Spindle cartridges and methods for producing tubular ceramic structures

Abstract

The present teachings relate to cartridges and methods for making tubular ceramic structures that can be tubular ceramic green bodies, which are convertible to tubular solid oxide fuel cells.

Description

[0001] SPINDLE CARTRIDGES AND METHODS FOR PRODUCING TUBULAR CERAMIC STRUCTURES

[0002] CROSS-REFERENCE TO RELATED APPLICATION

[0003] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 512,715, filed July 10, 2023, the entire disclosure of which is hereby incorporated by reference in its entirety for all purposes.

[0004] FIELD

[0005] The present teachings relate to spindle cartridges and methods for making tubular ceramic structures that can be tubular ceramic green bodies, which are convertible to tubular solid oxide fuel cells.

[0006] BACKGROUND

[0007] Tubular ceramic structures are known for use as heat exchangers where corrosive liquids or gases are encountered, recuperators, catalyst bodies, as components of fuel cells, particularly solid oxide fuel cells (SOFCs), and in a variety of other applications. SOFCs have gained attention in recent years for their green energy production as well as for portable and distributed means for providing electricity in remote places or residential applications. Among the various designs, micro- or macro-tubular SOFCs provide a number of advantages.

[0008] Tubular ceramic structures for SOFCs can be produced using the methods described in U.S. Patent No. 9,542,548, using a rotating mandrel-spindle assembly. Such a technique is capable of producing a tubular ceramic structure over a broad range of wall thicknesses, i.e., from the very thin to the very thick, does not require close attention to and control of the conditions of drying, is readily capable of altering or modifying the composition of the tubular product for a defined portion thereof, and does not require the use of a tubular substrate which is destined to become a permanent component of the product. Although the techniques described therein are effective, commercial SOFC unit production requires thousands of tubular SOFCs, especially when using bundles of micro- or macro-tubular SOFCs.

[0009] Thus, there is a need to improve the efficiency and consistency of making tubular ceramic green bodies for use as tubular solid oxide fuel cells. SUMMARY

[0010] Methods of preparing tubular ceramic structures such as tubular ceramic green bodies or tubular SOFCs can include applying different ceramic-forming layers about a rotating spindle to form a tubular ceramic green body as referenced above and described herein. FIG. 1 A depicts a side view of a spindle 2 held between two end pieces 4, 4’ that can be used in such a preparation technique (rotation mechanism not shown). In an attempt to create more tubular SOFCs per spindle, the length of the spindle can be increased so that the longer formed tubular ceramic green bodies can be cut into appropriate lengths for the final product. However, as the length of the spindle increases, and depending on its diameter, materials of construction, and rotational speed (e.g., revolutions per minute (rpm)), so does the “wobble” of the spindle near its length midpoint. That is, when rotating at a sufficient speed, depending on the spindle properties, the midpoint of its length will deviate from the longitudinal axis 6 depicted as a dotted line in FIGS. 1 A to 1C. Accordingly, a ceramic-forming composition will not be evenly applied from a fixed- distance printer head 8 that moves back and forth along the longitudinal direction 9 above the spindle thereby causing deviations in the resulting tubular ceramic green bodies.

[0011] It has now been discovered that a multiple spindle cartridge can eliminate the “wobble” while also providing a high throughput of tubular ceramic green bodies or other tubular structures that can benefit from the design of the present teachings. In particular, the cartridge of the present teachings includes multiple spindles, each of which is comprised of sub-spindles along a longitudinal axis thereby eliminating any wobble or deviation from their respective longitudinal axis. The spindles made of sub-spindles, which can interconnect, and can be rotated at the same rate for uniform application of the ceramic-forming layers thereby producing a consistent product.

[0012] Furthermore, current methods require the operator to remove the green bodies from a spindle that may comprise of two or more green bodies. The technician must handle each green body by sliding them off the spindle and then prepare them for the next steps in the process. The individual spindle design allows for users to transfer the spindle assembly between processes without touching the green body of the cell. The design depicted herein illustrates features that would allow for interfacing with other equipment in the process, eliminating the need to touch the green bodies throughout the process.

[0013] Moreover, each sub-spindle is able to be independently removed from the multiple spindle cartridge, permitting defective or out of specification tubular ceramic green bodies to be removed and / or replaced before further processing, for example, firing to create the ceramic SOFCs.

[0014] Thus, in one aspect, the present teachings generally provide a multiple spindle cartridge for making tubular ceramic structures comprising: a frame comprising a first side and a second side, wherein the first side of the frame is parallel to the second side of the frame secured by a support structure between the first side and the second side; wherein the first side of the frame comprises a series of spindle engaging mechanisms and the second side of the frame comprises a series of corresponding spindle engaging mechanisms opposite the series of spindle engaging mechanisms along the first side of the frame; and a plurality of spindles, being parallel to and in the same plane as each other, wherein one end of each of which is engaged in the spindle engaging mechanism on the first side of the frame and the other end of each of which is engaged in the respective corresponding opposite spindle engaging mechanism on the second side of the frame, wherein each spindle comprises two or more sub-spindles, the two or more subspindles of a respective spindle being in axial longitudinal alignment from the spindle engaging mechanism on the first side to the corresponding opposite spindle engaging mechanism on the second side, wherein each sub-spindle is removably and operably connected to another sub-spindle(s) of the respective spindle through a support bar, wherein the support bar is parallel to the first side and the second side and has respective corresponding sub-spindle engaging mechanisms on opposite sides; wherein each of the sub-spindles is independently removeable from the multiple spindle cartridge. In some embodiments, the plurality of spindles are evenly spaced apart.

[0015] In another aspect, the present teachings generally provide a system for making tubular ceramic structures, the system comprising a multiple spindle cartridge as described herein; and a printer assembly comprising a printer head positioned above a spindle or support tube, if present, wherein the printer head is adapted to move linearly along the longitudinal axis of the spindle from the first side to the second side of the frame and from the second side to the first side, and perpendicularly to cover different spindles.

[0016] Systems of the present teachings can include a multiple spindle cartridge as described herein including a rotation mechanism and a printer assembly that is adapted to apply ceramicforming layers onto the rotating spindles. The printer assembly can include a single printer head, but can include two or more printer heads, for example, four printer heads. Of course the efficiency of the process is enhanced with more printer heads. The printer head(s) can move along the longitudinal direction over a spindle applying ceramic-forming layers on the rotating spindle or mandrel component of a mandrel-spindle assembly or on a previously applied ceramic-forming layer. The printer head(s) can move perpendicularly and diagonally for application to each of the different spindles and for printing different patterns on the layer being applied, for example, a serpentine pattern.

[0017] A multiple spindle cartridge and associated systems can also include a controller, which contains computer software program(s) and appropriate hardware for automating the operation of the multiple spindle cartridge and associated systems. The controller can assist in operating the multiple spindle cartridge and associated systems effectively and efficiency for maximum consistency of product as well as high throughput.

[0018] Another aspect of the present teachings is methods of using the multiple spindle cartridge to form tubular ceramic structures where such methods include applying ceramic-forming layer(s) to the rotating spindles.

[0019] In this aspect, the present teachings generally provide a method using a multiple spindle cartridge of the present teachings to produce a tubular ceramic structure such as a tubular ceramic green body, the method generally comprising rotating the plurality of spindles, wherein the spindles comprise a mandrel component; and applying one or more of an ceramic-forming layers on a mandrel exterior to and in contact with the sub-spindles or on an already applied ceramic-forming layer on the sub-spindles of the multiple spindle cartridge.

[0020] The foregoing as well as other features and advantages of the present teachings will be more fully understood from the following figures, description, and claims.

[0021] DESCRIPTION OF THE DRAWINGS

[0022] It should be understood that the drawings described below are for illustration purposes only. Like numerals generally refer to like parts. The drawings are not necessarily to scale, with emphasis generally being placed upon illustrating the principles of the present teachings. The drawings are not intended to limit the scope of the present teachings in any way.

[0023] FIGS. 1 A-1C are schematic diagrams of a side view of showing a spindle at rest (FIG. 1A) and in rotation (FIGS. IB and 1C).

[0024] FIG. 2 is a schematic diagram of a top view of an embodiment of a multiple spindle cartridge of the present teachings. FIGS. 3A and 3B are schematic diagrams of an embodiment of a sub-spindle assembly (or simply referred to herein as a “sub-spindle”) of the present teachings. FIG. 3 A is a perspective view of a sub-spindle including a support tube and two end collars. FIG. 3B is an exploded side view of a same sub-spindle assembly.

[0025] FIGS. 4 A and 4B are schematic diagrams of cross-sectional side views of embodiments of a support bar and the ends of two sub-spindles of the present teachings engaged with subspindle engaging mechanisms where FIG. 4A depicts a U-shaped spindle end that mechanically interfaces and engages with a post partially across or across a connection tube in a bore through the support bar and FIG. 4B depicts spring loaded sub-spindle engaging mechanisms in a bore through the support bar.

[0026] FIGS. 5A-5D are schematic diagrams of a cross-sectional side view of a sub-spindle assembly of the present teachings showing a multiple collar end pieces or an even and an uneven edge projection. FIG. 5 A shows the outer collar in its retracted position and FIG. 5B shows the outer collar in its expanded position creating a mask for another ceramic-forming layer. FIG. 5C shows a single collar with an even edge projection protruding toward the mid-line of the subspindle thereby forming a mask. FIG. 5D shows an uneven triangular masking device that rotates with the spindle thereby forming a triangular section devoid of ceramic forming layers when the masking device is in place and forming an end of the tube that schematically looks like that in FIG. 5E.

[0027] FIG. 6A is side view of a sub-spindle assembly mounted between two support bars housing the spring loaded sub-spindle engaging mechanisms. Generally centered under the subspindle assembly is a scrapper or blade. FIG. 6B is a longitudinal cross-section of FIG. 6A along line A-A showing the positioning of the scrapper or blade below the support tube of the subspindle assembly.

[0028] FIG. 7 is a schematic diagram of a top view of an embodiment of a system of the present teachings including a multiple spindle cartridge and two printer heads.

[0029] DETAILED DESCRIPTION

[0030] It now has been discovered that there are devices, systems and methods for commercially producing tubular ceramic green bodies that can be converted into tubular SOFCs such as micro- and macro-tubular SOFCs for fuel cell bundles. The cartridge of the present teachings includes multiple spindles, each of which is comprised of sub-spindles along a longitudinal axis thereby eliminating any wobble or deviation from their respective longitudinal axis. The spindles made of sub-spindles, each interconnected, can be rotated at the same rate for uniform application of the ceramic-forming layers and consistent product.

[0031] In some embodiments, the multiple spindles can rotate at the same speed and in the same direction as adjacent spindles. In certain embodiments, the spindles can rotate opposite of the adjacent spindles to account for the longitudinal spray path of the print head.

[0032] Moreover, each sub-spindle is able to be independently removed from the multiple spindle cartridge, permitting defective or out of specification tubular ceramic green bodies to be removed and / or replaced before further processing, for example, firing to create the ceramic SOFCs, Replacing sub-spindles with out of specification green bodies with ones that are in specification can create a multiple spindle cartridge with all sub-spindles meeting specifications for further processing. The out of specification sub-spindles can be recycled for further use.

[0033] In addition, the sub-spindles can include annular collars at each end that can act as a mask, for example, for the ends of the ceramic-forming layers of a tubular ceramic green body. In some embodiments, the sub-spindles have a second annular collar outside of the first annular collar, where the second annular collar can have an elongation member that can be controlled to elongate at a determined time, for example, for the last layers of the tubular ceramic green body to provide another mask such as for an electrolyte-forming layer. In this way, when finalized, the underlying anode layer and any interface layer can be exposed without further processing.

[0034] The systems and methods of the present teachings can include a multiple spindle cartridge as described herein and a printer assembly that is adapted to apply ceramic-forming layers onto the rotating spindles / sub-spindles. The printer assembly can include a single printer head, but can include two or more printer heads, for example, four printer heads for reducing the overall processing time for a cartridge of multiple spindles. A cartridge of spindles can have four, six, eight, ten, or more spindles, each including two, three, four or more sub-spindles.

[0035] Moreover, the systems of the present teachings can include a controller for computer related operation of the methods described herein.

[0036] To facilitate an understanding of the present teachings, a number of terms and phrases are defined below.

[0037] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Throughout the application, where compositions are described as having, including, or comprising specific components, or where processes are described as having, including, or comprising specific process steps, it is contemplated that compositions of the present teachings also consist essentially of, or consist of, the recited components, and that the processes of the present teachings also consist essentially of, or consist of, the recited process steps.

[0038] In the application, where an element or component is said to be included in and / or selected from a list of recited elements or components, it should be understood that the element or component can be any one of the recited elements or components, or the element or component can be selected from a group consisting of two or more of the recited elements or components.

[0039] Further, it should be understood that elements and / or features of a composition, an apparatus, or a method described herein can be combined in a variety of ways without departing from the spirit and scope of the present teachings, whether explicit or implicit herein. For example, where reference is made to a particular structure, that structure can be used in various embodiments of apparatus of the present teachings and / or in methods of the present teachings, unless otherwise understood from the context. In other words, within this application, embodiments have been described and depicted in a way that enables a clear and concise application to be written and drawn, but it is intended and will be appreciated that embodiments may be variously combined or separated without parting from the present teachings and invention(s). For example, it will be appreciated that all features described and depicted herein can be applicable to all aspects of the invention(s) described and depicted herein.

[0040] It should be understood that the expression “at least one of’ includes individually each of the recited objects after the expression and the various combinations of two or more of the recited objects unless otherwise understood from the context and use. The expression “and / or” in connection with three or more recited objects should be understood to have the same meaning unless otherwise understood from the context.

[0041] The use of the term “include,” “includes,” “including,” “have,” “has,” “having,” “contain,” “contains,” or “containing,” including grammatical equivalents thereof, should be understood generally as open-ended and non-limiting, for example, not excluding additional unrecited elements or steps, unless otherwise specifically stated or understood from the context.

[0042] The use of the singular herein, for example, “a,” “an,” and “the,” includes the plural (and vice versa) unless specifically stated otherwise. Where the use of the term “about” is before a quantitative value, the present teachings also include the specific quantitative value itself, unless specifically stated otherwise. As used herein, the term “about” refers to a ±10%, ±5%, ±3%, ±2%, or ±1% variation from the nominal value unless otherwise indicated or inferred.

[0043] Where a percentage is provided with respect to an amount of a component or material in a structure or a composition, the percentage should be understood to be a percentage based on weight, unless otherwise stated or understood from the context.

[0044] Where a molecular weight is provided and not an absolute value, for example, of a polymer, then the molecular weight should be understood to be an average molecule weight, unless otherwise stated or understood from the context.

[0045] It should be understood that the order of steps or order for performing certain actions is immaterial so long as the present teachings remain operable. Moreover, two or more steps or actions may be conducted simultaneously.

[0046] At various places in the present specification, numerical values are disclosed in groups or in ranges. It is specifically intended that the description include each and every individual subcombination of the members of such groups and ranges and any combination of the various endpoints of such groups or ranges. For example, an integer in the range of 0 to 40 is specifically intended to individually disclose 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40, and an integer in the range of 1 to 20 is specifically intended to individually disclose 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.

[0047] The use of any and all examples, or exemplary language herein, for example, “such as” or “including,” is intended merely to illustrate better the present teachings and does not pose a limitation on the scope of the invention unless claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the present teachings.

[0048] Terms and expressions indicating spatial orientation or altitude such as “upper,” “lower,” “top,” “bottom,” horizontal,” “vertical,” and the like, unless their contextual usage indicates otherwise, are to be understood herein as having no structural, functional or operational significance and as merely reflecting the arbitrarily chosen orientation of the various views of apparatus, devices, components, and / or features of the present teachings that may be illustrated in certain of the accompanying figures. As used herein, “mandrel” or “mandrel component” refers to a heat shrinkable tube, a fugitive tube or a coating on a spindle, the external surface of which corresponds to the internal surface of the tubular ceramic green body to be produced and the internal surface of which defines a bore, the spindle or support tube being in close fitting but removeable contact therewith. A mandrel can also be present on a support tube, if in use.

[0049] The expression “ceramic-forming layer” refers to generally any of the “-forming layers” as described herein, for example, an anode-forming layer, an interface-forming layer, an electrolyte-forming layer, an active catalyst-forming layer, and an inert-forming layer. The ceramic composition of ceramic-forming layer can also include a “cermet,” where a ceramic is mixed with a reducible metal oxide such as nickel oxide, copper oxide, iron oxide, and / or other transition metal oxides. Precious metals can also be incorporated into a ceramic-forming layer. After the tubular ceramic green body is formed and fired, the resulting body can be exposed to hydrogen at a predetermined temperature required to reduce the incorporated metal oxide phase thereby producing a “cermet.” In addition, as used herein, a “ceramic composition” can includes these components.

[0050] In these terms, the “-forming layer” refers to the slurry of ceramic composition that is applied to the rotating mandrel or to a prior applied layer and, in particular, to an amount of solvent that remains associated with the ceramic while additional layers are applied. In some embodiments, only solvent can be printed or sprayed onto an already formed ceramic-forming layer or ceramic green body.

[0051] It should be understood that the layers are generally applied with the anode layer first, followed by an interface layer and then finally the electrolyte layer. However, this basic structure can vary by the inclusion of intermittent inert layers and active catalyst layers. That is, an inert layer or an active catalyst layer can be the first layer, followed by other such layers or an anode layer. The anode layer can include inert layers and active catalyst layers interspersed therein, which can be similar for the interface layer including between the interface layer and the electrolyte layer. The anode-forming layer and the interface-forming layer can also include layers of different elemental composition, for example, layers with different percentages of and / or different ceramics, metal oxides and precious metals than in previously applied layers. In certain embodiments, the anode layer and its components do not require an interface layer in between the electrolyte layer. Moreover, the present teaching include a tubular inert structure, for example, thin walled ceramic tubes for a reformer and / or a cathode heat exchanger. The “layers” as described herein can be thinner in a range of about 2 microns to about 5 microns to a thicker layer, which can be in a range of about 50 microns to about 800 microns, or 100 microns to about 500 microns. The complete tubular ceramic green body can be in a range of about 150 microns to about 1200 microns, for example, from about 200 microns to about 1100 microns, or from about 500 microns to about 1000 microns, or from about 750 microns to about 900 microns. Of course the layers and complete tubular ceramic body can be thinner or thicker depending on the particular application and design of tubular structure is desired.

[0052] As described herein and in reference to FIG. 2, in one aspect, the present teachings provide a multiple spindle cartridge 10 for making tubular structures such as tubular ceramic structures. The multiple spindle cartridge includes a frame 12 having a first side 14 and a second side 16 , where the first side of the frame is parallel to the second side of the frame secured by support structures 18, 18’ between the first side and the second side, for example, rigid bars connected to the first and second sides forming a rectangular or square shape when viewed from above.

[0053] The first side 14 of the frame 12 includes a series of spindle engaging mechanisms 20, 20’, 20”, etc. The second side 16 of the frame 12 includes a series of corresponding spindle engaging mechanisms 22, 22’, 22”, etc. , which are opposite the spindle engaging mechanisms on the first side. Consequently, a plurality of spindles 24 can be parallel to and in the same plane as each other when positioned in the multiple spindle cartridge. Indeed one end of a spindle 26 is engaged in a spindle engaging mechanism on the first side of the frame and the other end of the spindle 28 is engaged in the respective corresponding spindle engaging mechanism on the second side of the frame. The plurality of spindles can also be evenly spaced apart.

[0054] The spindle engaging mechanisms and the sub-spindle engaging mechanisms can be a spring-lock mechanism, a mechanical interface, a magnetic mechanism, or a combination thereof. Such spindle engaging mechanisms and sub-spindle engaging mechanisms permit the easy placement and removal of a particular sub-spindle, separate and independent of any other sub-spindle of the multiple spindle cartridge.

[0055] Returning to FIG. 2, each spindle comprises two or more sub-spindles 30, where the two or more sub-spindles of a respective spindle 24 are in axial longitudinal alignment from the spindle engaging mechanism on the first side (e.g.., 20) to the corresponding opposite spindle engaging mechanism on the second side (e.g., 21). Each sub-spindle 30 is removably and operably connected to another sub-spindle(s) 30 of the respective spindle 24 through a support bar 32, wherein the support bar is parallel to the first side 14 and the second side 16 and has respective corresponding sub-spindle engaging mechanisms 34. 34’ on opposite sides. Accordingly, each of the sub-spindles is independently removeable from the multiple spindle cartridge.

[0056] FIGS. 3A and 3B are schematic diagrams of an embodiment of a spindle assembly 35 of the present teachings. FIG. 3 A is a perspective view of a spindle 24 including a support tube 36 and two end collars 38, 38’. Each end includes an engaging mechanism 37, usually a passive connector, to a spring lock mechanism or a mechanical interface, to connect or attach to the spindle engaging mechanisms on the first side or the second side or the sub-spindle engaging mechanisms of the support bar as appropriate for the sub-spindle’s position. The inside diameter surface of the support tube typically is slidably or removably in contact with the outside diameter surface of the spindle. The support tube can be or include stainless steel. A mandrel or mandrel component, which can be a heat shrinkable tube, a fugitive tube or a coating, is located on the spindle or support tube, when present. The first layer of ceramic-forming composition is applied to a mandrel component (not shown).

[0057] FIG. 3B is an exploded side view of a same sub-spindle assembly 35. As can be seen, the support tube 36 is slidably removeable from the spindle 24 when (end) annular collar 38 is removed at one end. The spindle assembly 35 also includes another (end) annular collar 38’, located at the opposite end of the spindle 24. That is, each sub-spindle can include an annular collar positioned near or at each end of the sub-spindle, where the inside diameter surface of the annular collar is in contact with the outside diameter surface of the sub-spindle. In certain embodiments, an annular collar 38’ can be attached or unrem ovably connected to the subspindle. Accordingly, the two annular collars of a respective sub-spindle can abut the support tube to maintain its position in use. Annular collars can abut the first side, second side and support bar and the support tube to maintain contact, directly or indirectly with the other spindles.

[0058] In some embodiments, the end caps or annular collars can include additional features (e.g., flange is currently depicted) that would permit for a mating interface with ancillary, upstream, or downstream equipment. A magnetic striker plate can also be attached to the end caps to allow for interfacing with equipment through magnetic connections.

[0059] The sub-spindles of a spindle can be interconnected in the interior of multiple spindle cartridge through a support bar. The support bar typically will have bores through it where the sub-spindle engaging mechanisms can reside. The bores usually are evenly spaced across the longitudinal length of the support bar. A bore can contain a connection tube, whose surfaces are in slidable contact with each other, which connection tube includes the necessary sub-spindle engaging mechanism(s) for connect of the sub-spindles. In some embodiments, the support bar can have a top portion and a bottom portion, for example, the top portion and the bottom portion being hinged at one end so when opened, the sub-spindles can be placed in the spindle engaging mechanisms in the bore. When closed, the top portion and the bottom portion can secure the connection tubes and / or spindle engaging mechanisms in place for operation.

[0060] For example, FIG. 4A depicts a U-shaped spindle end 37 that mechanically interfaces and engages with a post 39 partially across or across a connection tube 41 in a bore 43 through the support bar 32. Each end of the respective sub-spindle is engaged in the same fashion. Accordingly, when one sub-spindle spins, the other sub-spindle spins so that the entire spindle spins at the same rate with the connection tube spinning in its respective bore. The connection tube can be held in place by the top portion of the support bar 45 being in close fitting contact with the bottom portion of the support bar 47 thereby defining and forming the bores 43 through the support bar 32 in which the connection tube 41 is secured. Other configurations and spindle engaging mechanisms are contemplated.

[0061] For example, FIG. 4B schematically depicts a cross-sectional side view of an embodiment of a support bar 32 and the ends of two sub-spindles 37, 37’ of the present teachings engaged with sub-spindle engaging mechanisms 34, 34’ that are spring loaded mechanisms. Similar to the embodiment shown in FIG. 4A, when one sub-spindle rotates the other subspindle will rotate at the same rate. Similar to the embodiment depicted in FIG. 4A, the subspindle engaging mechanisms rotate in a bore through the support bar, optionally within a connection tube as necessary for the particular design and construction of the sub-spindle engaging mechanisms.

[0062] Alternatively or in combination, the sub-spindle engaging mechanism can include a magnetic mechanism. Accordingly, both ends of each sub-spindle are removably connected to a spindle or sub-spindle engaging mechanism such that each sub-spindle is independently removeable from the multiple spindle cartridge, for example, via a spring lock mechanism, mechanical interface and / or a magnetic mechanism. When disengaged from the multiple spindle cartridge, the annular collars 38, 38’ typically are removed too, i.e., the sub-spindle assembly is removed.

[0063] When placed into position in the spindle and sub-spindle engaging mechanisms, a spindle comprised of a plurality of sub-spindles can rotate together as if one spindle such that the plurality of sub-spindles rotate at the same rate for an even application of the ceramic-forming layer(s). The engaging mechanisms in the support bar interconnect or are one piece such that when one sub-spindle is rotated, the other sub-spindles making up that spindle are rotated.

[0064] In certain embodiments, the interior edge of the annular collars define the ends of the tubular ceramic structure created about the spindle or support tube, if present. That is, the interior edge towards the midpoint of the length of the sub-spindle creates a mask about the spindle or support tube. As shown in FIG. 5 A, the annular collars 38, 38’ define the edges of the ceramic-forming layer 44 applied to the support tube 36, which contains a coating (not shown) that is considered the mandrel component of the forming tubular ceramic structure.

[0065] In certain embodiments, the sub-spindle assembly can further comprise a second annular collar around each of the annular collars, wherein the second annular collar can elongate in the longitudinal direction across the spindle or support tube, if present, to create a mask for forming a smaller length ceramic-forming layer, for example, an electrolyte-forming layer, on an anodeforming layer or an interface-forming layer. In such a way, the final product will have exposed at each end the underlying layers of the tubular ceramic structure, avoiding further processing. As shown FIG. 5A, the internal edges of the second annular collars 40, 40’ are aligned with internal edges of the annular collars 38, 38’ for the first applied ceramic-forming layers 44. FIG. 5B depicts the elongated second annular collars 40”, 40’”, which on each end of the ceramicforming layers creates a mask that only permits a smaller length ceramic-forming layer 42 to be applied onto the previously applied ceramic-forming layer 44.

[0066] An alterative way of creating a mask for the application of ceramic-forming layers is an even edge projection towards the midpoint and over the top of the spindle that would be adjacent or below a printer head. That is, the multiple spindle cartridge can further comprise a masking device, where the masking device is adapted, for example, to move into a position to create a mask for forming a smaller length ceramic-forming layer on an anode forming layer or an interface-forming layer. In various embodiments, the masking device is a flat, rigid, straight edged solid structure with a straight edge perpendicular to the longitudinal axis of the subspindle it masks. FIG. 5C shows such an even edge projection such as flat tabs 46, 46’ at each end of the sub-spindle thereby creating the smaller length ceramic-forming layer 42’ on top of previously applied ceramic-forming layer(s) 44’. Often the smaller length ceramic-forming layer is an electrolyte-forming layer. The flat tabs can project out from the first side, second side and support bars when needed but can retract, partially or fully, to create other exposed layers, as desired. The second annular collars could do the same, i.e., to expose multiple underlying layers. These masking devices can be attached via various mechanisms, e.g., magnetically or with a mechanical interface.

[0067] The masking device can be a triangular shape, for example, magnetically attached or clipped onto the annular collar, that rotates with the spindle thereby forming a smaller length ceramic forming layer having a triangular section at the end of the spindle that does not include the applied layer(s) when the masking device is in place. FIG. 5D shows such a triangular masking device 46” that rotates with the spindle thereby forming a triangular section devoid of ceramic-forming layers when the masking device is in place and forming an end of the tube that schematically looks like that in FIG. 5E. In FIG. 5E, the first applied ceramic-forming layers 44” are shown along with the pattern of the smaller length ceramic-forming layer 42”. Different shaped masks can be used to provide different shaped void areas or areas devoid of additional ceramic-forming layers applied when the mask is in place.

[0068] Features can be added to the sub-spindle assembly end caps or annular collars (e.g., a groove or pin hole) that can permit the clocking of the masking device as described in FIG. 5E. Clocking describes the radial position of the masking device on one end cap across the spindle relative to the other end cap. In this case, clocking would describe the radial position between end cap 38 and 38’.

[0069] FIGS. 6 A and 6B depict an alternative way to control the diameter of the ceramicforming layers during their application. Below the spindle assembly 35 and in particular, support tube 36, is a scrapper or blade 51 that can be used to control the thickness or diameter of the ceramic-forming layer as it is applied to the support tube or other ceramic-forming layer as the green body is created. In practice, as the ceramic-forming layer is applied, it increases in diameter, causing it to interfere with the scrapper or blade. The scrapper or blade will scrap or remove any excess ceramic-forming layer from the supporting tube, creating a even and uniform layer.

[0070] FIG. 6A also depicts adjustment screws 53, 53’ on both ends of the scrapper or blade 51, which allows for vertical adjustment of the scrapper or blade in relation to the supporting tube and growing ceramic-forming layers. The vertical adjustment can allow for tuning and adjustment of the final diameter of a particular layer and / or end product.

[0071] FIG. 6B is a cross-sectional schematic along line 6B-6B of the support tube of the subspindle assembly with the scrapper or blade of FIG. 6 A. The cross-sectional view illustrates that the scrapper or blade is centered under the support tube. FIG. 6B also shows a embodiment of the scrapper or blade 51 that has a radius feature at the tip that would conform to the desired end diameter of the applied ceramic-forming layer. Embodiments of this component would allow for a fine point or be more represented as a blade, cutting material off the tube as material is applied.

[0072] In various embodiments, the plurality of spindles of a multiple spindle cartridge can include two spindles, three spindles, four spindles, five spindles, six spindles, seven spindles, eight spindles, nine spindles, ten spindles, eleven spindles, twelve spindles, thirteen spindles, fourteen spindles, fifteen spindles, sixteen spindles, seventeen spindles, eighteen spindles, nineteen spindles, twenty spindles, twenty-one spindles, twenty-two spindles, twenty-three spindles, twenty-four spindles, or more spindles. In some embodiments, each spindle includes two sub-spindles, three sub-spindles, four sub-spindles, five sub-spindles, six sub-spindles, or more.

[0073] The multiple spindle cartridge of the present teachings can also include a rotation mechanism or rotation mechanisms in direct or indirect contact with the spindle engaging mechanisms on the first side of the frame, wherein the rotation mechanism(s) is adapted to rotate the plurality of spindles. The rotation mechanism(s) can rotate each spindle individually or can rotate the plurality of spindles as a unit or sub-unit. To that end, the rotation mechanism(s) typically is adapted to rotate the plurality of spindles at the same speed for even application of the ceramic-forming layers on the rotating spindles. The rotation mechanism can be individual motors and gears and / or rotating belts for each spindle. More practical is a rotation mechanism that is an elliptical belt, or gears, or a combination thereof that are interconnected to move each of the spindles at the same time and at the same rate. The drive belt, or gears, or combination thereof can be configured to rotate the plurality of spindles in the same direction or in alternating directions, or any combination of both. For example, returning to FIG. 2, a rotation mechanism 49 is depicted where a main gear or cog 48 is present that when rotated, a series of gears or cogs 50, each attached directly or indirectly to a respective spindle, is rotated such that all the spindles can rotate at the same speed. Of course other designs are contemplated, for example, to move the spindles independently such as to rotate them in different directions and / or at different rotational rates.

[0074] The multiple spindle cartridge can include a controller C, which includes computer software and hardware to automate the rotation of the spindles at a pre-determined rate. That is, the controller can control the rotation of the main gear or cog to rotate each of the spindles. The rate of rotation can be between about 50 rpm to about 300 rpm. In another aspect, the present teachings provide a system for making tubular structures such as tubular ceramic structures, where the system includes a multiple spindle cartridge as described herein; and a printer assembly comprising a printer head positioned above a spindle or support tube, if present, wherein the printer head is adapted to move linearly along the longitudinal axis of the spindle from the first side to the second side of the frame, from the second side to the first side of the frame, and perpendicularly.

[0075] In particular embodiments, the printer assembly comprises two printer heads, spaced apart at a distance equal to the distance between one spindle and another spindle, for example, a first spindle and a second spindle. The printer assembly is moveable linearly and perpendicularly, and usually diagonally, along the longitudinal axis of the plurality of spindles. For example, as seen in FIG. 7, a multiple spindle cartridge 10 includes a first printer head 58 and a second printer head 58’, spaced apart as described above. The system can also include a ceramic-forming composition reservoir 52, 52’ associated with each printer head 8, 8’, respectively. The ceramic-forming composition reservoir contains the ceramic-forming composition materials that form the appropriate ceramic-forming layer that is to be applied.

[0076] With reference to the first printer head 8 which movement is equally applicable to the second printer head 8’, the first printer head can move linearly along the longitudinal axis of the spindle from the first side 14 to the second side 16 of the frame along the direction indicated by the arrow headed line P (structure for facilitating such movement as described herein not shown for simplicity). The printer head is also adapted to move linearly along the longitudinal axis of the spindle from the second side 16 to the first side 14 of the frame as indicated by the double headed arrow labeled P. In some embodiments, the printer head is adapted to move linearly, perpendicularly (e.g., along the line with the double headed arrow labeled P’), and diagonally (e.g., along the line with the double headed arrow labeled P”) along the longitudinal axis of the plurality of spindles from the first side 14 to the second side 16 of the frame and from the second side 16 to the first side 14 of the frame. The diagonal movement along line P” can be at a lesser angle than that as shown in FIG. 7 such that it is vertical direction is the width of a sub-spindle 30. With the ability to move in all directions, the printer heads can print patterned layers such as a serpentine pattern.

[0077] As a printer head moves longitudinally along a spindle, the application of a ceramicforming layer can be stopped when passing over a support bar(s) or can continue to be applied with the support bars cleaned off at the appropriate intervals, where the ceramic-forming composition can be recycled. A multiple spindle cartridge and associated systems can also include a controller, which contains computer software program(s) and appropriate hardware for automating the operation of the multiple spindle cartridge and associated components and systems. Returning to FIG. 7, the controller C” is in communication with the rotation mechanism 48 and each of printer heads 58, 58’, either individually or through one or the other. The controller can monitor and adjust the parameters of the multiple spindle cartridge and / or system such as the rotation of the spindles / sub-spindles, the rate of rotation, the application of ceramic-forming layers, the composition of the ceramic-forming layers, and coordinate the movement of the printer head(s). The controller can also operate a camera for inspecting the forming tubular ceramic green bodies as well as inspection of the images of the camera for defects in the forming tubular ceramic green bodies, and can record the results of the inspections with identifying and related information.

[0078] In another aspect, the present teachings provide methods of making tubular structures such as tubular ceramic structures, for example, tubular ceramic green bodies that are fired to create tubular SOFCs. In various embodiments, a method of using a multiple spindle cartridge as described herein to produce a tubular ceramic green body generally comprises rotating the plurality of spindles of a multiple spindle cartridge; and applying an ceramic-forming layer to the sub-spindles of the plurality of spindles or on an already applied layer on the sub-spindles of the multiple spindle cartridge.

[0079] The application of the layers is usually accomplished by printing or spraying such as by ultrasonic spraying of the ceramic-forming layer using a printer head.

[0080] The composition of the anode-forming layer can be varied as the layer is applied. For example, the ceramic composition can be varied by elemental composition (e.g., amount of ceramics, metal oxides and / or precious metals) or can be a completely different composition such an inert layer (it should be understood that the anode-forming layer can be considered to be made up of many different layers, each layer being a different composition). An inert layer can be useful to increase the thermal shock of the tubular SOFCs and / or for absorbing or filtering contaminants. An active catalyst layer can also serve this latter purpose, i.e., for absorbing, chemically modifying, and / or filtering contaminants.

[0081] In some embodiments, the methods include inspecting each of the anode-forming layer, the interface-forming layer, and the electrolyte-forming layer, and optionally, the insert-forming layer and / or the active catalyst-forming layer; and removing from the multiple spindle cartridge any sub-spindle comprising a tubular ceramic green body which is identified as having a defect or out of specification during the inspection.

[0082] In various embodiments, the methods include inspecting visually. In some embodiments, inspecting visually comprises inspecting visually using a camera. In certain embodiments, inspecting visually using a camera comprises using a computer software program to identify a defect based on an image from the camera. In particular embodiments, inspecting visually comprises maintaining a record such as recording information of the inspection of a particular sub-spindle of the cartridge. The recorded information can also include information of a layer as it is being applied.

[0083] In particular embodiments, the present teachings provide a method for producing tubular ceramic green bodies including: providing a multiple spindle cartridge as described herein, wherein the cartridge is adapted to rotate the plurality of spindles usually at the same rate and wherein each of the subspindles comprises a mandrel component; rotating the plurality of spindles and applying an anode-forming layer to each of the respective mandrels of the plurality of rotating spindles of the multiple spindle cartridge to form a plurality of anode-forming green bodies about each respective spindle; inspecting each of the plurality of anode-forming green bodies for defects or properties out of specification; rotating the plurality of anode-forming green bodies and applying an interface-forming layer to each of the respective anode-forming green bodies of the plurality of rotating anodeforming green bodies of the multiple spindle cartridge to form a plurality of multiple layered green bodies about each respective spindle; inspecting each of the plurality multiple layered green bodies for defects or properties out of specification; rotating the plurality of multiple layered green bodies and applying an electrolyteforming layer to each of the respective multiple layered green bodies of the plurality of rotating multiple layered green bodies of the multiple spindle cartridge to form a plurality of tubular ceramic green bodies about each respective spindle; inspecting each of the plurality of tubular ceramic green bodies for defects or properties out of specification; and removing any sub-spindle assemblies comprising a tubular ceramic green body which was identified as having a defect or property out of specification during the inspections, prior to firing the tubular ceramic green body. In various embodiments, the methods include removing the tubular ceramic green bodies from the spindles; and sintering the tubular ceramic green bodies. One or more further production operations can be performed on the tubular ceramic green bodies such as the formation thereon of one or more additional layers, for example, interlayer thin film(s) or a cathode layer, can occur either before or after sintering to burning out any organics and other materials assisting in the formation of a solid tubular ceramic structure such as a tubular ceramic green body.

[0084] INCORPORATION BY REFERENCE

[0085] The entire disclosure of each of the patent documents and scientific articles referred to herein is incorporated by reference for all purposes.

[0086] EQUIVALENTS

[0087] The disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting the disclosure described herein. Scope of the disclosure is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein..

[0088] What is claimed is:

Claims

CLAIMS1. A multiple spindle cartridge for making tubular ceramic structures comprising: a frame comprising a first side and a second side, wherein the first side of the frame is parallel to the second side of the frame secured by a support structure between the first side and the second side; wherein the first side of the frame comprises a series of spindle engaging mechanisms and the second side of the frame comprises a series of corresponding spindle engaging mechanisms opposite the series of spindle engaging mechanisms along the first side of the frame; and a plurality of spindles, being parallel to and in the same plane as each other, wherein one end of each of which is engaged in the spindle engaging mechanism on the first side of the frame and the other end of each of which is engaged in the respective corresponding opposite spindle engaging mechanism on the second side of the frame, wherein each spindle comprises two or more sub-spindles, the two or more subspindles of a respective spindle being in axial longitudinal alignment from the spindle engaging mechanism on the first side to the corresponding opposite spindle engaging mechanism on the second side, wherein each sub-spindle is removably and operably connected to another sub-spindle(s) of the respective spindle through a support bar, wherein the support bar is parallel to the first side and the second side and has respective corresponding sub-spindle engaging mechanisms on opposite sides; wherein each of the sub-spindles is independently removeable from the multiple spindle cartridge.

2. The multiple spindle cartridge of claim 1, wherein each of the plurality of spindles comprises a support tube, wherein the inside diameter surface of the support tube is slidably in contact with the outside diameter surface of the spindle.

3. The multiple spindle cartridge of claim 2, wherein the support tube comprises stainless steel.

4. The multiple spindle cartridge of any one of claims 1-3, wherein each of the two or more sub-spindles comprises an annular collar positioned near or at each end, wherein the inside diameter surface of the annular collar is in contact with the outside diameter surface of the spindle.

5. The multiple spindle cartridge of claim 4, wherein one of the annular collars is attached to the spindle.

6. The multiple spindle cartridge of any one of claims 1-5, wherein the spindles and subspindles are engaged with the respective spindle and sub-spindle engaging mechanisms via a magnetic mechanism, a mechanical interface, a spring lock mechanism, or a combination thereof.

7. The multiple spindle cartridge of any one of claims 1-6, wherein each of the sub-spindles is independently removeable via a spring lock mechanism.

8. The multiple spindle cartridge of any one of claims 4-7, wherein the annular collars of a respective sub-spindle abut the support tube to maintain its position in use.

9. The multiple spindle cartridge of any one of claims 4-8, wherein the annular collars disengage from the multiple spindle cartridge along with the sub-spindle and support tube, if present.

10. The multiple spindle cartridge of any one of claims 4-9, wherein the interior edge of the annular collars define the ends of a tubular ceramic structure created about the spindle or support tube, if present.

11. The multiple spindle cartridge of any one of claims 4-10, further comprising a second annular collar around each of the annular collars, wherein the second annular collar can elongate in the longitudinal direction across the spindle or support tube, if present, to create a mask for forming a smaller length ceramic-forming layer on an anode-forming layer or an interfaceforming layer.

12. The multiple spindle cartridge of any one of claims 1-11, further comprising a masking device, wherein the masking device is adapted to create a mask for forming a smaller length ceramic-forming layer on an anode forming layer or an interface-forming layer.

13. The multiple spindle cartridge of claim 12, wherein the masking device is a flat, straight edged solid structure with the straight edge perpendicular to the longitudinal axis of the subspindle it masks thereby forming a smaller length ceramic forming layer.

14. The multiple spindle cartridge of claim 12, wherein the masking device is a triangular shape that rotates with the spindle thereby forming a smaller length ceramic forming layerhaving a triangular section at the end of the spindle that does not include the applied layer(s) when the masking device is in place.

15. The multiple spindle cartridge of any one of claims 11-14, wherein the smaller length ceramic-forming layer is an electrolyte-forming layer.

16. The multiple spindle cartridge of any one of claims 1-15, wherein each spindle comprises two sub-spindles, three sub-spindles, or four sub-spindles.

17. The multiple spindle cartridge of any one of claims 1-16, wherein the plurality of spindles comprises four spindles, eight spindles, twelve spindles, sixteen spindles, twenty spindles, or twenty-four spindles.

18. The multiple spindle cartridge of any one of claims 1-17, comprising a rotation mechanism in direct or indirect contact with the spindle engaging mechanisms on the first side of the frame, wherein the rotation mechanism is adapted to rotate the plurality of spindles.

19. The multiple spindle cartridge of any one of claims 1-18, comprising a rotation mechanism in direct or indirect contact with the spindle engaging mechanisms on the first side of the frame, wherein the rotation mechanism is adapted to rotate the plurality of spindles at the same speed.

20. The multiple spindle cartridge of claim 18 or 19, wherein the rotation mechanism comprises an elliptical belt, gears, or a combination thereof.

21. The multiple spindle cartridge of claim 1-20, wherein the rotation of the plurality of spindles can occur in the same direction, opposite directions, or a combination thereof among adjacent spindles.

22. The multiple spindle cartridge of any one of claims 1-21, wherein the spindles are evenly spaced apart.

23. The multiple spindle cartridge of any one of claims 1-22, comprising a controller, wherein the controller comprises computer software and hardware to automate the rotation of the spindles at a pre-determined rate.

24. The multiple spindle cartridge of any one of claims 1-23, comprising a scrapper or blade positioned adjacent to and at a pre-determined distance from the support tube of the sub-spindle assembly thereby to control the thickness of an applied ceramic-forming layer.

25. A system for making tubular ceramic structures, the system comprising a multiple spindle cartridge of any one of claims 1-24; and a printer assembly comprising a printer head positioned above a spindle or support tube, if present, wherein the printer head is adapted to move linearly along the longitudinal axis of the spindle from the first side to the second side of the frame.

26. The system of claim 25, wherein the printer head is adapted to move linearly along the longitudinal axis of the spindle from the second side to the first side of the frame.

27. The system of claim 25 or 26, wherein the printer head is adapted to move linearly, perpendicularly, and diagonally along the longitudinal axis of the plurality of spindles from the first side to the second side of the frame and from the second side to the first side of the frame.

28. The system of any one of claims 25-27, wherein the printer assembly comprises two printer heads, spaced apart at a distance equal to the distance between a first spindle and a second spindle, and is moveable linearly, perpendicularly, and diagonally along the longitudinal axis of the plurality of spindles.

29. The system of any one of claims 25-28, comprising a ceramic-forming composition reservoir to supply the printer head(s) with ceramic forming composition.

30. The system of any one of claims 25-29, comprising a controller, wherein the controller comprises computer software and hardware to automate the rotation of the spindles at a predetermined rate, to coordinate the application of the ceramic-forming layers through the printer spray head(s), to coordinate the composition of the ceramic-forming layers, and to coordinate movement of the printer spray head(s).

31. A method of using a spindle cartridge of any one of claims 1-24 or the system of any one of claims 25-30 to produce a tubular ceramic green body, the method comprising: rotating the plurality of spindles, each comprising sub-spindles comprising a mandrel; and apply a ceramic-forming layer to the mandrels of the sub-spindles or on an already applied layer on the sub-spindles of the multiple spindle cartridge.

32. The method of claim 31 wherein applying a ceramic-forming layer comprises applying an anode-forming layer, an interface-forming layer, an electrolyte-forming layer, an inertforming layer and / or an active catalyst-forming layer to the sub-spindles or on an already applied layer on the sub-spindles of the multiple spindle cartridge.

33. The method of claim 32, comprising inspecting each of the anode-forming layer, the interface-forming layer, and the electrolyte-forming layer, and optionally, the insert-forming layer and / or the active catalyst-forming layer; and removing from the multiple spindle cartridge any sub-spindle comprising a tubular ceramic green body which is identified as having a defect or property out of specification during an inspection.

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