Fire dampers in the design of the fair use of buildings in the event of a fire, often cause serious casualties and economic losses, especially air-conditioned buildings and high-rise buildings, fire prevention and smoke prevention is particularly important. In the design, should be familiar with the relevant normative requirements, set up a fire damper on the ventilating air conditioning system, and set up a smoke venting fire damper on the exhaust pipe to prevent the transmission of toxic high temperature flue gas during the fire, causing the fire spread and the toxic loss to increase.
1.There are several requirements for the setting and selection of fire dampers in ventilated air conditioning systems:
The duct passes through the fire compartment;
Crossing the air-permeable, air-conditioned machine room and important or fire-resistant room partition walls and floor slabs;
Fire dampers shall be provided on the horizontal pipe sections at the intersection of vertical ducts and horizontal ducts at each level. However, when each blasting and air-conditioning system of each building is independently installed, the fire pipe may not be provided at the intersection of the horizontal duct and the vertical main pipe in the fire compartment;
One on each side of the duct passing through the deformation joint. The fire damper in the above part is normally open, and when the temperature reaches 70 °C in the fire, it is automatically closed. Fire dampers should be placed close to the fire separation, and separate supports and hangers should be provided. When the fire damper is concealed, the inspection port should be installed at the installation site.
2.Vertical exhaust ducts for kitchens, bathrooms, toilets, etc., when no measures to prevent back flow are taken, fire dampers must be placed on the branch pipes. In the public building kitchen, in order to prevent the fire damper from malfunctioning due to the high temperature of the soot, a 150 °C blown fire damper should be installed at the intersection of the exhaust pipe and the vertical air duct.
3.The setting of the fire damper in the air conditioning centralized fresh air system design usually includes a layered horizontal fresh air system and a vertical fresh air system.
Hierarchical setting Horizontal fresh air system The fresh air system is set separately by floor. There are two ways to suck in the fresh air. One is that the fresh air is taken from the outside by opening a hole from the outer wall; the other is to set up a total fresh air vertical air duct, and the new wind turbines of each layer take the wind from the vertical air duct.The former method of taking fresh air does not require a fire damper at the entrance of the new wind turbine group, and the latter concentrates on fresh air. For high-rise buildings, the total fresh air vertical wind tunnel must cross the fire compartment.A 70°C blown fire damper shall be provided on the suction inlet duct of each new air blower unit.
Vertical fresh air system The vertical fresh air system is that the outdoor air is sent to the air-conditioned room through the vertical air duct after being processed by the new air blower group, and the general fresh air blower unit is set on the roof. It is more suitable for the case where the height of the building is low and it is difficult to lay a new duct horizontally. For high-rise buildings, the vertical air duct must cross the fire compartment, and the air supply port requires a 70 °C blown fire damper.