Abstract: An apparatus and process for classifying fine particles from a particulate material, such as toner and pigment powders. The apparatus is generally a dynamic centrifugal gas (air) classifier that combines the operational advantages of centrifugal air classifiers with increased aerodynamic forces provided by a rotating member to classify powders at cutpoints of fifteen micrometers and finer. The classifier is configured to have an annular-shaped inner passage, an annular-shaped outer passage circumscribing the inner passage, and an inlet through which a gas-entrained particulate material is introduced substantially tangentially into the inner passage so as to impart a centrifugal force to the particulate material. A portion of the entraining gas is preferably separated and directed into the outer passage.

Abstract: An assembly that includes a CMC article, and a method of forming the assembly, so as to reduce the likelihood during a transient thermal condition of the CMC article becoming interlocked with the worn shank of a fastener used to secure the article to its support structure. The CMC article has oppositely-disposed first and second surfaces, a hole through the article and intersecting the first and second surfaces so as to define oppositely-disposed first and second openings at the first and second surfaces, respectively, and continuous chamfers along the entirety of the first and second openings. The assembly further includes a support structure adjacent the article, and a fastener received in the hole of the CMC article and securing the CMC article to the support structure. The location of the chamfers at the perimeter of each opening eliminates a relatively sharp edge that could interlock with the worn shank of the fastener during a thermal excursion.

Abstract: A seal assembly and method for a turbomachine having a rotary member and a stationary member circumscribing the rotary member. The seal assembly comprises an annular-shaped platform on the rotary member so as to be disposed at an outer circumferential region thereof. The platform is supported radially outward from the rotary member so as to project beyond axially-adjacent regions of the rotary member. The platform has a contact region radially separated from the rotary member by a cavity. A sealing member is disposed at a radially inward region of the stationary member, with a portion of the sealing member in rubbing contact with the contact region.

Abstract: A freestanding micrometer and method for determining the diameter of a cylindrical body, including measuring variations in diameter along a longitudinal length thereof, such as a roll used in the production of metal and paper sheet products. The micrometer comprises a housing supported on a circumferential surface of the cylindrical body. A first sensing element is movably supported by the housing and adapted for sensing a first surface point of the cylindrical body laterally spaced apart from the housing and disposed in a cross-sectional plane of the cylindrical body. A second sensing element is mounted to the housing for contact with a second surface point of the cylindrical body disposed in the cross-sectional plane of the cylindrical body. The first and second surface points locate, respectively, a terminal and midpoint of a chord lying in the cross-section plane of the cylindrical body, from which the diameter of the cylindrical body is determined.

Abstract: A coating system and method for reducing the tendency for hydrocarbon fluids, such as fuels and oils, to form carbonaceous deposits that adhere to the walls of a containment article. Of particular concern are carbonaceous deposits that form at temperatures below about 650° F. (about 345° C.). The coating system combines an outermost layer of platinum with a ceramic barrier layer. The coating system has been shown to significantly reduce the formation of carbonaceous deposits at temperatures between about 220° F. and 650° F. (about 105° C. to about 345° C.), as well as reduce the adhesion of such deposits. The platinum outermost layer also serves as a radiation shield to reduce heat transfer from the containment article to the hydrocarbon fluid. The outermost layer is preferably deposited as an extremely thin film by chemical vapor deposition. The barrier layer is deposited to a thickness sufficient to prevent interdiffusion of the platinum outermost layer with the containment wall.

Abstract: A thermal barrier coating, or TBC (26), and method for forming the TBC (26). The TBC (26) is formed of a thermal-insulating material that contains yttria-stabilized zirconia (YSZ) alloyed with at least a third oxide. The TBC (26) is formed to also contain elemental carbon, and may potentially contain carbides and/or a carbon-containing gas that forms from the thermal decomposition of carbon. The TBC (26) is characterized by lower density and thermal conductivity, high temperature stability and improved mechanical properties. To exhibit the desired effect, the third oxide is more particularly one that increases the lattice strain energy of the TBC microstructure as a result of having an ion size that is sufficiently different than a zirconium ion.

Abstract: A process of using sodium carbonate and sodium bicarbonate solutions to remove SO3 and other acidic gases or vapors from a flue gas without substantially decreasing the amount of sulfur dioxide also present in the flue gas. Very limited quantities of such solutions are injected into the flue gas in a manner that achieves a controlled droplet size, such that the solution dries on contact with the flue gas and the resulting dry particles of sodium carbonate/bicarbonate are sufficiently small as to have adequate surface area for reacting with SO3, as well as any H2SO4 and, to some extent, HCl vapors in the flue gas.

Abstract: An electrical machine stator core and method for reducing electromagnetic losses and the consequent heating of the core. The stator core makes use of laminations made from an iron-aluminum alloy at the core-ends of the core, while laminations between the core-ends are formed of a ferromagnetic alloy different from the iron-aluminum alloy. Use of iron-aluminum alloy laminations at the core-ends makes possible a relatively simple technique for generator uprate, by removing laminations located at the core-ends of the stator core, and then installing replacement laminations formed of the iron-aluminum alloy at the core-end, again with the result that the laminations located at the core-ends are formed of an Fe—Al alloy that is different from the alloy of the laminations between the core ends.

Abstract: A process for passivating the semiconductor-dielectric interface of a MOS structure to reduce the interface state density to a very low level. A particular example is a MOSFET having a tungsten electrode that in the past has prevented passivation of the underlying semiconductor-dielectric interface to an extent sufficient to reduce the interface state density to less than 5×1010/cm2−eV. Though substantially impervious to molecular hydrogen, thin tungsten layers are shown to be pervious to atomic hydrogen, enabling atomic hydrogen to be diffused through a tungsten electrode into an underlying semiconductor-dielectric interface.

Abstract: Method and apparatus for repairing an article, such as an air-cooled component, during which at least a portion of the component must be removed and replaced. The method and apparatus make use of one or more workpiece holders adapted to secure and position an component on the apparatus, a multi-axis head adapted for movement relative to the workpiece holder, a nozzle mounted to the multi-axis head and operable to remove at least a portion of the component with a jet of fluid discharged therefrom, an electrical-discharge electrode mounted to the multi-axis head and operable to form surface holes in the component by electrical-discharge machining, and a system for controlling the movement of the multi-axis head so that the waterjet and electrical-discharge machining operations are performed to yield a repaired component that closely duplicates the original.

Abstract: A process for depositing a ceramic coating on a component. The process involves a technique for evaporating an evaporation source containing multiple different oxide compounds, at least one of the oxide compounds having a vapor pressure that is higher than the remaining oxide compounds, to deposit a coating of the multiple oxide compounds. A high energy beam is projected onto the evaporation source to melt and form a vapor cloud of the oxide compounds of the evaporation source, while preventing the vapor cloud from contacting and condensing on the component during an initial phase in which the relative amount of the one oxide compound in the vapor cloud is greater than its relative amount in the evaporation source. During a subsequent phase in which the relative amount of the one oxide compound in the vapor cloud has decreased to something approximately equal to its relative amount in the evaporation source, the vapor cloud is allowed to contact and condense on the component to form the coating.

Abstract: A process of depositing a coating system suitable for use as an environmental barrier coating on various substrate materials, particularly those containing silicon and intended for high temperature applications such as the hostile thermal environment of a gas turbine engine. The process comprises depositing a first coating layer containing mullite, and preferably a second coating layer of an alkaline earth aluminosilicate, such as barium-strontium-aluminosilicate (BSAS), by thermal spraying while maintaining the substrate at a temperature of 800° C. or less, preferably 500° C. or less, by which a substantially crack-free coating system is produced with desirable mechanical integrity.

Abstract: A screen unit for removing solid particles from a viscous mass, for example molten plastic. The screen unit includes a housing provided with a supply channel and a discharge channel for the viscous mass, a screen element in the housing between the supply channel and discharge channel, a backflush channel for discharging during backflushing solid particles screened by the screen element and connected to an outflow channel by a shutoff valve, and a pressure element which can be operated to flush back the viscous mass through the screen element at a pressure higher than the pressure in the supply channel. The shutter element is placed along the screen element, and the shutter element is caused to move with respect to the screen element such that during the screening phase the screen element is gradually more exposed for screening and during the backflushing phase the screen element is gradually less exposed to the backflushing action.

Abstract: A method of operating an EBPVD apparatus (10) to deposit a ceramic coating on an article (20), such that the thermal conductivity of the coating is both minimized and stabilized. More particularly, the EBPVD apparatus (10) is operated to perform multiple successive coating operations which together constitute a coating campaign. During the campaign, the surface temperatures of the articles (20) being coated do not exceed about 1000° C. as a result of the combined heat transfer from the coating chamber (14) to the articles (20) being reduced during the course of the campaign, even though the temperature within the coating chamber (14) continuously rises during successive coating operations of the campaign. Ceramic coatings deposited at such relatively low temperatures exhibit lower and more stable thermal conductivities.

Abstract: An apparatus and process for removing acidic gases and NOx from flue gases produced by utility and industrial plants. The process and apparatus convert NOx, and particularly nitric oxide, to nitrogen dioxide, which is then reacted to form a valuable byproduct. The process generally entails contacting a flue gas with a scrubbing medium to absorb acidic gases from flue gas and produce an intermediate flue gas. The intermediate flue gas is then cooled to cause nitric oxide present therein to be oxidized to form nitrogen dioxide, which is then absorbed from the flue gases to produce a nitrogen dioxide-containing solution and a scrubbed flue gas. The nitrogen dioxide in the nitrogen dioxide-containing solution is then reacted with ammonium hydroxide to form ammonium nitrate as a valuable byproduct.

Abstract: A method of removing a ceramic coating, such as a thermal barrier coating (TBC) of yttria-stabilized zirconia (YSZ), from the surface of a component, such as a gas turbine engine component. The method generally entails subjecting the ceramic coating to an aqueous solution of ammonium bifluoride, optionally containing a wetting agent, such as by immersing the component in the solution while maintained at an elevated temperature. Using the method of the invention, a ceramic coating can be completely removed from the component and any cooling holes, with essentially no degradation of the bond coat.

Abstract: A cutting tool (10) adapted to produce chamfers along the edges of drywall panels. The tool (10,110,210) comprises a housing having a channel (18) defined by a base wall (13) and substantially parallel first and second sidewalls (15,17) that are substantially perpendicular to the base wall (13). A primary cutting blade (30) extends from the first sidewall (15) at an angle across the channel (18) toward the second sidewall (17). The primary blade (30) is configured to cut through an edge of a panel placed in the channel (18) as the cutting tool (10,110,210) is caused to move along the edge of the panel, thereby creating a chamfered edge on the panel. A second cutting blade (32) also extends from the first sidewall (15) and is positioned adjacent the primary blade (30) to create a perforation in the edge of the panel prior to the panel encountering the primary blade (30).

Abstract: A stainless steel alloy that exhibits both high strength and toughness as a result of having particular ranges for chemistry, tempering temperatures and grain size. The alloy is a precipitation-hardened martensitic stainless steel with an ultimate tensile strength of at least 1200 MPa, a Charpy impact toughness of greater than 55 J, and a grain size of ASTM 5 or finer. The alloy consists essentially of, by weight, 14.0 to 16.0 percent chromium, 6.0 to 7.0 percent nickel, 1.25 to 1.75 percent copper, 0.5 to 1.0 percent molybdenum, 0.03 to 0.5 percent carbon, niobium in an amount by weight of ten to twenty times greater than carbon, the balance iron, minor alloying constituents and impurities.

Abstract: An outdoor shelter comprising a sheet member (10) having a generally rectangular-shaped portion and a slit (26) extending from a first corner (62) of the sheet member (10) to the central region (50) of the sheet member (10). The slit (26) defines separated opposing edges, which are equipped with complementary means (30,32) for selectively securing the edges together. The edges define a first fold line (41) when secured together by the securing means (30,32). A third securing means (38) is disposed on a second fold line (42) extending from the central region (50) to a second corner (68) of the sheet member (10) adjacent the first corner (62). The third securing means (38) is complementary to the securing means (32) to enable the second fold line (42) to be secured to one of the edges of the slit (26). By selectively securing the securing means (30,32) to each other or the third securing means (38), the sheet member (10) can be configured to achieve a variety of shelter configurations.

Abstract: A castable and weldable nickel-base alloy that exhibits a desirable balance of strength and resistance to corrosion and oxidation suitable for gas turbine engine applications. A suitable composition for the alloy consists essentially of, by weight, 10% to 25% cobalt, 20% to 28% chromium, 1% to 3% tungsten, 0.5% to 1.5% aluminum, 1.5% to 2.8% titanium, 0.8% to 1.45% columbium, tantalum in an amount less than columbium and Cb+0.508Ta is 1.15% to 1.45%, 0.001% to 0.025% boron, up to 0.4% zirconium, 0.02% to 0.15% carbon, with the balance essentially nickel and incidental impurities.