Sandvik Intellectual Property Ab

Sandvik Ab

Kanthal Ab

Thomas Lewin

Pauli Mäenpää

Bo Jönsson

Thomas Helander

Dilip Chandrasekaran

Thomas Odelstam

Jan Innerman

Jörgen Sjöberg

Ole Stadum

Kari Korhonen

Anke Krönert

Sune Linden

Hans L&ouml;vgren

Jonas Magnusson

Sune Lind N

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.

Heater element as well as an insert for electrical furnaces

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.

Electric heating device

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

Use and method of producing a dispersion strengthened steel as material in a roller for a roller hearth furnace

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.

Insert and a heater element for electrical furnaces

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.

Electrical heating element for vertical installation

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.

Method to supply electric current to a tube furnace

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 NOis formed.

Method of combustion with the aid of burners in industrial furnaces, and a burner to this end

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.

Method and device for igniting and monitoring a burner

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.

Heat conductor support disc

An electric heating element with radiant tube comprising a radiation pipe () and an electric heating element () contained in said pipe, wherein the heating element has legs that run to and fro in the pipe, and wherein the heating element is connected at one end of the pipe close to a furnace wall with electric power outlets through which electric current is fed to the element, wherein the element is supported in the pipe by ceramic discs () that are provided with through-penetrating holes through which the legs of the elements extend, and wherein two elements () are disposed sequentially in said radiation pipe along its long axis.

Electric heating element that includes a radiant tube

A method of cooling strip or wire products in which, subsequent to being annealed, the product is cooled to a temperature of about 20-50&#xb0; C. below its oxidation temperature. The product is wound around a drum immediately downstream of an annealing path so that the product lies in mutually juxtaposed turns on the drum. It is thereafter unwound from the drum after a number of turns. The number of turns is such that the product is cooled to a desired temperature. The drum has a diameter that exceeds the diameter at which the product will be influenced mechanically by plastic deformation.

Method and apparatus for cooling strip and wire material

The present invention relates to a method relating to the operation of a burner and/or cooler (), wherein gases are caused to flow through an inner pipe (), out into an outer pipe () which surrounds the inner pipe (), and back through that part of the volume of the outer pipe () not accommodated by the volume of the inner pipe (). The invention is characterised by placing an inner bottom plates () in the outer pipe () in spaced relationship with the closed bottom () of said outer pipe (), whereby the gases flowing through the inner pipe () and out into the outer pipe () are caused to turn back and pass between the outer pipe () and the inner pipe (), thereby creating a gas pocket () between the bottom () of said outer pipe () and the bottom plate ().

Method gas burner and a combined gas burner and cooler with gas insulation

A method of supporting vertically hanging electrical resistance elements for heating furnaces or ovens in industrial operations. Each resistance element includes current-conducting legs that extend downward and upward a number of times, and the element includes along its length a number of ceramic discs that are provided with through-holes through which respective element legs extend. The upper part of the element merges with terminals that are connected to a source of electric current. The element is supported by at least one of the uppermost ceramic discs, wherein the uppermost ceramic disc supporting the element is placed in the insulation of the furnace roof above the underside of the roof. The legs of the element are short circuited at a location slightly or somewhat beneath the underside of the furnace roof with the aid of short circuiting plates.

Method and arrangement for supporting vertically depending electrical resistance elements

A gas burner in which a burner head is positioned within an inner pipe that is surrounded by an outer protective pipe. Fuel is delivered to the burner head through a fuel conduit positioned within the inner pipe, and combustion air is delivered through the inner pipe. The fuel conduit terminates short of the burner head and the wall of that conduit is provided with a plurality of holes. A further pipe surrounds at least the perforated part of the fuel conduit, and one end of the further pipe extends to the the burner head while the other end is sealed against the fuel conduit to form a mixing chamber between the outside of the fuel conduit and the inside of the further pipe. A second conduit is provided to conduct a given amount of air to the mixing chamber.

Growing community of inventors

Hallstahammar, Sweden

Thomas Lewin