METHOD AND APPARATUS FOR QUENCHING PIPES

1385243 Quenching tubes MANNESMANN AG 28 Jan 1972 [1 Feb 1971] 4226/72 Heading C7N A steel tube is quench-hardened by heating the tube to its autentitizing temperature and quenching in a horizontal position by applying quenching medium to the external and internal surfaces while the tube is rotated so that a point thereon is moved helically about the tube axis. The quantity of quench medium applied per unit area to the internal surface is at most half as much as that applied externally and an axial air flow towards the quenched end of the tube is produced by the flow of quenching medium itself. As shown quenching is effected by internal and external nozzle rings 5 and 4 to tube 2 which has been heated in furnace 1. Internal ring 5 has attached cylindrical means 12 providing a narrow annular space 16 in which air flow is induced by the flow of quenching medium. This air flow may be assisted by compressed air from nozzle 17. Support means 8, 9, 14, 15 centralize the internal quench head during its passage along the tube.