Resistance heating of rolled products, esp. steel tubes - using contact clamps travelling with the continuously moving tube

摘要

The steel tubes are travelling continuously in a straight path, and rows of electric contacts are mounted on supports which move a limited distance in the same direction as the tube being heated. Two sets of contacts are used and, while one set is clamped to the tube and moving forward with it, the other set is disengaged and moving back to its starting position from where it is used to transmit the current while the first set returns to its initial position. Clamps are used which open for the return travel after the current has been switched off so not arcing occurs and the pref. system uses three sets of contacts, each being connected to one phase, of a three phase supply. Provides continuous, uniform heating of the entire tube without wear of the contact surfaces.