AIR CURRENT CHANGEOVER SWITCH Russian patent published in 1997 - IPC

FIELD: mining industry; applicable in reversing of air current and changing over of the working and standby fans in ventilation plants with centrifugal double-suction fans. SUBSTANCE: air current changeover switch includes body connected with atmosphere, suction and pressure branch pipes for connection with working and standby fans to body holes, whose centers are located over the circumference, air distributor having branch in form of box with guide vanes and connected with mine ventilation duct, blind valve attached to branch, shaft installed in rotary bearings. Body of changeover switch has flexible cover plates secured over periphery of holes and secured to edges of inlet of air distributor branch is shutoff member of curvature variable radius. Outlet of air distributor is sealed with cover plate. Pulley is installed for transmission of rotation by drive. Besides, body of the changeover switch has two side walls and rear wall and overhead cover forming chamber communicated with atmosphere through hole and also through air heater (in pressure fan plants) or noise suppressor (in suction fan plants). Reversing of air current in fans, served by changeover switch, is accomplished by turning the air distributor together with branch from one hole to the other one, to which given fan is connected. To change over from the working fan to the standby fan, the branch is turned to one of hole of standby fan. Fan is started by closing one of holes by means of valve. Static balancing of the branch in rotation of air distributor is ensured by the valve due to its respective weight. EFFECT: high space saving, strength and reliability, reduced metal content and extended range of application of air current changeover switch. 2 cl, 7 dwg