Abstract
The present invention relates to a gassing unit for bubble-free introduction of a process gas into a liquid located in a reactor, wherein the gassing unit comprises at least: a first gas receiving chamber and, spaced therefrom, a second gas receiving chamber for receiving a process gas, the two gas receiving chambers being connected to one another via at least two two-dimensional, gas-conducting diffusion membranes comprising hollow fibers spaced apart from one another and at least partially fixed to one another; a receptacle for a gas supply on at least one of the gas receiving chambers; a receptacle for a shaft on at least one of the gas receiving chambers;
wherein the gassing unit for gassing the liquid in the reactor can be supplied with process gas via the gas supply receptacle, can be set into a rotational movement via the receptacle for the shaft and can form a convection flow within the reactor via the rotational movement of the gassing unit in the liquid. Furthermore, the present invention relates to a method for gassing a process liquid, a gas-liquid reactor comprising a gassing unit according to the invention, and the use of a gassing unit according to the invention for supplying biological cultures with process gases.
Claims
1. A gassing unit for bubble-free introduction of a process gas into a liquid located in a reactor, characterized in that the gassing unit at least comprises: a first gas receiving chamber and, spaced therefrom, a second gas receiving chamber for receiving a process gas, the two gas receiving chambers being connected to one another via at least two two-dimensional, gas-conducting diffusion mem-branes comprising hollow fibers spaced apart from one another and at least partially fixed to one another; a receptacle for a gas supply on at least one of the gas receiving chambers; a receptacle for a shaft on at least one of the gas receiving chambers; wherein the gassing unit for gassing the liquid in the reactor can be supplied with process gas via the gas supply receptacle, can be set into a rotational movement via the receptacle for the shaft and can form a convection flow within the reactor via the rotational movement of the gassing unit in the liquid.
2. Gassing unit according to claim 1, wherein the projections of the diffusion membranes onto the gas receiving chambers have a circular arc geometry.
3. Gassing unit according to claim 1, wherein the receptacle for the gas supply and the receptacle for the shaft are arranged at only one gas receiving chamber.
4. Gassing unit according to claim 1, wherein the two gas receiving chambers are each of cylindrical shape and are interconnected via one or more mechanical supports.
5. Gassing unit according to claim 4, wherein at least one retaining disk is arranged between the two gas receiving chambers on the mechanical support, which is set up to mechanically retain the diffusion membranes.
6. Gassing unit according to claim 4, wherein the mechanical support is adapted to transport process gas from the gas receiving chambers.
7. Gassing unit according to claim 1, wherein the area ratio of total hollow fiber cross-sectional area to the cross-sectional area of the gas receiving chamber is greater than or equal to 5% and less than or equal to 45%.
8. Gassing unit according to any one of the preceding claims, wherein the packing density of the diffusion membranes relative to the volume of the gassing unit, ex-pressed as the surface area of the hollow fibers divided by the volume of the gassing unit, is greater than or equal to 0.1 cm.sup.−1 and less than or equal to 7.5 cm.sup.−1.
9. Method for gassing a process liquid within a reactor, characterized in that the gas input is effected by a gassing unit according to claim 1.
10. The method of claim 9, wherein the rotational speed of the membrane surface at the outermost edge of the gassing unit is greater than or equal to 0.1 m/s and less than or equal to 5 m/s.
11. Gas-liquid reactor at least comprising an outer reactor shell, a drive unit, a gas supply and a gassing unit according to claim 1.
12. Gas-liquid reactor according to claim 11, wherein the reactor does not comprise a stirring unit other than the gassing unit.
13. Gas-liquid reactor according to claim 12, wherein at least one flow breaker is arranged between the reactor shell and a gas receiving chamber.
14. Use of a gas-liquid reactor according to claim 11 for supplying process gases to biological cultures suspended in a process solution or adhering to the reactor interior or to the gassing unit.
15. Use according to claim 14, wherein the biological cultures are adapted to produce foam-forming substances.
Description
IT SHOWS THE FIGURE
[0046] FIG. 1 an embodiment according to the invention of a gas receiving chamber in a top view;
[0047] FIG. 2 a further embodiment according to the invention of a gas receiving chamber in a top view;
[0048] FIG. 3 a side view of an embodiment according to the invention of a gassing unit;
[0049] FIG. 4 a front view of an embodiment according to the invention of a gassing unit;
[0050] FIG. 5 a schematic cut through a gassing unit according to the invention;
[0051] FIG. 6 a cut through a gassing unit according to the invention;
[0052] FIG. 7 a schematic cut through a reactor according to the invention with a gassing unit according to the invention;
[0053] FIG. 8 a schematic front view of a reactor according to the invention with a gassing unit according to the invention, including a possible convective flow profile;
[0054] FIG. 9 a schematic front view of a gassing unit according to the invention consisting of two gassing units connected in series;
[0055] FIG. 10 a schematic side view of a gassing unit according to the invention consisting of two gassing units connected in series;
[0056] FIG. 11 a schematic front view of a gassing unit according to the invention consisting of two serially connected gassing units with media supply;
[0057] FIG. 12 a schematic front view of a reactor according to the invention with two serially connected gassing units according to the invention with media supply;
[0058] FIG. 13 a schematic front view of a reactor according to the invention with two gassing units connected in series according to the invention, including a possible convective flow profile;
[0059] FIG. 14 a schematic exploded view of a gassing unit according to the invention.
[0060] FIG. 1 shows a schematic top view of a gas receiving chamber 1. The gas receiving chamber 1 is cylindrical and is divided into an inner area, which comprises a receptacle for a process gas 4 and/or a receptacle for a shaft 4. Via this receptacle 4, the gas receiving chamber 1 is supplied with both process gas and mechanical drive energy. The process gas is conducted from the receptacle 4 via the trapezoidal connecting pieces 5 into the actual gas receiving chamber 1. The gas receiving chamber 1 shows a closed surface 2, which is provided with corresponding recesses 3 for receiving the diffusion membranes (not shown in this figure). The diffusion membranes in the form of hollow fibers can be clamped or glued into the recesses 3, and the diffusion membranes extend into the interior of the gas receiving chamber 1, so that a continuous gas-conducting path can be made from the receptacle 4, via the connecting pieces 5, into the actual interior of the gas receiving chamber 1 up to the hollow fiber membranes. The recesses 3 can also be referred to as the diffusion membrane fixation surface 3. The geometry of the diffusion membrane fixation surface 3 determines the planar configuration of the diffusion membranes. In this embodiment, the diffusion membrane fixing surface 3 has an arcuate configuration, with the consequence that the hollow fibers fixed in these recesses have in total a likewise arcuate membrane surface. The upper and lower gas receiving chambers 1 can have a mirror-image configuration. However, it is also possible that one of the two gas receiving chambers 1 does not have a receptacle for further process means. During operation, the gas receiving chambers 1 can be protected from direct access by process media by covers on the lower or upper side.
[0061] FIG. 2 shows essentially the same arrangement compared to as FIG. 1 with the surface of the gas receiving chamber 2, the diffusion membrane fixing means 3, the receiving means for a process gas and/or a shaft 4, as well as the connection 5 of the gas receiving chamber with the gas receiving means 4. In contrast to FIG. 1, it is indicated at this point that individual cylindrical hollow fibers are inserted into the diffusion membrane fixing surface 3. Thus, it is made clear at this point that the surface is not a continuous flat membrane, but is formed from many individual hollow fibers that are offset from each other in both the X and Y directions so that they follow the arcuate configuration of the diffusion membrane fixation surface 3. In this respect, an arcuate geometry results for the diffusion membranes. In addition to the fixation of the hollow fibers in the two gas receiving chambers 1, the individual hollow fibers can also be mechanically fixed against each other (not shown in this figure). This additional fixation can be achieved, for example, by means of fibers woven or braided into the membrane perpendicular to the axis of symmetry of the hollow fibers. Thus, a lattice of hollow fibers and the fibers of the additional fixation is formed, which can be adjusted to the necessary mechanical load capacity of the diffusion membranes as a function of the number of further fixation points and as a function of the mechanical properties of the additional fibers.
[0062] FIG. 3 shows an embodiment of a gas supply unit 10 according to the invention. In this figure, the entire gas supply unit 10 can be seen. The gas supply unit 10 is supplied with the process media process gas and energy via a supply line 9. The supply line opens into the receptacle 4 for the gas supply/shaft of the first gas receiving chamber 1 (not shown). The gas receiving chamber 1 is provided with a top cover at this point. Extending from the gas receiving chamber 1 are the individual diffusion membranes 6, which extend in total from the first gas receiving chamber 1 (shown here at the top) to the lower gas receiving chamber 1. In this figure, the planar design of the diffusion membranes 6 can be seen in particular, which is achieved by a specific arrangement of hollow fibers. The diffusion membranes 6 extend from the first to the second gas receiving chamber 1 and are held in place in the center by a retaining disc 7. Thus, between the gas receiving chambers 1, the gas conduction of the individual diffusion membranes 6 is not interrupted. The diffusion membranes 6 can either only be held by the retaining disk 7, deflected from their original position or mechanically tensioned. The retaining disk 7 can thus change the orientation of the individual diffusion membranes 6, which of course exerts an influence on the achievable convection of the gassing unit 10. In this figure, a flow breaker 8 is also shown, which is arranged above the gassing unit 10 in the direction of the reactor head space. This flow breaker 8 is optional and can prevent vortex formation in the reactor liquid, especially at very high rotation speeds of the gassing unit 10. This can contribute to a further reduction in bubble formation.
[0063] FIG. 4 shows a front view of a gas supply unit 10 according to the invention. The gas supply unit 10 is supplied with the process media process gas and mechanical energy via a supply line 9. The supply line opens into the receptacle for the gas supply/shaft of the first gas receiving chamber 1 (not shown). Extending from the gas receiving chamber 1 are the individual diffusion membranes 6 which extend in total from the upper 1 to the lower gas receiving chamber 1. The diffusion membranes 6 extend from the first 1 to the second gas receiving chamber 1 and are held in place at the center by a retaining disk 7. In this figure, a flow breaker 8 is also shown, which is arranged above the gassing unit 10 in the direction of the reactor head space.
[0064] FIG. 5 shows an example of the media feed within a gas supply unit 10 according to the invention. The gas supply unit 10 is driven by a hollow shaft 9, which is connected to the gas receiving chamber 1 at the receptacle 4 for the gas supply/shaft. The shaft transports both the mechanical energy and the process gas to the gas receiving chamber 1. Via the receptacle 4 for the gas supply and the connection gas receptacle interior-gas receptacle, the gas is led into the interior gas receptacle 11. The individual hollow fiber membranes 6 are arranged on the gas receiving chamber 1 so as to extend into the inner gas receiving chamber 11. The hollow fiber membranes are thus supplied with process gas through the inner gas receiving chamber 11, which is conducted through the hollow fibers of the diffusion membranes 6 into the other gas receiving chamber 1. The process gas can pass from the hollow fibers of the diffusion membranes 6 into the process liquid, thus supplying the liquid with process gas. Both gas receiving chambers 1 are thereby additionally connected to each other via a mechanical support 12. This support can be used for other technical functions in addition to purely mechanical support. In this embodiment, the second (lower) gas receiving chamber 1 also comprises a receptacle 4 for the process gas. The process gas that has not diffused out of the membranes 6 is guided out of the gassing unit 10 via the support 12 in the form of a hollow shaft. The gassing unit 10 is thus operated in a “cross-flow” mode. In general, the process gas can be discharged as well as supplied via a central hollow shaft 12, which can also act as a mechanical support. In particular, the latter design can reduce the number of necessary connection points.
[0065] FIG. 6 shows, also like FIG. 5, the media flow within a gas supply unit 10 according to the invention. The gas supply unit 10 is supplied with process gas and/or mechanical energy by the receptacle 4. The receptacle 4 is connected to the gas receiving chamber 1, whereby the process gas is fed into the inner gas receiving chamber 11. The individual hollow fiber membranes 6 are disposed on and extend into the gas receiving chamber 1. Thus, the hollow fiber membranes 6 are supplied with process gas through the inner gas receiving chamber 11, which is conducted through the hollow fibers of the diffusion membranes 6 into the other gas receiving chamber 1. The process gas can pass from the hollow fibers of the diffusion membranes 6 into the process liquid, thus supplying the liquid with process gas. Both gas receiving chambers 1 are thereby additionally connected to each other via a mechanical support 12, which can optionally also guide process gas. In this embodiment, the second (lower) gas receiving chamber 1 also comprises a receptacle 4 for the process gas. The process gas that has not diffused out of the membranes 6 is guided out of the gassing unit 10 via a gas line in the mechanical support 12. In this embodiment, the gassing unit 10 can be operated in a “cross-flow” mode. In general, therefore, the supply 4 as well as the discharge of the process gas can be effected via a central mechanical support 12 in the form of a hollow shaft. In particular, the latter design can reduce the number of necessary connection points.
[0066] FIG. 7 shows a bioreactor 20 according to the invention with the gassing unit 10 according to the invention located therein. The reactor 20 is filled with a process liquid, the process liquid being present in the reactor 20 up to the process liquid level 21. The gassing unit 10 is held in and moved through the reactor 20 by the process gas/mechanical energy supply in the form of a hollow shaft 9. The further construction of the gassing unit 10 can be taken from the description for FIG. 5. It is also possible that further flow breakers or conductors 8 are arranged on the reactor walls 22 or in the liquid volume of the reactor 20 (not shown in this figure), whereby the convection of the process liquid can be influenced with this further flow breaker 8.
[0067] FIG. 8 shows one possibility for the design of a reactor 20 according to the invention with a gassing unit 10 according to the invention. In this figure, one possibility for the formation of convection flows within the reactor 20 is shown. The convection flows result from a simulation of the flow behavior as a function of the geometry of the reactor 20 and the gassing unit 10. In this figure, it can be seen that the gassing unit 10 leads to the formation of a very symmetrical convection flow, whereby the interior of the gassing unit 10 in particular is also actively flowed around by the process liquid. In particular, the latter can contribute to a particularly efficient introduction of process gas through the diffusion membranes 6 into the process liquid. The convection of the process liquid around the individual hollow fibers 6 in particular forms small gas bubbles, which are sheared off the surface of the hollow fibers 6 and can thus supply the process liquid with process gas. This also ensures that the bubble size on the surface of the hollow fibers is kept small.
[0068] FIG. 9 shows a serially connected gassing unit 30 consisting of two individual gassing units 10, which are coupled via a module coupling 31. Via the module coupling 31, both the process gas and the mechanical movement are transferred from the upper gassing unit 10 to the lower gassing unit 10. By interconnecting several gassing units 10, different reactor geometries and also sizes can be supplied with process gas very efficiently. The result is a design with as few connections as possible and a reliably predictable convection flow. This means that up-scaling to larger reactors 20 can easily be carried out, especially via series-connected gas supply units 30.
[0069] FIG. 10 shows the embodiment of FIG. 9 from another perspective.
[0070] FIG. 11 shows an example of the media feed within an arrangement of two gassing units 10 connected in series. The gassing unit 10 is driven by a hollow shaft 9, which is connected to the gas receiving chamber 1 at the receptacle for the gas supply/shaft 4. Via the receptacle for the gas supply 4 and the connection gas receptacle inner chamber gas receptacle 5, the gas is fed into via the individual hollow fiber membranes 6 into the other gas receptacle chamber 1. From this second gas receiving chamber 1, the remaining process gas can pass into the second gassing unit 10 via a module coupling 31. The module coupling 31 between the two gas supply units 10 enables both the transfer of the process gas and the transfer of the mechanical drive energy between the individual gas supply units 10.
[0071] FIG. 12 shows an embodiment of a reactor 20 according to the invention with two gassing units 30 connected in series, which consist of two individual gassing units 10. By connecting several gas supply units 10 in series, reactors 20 with a large aspect ratio in particular can also be reliably supplied with process gas.
[0072] FIG. 13 shows a possible flow profile of a reactor 20 equipped with two gassing units 30 connected in series. The result is a uniform convection of the process liquid both over the entire reactor area and within the series-connected gassing unit 30.
[0073] FIG. 14 shows an exploded view of a gas supply unit 10 according to the invention. The gas supply unit 10 can, for example, be driven and supplied with process gas by a hollow shaft (not shown in this figure), which is connected to the gas receiving chamber 1 at the receptacle 4. The shaft both provides the mechanical power to the unit and transports the process gas to the gas receiving chamber 1. The individual hollow fiber membranes 6 are arranged on the gas receiving chamber 1 so that they extend into the inner gas receiving chamber 11. The hollow fiber membranes are thus supplied with process gas through the inner gas receiving chamber 11, which is conducted through the hollow fibers of the diffusion membranes 6 into the other (lower) gas receiving chamber 1. The process gas can pass from the hollow fibers of the diffusion membranes 6 into the process liquid, thus supplying the liquid with process gas. Both gas receiving chambers 1 are thereby additionally connected to each other via a mechanical support 12. This support 12 can be used for other technical functions in addition to purely mechanical support. In this embodiment, the second (lower) gas receiving chamber 1 also comprises a receptacle 4 for process gas. The process gas that has not diffused out of the membranes 6 is led out of the gassing unit 10 again via the hollow shaft of the mechanical support 12. In this embodiment, the gassing unit 10 is thus operated in a “cross-flow” mode. In general, the process gas can be fed in and out via a central hollow shaft in the mechanical support 12, which is connected to the outer periphery of one or both gas receiving chambers 1 via receptacles 4. In particular, the latter embodiment can reduce the number of necessary connection points and contribute to a compact design. In addition, it can be seen in this embodiment that the individual gas receiving chambers 1 can be protected above and below by cover plates.
REFERENCE SIGN
[0074] 1 Gas receiving chamber [0075] 2 Surface area gas receiving chamber [0076] 3 Diffusion membrane fixation surface [0077] 4 Receptable for gas supply/shaft [0078] 5 Connection gas intake interior—gas intake [0079] 6 Diffusion membranes [0080] 7 Retaining disk [0081] 8 Flow breaker [0082] 9 Process gas/mechanical energy supply [0083] 10 Gassing unit [0084] 11 Inner gas receiving chamber [0085] 12 Support [0086] 20 Gas-liquid reactor [0087] 21 Process liquid level [0088] 22 Reactor shell [0089] 30 Serially arranged gassing units [0090] 31 Module coupling
