In high-rise buildings, there is a thick metal door on each floor, and it is marked with a reminder: normally closed fire doors are not allowed to be normally open. Its function is to effectively block the smoke and fire in the event of a fire, and to ensure that the escaped personnel in the evacuation stairs are not infringed by the smoke. This door must be closed, otherwise it will lose its effectiveness, and the "passage of life" will become the "passage of life". Recently, the fire rescue department has conducted experiments to demonstrate the smoke and fire prevention effects of normally closed fire doors.
Experiment 1: Firefighters use smoke cans to simulate fire-producing substances, place the smoke cans in the front room of the elevator on the 9th floor, open all the normally closed fire doors in the enclosed stairwells above the 9th floor, and open the smoke cans. About 34 seconds later, the smoke jumped to the 10th floor and quickly spread to the upper floor. Firefighters imitated the escape personnel to escape from the 12th floor. At this time, the smoke had spread to the evacuation stairwell, making it extremely difficult to escape.
Experiment 2: In the comparative experiment, firefighters reopened the smoke canister on the 9th floor and closed all the normally closed fire doors above the 9th floor. At this time, the front room of the elevator on the 9th floor was instantly filled with smoke, but because the normally closed fire door was closed, the smoke was effectively prevented from spreading. Only a small amount of smoke infiltrated in the evacuation stairwell on the 9th floor, so the trapped personnel can be safe. Evacuate through this "passage of life".
Through two comparative experiments, it can be clearly found that the normally closed fire door can effectively block smoke and fire when it is closed. In a real fire field, due to the higher smoke temperature, the flow and spread speed will be faster. Spreading through the safety exit to the evacuation stairwell will cause greater damage to the escaped personnel, and the enclosed stairwell will lose its evacuation function.
The fire rescue department reminds the general public that the normally closed fire door should be closed in time after passing through, and the opening and closing device of the normally closed fire door should not be artificially damaged. The property management unit should strengthen daily inspections and inspections, and timely repair and replace the normally closed fire door Damaged components, to ensure that the normally closed fire door is always in the closed state, and effectively play a role in preventing smoke and fire.
