Patent ID: 8464523

Claim:
A regeneration system comprising: a 3-way converter that receives an exhaust gas from an engine; an oxidation catalyst that receives the exhaust gas from the 3-way converter; a particulate matter (PM) filter downstream from the oxidation catalyst and comprising an upstream end to receive the exhaust gas from the oxidation catalyst; an air pump circuit that directs ambient air to the PM filter and not to the 3-way converter, wherein the ambient air is directed to the PM filter via an exhaust conduit connected between the 3-way converter and the oxidation catalyst, wherein the oxidation catalyst is connected between the exhaust conduit and the PM filter; a control module that: determines a temperature of the oxidation catalyst, wherein the oxidation catalyst is downstream from the 3-way converter and upstream from the PM filter; determines a soot loading level of the PM filter; and operates the engine in a rich mode and activates an air pump of the air pump circuit in response to the soot loading level being greater than a predetermined soot loading level and in response to the temperature being greater than a first predetermined temperature; and an air valve of the air pump circuit configured to direct the ambient air into (i) an exhaust manifold of the engine while the air valve is in a first position, and (ii) the exhaust conduit while the air valve is in a second position, wherein the control module: compares the temperature to the first predetermined temperature and a second predetermined temperature, wherein the second predetermined temperature is less than the first predetermined temperature; activates the air pump and adjusts the air valve to the first position in response to the temperature being less than the second predetermined temperature; deactivates the air pump in response to the temperature being (i) greater than the second predetermined temperature, and (ii) less than the first predetermined temperature; and activates the air pump and adjusts the air valve to the second position in response to the temperature being greater than the first predetermined temperature.