{
  "$type": "site.standard.document",
  "description": "In an exhaust gas purifying system (1) for removing NOx by a NOx occlusion reduction type catalyst (11) for exhaust gas of an internal combustion engine, the air-fuel ratio in the exhaust gas is controlled by setting the target air-fuel ratio at a predetermined first air-fuel ratio which is a rich…",
  "path": "/patents/1077860",
  "publishedAt": "2005-05-11T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B01D53/9495",
    "ISUZU MOTORS LTD [JP]"
  ],
  "textContent": "In an exhaust gas purifying system (1) for removing NOx by a NOx occlusion reduction type catalyst (11) for exhaust gas of an internal combustion engine, the air-fuel ratio in the exhaust gas is controlled by setting the target air-fuel ratio at a predetermined first air-fuel ratio which is a rich air-fuel ratio by a sulfur purge control means (C24) after the start of sulfur purge, and thereafter, the air-fuel ratio in the exhaust gas is controlled by changing the target air-fuel ratio to the predetermined second air-fuel ratio which is a stoichiometric air-fuel ratio, when the oxygen concentration (Od) in the downstream of the NOx occlusion reduction type catalyst (11) measured by an oxygen concentration detection means (C12) becomes lower than a predetermined threshold. Thereby, sulfur component accumulated in the NOx occlusion reduction type catalyst (11) can be purged efficiently, while preventing carbon monoxide from being discharged into the atmospheric air.",
  "title": "Sulfur purge control method and exhaust gas purifying system"
}