Date：2022-02-12
(1) The concept of fire damper and smoke exhaust fire damper fire damper refers to the valve installed on the air supply and return pipelines of ventilation and air conditioning system, which is usually open. In case of fire, when the gas temperature in the pipeline reaches 70 ℃, it will be actively closed, which can meet the requirements of fire resistance stability and fire resistance integrity within a certain time, and have the effect of smoke isolation and fire resistance.
Smoke exhaust fire damper is installed on the pipe of smoke exhaust system, which is usually open. In case of fire, when the gas temperature in the pipe reaches 280 ℃, it will be closed actively, and can meet the requirements of fire resistance stability and fire resistance integrity at a certain time. A valve with smoke and fire prevention effect.
(2) The effect of fire damper is a complex air supply and smoke exhaust system, and the pipeline is confusing. In the air supply system, the air sent by the air blower must be distributed to each branch pipe through the main pipe; In the exhaust or smoke exhaust system, the air or smoke is collected into the main pipe by each branch pipe and then discharged into the exhaust fan. Then, if there is no obstruction in the air supply system or smoke exhaust system, the air supply and smoke exhaust volume cannot be controlled. There are many air supply and smoke exhaust situations in the parts that do not need air supply or smoke exhaust, but there is no air supply, smoke exhaust or only a few air supply and smoke exhaust in the parts that need air supply or smoke exhaust. In order to cut off the pipelines that do not need air supply and smoke exhaust, valve equipment is required.
In addition, although the air volume of each part of the air supply and smoke exhaust system is calculated through the pipeline, the corresponding pipeline planning is carried out. However, on the one hand, there is a certain deviation between the theoretical accounting and the actual situation. On the other hand, the operating conditions of the system are constantly changing. Therefore, it is necessary to adjust the air volume of each part of the system accordingly, which requires valve equipment.
In addition, some ventilation devices, such as centrifugal fans, are started without load. Because the starting current of the motor is small, it is beneficial to safety. This requires cutting off the system pipeline before starting. When there is a switch at the inlet and outlet of the fan, it is generally necessary to close the inlet or outlet. If there is no switch at the inlet and outlet, it is necessary to operate it through valve equipment.
(3) The setting of fire damper and smoke exhaust fire damper shall be set on the pipeline of ventilation and air conditioning system, and smoke exhaust fire damper shall be set on the pipeline of smoke exhaust system, so as to prevent the transmission of high-temperature toxic smoke in case of fire, resulting in the extension and expansion of fire and the aggravation of toxicity.
1. In one of the following cases, the air duct of ventilation and air conditioning system shall be equipped with fire damper
(1) Where the pipeline crosses the partition wall of the fire compartment;
(2) The pipeline passes through the ventilation and air conditioning machine room and the partition wall and floor of important or high fire risk rooms;
(3) Horizontal pipe section at the junction of straight air duct and horizontal air duct on each floor;
(4) The pipeline crosses both sides of the deformation joint.
When the temperature of the gas in the pipeline reaches 70 ℃ in the fire, the fire damper at the above parts will be closed actively.
2. Separation of smoke exhaust system:
(1) A smoke exhaust fire damper that can be automatically closed when the flue gas temperature exceeds 280 ° C shall be set at the population of the smoke exhaust machine room. The smoke exhaust fan shall be able to work continuously for 30min at 280 ℃;
(2) A smoke exhaust fire damper which can be closed automatically when the flue gas temperature exceeds 280 ℃ is set on the smoke exhaust branch pipe.
(4) As an important part of building fire prevention and smoke control system, the quality of fire damper and smoke exhaust fire damper is directly related to the success or failure of the above system, the safety of building fire prevention and the safety of personnel dispersion.
