Secondary containment for a perforated plate

An apparatus for the secondary containment of catalyst comprising:

• a standoff screen having an open area, wherein the standoff screen is affixed to a screenless reactor partition by a plurality of standoff supports wherein the screenless reactor partition comprises:
• a partition having apertures defined therein, wherein each aperture has an upper edge and a lower edge;
• and
• a plurality of louvers and wherein each louver has an upper edge and a lower edge and the louver is affixed to the partition at a position above the upper edge of an aperture, and extends away from the partition at an angle between about 1 degree and about 85 degrees, and where the louver lower edge extends to at least the lower edge of the aperture and wherein the louvers further comprise vanes extending substantially perpendicularly from the louvers, and affixed to the underside of the louvers at a position between about 10% and 90% of the length of the louver.