METHOD AND DEVICE OF AUTOMATICALLY MAINTAINING THE PRESSURE DIFFERENCE IN SMOKE FREE SAFETY ZONE USING DIFFERENTIAL HEAD SWITCH

摘要

PURPOSE: A method and device of automatically maintaining the pressure difference in a smoke free safety zone using a differential head switch are provided, thereby 40 to 60 Pa of the pressure difference between the smoke free safety zone and indoors can be maintained continuously. Therefore, the rescue of refugees can be easily carried out. CONSTITUTION: The method of automatically maintaining the pressure difference in a smoke free safety zone comprises the steps of: blowing air into the smoke free safety zone and indoors by using a ventilator when the fire is occurred; maintaining the pressure difference between the smoke free safety zone and indoors to 40 to 60 Pa using differential head switch applying an electric conductivity of water; operating a relay by operating a manometer of the differential head switch when the air pressure of the smoke free safety zone is increased; and controlling the open and close of a damper by clock wise or anticlockwise rotation of a motor according to operation of the relay to control the inlet of air. The device of automatically maintaining the pressure difference in a smoke free safety zone is composed of a number of ventilators, a number of differential head switches, a number of relays connecting with an electric power source V1, a number of damper opening and closing motors connecting with an electric power source V2; and a number of dampers.