Patent RU-2262497-C2 (RU)
Inventor: ZUBEKHIN S A
IPC: C04B38/00
Filed: 2003-12-15
Granted: 2005-10-20
Abstract: FIELD: construction materials industry; methods of production of foam concrete. 
     SUBSTANCE: the invention is pertaining to the field of construction materials and products, in particular, to foam concrete (FC) and methods of its production. The technical result is an increase of a homogeneity and strength of foam concrete, a decrease of its density, provision of a stable mode of its operation and a durable operational service life. The method of FC manufacture provides for a two-stage stirring of the initial components with production at the first stage of a cement-water suspension (CWS) in the field of the centrifugal force, its homogenization - at the second stage with a previously prepared foam (F) at limitation of access of atmospheric carbonic acid till formation in FC of the cement hydratation products mainly free from inorganic carbonates according to the criterion of availability of AFm-phases, and transportation of the produced FC mixture of the given density into a form or a formwork with its consequent solidification. The CWS stirring at the 1 stage realize using a cavitation intensified by additional blowing of CWS with its babbling by the compressed air under the pressure of 250-600 kPa at the level of its dynamic viscosity of 8-15 Pa·s and binding of the present in it carbonic acid by hydrolytic lime separable by the cement at a degree of an initial hydratation of the cement at the end of stirring at 1 stage according to a criterion of other useful impurities - 4.5-11 mass %, and in the end of homogenization - 6.5-15 mass %. The installation for production of FC contains an express mixer for preparation of CWS made with a rabble located in the cylindrical chamber on the vertical shaft and made in the form of a rotor of the open turbine with the radially - arc-shaped blades on a disk in a cantilever way fixed on the shaft of the lower drive and facing the bottom of the chamber and supplied with a stuffing box with a seal for the shaft located in a central hole of the bottom with an annular gap, using which the cavity of the box is linked with an inlet pipeline of the compressed air, communicates with the working space of the chamber, at the ratio of  the areas of cross-sections in the clear chamber and a positive allowance of 3500-75500, a hatch for feeding the initial components into the chamber and an unloading connecting pipe with the gate tangentially connected with the chamber, the single-shaft low speed concrete mixer supplied with a single shaft slow concrete mixer equipped with the reversing drive and with a working tool on the horizontal power-driven shaft located in the body with the butt walls and the connecting pipes of loading of CWS and F and made out of the fixed in its longitudinal diametric planes T-shaped, in pairs alternating and mutually oppositely directed vanes and connected with the shaft by radial spokes a spiral band divided into 3 sections, from which the tail sections have the right-sided, and the middle sections - the left-sided directions of coils with a ratio of lengths of the sections of (4-7) : (2-4) : (1-2), counting from the butt wall towards the connecting pipe with the gate for unloading FC mixtures linked by means of the pipeline with the screw pump, and the foam generator having the inlet pipeline of the compressed air and the pipeline of F. At that the unloading connection pipe of the express mixer is connected by a pipeline with an inlet connection pipe in the bottom part of the body of the concrete mixer under the middle section of the band, and the pipeline F is above it. The invention is developed in the dependent points. 
     EFFECT: the invention ensures increased homogeneity and strength of foam concrete, decreased its density, a stable mode of operation, a durable operational service life of the equipment. 
     27 cl, 1 ex, 3 tbl, 3 dwg