API Std 537 2003 pdf free download
API Std 537 2003 pdf free download.Flare Details for General Refinery and Petrochemical Service
3 Definition of Terms Terms used in this Standard as they relate to fares are defined in 3.1 through 3.68. 3.1 air seal: A device used to minimize or eliminate the intrusion of air back into the riser from the exit. 3.2 assist gas: Fucl gas that is added to relief gas prior to the flare burner or at the point of combustion in order to raise the heating value. 3.3 back blowing: The procedure by which the dry air seal drain line is blown back from the base of the drain into the buoyancy seal to ensure the line is clear. 3.4 blowoff: The loss of a stable fame where the flame is lifted above the burner. This occurs if the fuel velocity exceeds the flame velocity. 3.5 buoyancy seal: A dry vapor seal that minimizes the required purge gas needed to protect from air infilration. It functions by trapping a volume of light gas in an internal inverted compartment. This prevents air from displacing buoyant light gas in the flarc. 3.6 burnback: Internal burning within the tip. This might result from air backing down the flare burmer at purge or low flaring rates. 3.7 burn-pit flare: An open excavation normally equipped with a horizontal flare bumer that can handle liquid as well as vapor hydrocarbons. 3.8 burning velocity: The speed at which a flame front travels into an unburned combustible mixture. 3.9 coanda flare: A flare bumer that is designed to employ the aerodynamic effect where moving fuids follow a curved or inclined surface over which they flow. Flarcs of this type generally use steam or pressure to achieve smokeless performance. 3.10 combustion air: Air required to combust the flare gases. 3.11 combustion efficiency: The percentage of the combustible fluid totally oxidized in the burner. In the case of hydrocarbons, combustion efficiency is the weight percent of carbon in the original fuid that oxidizes completely to CO2. 3.12 condensable gas: A vapor that can condense at the temperature and pressure expected in a flare header during or after a flaring event. 3.13 derrick support: A support system for the elevated flare riser normally used for very tall flares or when plot space is limited. Various derrick supprted arrangements are avail- able: a fixed system has its riser permanently supported to the derrick; a dcmountable derrick has multiplc riser scctions that are designed to be lowered and removed to permit lowering of the flare burmer to grade; a demountable derrick with one fixed riser provides for a single piece design to be lowered to grade as a single component. 3.14 design flare capacity: The maximum design flow to the flare normally expressed in kilograms per hour (pounds per hour) of a specific composition, temperature, and pres- sure. 3.15 destruction efficiency: The weight percent of the fluid vapor that can be oxidized that is at least partially oxi- dized. In the case of a hydrocarbon, destruction efficiency is the weight percent of carbon in the fluid vapor that oxidizes to CO or CO2. 3.16 detached stable flame: A flame which is not in contact with the fare burmer itself but burms with a stable flamefront in the vicinity of the flare bumer. 3.17 direct ignition: Ignition of a pilot by a spark at the pilot rather than by a flame front generator.
4.2.2 Horizontal The flared liquids and gases are piped to a horizontal flare burner that discharges into a pit or excavation (see Figure 4). . 4.2.3 Enclosed Flame Flares Enclosed fares are constructed to conceal the fame from direct view. They can reduce noise and minimize radiation. Unlike an incinerator, a wide turmdown is inherent with these systems. The normal flow rate allows the connected facility to start up, shutdown, and operate on a day to day basis without exposed flame flaring. Multiple stages within the enclosed flares are sometimes used. Figure 5 illustrates a side fired enclosed flare.
