RECIRCULATION AIR CURTAIN Russian patent published in 2003 - IPC

FIELD: industrial ventilation systems, possibly air screening of door ports in walls of industrial rooms. SUBSTANCE: recirculation air curtain for closing port in wall with double doors includes ventilation unit arranged at one side of port and having receiving and discharging vertical slit nozzles joined respectively with suction and delivery branch pipes of blower. Discharging vertical slit nozzle is arranged in space between doors at side of port and it is inclined by acute angle to plane of port. There are dividing screens and guiding boards secured to lateral walls of space between doors in slit of discharging nozzle. The last is provided with flap kinematically joined with one of guiding boards. Said boards are curvilinear with curvature radius equal to width of port and they are secured to lateral walls of space between doors with possibility of closing said space. Boards are made of composite polymeric material with fibres oriented along motion direction of recirculation air. Lengthwise curvilinear grooves are provided on inner surface of suction branch pipe from inlet opening until outlet opening. Said grooves are connected with annular groove in front of outlet opening of suction branch pipe. Lower portion of annular groove is connected with contamination trap. EFFECT: enhanced effectiveness providing normalized parameters of air curtain due to lowered aerodynamic resistance against motion of recirculation air, removal of contamination out of air by means of solid and drop-like particles in suction branch pipe of compressor. 2 dwg