| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an exhaust gas treating method preventing overheating of a nitrogen oxide purifying device in a process of eliminating sulfur compounds in the nitrogen oxide purifying device during regeneration of a particulate matter filtering device.SOLUTION: The exhaust gas after-treating method according to an embodiment of the invention may include the steps of: determining a regeneration condition of the particulate matter filtering device; eliminating collected soot to a preset amount by raising exhaust gas to a first preset temperature to regenerate the particulate matter filtering device; controlling exhaust gas flowing into the nitrogen oxide purifying device into a lean condition while the particulate matter filtering device is regenerated; after maintaining the lean condition, eliminating sulfur components in the nitrogen oxide purifying device by controlling exhaust gas, which flows into the nitrogen oxide purifying device, into a rich condition again; and repeating the lean condition and the rich condition to complete the regeneration of the particulate matter filtering device or to complete the elimination of the sulfur components in the nitrogen oxide purifying device.</p> |
