storage section, and a purified gas with an increased concentration of the first gas is stored within the gas storage section. The purified gas can then be discharged through the first outlet provided in the housing.

[0009] In this way, in the gas purification device described in claim 1, the mixed gas stored in the gas storage unit attains a predetermined flow rate by driving the driver, and at the same time, the second gas contained in the mixed gas is separated by the adsorption action of the adsorption unit. Therefore, compared to a structure in which an adsorption filter is installed in the mixed gas flow path, energy consumption during operation of a drive source such as a motor is reduced. Furthermore, because the mixed gas attains a predetermined flow rate, a sufficient amount of gas can be ensured, allowing for a more compact housing.

[0010] A gas purification device according to a second aspect of the present invention has the configuration according to the first aspect, wherein the driver is configured to pressurize the inside of the gas storage portion when the volume of the gas storage portion decreases.

[0011] In the gas purification device according to claim 2, the driver is configured to pressurize the gas storage section when the volume of the gas storage section decreases, thereby increasing the contact efficiency between the adsorption section and the mixed gas and improving the adsorption performance of the second gas.

[0012] The gas purification device described in claim 3 is a trochoid pump type gas purification device in the configuration described in claim 1 or claim 2, wherein the housing is a cylindrical pump body and an outer rotor that is accommodated in the pump body and rotatably supported, and has a plurality of external teeth protruding from its inner surface, the driver is an inner rotor that protrudes from the outer surface of the driver and has a plurality of internal teeth circumscribing the external teeth, has a rotation axis that is eccentric with respect to the outer rotor, and is configured so that rotation around the rotation axis repeatedly increases and decreases the volume of the gas storage section formed between the external teeth and the internal teeth, and the adsorption section is provided on all or part of at least one of the inner surface of the housing and the outer surface of the driver.

[0013] The gas purification device described in claim 3 is a trochoid pump type gas purification device, and therefore a gas reservoir is formed between the outer rotor as a housing and the inner rotor as a driver. The phase difference between the rotation of the inner rotor and the outer rotor causes the volume of the gas reservoir to repeatedly increase and decrease, thereby achieving a predetermined flow rate for the mixed gas and simultaneously separating the second gas that has come into contact with the adsorption section. This makes it possible to obtain purified gas from the mixed gas using a trochoid pump, which is well known for its structure, for example, in vehicle oil pumps.

[0014] The gas purification device described in claim 4 is configured in the configuration described in claim 3, wherein the gas storage section is pressurized by introducing the mixed gas through the inlet and is depressurized by stopping the introduction of the mixed gas through the inlet, and the adsorption section is configured to desorb the second gas by depressurizing the gas storage section.

[0015] In the gas purification device described in claim 4, by stopping the introduction of the mixed gas through the inlet, the pressure inside the gas storage section can be reduced and the second gas can be desorbed from the adsorption section, thereby simplifying the regeneration cycle of the adsorption section.

[0016] The gas purification device described in claim 5 has the configuration described in claim 3, and further includes a heating section provided on one axial side of the pump body, which heats one axial side of the gas storage section to a specific temperature or higher and generates an airflow within the gas storage section from one axial direction to the other, and the inlet, the first outlet, and the heating section are arranged in this order along the circumferential direction of the outer rotor on one axial side of the pump body, and the second outlet is arranged on the other axial side of the pump body at a position overlapping with the heating section when viewed in the axial direction, and the adsorption section is configured to adsorb the second gas below a specific temperature and desorb the second gas at a temperature above the specific temperature, and desorbs the second gas when the gas storage section passes through the heating section.

[0017] In a gas purification device described in claim 5, an inlet, a first outlet, and a heating unit are arranged in this order along the circumferential direction of the outer rotor on one axial side of the pump body. Therefore, the gas storage unit passes through the inlet, the first outlet, and the heating unit in this order as the inner rotor rotates. The gas storage unit adsorbs a second gas from the mixed gas while moving from the inlet to the first outlet, generating a purified gas. The gas storage unit then discharges the purified gas as it passes through the first outlet, and passes through the heating unit with the second gas adsorbed by the adsorption unit. Within the gas storage unit that has passed through the heating unit, an airflow is generated from one axial direction of the pump body to the other, and the second gas desorbed from the adsorption unit on this airflow flows toward the second outlet provided on the other axial side of the pump body and is discharged. In this way, the gas purification device described in claim 5 allows the purified gas and the second gas to be discharged without stopping the introduction of the mixed gas, thereby improving the purification efficiency of the purified gas.

[0018] The gas purification device described in claim 6 is a piston-type gas purification device in the configuration described in claim 1 or claim 2, wherein the housing is a cylindrical cylinder, the driver is a piston provided inside the cylinder and that repeatedly increases and decreases the volume of the gas storage section formed between the cylinder and the housing by reciprocating motion between top dead center and bottom dead center, and the adsorption section is provided on at least a portion of the upper surface of the piston.

[0019] The gas purification device described in claim 6 is a piston-type gas purification device, and therefore has a gas reservoir formed between a cylinder serving as a housing and a piston serving as a driver. The volume of the gas reservoir repeatedly increases and decreases due to the reciprocating motion of the piston, thereby achieving a predetermined flow rate of the mixed gas and simultaneously separating the second gas that has come into contact with the adsorption section. This allows purified gas to be obtained from the mixed gas by utilizing the piston driving principle known, for example, as a structure of a vehicle internal combustion engine.

[0020] The gas purification device according to claim 7, in the configuration according to claim 6, further comprises an inlet valve that opens and closes the inlet, a first outlet valve that opens and closes the first outlet, and a second outlet valve that opens and closes the second outlet, wherein the inlet valve opens while the piston moves from top dead center to bottom dead center to introduce the mixed gas into the gas storage portion, and the inlet valve, the first outlet valve, and the second outlet valve close while the piston moves from bottom dead center to top dead center to reduce the volume of the gas storage portion by reducing the intake gas. the second gas is adsorbed into a receiving portion of the gas storage portion; the first outlet valve opens before the piston reaches the top dead center to discharge the purified gas from the gas storage portion; the inlet valve, the first outlet valve, and the second outlet valve close while the piston moves from the top dead center to the bottom dead center to desorb the second gas from the adsorption portion due to an increase in the volume of the gas storage portion; and the second outlet valve opens while the piston moves from the bottom dead center to the top dead center to discharge the second gas from the gas storage portion.

[0021] In a gas purification apparatus according to claim 7, the inlet valve opens while the piston moves from top dead center to bottom dead center, introducing the mixed gas into the gas storage section. The inlet valve, first outlet valve, and second outlet valve then close while the piston moves from bottom dead center to top dead center, causing the second gas to be adsorbed into the adsorption section due to a decrease in the volume of the gas storage section. The first outlet valve then opens before the piston reaches top dead center, allowing the purified gas to be discharged from the gas storage section. The inlet valve, first outlet valve, and second outlet valve then close while the piston moves from top dead center to bottom dead center, causing the second gas to be desorbed from the adsorption section due to an increase in the volume of the gas storage section. The second outlet valve then opens while the piston moves from bottom dead center to top dead center, allowing the second gas to be discharged from the gas storage section. In this way, in the gas purification apparatus of claim 7, a pressurization step of pressurizing the gas storage section and a depressurization step of depressurizing the gas storage section are repeated in conjunction with the reciprocating motion of the piston by opening and closing the inlet valve, first outlet valve, and second outlet valve. This makes it possible to increase the pressure difference between pressurization and depressurization, thereby improving the adsorption and desorption efficiencies of the second gas. As a result, a purified gas with a high concentration of the first gas can be obtained. [Effects of the Invention]

[0022] As described above, the gas purification device according to the present invention has the effect of reducing the size of the housing and suppressing energy consumption during operation. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view schematically illustrating the appearance of a gas purification device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, showing the inside of the housing of the gas purification device according to the first embodiment. [Figure 3] FIG. 2 is a schematic diagram illustrating a cycle in which a second gas is separated from a mixed gas using the gas purification device according to the first embodiment, and purified gas having an increased concentration of the first gas is extracted. [Figure 4] FIG. 2 is a schematic diagram illustrating a cycle in which a second gas is desorbed from an adsorption section and discharged from the gas purification device using the gas purification device according to the first embodiment. [Figure 5] FIG. 3 is a perspective view schematically showing the appearance of a modified example of the gas purification device according to the first embodiment. [Figure 6] 6 is a cross-sectional view taken along line 6-6 in FIG. 5, showing the inside of a housing of a gas purification device according to a modified example. [Figure 7] FIG. 10 is a schematic diagram illustrating a cycle in which a second gas is desorbed from an adsorption section and discharged from the gas purification device using a gas purification device according to a modified example. [Figure 8] FIG. 4 is a vertical cross-sectional view schematically showing the configuration of a gas purification device according to a second embodiment. [Figure 9] FIG. 10 is a schematic diagram illustrating a cycle in which a second gas is separated from a mixed gas using a gas purification device according to the second embodiment, a purified gas having an increased concentration of the first gas is discharged, and then the second gas is desorbed from the adsorption section and discharged from the gas purification device. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, a gas purification device according to the present invention will be described with reference to FIGS. 1 to 9. The gas purification device according to the present invention separates a second gas from a mixed gas containing at least a first gas and a second gas, and delivers a purified gas in which the concentration of the first gas has been increased. The type of mixed gas is not particularly limited, but in each embodiment, a mixed gas containing hydrogen gas and oxygen gas will be described as an example. Hydrogen gas is an example of a first gas, and oxygen gas is an example of a second gas. Note that the first gas and the second gas do not necessarily have to be a single type of gas, and may be composed of multiple types of gas (mixed gas).

[0025] 1 to 9, the direction indicated by arrow R shown as appropriate in each figure indicates the circumferential direction of the housing, which will be described later, and the direction indicated by arrow D indicates the axial direction of the housing. In FIGS. 1 to 7, the direction indicated by arrow A indicates the rotation direction of the driver. In each embodiment, the circumferential direction R of the housing and the circumferential direction of the driver coincide. Furthermore, in each embodiment, the axial direction of the housing and the axial direction of the driver coincide.

[0026] Unless otherwise specified in the specification, each element is not limited to one and may be present in plural. Furthermore, in the drawings, substantially identical elements are denoted by the same reference numerals, and redundant explanations in the specification will be omitted.

[0027] First Embodiment A gas purification device 10 according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view schematically illustrating the exterior of the gas purification device 10. FIG. 2 is a cross-sectional view of the gas purification device 10 taken along line 2-2 in FIG. 1. As shown in FIGS. 1 and 2, the gas purification device 10 follows the structure of a trochoid pump, which is well known as a structure of a vehicle oil pump or the like. The gas purification device 10 includes a box-shaped pump body 12 that forms the outer shell of the device, an outer rotor 30 housed inside the pump body 12, and an inner rotor 40 inscribed in the outer rotor 30. Here, the pump body 12 and the outer rotor 30 correspond to the "housing" in the present invention. The inner rotor 40 corresponds to the "driver" in the present invention.

[0028] (Pump body) An inlet 14 through which the mixed gas is introduced, a first outlet 16 through which the purified gas is discharged, and a second outlet 18 through which the second gas is discharged are provided on a side surface of the pump body 12 in the axial direction D. The inlet 14, the second outlet 18, and the first outlet 16 are arranged in this order along the rotation direction A of the inner rotor 40 (i.e., the circumferential direction R of the outer rotor 30).

[0029] A gas introduction pipe 24 is connected to the inlet 14. The gas introduction pipe 24 is a supply path for the mixed gas. A first outlet 26 is connected to the first outlet 16, through which purified gas purified within the pump body 12 is discharged via the first outlet 16. Furthermore, a second outlet 28 is connected to the second outlet 18, through which a second gas separated from the mixed gas is discharged via the second outlet 18.

[0030] (Outer Rotor) The outer rotor 30 is housed in and rotatably supported within the pump body 12. The outer rotor 30 is an internal gear formed in a cylindrical shape, and has a plurality of external teeth 32 protruding from an inner surface 30A of the outer rotor 30.

[0031] (inner rotor) The inner rotor 40 is a cylindrical external gear and is disposed inside the outer rotor 30. The inner rotor 40 has a plurality of internal teeth 42 protruding from an outer surface 40A of the inner rotor 40. The number of internal teeth 42 is set to be one less than the number of external teeth 32. The inner rotor 40 is connected to a rotary shaft 46 driven by an electric motor (not shown), and rotates together with the rotary shaft 46. The rotary shaft 46 of the inner rotor 40 is disposed eccentrically with respect to the center (not shown) of the outer rotor 30, and two of the multiple internal teeth 42 adjacent in the rotation direction A are configured to circumscribe the external teeth 32 of the outer rotor 30.

[0032] 2, a gas storage portion R1 is formed between the inner rotor 40 and the outer rotor 30, at the point of contact between two of the multiple internal teeth 42 of the inner rotor 40 that are adjacent in the rotation direction A and the inner surface 30A of the outer rotor 30. The side surface of the gas storage portion R1 is composed of the inner surface 30A of the outer rotor 30 and the outer surface 40A of the inner rotor 40.

[0033] As described above, the rotational axis 46 of the inner rotor 40 is eccentric with respect to the center (not shown) of the outer rotor 30. Therefore, the rotational speed of the outer rotor 40 is slower than that of the inner rotor 40, resulting in a phase difference between the rotational motions of the two. As a result, the volume of the gas storage section R1 repeatedly increases and decreases. As the inner rotor 40 rotates, the gas storage section R1 passes through the inlet 14, the second outlet 18, and the first outlet 16 of the pump body 12 in that order. The volume of the gas storage section R1 gradually increases before and after passing through the inlet 14, drawing in the mixed gas from the inlet 14. The volume of the gas storage section R1 then gradually decreases as the gas passes through the second outlet 18 and reaches the first outlet, pressurizing the gas storage section R1. This allows the purified gas to be discharged (exhausted) as it passes through the first outlet 16. Details of this cycle will be described later.

[0034] (Adsorption part) As shown in Fig. 2, an adsorption section 50 capable of adsorbing the second gas is provided on the side surface of the gas storage section R1, i.e., the inner surface 30A of the outer rotor 30 and the outer surface 40A of the inner rotor 40. As an example, the adsorption section 50 is formed of a thin film of adsorbent provided on the side surface of the gas storage section R1. In this embodiment, the adsorption section 50 is provided on the entire circumference of the inner surface 30A of the outer rotor 30 and the entire circumference of the outer surface 40A of the inner rotor 40. Note that it is not essential to provide the adsorption section 50 on the entire circumference of the inner surface 30A and the outer surface 40A; it is sufficient that the adsorption section 50 is provided on at least a portion of the area constituting the side surface of the gas storage section R1.

[0035] The type of adsorbent contained in the adsorption section 50 is not particularly limited as long as it has the ability to adsorb gas. In this embodiment, a thin film of adsorbent capable of adsorbing oxygen as the second gas is provided on the inner surface 30A of the outer rotor 30 and the outer surface 40A of the inner rotor 40.

[0036] As the adsorbent, for example, zeolite with a porous skeletal structure or metal organic frameworks (MOFs) can be used. A thin film can be formed using an adsorbent synthesized from these materials and a binder material with adhesive properties. In adsorbents containing metal organic frameworks, the adsorption strength for a specific substance to be adsorbed can be varied depending on the lattice size of the metal organic framework and the metal species of the metal ions bridged by the organic ligands. This allows the temperature and pressure ranges within which the adsorption is possible to be adjusted.

[0037] In one example of this embodiment, the adsorption unit 50 is configured to be able to adsorb the second gas when the pressure inside the gas storage unit R1 is equal to or higher than a specific pressure, and to desorb the second gas when the pressure is lower than the specific pressure.

[0038] The adsorption unit 50 is not limited to a thin film of adsorbent. For example, it may be made of powdered zeolite or a sheet-like nonwoven fabric supporting a metal-organic framework. If the second gas has paramagnetic properties, the adsorption unit 50 may be made of a magnet. The adsorption unit 50 may also be made of a sheet-like photocatalyst. When purifying hydrogen gas from a mixed gas containing hydrogen and oxygen, as in this embodiment, LaMgxTa1-xO1+3xN2-3x, TiO2, NaTaO3, or the like can be used as the photocatalyst.

[0039] Next, a cycle for separating a second gas from a mixed gas containing at least a first gas and a second gas and delivering a purified gas having an increased concentration of the first gas will be described with reference to Figures 3 and 4. As an example, Figures 3 and 4 show a purified gas G1 having an increased concentration of hydrogen as the first gas, oxygen G2 as the second gas, and a mixed gas G0 containing the purified gas G1 and oxygen G2.

[0040] First, referring to Figure 3, a cycle in which oxygen G2 is separated from mixed gas G0 and purified gas G1 with an increased hydrogen concentration is discharged will be described. In this cycle, the second outlet 18 is closed. Therefore, only the supply of mixed gas G0 through inlet 14 and the discharge of purified gas G1 through first outlet 16 are permitted. Note that in the cycle shown in Figure 3, the introduction of mixed gas G0 through inlet 14 is continued, thereby pressurizing the gas storage section R1. At this time, the pressure in the gas storage section R1 is set to a specific pressure or higher at which the adsorption section 50 can adsorb oxygen G2.

[0041] 3, the volume of the gas storage portion R1 is smallest just before the inlet 14. The volume of the gas storage portion R1 gradually increases as the gas passes through the inlet 14. As a result, the mixed gas G0 is introduced into the gas storage portion R1 through the inlet 14 due to a suction effect from the inlet 14 toward the gas storage portion R1.

[0042] The mixed gas G0 introduced into the gas storage unit R1 comes into contact with the adsorption unit 50 as the gas storage unit R1 travels from the inlet 14 to the first outlet 16. The adsorption unit 50 adsorbs oxygen G2 contained in the mixed gas G0. As a result, the oxygen G2 is separated from the mixed gas G0, and a purified gas G1 with an increased hydrogen concentration is stored in the storage unit R1.

[0043] Thereafter, the volume of the gas storage section R1 gradually decreases as the gas passes through the inlet 14, pressurizing the gas storage section R1. During this process, a discharge action occurs from the gas storage section R1 toward the first outlet 16. This allows the purified gas G1 in the gas storage section R1 to be discharged from the first outlet 16.

[0044] Next, referring to Figure 4, a cycle in which oxygen G2 as a second gas is desorbed from the adsorption section 50 and discharged from the gas purification device 10 will be described. In this cycle, the inlet 14 is closed. Therefore, the introduction of the mixed gas G0 through the inlet 14 is stopped, and only the discharge of oxygen G2 through the first outlet 16 and the second outlet 18 is permitted. Note that it is not essential to open the first outlet 16; the first outlet 16 may be closed and only the second outlet 18 may be opened.

[0045] In the cycle shown in Fig. 4, the introduction of the mixed gas G0 through the inlet 14 is stopped, and therefore the pressure inside the gas storage section R1 is reduced. At this time, the pressure inside the gas storage section R1 is set to be less than the specific pressure at which the adsorption section 50 desorbs oxygen G2. As a result, the oxygen G2 adsorbed in the adsorption section 50 is desorbed. As the volume of the gas storage section R1 increases as the gas passes through the first outlet 16 and reaches the second outlet 18, the oxygen G2 desorbed from the adsorption section 50 is stored in the gas storage section R1. Then, as the oxygen G2 stored in the gas storage section R1 passes through the second outlet 18, it is discharged from the second outlet 18. The discharge of the oxygen G2 may be achieved by a discharge effect caused by a decrease in the volume of the gas storage section R1 as the gas storage section R1 passes through the second outlet 18. Alternatively, oxygen G2 may be drawn out by making the pressure in second outlet pipe 28 negative relative to the pressure in gas reservoir R1. Second outlet 18 is located upstream of first outlet 16 in the direction of rotation A, so that almost no oxygen G2 remains in gas reservoir R1 after passing through second outlet 18. This completes the extraction of oxygen G2.

[0046] (Action and effect) As described above, in the gas purification device 10 according to the first embodiment, the inner rotor 40 rotates inside the outer rotor 30, and the volume of the gas storage section R1 formed between the outer rotor 30 and the inner rotor 40 repeatedly increases and decreases. As a result, the mixed gas G0 introduced through the inlet 14 is swept away inside the gas storage section R1 as the volume increases and decreases, achieving a flow rate that allows the mixed gas G0 to be discharged through the first outlet 16. Furthermore, the adsorption section 50 provided on the side surface of the gas storage section R1 comes into contact with the mixed gas G0 and adsorbs oxygen G2 (second gas) contained in the mixed gas G0. As a result, oxygen G2 is separated from the mixed gas G0 within the gas storage section R1, and a purified gas G1 with an increased concentration of hydrogen (first gas) is stored within the gas storage section R1. The purified gas G1 can then be discharged through the first outlet 16 provided in the pump body 12.

[0047] In this way, in the gas purification device 10, the mixed gas G0 stored in the gas storage section R1 attains a predetermined flow rate by driving the inner rotor 40, and at the same time, the oxygen G2 contained in the mixed gas G0 is separated by the adsorption action of the adsorption section 50. Therefore, compared to a structure in which an adsorption filter is installed in the mixed gas flow path, energy consumption during operation of a drive source such as a motor is reduced. Furthermore, because the mixed gas G0 attains a predetermined flow rate, a sufficient amount of gas can be passed through, which allows the pump body 12 and outer rotor 30, which serve as housings, to be made smaller.

[0048] In this embodiment, the inner rotor 40 is configured to pressurize the gas storage portion R1 when the volume of the gas storage portion R1 decreases, thereby increasing the contact efficiency between the adsorption portion 50 and the mixed gas G0 and improving the adsorption performance of oxygen G2.

[0049] Furthermore, in this embodiment, the gas purification device 10 is a trochoid pump type gas purification device, and therefore purified gas can be obtained from the mixed gas by using, for example, a trochoid pump, which is known as a structure such as a vehicle oil pump.

[0050] Furthermore, in this embodiment, by stopping the introduction of the mixed gas G0 through the inlet 14, the pressure inside the gas reservoir R1 can be reduced and oxygen G2 can be desorbed from the adsorption unit 50. This simplifies the regeneration cycle of the adsorption unit 50.

[0051] (Modification of the first embodiment) Next, a gas purification device 60 according to a modified example of the first embodiment will be described with reference to Figures 5 to 7. The configuration of the gas purification device 60 basically follows the configuration of the gas purification device 10 according to the first embodiment, and therefore can achieve similar effects. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0052] Fig. 5 is a perspective view schematically showing the appearance of the gas purification device 10 of the gas purification device 60. Fig. 6 is a cross-sectional view of the gas purification device 60 taken along line 6-6 in Fig. 5. As shown in Figs. 5 and 6, in this gas purification device 60, an inlet 14, a first outlet 16, and a heating section 62 are arranged in this order along the rotational direction A (i.e., the circumferential direction R of the outer rotor 30) on one side of the axial direction D of the pump body 12. On the other side of the axial direction D of the pump body 12, a second outlet 18 is arranged at a position overlapping with the heating section 62 when viewed in the axial direction D.

[0053] The heating unit 62 has a heating element, such as a nichrome wire, that generates heat when electricity is applied, and is configured to heat one side of the gas storage unit R1 in the axial direction D to a specific temperature or higher. This generates an airflow in the gas storage unit R1 that flows from one side of the axial direction D to the other side.

[0054] In this embodiment, the adsorption unit 50 is configured to adsorb oxygen G2 as the second gas below a specific temperature and desorb the oxygen G2 at a specific temperature or higher. Therefore, as shown in Fig. 7, when the gas storage unit R1 is heated by heat H from the heating unit 62, the temperature inside the gas storage unit R1 rises to a specific temperature or higher, and the oxygen G2 is desorbed from the adsorption unit 50.

[0055] (Action and effect) In the gas purification device 60, the gas storage section R1 passes through the inlet 14, the first outlet 16, and the heating section 62 in this order as the inner rotor 40 rotates. The gas storage section R1 adsorbs oxygen G2 (second gas) from the mixed gas G0 while moving from the inlet 14 to the first outlet 16, generating a purified gas G1. The gas storage section R1 then discharges the purified gas G1 as it passes through the first outlet 16, and passes through the heating section 62 with the oxygen G2 adsorbed by the adsorption section 50. Within the gas storage section R1 that has passed through the heating section 62, an airflow is generated that flows from one side of the axial direction D of the pump body 12 to the other, and the oxygen G2 desorbed from the adsorption section 50 on this airflow flows toward the second outlet 18 provided on the other side of the axial direction D of the pump body 12 and is discharged.

[0056] In this way, in the gas purification device 60, the purified gas G1 and oxygen G2 can be separated and discharged without stopping the introduction of the mixed gas G0, thereby improving the efficiency of billing the purified gas G1.

[0057] Second Embodiment A gas purification device 70 according to a second embodiment will be described with reference to Figures 8 and 9. Figure 8 is a vertical cross-sectional view showing a schematic configuration of the gas purification device 70. Note that the same components as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0058] As shown in Figures 8 and 9, the gas purification device 70 follows the well-known piston drive principle as a structure of a vehicle internal combustion engine, etc. The gas purification device 70 includes a cylinder block 72 forming the outer shell of the device, a cylinder 80 housed inside the cylinder block 72, and a piston 90 sliding inside the cylinder 80. Here, the cylinder 80 corresponds to the "housing" in this invention. The piston 90 corresponds to the "driver" in this invention.

[0059] (cylinder block) The cylinder block 72 is a support body formed by, for example, casting, and a cylinder 80 and a drive chamber 100 (described later) are housed in an accommodation space formed in the lower part of the cylinder block 72. In addition, a valve support portion 74 serving as an accommodation space for supporting a plurality of valves (described later), and a gas flow path 76 disposed adjacent to the valve support portion 74 are formed in the upper part of the cylinder block 72.

[0060] In this embodiment, three valve support portions 74 are formed. The three valve support portions 74 house an inlet valve 200, a first outlet valve 201, and a second outlet valve 202. Specifically, each valve support portion 74 houses a plate-shaped base end portion 200A that constitutes the base end side of each valve, and a spring 300 inserted into each valve. The spring 300 is inserted between the bottom surface of the valve support portion 74 and the base end portion 200A.

[0061] An inlet flow path 76 is formed in the cylinder block 72 adjacent to a valve support part 74 that supports an inlet valve 200. The inlet flow path 76 is a supply path for mixed gas, and is connected to an inlet 82 provided in a cylinder 80, which will be described later. The tip side of the inlet valve 200 is inserted into the inlet flow path 76 from the bottom surface of the valve support part 74, and a cylinder head 200B provided at the tip closes the inlet 82 from inside the cylinder 80.

[0062] Furthermore, a first outlet flow path 77 is formed in the cylinder block 72 adjacent to the valve support part 74 that supports the first outlet valve 201. The first outlet flow path 77 is an outlet passage for discharging purified gas refined inside the cylinder 80 to the outside, and is connected to a first outlet 84 provided in the cylinder 80, which will be described later. The tip side of the first outlet valve 201 is inserted into the first outlet flow path 76 from the bottom surface of the valve support part 74, and a cylinder head 200B provided at the tip closes the first outlet 84 from inside the cylinder 80.

[0063] Furthermore, a second outlet flow path 78 is formed in the cylinder block 72 adjacent to the valve support part 74 that supports the second outlet valve 202. The second outlet flow path 78 is an outlet passage for discharging the second gas desorbed from the adsorption part 50 inside the cylinder 80 to the outside, and is connected to a second outlet 86 provided in the cylinder 80, which will be described later. The tip side of the second outlet valve 202 is inserted into the second outlet flow path 77 from the bottom surface of the valve support part 74, and a cylinder head 200B provided at the tip closes the second outlet 86 from inside the cylinder 80.

[0064] A camshaft 400 contacts base ends 200A of the inlet valve 200, first outlet valve 201, and second outlet valve 202. The camshaft 400 is connected to a rotary shaft 402 driven by an electric motor or the like (not shown), and rotates together with the rotary shaft 402. The camshaft 402 has a generally egg-shaped ellipse when viewed axially of the rotary shaft 402, and is provided with protrusions that protrude radially around the axis of the rotary shaft 402. As the protrusions of the camshaft 400 rotate, the base ends 200A of the inlet valve 200, first outlet valve 201, and second outlet valve 202 are periodically pressed toward the cylinder block 72. The pressing force causes the cylinder head 200B to slide while elastically deforming the spring 300, thereby opening the corresponding openings of the cylinder 80. Furthermore, as the protrusion of camshaft 400 further rotates and the pressure on base end 200A is released, the elastic return of spring 300 pushes inlet valve 200, first outlet valve 201, and second outlet valve 202 out of cylinder 80. This causes cylinder head 200B to slide, closing the corresponding openings of cylinder 80 again.

[0065] By repeating the above cycle, the inlet 82 of the cylinder 80 can be opened and closed by the inlet valve 200. The first outlet 84 of the cylinder 80 can be opened and closed by the first outlet valve 201. The second outlet 86 of the cylinder 80 can be opened and closed by the second outlet valve 202.

[0066] (cylinder) The cylinder 80 is formed in a cylindrical shape extending along the axial direction D, and an inlet 82, a first outlet 84, and a second outlet 86 are arranged on a ceiling surface provided at one end in the axial direction D. The mixed gas is introduced into the inlet 82 via the introduction flow path 76. The first outlet 84 is an outlet through which the purified gas purified in the gas storage section R2 inside the cylinder 80 is discharged to the outside. The second outlet 86 is an outlet through which the second gas desorbed from the adsorption section 50 is discharged to the outside.

[0067] The other end of the cylinder 80 in the axial direction D is connected to a box-shaped drive chamber 100. The drive chamber 100 accommodates an electric motor (not shown) as a drive source for driving a piston 90 (described later), a rotary shaft 102 connected to the main shaft of the electric motor, and a disk-shaped rotor 104 connected to the rotary shaft 102. The rotor 104 transmits driving force to the piston head 94 via a rod-shaped piston arm 94.

[0068] (piston) The piston 90 is provided inside the cylinder 80, and forms a gas storage section R2 between the piston 90 and the cylinder 80. Specifically, the piston 80 includes a piston head 92 disposed on one side in the axial direction D, and a piston arm 94 that connects the piston head 92 to the rotor 104. The piston head 92 divides the internal space of the cylinder 80 into one side and the other in the axial direction D, and the space on one side in the axial direction D is the gas storage section R2. In other words, the side of the gas storage section R2 is formed by the inner side surface 80A of the cylinder 80 and the upper surface 92A of the piston head 92 (the upper surface of the piston).

[0069] The piston arm 94 extends with the axial direction D as its longitudinal direction. One longitudinal end of the piston arm 94 is rotatably connected to the piston head 92 via a first connecting portion 94A. The other longitudinal end of the piston arm 94 is rotatably connected to the rotor 104 via a second connecting portion 94B. This base 2 connecting portion 94B is provided at a position eccentric to the center of the rotor 104, thereby converting the rotational motion of the rotor 104 into linear reciprocating motion and transmitting it to the piston head 92. This allows the piston head 92 to reciprocate between top dead center P1 and bottom dead center P2. The reciprocating motion of the piston head 92 causes the gas reservoir R2 to repeatedly increase and decrease in volume.

[0070] Here, the adsorption section 50 is provided on the entire upper surface 92A of the piston head 92. Therefore, the volume of the gas storage section R2 repeatedly increases and decreases due to the reciprocating motion of the piston 90, and the mixed gas introduced into the cylinder 80 gains a flow velocity and comes into contact with the adsorption section 50. The configuration of the adsorption section 50 is the same as in the first embodiment, so a detailed description will be omitted. Note that it is not essential to provide the adsorption section 50 on the entire upper surface 92A of the piston head 92; it is sufficient that the adsorption section 50 is provided on at least a portion of the upper surface 92A.

[0071] Next, a cycle in which a second gas is separated from a mixed gas, a purified gas having an increased concentration of a first gas is discharged, and then the second gas is desorbed from the adsorption section and discharged from the gas purification device will be described with reference to Fig. 9. Fig. 9 shows, as an example, a purified gas G1 having an increased concentration of hydrogen as the first gas, oxygen G2 as the second gas, and a mixed gas G0 containing the purified gas G1 and oxygen G2.

[0072] As shown in FIG. 9, the inlet valve 200 opens while the piston 90 moves from the top dead center P1 to the bottom dead center P2, and introduces the mixed gas G0 into the gas storage portion R2.

[0073] Thereafter, the inlet valve 200, the first outlet valve 201, and the second outlet valve 202 close while the piston 90 moves from the bottom dead center P2 to the top dead center P1, and the volume of the gas storage portion R2 decreases, causing oxygen G2 (second gas) to be adsorbed into the adsorption portion 50. During this time, the inside of the gas storage portion R2 is pressurized.

[0074] Next, the first outlet valve 201 opens before the piston 90 reaches the top dead center (TDC) 1, and the purified gas G1 is discharged from the gas reservoir R2.

[0075] The inlet valve 200, the first outlet valve 201, and the second outlet valve 202 close while the piston 90 moves from the top dead center P1 to the bottom dead center P2, and the volume of the gas storage section R2 increases, causing oxygen G2 to be desorbed from the adsorption section 50. During this time, the pressure inside the gas storage section R2 is reduced.

[0076] The second outlet valve 202 opens while the piston 90 moves from the bottom dead center P2 to the top dead center P1, and allows oxygen G2 to be discharged from the gas reservoir R2.

[0077] (Action and effect) As described above, in the gas purification device 70 according to the second embodiment, a gas reservoir R2 is formed between the cylinder 80 and the piston 90. The reciprocating motion of the piston 90 repeatedly increases and decreases the volume of the gas reservoir R2, causing the mixed gas G0 to flow at a predetermined rate and contact the adsorption unit 50. The adsorption unit 50 separates oxygen G2 (second gas) from the mixed gas G0, and stores purified gas G1 with an increased concentration of hydrogen (first gas) in the gas reservoir R2. This reduces energy consumption during operation of a drive source such as a motor, as with the gas purification device 10 according to the first embodiment, compared to a structure in which an adsorption filter is installed in the mixed gas flow path. Furthermore, since the mixed gas G0 flows at a predetermined rate, a sufficient amount of gas can be passed through the cylinder 80, which serves as a housing, allowing for a more compact design.

[0078] Furthermore, since the gas purification device 70 is a piston-type gas purification device, it is possible to obtain purified gas from the mixed gas by utilizing the well-known piston driving principle as the structure of, for example, a vehicle internal combustion engine.

[0079] In this embodiment, a pressurization step of pressurizing the gas storage section R2 and a depressurization step of depressurizing the gas storage section R2 are repeated in conjunction with the reciprocating motion of the piston 90 by opening and closing the inlet valve 200, the first outlet valve 201, and the second outlet valve 202. This increases the pressure difference between pressurization and depressurization, improving the adsorption and desorption efficiencies of oxygen G2. As a result, a purified gas G1 with a high hydrogen concentration can be obtained.

[0080] Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to these and can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0081] 10 Gas purification equipment 12 Pump body (housing) 14 Introduction 16 1st outlet 18 2nd outlet 30 Outer rotor (housing) 30A inner side 32 outer teeth 40 Inner rotor (driver) 40A outer surface 42 Inner teeth 46 Rotation axis 50 Adsorption part R1 Gas storage section G0 mixed gas G1 Purified Gas G2 Oxygen (second gas) 60 Gas Purification Equipment 62 Heating section 70 Gas Purification Equipment 80 Cylinder (housing) 82 entrance 84 1st outlet 86 2nd outlet 90 Piston (driver) 92A Top of cylinder head (top of piston) 200 Inlet valve 201 First outlet valve 202 Second outlet valve P1 Top dead center P2 Bottom dead center R2 gas reservoir

Claims

1. A gas purification device that separates a second gas from a mixed gas containing at least a first gas and a second gas, and delivers a purified gas in which a concentration of the first gas is increased, a housing having an inlet through which the mixed gas is introduced, a first outlet through which the purified gas is discharged, and a second outlet through which the second gas is discharged; a driver provided inside the housing, forming a gas storage section between the housing and the driver, and repeatedly increasing and decreasing the volume of the gas storage section when driven; an adsorption section provided on at least a part of a side surface of the gas storage section, the adsorption section being capable of adsorbing the second gas by contact with the mixed gas; A gas purification device comprising:

2. The driver is configured to pressurize the gas storage portion when the volume of the gas storage portion decreases. The gas purification system according to claim 1 .

3. A trochoid pump type gas purification device, The housing includes a cylindrical pump body and an outer rotor that is accommodated in the pump body and rotatably supported, and that has a plurality of external teeth protruding from an inner surface thereof, the driver is an inner rotor that protrudes from an outer surface of the driver and has a plurality of internal teeth circumscribing the external teeth, the inner rotor has a rotation axis that is eccentric with respect to the outer rotor, and is configured so that the volume of the gas storage portion formed between the external teeth and the internal teeth repeatedly increases and decreases by rotation around the rotation axis; The suction portion is provided on all or part of at least one of the inner surface of the housing and the outer surface of the driver. The gas purification apparatus according to claim 1 or 2.

4. an interior of the gas storage section is pressurized by introducing the mixed gas through the inlet, and is depressurized by stopping the introduction of the mixed gas through the inlet; The adsorption unit is configured to desorb the second gas by reducing the pressure inside the gas storage unit. The gas purification system according to claim 3.

5. a heating unit provided on one axial side of the pump body, the heating unit heating the one axial side of the gas storage unit to a specific temperature or higher and generating an airflow in the gas storage unit from one axial direction to the other, the inlet, the first outlet, and the heating portion are arranged in this order on one axial side of the pump body along the circumferential direction of the outer rotor, the second outlet is disposed on the other axial end of the pump body at a position overlapping with the heating portion as viewed in the axial direction, the adsorption unit is configured to adsorb the second gas at a temperature lower than a specific temperature and to desorb the second gas at a temperature equal to or higher than the specific temperature, and the second gas is desorbed when the gas storage unit passes through the heating unit. The gas purification system according to claim 3.

6. A piston-type gas purification device, the housing is a cylindrical cylinder, the driver is a piston that is provided inside the cylinder and that repeatedly increases and decreases the volume of the gas storage section formed between the driver and the cylinder by reciprocating between a top dead center and a bottom dead center, The adsorption portion is provided on at least a part of the upper surface of the piston. The gas purification apparatus according to claim 1 or 2.

7. an inlet valve that opens and closes the inlet; a first outlet valve that opens and closes the first outlet; a second outlet valve that opens and closes the second outlet, the inlet valve opens while the piston moves from top dead center to bottom dead center to introduce the mixed gas into the gas storage portion; the inlet valve, the first outlet valve, and the second outlet valve are closed while the piston moves from the bottom dead center to the top dead center, and the volume of the gas storage portion is reduced to allow the second gas to be adsorbed by the adsorption portion; the first outlet valve opens before the piston reaches the top dead center to allow the purified gas to be discharged from the gas storage section; the inlet valve, the first outlet valve, and the second outlet valve are closed while the piston moves from the top dead center to the bottom dead center, and the second gas is desorbed from the adsorption unit by an increase in the volume of the gas storage unit; The second outlet valve is configured to open while the piston moves from the bottom dead center to the top dead center, and to discharge the second gas from the gas storage portion. The gas purification apparatus according to claim 6.

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