Hydro-quebec

Hyun K Choi

Michel G Drouet

Jean Meunier

A water-cooled plasma torch specially designed to drill into a refractory material is used in a method for opening a tap hole closed by a plug in a wall of a furnace. This method which is particularly well adapted for robotization, includes the step of melting and breaking up the plug closing the tap hole by means of a jet of swirling gas of high speed and high temperature, generated by the plasma torch. The main advantage of this method is that the stream of plasma gas leaving the torch has a well defined outline ensuring precise and reproducible tapping of the plug and, as a result, efficient closing of the tap hole with a new plug after the furnace has been emptied.

Use of a plasma torch to open a tap hole in a metal furnace

Disclosed is a plasma reactor for use to treat ores or other material at a very high temperature in order to physically or chemically transform the same. The reactor comprises a vertical, electrically insulated sleeve disposed at the upper end with a hollow torch of a conventional structure, for use to generate a plasma column. A gas is tangentially injected into the torch to create a vortex inside the same. The material to be treated is dropped, in powder form, vertically downward inside the sleeve from the upper end thereof, beside the hollow torch, so as to form a substantially uniform cylindrical curtain of particles falling down into the sleeve. The particles that are centrifugally projected against the internal wall of the sleeve by the vortex escaping from the hollow torch, entirely cover the internal wall of the sleeve and shield, while simultaneously being treated by heat generated by the plasma arc column. The reactor further comprises a crucible positioned under the sleeve to collect the treated particles in molten form, which drip down from the sleeve at the lower end thereof. The plasma column may be generated by the hollow torch exclusively, when the reactor is intended to be used in a non-transferred arc mode. The reactor may also be used in a transferred arc mode. In such a case, the arc is transferred to a melt contained in the crucible. Another electrode is provided for this purpose at the bottom of this crucible, and is electrically connected to the power supply.

Growing community of inventors

St Lambert, Canada

Hyun K Choi