Patent ID: 7241470

Claim:
A method of controlling a CVI process running in an oven and using a reagent gas containing at least one gaseous hydrocarbon, said process comprising the steps of: setting the operating parameters of the oven, introducing the reagent gas containing at least one gaseous hydrocarbon in the oven, extracting from the oven an effluent gas containing reaction by-products of the reagent gas, including tars, washing the effluent gas with an oil that absorbs tars contained in the effluent gas, the oil being caused to circulate around a closed circuit by taking continuously the oil from a tank so as to be injected into a stream of effluent gas and returning the oil loaded with tars to the tank, providing an information representative of the magnitude of variation over time in the level of oil in the tank, said information being representative of the variation over time in the quantity of tars absorbed by the oil, and controlling the process by modifying at least one of the oven temperature, pressure inside the oven, flow rate of the reagent gas through the oven and composition of the reagent gas when said magnitude drops below a first threshold value or increases to above a second threshold value.