Abstract: A heating element comprises a main body having a three-dimensional matrix with an open structure including openings and internal voids, cavities and/or pores extending throughout the main body. The three-dimensional matrix is provided as a lattice having a repeating unit cell extending in three directions. The present heating element is adapted for maximised surface area so as to provide an effective and efficient thermal energy transfer medium.

Abstract: A tube is disclosed comprising an inlet portion, an outlet portion, and a curved tube portion between the inlet and outlet portions. A vertical cross-section of the curved tube portion comprises two substantially straight inner delimiting surfaces meeting each other at an angle <100°. The present disclosure further relates to a method of manufacturing a tube, a computer program, and a computer-readable medium.

Abstract: Insert for electrical furnaces comprising an insulating shell and a coiled heater element, the heater element comprising element wire that consists of at least two sections that are interconnected via a bend of element wire in such a way that the bend and the sections mutually form a loop of element wire. A fastening member is fixedly anchored in the insulating shell and arranged in the area of the bend in such a way that the element wire in a section directly connected to the bend is prevented from expanding past the fastening member.

Abstract: Electric heating device with a radiant tube and an electrical heating element arranged in the radiant tube as well as a protective insert of electrically conductive material. The protective insert is arranged between the radiant tube and the electrical heating element. The device allows the use of higher element power.

Abstract: The present invention relates to a tunable microwave arrangement (100) comprising a waveguide arrangement and tuning elements comprising a number of varactors for tuning an electromagnetic signal input to the waveguide arrangement. It comprises a substrate (1), a layered structure (20) comprising at least two conducting layers (2,3) and at least one dielectric layer (4) which are arranged in an alternating manner. The layered structure is arranged on the substrate (1) such that a first of said conducting layers (2) is closest to the substrate (1). It also comprises at least one surface mounted waveguide (5), a second of the conducting layers (3), most distant from the substrate, being adapted to form a wall of the surface mounted waveguide (5), which wall incorporates said tuning elements which are arranged to enable control of surface currents generated in said wall, hence loading the waveguide (5) with a tunable, controllable impedance.

Abstract: A roller for a roller hearth furnace comprising a dispersion strengthened steel is disclosed. The roller does not require any coating or reconditioning.

Abstract: An insert intended for electrical furnaces and of the type that includes an insulating shell having an outside and an inside having a rotationally symmetrical, e.g., cylindrical shape, and a heater element that is arranged inside the insulating shell and extends several turns in a continuous loop having an overall shape corresponding to the rotationally symmetrical shape of the insulating shell. The continuous loop includes spaced-apart bends, which divide the same into individual sections of limited length to which occurring thermal expansion is isolated locally. In an exemplary embodiment, the bends are U-shaped to impart to the continuous loop a meander shape. Another exemplary embodiment relates to a heater element.

Abstract: An electrical heating element for vertical installation includes vertically suspended electrical resistance elements for the heating of furnaces in industrial operation, where each resistance element is formed of conductive legs, where along the length of the resistance elements are placed ceramic disks provided with holes, through which holes the relevant legs of the element pass. The ceramic disks are arranged between ceramic tubes and an upper metallic central rod is positioned within the ceramic tubes, which central rod supports the element and where the element is surrounded by a radiative tube. There are a number of upper ceramic tubes outside of the upper central rod with intermediate ceramic disks, and the central rod extends a certain distance down into the radiative tube.

Abstract: A method of and an arrangement for transmitting electric current to a furnace that is heated, either completely or partially, by electric current conducted in the furnace wall. The current is conducted through electrically conductive devices connected to the furnace wall. At least one of the devices in proximity to the furnace wall includes a section that has a smaller cross-sectional area than the remainder of the device. The current flow through the smaller cross-section develops heat in the region of the smaller section of a magnitude that corresponds substantially to the heat magnitude that would have been conducted from the furnace wall to the electrically conductive device in the absence of the smaller cross-sectional area.

Abstract: The present invention relates to a tunable microwave arrangement (100) comprising a waveguide arrangement and tuning elements comprising a number of varactors for tuning an electromagnetic signal input to the waveguide arrangement. It comprises a substrate (1), a layered structure (20) comprising at least two conducting layers (2,3) and at least one dielectric layer (4) which are arranged in an alternating manner. The layered structure is arranged on the substrate (1) such that a first of said conducting layers (2) is closest to the substrate (1). It also comprises at least one surface mounted waveguide (5), a second of the conducting layers (3), most distant from the substrate, being adapted to form a wall of the surface mounted waveguide (5), which wall incorporates said tuning elements which are arranged to enable control of surface currents generated in said wall, hence loading the waveguide (5) with a tunable, controllable impedance.

Abstract: Embodiments of the present invention relate to a self injection locked voltage controlled oscillator arrangement, a pair of coupled first and second voltage controlled oscillator devices are arranged on a chip, an amplifier device is arranged on the same of the refection type chip, and an off-chip delay line is arranged with one terminal connected to an output terminal of the coupled first and second voltage controlled oscillator devices, and on terminal adapted to reflect a signal from the output terminal, the amplifier device being arranged to amplify an injection signal from said output terminal and to supply the amplified injection signal to one of said first and second voltage controlled oscillation devices to provide a VCO arrangement that exhibits low phase noise and a small size.

Abstract: A capacitance arrangement comprising at least one parallel-plate capacitor comprising a first electrode means, a dielectric layer and a second electrode means partly overlapping each other. A misalignment limit is given. Said first electrode means comprises a first and a second electrode arranged symmetrically with respect to a longitudinal axis, said first and second electrodes have a respective first edge, which face each other, are linear and parallel such that a gap is defined there between. Said second electrode means comprises a third electrode with a first section and a second section disposed on opposite sides of said gap interconnected by means of an intermediate section, which is delimited by a function depending on a first parameter and a second parameter. One of said two parameters is adapted to be selected hence allowing calculation of the other parameter to determine the shape and size of the second electrode means.

Abstract: Method of combustion with a gas burner having a burner head at one end of an inner gas pipe surrounded by an outer protective pipe, wherein gases from the burner head flow inside the inner pipe and inside the outer pipe and thereafter flow into an exhaust channel. The inner pipe terminates short of the burner head; a sleeve downstream of the burner head, is inserted into and/or placed concentrically with the inner pipe so that the sleeve orifice is located within the inner pipe; a gap is provided between the opening of the inner pipe and the sleeve. The gap is sized such that the mixture of fuel and combustion air from the burner head and recycled exhaust gases passing through the gap will be mixed in quantities at which the temperature of combustion will be lower than the temperature in which NOx is formed.

Abstract: Electric heating device comprising a radiant tube and an electrical heating element arranged in the radiant tube as well as a protective insert of electrically conductive material. The protective insert is arranged between the radiant tube and the electrical heating element. The device allows the use of higher element power.

Abstract: A roller for a roller hearth furnace comprising a dispersion strengthened steel is disclosed. The roller does not require any coating or reconditioning.

Abstract: A method of igniting and monitoring a high speed burner with which a fuel/oxygen-mixture exits at high velocity from a burner head, wherein the length of the flame is governed by the exit velocity of the mixture. The invention is characterized by placing an electrically conductive pipe in and concentrical with the burner channel for the fuel mixture, by causing a first end of the pipe to terminate close to the fuel mixture outlet of the burner head, by electrically isolating the pipe and by causing the detection of light of the group ultraviolet light, visible light and/or infrared light to be detected at the other end of the pipe, and by causing a spark to be generated between the first end of the pipe and the surrounding burner head by application of a voltage, in igniting the burner. A burner is also disclosed.

Abstract: An electrical heating element for vertical installation, includes vertically suspended electrical resistance elements for heating furnaces in industrial operation, each element having conductive legs, where along the length of the element there are placed ceramic disks provided with holes, through which holes the relevant legs of the element pass, where the ceramic disks are arranged between ceramic tubes and where an upper metallic central rod is positioned within the ceramic tubes, which central rod supports the element and where the element is surrounded by a radiative tube. There are a number of upper ceramic tubes outside of the upper central rod, with intermediate ceramic disks. The central rod extends a certain distance down into the radiative tube. A number of lower ceramic tubes with intermediate ceramic disks are positioned outside of a lower central rod.

Abstract: This invention relates to an insert intended for electrical furnaces and of the type that comprises, on one hand, an insulating shell having an outside and an inside having a rotationally symmetrical, e.g., cylindrical shape, and on the other hand a heater element that is arranged inside the shell and extends a plurality of turns in a continuous loop having an overall shape corresponding to the rotationally symmetrical shape of the shell. According to the invention, the wire loop comprises a plurality of spaced-apart bends, which divide the same into a plurality of individual sections of limited length to which occurring thermal expansion is isolated locally. In a preferred embodiment, the bends are U-shaped to impart the wire loop meander shape. In an additional aspect, the invention also relates to a heater element as such.

Abstract: A ceramic heat conductor support disc for supporting an electrical heating element for electrically heated furnace installations. The support disc has a center aperture lying parallel to the longitudinal axis of the heating element, and one or more apertures located between the center aperture and the periphery of the disc. The disc is provided with one or more elongated openings running from the periphery to one of the apertures or to the center aperture, wherein each elongated opening penetrates the entire thickness of the disc.

Abstract: The invention discloses a varactor device (100) for improved temperature stability, comprising a first varactor (160) connected to a decoupling network (150). The device further comprises a voltage stabilizer (110), said stabilizer comprising a capacitor (140) and a temperature dependent capacitor (130), and in that the stabilizer comprises means for connection to a DC-feed (120). Suitably, the decoupling network (150) is connected in parallel to the first varactor (160), and the capacitor (140) of the voltage stabilizer (110) is connected in parallel to the decoupling network (150), the temperature dependent capacitor (130) of the voltage stabilizer (110) being connected in series to the diode of the voltage stabilizer (110).