Abstract: The invention relates to a simplified production process with which it is possible to obtain carbon blocks, in particular anodes intended for aluminium production using the Hall-Héroult electrolysis process, which have high thermal shock resistance. This process comprises a grain size distribution adjustment operation of a carbon aggregate which includes: a) separating an initial ungraded carbon aggregate AC into a first fraction F1 made up of grains whose sizes are smaller than X, and into a second fraction F2 made up of grains whose sizes are X or greater, X lying between 0.2 and 2 mm; b) crushing B1 the first fraction F1 and part P1 of the second fraction F2 such as to obtain a powder F comprising a controlled proportion of ultra-fine grains; c) mixing the remaining part P2 of fraction F2 and said powder F in proportions with which it is possible to obtain crude carbon blocks whose so-called “Gr/S” ratio between the proportion PGr of grains larger than 0.

Abstract: The invention relates to a ring furnace pit (2) cooling method, comprising the production of a flux F of cooling fluid inside the pit (2) and the flow of at least a part Fr of said flux F in a roughly vertical manner along determined surfaces of the walls (2A, 2B) of the pit (2). The invention also relates to a device capable of implementing the method.

Abstract: The present invention relates in general to optical waveguide devices, which preferably are planar, e.g., optical arrayed waveguide gratings (AWGs), multiplexers/demultiplexers, optical add/drop multiplexers and the like. More particularly, the present invention provides integrated optical waveguide devices having central wavelengths (or channel wavelengths) which are temperature insensitive in that they do not or do almost not shift upon temperature variations in the environment. Such devices are also called athermalized or athermal devices. Preferably, most or all parts of such devices including waveguides, cladding material and the substrate itself consist of organic polymeric materials. The devices of the invention substantially remedy the problems encountered with the limitations and disadvantages of common devices as known in the prior art.

Abstract: The present invention is directed to wave guide systems or structures or parts thereof, characterized in that they consist of or comprise a resin composed of at least one polycyanate copolymer, obtainable by copolymerization of at least one specific difunctional cyanate with at least one monocyanate of the formula N≡—C—O—R, wherein R is a straight or branched non-aromatic hydrocarbon radical or a non-aromatic hydrocarbon radical comprising a cyclic structure, the radical having the formula C(R′)2—CFR″2 wherein each R′ is, independently from the other, hydrogen or fluorine or an optionally substituted, preferably fluorinated alkyl or alkenyl group, and each of R″ may independently be defined as R′ or may have an arylic structure.

Abstract: The present invention relates in general to optical waveguide devices, which preferably are planar, e.g., optical arrayed waveguide gratings (AWGs), multiplexers/demultiplexers, optical add/drop multiplexers and the like. More particularly, the present invention provides integrated optical waveguide devices having central wavelengths (or channel wavelengths) which are temperature insensitive in that they do not or do almost not shift upon temperature variations in the environment. Such devices are also called athermalized or athermal devices. Preferably, most or all parts of such devices including waveguides, cladding material and the substrate itself consist of organic polymeric materials. The devices of the invention substantially remedy the problems encountered with the limitations and disadvantages of common devices as known in the prior art.

Abstract: The present invention relates in general to optical waveguide devices, which preferably are planar, e.g., optical arrayed waveguide gratings (AWGs), multiplexers/demultiplexers, optical add/drop multiplexers and the like. More particularly, the present invention provides integrated optical waveguide devices having central wavelengths (or channel wavelengths) which are temperature insensitive in that they do not or do almost not shift upon temperature variations in the environment. Such devices are also called athermalized or athermal devices. Preferably, most or all parts of such devices including waveguides, cladding material and the substrate itself consist of organic polymeric materials. The devices of the invention substantially remedy the problems encountered with the limitations and disadvantages of common devices as known in the prior art.

Abstract: A process for regulating a furnace which includes a sequence of sections, cooling sections, baking sections, and preheating sections, in which the preheating sections at the tail are fitted with exhaust pipes for combustion gases, and in the transverse direction with a series of flue walls and pits in which blocks containing carbon to be baked are stacked, in which gas streams circulate through the flue walls. The mass flow in each of the streams of combustion exhaust gases is regulated by measuring this flow and the temperature in order to obtain a predetermined set value of energy flux.

Abstract: The furnace for baking carbonaceous blocks comprises, along the longitudinal X direction of the furnace, a series of sections, each section comprising, in the transverse Y direction, hollow walls (3) through which a heating gas flow comprising combustion gas or a cooling air flow circulates, alternating with pits containing carbonaceous blocks to be baked, each of the said hollow walls (3) in a section being in communication with a wall in an upstream section and/or a wall in a downstream section, so as to form a conduit through which the said gas flow circulates, each of the said walls of a section comprising two vertical lateral partitions (38) in the X-Z plane, and elements in the transverse Y direction for deflecting the said gas flow passing through the said wall and maintaining a constant spacing between the said lateral partitions (38), and characterized in that each wall (3) comprises a means of maintaining, over at least one third of the length L of said wall, a gas flow of rate D uniformly distribut

Abstract: A process as disclosed for constructing a furnace for open chambers for baking carbonaceous blocks, comprising arranging a plurality of chambers in a series or in two parallel series, each chamber being defined by lateral partitions and transverse partitions, disposing the plurality of chambers within an independent concrete casing formed by a floor and lateral wall portions having disposed thereof a plurality of vertical buttresses and compressively prestressing the vertical buttresses in the vertical direction. A horizontal force may also be applied to the upper part of the transverse partitions.

Abstract: The invention concerns a process and an apparatus for optimizing combustion in a furnace which has open chambers, referred to as a ring furnace, for the baking of carbonaceous blocks, the furnace comprising a plurality of preheating, baking and cooling chambers which are aligned in series, each chamber being formed by the alternating juxtaposition of hollow heating partitions in which the combustion gases circulate and compartments in which the carbonaceous blocks to be baked are stacked, the combustion gases being extracted by a suction pipe connected by delivery tubes to each of the heating partitions of the first natural preheating chamber.

Abstract: The invention concerns an improvement in a suction or blowing pipe for a furnace having partition chambers intended for the firing of carbonaceous blocks. The pipe comprises a main body (3) provided with a plurality of nozzles (10) to which tubular nipples (2) are connected in a number equal to the number or partitions (5) forming the chambers of the furnace. Each of the nipples is connected to a transverse furnace wall (9) or a partition (5) by a taphole (8) disposed in the upper part of the wall or partition.