Τhe fire safety curtain is an essential mechanism imposed by the Fire Protection Regulation. The curtain is constructed and installed in such a way that, when closing, it interrupts the passage of hot gases, flames and some coming from the fire on stage, and protects the audience from radiation for quite a long time, as postulated by Regulations. The curtain must close automatically. The nominal load of the mechanism is determined by the stage mouth dimensions. Velocities range up to 0,35m/sec.
The mechanism’s operation is based on the principle of coil winding. An electric gearbox rotates a coil around which the fireproof materials wind up transferring motion to the bar playing the role of balance weight. The fireproof materials stretch and unwind (as a result of the balance-weight bar and the weight of the materials themselves) until they reach the floor. The reverse process takes place when the fireproof materials undergo the winding procedure.
The winding fire safety curtain comprises the following individual components:
1. Engine Block / 2. Gear box system / 3. Coil system / 4. Engine block deck / 5 Coil base / 6. Coil bearing bush / 7. Safeties limit switches / 8. Fireproof Curtain / 9. Automation panels, PLC Software, Inverters etc. / 10. Mechanism complimentary (screws, nuts, conical, spring washers, emergency stops, safety bolts, stretching system etc.).
The control panel with PLC software is installed at the stage mouth. The mechanism is automatically actuated by the fire detection system of the building. The Programmable Logic Controller (PLC) has two buttons for the ascent and descent of the Curtain, and one security button (mushroom) with a key switch. Velocity is regulated through the control program. When the highest or lowest position is reached, the movement towards that direction stops. When a safety limit switch gets actuated, the mechanism is totally immobilized. Then, brakes are automatically actuated to keep the mechanism to its proper position.
The curtain is made of the highest class fireproof fiberglass fabric. To prevent the passage of gases, metal barriers are used on both sides of the vertical motion. The second horizontal block seals the floor.