| 摘要 |
Process for baking gypsum under superheated steam conditions consisting in stirring the charge in a rotary horizontal cylindrical oven and independently adjusting oven chamber pressure and temperature according to the temperature of the gypsum, the ambient temperature and pressure in said chamber and the charge's mass. The baking process according to the invention provides a high quality beta semihydrate-type plaster with a treatment cycle of less than one hour, and also provides all types of plasters, especially a blend of beta semihydrate and anhydrite II. The oven for carrying out said process includes means for sealing off its ends so that treatment can be carried out under controlled pressure. It also includes at its outlet, a sealed housing (19) with facilities (43) for receiving temperature and pressure sensors and especially a pyrometer (42) inserted into the central part of the oven to monitor the charge's temperature. At the same time that they monitor temperature and pressure, the sensors (13) indicate the evolution of the mass of the charge to be treated. A computer analyzes and processes all this data, adjusting oven chamber pressure and temperature as required, especially according to the type of plaster desired.
|
