TRANSFER DEVICE

Abstract

A transfer device includes at least one pump unit provided for a defined gas transfer between a first, closed-off space of an installation, in particular a photobioreactor installation, and a second space which is separate from the first space. The at least one pump unit is embodied as a selective oxygen pump.

Claims

1. A transfer device with at least one pump unit provided for a defined gas transfer between a first, closed-off space of an installation, in particular a photobioreactor installation, and a second space which is separate from the first space, wherein the at least one pump unit is embodied as a selective oxygen pump.

2. The transfer device according to claim 1, wherein the at least one pump unit comprises at least one zirconium oxide element, which is provided for a selective transfer of oxygen out of the first space into the second space.

3. The transfer device according to claim 2, wherein the at least one pump unit comprises at least one heating element, which is provided for heating the at least one zirconium oxide element.

4. The transfer device according to claim 2, wherein the at least one zirconium oxide element of the at least one pump unit is implemented by a doped zirconium oxide element.

5. The transfer device according to claim 2, wherein the at least one zirconium oxide element of the at least one pump unit is provided, depending on a polarity of a pump flow, for a bi-directional oxygen transfer between the first space and the second space.

6. The transfer device according to claim 1, wherein the at least one pump unit is provided for specifically and selectively separating off oxygen.

7. The transfer device according to claim 1, wherein the at least one pump unit is in at least one operating state provided for an electrical reduction of at least one gas.

8. The transfer device according to claim 1, wherein the at least one pump unit is provided for an accumulation of a reduced gas in the first space and/or the second space.

9. The transfer device according to claim 1, further comprising at least one measuring unit, which is provided for capturing a voltage difference between at least two sides of the pump unit.

10. The transfer device according to claim 9, wherein the at least one measuring unit is provided for deducting a pressure difference between the first space and the second space on the basis of the voltage difference.

11. An installation with a transfer device according to claim 1.

12. The installation according to claim 11, further comprising a control and/or regulation unit, which is provided for controlling and/or regulating an absolute oxygen partial fraction in the first space outside a reaction area via the transfer device.

13. The installation according to claim 11, further comprising at least one photobioreactor unit, which is provided for receiving fed-in carbon dioxide, generating oxygen via photosynthesis and outputting oxygen.

14. A method for operating an installation according to claim 11.

15. The method according to claim 14, wherein an absolute oxygen partial fraction in the first space outside a reaction area is controlled and/or regulated via the transfer device.

16. The method according to claim 14, wherein the transfer device is used for monitoring and/or for adjusting at least one safety-relevant operating state.

17. The method according to one of claims 14, wherein the performance is effected under conditions of reduced or increased gravity.

18. The method according to one of claims 14, further comprising performance in an ISRU application.

19. The method according to one of claims 14, further comprising performance in an Environmental Control System.

Description

DRAWINGS

[0024] Further advantages will become apparent from the following description of the drawings. The drawings show an exemplary embodiment of the invention. The drawings, the description and the claims contain a plurality of features in combination. Someone skilled in the art will purposefully also consider the features individually and will find further expedient combinations.

[0025] It is shown in:

[0026] FIG. 1 an installation featuring a photobioreactor unit, a control and regulation unit and a transfer device in a schematic presentation,

[0027] FIG. 2 the transfer device featuring a pump unit, which comprises a zirconium oxide element in a schematic presentation,

[0028] FIG. 3 a partial section III-III of FIG. 2 of the transfer device in a schematic presentation, and

[0029] FIG. 4 a diagram showing gas concentrations over time during exemplary operation of the installation with an algae reactor.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

[0030] FIG. 1 shows an installation 16. The installation 16 is implemented by a photobioreactor installation. The installation 16 is provided for use in outer space. The installation 16 comprises a space 14. The space 14 is implemented by a closed-off space. Furthermore the installation 16 comprises a photobioreactor unit 36. Principally the installation 16 may also comprise a plurality of photobioreactor units 36. The installation 16 may principally also comprise other reactors which are deemed expedient by someone skilled in the art. The photobioreactor unit 36 is arranged in the space 14. The photobioreactor unit 36 is provided for receiving fed-in carbon dioxide CO.sub.2 and for generating and outputting oxygen O.sub.2 via photosynthesis, using a light source 44. The installation 16 comprises a gas tank 38. The gas tank 38 is implemented by a carbon dioxide tank. The gas tank 38 is connected to the space 14 by means of a valve via a line. The valve 40 is exemplarily implemented by a magnet valve. For a reaction of the photobioreactor unit 36, carbon dioxide CO.sub.2 is conveyed into the space 14 from the gas tank 38. A quantity of carbon dioxide CO.sub.2 is herein controlled via the valve 40.

[0031] The photobioreactor unit 36 is provided for production and/or cultivation of microorganisms, e.g. algae, cyanobacteria, moss plants, and/or phyto-cell cultures within an artificial technical environment. The photobioreactor unit 36 comprises an algae culture as an example of a photosynthetic system. The photobioreactor unit 36 is provided for using the photosynthesis process of produced and/or cultivated microorganisms for generating oxygen O.sub.2 from light, carbon dioxide CO.sub.2 and water via photosynthesis. The photobioreactor unit 36 comprises a receiving element 42 for receiving the microorganisms. The receiving element 42 may be implemented, for example, by a pipeline, a plate and/or another receiving element 42 deemed expedient by someone having ordinary skill in the art. The photobioreactor unit 36 further comprises a light source 44. The light source 44 is implemented by an artificial light source. Principally, however, it would also be conceivable that sunlight is used as a light source. The light source 44 is provided for an irradiation of the microorganisms during operation. The photobioreactor unit 36 forms a reaction area 34 of the installation 16.

[0032] The installation further comprises a transfer device 10. The transfer device 10 is implemented by a photobioreactor transfer device. The transfer device 10 is arranged between the first space 14 of the installation 16 and a second space 18. The second space 18 forms an environment of the installation 16. The second space 18 is embodied separate from the first space 14 of the installation 16. The second space 18 is in the present embodiment embodied by the cabin of a space station. The transfer device 10 borders both on the first space 14 and the second space 18. An operating pressure of the first space 14 may be between 10.sup.−3 mbar and 100 bar. An operating pressure of the second space 18 may be between the pressure of the first space 14 and 100 bar. Preferably an operation of the transfer device 10 is performed at ambient pressure, preferentially in a range of 750 mbar to 1250 mbar in the first space 14 and in a range of 800 mbar to 1500 mbar in the second space 18.

[0033] Furthermore the transfer device 10 comprises a pump unit 12. The pump unit 12 is provided for a defined gas transfer between the first, closed-off space 14 of the installation 16 and the second space 18, which is separate from the first space 14. The pump unit 12 is embodied as a selective oxygen pump. The pump unit 12 is implemented by an electro-chemical oxygen pump. The pump unit 12 further comprises a zirconium oxide element 20. The zirconium oxide element 20 is provided for a selective transfer of oxygen O.sub.2 from the first space 14 into the second space 18. The zirconium oxide element 20 is embodied by a zirconium oxide ceramic. The zirconium oxide element 20 is implemented by a doped zirconium oxide element. The zirconium oxide element 20 is doped with yttrium oxide (Y.sub.2O.sub.3). Principally, it would however be also conceivable for the zirconium oxide element 20 to be embodied by a non-doped zirconium oxide element. For this purpose, the zirconium oxide element 20 is embodied by a zirconium oxide tube which is closed on one side. The zirconium oxide element 20 is embodied “test-tube-shaped”. Principally, however, another shaping deemed expedient by someone skilled in the art is also conceivable. For example, a planar design of the zirconium oxide element 20 is also conceivable, the plane forming a separating plane between the two spaces 14, 18. The zirconium oxide element 20 hence forms a hollow space 46. The zirconium oxide element 20 protrudes into the second space 18 with a closed side. An open side of the zirconium oxide element 20 protrudes into the first space 14. Principally, however, it would also be conceivable that the zirconium oxide element 20 protrudes into the first space 14 with a closed side, an open side of the zirconium oxide element 20 protruding into the second space 18. The hollow space 46 of the zirconium oxide element 20 is connected to the first space 14. The pump unit 12 further comprises a guiding tube 48 protruding from the first space 14 into the hollow space 46. The guiding tube 48 serves for guiding gas flowing into the hollow space 46. The guiding tube 48 extends in parallel to the zirconium oxide element 20. The guiding tube 48 is paced apart from the zirconium oxide element 20. The guiding tube 48 extends up to shortly before a closed side of the zirconium oxide element 20. Via the guiding tube 48 gas can flow into the hollow space 46. Gas situated in the hollow space 46 is provided to flow in a gap of the hollow space 46, between the guiding tube 48 and the zirconium oxide element 20, out of the hollow space 46. As a result of this, advantageous circulation is achievable. Moreover, it is achievable that the hollow space 46 is flown through in an advantageously uniform fashion (FIG. 2).

[0034] Beyond this the pump unit 12 comprises two electrodes 50, 52. The electrodes 50, 52 are at least partly made of platinum. The electrodes 50, 52 are respectively implemented by a structured electrode having free spaces between the electrode material. The electrodes 50, 52 serve additionally as a catalyzer for a dissociation of oxygen-containing gases, e.g. SO.sub.2, CO.sub.2, NO, NO.sub.2 or O.sub.3, and/or for selectively separating off oxygen O.sub.2. Principally, however, a different implementation of the electrodes which is deemed expedient by someone skilled in the art would be also conceivable. In particular, other electrode materials are conceivable, e.g. palladium, rhodium, cobalt, iridium and/or nickel. Principally, using a separate catalyzer, apart from the electrodes 50, 52 would also be conceivable. A first electrode 50 of the pump unit 12 is arranged on an inner side of the zirconium oxide element 20, which faces towards the hollow space 46. The first electrode 50 extends over a major part of an inner side of the zirconium oxide element 20. The first electrode 50 is arranged between the zirconium oxide element 20 and the first space 14. A second electrode 52 of the pump unit 12 is arranged on an outer side of the zirconium oxide element 20, which faces away from the hollow space 46. The second electrode 52 of the pump unit 12 is arranged on an outer side of the zirconium oxide element 20, on an end of the zirconium oxide element 20 which faces away from the open end of the zirconium oxide element 20. On a side of the zirconium oxide element 20 facing away from the open end of the zirconium oxide element 20, the zirconium oxide element 20 is encompassed by the second electrode 52 to a major part. The second electrode 52 is arranged between the zirconium oxide element 20 and the second space 18. The electrodes 50, 52 are connected to a power source 54 via lines. The power source 54 embodies a shared voltage source of the electrodes 50, 52. The power source 54 provides a pump flow. The zirconium oxide element 20 of the pump unit 12 is provided for bi-directional oxygen transfer between the first space 14 and the second space 18 (FIG. 2), depending on a polarity 24 of the pump flow.

[0035] The pump unit 12 also comprises a heating element 22. The heating element 22 is provided for heating the zirconium oxide element 20. The heating element 22 is provided for heating the zirconium oxide element 20 to an operating temperature and to keep it at said operating temperature. The heating element 22 is provided for heating the zirconium oxide element 20 to an operating temperature between 500° C. and 700° C. and to keep it at said operating temperature. The heating element 22 is implemented by an infrared radiant heater. Principally, however, a different implementation of the heating element 22 deemed expedient by someone skilled in the art would also be conceivable, in particular as a resistance heater. The heating element 22 is embodied tube-shaped. Principally, however, a different implementation deemed expedient by someone skilled in the art would also be conceivable. For example, in case of the zirconium oxide element 20 being embodied flat, in particular plate-shaped, the heating element 22 could principally also consist of two partial heating elements, which are respectively arranged on opposite sides of the zirconium oxide element 20. The heating element 22 encompasses the zirconium oxide element 20 on its outer surface in a region of the second electrode 52. The heating element 22 extends in parallel to a main extension direction of the zirconium oxide element 20. The heating element 22 is spaced apart from the zirconium oxide element 20 as well as from the second electrode 52 (FIG. 2).

[0036] The zirconium oxide element 20 acts as a selective oxygen pump, transporting oxygen O.sub.2 only if the zirconium oxide element 20 is at operating temperature and a pump flow is flowing between an inner side and an outer side of the zirconium oxide element 20. The pump unit 12 is herein provided for an electrical reduction of at least one gas. Under these operative conditions the zirconium oxide element 20 acts as an ion conductor and/or as a solid-matter electrolyte. The mode of operation of the pump unit 12 is that oxygen O.sub.2 is selectively pumped out of a gas mixture in the first space 14 into the second space 18. The pump unit 12 is herein provided for specifically and selectively separating off oxygen O.sub.2. Principally, however, the pump unit 12 may thus also be used for specifically accumulating a reduced gas in the first space 14 or the second space 18 (FIGS. 2 and 3).

[0037] The transfer device 10 further comprises a measuring unit 26. The measuring unit 26 is provided for capturing a voltage difference between two sides 28, 30 of the pump unit 12. The measuring unit 26 is provided for capturing a voltage difference between a first side 28, which faces towards the first space 14, and a second side 30 of the pump unit 12, which faces toward the second space 18.For this purpose the measuring unit 26 comprises a voltmeter. The measuring unit 26 is connected to the first electrode 50 of the pump unit 12 via a line. The measuring unit 26 is furthermore connected to a third electrode 56 via a line. The third electrode 56 is arranged on an outer side of the zirconium oxide element 20 that faces away from the hollow space 46. Principally, however, it would also be conceivable for the third electrode 56 to be arranged in another way that is deemed expedient by someone skilled in the art. The third electrode 56 is arranged on an outer side of the zirconium oxide element 20 between the open end of the zirconium oxide element 20 and the second electrode 52. The third electrode 56 is separate with respect to the second electrode 52 and has no electrical connection to the second electrode 52. The third electrode 56 is embodied annulus-shaped and extends around the zirconium oxide element 20. The third electrode 56 is arranged between the zirconium oxide element 20 and the second space 18. The measuring unit 26 is provided for capturing a voltage difference between the first electrode 50 and the third electrode 56. The measuring unit 26 is provided for deducting a pressure difference between the first space 14 and the second space 18 on the basis of the voltage difference. The measuring unit 26 is provided for deducting a partial pressure difference between the first space 14a and the second space 18 on the basis of the voltage difference. Beyond this a present oxygen concentration and/or differences in the oxygen concentrations of the spaces 14, 18 may be determined, in particular if an oxygen partial pressure in the first space 14 and/or in the second space are/is known (FIG. 2).

[0038] The installation 16 further comprises a control and regulation unit 32. The control and regulation unit 32 comprises a control electronics component. The control and regulation unit 32 is provided for regulating an absolute oxygen partial fraction in the first space 14 outside the reaction area 34 via the transfer device 10. The control and regulation unit 32 is provided for regulating an absolute oxygen partial fraction in the first space 14 outside a reaction area 34 to a value of approximately 15%. The control and regulation unit 32 is provided for monitoring the absolute oxygen partial fraction. The control and regulation unit 32 uses the measuring unit 26 of the transfer device 10 for monitoring the absolute oxygen partial fraction. Principally, however, it would also be conceivable that the control and regulation unit 32 comprises a separate sensor for monitoring the absolute oxygen partial fraction. The control and regulation unit 32 is provided for regulation an absolute oxygen partial fraction in the first space 14 outside a reaction area 34 by pumping off oxygen O.sub.2 via the transfer device 10. For this purpose, the control and regulation unit 32 is provided to control the power source 54 of the pump unit 12. The pump rate of the transfer device 10 is influenced by the applied current rating. The pump rate of the transfer device is further influenced by a geometry, in particular a surface, of the zirconium oxide element 20. With a selected geometry, the current rating of the power source 54 is varied during operation to adjust the required oxygen transfer rate from the first space 14 into the second space 18 and to regulate the oxygen partial pressure in the first space 14 to a predetermined value. Principally the pump performance may also be adjusted via further electrical operation parameters, e.g. the operation temperature. The pump rate of the transfer device 10 can be varied in a range between a few milliliters per day and several liters per day, depending on dimensions of the zirconium oxide element 20 and on a strength of the pump flow.

[0039] FIG. 4 shows an exemplary diagram of a measuring record of a gas concentration in the first space 14, in particular without a regulation as described above. The diagram shows an oxygen concentration 62 and a carbon dioxide concentration 66 in the space 14 over time tin %. Herein the diagram shows a variation of an oxygen output rate 58, 58′ (dO.sub.2/dt), respectively shown by tangents at points in time t.sub.1 and t.sub.2, out of the photobioreactor unit 36 depending on a constant carbon dioxide reception rate 60, 60′ (dCO.sub.2/dt), respectively shown by tangents at points in time t.sub.1 and t.sub.2, in the first space 14. In case of a constant carbon dioxide reception rate 60, the oxygen output rate 58 (dO.sub.2/dt) decreases with increasing oxygen concentration 62 in the first space 14. Following a first exemplary rinsing process 64 of the first space 14 with nitrogen N.sub.2 and addition of carbon dioxide CO.sub.2, the molar oxygen output rate 58 is equal to the molar carbon dioxide reception rate 60 (dCO.sub.2/dt). This behavior could be observed until an oxygen concentration 62 of approximately 15% in the first space 14. Above this the oxygen output rate 58 (dO.sub.2/dt) decreases significantly. Hence a ratio of dCO.sub.2/dt=−dO.sub.2/dt is achievable, which is equimolar as regards its absolute value, if the oxygen concentration 62 in the first space 14 outside the reaction area 14 is actively kept at a reduced value of approximately up to 15%. This results in a control variable of the oxygen concentration 62 of approximately 15%.

[0040] In a method for operating the installation 16 an absolute oxygen partial fraction in the first space 14 outside a reaction area 34 is regulated via the transfer device 10. The absolute oxygen partial fraction in the first space 14 outside a reaction area 34 is regulated via the transfer device 10 to a value of approximately 15%. For this purpose the control and regulation unit 32 controls the transfer device 10. For this purpose the control and regulation unit 32 controls the power source 54 of the pump unit 12 of the transfer device 10. Due to the voltage applied to the first electrode 50 and the second electrode 52, oxygen O.sub.2 of the first space 14 is reduced to anions O.sup.2− by taking in electrons at the first electrode 50, which acts as a cathode. This reaction is supported by the platinum of the electrode 50 serving as a catalyzer. The anions O.sup.2− then migrate through the zirconium oxide element 20, which herein acts as an ion conductor and/or solid-matter electrolyte, to the second electrode 52. At the second electrode 52 the anions O.sup.2− react in the second space 18 back to oxygen O.sub.2 by releasing the electrons (FIG. 3).

[0041] The method may principally also be performed in an ISRU application. The method is herein applicable for separating off and/or accumulating oxygen from a local gas mixture and/or from local solid bodies on the basis of In-Situ-Resource-Utilization (ISRU) applications on planets. Principally, the installation 16 may for this purpose also comprise alternative reactors. In particular, the installation 16 may comprise alternative reactors for physicochemical, biochemical and/or biological processes, which in particular release oxygen.

[0042] Furthermore, the method may principally also be performed in an Environmental Control System. The method may herein be used for pressure and temperature regulation as well as for oxygen supply in an at least substantially closed system, e.g. in particular a spacecraft, aircraft, landcraft or watercraft. Principally the installation 16 may for this purpose also comprise alternative reactors. In particular, the installation 16 may comprise alternative reactors for physicochemical, biochemical and/or biological processes.

[0043] The transfer device 10 is further used for monitoring and adjusting safety-relevant operating states. By means of the measuring unit 26 of the transfer device 10 a voltage difference between two sides 28, 30 of the pump unit 12 is captured. The measuring unit 26 captures, during operation of the installation 16, a voltage difference between a first side 28, which faces the first space 14, and a second side 30 of the pump unit 12, which faces the second space 18. Moreover the measuring unit 26 deducts, during operation of the installation 16, a partial pressure difference between the first space 14 and the second space 18 on the basis of the voltage difference (FIG. 3).

[0044] Performance of the method is effected under conditions of reduced or increased gravity. The method is performed in outer space, at local gravity values of 10.sup.−6 xg up to 10 xg. The method is applied in particular in outer space, e.g. at μg in a spaceship, in a process in a spaceship under accelerations of 10.sup.−6 xg up to 10 xg, on a planet, e.g. Mars, and/or on a natural satellite, e.g. the moon. However, the installation 16 and/or a reactor of the installation 16 may also be exposed to an artificial process acceleration which differs from the gravity values given. The gravity values may thus be increased drastically, e.g. for technical reasons, for example to 100 xg.