Abstract: A casting mold (6) consists of two mold halves (4, 5), which are intended for setting up on both sides of the welding groove (3) between two rail ends (1, 2) to be connected, thereby forming a casting space (8) representing a cross-sectional profile of the rails. For sealing the casting space (8) between the rail bodies on both sides of the welding groove (3) and the wall portions (9, 10) of the casting mold (6) that are facing this welding groove, inserted in gaps (11, 12) are strips consisting of a compound at least containing expandable graphite, which as a result of heat being supplied during a preheating process expands and forms a reliable seal. In comparison with using filler sand at this point, there is the advantage that a much smaller quantity of compound has to be carried along when working on the laid track.

Abstract: A casting mold (6) consists of two mold halves (4, 5), which are intended for setting up on both sides of the welding groove (3) between two rail ends (1, 2) to be connected, thereby forming a casting space (8) representing a cross-sectional profile of the rails. For sealing the casting space (8) between the rail bodies on both sides of the welding groove (3) and the wall portions (9, 10) of the casting mold (6) that are facing this welding groove, inserted in gaps (11, 12) are strips consisting of a compound at least containing expandable graphite, which as a result of heat being supplied during a preheating process expands and forms a reliable seal. In comparison with using filler sand at this point, there is the advantage that a much smaller quantity of compound has to be carried along when working on the laid track.

Abstract: The invention relates to a heat generator for well stimulation, comprising a tubular fuel vessel (22) with two or more mutually separated, closed segments (23) arranged in longitudinal succession and each at least partly filled with fuel (30), and at least one igniter (40) for ignition of the fuel in at least one of the segments (23), wherein the ends of the segments are connected such that the fuel in a subsequent segment is ignitable owing to the evolution of heat in the course of burnoff of the fuel in a preceding segment. The invention further relates to a process for well stimulation using an inventive heat generator.

Abstract: The invention relates to a heat generator for well stimulation, comprising a tubular fuel vessel (22) with two or more mutually separated, closed segments (23) arranged in longitudinal succession and each at least partly filled with fuel (30), and at least one igniter (40) for ignition of the fuel in at least one of the segments (23), wherein the ends of the segments are connected such that the fuel in a subsequent segment is ignitable owing to the evolution of heat in the course of burnoff of the fuel in a preceding segment. The invention further relates to a process for well stimulation using an inventive heat generator.

Abstract: A preheating device intended for use in aluminothermic welding operations consists of a housing (12), which receives a nozzle (8) and is provided with a liquid gas feed (9), and a vaporizer (10), which is arranged downstream of the nozzle in the direction of flow, wherein the housing (12) has on its end facing a casting mould a combustion space, which ends in an outflow opening (11) for combustion gases and receives the nozzle, and a portion (22), which encloses the outflow opening (11) and can be inserted into an opening formed in the upper side of the casting mould, and wherein the vaporizer (10) is located between the outflow opening (11) and the nozzle (8), thereby being in heat exchange with the combustion gases.

Abstract: Device for the alumino-thermic welding of two ends of a rail A device for the alumino-thermic welding of two ends of a rail, namely a casting mould (4) which is open on the upperside and which comprises a central casting chamber which is defined by the rail ends, which are spaced apart from each other by a welding groove (3), and also by the walls of the casting mould (4) and to the side of the casting chamber said casting mould comprises at least one riser (13) which is permeably connected to the casting chamber only in the region of the rail foot (11), and wherein a reaction pot (1) is provided on the base side with an outflow device which causes a steel melt to flow out of the reaction pot (1) and into the casting mould (4), is configured substantially to obviate turbulent flow conditions inside the casting mould and to homogenise the solidification of an intermediate cast structure between the ends of the rail such that the steel issuing out of the reaction pot (1) after the completion of an alumino-therm