| 摘要 |
The invention relates to a process and an installation for obtaining cellular concrete and cellular concrete thus obtained that may be used in masonry and thermal and sound insulation works, that may be placed directly or cast into moulds. According to the invention, the process is characterized in that, in the mixing chamber there takes place the introducing of the dry solid components of the mixture, then the communication of this chamber with the environment is stopped and a pressure with a value of - 0.5 ... - 0.2 bar is achieved within the chamber, the vessel being rotated with a rotary speed of 15..48 rpm for 2 ... 6 minutes, then, while continuing the rotation, in the mixing chamber there is introduced air or preferably a mixture containing 1 ... 99% by weight of air and 99 ... 1 % by weight of argon or only argon at a pressure ranging from 1 to 8 bar, preferably of 2.5 ... 5 bar, followed by introducing, at a pressure of 1 ...8 bar, preferably of 2.5...5 bar, a mixture of water and additives comprising the gas entrainer and the organic binders, if the case may be, and continuing the rotation with the same rotary speed of 15 ...48 rpm for 5 ... 15 minutes, then in a discharge chamber there taking place the introducing of the air, at a pressure of 1 ... 8 bar, equal as a value with the pressure in the mixing chamber, then putting the mixing chamber in communication with the discharging chamber, along a path wherein there is provided a pressure equal to the pressure in the mixing chamber and discharging chamber, finally there taking place the gravitational discharging into the mould and equalizing the pressure in the discharge chamber and the pressure in the mixing chamber with the atmospheric pressure, with a view to obtaining the expansion of the gas bubbles attached in the mixture mass by the gas entrainer, and after the expansion, the mixture mass is discharged from the discharging chamber wherein the expansion took place, and it is let to rest for 5 - 10 hours at the atmospheric pressure or in controlled conditions, followed by the said cutting and palletizing operations. The installation claimed by the invention wherein the process is applied has some baffle plates (16) mounted lengthwise of the generatrix of the cylindrical shape of the vessel (2), said baffle plates having a preferably semispherical-shaped cavity (T) located in the direction of rotation of the vessel (2), to a pipe connection (1) secured to a vessel (2) in front of the hole (c) thereof there being secured a nipple (17) of a connecting subassembly (B), in relation with which there is mounted a straightway valve (24), to the lower side of the nipple (17) there being secured an elbow (25) that has a lower portion (k) which partially penetrates in a discharging chamber (a) confined by a lower vessel (23) of a discharging subassembly (C), the elbow (25) having a hole (r) that is closed by a flap (27) articulated to the lower portion (k), in the discharging chamber there being placed on some rollers (28), a mould (30) that can be introduced or withdrawn therefrom through a hole (p) that can be closed by a cover (35) operated by a hydraulic cylinder (33), the upper vessel (2) of a mixing subassembly (A) being sustained by means of the said other bearing (3) to one of said supports (4) by a tubular shaft (37) of a subassembly (E) for modifying the pressure and feeding the water and additives and organic binders, if the case maybe. Cellular concrete obtained according to the invention, by applying the process within the installation, is constituted by a mixture consisting of 48 ... 62% of 0 - 1 mm grain size sand, 48 ... 30% Portland cement with or free of additions consisting of ash and slag, 27 ... 18% water, 0.5 ... 0.08 AAS, 1 ... 0.6% addition consisting of clay, these values being related to one cubic meter, this cellular concrete having a water absorption of 18 ... 10%, a thermal conductivity of 0.06 ... 0.12% WVm0K and a compression strength of 2.4 ... 8.2 N/mm2, these values being obtained in the conditions in which the homogenizing pressure is of - 0.5... - 0.2 bar, the homogenizing time of 4... 3 minutes, there being used a mixture consisting of argon and air in a 3... 1 or 1/1 ratio, a mixing pressure of 2.5 ... 5 bar and a mixing time of 5 ... 15 minutes, there being obtained a concrete with a volume weight ranging from 400 to 900 kg/m3. |
