DE10021289A1 - Tank system for bulk goods consisting of small to very small solids that can be loaded with a combustible gas and a device for unloading the bulk goods - Google Patents

Abstract

The invention relates to a tank system for bulk material which can be loaded with a combustible gas, for example filled with hydrogen and which consists of fine to minute solids and to a device for discharging the bulk material. According to the invention, the filling volume of the tank (1) is subdivided into two separate sections (5, 6) which are hermetically sealed from one another, in such a way that the volumes of said sections can vary alternately in a reciprocal manner, between the value </= approximately zero >/= and the approximately maximum filling volume of the tank (1), and that the tank (1) is connected to a device for discharging the bulk material, which allows the discharged bulk material to be returned to said tank (1).

Description

The invention relates to a tank system according to the preamble of claim 1.

One of the storage options for hydrogen on board fuel cells Electric vehicles is the adsorption of hydrogen and in so-called nanotubes, a modification of graphite, the spherical carbon called "fullerene" large molecules is related. To use the adsorbed hydrogen in the fuel cells to be able to, he must desorb at preferably elevated temperature and then from the emptied nanotubes. Because the manufacture of the tube material is based on the tubes have to be maneuverable and significant cost reductions are not to be expected their discharge can be collected for reuse. Even if the tubes are mecha niche are relatively resilient, they still have to be treated very gently, so that as few of them break as possible when unloading.

The invention is therefore based on the object in the context of the tank system according to the invention First propose a tank that allows the unloaded bulk goods to be carefully and au also very space-saving, while the bulk material to be unloaded same tank is removed.

This problem is generally solved by the characterizing part of claim 1, and in particular ren by the characterizing parts of claims 2 to 4. While that with a burning bulk gas-laden bulk material is removed from the tank, the unloaded bulk material can be flow back the same tank because it has two hermetically separated departments possesses that move through the separating element - a highly flexible membrane or a longitudinal axial  pliable piston - in terms of their volumes alternately between the value "almost zero" and the almost total filling volume of the tank can be varied.

Furthermore, the invention proposes a device for unloading the bulk material, which it allows the bulk material to be handled extremely gently during the unloading process.

This problem is solved by the characterizing parts of claims 5-14.

Since the bulk goods mentioned above, for example the nanotubes, are very small - their length lies in the micrometer range and their diameter in the nanometer range - would be the separation of the emptying nanotubes from the gas using filters is extremely difficult. The filters would be quick be clogged, and the bulk material could only be removed from the filter material with great effort the. According to the invention, it is therefore basically proposed to separate the gas phase from the solid phase with a cyclone. The removal of the loaded bulk goods from the tank, its further transport into the cyclone and the return of the unloaded bulk Good in turn is done in the tank by appropriate pressure drops that differ Way can be generated.

For example, if you follow the path of the bulk material flow from the tank to the desorption point at one Tank system according to claim 5, you first encounter a valve if possible in connection with a pressure sensor for controlling and monitoring the tank system according to the invention. After that the bulk material flow passes through the first part of a heat exchanger, where it already receives heat from the processed gas stream. This is followed by the point where the bulk material flow reaches the desired one or necessary desorption temperature is heated. The heating in question can either be electrically or as a heat pump or even reali by a hydrogen flame be settled. The prevailing temperature is controlled by one or more temperature sensors profiled. The expansion caused by the heating of the hydrogen can be adjusted accordingly set pressure to be kept low.

After passing the second part of the heat exchanger, which the heat no longer needed If bulk material is withdrawn, it flows into a cyclone. According to the well-known Zyk principle, the gas and the bulk material are separated from each other. While the unloaded bulk goods in the designated section of the tank migrates, the gas flow is through a designated pipe line, if necessary with a fine screen and a throttle in connection with a pressure sensor sor is equipped, supplied to the consumer.  

In order to obtain a directed bulk flow, the desorption must work intermittently. To clarify this mode of operation, the individual stages of the cycle are described in detail in connection with the tank system according to FIG. 3.

In a tank system according to claim 5, various sensors are required, which together with a Control unit not shown and not shown the heating and the necessary valves or control the slide according to the cycle description according to the correct time.

The tank system described above works without pumps, which is an important requirement for is the gentle handling of the bulk material. Filters and sieves are also missing when separating the Gases from the solid phase.

Furthermore, a hydrogen gas stream that is partially branched off from the end of the cyclone can pass over a turbine in the tank with the loaded bulk material generate an overpressure such that thereby the loaded bulk material through another pipe for unloading into the cyclone is pressed. The turbine can be designed as an axial turbine; between them rigidly on the connected paddle wheels there may be heating elements that control the gas temperature increase to the required desorption temperature. The heating can advantageously be electrical be designed. However, a heat pump or something would also be conceivable here, for example serstoffilamme. The blades of the turbine are attached to the thermi according to aerodynamic principles cal expansion of the gas flow adjusted by a factor of about 3.7. This factor can go through Working pressure increase can be reduced. Further details of the tankan according to the invention location are detailed in the illustration description.

The inventive device for unloading the bulk material is summarized The following advantages: no pumps, no filters or sieves and - as required - continuous desorption operation is also possible.

A radial turbine can also be used as a turbine within the scope of the invention moderate tank system.

In addition, a simple mechanical pump can be used in a non-continuous operation of the tank system according to the invention, as is explained, for example, in the following description of the figures with reference to FIG. 5.

Finally, it could also make sense to transport the bulk goods - especially for stationary ones ren systems - to realize by known vibrating devices; for mobile systems - such as for motor vehicles, however, this type of bulk goods transport should be less be suitable, although here too it cannot be completely ruled out.

In order to meet the legal requirements, the tank system according to the invention should be ge be completely hermetically sealed from their surroundings in order to prevent hydrogen leaks avoid serious damage.

The figures illustrate the invention with reference to FIGS. 1 to 5. Show it:

Fig. 1 ge a tank having a membrane for use in an inventive Tankanla,

Fig. 2 shows a tank with a piston system also usable in a tank according to the invention,

Fig. 3 shows a tank system for unloading loaded with combustible gas bulk material from kleins th solids,

Fig. 4 shows a tank system for the continuous discharge of bulk material according to Fig. 3,

Fig. 5 is a pump system for required use in tanks according to FIGS. 3 and 4.

According to the invention, the tank 1 according to FIG. 1 is divided longitudinally by a flexible membrane 3 into two separate sections 5 and 6 . If the department 5 is filled with bulk material made of, for example, hydrogen-enriched nanotubes, the membrane 3 approaches the lower inner region 9 of the tank 1 with increasing filling until it is completely in contact; in this state, the department 5 of the tank 1 whose almost 100% fill volume can be used. The same applies in reverse for section 6 of tank 1 . In this case, the membrane 3 lies completely on the upper inner region 16 of the tank 1 as soon as the compartment 6 is filled. The pipeline 10 of the tank 1 leads according to the arrow direction 11 to a discharge device 12 or 13 according to FIGS. 3 and 4. From the discharge device 12 or 13 , the unloaded bulk material is returned through the pipeline 14 according to the arrow direction 15 into the tank 1 led, namely in its department 6 . Characterized in that at the same time the emptying of the division 5 takes place through the pipeline 10 , the membrane 3 of the tank 1 according to FIG. 1 moves upwards with the filling of the department 6 until it is in the department's 100% filling condition 6 comes to rest on the upper inner surface 16 of the tank 1 . In this state, department 5 is completely empty. It can be filled again with loaded bulk material for "refueling" after the unloaded bulk material has been removed from the department 6 , after which the previously described unloading process can begin again. The pipe 17 according to FIG. 1 is used according to the direction of the arrow 18 to generate an internal pressure in the section 5 in order to start and maintain its emptying flow of the bulk material through the pipe 10 .

Fig. 2 shows a tank 2 in the shape of a cylinder (lying), which is equipped in its interior with a piston 4 which divides the interior of the tank 2 into the two sections 7 and 8 . The piston 4 can be connected to a piston rod 19 , which allows the piston 4 to move accordingly from the outside in accordance with the double arrow direction 20 and, if necessary, also to control it in its movement sequence by means of suitable auxiliary devices. In a section 7 fully loaded with bulk material, for example, from nanotubes enriched with a combustible gas, the piston 4 bears against the inner end face 21 of the tank 2 (right in the picture). From the division 7 then corresponds to almost the entire filling volume of the tank 2 , and so this can be used almost completely for receiving enriched bulk material. If now the bulk material from the department 7 is gradually passed through the pipeline 22 in accordance with the arrow direction 23 of a discharge device, for example the device 13 according to FIG. 4, the piston 4 can move to the extent that the removal of the bulk material from the department 7 , move to the left towards the inner end face 24 of the tank 2 . During this process, the volume of department 8 increases to the same extent as the volume of department 7 decreases. The department 8 is thus available from the start of the unloading process for receiving unloaded bulk material, which can be supplied to it through the pipeline 25 , which connects the tank 2 to the unloading device 12 or 13 , in accordance with the direction of the arrow 26 . This is possible until the piston 4 comes to rest on the end face 24 of the tank 2 . In this state the tank 2 is "empty"; the section 7 can then be filled again with a combustible gas-enriched bulk material after the section 8 has been emptied and the piston 4 has been moved to the right until it touches the inner end face 21 of the tank 2 .

The pipeline 27 is, analogously to the pipeline 17 according to FIG. 1, a pressure supply line. The direction of arrow 28 illustrates the direction of pressure supply. Fig. 3 shows a tank 1 , the device via the pipes 10 and 14 with a Entladungseinrich 12 is connected. The tank 1 here is only missing the pipe 17 compared to the presen- tation in FIG. 1. The pipe 10 ultimately leads to a cyclone 29 according to the direction of the arrow 11 . A heater 31 is provided in the area 30 of the pipeline 10 ; In addition, the initial diameter 32 of the pipeline 10 is expanded to the larger diameter 33 in the area 30 up to the entry into the cyclone 29 . The heating unloads the bulk material. The mixture of discharged bulk material and the combustible gas then flows into the cyclone 29 , where it is separated in a manner known per se. The bulk material falls out of the cyclone 29 downwards due to its considerably greater specific weight than the gas and can be fed to the section 6 of the tank 1 via the pipeline 14 . At the same time, the combustible gas is fed via the pipeline 34 to its use in a fuel cell or in an internal combustion engine. Since the gas is still very warm due to the heating of the bulk material after the separation from it, it can be economical to provide a heat exchanger which in its part 35 surrounding the pipe 34 absorbs as much heat as possible from the gas flowing out and this via the pipe 36 and its part 37 , which surrounds the pipeline 10 even before its area 30, into the pipeline 10 or into the bulk material therein. The valves 38 , 39 and 40 serve to regulate the discharge device 12 .

In the case of the discharge device 12 according to FIG. 3, the pressure supply pipelines 18 and 39 according to FIGS . 1 and 2 for the tanks 1 and 2 are not required, since the pressure required to start and maintain the discharge process is otherwise generated and maintained is obtained. In order to obtain a directed and manageable, controllable bulk material flow, the desorption of the gas adsorbed on the bulk material must be carried out intermittently. To clarify this, the individual stages of the cycle are described below.

First, the boiler room - that is, the interior of the pipeline 10 in the area 30 - is filled with fresh, loaded bulk material. Valve 40 is closed, as are valves 39 and 38 . Then the heater 31 is turned on, causing the pressure in the cyclone to rise. The throttle valve 38 is now opened somewhat. In the resulting gas flow, a vortex forms in the cyclone, through which the bulk material discharged by the heating is separated. Now valve 38 is closed again and valve 39 is opened. The overpressure still prevailing in the cyclone 29 presses against the membrane 3 in the tank 1 and is thus able to press fresh bulk material into the pipeline 10 . After the valve 39 has been closed , the valve 40 is opened until there is sufficient fresh, still loaded bulk material in the boiler room, where the discharge process then begins immediately. This allows the cycle described above to begin again.

In the tank system according to the invention, shown schematically in FIG. 3, various sensors including a control device for the timely regulation or control of the heating and the valves are required for the mutual coordination of the individual method steps - of course for a relevant specialist. In addition, it may prove necessary in the implementation of the system, other, for. B. optical sensors and if necessary also provide buffer containers for the bulk material.

The tank system according to the invention advantageously works without pumps, which we quite is a prerequisite for gentle treatment of sensitive bulk goods. The invention also avoids any filters, sieves or the like for separating the gas from the solid phase. With the smallness of the bulk particles, for example the nanotubes, would be, for example, filters with a sufficient lifespan and necessary degrees of separation hardly cost-effective or economical to manufacture.

If necessary, a pressure required therein can be generated via the piston rod 19 and the piston 4 in the tank 2 in the drainage 7 thereof.

The discharge device 13 according to FIG. 4 is equipped with a tank 1 according to FIG. 1. Furthermore, it works fully continuously, thanks to an axial turbine 41 , which generates a pressure via the pipeline 17 in the section 5 of the tank 1 and also maintains this pressure. This pressure causes the bulk material already discharged in section 5 to flow out, since the turbine 41, thanks to its heating device 42, brings the required heat in addition to the pressure into section 5 . From this, the mixture of discharged bulk material and a combustible gas flows through the pipeline 10 into a cyclone 43 . There, in turn, the gas is separated from the unloaded bulk material in a manner known per se. The gas is supplied through tubing 44 for use in a fuel cell or in an internal combustion engine. The unloaded bulk material is fed from the cyclone 43 via the pipeline 14 to the department 6 of the tank 1 . The pipes 10 and 17 are connected via a heat exchanger 45 , which transfers excess heat from the pipe 10 into the pipe 17 . A valve 46 in the pipeline 44 allows the amount of gas to be removed to be regulated.

FIG. 5 shows a pump system which, if necessary, can be used in tank systems according to FIGS. 3 and 4 for transporting the bulk material. A tube 47 with a round, square or rectangular cross section is equipped with the two flap valves 48 and 49 , which are kept open in their basic position with a weak spring pressure, not shown here. If the piston 50 in the laterally connected to the tube 47 moves the cylinder 56 downward in the direction 51 , the valve 48 closes against its spring pressure and its stop 58 and the contents of the space 52 can move in the direction 53 through the open fene Valve escape. If the content is bulk material within the scope of the invention, it can easily be imagined that it can be transported intermittently in this way with the present pumping device in the direction 11 according to FIG. 3 if it is with its tube 47 in the pipeline 10 of the tank systems according to FIGS . 3 and 4 is integrated accordingly.

If the piston 50 is moved in the cylinder 56 in the direction of the arrow 54 , the valve 49 closes against its spring pressure and its stop 57 , while the flap of the valve 48 lifts off its stop 58 , so that now further bulk material in the direction of the arrow 55 can flow into space 52 .

The closable openings 59 and 60 in the left end wall of the tank 1 according to FIG. 1 are used for filling and emptying the departments 5 and 6 of the tank 1 as required.

Correspondingly closable openings are also provided for a tank 2 according to FIG. 2 in order to be able to load and / or unload the departments 7 and 8 there with bulk material if necessary.

The same also applies to the systems shown in FIGS. 3 and 4, where the openings 59 and 60 are to be provided accordingly in the tank 1 used here ver.

Furthermore, it may be necessary, taking into account the regulations regarding the handling of hydrogen, to hermetically seal the tank systems 12 and 13 according to FIGS . 3 and 4 with respect to their surroundings. This can prevent damage in the event of unexpected hydrogen leakage.

The membrane 3 and the piston 4 including its piston rod 19 can also be used for level measurements or for level indicators of the tanks 1 and 2 . For this purpose, the membrane 3 would have to be equipped with suitable sensors, for example with optical sensors, while in the tank 2 its current fill level can be read directly at the position of the piston rod 19 .

Claims (13)

1.Tank system for bulk goods consisting of small to very small solids, which can be loaded with a combustible gas - such as spherical solids with pore or channel structures for storing gases according to the German patent (patent application 100 07 544.4) or nanotubes, for example with Are filled with hydrogen - with a device for unloading the bulk material, characterized in that the filling volume of the tank ( 1 , 2 ) by a flexible and / or movable element ( 3 , 4 ) in two hermetically separated compartments ( 5 , 6 and 7 , 8 ), whereby the element ( 3 , 4 ) allows the compartments ( 5 , 6 and 7 , 8 ) to be reciprocally reciprocal in volume between the value "almost zero" and the almost total filling volume of the tank ( 1 , 2 ) are variable, and that the tank ( 1 , 2 ) is connected to a device known per se ( 12 , 13 ) for unloading the bulk material, which, however, s It is formed that the unloaded bulk material can be returned to the tank ( 1 , 2 ). 2. Tank system according to claim 1, characterized in that the tank ( 1 , 2 ) is divided longitudinally by a flexible membrane ( 3 ) into two hermetically separated sections ( 5 , 6 ). 3. Tank system according to claim 1, characterized in that the cylindrical tank ( 2 ) is divided by a piston ( 4 ) into two hermetically separated sections ( 7 , 8 ). 4. Tank system according to claim 3, characterized in that the piston ( 4 ) is connected to an outwardly leading piston rod ( 19 ) which can be used for control purposes. 5. Tank system according to claims 1 and 2, characterized in that the section ( 5 ) of the tank ( 1 ) according to FIG. 3 is connected via a pipe ( 10 ) to a cyclone ( 29 ), that another pipe ( 14 ) connects the cyclone ( 29 ) to the compartment ( 6 ) of the tank ( 1 ), that a heater ( 31 ) is provided in the funnel-shaped area ( 30 ) of the pipeline ( 10 ), that the cyclone ( 29 ) a pipeline ( 34 ) for conveying the combustible gases and that the pipes ( 10 , 14 , 34 ) are provided with valves ( 40 , 39 , 38 ). 6. Tank system according to claim 5, characterized in that the pipes ( 34 ) and ( 10 ) are connected to one another via a heat exchanger ( 35 , 36 , 37 ). 7. Tank system according to claims 5 and 6, characterized in that in the pipeline lines ( 10 , 14 , 34 ) in addition to the valves ( 40 , 39 , 38 ) sensors are also provided, which in connection with a suitable control device in the Are able to regulate or control the tank system according to the Invention. 8. Tank system according to claims 1 and 2 with a device for the continuous unloading of the bulk material, characterized in that the department ( 5 ) of the tank ( 1 ) according to FIG. 4 via pipes ( 10 and 17 ) with a cyclone ( 43 ) is connected, while this is connected via a pipeline ( 14 ) to the department ( 6 ) of the tank ( 1 ), that in the pipeline ( 17 ) an axial turbine ( 41 ) with a heater ( 42 ) is provided for Building up a pressure in the direction of the arrow ( 18 ), and that finally the cyclone ( 43 ) is connected to a pipe ( 44 ) with a valve ( 46 ) for passing on the combustible gases. 9. Tank system according to claim 8, characterized in that the pipes ( 10 ) and ( 17 ) are connected to one another by a heat exchanger ( 45 ). 10. Tank system according to claims 5 to 9, characterized in that in the Rohrleitun gene ( 34 , 44 ) fine screens are provided. 11. Tank system according to one or more of claims 5 to 10, characterized in that a pump system according to FIG. 5 is used to transport the bulk material. 12. Tank system according to one or more of claims 5 to 10, characterized in that who uses known vibrating systems to transport the bulk material the. 13. Tank system according to claims 5 to 12, characterized in that for regulation or control the bulk material flow in a manner known per se as many valves as desired, Sliders and sensors are provided.