Explosion relief vents

Explosion suppression has the following advantages and disadvantages compared to explosion relief venting ... 

Process equipment does not need to be located in an area suitable for explosion relief venting. 

Suppression systems are generally more expensive to install and maintain than explosion relief venting. 

Explosion relief venting is the process of relieving the explosion products (pressure and flame) from the plant to a safe location. The principle of explosion relief venting is that a dust explosion in a vessel causes vent(s) of sufficient area to open rapidly and relieve hot gases and dust to a safe location. In other words, the vessel fails in a predictable way such that people and plant are protected from the effects of the dust explosion. 

Explosion relief venting has the advantage of being relatively inexpensive compared to other explosion protection options and is simple to install in many cases. 

Some of the limitations of explosion relief venting include ... 

Explosion Relief Venting Requirements. Three elements are required for the design and specification of explosion relief vent(s) for a vessel ... 

Sparking in the precipitator could cause explosions of partially burned fuel. ere there is a risk of significant levels of combustibles, a combustibles meter should be fitted and used to de-activate the precipitator when the level of combustibles exceeds a pre-set value. As an additional precaution, the precipitator housing should be fitted with an explosion-relief vent. 

A wide variety of explosion relief venting is available to the industry. Bursting disks, displacement panels, and hinged... 

Ideally, the best location for an explosion-relief vent wonld be as close as possible to the sonrce of ignition however, predicting the ignition source is nearly impossible. Realistically, the vent should be positioned where it is least affected by internal fittings, which could increase turbulence if the flame front has to pass through them. The vent may be on the side or the top of the equipment. 

In many situations, it is not possible to ensure reliably that an explosion can be prevented - hence the need for explosion protection such that the effects of an explosion are limited to an acceptable level. The three methods of protection are containment, explosion relief venting and suppression. These are usually used in conjunction with appropriate preventive measures. 

An explosion relief vent must be carefully sized to ensure that it will effectively relieve the potential explosion. Factors influencing the calculation include the material explosion pressure characteristics, the plant strength, vent position and the influence of ducting if required. Consideration must also be given to the plant configuration and the availability of an area into which the explosion can safely be discharged. 

There is much guidance available in the literature regarding explosion relief venting with the nomograph method being, perhaps, the most widely used technique for deriving vent areas. This and other available techniques are considered in detail by Lunn [16] and the NFPA [17]. 

Basic solvent characteristics 10 4.4.4 Explosion relief venting 78... 

Is explosion relief venting adequate Is the explosion relief properly directed ... 

A wide variety of explosion relief venting is available to the industry. Bursting disks, displacement panels, and hinged covers or doors with spring-loaded or magnetic catches and automatic trigger vents are all in use. Selection of the specific type should be based on... 

Ideally, the best location for an explosion-relief vent would be as close as possible to the source of ignition however, predicting the ignition source is... 

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