AUTOMATIC TRANSFER LINE FOR THERMOCHEMICAL TREATMENT OF PIPE INTERNAL SURFACE Russian patent published in 2000 - IPC

FIELD: thermochemical treatment of hollow articles, particularly, induction plants for gas carburizing of metal of pipe internal surface with their continuous successive heating in horizontal position. SUBSTANCE: automatic transfer line for thermochemical treatment of pipe internal surface with induction heating in horizontal position has setting and receiving roller conveyers, induction heater and induction thermostat, intermediate supporting drive rollers installed between them, system of supply of carborizing gas to pipe and withdrawal of spent gases, circular sprayer, circular resistor furnace installed coaxially to induction thermostat and apparatuses for monitoring of pipe heating temperature. Intermediate supporting rollers and rollers of roller conveyers are installed for turning round vertical axis and located on higher levers for motion perpendicular to longitudinal axis of transfer line. Rollers have individual rotary drives and provided with thyristor asynchronous controlled electric drive for matching of rollers rotation speed electrically connected with apparatuses for monitoring of pipe heating. System for supply of carburizing gas and withdrawal of spent gases from pipe is provided with three-way switch of gas supply direction and removable plugs installed in pipe ends. In addition, transfer line is equipped with local stationary exhaust ventilation over entire transfer line length. EFFECT: stabilized process parameters of conditions of gas carburizing and carbonitriding, and higher quality of articles. 2 cl, 2 dwg