Abstract: A method and apparatus for the acoustic examination of a monolith for damage, wherein a blow of defined force is applied by a hard striker to a monolith for its acoustic examination for damage. The sound pressure distribution over a predetermined frequency range, of the sound radiated by the struck monolith is analyzed by a frequency analyzer and the result is compared with a reference curve defined for undamaged monoliths. The device for implementing the process has a receptacle for the monolith to be examined, a striker, capacitor microphones as the sound pressure receivers and an evaluation unit with a frequency analyzer.

Abstract: A method and apparatus for cleaning of a soot filter in the exhaust line of a diesel engine with a combustion chamber placed in front of the soot filter where a fuel nozzle and an adapted electrical ignition mechanism is built in thereby enabling an after burning of the exhaust without secondary air. The exhaust in the combustion-chamber is mixed with the fuel, which is injected through the fuel nozzle, and ignited by an ignition-device with the existing portion of the unburned oxygen. The hot exhaust effects the burn down of the accumulated soot in the soot filter.

Abstract: In a process for the automatic regeneration of a soot filter in an exhaust line (11) of a diesel engine in a passenger vehicle, a throttle valve in the intake line is controlled by the following system logic. The speed (n) of the diesel engine (1), the back pressure (PVF), measured upstream of the soot filter (12), and the exhaust temperature are each compared with preset lower limit values (ng, PGU, TGU). The back pressure (PVF) is additionally compared with a preset upper limit value (PGO). When all measured variables lie above the limit values mentioned, the control device generates a signal "close throttle valve". The two limit values for the pressure, (PGU and PGO), are displaced with the speed (n) in accordance with their respective alteration.

Abstract: A method for regenerating a soot filter of internal combustion engines, especially of diesel intenal combustion engines, and apparatus for carrying out the method in which a soot burning-off operation if initiated in predetemined intervals; the intervals are determined by an operating parameter of the internal combustion engine itself which results from the sum of a characteristic magnitude variable toward both sides.

Abstract: A burner for cleaning accumulated soot from a soot filter associated with the exhaust of internal combustion engines, the burner is simple from a constructional viewpoint and especially effective with respect to initiation and maintenance of a soot-burning process in the soot filter. The burner includes a fuel nozzle, air nozzle, and glow plug arranged in a predetermined succession in the flow direction of the air introduced into the burner chamber. An especially intensive intermingling of the fuel-air mixture for the burner and/or for the soot filter is obtained by producing a turbulent flow by means of the air nozzle.