<p>The melting unit has: (a) at least one electrode (5) which can be replaced with at least one reaction agent delivery pipe, with the electrode and the delivery pipe passing through the same opening in the lid (4); (b) the unit is rotatable through an angle ( beta ) about a point (19) below the bottom section of the unit; (c) the electrode and delivery pipe are rotatable through an angle ( alpha ) about a point (20) close to the lid (4). Also claimed is an application of the unit.</p>
