Elevated Flares
Self supported, guyed or derrick


FQI model
This model uses an integral windshield, in 310 SS, that avoids flame impingement on tip as well as protects pilots from high winds and rain. It is a dished head welded to a conical Skirt, removable, that also allow to install temporary lifting lugs to easier tip removal.

Multipoint
STREL models were developed to minimize smoke and radiation dividing the stream in several small flames using perforated sub headers or radial arms. When required, they are supplied with heat shields, stages or inclined tips that swirls the exit stream promoting a better combustion.
Smokeless
They may use steam, air or gaseous fuels to decrease smoke. Injection is done by a central tip or a ring, fitted with multiple tips that are oriented to produce a swirl that enhances combustion efficiency. The ring is protected from flame impingement by the integral windshield.
The use of air for smokeless operation is the preferred option for continuous burning or when steam is not available. Air benefits from low operational cost and low noise being the larger initial cost the main disadvantage.
Gas assisted
Stream properties that favor the use of this type of flare are:
- LHV lower than 2.000 kcal/Nm3,
- Heavy hydrocarbons that produce smoke,
- Chemicals, such as NH3, of difficult combustion,
Assist gas is used in the same way as steam in smokeless flares.
Low heating value tips
These flares use special designed tips that allow continuous burning of gases such blast furnace gas. The windshields may be cylindrical, made from perforated plate or with vertical strips, or a divergent / convergent arrangement, thermal insulated, to sustain combustion. In some application a rain protection is installed to further improve combustion in adverse meteorological conditions.
Sonic
The high-pressure sonic type flares produce a smokeless operation as well as handle streams containing 1% of liquids droplets. The high noise generated is a limitation to be taken into account.
Accessories
- Flame front ignition system, manual or automatic,
- High energy ignitors,
- Flow meters,
- Self supporting, guyed or derrick,
- Water seal or KO drum,
- Molecular seal or dynamic seal,
- Pilots with high efficiency venturies, 304 or 310 SS, machined or cast with windshield and rain shield and three controls.
- Ladders and stairs, painted or galvanized,
- Pilots monitoring by double thermocouple,
- Purge gas and steam skids.
Resources
- Flaresim (http://www.softbits.co.uk/fs_overview.php),
- SelfStack and GuyStack