FOAM GENERATOR Russian patent published in 1998 - IPC

FIELD: manufacture of building materials; generation of stable foam in manufacture of foam concrete articles. SUBSTANCE: proposed foam generator includes housing with stack of screens, diffuser inlet and outlet branch pipes, preliminary mixing chamber with device for forming foam-air mixture. Cavity of diffuser is filled with fibrous material; preliminary mixing chamber is additionally provided with hollow ring having holes on inner wall in form of nozzles. Device for making foam-air mixture is made in form of turbines: at least two turbines are mounted on one axle in hole of hollow ring for rotation in opposite directions; nozzles are located tangentially or at acute angle relative to tangent line of shroud of each turbine. Branch pipe for feeding the compressed air to turbine is mounted in lower portion of preliminary mixing chamber. Number of screens (V) in stack is chosen from relationship V= Kx+B, where x is size of screen mesh, mm; K is constant coefficient which depends on relationship of screen mesh and number of screens and is equal to 82.7 and B is constant coefficient which is equal to 1. Besides that distance between screens is equal to 1/20 - 1/10 of diameter of housing and blades of turbines are mounted at angle of 45 to 70 deg relative to plane perpendicular to axis of rotation. EFFECT: highly-dispersed homogeneous and stable foam due to intensification of primary foaming owing to optimal number of screens. 3 cl, 2 dwg, 1 tbl