Treatment of particulate filters
AssigneeJohnson Matthey Public Limited Company
InventorsSabina Burmester, Thomas Hotchkiss, David Marvell, John Turner
Life of this patent
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Abstract
A method and apparatus (1) for treating a filter (2) for filtering particulate matter from exhaust gas. A reservoir (3) containing a dry powder (4) is provided. A vacuum generator (6) establishes a primary gas flow through a porous structure of the filter (2) by applying a pressure reduction to an outlet face of the filter (2). A spray device (7) receives the dry powder (4) from a transport device (8) and sprays the dry powder (4) towards the inlet face of the filter (2). A controller (9) is configured to control operation of at least the vacuum generator (6) and the spray device (7).
Claims13
A method for treating a filter for filtering particulate matter from exhaust gas, the method comprising the steps of:
- a) containing a dry powder in a reservoir;
- b) locating a filter in a filter holder, the filter comprising a porous substrate having an inlet face and an outlet face, the inlet face and the outlet face being separated by a porous structure;
- c) establishing a primary gas flow through the porous structure of the filter by applying a pressure reduction to the outlet face of the filter;
- d) transferring the dry powder from the reservoir to a spray device located upstream of the inlet face of the filter;
- and
- e) spraying the dry powder, using the spray device, towards the inlet face of the filter such that the dry powder is entrained in the primary gas flow and passes through the inlet face of the filter to contact the porous structure;
- wherein the method further comprises monitoring a back pressure of the filter during at least step e) and stopping the spraying of the dry powder towards the inlet face of the filter when a pre-determined back pressure of the filter is reached.
Dependencies are inferred from the claim text.