Patent ID: 7235218

Claim:
A compact catalytic reactor comprising a plurality of metal sheets arranged as a stack and bonded together, the stack defining a plurality of first flow channels for a first fluid alternating in the stack with a plurality of second flow channels for a second fluid so as to ensure good thermal contact between the first and the second fluids, each flow channel being defined between a respective pair of adjacent sheets; each flow channel in which a chemical reaction is to take place extending straight through the stack and containing a removable gas-permeable catalyst structure incorporating a metal substrate; and an inlet and an outlet for the first fluid; the first flow channels being oriented in a direction that is perpendicular to that of the second flow channels; characterised in that between successive second flow channels in the stack the reactor defines at least three first flow paths each defined by a plurality of side-by-side first flow channels; and the reactor incorporates flow diversion means such that the first fluid must flow through at least three first flow paths in succession, in flowing from the inlet to the outlet; the flow diversion means comprising linking means within the stack that allow fluid flow between end portions of successive flow paths in a direction generally transverse to that of the first flow channels, so the flows in successive flow paths are in opposite directions.