Method of manufacturing a catalysed ceramic wall-flow filter

Abstract

A method of manufacturing a catalysed ceramic wall-flow filter comprising a plurality of channels comprises reducing the pressure in a pore structure of the channel walls relative to the surrounding atmospheric pressure, contacting a surface of the evacuated channel walls with a liquid containing at least one catalyst component or a precursor thereof, whereby the liquid permeates the evacuated channel walls, and drying and calcining the filter containing the catalyst component or its precursor. An apparatus (100) for use in the method comprises means (120) for sealingly isolating a plurality of channels of a ceramic wall-flow filter (14) from the surrounding atmosphere, means (160, 200, 220) for reducing the pressure in the isolated channels to below the surrounding atmospheric pressure thereby to establish a vacuum in the pore structure of the filter walls, at least one reservoir (260) for holding a liquid containing at least one catalyst component or a precursor thereof and means (310, 300, 220) for dosing the isolated and evacuated channels with a pre-determined quantity of the liquid.

Dependencies are inferred from the claim text.