Process for coating a substrate body
AssigneeUmicore AG & Co. KG
InventorStéphane Masson
Life of this patent
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Abstract
A method of catalytically coating a honeycomb monolith, in particular a so-called flow-through monolith, is featured. The process involves quite precisely coating the monolith with a method that uses an indirect coating via a displacement body. The method included controlling the process by monitoring certain measures and controlling the liquid coating medium feed as to limit bubble formation in the liquid coating medium.
Claims22
A process for applying a washcoat, with a liquid coating medium, to an exhaust gas purification substrate, the substrate having a support body with two end faces and an axial length traversed from the first end face to the second end face by a multiplicity of channels, the process comprising
- supplying the liquid coating medium to the substrate with a liquid supply apparatus that comprises a cylinder containing a displacement liquid and a piston, wherein the displacement liquid in the cylinder communicates with a tank, an interior of the tank having a displacement body arranged in such a way that, when the piston is moved, the displacement body is moved proportionally by the displacement liquid, and the tank communicates with a coating device for the substrate, wherein the displacement body acts on the liquid coating medium, with the result that movement of the displacement body brings about a proportional change in the level of liquid coating medium in the coating device,
- wherein movement of the piston, which leads to an adjustment in the displacement body, is controlled by a control unit that is configured to limit piston velocity as to avoid generation of bubbles in the washcoat.
A coating process for applying a liquid coating medium with a liquid coating apparatus, to form a washcoat on an exhaust gas purification substrate, the substrate having a support body with two end faces and an axial length that is traversed from the first end face to the second end face by a multiplicity of channels, wherein
- the coating apparatus comprises:
- a cylinder comprising a piston and a displacement liquid;
- a tank storing the liquid coating medium, an interior of the tank having a displacement body that is movable by the displacement liquid in the cylinder;
- a coating device adapted for receiving an exhaust gas purification substrate, the coating device being in communication with the tank for directing liquid coating medium from the tank to channels of the exhaust gas purification substrate,
- wherein the coating apparatus is adapted such that movement of the piston causes a movement of the displacement liquid, with movement of the displacement liquid causing an adjustment in the displacement body, with adjustment of the displacement body causing a proportional change in a level of liquid coating medium in the coating device,
- the coating process comprising:
- controlling a backstroke movement of the piston by a control unit configured to limit a velocity of the piston during the backstroke movement as to avoid generation of bubbles in the liquid coating medium stored in the tank.
Dependencies are inferred from the claim text.