METHOD OF FOAM CONCRETE MIXING AND DEVICE FOR ITS EMBODIMENT Russian patent published in 2000 - IPC

FIELD: civil engineering. SUBSTANCE: method of foam concrete mixing includes mixing by portions in fixed-drum concrete mixer of initial mortar with air-mechanical foam produced by foam generator from water, compressed air, foaming agent, surfactant and obtaining of foam concrete by forced mixing of initial mortar, air-mechanical foam and water. Portion mixing in fixed-drum concrete mixer is effected by supply of initial mortar, mainly, with density from 1700 to 1850 kg/cu.m and simultaneous supply from foam generator aerator, through portable hose with extension and pipes with nozzles of air-mechanical foam with expansion degree from 8 to 60 and stability for at least 1 h. Foam is supplied into mixer by two ways: from top to bottom through hose extension and from bottom upward through pipes with nozzles under regulated pressure of compressed air from measuring receiver and foam generator aerator. When required, water is supplied to the same mixer. Initial mortar, foam and water are mixed in fixed-drum concrete mixer to obtain homogeneous foam concrete with preset density from 450 to 1400 kg/cu.m depending on regulated concentration of mortar, foam and water. Upon completion of portion mixing of foam concrete, the whole system is washed to remove residual foam concrete, foam and foaming agent with the help of water from measuring receiver under pressure of compressed air. Water after washing is gathered into special vessel for it repeated use. The device for method embodiment has foam generator, aerator, water measuring device, foaming agent and mixer. The device for foam concrete mixing is located in housing and may be moved. Housing has locked doors. Housing compartments accommodate foam generator with vessels for foaming liquid and pure water for washing of whole system, measuring receiver operating under pressure up to 8 kgf/sq.m, aerator for foam preparation, compressor with electric motor, safety and control valves, pressure gage, controlled shutoff valves, pipelines, hoses, control panel, compartment for storage of tools and spare parts, fixed drum concrete mixer and pump for supply of foam concrete through pipelines to user. Installed on bottom of fixed-drum concrete mixer are pipes with nozzles for foam supply to mixer from bottom upward. Movable portable hose with extension for supply of foam to mixer from top to bottom under pressure of compressed air from measuring receiver and aerator is installed in mixer upper part. Invention provides for production of foam within wide range of its expansion degree and density. EFFECT: higher efficiency of method and improved design of device. 7 cl, 4 dwg, 7 ex