A converter for converting an incoming alternating current (AC) electrical signal to an outgoing direct current (DC) electrical signal, comprising: a signal chopping module adapted to receive and chop the incoming AC electrical signal to generate a plurality of high voltage pulses having a substantially same amplitude at a given frequency; a transformer coupled to the signal chopping module and having multiple primary and secondary windings configured to reduce the voltage of the plurality of high voltage pulses and output a plurality of low voltage pulses; and a rectifying module coupled to the transformer and adapted to receive the low voltage pulses and generate therefrom the outgoing DC electrical signal.
H02M 7/04 - Conversion of AC power input into DC power output without possibility of reversal by static converters
H02M 7/06 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
H02M 7/155 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only
A method for boron introduction into a carbon anode of an electrolytic cell for the production of aluminium in order to improve the resistance of the anode to deterioration during the electrolysis process via the attack of air and of oxidizing gases released at the anode and which comprises: baking a green carbon anode in a baking furnace, the green carbon anode being at least partially surrounded by packing coke having a boron containing compound in order to obtain a prebaked carbon anode that includes boron.
The invention relates to a brazing metal sheet consisting of an aluminum alloy core sheet coated on at least one surface with a cladding layer forming a sacrificial anode, and is characterized in that said cladding layer consists of an aluminum alloy having a chemical composition, as expressed in weight percent, of: Si: > 2.0 – 7.0 Fe < 0.5 Cu < 1.0 Mn: 1.0 – 2.0 Mg < 0.5 Zn: 1.0 – 3.0 Cr < 0.25 Ni < 1.5 Ti < 0.25 Co < 1.5 V, In, Sn, Zr, Sc < 0.25 each; other elements < 0.05 each, and 0.15 total. The invention also relates to a heat exchanger tube produced by the bending and brazing of a brazing metal sheet, the sacrificial anode-forming cladding layer of which constitutes the inner coating of the tube, or the “inner liner”.
An extrudable aluminum alloy composition includes, in weight percent, between 0.60 and 0.90 manganese, between 0.45 and 0.75 copper, between 0.05 and 0.24 magnesium, less than 0.30 iron, less than 0.30 silicon, less than 0.05 titanium, less than 0.05 vanadium, and a Cu/Mg ratio higher or equal to 3. It also relates to aluminum alloy heat exchanger extruded or drawn tube and extruded or drawn aluminum alloy tubing having the above-described aluminum alloy composition. It also relates to a heat exchanger comprising a plurality of extruded or drawn tube sections having the above-described aluminum alloy composition and a process for manufacturing same.
B21D 39/06 - Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by platingTube expanders of tubes in openings, e.g. rolling-in
B21D 53/06 - Making other particular articles heat exchangers, e.g. radiators, condensers of metal tubes
The invention relates to a device (50) and a method for short-circuiting a specified electrolysis in a row of electrolysis cells intended for the production of aluminium. This device includes a bridging member (60) including at least two opposite contact arms and at least one bridging conductor electrically that electrically connects the contact arms. The contact arms are shaped like a wedge. The device further includes a clasping member (70) including a frame and a least two opposite thrust members. The clasping member (70) is fit to embrace the bridging member (60) so that each thrust member bears on each contact arm and so that, upon moving the contact arms with respect to the clasping member, each thrust member urges the corresponding contact arm towards the conductors (201, 202) inserted between the contact arms, so as to create and secure a short-circuit. The invention makes it possible to short-circuit electrolysis cells with increased amperages.
The subject of the invention is a carbon anode block for use in a metal electrolysis cell, of height H between an upper face (24) and a lower face (23), said block having, on the lower face (23), at least one groove (20a) of depth p(x) and length Lr, the groove extending along a direction x and said depth p(x) varying along said direction x, characterized in that said depth p(x) varies non-linearly along said direction x and in that said depth p(x) is smaller than a first value Z1 of at least 60% of the length Lr of said groove and is greater than a second value Z2, which is at least equal to Z1 + 10% of the height H, over 3 to 40% of the length Lr of the groove.
The invention relates to a multi-polar reduction cell for production of a light metal by electrolysis. The cell has an anode, a cathode, and at least one current-conducting multi-polar electrode interposed between the anode and the cathode. The cell has a molten electrolyte containing a metal salt to be electrolyzed held within the cell and preferably has means to maintain an upper surface of the electrolyte at a predetermined level within the cell. The level is preferably maintained above the upper end of the multi-polar electrode(s), at least in use of the cell. The multi-polar electrode has an electrically insulating surface at its upper end that minimizes or eliminates by-pass current between the anode and cathode when the cell is operated. The invention also relates to the method of minimizing or eliminating the by-pass current.
The invention relates to a process for decreasing adherence between a metallic surface and a molten metal or a semi-solid metal slurry, and to an adhesion decreasing metallic surface comprising a coating, the coating comprising a plasma-spray applied first layer on the metallic surface, wherein the first layer is a relatively smooth surface layer of a metal oxide. The invention further relates to a coating for use in decreasing the adherence of a molten metal to a metallic surface, the coating comprising: i) an underlying layer of a metal oxide; and ii) a second layer, atop of the underlying layer of metal oxide, comprising a powder material selected from the group consisting of boron nitride, mica or calcium silicate onto the layer of metal oxide.
C23C 4/10 - Oxides, borides, carbides, nitrides or silicidesMixtures thereof
B05D 1/04 - Processes for applying liquids or other fluent materials performed by spraying involving the use of an electrostatic field
B05D 5/08 - Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures to obtain an anti-friction or anti-adhesive surface
B22C 3/00 - Selection of compositions for coating the surfaces of moulds, cores, or patterns
B22D 17/00 - Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
C23C 24/00 - Coating starting from inorganic powder
C23C 24/08 - Coating starting from inorganic powder by application of heat or pressure and heat
The method of the invention provides means of destroying highly stable metal cyanide ions found in a solution, and converting the cyanide to harmless by-products. Contrary to conventional methods which merely complex the cyanide into a mechanically or physically removable complex, the present method destroys the cyanide found in the sample. The invention is directed to a method of destroying cyanide comprising providing a highly alkaline solution containing a metal cyanide ions; and subjecting the solution to electro-oxidation.
A deformable/inflatable wear liner (28) is attached to an inner surface of a wall (22) of a granular material delivery passage (20). Pressurized air may be introduced into a space between the wall (22) and the wear liner (28) to inflate the wear liner (28), thereby preventing solids from building up in the passage (20).
A belt tensioner comprises a belt (12) trained on a drive pulley (14) driven by a drive unit (18) mounted on a base (20) supported on air-spring bellows (28) linearly extendable under fluid pressure from a collapsed position to an extended position to cause joint movement of the base (20), the drive unit (18) and the drive pulley (14) and thereby change the tension in the belt (12). A pressure regulator (30) is operatively connected to the air-spring bellows (28) for regulating the fluid pressure in the air-spring bellows (28) such as to maintain the tension substantially constant in the belt (12) during use.
The invention relates to a method for transporting a powdery material by potential fluidisation, according to which a device is installed between the supply region and the region to be supplied, said device comprising at least one substantially horizontal conveyor (3), called 'aeroducting', which has a lower duct (6) for the circulation of a gas and an upper duct (7) for the circulation of the powdery material, the lower duct and the upper duct being separated by a porous gas-permeable wall (5). According to said method, the upper duct is filled with the powdery material and the lower duct is supplied with pressurised gas enabling the potential fluidisation of the powdery material in the upper duct provided with at least one pressure equalisation column (4.1, 4.2). The minimum bubbling speed corresponding to the maximum vacuum rate is determined in advance, and the fluidisation pressure is regulated to a value such that the fluidisation speed of the gas is between 0.8 and 1.5 the minimum bubbling speed, preferably between 0.9 and 1.3 times the minimum bubbling speed.
The present invention relates to modified alloy compositions for reduced hot tear susceptibility, where the aluminum alloy comprising from 0.01 to 0.025 % by weight of Sr; and TiB2, measured by its boron content, from 0.001 to 0.005% by weight of B. The invention also relates to method of preventing or eliminating hot tears in an aluminum alloy comprising the step of combining with aluminum from 0.01to 0.025 % by weight of Sr; and TiB2, measured by its boron content, from 0.001 to 0.005% by weight of B.
C22C 21/08 - Alloys based on aluminium with magnesium as the next major constituent with silicon
C22F 1/05 - Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys of the Al-Si-Mg type, i.e. containing silicon and magnesium in approximately equal proportions
15.
RING FURNACE INCLUDING BAKING PITS WITH A LARGE HORIZONTAL ASPECT RATIO AND METHOD OF BAKING CARBONACEOUS ARTICLES THEREIN
The invention relates to a ring furnace (1) having a longitudinal axis and comprising elongated bays (10), a plurality of hollow partitions (3, 3') arranged within the casing of each bay so as to be parallel to the longitudinal axis, a first end transverse wall (41) located at a first end of each bay (10), a second end transverse wall (42) located at a second end of each bay (10) and possibly one or more intermediate transverse walls (43) located between the first and second ends. The hollow partitions and transverse walls define baking pits (2) within the bays (10) for stacking carbonaceous articles therein. The baking pits have a length Lp and a width Wp, said length Lp being at least 15 times greater than said width Wp.
The invention relates to a ring furnace (1) having a longitudinal axis and comprising elongated bays (10), a plurality of hollow partitions (3, 3') arranged within the casing of each bay so as to be parallel to the longitudinal axis, a first end transverse wall (41) located at a first end of each bay (10), a second end transverse wall (42) located at a second end of each bay (10) and possibly one or more intermediate transverse walls (43) located between the first and second ends. The hollow partitions and transverse walls define baking pits (2) within the bays (10) for stacking carbonaceous articles therein. The baking pits have a length Lp and a width Wp, said length Lp being at least 15 times greater than said width Wp.
The invention describes a process and apparatus producing a dense coke fraction from a first particulate coke fraction having a first average density and a first average particle size distribution, stratifying the coke fraction in a density separator into at least two fractions, the at least two fractions comprising a light coke fraction and the dense coke fraction. The dense fraction having an average density greater than the first average density and a particle size distribution substantially equivalent to the first average particle size distribution. The apparatus includes an inclined oscillating table comprising a gas-pervious deck, and a gas mover.
C10B 57/00 - Other carbonising or coking processesFeatures of destructive distillation processes in general
B07B 4/08 - Separating solids from solids by subjecting their mixture to gas currents while the mixtures are supported by sieves, screens, or like mechanical elements
The invention relates to an electrolytic cell (1) intended for production of aluminium including at least one collector bar (6) made of first metal and at least one complementary bar (20, 20') made of a second metal having an electrical conductivity greater than the first metal and arranged adjacent to one of the side faces of the collector bar (6) so that the external end (202, 202') of the complementary bar (20, 20') is at a specified distance A, A' from a specified end face (51, 51') of the block (5). The second end (202, 202') preferably terminates so as to limit heat losses from said cell (1). The invention makes it possible to obtain significantly lower voltage drops than known cells while avoiding excessive heat losses through the collector bars.
An apparatus and a method for tapping molten metal from below a molten electrolyte layer less dense than the metal is described. The apparatus comprises a pipe comprising a protruding enlarged wall portion at an operative end which is immersed in the molten electrolyte and metal during tapping operation. The enlarged wall portion helps to minimize entrainment of electrolyte residue from the electrolyte/metal interface during tapping. The orientation of the enlarged wall portion may be in the general direction of the crucible.
The invention relates to a metal boride precursor mixture comprising a metal oxide and a boric oxide combined in such a manner so as to produce intimately linked clusters wherein the boric oxide is found within the metal oxide. Furthermore, the invention discloses a carbon composite material made with the metal boride precursor mixture and a carbonaceous component. Finally, the invention also teaches the process for preparing the metal boride precursor mixture comprising steps of providing a metal oxide and a boron oxide, mechanically mixing the metal oxide and the boron oxide at a temperature that liquefies the boron oxide and may impregnate the metal oxide to produce an intimately linked cluster of metal oxide and boric oxide.
The invention relates to a process for fabricating aluminium nitride in which a multilayer structure comprising aluminium-based laminated products are prepared by stacking or winding them and said multilayer structure is heated in a nitrogen-containing atmosphere, most of the nitriding taking place during a phase in which the temperature of the nitrogen-containing atmosphere is maintained between 400°C and 660°C. The invention makes it possible to obtain aluminium nitride by an economic process that requires neither the use of aluminium powder as raw material nor the use of very high temperatures. The aluminium nitride obtained comprises particles the microscopic structure of which is laminated.
A method is described for priming an in-line molten metal filtration unit having a porous ceramic or refractory filter mounted substantially horizontally in a filter box. This filter box has an inlet for molten metal and an outlet for molten metal, the outlet being a closeable outlet in an exit well connecting to the downstream side of the filter. The method of the invention comprises the steps of adding a molten metal to the filter box sufficient to entirely cover the upstream side of the filter with a depth of molten metal and temporarily sealing the outlet in the exit well. A steadily increasing vacuum is then applied to the closed exit well at a rate between 0.1 and 10 kPa per second by withdrawing a stream of air from the exit well by means of a fan or air venturi until molten metal begins to flow through the filter. At that point the vacuum is quickly released and the molten metal outlet is opened. Once the filter has been primed in this manner, flow of metal through the filter continues while requiring only a relatively low head of molten metal on the inlet side of the filter.
A shaped metal casting made in an aggregate mold comprises fine solidification microstructure that is finer than the solidification microstructure of an analogous metal casting made from conventional molding processes. The solidification microstructure may be up to five times finer than the solidification microstructure of a conventionally prepared casting. In preferred embodiments, as a result of directional solidification, the fine solidification microstructure is substantially continuous from a distal end of the casting to a proximal end of the casting, and exhibits greatly enhanced soundness. Because of the control of the uniformity of freezing of the casting, its properties are substantially uniform.
The present invention describes an apparatus and a process for in-line substantially continuous degassing of aluminium and/or aluminium alloys, in absence of chlorine and through the injection of at least one metal halide salt that includes a halogen and water and an inert gas, in a transfer trough before casting.
C22B 9/10 - General processes of refining or remelting of metalsApparatus for electroslag or arc remelting of metals with refining or fluxing agentsUse of materials therefor
C22B 9/05 - Refining by treating with gases, e.g. gas flushing
26.
APPARATUS FOR PRODUCTION, WITHDRAWAL AND TRANSFER OF HIGHLY VISCOUS SLURRY
Method and apparatus for separating components of slurries by gravity settling thereby forming a thickened slurry and a clarified liquid The apparatus comprises a vessel for decanting a volume of slurry, a slurry mlet means, an outlet for the clarified liquid, and a slurry withdrawal apparatus for removal of the thickened slurry from the vessel at or near a bottom wall thereof The slurry withdrawal apparatus physically engages a portion of the slurry withm the vessel interior and transports it through a vessel outlet The apparatus may include an elongated, rotatable, open spiral-shaped element extending a distance into the vessel from outside near the bottom wall of the vessel, the open spiral-shaped element being in direct and open communication with the interior of the vessel over at least a significant portion of the distance, and a rotational drive mechanism for rotating the open spiral-shaped element, at least intermittently
Method and apparatus for separating components of slurries by gravity settling thereby forming a thickened slurry and a clarified liquid The apparatus comprises a vessel for decanting a volume of slurry, a slurry mlet means, an outlet for the clarified liquid, and a slurry withdrawal apparatus for removal of the thickened slurry from the vessel at or near a bottom wall thereof The slurry withdrawal apparatus physically engages a portion of the slurry withm the vessel interior and transports it through a vessel outlet The apparatus may include an elongated, rotatable, open spiral-shaped element extending a distance into the vessel from outside near the bottom wall of the vessel, the open spiral-shaped element being in direct and open communication with the interior of the vessel over at least a significant portion of the distance, and a rotational drive mechanism for rotating the open spiral-shaped element, at least intermittently
Method and apparatus for separating components of slurries by gravity settling thereby forming a thickened slurry and a clarified liquid. The apparatus comprises a vessel for decanting a volume of slurry, the vessel having a top and an interior formed by a side wall and a bottom wall for holding the slurry, a slurry inlet means, an outlet for the clarified liquid near the top of the vessel, and a slurry withdrawal apparatus for removal of the thickened slurry from the vessel at or near the bottom wall thereof. The slurry withdrawal apparatus physically engages a portion of the slurry within the vessel interior and transports it through a vessel outlet. The apparatus may include an elongated, rotatable, open spiral-shaped element extending a distance into the vessel from outside near the bottom wall of the vessel, the open spiral-shaped element being in direct and open communication with the interior of the vessel over at least a significant portion of the distance, and a rotational drive mechanism for rotating the open spiral-shaped element, at least intermittently.
A device is provided for measuring metal inclusions comprising a receptacle for holding a sample of molten metal, with this receptacle having insulated side walls and a bottom wall provided with an exit opening. A ceramic filter element for collecting inclusions from the molten metal is positioned within the exit opening and is bonded to the top face of a solid refractory or metal annular support ring with a portion of the support ring top face extending laterally beyond the filter element and engaging the bottom face of the bottom wall of the receptacle around the opening. The filter element and support ring assembly is held in place by a detachable retaining means which is adapted to securely hold the support ring in leak-tight engagement against the receptacle bottom wall with the filter element positioned in the exit opening.
The present invention provides extruded tubes for heat exchangers having improved corrosion resistance when used alone and when part of a brazed heat exchanger assembly with compatible finstock. The tubes are formed from a first aluminum alloy containing 0.4 to 1.1% by weight manganese, up to 0.01% by weight copper, up to 0.05% by weight zinc, up to 0.2% by weight iron, up to 0.2% by weight silicon, up to 0.01% by weight nickel, up to 0.05% by weight titanium and the balance aluminum and incidental impurities. The fins are formed from a second aluminum alloy containing 0.9 to 1.5% by weight manganese or an alloy of the AA3003 type, this second aluminum alloy further containing at least 0.5% by weight zinc.
A cast composite material is prepared by furnishing an aluminum-based matrix alloy and forming a mixture of free-flowing boron carbide particles and the aluminum-based matrix alloy in molten form which is stirred to wet the matrix alloy to the boron carbide particles and to distribute the particles throughout the volume of the melt. The molten mixture is then cast. The fluidity of the molten mixture is maintained by (a) maintaining the magnesium content of the matrix metal below about 0.2% by weight, or (b) starting with a matrix metal containing less than 0.2% by weight magnesium and adding further magnesium to the mixture a short time before casting, or (c) having at least 0.2% by weight titanium present in the mixture.
A method is described for reclaiming an Al-B4C composite scrap material. The method involves heating a liquid pool of molten aluminum while also pre-heating the scrap material. The scrap material is then added to the molten aluminum and a predetermined melt temperature is maintained in the liquid pool until all of the scrap material melts into the molten aluminum to form a resultant composite melt. Finally, the resultant composite melt is stirred to promote uniformity. A method is also described for preparing a B4C-containing aluminum cast composite products that involves preparing a mixture of free-flowing B4C particles and molten aluminum and stirring the mixture to wet the aluminum to the B4C particles. The mixture is then cast into a cast composite material and processed to form the cast composite product and Al-B4C composite scrap material. The scrap material is then reclaimed by the method described above.
A method is described for priming an in-line molten metal filtration unit having a porous ceramic or refractory filter mounted substantially horizontally in a filter box. This filter box has an inlet for molten metal and an outlet for molten metal, the outlet being a closeable outlet in an exit well connecting to the downstream side of the filter. The method of the invention comprises the steps of adding a molten metal to the filter box sufficient to entirely cover the upstream side of the filter with a depth of molten metal and temporarily sealing the outlet in the exit well. A steadily increasing vacuum is then applied to the closed exit well at a rate between 0.1 and 10 kPa per second by withdrawing a stream of air from the exit well by means of a fan or air venturi until molten metal begins to flow through the filter. At that point the vacuum is quickly released and the molten metal outlet is opened. Once the filter has been primed in this manner, flow of metal through the filter continues while requiring only a relatively low head of molten metal on the inlet side of the filter.
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