Process for the coating of the flow channels of a honeycomb form catalytic converter carrier with a dispersion coating

A process for coating a cylindrical, monolithic honeycomb-form catalyst carrier with a coating dispersion, said carrier having axially aligned flow channels arranged in a grid over its cross sectional area, said carrier having an upper and a bottom face, and said process comprising the steps of:

• a) bringing said carrier in an upright position so as to orient the flow channels vertically;
• b) filling said flow channels through the bottom face with a volume of said coating dispersion which is about 10% greater than the empty volume of the flow channels, so that after completion of the filling cycle said upper face is flooded by the coating dispersion;
• c) removing excess coating dispersion from the upper face of said carrier;
• d) emptying and clearance extraction of the flow channels through an extraction impulse, which is generated by connecting a vacuum tank via an extraction conduit with the bottom face of the catalyst carrier, whereby the time between the beginning of the fill cycle and the end of the emptying and clearance extraction amounts to no more than about 5 seconds, and optionally drying and calcining the coated catalyst carrier after said emptying and clearance extraction of the flow channels.