Patent ID: 7111672

Claim:
A heat exchanger or fluid mixing means comprising a bonded stack of plates, the stack comprising at least one group of plates, comprising one or more perforated plates ( 50 ) sandwiched between a pair of primary separator plates, each perforated plate has a plurality of perforations arranged in rows across the plate in a first direction, with a land between each adjacent pair of perforations in a row and with ribs ( 54 ) between adjacent rows, the lands forming barriers to flow in the first direction across the plate and the ribs forming barriers to flow in a second direction across the plate, the second direction being normal to the first direction, the ribs ( 54 ) having vents ( 56 ) through a portion of their thickness, the vents extending from one side of a rib to the other side in the second direction, whereby flow channels are provided through the vents and the flow channels defined by the perforations lying between each adjacent pair of lands provide a flow passage to cross the plates in the second direction, wherein a deposit of catalytic material is retained within the passageways of the said at least one group of plates.