Abstract: A solar collector receiver tube containing an improved getter system is described. The solar collector receiver tube has a base, pills of getter material that are uniform in height, and a containment metallic mesh having a non-uniform height and presenting at least one depression.

Abstract: A solar collector receiver tube containing an improved getter system is described. The solar collector receiver tube has a base, pills of getter material that are uniform in height, and a containment metallic mesh having a non-uniform height and presenting at least one depression.

Abstract: A burner for a vapour deposition process has a central nozzle for ejecting a glass precursor material, at least a crown of nozzles surrounding said central nozzle for ejecting a flame reactant, and a circular nozzle between said central nozzle and said crown of nozzles for ejecting an innershield gas, wherein the central nozzle has a concave shape in a cross section in the axial plane and, preferably, a symmetry about an axial plane.

Abstract: A method and device for manufacturing a preform for optical fibers through chemical deposition on a substrate for deposition arranged vertically is described, comprising a chemical deposition chamber including at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated element constituting a substrate for chemical deposition for the formation of a preform for optical fibers. The chamber includes, moreover, at least one burner which is mobile along a direction Z substantially parallel to said axis Z-Z and adapted to deposit, on said at least one elongated element, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances, said at least one suction element being arranged on the opposite side to said at least one burner with respect to said axis Z-Z and being mobile along said direction Z.

Abstract: An induction furnace capable of drawing large diameter preforms of up to 130 mm is described. The induction furnace has top and bottom chimneys surrounding the entire preform during operation of the furnace with an inert conditioning gas which is introduced into the top chimney and flows downward through the furnace body and bottom chimney without significant turbulence. A distributor ring inside the top chimney redirects flow from a circumferential direction to a downward direction. The top chimney also includes a resilient seal to releasably hold the top of the preform. The bottom chimney has a smoothly decreasing cross-sectional area preventing turbulence at the furnace exit. The furnace insulation is preferably a rigid self-supporting graphite cylinder. A method of drawing large diameter preforms either to an optical fiber or to a preform of smaller diameter using such a furnace is also described.

Abstract: An intermediate preform is formed in a process of manufacturing an optical fibre by forming a sol containing a glass precursor; pouring the sol in a mold containing a set of elongate elements; aging the sol to obtain a gel body; removing the set of elongate elements from the gel body to create a corresponding set of holes in the gel body; and removing the gel body from the mold. The method further provides imparting a motion of the set of elongate elements during aging of the sol to avoid adhesion of the gel to the elongate elements, the motion being preferably a rotation about the respective axes or an alternate translation along the respective axes. An apparatus with means for carrying out the method is also described.

Abstract: A method is disclosed for feeding a flow of gas to a burner for manufacturing an optical fibre preform, said burner comprising: a plurality of coaxial tubes, each two adjacent coaxial tubes defining an annular channel between themselves; an annular gas distribution chamber at one extremity of said annular channels and in fluid communication therewith, said annular distribution chamber being delimited in the radial direction by an inner and an outer surface; said method comprising introducing the flow of gas into the distribution chamber so that the direction of its radially outermost portion is tangential to the radially outer surface of the distribution chamber. The method allows obtaining a better gas velocity distribution in said annular channels. A burner for performing said method is also disclosed.

Abstract: A method for feeding a flow of gas to a burner for manufacturing an optical fiber preform. The burner has a plurality of coaxial tubes, each two adjacent coaxial tubes defining an annular channel between themselves; an annular gas distribution chamber at one extremity of the annular channels and in fluid communication therewith, the annular distribution chamber being delimited in the radial direction by an inner and an outer surface. The flow of gas is introduced into the distribution chamber so that the direction of its radially outermost portion is tangential to the radially outer surface of the distribution chamber. The method allows obtaining a better gas velocity distribution in the annular channels.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically is described, comprising a chemical deposition chamber including at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated element constituting a substrate for chemical deposition for the formation of a preform for optical fibres. The chamber includes, moreover, at least one burner which is mobile along a direction Z substantially parallel to said axis Z-Z and adapted to deposit, on said at least one elongated element, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances, said at least one suction element being arranged on the opposite side to said at least one burner with respect to said axis Z-Z and being mobile along said direction Z.

Abstract: A device including at least one gripping member, rotatably mounted about an axis Z-Z, adapted to hold at least one end of at least one elongated element for chemical vapour deposition for forming a preform. The device includes at least one burner being mobile along a direction substantially parallel to the axis Z-Z and adapted to deposit, on the elongated element, a chemical substance for forming a preform, and at least one suction element arranged on the opposite side of the burner on a portion of a wall of the device on the opposite side of the gripping member from the burner. At least one air suction member, mobile along direction Z, is provided with motion synchronous with respect to the burner. The wall with the air suction member has a pair of respective upper and lower tapes rigidly associated with the burner.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically. A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated substrate for chemical deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction Z substantially parallel to the axis Z-Z and adapted to deposit on the elongated substrate, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances. The suction element is arranged on the opposite side of the burner with respect to the axis Z-Z and is mobile along the direction Z and is positioned at a lower height than the burner.

Abstract: A device for manufacturing a preform of glass material for optical fibres. A chemical deposition chamber, at least one burner mobile along a direction Z and adapted to deposit a chemical substance on at least an elongated element positioned along an axis Z-Z, at least one suction element mobile along the direction Z for collecting exhaust chemical substances, a collector tube associated with the at least one suction element and adapted to discharge the exhaust chemical substances outside the chemical deposition chamber through an exhaust opening formed on a wall of the chamber, and a coupling device between the collector tube and the wall at the exhaust opening, allowing sliding of the collector along the direction Z and along a direction X towards/away from the axis z-z.

Abstract: The present invention discloses a system and method for implementing prepaid data services in a mobile communication network. In this system, a Data service Access Control Point (DACP), which is used for fulfilling price confirmation function and fee application function for data services, is added between a Service Control Point (SCP) storing prepaid account information of subscribers and a Prepaid Server/Content of Process Gateway (PPS/CP GW) used for data service charging. In the method of the present invention, by means of the interaction among a Packet Data Service Note (PDSN), a Home Authentication Authorization and Accounting (HAAA) server, the PPS/CP GW, the DACP and the SCP, the SCP deducts the fees from the prepaid account, and the PDSN controls the subscriber to utilize data service according to the fees deducted by the SCP.

Abstract: An intermediate preform is formed in a process of manufacturing an optical fibre by forming a sol containing a glass precursor; pouring the sol in a mold containing a set of elongate elements; aging the sol to obtain a gel body; removing the set of elongate elements from the gel body to create a corresponding set of holes in the gel body; and removing the gel body from the mold. The method further provides imparting a motion of the set of elongate elements during aging of the sol to avoid adhesion of the gel to the elongate elements, the motion being preferably a rotation about the respective axes or an alternate translation along the respective axes. An apparatus with means for carrying out the method is also described.

Abstract: A method of producing a preform for a holey optical fiber having at least one hole longitudinally extending therethrough. A porous preform, such as a glass soot preform, is formed by means of flame hydrolysis, or a gel preform; at least one hole is then formed by drilling the porous preform, the hole extending through the porous preform along the longitudinal direction thereof. A holey fiber can be produced by drawing the holey porous preform, after having submitted it to a consolidation process.

Abstract: A burner for a vapour deposition process has a central nozzle for ejecting a glass precursor material, at least a crown of nozzles surrounding said central nozzle for ejecting a flame reactant, and a circular nozzle between said central nozzle and said crown of nozzles for ejecting an innershield gas, wherein the central nozzle has a concave shape in a cross section in the axial plane and, preferably, a symmetry about an axial plane.

Abstract: A method for feeding a flow of gas to a burner for manufacturing an optical fibre preform. The burner has a plurality of coaxial tubes, each two adjacent coaxial tubes defining an annular channel between themselves; an annular gas distribution chamber at one extremity of the annular channels and in fluid communication therewith, the annular distribution chamber being delimited in the radial direction by an inner and an outer surface. The flow of gas is introduced into the distribution chamber so that the direction of its radially outermost portion is tangential to the radially outer surface of the distribution chamber. The method allows obtaining a better gas velocity distribution in the annular channels.

Abstract: A device for manufacturing a preform of glass material for optical fibres. A chemical deposition chamber, at least one burner mobile along a direction Z and adapted to deposit a chemical substance on at least an elongated element positioned along an axis Z-Z, at least one suction element mobile along the direction Z for collecting exhaust chemical substances, a collector tube associated with the at least one suction element and adapted to discharge the exhaust chemical substances outside the chemical deposition chamber through an exhaust opening formed on a wall of the chamber, and a coupling device between the collector tube and the wall at the exhaust opening, allowing sliding of the collector along the direction Z and along a direction X towards/away from the axis z-z.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically. A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated substrate for chemical deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction Z substantially parallel to the axis Z-Z and adapted to deposit on the elongated substrate, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances. The suction element is arranged on the opposite side of the burner with respect to the axis Z-Z and is mobile along the direction Z and is positioned at a lower height than the burner.

Abstract: A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z adapted to hold at least one end of at least one elongated element for chemical vapour deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction substantially parallel to the axis Z-Z and adapted to deposit, on the elongated element, a chemical substance for the formation of a preform, and at least one suction element arranged on the opposite side of the burner on a portion of a wall of the chamber on the opposite side of the gripping member from the burner. At least one air suction member, mobile along direction Z, is provided with a motion which is synchronous with respect to that of the burner. The chamber wall on which the air suction member is provided has a pair of respective upper and lower tapes rigidly associated with the burner.