US Patent 11440044 Apparatus and method for coating substrates with washcoats

A substrate coating apparatus comprises a source of a washcoat, a washcoat showerhead comprising a showerhead plate having a plurality of nozzle apertures for discharging the washcoat towards a face of the substrate located below the washcoat showerhead, a conduit fluidly connecting the source of the washcoat to the washcoat showerhead for supplying washcoat to the washcoat showerhead and a partition ring located between the washcoat showerhead and the face of the substrate. The partition ring is dimensioned to be smaller than the face of the substrate and the substrate coating apparatus is configured in use to bring the partition ring into contact with the face of the substrate to thereby define a central region of the face of the substrate which lies within an interior of the partition ring and a peripheral region of the face of the substrate which lies outside the partition ring. The showerhead plate of the washcoat showerhead is configured in use to discharge washcoat onto both the central region and the peripheral region of the face of the substrate.