A filter-cleaning apparatus utilizes pulsed air to remove matter collected on first surface of a filter. The pulses are directed at the filter with a controlled shape and time to optimize reverse pulsing. Reverse flow loosens the material which is collected in a hopper on the upstream side of the filter. The collected matter then being combusted in the hopper so that the amount of material collected is minimized. Pulsing occurs while the thermal exhaust flow continues so that operation of the engine is not interrupted. A number of valves may be utilized to clean one or more filters.