A process for the chemical vapor infiltration of at least one refractory material

A process for the chemical vapor infiltration of at least one refractory material, in which process in a reaction zone a porous structure with a gaseous precursor containing at least gas-flow-type, wherein a gaseous precursor and the residence time τ of the gas in the reaction zone at a given temperature in the reaction zone the partial pressure of at least set so that takes place in the porous structure of a deposition reaction of the precursor in the partial pressure range of the saturation adsorption, whereby saturation adsorption means that the deposition rate remains constant at an increase in the partial pressure of the gaseous precursor or is insignificantly increased, and reacting a gaseous precursor is limited at any stage of infiltration as the least, that it flows through the reaction zone not more than 50%, preferably 10% to 25%, of the fed in gas, a solid phase forming at least one gaseous precursor as a solid phase are deposited in the porous structure, and the energization of the porous structure in a cylinder disposed in the vertical direction between an inlet side and an outlet side of the reaction zone stack of superposed annular layers by vertical circumferential gaps (A, B) each having a constant gap width of a radially outer circumferential gap (A) disposed radially inwardly from the outer peripheral edges of the layers is limited and is radially bounded outwardly from a reactor wall, and a radially inner circumferential gap (B) which is radially delimited outwardly from the inner circumferential edges of the layers and is radially inwardly bounded by a reactor core as well as between the layers transverse to the is vertical direction extending transverse gaps (C) to the peripheral columns (a, B) are open, with the circumferential gaps have a gap width which is constant in each case in the circumferential direction of the stack, and the ratio of the gap width of the radially inner circumferential gap (B) to the gap width of the radially outer Umf angsspaltes (A) is greater than 1 and less than or equal to 20 and the ratio of the gap width of each of said lateral column (C) to the gap width of the radially outer circumferential gap from 0.25 to 12, wherein the radially outer circumferential gap ...