A method for slicing a workpiece into wafers in which a polyphosphate solution is applied to the workpiece during the slicing process. The currency bills are denominated by the document processing device, and the total value of the bills included in each deposit is accumulated. A lambda probe detects a value characteristic of an exhaust-gas lambda number upstream of the 3-way catalytic converter, and transmits said value to an engine control unit with an integrated PI or PID regulator. A mixing surface may be coupled with the perforated barrier which may define a path within the exhaust stream to impart a swirl to the exhaust stream.