Process for densifying porous thin substrates by chemical vapor infiltration and such substrates loading device

For densifying thin porous substrates (1) by chemical vapor infiltration, the invention provides the use of a loading tool (10) comprising a tubular conduit (11) disposed between first and second trays (12 , 13) and around which are arranged radially thin substrates for densification. The tooling thus charged is then disposed inside a reaction chamber (20), an infiltration oven whose reactive gas admission inlet (21) is connected to the tubular conduit (11) to allow the admission of a reactive gas into the conduit which distributes the gas along the main faces of the substrates (1) in a substantially radial flow direction. The reactive gas can also flow in the other direction, that is to say be admitted into the appliance (10) from the outer casing (16) thereof and be discharged through line (it ).