Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
  • B32B15/018—Layered products comprising a layer of metal all layers being exclusively metallic one layer being formed of a noble metal or a noble metal alloy
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
  • F01D11/02—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
  • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
  • F01D11/12—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part
  • F01D11/122—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part with erodable or abradable material
  • F01D11/125—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part with erodable or abradable material with a reinforcing structure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
  • F01D5/288—Protective coatings for blades
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12424—Mass of only fibers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12444—Embodying fibers interengaged or between layers [e.g., paper, etc.]

Definitions

• the invention relates to an inlet lining for labyrinth seals of a turbomachine, in particular a gas turbine made of a layered composite material with a core and a shell and inclusions, and a method for producing the inlet lining.
• Inlet linings for turbomachines are known from EP-OS 0 166940.
• the inlet linings disclosed there are intended to keep the radial gap between the rotor blades and the housing as small as possible.
• inlet linings for labyrinth seals are not made from a core material made of graphite or ceramic, as disclosed in EP-OS 0 165 940, but from better heat-dissipating metal felt or metal fabric without coverings or
• the object of the invention is to provide a generic inlet covering with improved start-up and grinding properties, in which an exothermic reaction is contained and the heat conduction properties are improved.
• the core consists of a matted or three-dimensionally cross-linked fiber body made of iron, nickel or cobalt-based alloys and the shell consists of one or more noble metals or noble metal alloys and each metal core is surrounded by the shell material and the inclusions consist of oxidation-resistant sliding materials from the group of oxides, carbides or nitrides with a hexagonal crystal lattice structure.
• This solution has the advantage that the core is made of an iron,
• Nickel or cobalt alloy provides the necessary strength to form a true-to-life inlet coating.
• the precious metal shell has a higher oxidation resistance than the dimensionally stable core material and limits and prevents the spread of an exothermic reaction through the oxidation-resistant barrier layer.
• the fiber body locally glows and partially also melts, so that the seal grinds in, but an explosive expansion of the combustion is prevented.
• the noble metal shell increases the heat dissipation, since noble metals show a higher heat conduction due to their higher electron mobility than base metals. In the case of conventional fillings, deposits have for
• Buckets have the task of grinding in the metal tips and therefore consist of corundum or other hard abrasive particles. In the case of labyrinth seals, such grinding particles would work off the metallic tips of the labyrinth seals and increase the leakage rate.
• the inclusions according to the invention made of oxidation-resistant sliding materials from the group of oxides, carbides or nitrides with a hexagonal crystal lattice layer structure have the advantage that the hexagonal crystal lattice layers, because they are not packs with the highest hexagonal density, can slide and thus do not subject the tips of the labyrinth seals to abrasive stress.
• the fiber body consists of metal wire, fibers or chips. Depending on the type of networking, these can be short or long. Depending on the fiber shape and type of fiber, different manufacturing processes are advantageous for forming a fiber body used. From endless drawn fibers of approx. 1 to 50 ⁇ m
• Diameters can be two-dimensional cross! agengewiekelte cylindrical layers, which are then cross-linked by diffusion contact sintering or diffusion annealing at the intersection of the fiber winding to form a fiber body.
• the endless drawn fibers are also suitable for producing needle felts or for forming three-dimensional knitted fabrics, knitted fabrics or fabrics.
• Long and short fiber chips can be processed into needle felt, which is particularly suitable for three-dimensional crosslinking by means of diffusion contact sintering or diffusion annealing to form a fiber body.
• Metal fibers, threads or wires, which have been galvanically deposited on cotton or carbon fibers, can be processed like fiber chips to form fiber bodies.
• Iron or iron-based alloys, nickel or nickel-based alloys or cobalt or cobalt-based alloys are used as the material for metal wires and fibers or chips.
• a major advantage of metal wire, fibers or chips is that the fiber body has a large initial porosity, so that a large pore volume is available for embedding.
• the fiber body has flat knitted, knitted, woven, knotted or wound, two-dimensional fiber layers which are cross-linked in the third dimension by diffusion contact sintering or diffusion annealing or by knitting, crocheting, quilting or sewing.
• This has the advantage that the fiber body does not affect in layers when grinding in the labyrinth tips can be worn so that no large foreign particles peel off when entering and can thus impair the function of an engine.
• Platinum, rhodium, gold or alloys of these elements are preferably used as the noble metal for the shell of the fiber core.
• These oxidation-resistant and heat-conducting metals have the advantage that they can be introduced very uniformly and inexpensively into the fiber body for sheathing the metal wires, fibers or chips.
• a preferred embedding consists of particles made of hexagonal boron nitride.
• the hexagonal boron nitride additionally improves the rubbing and rubbing behavior if it is introduced as an insert in the inlet lining before, during or after the shaping of the inlet lining.
• Pyrolytically deposited ⁇ -boron nitride has a hexagonal crystal lattice structure and is not only extremely resistant to oxidation, but also has a coefficient of friction such as graphite. It does not react with most molten metals and is not wetted and is as soft as talc.
• the object of specifying a method for producing the generic run-in covering is achieved in that the core material is first coated with one or more precious metals or their alloys, then the gaps or pores of the fiber body in whole or in part with a Bearings are filled so that a raw fiber body is formed, which is then processed into an inlet covering blank and finally pressed into an inlet covering.
• This sequence of process steps has the advantage that, until the completion of the run-in covering, quality-assuring intermediate products such as a coated core material after a precious metal coating step, a raw fiber body after a placement process for storage, a run-in covering blank after a processing and shaping step and finally after a pressing process, the run-in covering are manufactured.
• Each intermediate product can be subjected to its own quality inspection in order to advantageously ensure the quality of the end product.
• this method enables the completeness of the encapsulation of the core material and the thickness of the precious metal encapsulation to be determined. After the storage of sliding materials, the degree of filling of the pores and the remaining pore volume can be checked on the raw fiber body.
• the dimensional accuracy of the inlet covering blank can be measured and the shrinkage dimension for a compression step can be determined by pressing, thus ensuring the dimensional accuracy of the inlet covering.
• a reworking of the compressed inlet covering is also possible after a quality assurance step.
• the production has the further advantage that it is extremely economical, since commercially available qualities, such as those shown in Table 1 with trade names and chemical composition, can be used as the core material and are refined by means of the process according to the invention. TABLE 1
• a further preferred implementation of the method consists in first processing the core material to form an uncoated raw fiber body and then compressing or diffusion-bonding it to a run-in covering blank, and then noble metal coating is carried out by means of galvanic, CVD or plasma deposition and finally deposits are introduced.
• This process sequence has the advantage that a relatively compact raw fiber body already exists before the noble metal coating, the large number of fiber crossing points being fixed with the noble metal coating, as a result of which an improved 3-dimensional breaking strength is achieved.
• the grain size of the intercalation material is still small compared to the pore size of the compacted raw fiber body, so that a sufficient concentration of intercalation material can be achieved.
• impregnation of the fiber body with a slurry of particles of hexagonal boron nitride in a carrier liquid is preferably carried out after coating the core material with precious metals. After evaporation or air drying of the carrier liquid, hexagonal boron nitride particles remain in the pores of the fiber body.
• the resulting raw fiber body can then be processed into an inlet covering blank and finally compressed to an inlet covering by pressing.
• Example 1 describes an inlet coating made of metal wires with a rhodium coating and hexagonal boron nitride inclusions and its production.
• Example 2 describes a running-in covering and its manufacture from metal chips.
• Example 1 describes an inlet coating made of metal wires with a rhodium coating and hexagonal boron nitride inclusions and its production.
• a hose with a diameter of approx. 120 mm is knitted from an endless Hastelloy X wire (see Table 1). The hose is rolled up over a cylindrical auxiliary form until a raw seal is required volume for an enema has been reached. The raw seal volume is much larger than the end part of the finished inlet lining.
• the cylindrical blank is pre-compressed to almost twice the end part, whereby a three-dimensional diffusion crosslinking can be carried out simultaneously by diffusion contact sintering or diffusion annealing.
• the compacted raw part is pickled from the following chemicals in the following solution to remove impurities and oxide layers: a) approx. 300 ml HNO 3 with a concentration of 1.41 g / cm 3 b) approx. 35 ml HF with a concentration of 1.26 g / cm 3 c) approx.1,000 ml H 2 O.
• the blank is immersed in the above pickling solution, which is kept at approx. 50 oC, for approx. 30 s.
• the blank is then rinsed several times in hot water.
• the metal wires of the compacted blank are completely covered with rhodium.
• the compacted raw part is immersed in an electroplating bath of the following composition:
• a precious metal layer made of rhodium with a thickness of approx. 1 to 10 ⁇ m is formed on the Hastelloy X wire. After rinsing in hot water and hot air drying the coated fiber body, it is soldered onto a seal carrier.
• This coated blank is then processed into a run-in covering blank by introducing boron nitride particles.
• the raw part is soaked in a slurry of: a) 5 to 10% by volume hexagonal ⁇ -boron nitride b) 3 to 8% by weight inorganic silicate binder c) rest of distilled water and dried.
• the run-in pad blank is pressed into a final form into a run-in pad and dried at temperatures between 60 and 150 ° C.
• Example 2 describes an inlet coating and its production from metal chips.
• metal short fibers are machined from one of the materials in Table 1, felted and sintered under diffusion contact or diffusion annealing to a density of about 10 to 25% of the theoretical Density of the metal is pressed into a plate-shaped fiber body.
• This raw plate is pickled as in Example 1 and, after cleaning and drying, soaked and dried with an organometallic solution for the deposition of platinum or rhodium.
• a platinum or rhodium or platinum / rhodium coating of the fiber body separates from the organometallic compound by heating in several stages to 650 to 800 ° C.
• the precious metal-coated plates are cut and formed into fiber body blanks by bending, rolling, rolling or pressing and soldered into the gasket support parts. After the soldering, the fiber body blank is impregnated with a slurry of hexagonal boron nitride particles, as in Example 1, to form an inlet cover blank and finally a compression molding to the inlet cover.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
• Powder Metallurgy (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Looms (AREA)

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Applications Claiming Priority (2)

Publications (1)

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Citations (4)

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• 1991
  • 1991-09-18 DE DE4130946A patent/DE4130946C1/de not_active Expired - Lifetime
• 1992
  • 1992-08-08 CA CA002096435A patent/CA2096435A1/en not_active Abandoned
  • 1992-08-08 JP JP5505715A patent/JPH06505543A/ja active Pending
  • 1992-08-08 EP EP92916949A patent/EP0557474B1/de not_active Expired - Lifetime
  • 1992-08-08 US US08/064,149 patent/US5326647A/en not_active Expired - Fee Related
  • 1992-08-08 WO PCT/EP1992/001812 patent/WO1993006341A1/de not_active Ceased

Patent Citations (4)

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