Patent Description:
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 <NUM> °F and <NUM>,<NUM> psi at <NUM>-<NUM> 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 -<NUM> °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. 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: <CIT>; <CIT>; <CIT>; and <CIT>.

<CIT> discloses a reinforced pipe comprised of an outer pipe concentrically positioned over an inner pipe with a honeycomb of reinforcing material in between.

The present document describes an improved thermal insulating sleeve liner constructed of a suitable material for the serviced application (e.g., Inconel <NUM>® 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.

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 <NUM> 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.

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 <NUM> - <NUM> 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. This 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.

<FIG> is a schematic isometric general overview of a thermal insulating sleeve <NUM> having an inner shell <NUM>, outer shell <NUM>, an infill pattern <NUM> of supporting structure with included voids provided between the inner and outer shells <NUM>, <NUM>, and open ends <NUM> (e.g., see <FIG>). The material and infill pattern <NUM> of the thermal sleeve can be varied to offer different strengths and thermal insulation depending on the application for which it is intended. As those in the art will appreciate, a typical ebullated bed hydro-processing application flow device conveys a corrosive liquid carrying small (e.g., <NUM> - <NUM> diameter) catalyst particles at temperatures on the order of <NUM> - <NUM>,<NUM> °F at a pressure on the order of <NUM>,<NUM> psi. In this application, as those in the art will appreciate, a thermal insulating sleeve liner could typically be made of high temperature alloy (e.g. nickel alloy). As those in the art will recognize, the material and structure of the thermal insulating sleeve liner must be chosen appropriately in accordance with conventional standard design practices to accommodate process parameters of the application being serviced. Such sleeve characteristics are typically determined by the extreme pressures and temperatures to which the sleeve will be subjected. The thermally insulating sleeve liner <NUM> can be slip-fit into a flow device bore. The open ends <NUM> should be fitted to mating internal surfaces of the flow device sufficiently closely to make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) within the chamber of the infill pattern <NUM> or between the outer shell <NUM> and the inner surfaces of the flow device.

Complex lattice infill patterns <NUM> 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 <NUM> possesses poor thermal conduction properties leading to increased thermal insulation.

<FIG> is a schematic isometric general overview of a thermal insulating sleeve <NUM> having an inner shell <NUM>, outer shell <NUM>, an infill pattern <NUM> of supporting structure with included interstice voids provided between the inner and outer shells <NUM>, <NUM>, and fused ends <NUM> (i.e., closed ends <NUM> as depicted in <FIG> so as to encapsulate the voids included within the infill structure <NUM> between shells <NUM>, <NUM> and ends <NUM>). As with the thermal sleeve <NUM> of <FIG>, the material and infill pattern <NUM> of the thermal sleeve <NUM> can be varied to offer different strengths and thermal insulation depending on the application for which it is intended. Here the voids within the chamber containing infill pattern <NUM> can be vacuumed or pressurized before ends <NUM> are fused shut (e.g., one end can be left partially open and connected to a source of vacuum or pressurized thermally insulating gas or liquid fluid before this partial opening is also fused to a fully closed configuration). Once the voids are thus suitably treated and the ends <NUM> fused to a closed state, the thermally insulating sleeve liner <NUM> can be slip-fit into a flow device bore. The fused closed ends <NUM> make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) within the chamber of the infill pattern <NUM>. The fused ends <NUM> should be fitted to mating internal surfaces of the flow device sufficiently closely to make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) between the outer shell <NUM> and the inner surfaces of the flow device.

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 <NUM> or <NUM> 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.

<FIG> depict the example thermal insulating sleeves <NUM> and <NUM>, respectively, with an included securing cap or lip <NUM> at one end. A securing cap may be separately constructed and fitted at an end of the sleeve when installed within a flow device to secure it at a proper location in use within a flow device. A securing lip may be constructed as an integral part of the sleeve at an end to secure it at a proper location in use within a flow device.

<FIG> depicts an example capped radially-ribbed thermally insulating sleeve liner <NUM>. The externally extending interstices between ribs <NUM> will provide additional thermally insulating spaces when fitted within the internal surfaces of a flow device bore. Example sleeve liner <NUM> is preferably created by additive manufacturing (i.e., 3D printing) to provide a central portion of the sleeve body between inner and outer shells with an infill pattern as in the examples of <FIG>, <FIG> to provide still further thermal insulation as in these earlier-described embodiments. The section cut highlights an end contact between the sleeve <NUM> and a separate securing cap <NUM> (which functions, like the securing cap of earlier-described embodiments). As those in the art will recognize, the securing cap <NUM> could be replaced by an integrally manufactured securing/locating lip if desired (as depicted in <FIG>).

<FIG> depicts an example lipped axially-ribbed thermally insulating sleeve liner <NUM>. The externally extending interstices between ribs <NUM> provide thermally insulating spaces when fitted within the internal surfaces of a flow device bore. Example sleeve liner <NUM> is preferably created by additive manufacturing (i.e., 3D printing) to provide a central portion of the sleeve body between inner and outer shells with an infill pattern as in the examples of <FIG>, <FIG> to provide still further thermal insulation as in these earlier-described embodiments. The section cut highlights the integrally formed securing/locating lip <NUM> formed at an end of the sleeve <NUM> (which functions, like the locating/securing lip of earlier-described embodiments). As those in the art will recognize, the locating/securing lip <NUM> could be replaced by a separate securing/locating cap if desired (as depicted in <FIG>).

When disposed about an axial flow passage within a flow device bore (e.g., as shown in <FIG>), the externally ribbed sleeve <NUM> or <NUM> makes less surface contact with the flow device bores due to the surface pattern of ribs on its exterior thereby reducing thermal stress concentration points.

While <FIG> illustrate two options of radially-ribbed and axially ribbed exterior surfaces, as those in the art will appreciate, the ribbed pattern can be modified as desired to accommodate requirements of various processes.

<FIG> and <NUM>-<NUM> depict a capped thermal protection sleeve <NUM> installed in a flow device <NUM>. The thermally insulating sleeve <NUM> (of any example embodiment described herein) can be disposed in a flow device (e.g., flanged pipe <NUM>) detachably connectable to other flow devices (e.g., valves). The interaction between the sleeve <NUM> and the pipe <NUM> is like that between an example sleeve and the internal flow surfaces of other flow devices (e.g., valves). The example thermally insulating sleeve <NUM> is slip-fitted into a bore of the pipe body that has a smaller diameter end portion locating and closing (if the sleeve does not already have a closed end) one end of the sleeve <NUM> to the ingress of flowing thermally conducting materials in use. A securing cap <NUM>, disposed within a larger diameter end portion of the flow device bore, secures and locates the other end of the thermal insulating sleeve <NUM> within the flow device bore (and closes it to ingress of flowing thermally conducting materials in use if the sleeve does not already have a closed end).

<FIG> depicts lipped thermal protective sleeves <NUM>, <NUM> slip fitted into flanged pipe input/output ports of a valve <NUM>. In an enlarged partial section view depicted at <FIG>, the outer surfaces of integral securing/locating lip <NUM> of sleeve <NUM> is mated to a larger diameter proximal internal bore section <NUM> while the main body of sleeve <NUM> is slip-fit into the relatively narrower main bore <NUM> of the flow device valve <NUM> - and the other end of sleeve <NUM> is butted to a narrower diameter distal bore section. The lip <NUM> is held in place during use by weld(s) <NUM> (e.g., spot or seal welds that can be easily broken when it is desired to remove/replace the sleeve <NUM>).

As those in the art should now appreciate, the general installation overview of <FIG> also can be used for a capped thermal protective sleeve (with open or fused ends and a separate locating/securing cap at the proximal end). As such, the arrangement of <FIG> can be used for all lipped or capped sleeve example embodiments. This includes the radially ribbed, axially ribbed, the in-filled lattice sleeves of <FIG>, <FIG> and so forth whether capped or lipped.

<FIG> illustrates capped thermal protective sleeves <NUM>, <NUM> slip fitted within the bores of a flow device (e.g., the flanged input/output pipes of a valve <NUM>). Like the lipped sleeve of <FIG>, this arrangement applies in general to all example thermally insulating sleeves. The sleeves <NUM>, <NUM> are fitted into the flow device <NUM> just like sleeves <NUM>, <NUM> are fitted into the flow device <NUM>. However, as depicted in the enlarged view at <FIG>, since a separate securing cap <NUM> is now employed (instead of the integral lip <NUM> in <FIG>), the securing cap <NUM> is held in place during use by weld(s) <NUM> (e.g., spot or seal welds that can be easily broken) while the distal other end of a sleeve is located against a smaller diameter bore section at the opposite distal end of the flow device bore (with a sufficiently small clearance fit to prevent ingress of thermally conductive material during use). This arrangement holds for all capped or lipped sleeve example embodiments. This includes the radially ribbed, axially ribbed, the in-filled lattice sleeves of <FIG>, <FIG> and so forth whether capped or lipped.

<FIG> is a cut-away schematic isometric view of valve <NUM> in <FIG> showing sleeve <NUM> having its distal end butted to a smaller diameter distal end <NUM> of flow device bore <NUM> and trapped there by the larger diameter cap <NUM> within larger diameter proximal bore <NUM> by weld(s) <NUM>.

To establish some measure of efficiency for an example embodiment, a <NUM>-dimensional finite element analysis using a transient thermal technique was conducted for a ball valve having a flanged end connector inside diameter of <NUM> inches and an outside diameter of <NUM> inches, subjected to extreme temperature and pressure cycles (e.g., cycles were from atmospheric pressure at ambient temperature to <NUM>,<NUM> psi at <NUM> 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; and the flow device with a thermal protective sleeve as shown in <FIG>. The thermal protective sleeve was made of Inconel <NUM>® by conventional 3D printing processes.

Peak stress intensities in the end connectors was found to be <NUM> MPa for the flow device without any thermal protective technology, <NUM> MPa for the model with the thermal and wear-resistant coatings and <NUM> MPa for the model with a thermal protective sleeve of the type described herein. This translates to a design life of <NUM>,<NUM> cycles, <NUM>,<NUM> cycles and <NUM>,<NUM> cycles respectively from fatigue design curves using fatigue analysis based on American Society of Mechanical Engineers (ASME) criteria (i.e., ASME <NUM> Boiler & Pressure Vessel Code Section II Part D and Section III A were used for the fatigue analysis).

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.

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.

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.

<FIG> is a 3D rendering of an example lattice infill <NUM> between inner sleeve <NUM> and outer sleeve <NUM>. This example embodiment is to be additively manufactured (e.g., by 3D printing) from Inconel <NUM>® metal and thus provide a unitary monolithic thermal insulating sleeve liner. As can be seen, the infill pattern <NUM> comprises tessellation of a basic infill pattern of four obliquely extending elongated solid cylindrical structures which mutually intersect mid-way between the inside surfaces of the inner and outer shells. As explained below, if the inner shell <NUM> and outer shell <NUM> are both solid, then an end is preferably left open (at least initially) so that any residue of metal powder can be extracted (e.g., before the end is closed, if desired, for completion of the manufacturing and/or installation process).

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 <FIG> can provide suitable protection.

As will be appreciated from the <FIG> depiction of one of the base lattice infill <NUM> pattern structures, four small solid cylinders (<NUM>, <NUM>, <NUM>, and <NUM>) mutually intersect with each other at <NUM> midway between the inside surfaces of the inner and outer shells <NUM>, <NUM> and extend along edges of a pair of right square pyramids having a common vertex (at the mutual intersection point <NUM>) pointed in opposite directions. That is, one of these pyramids has its vertex (opposite its square base formed by one of the liner shells) pointed "up" and the other of these pyramids has its vertex (opposite its square base formed by the other liner shell) pointed "down". This provides a strong compression resistant mutually cooperating pair of pyramidal supports between the inner and outer shells.

As will be appreciated from the <FIG> oblique partial cross-sectional depiction of a portion of the <FIG> sleeve liner, because the sleeve is manufactured by an additive process (e.g., 3D printing), the resulting liner shells and support structures (including the obliquely extending elongated support structure cylinders) are created as a single monolithic one-piece metal structure.

In the example embodiment of <FIG>, the volume of these small cylinders of the infill pattern <NUM> occupy only <NUM>% of the total volume encompassed by the internally opposite facing cylindrical walls of the inner and outer cylindrical shells <NUM>, <NUM>. This relatively sparse filling reduces thermal conductivity while also possibly permitting some degree of flexibility to responsively cope with abrupt beginning and ending of very high pressure fluid flows through the liner.

Because the infill pattern <NUM> 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 <FIG>, <FIG>, <FIG>, 3B4, 4A5, <FIG> and <FIG>.

Because the infill pattern <NUM> 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 <FIG> provides multiple mutually supporting pyramidal structures at each instance of the tessellated base support units shown in <FIG>.

In the example of <FIG>, the radial dimension between the inner shell <NUM> and outer shell <NUM> is desirably as much as can be accommodated for a particular application. For example, if the inner diameter of the flow device to be protected is on the order of <NUM> inches, a radial dimension on the order of <NUM> inch can be accommodated in some instances while a radial dimension on the order of <NUM> inch might be all that is needed or practical in other instances. The tessellated support structures are uniformly distributed within this inner space and dimensioned so as to occupy approximately <NUM>% of the volume between the inner and outer shells. The radial thickness of the outer shell <NUM> is less than that of the inner shell <NUM> so as to accommodate expected erosion of the inner shell when exposed to high pressure, high temperature, flow of highly corrosive catalyst flows (e.g., during catalyst injection for ebullated bed hydro-processing ore refining operations). For example, if the inner bore diameter of the flow device to be protected is on the order of <NUM> inches, the radial thickness of the outer shell <NUM> may be on the order of <NUM> inch in some instances while the radial thickness of the inner shell <NUM> may be on the order of <NUM> or <NUM> inch in other instances. As will be recognized, if the ratio of inner shell thickness to outer shell thickness is greater than one, substantial erosion of the inner shell <NUM> can be tolerated before replacement/refurbishment of the thermally protective sleeve is required. Preferably the thickness ratio is on the order of <NUM> or <NUM>.

<FIG> provides graphical results of an FEA (finite element analysis) stress analysis for simulated infill patterns occupying different percentages of the volume defined by inner surfaces of the inner and outer shells. The graphs depict equivalent/Von-Mises stresses (psi) at the inside diameter of a sleeve as a function of time (depicted in time units of seconds) caused by thermal expansion after a simulated abrupt valve operation exposing the liner to a step function of incoming fluid at expected high temperature and pressure (e.g., up to approximately <NUM>,<NUM> psi and <NUM> °F in an ebullated bed environment). Example thermally insulating sleeves as described herein are configured to operate in high pressure environments of at least <NUM>,<NUM> psi - and preferably much higher as in ebullated bed applications.

As will be appreciated by those in the art, the lower stresses imposed with only <NUM>% 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 <NUM>% 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 <NUM>% infill pattern has now been conducted successfully to demonstrate a <NUM>% infill may be optimum.

<FIG> provides a schematic partial cross section of an example sleeve liner having an overall axial length of <NUM> inches, an outside diameter of <NUM> inches, an inside diameter of <NUM> inches. As shown, the outer sleeve has a thickness of <NUM> inches while the inner sleeve has a thickness of <NUM> inches leaving an internal thickness of <NUM> inches for the desired integrally formed infill design.

<FIG> provides a schematic partial cross section of an example sleeve liner having the same dimensions as the example of <FIG> except for a slightly larger inside diameter of <NUM> inches and a slightly thinner inner shell thickness of <NUM> inches.

As is apparent from <FIG>, these example sleeve liners have different inner and outer shell thicknesses, the thicker inner shell being provided for accommodating expected erosion and corrosion of the inner shell during operations with fluid flow. Of course, as will be recognized by those in the art, the exact dimensions depicted in <FIG> examples may be suited as sleeve liners for a particular fluid flow device conduit (e.g., a ball valve inlet/outlet port). For other fluid flow devices different inside and outside diameters and axial lengths (as well as shell thicknesses) may be needed or desirable.

Currently available simulation test results demonstrate that it is possible for an airtight Inconel sleeve using a <NUM>% infill pattern to operate at high pressures - while extending valve cycle life (as compared to approximately <NUM>,<NUM> cycles having no thermal liner sleeve) by more than <NUM>,<NUM>% (e.g., up to <NUM>,<NUM> cycles). Prior Inconel thermal spray coatings only extended cycle life to approximately <NUM>,<NUM> cycles.

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 <NUM>% infill pattern provides the lowest percentage of infill that can be used without unduly compromising sleeve strength. As the FEA tests indicate, <NUM>% and <NUM>% result in higher stresses (i.e., less thermal shock protection) but also make the sleeve stronger. However a <NUM>% infill pattern reduces stress by almost <NUM>% (as compared to having a <NUM>% infill or no sleeve) - while having now been shown by laboratory prototype testing to provide sufficient sleeve strength. Accordingly, it is presently believed that <NUM>% 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 <NUM>% infill pattern is better than higher percentages while concurrently providing sufficient strength for high pressure operations.

In <FIG>, an input port flow passage pipe <NUM> is shown in cross section as connected conventionally to a ball valve body <NUM>. An example thermally protective sleeve <NUM> is shown in position for insertion (along the arrowed line) into the inside bore of pipe <NUM> where the distal sleeve end <NUM> is configured to sealingly mate with a configured distal internal surface <NUM> of the bore of pipe <NUM>. Also shown in <FIG> are sealing washer <NUM> and retaining spring clip <NUM> which, when installed against the proximal end <NUM> of sleeve <NUM> inside the bore of pipe <NUM>, are captured by the configured proximal internal surface <NUM> of the bore of pipe <NUM>. Thus, both the proximal and distal ends of sleeve <NUM> are sealed against entry of flowing fluid (or at least particles there-within that would adversely affect thermal sleeve protection) into the space between the outer shell of sleeve <NUM> and the internal surface of the bore of pipe <NUM>.

The example thermal sleeve <NUM> can be easily installed with a sliding slip or tight fit (e.g., <NUM> inch clearance) until, of course, the distal end <NUM> of sleeve <NUM> engages with the mated configured sealing surface <NUM> at the distal end of the bore of pipe <NUM>. This facilitates both installation and removal of sleeve <NUM>.

Indeed, the proximal end <NUM> of sleeve <NUM> can include an internal "hook" configuration <NUM> 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 <NUM> and the sealing washer <NUM>, the sleeve <NUM> can be engaged at its proximal end (e.g., via the hooked internal configuration <NUM>) with an extraction tool permitting the sleeve to be easily pulled out for replacement/repair.

<FIG> depicts the example sleeve of <FIG> installed within pipe <NUM>. 12A depicts an enlarged view of the proximal end of sleeve <NUM> with the sealing washer <NUM> and retaining spring clip <NUM> captured by the configured proximal end <NUM> of the bore of pipe <NUM>. 12B depicts an enlarged view of the distal end of sleeve <NUM> sealingly engaged at its configured end <NUM> with the configured internal sealing surface <NUM> of the bore of pipe <NUM>.

<FIG> depict three successive stages involved in extraction of sleeve <NUM> from pipe <NUM>. In <FIG>, sleeve <NUM> has been previously installed within pipe <NUM> but the retaining spring clip <NUM> and sealing ring <NUM> have now been removed (via conventional mechanical operations well known to those in the art). An extraction tool <NUM> having a resilient hooked distal end portion <NUM> (for engagement with internal hooked configuration <NUM> of sleeve <NUM>) is positioned for longitudinal movement (see arrow) into the sleeve <NUM>. In <FIG>, the extraction tool <NUM> has moved so that its resilient hooked distal end <NUM> has become engaged with the internal hooked configuration <NUM> of sleeve <NUM>. In <FIG>, the extraction tool <NUM> is next moved in the opposite longitudinal direction (see arrow) pulling with it the sleeve <NUM> so that it can be replaced/repaired.

<FIG> is a 3D rendering of the example sleeve <NUM> showing an apertured outer shell <NUM> with the previously described configured distal end <NUM> and proximal end <NUM>. A cut-away portion of the outer shell <NUM> reveals diamond-shaped walls to define infill pattern <NUM>.

While it is ultimately desired to have a solid outer shell <NUM>, currently available 3D printing processes make an apertured outer shell more practical if closed ends (e.g., such as <NUM> and <NUM>) 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 <FIG>, <FIG>) ingress of compressed air and egress of metal powder can be accommodated though the open end. However, when both ends are closed, some other arrangement is needed.

Accordingly, the apertured outer shell <NUM> (with an aperture over each diamond shaped interstice within the infill pattern <NUM>) has been found practical when both ends are sealed against ingress of fluid flow between the sleeve <NUM> and internal surface of pipe <NUM>. That is, because the sliding tight or slip fit clearance between sleeve <NUM> and the internal bore of pipe <NUM> is sealed against ingress of fluid flows, it is permissible for the outer shell <NUM> to have apertures. However, of course, the inner shell of sleeve <NUM> 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 <NUM>.

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.

<FIG> illustrate another example embodiment using an interference fit of solid bands at both ends and <NUM>% infill. The interference fit seals both ends <NUM> and <NUM> of thermal sleeve <NUM> to the internal bore of the protected pipe. As shown in more detail at the cross section of <FIG> and the enlarged segments of <FIG>, sections of the ends (e.g., section <NUM> of proximal end <NUM> and section <NUM> of distal end <NUM>) are machined for an interference fit within the bore of a protected pipe (e.g., inlet/outlet pipes of a ball valve). This means that in order to install sleeve <NUM> within the protected flow device bore, typically the temperature of the protected bore must be increased sufficiently (and/or the temperature of the sleeve must be decreased sufficiently) to temporarily increase the clearance to a non-interference condition - sufficiently to permit insertion of the interference fit machined sleeve <NUM>. If desired, a snap retaining spring can be used at the proximal end of the sleeve to prevent subsequent movement of the sleeve within the pipe bore during high temperature operation. After installation, the temperature of the protected flow device is permitted to equalize with that of the sleeve so that a true interference sealed fit is established at both ends of the sleeve. However, as will be appreciated, this embodiment will entail substantially more effort during both sleeve installation and removal.

<FIG> includes three side-by-side photographs of short length open ended thermal protective sleeve examples (e.g., see <FIG>, <FIG>) having <NUM>% infill, <NUM>% infill and <NUM>% infill (respectively when viewed from left to right). As will be noted, the tessellated supporting structures are obliquely oriented (in a righthand sense somewhat like the spokes of a bicycle wheel) between the inner and outer shells. These prototype examples were additively manufactured and tested to assess feasibility and validation of thermal protection and strength for these different infill pattern amounts. Such testing has shown the infill density of <NUM>% was more efficient in reducing thermal shock and peak stress intensity.

The example sleeve of <FIG> (i.e., interference fitted full size <NUM> inch long sleeve) was manufactured from Inconel <NUM>® metal by 3D printing (laser powder bed fusion 3D printing process) and laboratory tested to assess feasibility in reducing thermal stress induced by rapidly cycling temperature in isolation valves under laboratory-simulated Ebullated Bed application conditions. The test valve body was submitted to five rapid heating and cooling cycles, approximately the number of cycles per day that the sleeve may experience during actual Ebullated Bed use. Thermal shock results show the heating rate of the body ID is reduced more than about <NUM>% (compared to no sleeve).

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 <NUM>% of peak stress intensity when the thermal sleeve is used (with a possible error or perhaps <NUM>%).

Claim 1:
A monolithic metal thermal insulating sleeve liner configured for use in a high pressure fluid flow device subjected to cyclic extreme thermal shock, said configured thermal insulating sleeve liner comprising:
a monolithic hollow metal cylindrical sleeve (<NUM>) having two opposing spaced-apart ends (<NUM>) and an outer diameter sized to slide into a bore of a fluid flow device, said ends being configured to seal against fluid flow between an inner surface of the fluid flow device bore and the outer diameter of the sleeve between said ends, while accommodating a fluid flow path there-within along an inside bore of said sleeve, said sleeve including internal interstices providing increased thermal resistance to heat flowing from inside the sleeve to outside the sleeve;
said monolithic hollow metal cylindrical sleeve (<NUM>) comprising outer and inner shells (<NUM> and <NUM>) integrally formed with tessellated support structures (<NUM>) arrayed there-between, characterized in that
the metal is 3D printed nickel based alloy material.