Process for recovering catalyst coating material from a supporting structure, such as, for example, a catalytic converter assembly having a metal mantle, including contacting the catalytic coating material with a sodium, potassium or ammonium hydroxide-containing compound at an elevated temperature; and rinsing with a liquid and filtering the solid catalyst coating material from the solution. Initially, a navigation request is received. A robust, mechanically simple locking apparatus is provided which can be operated without a tool, as well as a correspondingly embodied switching device. A uniform mixing cavity is provided above the nozzle in the flow path of the flame to the nozzle for mixing the hot gases prior to passages through the nozzle. Preferably the leaves are formed by two outer, rigid substrates each laminarly affixed to a respcective inner substrate, the inner substrates being separate sections of the folded circuit medium and the outer substrates being separated sections of a rigid circuit medium.