Showing papers by "Rolls-Royce Limited published in 1960"

Axial flow compressor

Abstract: An axial flow compressor comprises a rotor having a plurality of axially spaced rings of rotor blades, a respective ring of stator blades being disposed immediately downstream of each ring of rotor blades, respective shroud surfaces being provided at the radially inner ends of the working surfaces of the stator blades by respective shroud rings carried by the rings of stator blades, running clearances being provided between the shroud rings and the rotor, and means whereby in operation a static pressure gradient is maintained in the clearance between at least one shroud ring and the rotor so that gas flow through the clearance is in a downstream direction.

Improvements in or relating to the heat treatment carburizing or welding of metals

Abstract: The formation of scale is reduced during the heat treatment of metals, such as ferrous metals, titanium or zirconium or alloys thereof, and nickel base alloys, by coating them with one or more layers of a sprayable mixture of an organophilic cation-modified clay and an organic solvent, such as toluene, xylene, naphtha, white or methylated spirit, benzene, aliphatic hydrocarbons, alcohols, esters or ketones, dipentene, turpentine or mineral oils, with or without a ceramic frit such as powdered glass or ceramics containing zircon or lead, a binder such as a polyester, polyamide, alkyd or silicone resin, dibutyl phthalate or shellac, and/or a filler such as china clay, water ground nepheline syenite or quartz, prior to heating in an atmosphere containing free oxygen at a temperature of at least 600 DEG C. Also, for carburizing ferrous metals using a carburizing atmosphere, e.g. of isopropanol and methane, at a temperature of at least 600 DEG C., the metal surfaces to be protected are coated beforehand with one or more layers of the above mixture. Similarly, the above mixture may be used as a flux for arc-welding ferrous metals (see Division B3). Each layer may be applied by spraying, brushing or dipping, and then drying. The clay is modified by covering the surfaces of the particles with alkyl or aryl radicals coupled to the clay ionically by an onium base as described in Specifications 664,830 and 782,724 and U.S.A. Specification 2,531,440. The bentonite group of clays are suitable for modifying. Examples of the modified clays are dimethyldioctadecyl ammonium montmorillonite or hectorite, and dodecylamine montmorillonite. The metal surfaces to be coated may first be degreased by washing with paraffin and treating with trichlorethylene vapour to remove organic material; paint may be removed with methylene chloride, and heavy scale by abrasive cleaning. After heat treatment any scale may be removed by wet blasting with water or sand blasting followed by immersion in HCl for stainless steel, or by immersion in nitric acid and calcium fluoride bath for titanium and its alloys, e.g. 2% Cu, up to 0.1% C, up to 0.01% H, up to 0.2% Fe, balance Ti. A zirconium alloy is disclosed of composition 1.5% Sn, 0.12% Fe, 0.05% Ni, 0.1% Cr. balance Zr.ALSO:The formation of scale is reduced during the heat treatment of metals, such as ferrous metals, titanium or zirconium or alloys thereof, and nickel base alloys, by coating them with one or more layers of a sprayable mixture of an organophilic cation-modified clay and an organic solvent, such as toluene, xylene, naphtha, white or methylated spirit, benzene, aliphatic hydrocarbons, alcohols, esters or ketones, dipentene, turpentine or mineral oils, with or without a ceramic frit such as powdered glass or ceramics containing zircon or lead, a binder such as a polyester, polyamide, alkyd or silicone resin, dibutyl phthalate or shellac, and/or a filler such as china clay, water ground nepheline syenite or quartz, prior to heating in an atmosphere containing free oxygen at a temperature of at least 600 DEG C. Also, for carburizing ferrous metals using a carburizing atmosphere, e.g. of isopropanol and methane, at a temperature of at least 600 DEG C., the metal surfaces to be protected are coated beforehand with one or more layers of the above mixture. Each layer may be applied by spraying, brushing or dipping, and then drying. The clay is modified by covering the surfaces of the particles with alkyl or aryl radicals coupled to the clay ionically by an onium base as described in Specifications 664,830 and 782,724 and U.S.A. Specification 2,531,440. The bentonite group of clays are suitable for modifying. Examples of the modified clays are dimethyldioctadecyl ammonium montmorillonite or hectorite, and dodecylamine montmorillonite. The metal surfaces to be coated may first be degreased by washing with paraffin and treating with trichlorethylene vapour to remove organic material; paint may be removed with methylene chloride, and heavy scale by abrasive cleaning. After heat treatment any scale may be removed by wet blasting with water or sand blasting followed by immersion in HCl for stainless steel, or by immersion in nitric acid and calcium fluoride bath for titanium and its alloys.

2 – chemical analysis in combustion chamber development

Abstract: Publisher Summary The development of combustion chambers for the aero-gas turbine is a complex problem. The ultimate objective is a combustion chamber, which burns hydrocarbon fuel in the minimum space, with the minimum weight of equipment and at a specific air flow with the minimum pressure drop. Combustion must be stable over a wide range of air-fuel ratios, so that sudden changes in throttle setting do not extinguish the flame. The energy released by combustion of the fuel is taken from the hot combustion gases by a turbine. It is difficult to obtain an even distribution of temperature at the turbine plane and the maximum temperature must be kept as low as possible. The walls of the flame-tube have to be maintained reasonably cool to ensure a good working life. With so many criteria to meet, the development of a combustion chamber is a lengthy business, made difficult by the fact that some factors are mutually incompatible, and the best compromise has to be obtained. Experimentation might be carried out at various levels of complexity. The ultimate stage is engine testing, which is costly. Where possible, the combustion system is broken down into small units, which might be development tested using a high pressure compressed air supply.