A gas preheater for a CVI furnace designed for the densification of annular porous substrates arranged in a plurality of vertical annular stacks of substrates, comprising: a sleeve made of heat conductive material resting upon the bottom wall of a susceptor and delimiting a gas preheating chamber, with a gas inlet opening in the gas preheating chamber; a heat exchange assembly located in the gas preheating chamber; a gas distribution plate resting upon the sleeve, covering the gas preheating cha...

A method for densification of porous by CVI in which substrates are loaded into a loading zone of an oven and heated to a temperature at which a desired matrix material is formed from a precursor gas(es). A reative gas containing the precursor gas(es) is admitted into the end of the oven and heated upstream from the loading zone of the substrates. The reactive gas is also preheated prior to entering the oven so that, upon entering the oven, it is brought to an intermediate temperature between am...

A sealing box for a chamber for continuously treating a thin strip product, in particular for a furnace for continuously carbonizing a fiber substrate. The sealing box comprises: a longitudinal passage (12) opening out from the box via a first end (12b) for connection to an inlet or an outlet of a treatment chamber (2) and via a second end (12a), opposite from the first; a support surface (14a) inside the passage, on which a strip product (T) can travel between the ends of the box; and static se...

Prior to passing through pumping apparatus effluent gas containing hydrocarbons is subjected to washing by being sprayed with aromatic type oil in oil-recirculating washing apparatus. Polycyclic aromatic hydrocarbons contained in the effluent gas are trapped by being absorbed in the oil. The method is suitable for treating effluent gas coming from an installation for chemical vapor deposition or infiltration using a reagent gas containing a precursor for pyrolytic carbon, or else coming from a c...