Modular fuel cell cassette spacers for forming a solid-oxide fuel cell stack

In a modular fuel cell cassette for forming a fuel cell stack, anode openings in the mounting plate and separator plate are separated and connected by modular spacer rings such that the cassette is incompressible at operating temperatures and compressive loads within the stack. The spacer rings are formed in modules wherein all of the rings required for all of the anode supply chimneys or all of the anode exhaust chimneys of any given cassette are ganged together and include a perimeter rail to which the rings are connected which automatically orients and positions the rings within the cassette during assembly thereof. The present invention eliminates the prior art need for individually positioning and spot welding each prior art ring in place prior to assembly of a prior art cassette. Two different structural embodiments for a spacer ring module are disclosed.