(NOT APPLICABLE)
Fluid flow devices (e.g., pipes, valves, nozzles and the like) subjected to thermal shocks in severe industrial applications can benefit from thermal protection to reduce thermal stresses, mitigate the effects of thermal shock experienced and prevent premature thermal fatigue. Fluid flow devices subject to cyclic high pressure and temperature changes make them prone to failure due to thermal shock. Thermal shock refers to a process wherein the flow device experiences sudden large magnitude changes in thermal stress when the heat flux and temperature gradient experienced by the flow device change abruptly.
Thermal shock damage can be found in various severe service industries (e.g., in a catalyst injection valve and its connection pipes in an ebullated bed hydro-processing ore refining application). In the case of an ebullated bed hydro-processing system, for instance, cracking of valve body and metal valve seats has been observed when valves are exposed to temperatures and pressures of up to 850° F. and 3,500 psi at 4-10 cycles per day. Cracking is thought to occur due to initial thermal stresses experienced when the valve is opened to experience such high temperature and pressure after several hours of having remained closed and therefore having reached ambient temperature. This phenomenon is especially observed during winter when external ambient temperature drops (e.g., to as low as −40° F.) and pre-heating systems fail.
Over the years, several innovations have been presented to help mitigate the effects of temperature surges and, in some cases, proposed solutions have been adopted. Some of the attempted solutions currently in use include use of materials having low thermal conductivity, use of pre-heating systems, use of thermal barrier coatings which are highly refractive, etc. While these attempted solutions have achieved some level of success, they continue to present shortcomings which are here addressed by several example embodiments of improved thermal insulating sleeve liners for fluid flow devices used in severe industrial applications.
Pre-heating systems have proven to be unreliable. There are reported cases where pre-heating systems malfunctioned and resulted in valve operations being carried out without pre-heating. Cracking of the valve body is especially observed when this occurs, and regular maintenance is required to avoid such incidents. This may be costly but even then normal operation is not guaranteed, especially during harsh weather conditions.
Adoption of low thermal conductivity materials has been proven not as effective since cracking could still be observed on the bodies of flow devices. This is a clear indication of their susceptibility to extreme cyclic temperatures. This led to the adoption of thermal barrier coatings (TBCs). While TBCs have generally been more effective in providing thermal shock protection, they too have several limitations. TBCs are susceptible to erosion and corrosion, especially in instances where they are in the flow path. TBC is typically applied by thermal spray. TBCs require laborious and expensive processes for their preparation which results in high initial costs. And TBCs are notoriously brittle and prone to cracking, corrosion and erosion. Sleeves with TBCs need to be frequently replaced.
Some non-exhaustive examples of prior thermally insulating sleeve liners or other thermally protective internal interfaces for fluid flow devices can be found, for example, in the following prior published US patent documents: Newberg U.S. Pat. No. 7,017,604; Williams, Jr., et al. U.S. Pat. No. 8,783,279; Hofmann US 2018/0051834; and Zhu et al. US 2018/0209322.
The present document describes an improved, preferably additively manufactured (e.g., by 3D printing), thermal insulating sleeve liner constructed of a suitable material for the serviced application (e.g., Inconel 718® or other austenitic nickel-chromium-based super-alloys, high nickel alloys and the like or ceramic and/or composite materials of various types recognized by those in the art as being suitable for certain severe service applications) with an internal infill structural pattern creating internal voids which increase thermal insulation properties while yet remaining structurally adequate to serve as a thermal insulating flow device liner for the serviced application. Preferably the infill is sized to maximize strength (i.e., to support internal/external pressures to be experienced by the sleeve) while concurrently also minimizing heat transfer (i.e., from the inside to the outside of the sleeve). Multi-layer material could also be used if the sleeve is made with wear-resistant, corrosion-resistant, low thermal conductivity materials. When a 3D printed sleeve comes out of the printer, it is in a green state. Subsequently parts can be subjected to hot isostatic pressing (sometimes referred to as being “hipped”) and/or heat treated to reduce porosity and increase mechanical properties respectively. Based on testing, all these three states are believed to work. In some embodiments, a ceramic coating may be applied either to the internal surface of the thermal insulating sleeve liner or to the internal surface of the flow device before the sleeve is inserted. Applying the coating on the internal surface of the sleeve enhances both the sleeve's insulation capacity and its wear resistance, while applying it on the internal surface of the flow device before inserting the sleeve enhances the sleeve's insulation capacity, without a corresponding enhancement in its resistance to wear. The ceramic coating in some embodiments is brushed-on. It is noted that, even though both are ceramic, the mechanical and thermal properties of the ceramic coating of example embodiments are different from those of TBC.
An object of example embodiments described herein is to provide a thermal protection device with varying designs based on the method of manufacture and intended application.
In one example embodiment, an additively manufactured (i.e., 3D printed) thermal sleeve includes two spaced-apart cylindrical shells and an internal infill pattern of integrally-formed supporting structure there-between. This thermally insulating sleeve is fitted into the flow path of the protected flow device (e.g., valves, pipes and the like). The sleeve could be locked by an interference fit with the body. Other locking methods such as brazing, welding or one or more retaining rings could be considered as well. The infill may have variable patterns that may be in the form of, but not limited to, centroidally-directed lattices, hollow honeycomb-like structures and so forth. These patterns form a porous network of supporting structure containing voids between the two shells. This network of structure entraps air (or other insulating material such as an inert nitrogen gas or an insulating vacuum) thus allowing for heavy internal insulation of flow devices to prevent or reduce thermal shock therein. Tessellations or other structural patterns inside the sleeve allow for free design of infill percentage making it customizable depending on process requirements and parameters. The end of the sleeve may be left open or fused. For sleeves having fused ends, the air-tight infill patterned region or chamber can be vacuumed or pressurized (e.g., with air or an inert gas).
In another example embodiment, a pressure equilibrium hole can be made on or through the sleeve. While the sleeve can remain acting as if a solid air-tight structure, the pressure equilibrium hole ensures a pressure balance between its inner and outer surfaces.
In another example embodiment, a non-encapsulated thermal sleeve is slip-fitted into a flow device bore. This sleeve can have variable exterior protruding surface patterns which can change depending on process requirements. Examples of these may include axially ribbed or radially ribbed exterior protruding surface patterns. Exterior surface patterns reduce the surface area in thermal contact with the interior bore body of the flow device while still allowing air entrapment there-within. This device is preferably additively manufactured (e.g., by 3D printing) although some embodiments may be manufactured by other processes. Depending on the application, the thermal sleeve may have a wear and abrasion resistant layer on its inner surface. Such functional graded layers can be deposited either by conventional deposition methods (such as a spray of thermal material) or by additive manufacturing (i.e., 3D printing) processes.
For an example embodiment installed in a flow device, the different sleeve concepts may be capped (e.g., using a separate circumferential ring-shaped cap structure) or they may have an integrally-formed circumferential ring-shaped lip in other embodiments to secure and/or locate the sleeve within the flow device. The lipped sleeve may be produced as a single piece while the capped sleeve has two distinct parts: the main sleeve part and the securing cap part. The lip or cap can interact with a larger diameter bore section at a proximal end of the main sleeve part and a narrower diameter bore section at the other distal end of the main sleeve part (so as to locate and trap the main sleeve part at a desired location within the flow device bore). The cap may be of the same material as the sleeve or of the same or similar material as the flow device. The securing cap can be welded to the flow device on the proximal larger diameter bore section after the main sleeve part has been snug-fit into a main bore length against the end face of a smaller diameter distal bore section thus retaining the main sleeve part at a desired location. The lip of a lipped sleeve, if that is used instead of a separate cap ring, can be similarly welded directly to the body of the flow device at the larger diameter proximal bore section to retain the sleeve at a desired location.
Some example embodiments of an improved additively manufactured thermal insulating sleeve liner are sized to have an outside dimension and surface area purposefully smaller than the inside dimension and surface area of the protected flow device, thereby reducing sleeve liner thermal contact with the protected flow device and thus enhancing its thermal protection. Dimensions should provide the loosest possible fit so long as it does not permit or cause excessive vibration or permit ingress of thermally conductive material in use. In some embodiments, a loose fit clearance of a few thousands of an inch (e.g., on the order of 0.002 inch) may be suitable.
Some example embodiments of the improved additively manufactured thermal insulating sleeve liner may include spaced-apart external (i.e., outwardly protruding) structures to insure less thermal contact with the internal surface of a protected flow device thus further reducing sleeve liner thermal contact with the protected flow device and enhancing its thermal protection.
Some example embodiments of the improved additively manufactured thermal insulating sleeve liner may include an integrally formed larger diameter lip at one end to assist in locating and/or retaining the sleeve liner properly within the protected flow device. Such a locating/retaining end lip (e.g., a diameter larger than the main sleeve liner body to retain a respectively associated end at a proper location in use) may also be formed as a separate retaining cap-ring structure that is secured (e.g., by a few tack or seal welds) at a proper location within the protected flow device.
Some example embodiments of the improved additively manufactured thermal insulating sleeve liner are installed within a protected flow device so as to provide an integrated flow device product incorporating the improved thermal insulating sleeve. However in use, due to wear and/or other deterioration in use, it will likely be necessary to periodically remove the thermal insulating sleeve (e.g., by breaking spot or seal welds holding it in place) and replace it with a new or refurbished thermal insulating sleeve. And if a flow device is not initially provided with the improved additively manufactured thermal insulating sleeve, then one can be retro-fitted into the flow device to thereafter provide desired thermal protection. In some embodiments, a ceramic coating may be applied to the internal surface of the flow device prior to the insertion of the thermal insulating sleeve in order to improve the thermal insulating properties of the sleeve.
The improved additively manufactured thermal insulating sleeve liner is preferably constructed so as to prevent ingress of thermally conductive materials (e.g., catalyst particles which may typically be on the order of 0.8-1.0 mm in diameter with active metal catalysts, fines, and/or coke) into internal voids of the insulating sleeve or between the outer sleeve surface and the internal surface of the protected flow device. In this way the thermal insulating and protective properties of the sleeve can be better maintained. At the same time, some pressure equalization may be needed, at least in some applications, between the inside and outside surfaces of the insulating sleeve (perhaps including internal voids of the sleeve). If a pressure equalization path is needed, care should be taken to keep the pressure equalization path(s) small enough to prevent ingress of flowing thermally conductive particles (e.g., metallic catalyst particles, fines and/or coke).
Some example embodiments of the additively manufactured thermal insulating sleeve liner have two solid shells sandwiching a concurrently formed additively manufactured infill pattern (i.e., manufactured by a conventional 3D printing process). The infill pattern may vary and may range from simple honeycomb structures to complex lattice structures depending on process requirements and parameters. The sleeve may have an open end, or the ends may be fused to make the sleeve airtight. In the case of an airtight sleeve, the infill pattern chamber voids may be vacuumed or pressurized.
Some example embodiments of the additively manufactured thermal insulating sleeve liner are non-encapsulated with variable patterns on the external sleeve surface that may be modified depending on the application.
Some example embodiments of the additively manufactured thermal insulating sleeve liner have a wear-resistant coating along the axial flow way.
Some example embodiments of the additively manufactured thermal insulating sleeve liner are trapped via a separate retaining cap or have an integral lip which in either case is welded to one end of the bore to be protected on the flow device (e.g., with spot welds or seal welds that can be easily broken when it is desired to remove/replace a previously installed insulating sleeve).
The example embodiments described herein offer several advantages. The additively manufactured (e.g., 3D printed) thermal insulating sleeve device is produced in one manufacturing step resulting in considerable savings. It requires little lead time as the design process is much shorter than other manufacturing methods. Validation of the parts can commence as soon as the part is printed. Since the device can be additively manufactured, unique and more complex structures can be made for the infill without interfering with sleeve integrity. Additionally, there is very little material wasted in an additive manufacturing process and a homogeneous density of the resulting insulating sleeve ensures a more evenly distributed sleeve strength.
To reduce the laborious procedure that would involve dis-assembly of the protected flow device during part replacement or planned plant maintenance, the present example embodiments are designed to be easily replaceable upon reaching the end of design life. Some embodiments include a ceramic coating applied to either the internal surface of the thermal insulating sleeve or to the internal surface of the flow device to reduce wear and tear of the sleeve. The replacing can be done by removing the flow device from the process and sliding the loosely fit sleeve out of the flow device bore (after light holding spot or seal welds are broken). Additionally, toughness of the material involved will ensure that the sleeve is more robust than in the past thus ensuring, among other things, less scrap and a potential for the sleeve material to be re-used.
The accompanying drawings depict various example embodiments for illustrative purposes but are not to be construed as limiting the scope of later appended claims.
In the accompanying drawings identical reference numerals may have been used to identify features which are identical or similar in function. The example embodiments demonstrate varied designs based on similar concepts to provide an overall view of example thermal insulating sleeve liner interactions with flow devices.
Complex lattice infill patterns 16 provide a longer and indirect path for thermal conduction while air (or other insulating material or vacuum) trapped in between the two shells due to interstices of the infill pattern 16 possesses poor thermal conduction properties leading to increased thermal insulation.
While some prior art thermally insulating sleeve liners have been shrink-fitted into tight engagement with the internal walls of the flow device, it is preferred to only loosely slip-fit the thermally insulating sleeve liner 10 or 20 within the internal bore walls of the flow device so as to provide additional thermal insulation between a hot corrosive and erosive high pressure flowing substance and the flow device structures. In some embodiments, having a loosely slip-fit is preferred in order to apply the ceramic coating on the internal wall of the flow device to avoid applying unnecessary tensile stresses on the ceramic coating.
In some embodiments, the inner surface (i.e., the surface that is in contact with the fluid flow) of the inner shell 12 of the thermal insulating sleeve is applied with a ceramic coating. The primarily increases the resistance of the sleeve against wear and corrosion caused by the product flowing through the valve. The methods for applying ceramic coating may encompass various techniques, including, for example, wipe-on application or spraying application. In some embodiments, the thickness may for example, be between 1 um and 500 um. The composition of the coating may comprise a blend of SiO2 and TiO2 constituents. In some embodiments, the ceramic coating is applied only to the inner surface of the sleeve liner.
When disposed about an axial flow passage within a flow device bore (e.g., as shown in
While
As those in the art should now appreciate, the general installation overview of
To establish some measure of efficiency for an example embodiment, a 3-dimensional finite element analysis using a transient thermal technique was conducted for a ball valve having a flanged end connector inside diameter of 2.3 inches and an outside diameter of 4.5 inches, subjected to extreme temperature and pressure cycles (e.g., cycles were from atmospheric pressure at ambient temperature to 2,030.5 psi at 752 F.). Three different configurations were used: the flow device without any thermal protective device; the flow device with the internal surface that interacts with the axial flow path coated with thermal and wear resistant materials (e.g., by directly applying the coating inside the bore of the flow device, without the addition of any sleeve); and the flow device with a thermal protective sleeve as shown in
Peak stress intensities in the end connectors was found to be 605 MPa for the flow device without any thermal protective technology, 511 MPa for the model with the thermal and wear-resistant coatings and 259 MPa for the model with a thermal protective sleeve of the type described herein. This translates to a design life of 1,800 cycles, 2,900 cycles and 40,000 cycles respectively from fatigue design curves using fatigue analysis based on American Society of Mechanical Engineers (ASME) criteria (i.e., ASME 2015 Boiler & Pressure Vessel Code Section II Part D and Section III A were used for the fatigue analysis). In example embodiments in which a ceramic coating is wiped-on it is expected that stress reduction of around 50% may be achieved.
Depending on the application, the interior surface of the example embodiments may be sprayed with a suitable wear-resistant coating as those in the art will appreciate. In some embodiments, a ceramic coating can be applied within the interior of the thermal sleeve primarily to increase its resistance against wear and corrosion caused by the product flowing through the valve. The methods for applying ceramic coating may encompass various techniques, including, for example, spraying or wipe-on application. The composition of the ceramic coating may comprise a blend of SiO2 and TiO2 constituents but is not limited thereto. For example, other ceramics such as alumina (Al2O3), zirconia (ZrO2), etc. could be also used in some embodiments.
The functionality of the example embodiments is not limited to any particular flow device as those in the art will appreciate.
Example thermal insulating sleeve liners for a fluid flow device provide a loosely-fit additively manufactured thermal protective sleeve disposed axially in bores of flow devices such valves and pipes. The sleeve may have variable designs depending on applications and may include, but are not limited to: (a) a sleeve made of an internal shell, an outer shell and an infill pattern; (b) a sleeve with radial ridges; (c) a sleeve that is ribbed axially—and wherein the infill lattice structures and exterior surface patterns may be modified to meet process parameters. Any of these examples may be lipped or capped depending on the preferred arrangement and/or weld. Moreover, in some embodiments, any of these examples may have a ceramic coating applied to the inner surface of the sleeve to increase its resistance against wear and corrosion caused by the product flowing through the valve and to improve thermal insulation properties of the sleeve. For example, in some embodiments, a ceramic coating is applied to the surface of the flow device 44 that faces the thermal insulating sleeve liner 12 (see
An example thermal insulating sleeve liner structure having an internal shell, an outer shell and fused ends may have an airtight vacuumed infill chamber.
An example flow device fitted with an example thermal insulating sleeve liner may have an internal shell, an outer shell an infill chamber there-between with fused ends and a pressure equilibrium hole there-through.
An example thermal insulating sleeve liner structure may have an internal shell, outer shell, a pressurized infill chamber and seal-welded ends.
An example thermal insulating sleeve liner structure may be made of a high nickel alloy.
An example thermal insulating sleeve liner structure may have a wear-resistant coating on its inner surface of an internal shell.
An example thermal insulating sleeve liner structure may use a securing cap which may or may not be of the same material as the body of the flow device to which it is welded within a bore of the flow device. Alternatively, the securing cap may be threaded for a threaded connection with the bore of a flow device.
An example thermal insulating sleeve liner structure may include an integral lip welded to a bore on the body of the protected flow device.
Example thermal insulating sleeve liner structures may have an internal surface (i.e., surface that is in contact with the flow product) applied with a ceramic coating to increase its resistance against wear and corrosion caused by the product flowing through the valve. The methods for applying the ceramic coating may encompass various techniques, including, for example, spraying or wipe-on application. The composition of the ceramic coating may comprise a blend of SiO2 and TiO2 constituents but is not limited thereto.
Minor adjustment could be necessary on the sleeve to protect the ceramic coating during installation such as adding chamfer and improving surface finish. If this is not enough, then, as you suggested, we may have to add a claim.
As previously mentioned, numerous different infill patterns are feasible for different applications (e.g., a honeycomb pattern, a corrugated infill similar to that used for cardboard boxes, bicycle wheel spokes, etc.). However for extreme temperature and pressures encountered by catalyst injection valves and connection pipes in ebullated bed hydro-processing ore refining applications, the infill pattern of
As will be appreciated from the
As will be appreciated from the
In the example embodiment of
Because the infill pattern 800 comprises oblique elongated support structures, the resulting obliquely disposed heat conduction paths between the inner and outer shells are lengthened thus increasing thermal insulating properties of the sleeve liner and improving its ability to provide thermal protection at higher temperatures. As will be noted, oblique elongated support structures are also found in the example embodiments of
Because the infill pattern 800 creates pyramidal support structures, the compression strength of the sleeve liner is improved so as to better withstand usage at higher pressures. Indeed, the example of
In the example of
As will be appreciated by those in the art, the lower stresses imposed with only 20% infill are a great improvement (while still not resulting in destructive damage to the sleeve liner, e.g., buckling)—thus permitting many more cycles of successful valve operation before expected failure of the sleeve liner. As will be appreciated, an only 20% infill pattern greatly reduces thermal conductivity between the inner and outer shells. It is possible that an even lower percentage infill can be used without failure (e.g., buckling) of the liner for some applications encountering lower pressures/temperatures. This may also be possible even for the very high pressures/temperatures encountered in ebullated bed hydro-processing applications. However prototype laboratory testing of an example embodiment with only 20% infill pattern has now been conducted successfully to demonstrate a 20% infill may be optimum.
As is apparent from
Currently available simulation test results demonstrate that it is possible for an airtight Inconel sleeve using a 20% infill pattern to operate at high pressures—while extending valve cycle life (as compared to approximately 1,800 cycles having no thermal liner sleeve) by more than 2,000% (e.g., up to 40,000 cycles). Prior Inconel thermal spray coatings only extended cycle life to approximately 2,900 cycles. In embodiments in which a ceramic coating is applied either to the internal surface of the thermal insulating sleeve liner or to the internal surface of the flow device before the sleeve is inserted, the additional ceramic coating will further enhance the valve's cycle life by diminishing thermal stress and offering additional protection against wear.
A desired infill pattern 3D data file can be created with conventional computer aided design software (e.g., CREO software designed by Parametric Technology Corporation or nTopology's “element pro” software or an ANSYS plug-in offered by Ansys, Inc.) and thereafter suitably processed to provide a stereo-lithography (STL) file suitable for use by a 3D printer. With currently available commercial 3D printing services, it is possible work with a commercially available 3D printing company to develop the desired STL file to be used by that commercial service to manufacture the liner sleeve under suitable contractual business provisions. Of course such 3D printing processes can also be performed in-house if the facilities are available.
As noted above, some sleeve liner examples have closed ends and others have open ends. In general, the open-ended sleeves are less likely to experience buckle failure due to unequal inside/outside sleeve pressurization experienced by closed sleeve designs-and such an open end facilitates extraction of any undesired metal powder at the end of the 3D printing processes. However, as also noted above, a closed end sleeve can be made resistant to buckling by adding a suitably small pressurization equalization hole (or holes) though at least one of the inner and outer sleeve shells. And, as also noted above, the size of the pressurization hole(s) should be small enough to prevent ingress of thermally conductive particles contained in the controlled process fluid flow passing through the sleeve liner in use.
It is presently believed that a 20% infill pattern provides the lowest percentage of infill that can be used without unduly compromising sleeve strength. As the FEA tests indicate, 50% and 80% result in higher stresses (i.e., less thermal shock protection) but also make the sleeve stronger. However a 20% infill pattern reduces stress by almost 300% (as compared to having a 100% infill or no sleeve)-while having now been shown by laboratory prototype testing to provide sufficient sleeve strength. Accordingly, it is presently believed that 20% infill pattern is the optimal percentage infill.
A main objective for the infill pattern is, like strutting beams supporting a roof, to use the fewest strutting beams that can carry the load. And, since heat conducts faster through solid metal, it is desired to create as much interstice space as possible between the outer and inner shells of the sleeve. For reasons noted above, it is currently believed that a 20% infill pattern is better than higher percentages while concurrently providing sufficient strength for high pressure operations.
In
The example thermal sleeve 1204 can be easily installed with a sliding slip or tight fit (e.g., 0.002 inch clearance) until, of course, the distal end 1206 of sleeve 1204 engages with the mated configured sealing surface 1208 at the distal end of the bore of pipe 1200. This facilitates both installation and removal of sleeve 1204. In embodiments in which a ceramic coating is applied to the internal surface of the flow device before the sleeve is inserted, sliding fit is preferable to avoid applying unnecessary tensile stresses on the ceramic coating.
Indeed, the proximal end 1214 of sleeve 1204 can include an internal “hook” configuration 1218 to permit engagement with a sleeve extraction tool when it becomes necessary or desirable to remove the sleeve (e.g., for replacement after substantial wear and tear). By dis-engaging the retaining spring clamp 1212 and the sealing washer 1210, the sleeve 1204 can be engaged at its proximal end (e.g., via the hooked internal configuration 1218) with an extraction tool permitting the sleeve to be easily pulled out for replacement/repair.
While it is ultimately desired to have a solid outer shell 1500, currently available 3D printing processes make an apertured outer shell more practical if closed ends (e.g., such as 1214 and 1206) are employed. This is because during some 3D printing processes for metals, a residue of fine metal powder remains in the printed 3D monolithic structure and needs to be extracted. While this fine metal dust is easily blown away with compressed air (or the like), there must be some provided space for ingress of the pressurized air and egress of the undesired residue of metal powder. In an open-ended embodiment (e.g., see
Accordingly, the apertured outer shell 1500 (with an aperture over each diamond shaped interstice within the infill pattern 1502) has been found practical when both ends are sealed against ingress of fluid flow between the sleeve 1204 and internal surface of pipe 1200. That is, because the sliding tight or slip fit clearance between sleeve 1204 and the internal bore of pipe 1200 is sealed against ingress of fluid flows, it is permissible for the outer shell 1500 to have apertures. However, of course, the inner shell of sleeve 1204 needs to be solid (or to have only a very small pressure equalization hole sized to prevent ingress of solids in the fluid flow that would be adverse to thermal protection desirably provided by sleeve 1204.
Using different 3D metal printing processes it may be possible to avoid the need for extraction of a powered metal residue. Alternatively, it may be desired to fill the outer shell apertures and/or to cover then with a layer of solid metal. This would result in a non-apertured outer shell. However avoiding apertures in the outer shell do not presently appear necessary.
The example sleeve of
An FEA simulation was also developed and compared with the experimental thermal transient data obtained by laboratory testing. This demonstrated a reduction of more than 70% of peak stress intensity when the thermal sleeve is used (with a possible error or perhaps 15%).
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
This is a continuation-in-part (CIP) application of co-pending U.S. application Ser. No. 17/030,760 filed on Sep. 24, 2020, which is a CIP application claims priority benefits under 35 USC § 120 to parent application PCT/IB2020/052256 (designating the US and thus a pending non-provisional US application pursuant to 35 USC § 363) filed Mar. 12, 2020 which also claims the benefit of grand-parent U.S. Provisional Patent Application No. 62/823,357, filed Mar. 25, 2019. The entire contents of U.S. application Ser. No. 17/030,760, PCT Application No. PCT/IB2020/052256, and U.S. Provisional Patent Application No. 62/823,357 are herein and hereby incorporated by reference.
Number | Date | Country | |
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62823357 | Mar 2019 | US |
Number | Date | Country | |
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Parent | 17030760 | Sep 2020 | US |
Child | 18442394 | US | |
Parent | PCT/IB2020/052256 | Mar 2020 | WO |
Child | 17030760 | US |