Abstract: A method of autoclaving porous piece-goods, by steam under pressure, wherein the autoclaving operation includes sequential phases of heating with steam, holding, and then relaxing the pressure and temperature, wherein the holding phase includes a drying process. In order to obtain as dry a product as possible with the smallest possible energy input, it is provided that a drying process is carried out within the holding phase in which the autoclave is heated more than to compensate for heat losses and to a temperature above the temperature of vaporization of the water so that the material is dried by controlled discharge of steam from the interior of the autoclave. The steam discharged from one or more autoclaves during the drying process is used to heat up at least partially an autoclave to be heated.

Abstract: An autoclave for treating charged materials (6) with vapor under pressure, with a substantially cylindrical inner chamber (2) surrounded by an autoclave casing (1) and with a heating device (8) responsive to a heated heat transfer medium to generate vapor in the inner chamber (2). In order to provide the heating in a way which is favorable structurally and in terms of energy, it is provided that the heating device (8) is arranged within one of the curved side regions of the autoclave casing (1), and consists of at least one flue (10) arranged substantially vertically in the autoclave and a heat exchanger (11) arranged in the lower inflow region of the flue (10) and through which flows a heat transfer medium, so that a convection flow results circulating substantially in the circumferential direction of the casing (1) of the autoclave.

Abstract: The method relates to the hardening of form substances made of building materials and containing binding agents in a pressure chamber of an autoclave to which is conveyed a gaseous heating medium, the temperature of which is increased during a heating-up phase up to a given upper limit value. During a holding phase, the temperature is maintained at least until a given equalization temperature is reached on the inside of the form substances. Subsequently, during a cooling-down phase, the temperature is reduced by reducing the pressure to the expulsion temperature. Porous light building materials in a conventional process would absorb a high amount of water through the condensation of water resulting from steam having been conveyed into the autoclave for the purpose of hardening.