US20120017439A1

US20120017439A1 - Method of fabricating a reaction chamber for a fuel storage assembly

Info

Publication number: US20120017439A1
Application number: US13/191,360
Authority: US
Inventors: Kei Edgardo Yamamoto; Courtney Aline Helland; Matthieu JONEMANN; Andrew Peterson; Daniel Braithwaite
Original assignee: Individual
Current assignee: Ardica Technologies Inc
Priority date: 2010-07-26
Filing date: 2011-07-26
Publication date: 2012-01-26
Also published as: WO2012018640A1

Abstract

A method for manufacturing a reaction chamber comprising a fuel insert and an elastic enclosure with a body and an opening, the method including the steps of stretching the body of the elastic enclosure to define a working lumen, orienting the metal hydride insert within the working lumen, and restituting the elastic enclosure over the insert.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/400,412, filed 26 Jul. 2010, which is incorporated in its entirety by this reference.

TECHNICAL FIELD

This invention relates generally to the reaction chamber field, and more specifically to a new and useful method of manufacturing a reaction chamber in the reaction chamber field.

BACKGROUND

In fuel generation systems, stable and repeatable performance for both continuous and on/off operation are highly desirable. Stable fuel generation from fuel carriers relies on how well a uniform and constant reaction interface is maintained between a fuel carrier and liquid reactant. In conventional systems, this reaction control is achieved by utilizing a liquid fuel carrier and pumping a designated amount of the fuel carrier to catalysts. However, solution type fuel carriers are less favored due to their low energy density. While solid fuel carriers have higher energy densities than liquid solutions, their further development has been hampered by difficulty in achieving reliable reaction control. The reaction control of a solid fuel carrier system relies on both the pumping rate of liquid reactants and the size of a reaction interface. In practical cases, volatile hydrolysis reaction at the interface leaves cavities or voids when the generated products flow away from the interface. This results in a non-contact between a fuel surface and liquid delivery medium such as a nozzle or wick. When this occurs, the performance of hydrogen generation system degrades over time. Furthermore, the performance of the fuel system becomes unpredictable when it is restarted after a stop period from the previous run. Typically, when the fuel system is investigated after its operation for a certain period, large gaps or voids are observed between the non-reacted surface of the solid fuel and the liquid delivery mechanism (LDM) such as a nozzle, wick, or membrane. This lack of control in maintaining constant and intact boundary between a solid fuel and liquid delivery medium has been the largest obstacle to achieving reliable performance of a solid fuel system.
Thus, there is a need in the fuel generator field to create a new and useful reaction chamber. This invention provides such new and useful reaction chamber.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of a method of manufacturing a reaction chamber.

FIGS. 2A, 2B, and 2C are schematic representations of a first, second, and third step, respectively, of a vacuum embodiment of the step of stretching the body of the elastic enclosure to define a working lumen.

FIGS. 3A, 3B, and 3C are schematic representations of a first, second, and third step, respectively, of a first embodiment of the second step of the vacuum embodiment.

FIG. 4 is a schematic representation of a second embodiment of the second step of the vacuum embodiment.

FIG. 5 is a schematic representation of a variation of the second embodiment of the second step of the vacuum embodiment.

FIG. 6 is a schematic representation of a positive pressure embodiment of the step of stretching the body of the elastic enclosure to define a working lumen.

FIG. 7 is a schematic representation of an embodiment of the step of orienting the fuel insert within the working lumen.

FIGS. 8A and 8B are schematic representations of a first and second embodiment, respectively, of the step of inserting a liquid delivery mechanism into the reaction chamber.

FIG. 9 is a schematic representation of a first method of sealing the elastic enclosure opening about the liquid delivery mechanism.

FIG. 10 is a schematic representation of a first method of trimming a portion of elastic enclosure from the reaction chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the invention is not intended to limit the invention to these preferred embodiments, but rather to enable any person skilled in the art to make and use this invention.
The method for manufacturing a reaction chamber comprises the steps of stretching the body of an elastic enclosure to define a working lumen S200; orienting a fuel insert within the working lumen S300; and, restituting the elastic enclosure over the insert S400. This method preferably utilizes an elastic enclosure and a fuel insert. The method preferably produces a reaction chamber with the elastic enclosure disposed substantially around the fuel insert, such that the elastic enclosure is in tension about the insert and applies a compressive force to the insert. The reaction chamber is preferably used to contain and control a fuel-generating reaction, more preferably a hydrogen-generating reaction. In operation, the elastic enclosure maintains contact between a liquid reagent delivery mechanism and a reaction zone, wherein the reaction zone is preferably the surface of the unreacted fuel insert. To address the issues described above, the reaction chamber of the preferred embodiments provides a moving boundary interface (i.e. the elastic enclosure) that ensures constant contact between a solid fuel insert and the liquid delivery mechanism and/or the liquid reagent by bringing the liquid delivery mechanism and/or the liquid reagent in contact with the varying contour of the reacting surface of the fuel insert. When the fuel insert is consumed and decreases in volume, the elastic enclosure shrinks and maintains substantially continuous contact with the insert surface. The assembled reaction chamber is preferably substantially similar to the reaction chamber disclosed in U.S. application Ser. No. 12/460,794, filed Jul. 23, 2009, incorporated herein by this reference. However, the assembled reaction chamber may be any suitable elastic reaction chamber that may facilitate volume exchange with the reaction products and/or collector. The method is preferably automated and performed by machinery using one or more machines, but may alternately be performed by hand, utilizing one or more assembly personnel.
The elastic enclosure 100 of the reaction chamber functions to apply a compressive force about substantially the whole of the fuel insert. As shown in FIG. 1, the elastic enclosure preferably comprises a substantially continuous body 140 that defines a lumen, and an opening portion 120 that defines the elastic enclosure opening. The elastic enclosure preferably takes little to no deformation set, restituting to the original dimensions after long periods in a stretched position. Adequate restitution ability is desirable to allow substantially complete consumption of the fuel insert; without adequate restitution ability, the elastic enclosure eventually loses continuous contact with the fuel insert during operation, which may result in uncontrolled and incomplete reaction of the fuel insert. The elastic enclosure preferably restitutes completely to its original dimensions after stretching, but may restitute to a size slightly larger or substantially larger than its original dimensions. In the end product, the elastic enclosure preferably includes a first and a second outlet defining an LDM inlet and a reaction product outlet, respectively, wherein the LDM inlet and reaction product outlet are preferably disposed near opposing ends of the fuel insert, but may alternatively be on the same end and be defined by the same elastic enclosure opening. The elastic enclosure is preferably a formed membrane, more preferably a tube with a first and a second opening. The tube diameter is preferably substantially constant throughout the tube length, but may vary (e.g. one opening has a larger diameter than the body, the body has a larger diameter that the openings, etc.). The tube diameter is preferably smaller than the diameter and/or width of the fuel insert at any given point. The tube length is preferably sized to encapsulate the entire length of the insert, but may alternatively be longer or shorter than the insert. The tube is preferably cut to length before assembly, but may alternately be cut to length during assembly. The elastic enclosure may alternatively have any suitable shape or form. The elastic enclosure preferably comprises material that is inert, but may comprise material that resists degradation and/or reaction with the fuel insert material, liquid reagent, and reaction products. The elastic enclosure is preferably made from silicone, latex, or any suitable elastomeric material, and may be additionally reinforced (e.g. with a metal layer, other polymeric materials, etc). In one preferred embodiment, the elastic enclosure is made from platinum-cured silicone tubing such as SANI-TECH item number STHT-C-312-1F with a tensile strength of approximately 8.57 MPa and a tensile modulus of approximately 2.13 MPa. The elastic enclosure is preferably extruded, but may alternately be formed, injection molded, dipped, or made using any suitable manufacturing method.
The fuel insert 200 functions to store fuel and to provide a reaction interface. This reaction interface is preferably along the surface of the fuel insert, and is preferably constantly changing as the insert is consumed by the reaction. The fuel insert preferably forms fuel upon reaction with a liquid reagent, and preferably forms hydrogen gas but may alternatively form any suitable fuel (e.g. methane, butane, etc.). The fuel insert preferably comprises a metal hydride fuel carrier, more preferably sodium borohydride (SBH) fuel carrier, but may alternately include lithium borohydride, alane, or any other suitable fuel carrier. The fuel insert preferably comprises metal hydride powder compressed into a solid insert (e.g. pill), but may alternately comprise a solid block of metal hydride. The fuel insert may alternatively be manufactured by injection molding, sintering, or any other suitable method of manufacturing a fuel insert. The fuel insert preferably includes guide grooves, preferably a liquid delivery mechanism (LDM) guide groove and/or an alignment groove. The LDM guide groove functions to allow easy insertion and alignment of the LDM with the insert. The alignment groove functions to align the fuel insert with other fuel inserts, the elastic enclosure and/or other components encapsulated within the elastic enclosure in the end product (e.g. exhaust nozzles, filters, etc.). The guide grooves are preferably located on the exterior of the fuel insert, but may alternately be located on the interior. However, the fuel insert may alternately include other grooves or not include any grooves at all. The fuel insert may additionally include any suitable alignment features. The reaction chamber preferably includes one fuel insert, but may additionally include any number of fuel inserts of any composition.
The reaction chamber may additionally include a liquid delivery mechanism (LDM) 220 that functions to deliver a liquid reagent to the reaction zone. The reaction zone is preferably the surface of the fuel insert, but may alternatively be on the interior of the fuel insert. The LDM is preferably a flexible tube, but may alternatively comprise a nozzle, multiple tubes of different lengths, multiple tubes of the same length, multiple nozzles of different varieties, a combination of the above, or any other suitable liquid delivery mechanism. The LDM is preferably the longer than the length of the fuel insert such that it covers the entirety of the fuel insert, but may alternately cover only a portion of the fuel insert, or be substantially shorter than the fuel insert. However, the LDM may be any suitable configuration to deliver liquid reagent to the reaction zone. The LDM is preferably substantially solid such that it does not leak, but may alternatively have holes or be porous along a section (e.g. the section proximal to the insert after assembly or the whole length). The LDM is preferably flexible, but may be substantially rigid. The LDM is preferably impervious to the liquid reagent, and preferably comprises ultra-high molecular weight polyethylene (UHMWPE), high-density polyethylene (HDPE), polypropylene, PTFE, PVDF, or any other suitable material. The LDM may additionally include a distribution mechanism, such as wicking materials leading from the lumen of the LDM to the exterior to facilitate liquid reagent distribution, pores along the fuel insert-contacting length, side channels, or any other suitable distribution mechanism. The reaction chamber preferably includes one LDM, but may alternatively include a plurality of LDMs of the same or of varying lengths.
The step of stretching the body of the elastic enclosure to define a working lumen S200 functions to achieve an elastic enclosure configuration that allows for easy fuel insert insertion. The working lumen 160 is preferably formed from the elastic enclosure body interior, wherein the elastic enclosure body is stretched to a diameter and length that readily accepts the desired portion of the fuel insert (e.g. stretched to achieve dimensions larger than the fuel insert, stretched to a larger diameter than the insert, stretched to a longer length than the insert length or width, etc). S200 may additionally include the step of halting and maintaining the working lumen configuration, wherein the stretching force is adjusted and/or maintained to retain the desired working lumen configuration.
In a first embodiment (“vacuum embodiment”) of S200, the working lumen is achieved by pulling suction on the exterior of the elastic enclosure, and preferably uses a vacuum tube 300 coupled to a vacuum generator (suction generator), wherein the vacuum tube includes an opening through which the elastic enclosure is received into the vacuum tube lumen. The vacuum tube is preferably substantially sealed except for the vacuum tube opening, and preferably has a substantially constant diameter throughout its length but may alternately have a variable diameter. As shown in FIG. 2, this embodiment preferably comprises the steps of placing the elastic enclosure body within the vacuum tube, wherein the elastic enclosure opening is left external the vacuum tube (S220); securing the elastic enclosure opening to the vacuum tube, wherein securing the elastic enclosure opening seals the vacuum tube opening about the elastic enclosure body (S230); and pulling suction within the vacuum tube to expand the elastic enclosure body (S240). The step of placing the elastic enclosure body within the vacuum tube (S220) is preferably accomplished by orienting the elastic enclosure body within the vacuum tube lumen, wherein the elastic enclosure opening is left outside the vacuum tube, as shown in FIG. 2A. The elastic enclosure is preferably inserted into the vacuum tube from the top or the side, but the vacuum tube may be inverted over the elastic enclosure. In this step, the elastic enclosure body is preferably sealed (i.e. the elastic enclosure opening is the only opening to the elastic enclosure lumen) prior to placement in the vacuum tube, but may alternately be sealed after placement. The elastic enclosure body is preferably sealed by a knot, but may be sealed by clips, welding, adhering the opening edges together, or any other suitable method. This step is preferably used when the elastic enclosure has more than one opening, for example, when the elastic enclosure is a tube. Alternatively, the elastic enclosure may be manufactured to have only one opening, wherein the step of elastic enclosure sealing is unnecessary. The vacuum tube lumen is preferably lubricated prior to elastic enclosure placement, and is preferably lubricated with a non-reactive powder (e.g. baby powder, corn starch, talc, etc.), but may alternately be lubricated with a liquid.
As shown in FIG. 2B, the step of securing the elastic enclosure opening to the vacuum tube and sealing the vacuum tube opening about the elastic enclosure body S230 functions to seal the vacuum tube such that it can pull a vacuum, and to prevent the elastic enclosure from shifting while it is being stretched to create the working lumen. This step S230 preferably results in the opening portion of the elastic enclosure (e.g. the portion of the elastic enclosure near the opening) folded over the vacuum tube opening, with the elastic enclosure body enclosed within the vacuum tube lumen, and the elastic enclosure opening wrapped about the vacuum tube exterior. Step S230 may be accomplished using several different embodiments. Throughout these embodiments, the adhesive properties (e.g. tackiness) of the elastic enclosure material and the elasticity of the elastic enclosure (e.g. the restitution force) preferably secure the elastic enclosure position relative to the vacuum tube, but the elastic enclosure may be secured to the vacuum tube by mechanical means (e.g. clips, clamps, washers), by chemical means, or by any other suitable means. In a first embodiment of S230 (“tube stretching apparatus” embodiment), the elastic enclosure is pre-folded S231 then transferred to the vacuum tube S233. In this embodiment, the elastic enclosure pre-folding occurs prior to the step of placing the elastic enclosure within a vacuum tube, and the step of transferring the folded elastic enclosure seals and secures the elastic enclosure to the vacuum tube opening. As shown in FIG. 3, the step of pre-folding the elastic enclosure is preferably accomplished by folding the elastic enclosure opening over the radially contracted fingers of a enclosure-stretching apparatus S231 and radially stretching the folded portion of the elastic enclosure incrementally until a working diameter (e.g. a diameter that can fit over the vacuum tube opening, preferably a diameter larger than the vacuum tube opening) is reached S232. As shown in FIG. 3A, the step of folding the elastic enclosure opening over the fingers of an enclosure-stretching apparatus S231 preferably includes the sub-steps of installing the substantially unstretched elastic enclosure between the fingers of the enclosure-stretching apparatus, such that the fingers hold the body of the elastic enclosure and the opening portion (portion to be folded over the vacuum tube) is left free from the fingers (S231 a); and stretching the opening portion over the fingers, such that the fingers are disposed between the opening portion and the elastic enclosure body (S231 b). As shown in FIG. 3B, the step of radially stretching the folded portion of the elastic enclosure incrementally to achieve a working diameter S232 is preferably accomplished by incrementally moving opposing pairs of fingers away from each other (e.g. by turning knobs or levers that control the radial position of each finger), but may alternately be accomplished by moving any combination of the fingers away from each other to achieve a substantially circular configuration. However, the step of pre-folding the elastic enclosure may be accomplished using any other suitable method. As shown in FIG. 3C, the step of transferring the folded elastic enclosure to the vacuum tube S233 preferably comprises the steps of orienting the vacuum tube opening within the fold (i.e. between the elastic enclosure body and opening portion) (S233 a), and advancing the vacuum tube towards the fold, pushing the folded elastic enclosure off the enclosure-stretching apparatus and onto the vacuum tube opening (S233 b). S233 is preferably accomplished by placing the vacuum tube underneath the elastic enclosure within the tube stretching apparatus, such that the elastic enclosure body hangs down into the vacuum tube lumen, then pushing the vacuum tube up, into the fold, until the elastic enclosure is transferred onto the vacuum tube and is completely free of the tube stretching apparatus. Alternatively, the step of transferring the folded elastic enclosure to the vacuum tube S233 may include the steps of placing the vacuum tube opening inside the elastic enclosure lumen (such that the vacuum tube is inverted), sliding the elastic enclosure opening portion off the tube stretching apparatus fingers onto the vacuum tube, and inverting the elastic enclosure body into the vacuum tube lumen. However, the folded elastic enclosure may be transferred onto the vacuum tube in any suitable orientation (e.g. sideways, etc) utilizing any suitable method. The first embodiment of S230 may additionally include the sub-step of pre-stretching the elastic enclosure prior to installation in the tube stretching apparatus, wherein pre-stretching conditions the elastic enclosure to a desired elasticity. Pre-stretching the elastic enclosure preferably includes pressurizing the elastic enclosure such that the elastic enclosure opening undergoes a slight plastic deformation to allow for easier folding over the fingers, but may alternately utilize any suitable pre-stretching method. In a second embodiment of S230 (“flared opening” embodiment), as shown in FIG. 4, the elastic enclosure has a flared opening that is created and/or folded over the vacuum tube opening. The flared opening is preferably the opening portion of the elastic enclosure (to be folded over the vacuum tube), and preferably flares to a larger diameter from the elastic enclosure body, wherein the larger diameter is preferably the working diameter (e.g. substantially close to or larger than the vacuum tube diameter), such that minimal additional stretching is required to fold the flared opening over the vacuum tube opening. As shown in FIG. 5, the elastic enclosure may be manufactured with an opening smaller than the working diameter, wherein a flared opening is created. The flared opening is preferably created by placing the sealed elastic enclosure body within the vacuum tube lumen, while leaving the opening portion outside the vacuum tube S210; coupling the elastic enclosure opening to a positive pressure source (e.g. compressed air, compressed air generator, etc.) S235; pressurizing the elastic enclosure such that a flare with a larger diameter than the vacuum tube opening is created in the opening portion S236; and temporarily sealing off the elastic enclosure opening when a working diameter is reached to maintain internal pressure (e.g. by pinching, clamping, etc.) S236 a. Elastic enclosure securing and sealing of to the vacuum tube opening S230 is then accomplished by sliding the flared opening over the vacuum tube exterior while slowly releasing the internal pressure. Any excess elastic enclosure near the vacuum tube opening may be trimmed off (without perforating the body of the elastic enclosure), and the remaining elastic enclosure may be rolled over the vacuum tube exterior. However, any suitable method of creating a flared opening may be used.
As shown in FIG. 2C, the step of reducing pressure within the vacuum tube to expand the elastic enclosure body S240 functions to stretch the body of the elastic enclosure to define the desired working lumen. Since the elastic enclosure body is sealed within the vacuum tube lumen (by the seal formed by folding the opening portion over the vacuum tube opening edge), a suction within the vacuum tube lumen stretches the elastic enclosure body to define the working lumen because the exterior of the elastic enclosure body (within the vacuum tube lumen) experiences a lower pressure than the interior of the elastic enclosure body. S240 is preferably accomplished by coupling the vacuum tube lumen to a vacuum pump (e.g. suction generator) and removing a portion of the air from the vacuum tube (e.g. pulling a vacuum), but may alternately be accomplished by rapidly cooling the vacuum tube lumen, or by any suitable manner that reduces pressure within the vacuum tube lumen.
In a second embodiment of S200, the working lumen is created by utilizing positive pressure within the elastic enclosure body (“positive pressure embodiment”). In a first embodiment of the positive pressure embodiment (“enclosure-stretching apparatus lumen stretching” embodiment), as shown in FIG. 6, the fingers of a tube-stretching apparatus are inserted into the lumen of the elastic enclosure S237 a and incrementally radially expanded to achieve the desired working lumen S237 b. The fingers are preferably inserted in the lumen to a depth substantially equal to the desired length of the working lumen, and the fingers are preferably expanded to form a substantially circular working lumen cross section of the working diameter, but may alternatively be expanded to form an ovular lumen cross section, a bean-shaped lumen cross section, or any suitable cross section. In this embodiment, the fingers of the enclosure-stretching apparatus are preferably strong enough to withstand deformation from the restitution force of the elastic enclosure. In a second embodiment of the positive pressure embodiment, the interior of the elastic enclosure is preferably pressurized and expanded to form the working lumen. This is preferably accomplished by fluidly coupling the elastic enclosure opening to a pressurized fluid source (e.g. by placing the elastic enclosure opening over the source's fluid nozzle and securing a washer over the arrangement), wherein the pressurized fluid source is preferably compressed fluid that comprises compressed air (e.g. from a canister or from an air compressor), but may alternately comprise compressed liquid or any suitable fluid. The positive pressure is then preferably maintained throughout the step of orienting the fuel insert within the working lumen S300.
The step of orienting the fuel insert within the working lumen S300 functions to ensure that the elastic enclosure restitutes over the insert in a desired configuration (shown in FIG. 1). Furthermore, S300 may additionally ensure that other components placed within the working lumen are aligned properly relative to each other. As shown in FIG. 7, S300 preferably includes the steps of maintaining the working lumen S310; positioning the fuel insert relative to the working lumen opening S320; and inserting a portion of the fuel insert into the working lumen S330. The step of maintaining the working lumen S310 functions to keep the working lumen in the desired configuration, and is preferably accomplished by maintaining the stretching force on the elastic enclosure body (e.g. by maintaining the vacuum in the vacuum tube lumen). The step of positioning the fuel insert S320 preferably readies the assembly for fuel insert insertion into the working lumen. This is preferably accomplished by approximately aligning the longitudinal axes of the fuel insert and the working lumen, but may alternately be accomplished in any suitable manner for any desired orientation. The step of positioning the fuel insert S320 may additionally include the step of positioning additional components relative to the fuel insert. For example, the reaction chamber may include an exhaust nozzle that facilitates reaction product flow out of the reaction chamber, wherein the exhaust nozzle is coupled to the fuel insert within the elastic enclosure. In this example, the exhaust nozzle is placed on one end of the fuel insert (preferably on top, wherein the fuel insert is standing on its end). The step of positioning the fuel insert S320 may additionally utilize a guide 210, wherein the guide may be disposed on the interior of the working lumen and extracted later, be disposed on the fuel insert, or be disposed on the exterior of the elastic enclosure. The guide preferably has or creates geometry that orients the fuel insert in the desired orientation, wherein the fuel insert has complimentary geometry to the guide. The guide may additionally couple or align multiple components in a desired configuration. For example, if multiple fuel inserts are to be inserted into the elastic enclosure, the guide may be used along a side of the inserts to ensure relative position retention. The guide is preferably an alignment rod, but may alternatively be alignment patterns, guide rails, a clip, or any other suitable guide. The guide is preferably formed as an integral piece of the fuel insert or as an integral piece of the elastic enclosure, but may alternatively be a separate piece that couples to the elastic enclosure and/or fuel insert, wherein the separate guide is removed after fuel insert insertion into the working lumen or after elastic enclosure restitution. The step of positioning the fuel insert S320 preferably includes the steps of orienting the fuel insert on end and inverting the working lumen over the fuel insert. However, the fuel insert may be positioned over the working lumen, wherein the working lumen opening faces upward, or be positioned to the side of the working lumen, wherein the working lumen opening faces the fuel insert. The step of inserting a portion of the fuel insert into the working lumen S330 functions to control the longitudinal coverage of the elastic enclosure over the fuel insert. The step of inserting a portion of the fuel insert into the working lumen S330 preferably includes advancing the fuel insert into the working lumen; and halting advancement when the desired depth is reached. The fuel insert may be advanced by moving the fuel insert into the working lumen, by moving the working lumen over the fuel insert, or by advancing both the fuel insert and the working lumen toward each other. The fuel insert is preferably advanced along one axis, wherein the other axes are held constant (e.g. no rotation), but may alternatively rotate as it is inserted into the working lumen. The fuel insert orientation relative to the working lumen opening is preferably fixed in all axes of rotation and translation except for the axis of insertion. Fuel insert insertion is preferably halted at a depth substantially near the desired longitudinal coverage distance, wherein the portion of the fuel insert to be encapsulated by the elastic enclosure is preferably inserted until the uninserted portion of the fuel insert has a length substantially equal to the combined length of the desired fuel insert external section and the opening portion of the elastic enclosure, wherein the opening portion of the elastic enclosure is unrolled/unfolded to cover the fuel insert after restitution. However, the fuel insert may alternatively be inserted any desired distance. For example, if the fuel insert is desired to be entirely encapsulated by the elastic enclosure (e.g. the desired longitudinal coverage distance is the entire length of the fuel insert), then the fuel insert is entirely inserted into the working lumen, and may be dropped in, pushed in, guided in, or any suitable manner of placing the entire fuel insert into the working lumen.
The step of restituting the elastic enclosure over the fuel insert S400 functions to create continuous contact between the elastic enclosure and the fuel insert, (shown in FIG. 1). S400 is preferably achieved by releasing the stretching force on the elastic enclosure body, and relying on the elasticity of the elastic enclosure to achieve restitution about the fuel insert. In the vacuum embodiment, S400 preferably includes the step of releasing the suction in the vacuum tube. In the positive pressure embodiment, S400 preferably includes removing the pressure generation mechanism (e.g. contracting together and/or removing the enclosure-stretching apparatus fingers, releasing the pressure within the elastic enclosure interior). However, this step may alternatively heat the elastic enclosure such that it shrinks about the fuel insert, cinch the elastic enclosure about the fuel insert with elastic bands, pull a vacuum on the fuel insert-elastic enclosure assembly, or utilize any other suitable method of restituting the elastic enclosure over the fuel insert. S400 may additionally include the step of retaining the fuel insert position during restitution, which functions to achieve the desired fuel insert-elastic enclosure positioning after restitution. Because the elastic enclosure is compressing over the fuel insert during restitution, the inserted orientation (insertion distance, relative positioning of components, etc) may change. This step is preferably accomplished by holding the fuel insert in the desired position relative to the working lumen opening and possibly adjusting (e.g. pushing and/or pulling) the fuel insert position relative to the working lumen opening. S400 may additionally include the step of unsealing the elastic enclosure openings, wherein the elastic enclosure opening seals are removed (e.g. cut off, unclipped, untied, etc.).
As shown in FIG. 8, the method of manufacturing a reaction chamber may additionally include the step of inserting a liquid delivery mechanism S500, which functions to create a fluid pathway between the exterior of the reaction chamber and the reaction zone within the reaction chamber through which liquid reagent can flow. The outlet end (reaction end) of LDM is preferably inserted into the elastic enclosure through the elastic enclosure opening, and is preferably inserted along the fuel insert length such that the outlet end is substantially near the fuel insert end distal the elastic enclosure opening (i.e. the LDM is inserted such that it encompasses substantially the entire length of the fuel insert). However, the LDM may be inserted through any other opening into the elastic enclosure. The LDM may alternatively/additionally be inserted such that it encompasses only a portion of the fuel insert (e.g. three-quarters, half, one-third, etc. of the fuel insert length), inserted from the side, or inserted in any suitable configuration. The LDM is preferably inserted between the elastic enclosure and the fuel insert, more preferably within a groove or channel in the fuel insert (wherein the groove may also function as the guide groove), but may alternatively/additionally be inserted into the fuel insert. If a portion of the fuel insert is left outside the elastic enclosure, the LDM is preferably inserted from the end with the uncovered fuel insert. In a first embodiment of S500, the LDM is inserted after restitution of the elastic enclosure (S400). As shown in FIG. 8A, the first embodiment of step S500 preferably includes the steps of lifting the elastic enclosure away from the fuel insert S522; orienting the LDM S524; and inserting the LDM into the reaction chamber S526. Lifting the elastic enclosure away from the fuel insert S522 functions to create a space for LDM insertion, and is preferably performed where the LDM is desired to be inserted. S522 is preferably performed by inserting a lifting mechanism (e.g. a spatula, shim, rod, etc.) between the elastic enclosure and the fuel insert at the desired position and prying the elastic enclosure away from the fuel insert. However, any suitable method of creating an insertion space for the LDM may be utilized. Orienting the LDM S524 functions to insert the LDM in the correct configuration relative to the reaction chamber. The LDM is preferably oriented such that the outlet is inserted into the reaction chamber first, but may be oriented in any suitable configuration. Inserting the LDM into the reaction chamber S526 functions to achieve the desired LDM depth, placing the LDM outlet(s) in the desired position(s) relative to the fuel insert. The LDM is preferably pushed in through the insertion space, but may alternatively be guided in, wherein a guide (e.g. fishing wire) is initially threaded through the desired LDM pathway and the LDM is threaded over the guide. The LDM may alternatively be inserted using any other suitable method. In a second embodiment of step S500, as shown in FIG. 8B, the LDM is inserted before restitution of the elastic enclosure over the fuel insert (S400). In this embodiment, the LDM is oriented to the desired configuration and position, inserted between the elastic enclosure and the fuel insert, and retained in its position relative to the fuel insert until elastic enclosure restitution.
As shown in FIG. 9, the method of manufacturing a reaction chamber may additionally include sealing the elastic enclosure opening about the LDM S600. This step functions to establish and maintain a fluid seal about the fuel insert and reaction zone, such that reagents and reaction products do not leak out from the LDM end, and to retain the LDM position. This step is preferably used when the LDM inlet of the elastic enclosure is a separate opening from the reaction product outlet, but may be used when the LDM inlet uses the same elastic enclosure opening as the reaction product outlet. Shoo preferably accomplished by allowing restitution of the elastic enclosure about the LDM, compressing the LDM against the fuel insert, but may be accomplished by cinching and tightening the elastic enclosure opening over the LDM with a cinture placed over the elastic enclosure substantially near the elastic enclosure opening, by heating and shrinking the elastic enclosure about the LDM, by melting the elastic enclosure to the LDM, by applying a sealant to the gap between the LDM and elastic enclosure, or by any other suitable sealing method.
As shown in FIG. 10, the method of manufacturing a reaction chamber may additionally include the step of trimming a portion of elastic enclosure from the reaction chamber S700. This step functions to control the size of the reaction chamber, to ensure adequate fuel insert retention within the elastic enclosure, and to achieve an adequate reaction product outlet. Excess elastic enclosure (e.g. elastic enclosure not contacting the fuel insert and/or LDM) is preferably trimmed off after restitution of the elastic enclosure over the insert, and may be repeated after LDM insertion or after sealing the elastic enclosure opening about the LDM. However, the elastic enclosure may be trimmed (e.g. cut) to widen existing openings (e.g. widen the opening about the exhaust nozzle, if used), or to create additional openings, for example reaction product outlet(s), in desired positions along the elastic enclosure. This step is preferably performed with a razor, but may alternately be performed by laser cutting, shearing, or any other suitable trimming method.
The method of manufacturing a reaction chamber may additionally include repeating any of the aforementioned steps, preferably at least S200, S300, and S400, for additional elastic enclosures, such that the fuel insert is encapsulated by two or more elastic enclosures.
As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the preferred embodiments of the invention without departing from the scope of this invention defined in the following claims.

Claims

1. A method for manufacturing a reaction chamber, the reaction chamber having a fuel insert and an elastic enclosure, the elastic enclosure having a body and an opening portion that defines an opening in the elastic enclosure, the method comprising the steps of:

a) stretching the body of the elastic enclosure to define a working lumen;

b) orienting the fuel insert within the working lumen; and

c) restituting the elastic enclosure over the insert.

2. The method of claim 1, wherein step (a) further includes the steps of:

placing the body of the elastic enclosure within a vacuum tube, wherein the opening of the elastic enclosure is disposed outside the vacuum tube;

securing the elastic enclosure opening portion to the vacuum tube opening, thereby sealing the vacuum tube opening; and

defining a working lumen in the elastic enclosure by pulling a suction within the vacuum tube to expand the elastic enclosure body.

3. The method of claim 2, wherein step (a) further includes the step of sealing the elastic enclosure to leave one opening.

4. The method of claim 3, wherein the elastic enclosure is a tube, and the end opposing the opening is sealed.

5. The method of claim 2, wherein step (c) includes the step of releasing the suction within the vacuum tube.

6. The method of claim 2, wherein the step of securing the elastic enclosure opening portion to the vacuum tube opening includes disposing the elastic enclosure opening portion in a fold over the vacuum tube opening, such that the body of the elastic enclosure is encapsulated within the vacuum tube lumen and the elastic enclosure opening portion is disposed outside the vacuum tube.

7. The method of claim 6, wherein disposing the elastic enclosure opening portion in a fold over the vacuum tube opening comprises the steps of:

folding the elastic enclosure opening portion over a stretching apparatus;

stretching the elastic enclosure opening portion radially to a diameter larger than the vacuum tube diameter;

sliding the vacuum tube into the fold between the elastic enclosure opening portion and the elastic enclosure body; and

transferring the folded elastic enclosure to the vacuum tube.

8. The method of claim 6, wherein the elastic enclosure opening portion has substantially the same diameter as the body.

9. The method of claim 6, wherein the elastic enclosure is stretched prior to disposing the elastic enclosure opening portion in a fold over the vacuum tube opening.

10. The method of claim 6, wherein the elastic enclosure opening portion is flared outward from the body.

11. The method of claim 10, wherein a portion of the flared opening has a diameter larger than the vacuum tube diameter.

12. The method of claim 10, wherein the method further includes the step of flaring the elastic enclosure opening portion, which includes the steps of:

placing a portion of the elastic enclosure body within the vacuum tube lumen while leaving a second portion of the elastic enclosure outside the vacuum tube, wherein the second portion is proximal to the elastic enclosure opening portion;

coupling the elastic enclosure opening to a pressure source; and

pressurizing the elastic enclosure such that a section of the second portion is flared to a diameter larger than the vacuum tube diameter.

13. The method of claim 12, wherein the step of disposing the elastic enclosure opening portion in a fold over the vacuum tube opening includes the step of pushing the flared portion of the elastic enclosure over the exterior of the vacuum tube.

14. The method of claim 2, wherein step (a) further includes the step of lubricating the vacuum tube.

15. The method of claim 1, wherein step (b) further includes the steps of:

positioning the fuel insert relative to the working lumen opening; and

inserting a portion of the fuel insert into the working lumen.

16. The method of claim 15, wherein the step of positioning the fuel insert includes using a guide.

17. The method of claim 16, wherein the fuel insert includes multiple pieces, and the guide retains the relative positions of the multiple pieces.

18. The method of claim 15, wherein the fuel insert is fully inserted into the working lumen.

19. The method of claim 15, wherein the step of inserting a portion of the fuel insert into the working lumen includes the step of inverting the working lumen over the fuel insert.

20. The method of claim 1, wherein step (c) includes the step of maintaining the fuel insert position within the working lumen.

21. The method of claim 1, further comprising the step of inserting a liquid delivery mechanism between the fuel insert and the elastic enclosure.

22. The method of claim 21, wherein the step of inserting a liquid delivery mechanism occurs before the step of restituting the elastic enclosure over the fuel insert, wherein the step of inserting a liquid delivery mechanism includes the steps of:

positioning the liquid delivery mechanism within the working lumen; and

maintaining the liquid delivery mechanism position during restitution.

23. The method of claim 21, wherein the step of inserting a nozzle occurs after the step of restituting the elastic enclosure over the insert, wherein the step of inserting a liquid delivery mechanism includes the steps of:

stretching a portion of the elastic enclosure away from the insert;

positioning the liquid delivery mechanism between the insert and the elastic enclosure; and

releasing the portion of the elastic enclosure.

24. The method of claim 1, further comprising the step of trimming the excess restituted elastic enclosure from the reaction chamber.

25. The method of claim 1, wherein steps (a), (b) and (c) are repeated for a second elastic enclosure, wherein the fuel insert is encapsulated in a first elastic enclosure.

26. A method for manufacturing a reaction chamber, the reaction chamber comprising a metal hydride insert and an elastic enclosure, the elastic enclosure including a body and an opening portion that defines an opening in the elastic enclosure, the method comprising:

placing the body of the elastic enclosure within a vacuum tube, wherein the opening portion of the elastic enclosure is disposed outside the vacuum tube;

securing the elastic enclosure opening portion to the vacuum tube opening, thereby sealing the vacuum tube opening;

defining a working lumen in the elastic enclosure by reducing air pressure within the vacuum tube to expand the elastic enclosure body;

maintaining constant vacuum tube pressure when the elastic enclosure is stretched to a desired working lumen size;

orienting the metal hydride insert within the working lumen;

maintaining the insert orientation; and

allowing pressure increase within the vacuum tube to allow restitution of the elastic enclosure about the insert.

27. The method of claim 26, further comprising the step of inserting a liquid delivery mechanism between the insert and the elastic enclosure.

28. The method of claim 26, wherein the step of securing the elastic enclosure opening to the vacuum tube opening includes disposing the elastic enclosure opening in a fold over the vacuum tube opening edge, such that the body of the elastic enclosure is enclosed within the vacuum tube lumen and the elastic enclosure opening is disposed on the vacuum tube exterior.

29. The method of claim 28, wherein the step of disposing the elastic enclosure opening in a fold over the vacuum tube opening includes the steps of:

folding the elastic enclosure opening portion over a stretching apparatus;

stretching the elastic enclosure opening portion radially to a diameter larger than the vacuum tube opening diameter;

transferring the folded elastic enclosure to the vacuum tube.

30. The method of claim 28, wherein the elastic enclosure opening portion is flared outward from the body, and the step of disposing the elastic enclosure opening in a fold over the vacuum tube opening includes the step of stretching the flared opening over the vacuum tube opening.

31. The method of claim 30, further comprising the step of flaring the opening, which includes the steps of:

placing a portion of the elastic enclosure body within the vacuum tube lumen while leaving a second portion of the elastic enclosure outside the vacuum tube, wherein the second portion includes the elastic enclosure opening portion;

coupling the elastic enclosure opening to a pressure source; and

pressurizing the elastic enclosure such that the second portion of the elastic enclosure is flared to a diameter larger than the vacuum tube diameter;

wherein the step of disposing the elastic enclosure opening in a fold over the vacuum tube opening includes the step of pushing the flared portion of the elastic enclosure over the exterior of the vacuum tube.