| 摘要 |
A combustion box exhaust filtration system and method which removes both particulate matter (PM) and unburned hydrocarbons (UHC) from the exhaust gases. Two filters in parallel are used, each alternating operation as the other regenerates. Each filter is preferred to be constructed in a conventional manner and operates at between 100 to 300 degrees Centigrade. A microprocessor controlled valve system regulates which filter is active and which is regenerating and/or inactive. PM accumulates at the active filter, with UHC condensing on the PM. Accordingly, only PM and UHC free gasses pass out the exhaust. When the active filter becomes clogged, the microprocessor switches it to inactive status, and switches the other filter to active status. Regeneration of the inactive filter is initiated by the microprocessor using a glow plug at a predetermined location in the filter, in which PM and UHC burn slowly across the entire filter. A recirculation conduit provides for the gases produced by the resulting slow regeneration to be directed to the air intake of the combustion box. Any remaining UHC or PM will be subsequently burned in the combustion box. When regeneration has completed, the inactive filter will await being switched by the microprocessor to active status when the other filter has become sufficiently clogged that it is time for the microprocessor to switch it inactive and thereafter initiate its regeneration.
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