High-temperature spring for dynamic catalyst rocket engine

Abstract

A catalyst enclosure includes a housing, a catalyst bed region, a bedplate that is translatable in the catalyst bed region, and a spring. The bedplate has a first side facing the catalyst bed region and a second side opposite the first side. The spring is located at the second side of the bedplate and is configured to apply a bias force to the bedplate that causes the bedplate to translate in the catalyst bed region and thereby reduce a volume of the catalyst bed region.

Description

HIGH-TEMPERATURE SPRING FOR DYNAMIC CATALYST ROCKET ENGINEBACKGROUND

[0001] In a monopropellant dynamic catalyst rocket engine, monopropellant is injected through a catalyst bed to generate high-temperature gases that are then expelled through a nozzle to produce thrust. Over time, some of the catalyst may be lost in the gas flow. Such a loss may create voids in the catalyst bed that are undesirable for good performance of the catalyst to react with the monopropellant. As a result, a spring or springs are used to compress the catalyst bed. The compression collapses any voids that occur and thus facilitates maintaining a high packing density of the catalyst.SUMMARY

[0002] A catalyst enclosure according to an example of the present disclosure includes a housing, a catalyst bed region, a bedplate that is translatable in the catalyst bed region, and a spring. The bedplate has a first side facing the catalyst bed region and a second side opposite the first side. The spring is located at the second side of the bedplate and is configured to apply a bias force to the bedplate that causes the bedplate to translate in the catalyst bed region and thereby reduce a volume of the catalyst bed region.

[0003] In a further embodiment of any of the foregoing embodiments, the at least the spring is formed of a composite material including ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed. The metal matrix includes, by weight percent, 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01-0.1% carbon, 0-1.0% titanium, and a balance of nickel.

[0004] In a further embodiment of any of the foregoing embodiments, the bedplate is also formed of the composite material.

[0005] In a further embodiment of any of the foregoing embodiments, the bedplate and the spring are metallurgically bonded together.

[0006] In a further embodiment of any of the foregoing embodiments, the spring is a helical spring having a first axial end with a first end coil, a second axial end with a second end coil, and the second end coil is metallurgically bonded to the second side of the bedplate.

[0007] In a further embodiment of any of the foregoing embodiments, the housing is a convergent-divergent nozzle and is also formed of the composite material.

[0008] In a further embodiment of any of the foregoing embodiments, the spring and the convergent-divergent nozzle are metallurgically bonded together.

[0009] In a further embodiment of any of the foregoing embodiments, the first end coil is metallurgically bonded to the convergent-divergent nozzle.

[0010] A further embodiment of any of the foregoing embodiments includes comprising an injector attached with the convergent-divergent nozzle, the injector including a chamber defining, at least in part, the catalyst bed region.

[0011] A further embodiment of any of the foregoing embodiments includes catalyst particles disposed in the catalyst bed.

[0012] In a further embodiment of any of the foregoing embodiments, the spring is a disc spring.

[0013] In a further embodiment of any of the foregoing embodiments, the spring is a wave spring.

[0014] In a further embodiment of any of the foregoing embodiments, the spring is selected from the group consisting of a helical spring, a disc spring, and a wave spring.

[0015] In a further embodiment of any of the foregoing embodiments, the bedplate and the convergent-divergent nozzle are formed of metallic alloys that differ in composition from the metal matrix.

[0016] A rocket engine according to an example of the present disclosure includes a convergent-divergent nozzle and an injector attached with the convergent-divergent nozzle. The injector includes a chamber defining, at least in part, a catalyst bed region. A bedplate is translatable in the chamber and has a first side facing the catalyst bed region and a second side opposite the first side. A spring is located at the second side of the bedplate and is configured to apply a bias force to the bedplate that causes the bedplate to translate in the chamber and thereby reduce a volume of the catalyst bed region. At least the spring is formed of a composite material including ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01-0.1% carbon, 0-1.0% titanium, and a balance of nickel.

[0017] A rocket engine article according to an example of the present disclosure includes a bedplate having a first side and a second side opposite the first side, and a spring metallurgically bonded to the second side of the bedplate. The spring and the bedplate are formed of a composite material including ceramic particles including yttrium oxide, hafniumoxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35 cobalt, 26-31 chromium, 0-1.0 aluminum, 0-3.0 rhenium, 0.01-0.1 carbon, 0- 1.0 titanium, and a balance of nickel.

[0018] In a further embodiment of any of the foregoing embodiments, the spring is a helical spring having a first axial end with a first end coil, a second axial end with a second end coil, and the second end coil is metallurgically bonded to the second side of the bedplate.

[0019] The rocket engine article as recited in claim 17, further comprising a convergent-divergent nozzle that is attached with the spring, and the convergent-divergent nozzle is also formed of the composite material.

[0020] In a further embodiment of any of the foregoing embodiments, the spring and the convergent-divergent nozzle are metallurgically bonded together.

[0021] In a further embodiment of any of the foregoing embodiments, the first end coil is metallurgically bonded to the convergent-divergent nozzle.

[0022] The present disclosure may include any one or more of the individual features disclosed above and / or below alone or in any combination thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

[0024] Figure 1 illustrates a preassembly view of an example rocket engine.

[0025] Figure 2 illustrates the assembled engine with a helical spring.

[0026] Figure 3 illustrates another example engine with a disc spring.

[0027] Figure 4 illustrates another example engine with a wave spring.

[0028] In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-hundred or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding elements. Terms such as “first” and “second” used herein are to differentiate that there are two architecturally distinct components or features. Furthermore, the terms “first” and “second” are interchangeable in that a first component or feature could alternatively be termed as the second component or feature, and vice versa.DETAILED DESCRIPTION

[0029] Figure 1 schematically illustrates a preassembly view of selected portions of an example rocket engine 20, and Figure 2 illustrates the assembled engine 20. The engine 20 is a monopropellant dynamic catalyst bed engine. In general, the engine 20 operates to produce thrust by the exothermic decomposition of monopropellant over a suitable catalyst. The engine 20 includes a housing, which in this example is a convergent-divergent nozzle 22, and an injector 24 attached with the convergent-divergent nozzle 22. The injector 24 includes a chamber 26 that defines, at least in part, a catalyst bed region 28. The catalyst bed region 28 is a volume in which a particulate catalyst 29 is held. The injector 24 includes one or more injector passages 24a through which the monopropellant is provided into the catalyst bed region 28.

[0030] There is also a bedplate 30 that is translatable in the chamber 26 (as indicated at arrow T in Figure 2). The bedplate 30 has a first side 30a that faces the catalyst bed region 28 and a second side 30b opposite the first side. As an example, the bedplate 30 includes through-slots (or holes) 30c that are sized to permit gas flow there through. The slots 30c may be covered by a screen (not shown) that is of a suitable mesh size to block the catalyst29 from escaping from the chamber 26 through the slots 30c. The first side 30a of the bedplate30 thus serves to bound one side of the catalyst bed region 28 and thereby contain the catalyst 29 in the chamber 26.

[0031] A spring 32 is located at the second side 30b of the bedplate 30 and is configured to apply a bias force (see F in Figure 2) to the bedplate 30. The bias force causes the bedplate 30 to translate in the chamber and thereby reduce a volume of the catalyst bed region 28. As the catalyst 29 is present, the bias force compresses the catalyst 29 to maintain a good packing density to facilitate a high surface area of exposure for the monopropellant (e.g., hydrazine). However, as the catalyst 29 reacts it may erode over time into smaller particle sizes that can escape from the chamber 26. Such a loss of catalyst 29 from the chamber 26 may create voids that are undesirable for monopropellant performance. The spring 32 maintains the bias force on the bedplate 30 in order to continually compress the catalyst 29 and thereby facilitate collapsing any void volume that is created and maintain a high packing density. Together, the nozzle 22 (housing), the bedplate 30, spring 32, and catalyst bed region 28 are considered to be a catalyst enclosure. It is to be appreciated, however, that although the examples herein are demonstrated in the rocket engine 20, the disclosure is applicable to catalyst enclosures in other high temperature environments, such as but not limited to chemical fixed bed reactors, hydrocarbon reformers, hydrogenation beds, CO scrubbers, and chemical conversion beds, orin low temperature environments, such as automotive catalytic converters, CO scrubbers in compressed breathing air, respirators, and escape masks.

[0032] Hot gases from the reaction of the monopropellant are expelled through the bedplate 30, through the spring 32, and into the convergent-divergent nozzle 22 to produce thrust. As a result, the spring 32 can be exposed to temperatures of more than 1700°F. Some nickel or nickel-chromium alloys have high temperatures resistance and can maintain good mechanical properties at such temperatures. However, at such high temperatures, even those alloys may be subject to high temperature creep and thus life-limited. In this regard, at least the spring 32 herein is formed of an oxide dispersion strengthened composite material 34 (inset in Figure 1) that has superior strength and high temperatures properties that enable longer life.

[0033] The composite material 34 includes ceramic particles 34a that are dispersed in a metal matrix 34b. The ceramic particles 34a include one or more of yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, and thorium oxide. In a further example, the ceramic particles 34a are nano-sized. The ceramic particles 34a serve to improve the strength properties, creep properties, and oxidation properties of the composite material 34. As an example, the amount of ceramic particles, by weight percentage of the total weight of the composite material 34, is up to 2%, such as 0.5% to 2%.

[0034] The metal matrix 34b includes, by weight percent (of the total weight of the metal matrix), 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01- 0.1% carbon, 0-1.0% titanium, and a balance of nickel. In a further example, the composite material 34 is as set forth in U.S. Application 16 / 906,319, incorporated herein by reference in its entirety.

[0035] In a further example, the bedplate 30 is also formed of the composite material 34. For instance, the bedplate 30 and the spring 32 are metallurgically bonded together. As shown, the spring 32 in this example is a helical spring that has a first axial end El with a first end coil 32a, a second axial end E2 with a second end coil 32b. The second end coil 32b is metallurgically bonded to the second side 30b of the bedplate 30.

[0036] In yet a further example, the convergent-divergent nozzle 22 is also formed of the composite material 34. For instance, the first end coil 32a is metallurgically bonded to the convergent end of the convergent-divergent nozzle 22.

[0037] The spring 32, or the spring 32 in combination with the bedplate 30 and / or convergent-divergent nozzle 22, is formed via a laser powder bed fusion additive manufacturing process. As an example, a powder of the composite material 34 is provided into a powder additive manufacturing machine, and the powder is melted and sintered layer-by-layer to form the geometry of the spring 32 or the spring 32 in combination with the bedplate 30 and / or convergent-divergent nozzle 22. After be built by additive manufacturing, the resultant article may be further processed to improve certain properties, such as by heat treatment.

[0038] Referring to Figure 1, the bedplate 30, the spring 32, and the convergent- divergent nozzle 22 are formed via additive manufacturing into a single, monolithic article. The injector 24 may be separately formed from an alloy that differs in composition from the composite material 34. The monolithic article is brought into proximity of the injector 24 such that the bedplate 30 is inserted into the chamber 26. The assembly is then subjected to an orbital welding process to provide a weld 35 that secures the monolithic article and the injector 24 together.

[0039] Figures 3 and 4 each illustrate additional examples of the engine 20. In the example of Figure 3, instead of the helical spring 32 the spring is a disc spring 132 (also known as Belleville washers or conical springs). In this case, there is a stack of four disc spring portions 132a / 132b / 132c / 132d, each comprising a conical disc geometry, in alternating orientations. The disc spring portions 132a / 132b / 132c / 132d are formed of the composite material 34 as discussed above and constitute a single, monolithic article made by additive manufacturing. As shown, the spring 132 and the bedplate 130 are separate pieces, and the bedplate 130 may be made of an alloy of a different composition. However, the spring 132 and bedplate 130 may alternatively be a single article made of the composite material 34, similar to the spring 32 and bedplate 30 of the example above.

[0040] In the example of Figure 4, instead of the helical spring 32 the spring is a wave spring 232. The wave spring 232 is formed of a thin wall 232a that includes turns and waves to produce a spring force under deflection. In some instances where compactness is desired, the wave spring 232 may be useful for its low height and low flow blockage (in comparison to a helical spring, of the same deflection and spring force). The wave spring 232 is formed of the composite material 34 as discussed above and constitute a single, monolithic article made by additive manufacturing. As shown, the wave spring 232 and the bedplate 130 are separate pieces, and the bedplate 130 may be made of an alloy of a different composition. However, the spring 232 and bedplate 130 may alternatively be a single article made of the composite material 34, similar to the spring 32 and bedplate 30 of the example above.

[0041] The composite material 34 additionally permits greater flexibility in the design of an engine. For instance, as the composite material 34 is of higher strength and hightemperature properties than some nickel and nickel-chromium alloys, there is less of a need for heat shielding in an engine design to reduce temperature impacts.

[0042] Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.

[0043] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

CLAIMSWhat is claimed is:

1. A catalyst enclosure comprising: a housing having an inlet and an outlet; a catalyst bed region; a bedplate that is translatable in the catalyst bed region, the bedplate having a first side facing the catalyst bed region and a second side opposite the first side; and a spring located at the second side of the bedplate and configured to apply a bias force to the bedplate that causes the bedplate to translate in the catalyst bed region and thereby reduce a volume of the catalyst bed region.

2. The catalyst enclosure as recited in claim 1, wherein at least the spring is formed of a composite material including: ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01-0.1% carbon, 0-1.0% titanium, and a balance of nickel.

3. The catalyst enclosure as recited in claim 2, wherein the bedplate is also formed of the composite material.

4. The catalyst enclosure as recited in claim 3, wherein the bedplate and the spring are metallurgically bonded together.

5. The catalyst enclosure as recited in claim 4, wherein the spring is a helical spring having a first axial end with a first end coil, a second axial end with a second end coil, and the second end coil is metallurgically bonded to the second side of the bedplate.

6. The catalyst enclosure as recited in claim 5, wherein the housing is a convergent- divergent nozzle and is also formed of the composite material.

7. The catalyst enclosure as recited in claim 6, wherein the spring and the convergent- divergent nozzle are metallurgically bonded together.

8. The catalyst enclosure as recited in claim 7, wherein the first end coil is metallurgically bonded to the convergent-divergent nozzle.

9. The catalyst enclosure as recited in claim 6, further comprising an injector attached with the convergent-divergent nozzle, the injector including a chamber defining, at least in part, the catalyst bed region.

10. The catalyst enclosure as recited in claim 1, further comprising catalyst particles disposed in the catalyst bed.

11. The catalyst enclosure as recited in claim 1, wherein the spring is a disc spring.

12. The catalyst enclosure as recited in claim 1, wherein the spring is a wave spring.

13. The catalyst enclosure as recited in claim 1, wherein the spring is selected from the group consisting of a helical spring, a disc spring, and a wave spring.

14. The catalyst enclosure as recited in claim 1, wherein the housing is a convergent- divergent nozzle and the at least the spring is formed of a composite material including: ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01-0.1% carbon, 0-1.0% titanium, and a balance of nickel, and the bedplate and the convergent-divergent nozzle are formed of metallic alloys that differ in composition from the metal matrix.

15. A rocket engine comprising: a convergent-divergent nozzle; an injector attached with the convergent-divergent nozzle, the injector including a chamber defining, at least in part, a catalyst bed region; a bedplate that is translatable in the chamber, the bedplate having a first side facing the catalyst bed region and a second side opposite the first side; and a spring located at the second side of the bedplate and configured to apply a bias force to the bedplate that causes the bedplate to translate in the chamber and thereby reduce a volume of the catalyst bed region, at least the spring being formed of a composite material including: ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35% cobalt, 26-31% chromium, 0-1.0% aluminum, 0-3.0% rhenium, 0.01-0.1% carbon, 0-1.0% titanium, and a balance of nickel.

16. A rocket engine article comprising: a bedplate having a first side and a second side opposite the first side; and a spring metallurgically bonded to the second side of the bedplate, the spring and the bedplate being formed of a composite material including: ceramic particles including yttrium oxide, hafnium oxide, zirconium oxide, aluminum oxide, thorium oxide, or combinations thereof, and a metal matrix through which the ceramic particles are dispersed, the metal matrix including, by weight percent, 30-35 cobalt, 26-31 chromium, 0-1.0 aluminum, 0-3.0 rhenium, 0.01-0.1 carbon, 0-1.0 titanium, and a balance of nickel.

17. The rocket engine article as recited in claim 16, wherein the spring is a helical spring having a first axial end with a first end coil, a second axial end with a second end coil, and the second end coil is metallurgically bonded to the second side of the bedplate.

18. The rocket engine article as recited in claim 17, further comprising a convergent- divergent nozzle that is attached with the spring, and the convergent-divergent nozzle is also formed of the composite material.

19. The rocket engine article as recited in claim 18, wherein the spring and the convergent- divergent nozzle are metallurgically bonded together.

20. The rocket engine article as recited in claim 19, wherein the first end coil is metallurgically bonded to the convergent-divergent nozzle.

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