Questions about flame arrestors.
Thread Content
Flame arrestors are divided into those that prevent deflagration and those that prevent detonation. What are the structural differences between these two types of flame arrestors? How much is the difference in cost?
Personally, I think it has something to do with the type of filler used; you can ask the manufacturer for the price
Explosion-proof flame arresters can prevent subsonically propagating explosive flames from passing through; blast-proof flame arresters can prevent explosive flames that propagate supersonically and are characterized by shock waves from passing through. To prevent flames that propagate at subsonic speeds, flame arresters designed to suppress deflagration should be used, and they should be installed near the source of fire. To prevent flames that propagate at sonic or supersonic speeds, flame arresters designed to suppress detonation should be used, and they should be installed far away from the source of fire. Their flame-retardant principles are the same, their structures are not very different, and the price differences are also minimal. It’s mainly due to different installation locations.
I’m not sure if seniors are involved in process design – how is the propagation speed of explosion flames determined? Or is there any basis for it?
The flame arrester determines the test safety clearance based on the components of the test gas; standard 3413-2019 refers to NFPA497, which provides formulas for calculating the safety clearance for mixtures. The installation location also needs to take into account the pipeline conditions to avoid being in a non-steady state. It is also necessary to consider whether crystallization or freezing will occur; flame arrestors are an important safety measure that requires proper attention.
The price difference between deflagration and detonation is quite large, isn’t it? ! !
For the same manufacturer, the blast suppression ratio for detonation is about half as expensive as that for deflagration
I have a question: For the explosion suppression type designed to prevent deflagration and the type designed to prevent detonation, one requires being near a fire source while the other requires being away from it. What exactly is this fire source? For example, does the pipeline that supplies fuel gas to the boiler refer to one that is close to or far from the burner? For example, in the case of combustible gas venting systems, what is the name of the flame arrester installed on the venting pipeline that keeps it away from the source of fire? How is it considered close?
For potential sources of fire such as combustion equipment and fans, the installation location of the flame arrester is primarily determined by the L/D ratio, where L refers to the distance from the source of fire to the installation point of the flame arrester, and D refers to the diameter of the pipe, both in millimeters. If the L/D ratio is greater than 200, a steady-state detonation flame arrester should be used; if it is less than 50, a deflagration-arresting flame arrester is appropriate. When the gas in the pipe consists of hydrogen and the L/D ratio is less than 30, a deflagration-arresting flame arrester is needed. Steady-state detonation flame arresters are not restricted by the installation location.
The main differences lie in the number of layers of the flame retardant core and its thickness; the specific price should be asked from the manufacturer