Abstract: A method is described for preheating annealing goods in a hood-type annealing installation, comprising two annealing bases (1, 2) which accommodate the annealing goods (3, 4) under a protective cover (7, 8), with the annealing goods (3) to be subjected to a heat treatment under a protective cover (8) being preheated with the help of a gaseous heat carrier which is guided in a cycle between two protective covers (7, 8) and absorbs heat from annealing goods (4) which are heat-treated in a protective cover (7) and emits it to the annealing goods (3) to be preheated in the other protective cover (8). In order to avoid contaminations of the heat-treated annealing goods (4) it is proposed that the heat carrier flow guided in a cycle flows around the two protective covers (7, 8) on the outside, whereas a protective gas is circulated within the protective covers (7, 8).

Abstract: A device is described for heat-treating sheet metal strips (6), comprising at least one radiant tube unit (1) which has three tubes disposed in a common plane parallel to the sheet metal strip (6), namely a middle tube (2) that can be connected to a burner and two outer tubes (3) that are connected at both ends to the middle tube (2) by means of tube bends (4), and a bearing (8) on the side of the radiant tube unit (1) opposite the burner for a bearing journal (9) connected to the two tube bends (4) between the middle tube (2) on the one hand and the two outer tubes (3) on the other hand, the bearing journal engaging in a journal receptacle (10) of the bearing (8) in an axially displaceable manner. In order to provide advantageous constructional conditions it is proposed that an insert (16) forming a sliding layer (15) is provided in the support area of the bearing journal (9) between the journal receptacle (10) of the bearing (8) and the bearing journal (9).

Abstract: A method is described for heating lightweight metal ingots (1), with the lightweight metal ingots (1) being heated in a furnace (2) by hot burner exhaust gases. In order to provide advantageous heating conditions it is proposed that the lightweight metal ingots (1), prior to their heating in the furnace (2), are preheated via at least one preheating apparatus (9) which rests in a planar manner thereon and is supplied by a fluid heat carrier which is heated in heat exchange by the hot exhaust gases from the furnace (2) and is guided in a circuit (7).

Abstract: A high-temperature furnace for the annealing of sheet-metal joints (4) is described, having an annealing base (2), having a support device (3), which forms a placement surface (17) for coaxially receiving a sheet-metal joint (4) with spacing above the annealing base (2), having a protective hood (6), which coaxially encloses the annealing base (2) with the support device (3), and is connected to a protective gas supply line (10) and a protective gas exhaust, made of a cylindrical jacket (7) and a cupola (16) which terminates the jacket (7) on top, having a peripheral seal (9) between the annealing base (2) and the protective hood (6), and having a heating hood (13) which encloses the protective hood (6) with spacing.

Abstract: A method is described for preheating annealing goods in a hood-type annealing installation, comprising two annealing bases (1, 2) which accommodate the annealing goods (3, 4) under a protective cover (7, 8), with the annealing goods (3) to be subjected to a heat treatment under a protective cover (8) being preheated with the help of a gaseous heat carrier which is guided in a cycle between two protective covers (7, 8) and absorbs heat from annealing goods (4) which are heat-treated in a protective cover (7) and emits it to the annealing goods (3) to be preheated in the other protective cover (8). In order to avoid contaminations of the heat-treated annealing goods (4) it is proposed that the heat carrier flow guided in a cycle flows around the two protective covers (7, 8) on the outside, whereas a protective gas is circulated within the protective covers (7, 8).

Abstract: The invention relates to a heat exchanger (1) for an annealing furnace for exchanging heat between two fluids, comprising a tubular profile which comprises heat exchanger fins on its outside jacket and which is associated on at least one face side (3) with a connecting flange (4) with at least one flow opening (8) for one of the two fluids, especially a hot gas. In order to provide advantageous constructional conditions it is proposed that the profile is a profile tube made of a folded sheet whose heat exchanger fins (7) aligned in the longitudinal direction of the profile are formed by the corrugated profile, especially the corrugated flanks, of the folded sheet.

Abstract: An apparatus is described for bracing of sheet-metal joints (1) in a high-temperature annealing furnace having at least one carrier (2), which frontally receives a sheet-metal joint (1) and has a central axial passage opening (6), on which a support pipe (5), which axially penetrates the sheet-metal joint (1), having a carrier (2) for receiving a further sheet-metal joint (1) can optionally be placed in a load-bearing manner. In order to provide advantageous heating conditions, it is proposed that the carrier (2) has a ring body (7) forming the passage opening (6), having radially protruding carrier arms (8) distributed around the circumference.

Abstract: A method is described for batchwise heat treatment of goods to be annealed which are heated in a heating chamber after scavenging air with a scavenging gas under protective gas to a predetermined treatment temperature, with the protective gas being conveyed through the heating chamber depending on the occurrence of impurities in different quantities. In order to enable the economic use of protective gas, it is proposed that the protective gas which is withdrawn from the heating chamber after the main occurrence of impurities and which is loaded with a residual quantity of impurities is conveyed, optionally after intermediate storage, into the heating chamber during the main occurrence of impurities of a subsequent batch before non-loaded protective gas is introduced into the heating chamber.

Abstract: An apparatus is described for cooling a strip (1) of sheet metal with nozzles (6) for a cooling liquid to be sprayed onto the bottom side of the strip, which nozzles are arranged beneath the strip (1) in transversal rows relative to the feeding direction (3) of the strip. In order to provide advantageous cooling conditions it is proposed that the nozzles (6) configured as fan jet nozzles form a common middle spraying surface (7) for each transversal row and that covers (10) are provided in the spraying region of the nozzles (6) which are laterally adjacent to the strip (1) of sheet metal.

Abstract: The invention describes a hood-type annealing furnace, especially for steel strip or wire bunches, with an annealing base (1) for receiving the material (7) to be annealed, a protective hood (8) which is placed on the furnace in a gas-tight manner, a radial blower (2) which is held in the annealing base (1) and comprises a blade wheel (3) and a guide apparatus (5) enclosing the blade wheel (3) for circulating a protective gas in the protective hood (8), a heat exchanger (11) for cooling the protective gas, which heat exchanger (11) is connected on the input side via a flow conduit (13) with the pressure side of the radial blower (2) and opens on the output side in an annular gap (12) between the guide apparatus (5) and the protective hood (8), and a deflection device which is axially displaceable into the pressure-side flow path of the radial blower (2) for the optional connection to the radial blower (2) of the flow conduit (13) which leads to the heat exchanger (11).

Abstract: An apparatus is disclosed, which serves to contact with a flowing gas two mutually opposite, substantially flat and substantially circular annular surfaces of an annular cylindrical workpiece having an inside diameter not in excess of a predetermined maximum inside diameter. The apparatus comprises an oven housing, which contains two mutually opposite plenum chambers, which are defined by respective side walls which are spaced apart in an axial direction and define between them an oven chamber adapted to accommodate said workpiece in a position in which each of said side walls faces one of said surfaces of said workpiece, each of said side walls being formed with orifice slot means, and a fan for supplying a gas to said plenum chambers.