| CPC F01N 3/029 (2013.01) [B01D 46/442 (2013.01); B01D 46/448 (2013.01); B01D 46/84 (2022.01); F01N 9/002 (2013.01); F01N 13/009 (2014.06); B01D 2279/30 (2013.01); F01N 3/05 (2013.01); F01N 3/222 (2013.01); F01N 3/225 (2013.01); F01N 3/303 (2013.01); F01N 3/32 (2013.01); F01N 2250/06 (2013.01); F01N 2270/04 (2013.01); F01N 2550/04 (2013.01); F01N 2550/14 (2013.01); F01N 2900/04 (2013.01); F01N 2900/1602 (2013.01); F01N 2900/1606 (2013.01)] | 13 Claims |

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1. An exhaust system for exhausting combustion gases from an internal combustion engine, the exhaust system comprising:
an exhaust conduit for conveying exhaust gases from the internal combustion engine;
a particulate filter for filtering particulates from the exhaust gases conveyed by the exhaust conduit;
a supply inlet arranged to introduce gas into the particulate filter to promote regeneration, the supply inlet being disposed upstream of the particulate filter and downstream of a catalytic convertor;
a control valve for controlling the supply of gas to the particulate filter to control regeneration; and
a controller configured to control the control valve to control regeneration of the particulate filter, the controller being configured to:
determine a particulate loading of the particulate filter; and
output a control signal to control the control valve to control regeneration of the particulate filter in dependence on the determined particulate loading;
wherein the controller is configured to compare the determined particulate loading to a predetermined first loading threshold;
wherein the control signal comprises an open valve request to open the control valve and a fuel cut request to inhibit the supply of fuel to the engine, both in dependence on a determination that the particulate loading is greater than the first loading threshold;
wherein the controller is configured to compare the determined particulate loading to a predetermined second loading threshold, the second loading threshold being greater than zero and less than the first loading threshold;
wherein the control signal comprises a close valve request to close the control valve in dependence on a determination that the particulate loading is less than the second loading threshold; and
wherein the controller is configured to compare the determined particulate loading to a predetermined third loading threshold, and when the determined particulate loading decreases to the third loading threshold or below, to reinstate the supply of fuel to the engine.
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