A device for separating welding-material burrs from an aluminothermically produced welded joint for rails consists of an assembly of shearing shoes (5, 6), actuatable by hydraulic fluid and designed to shear off welding-material burrs, at least in the region of the rail head, one of said shearing shoes (5) being fastened to a guide carrier (7) that can be slid in a longitudinal direction of a frame (21), in the direction of arrow (11), by means of two piston-cylinder units (8, 9) that can be pressurised on both sides, and a battery-operated servomotor (15) designed to actuate the piston-cylinder units (8, 9) being fastened to the frame (21), said servomotor being actuatable by a control valve (10). The control valve (10) is equipped with a manually-operable switching member.
The invention relates to a preheating torch which is intended to prepare an aluminothermic weld of two rail ends spaced apart from each other at the end faces by a welding gap and which is designed for convenient operation on the laid track. Said torch consists of a housing (1), which accommodates means for forming a combustible mixture, and an outlet nozzle (6), which is intended to introduce the combustible mixture into a region to be preheated, on the end of a tubular element (4), wherein a fan is provided inside the housing (1) to supply said means with combustion air taken from the ambient atmosphere. The housing (1) is also provided with supports (2, 3) for placing on the ground on either side of the rail ends to be welded and with an annular body (10) acting as a crane eye.
F23D 14/36 - Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air in which the compressor and burner form a single unit
F23D 99/00 - Subject matter not provided for in other groups of this subclass
E01B 29/44 - Methods for effecting joining of rails in the track, e.g. taking account of ambient temperature
For the permanent closure of drilled holes at a chosen location, there is proposed a method in which a support structure is first created at that location, onto which support structure a cast body is formed by means of a first aluminothermic process, a retardant being added to the reactants of this process, the cast body sealing and closing the drilled hole and serving as a substrate for the main reaction, involving a second aluminothermic process, for creating the permanent closure. The material nature of the cast body makes it able to withstand the thermal and mechanical stresses of the main reaction, and in particular to reliably prevent the thermite melt running into the drilled hole.
In order to reduce the strain on the accumulator (5) of a device for igniting an aluminothermic mixture (11) with a view to better energy use, a circuit arrangement is provided for regulating the current between the electrodes that are introduced into the mixture (11), in which circuit arrangement the current between the electrodes is continuously measured, wherein low-frequency sampling of the current profile is performed in a first channel (17) in order to continuously regulate the current, and high-frequency sampling of the current profile is performed in a second channel (19) for early detection of the onset of ignition of the mixture (11) and/or of a short-circuit. A signal is derived from the detection of the ignition and is used to limit or lower the current. The current regulation thus restricts the inflow of energy into the mixture (11) to a necessary level.
A reaction crucible (1) intended for carrying out aluminothermic welding operations is provided with a bottom (20) having an outflow opening (4) and contains a fine-grain aluminothermic mixture. In order to retain the slag (7) formed as a reaction product of the aluminothermic reaction in the reaction crucible (1), there is provided a shutoff element (10), the density of which is greater than that of the slag (7) and less than that of the molten steel (6), wherein the shutoff element (10) is incorporated into said mixture. The shutoff element (10) consists of a shell (11) which surrounds a filling (12) that consists of a metallic solid body, such that the latter does not prevent the steel (6) from flowing out and only comes into operation once the steel (6) has passed out of the reaction crucible and the outflow opening (4) has been closed by the shutoff element (10).
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.
