Method for hardening form substances of building materials containing binding agents and autoclave for the execution of the method
First Claim
1. A method for hardening form substance of building material containing binding agents inside a pressure chamber of an autoclave, comprising conveying a gaseous heating medium to said autoclave, increasing the temperature of the building materials in said autoclave to a given upper limit during a heating-up phase, increasing the pressure within said autoclave above atmospheric pressure and at a pressure which precludes evaporation of water during said heating phase such as to prevent exposure of the form substances in the autoclave to evaporated wet vapor during the heating-up phase, maintaining the temperature in the autoclave at least until a given equalization temperature is reached on the inside of the form substances during a holding phase, maintaining the pressure within said autoclave above atmospheric pressure and at a pressure which precludes evaporation of the water during said holding phase such as to prevent exposure of the form substance in the autoclave to evaporated vapor during the holding phase, said steps of increasing the temperature and the pressure and maintaining the temperature and the pressure resulting in producing in said autoclave a temperature/pressure condition which precludes evaporation of water within the autoclave during said heating-up phase and said holding phase, subsequently reducing the temperature during a cooling-down phase to an expulsion temperature, and reducing the pressure in said autoclave during said cooling-down phase to atmospheric pressure, whereby the form substances are precluded from being exposed to evaported water vapor during the hardening thereof in the autoclave.
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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. However, in order to produce form substances of a low water content economically, according to the present invention, on the one hand, steam is replaced by gas which is maintained below the evaporation temperature of water through sufficient increase in pressure, and, on the other hand, as a replacement or complement, heat is conveyed to the inside of the pressure chamber before the cooling-down phase and an increase in the temperature of the steam beyond the given limit value is prevented by blowing off steam, thereby attaining an integrated drying process.
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30 Claims
- 1. A method for hardening form substance of building material containing binding agents inside a pressure chamber of an autoclave, comprising conveying a gaseous heating medium to said autoclave, increasing the temperature of the building materials in said autoclave to a given upper limit during a heating-up phase, increasing the pressure within said autoclave above atmospheric pressure and at a pressure which precludes evaporation of water during said heating phase such as to prevent exposure of the form substances in the autoclave to evaporated wet vapor during the heating-up phase, maintaining the temperature in the autoclave at least until a given equalization temperature is reached on the inside of the form substances during a holding phase, maintaining the pressure within said autoclave above atmospheric pressure and at a pressure which precludes evaporation of the water during said holding phase such as to prevent exposure of the form substance in the autoclave to evaporated vapor during the holding phase, said steps of increasing the temperature and the pressure and maintaining the temperature and the pressure resulting in producing in said autoclave a temperature/pressure condition which precludes evaporation of water within the autoclave during said heating-up phase and said holding phase, subsequently reducing the temperature during a cooling-down phase to an expulsion temperature, and reducing the pressure in said autoclave during said cooling-down phase to atmospheric pressure, whereby the form substances are precluded from being exposed to evaported water vapor during the hardening thereof in the autoclave.
- 22. Apparatus for hardening form substances of building materials containing binding agents, comprising an autoclave having a pressure chamber for receiving said form substances, conduit means for conveying a gaseous medium to said pressure chamber, heating/pressurizing means for heating said autoclave to a given upper limit and to pressurize said autoclave to a pressure above atmospheric pressure to a pressure which precludes evaporation of water during a heating-up phase such as to prevent exposure of the form substances in the autoclave to evaporated wet vapor during said heating-up phase, said heating/pressurizing means being operable to maintain the temperature and pressure within said autoclave at a temperature/pressure condition which precludes evaporation of water in the autoclave during a holding phase, said heating/pressurizing means maintaining said temperature/pressure condition until an equalization temperature is reached on the inside of said form substances, and reducing means for reducing the temperature and pressure within the autoclave to ambient conditions during a cooling-down phase, whereby the form substances are precluded from being exposed to evaporated water during the hardening thereof in the autoclave.
Specification