ENCLOSED "Zero Flares"
Home Products FLARES Rentals Services Tech Section Users
9 Pages -- Details / Applications / Testing -- see BELOW
With no smoke, no odor, no visible flame, no objectionable noise, no
expensive steam and no air blowers,
state-of-art NPAC ™ (NAO Populated Area Combustors™), also called enclosed "zero flares", low profile
"ground flares" or thermal oxidizer flares, destroy hydrocarbons, volatile organic compounds (VOCs),
odors and other objectionable waste streams with a thermal oxidation efficiency better than 99.99%.
In use throughout the world in refineries, chemical/petrochemical facilities, gas pipelines, tank farms,
and dockside and inland loading terminals located in populated urban areas, these versatile pollution
control system are also employed for ship-mounted thermal incineration of hydrocarbon and other
combustible vapors on the high seas.
Enclosed "Zero Flares", also called ground flares, populated area
combustors or "thermal oxidizer flares", offer many advantages in
comparison to open, elevated flares. The principal advantages of
enclosed flares, properly designed and manufactured to ISO-9001
quality standards, can be summarized as no SSNO (pronounced as
"no snow"), as provided by Mobil Oil (now -- ExxonMobil) engineer.
— No smoke
Other advantages include: Very low noise; very low and controlled
emissions; no thermal plume; very simple and fully accessible controls; convenient service of all components
at grade level (for example, pilots can be removed without shutting down a unit); no thermal radiation
(heat shield) problems; and ultra-safe, ultra-dependable destruction of liquid and gaseous wastes.
As with all flares, safety and reliability must be the two most important
considerations. Hence, the double S
in SSNO also stands for safety. Safe, reliable operation of all flare systems depends primarily upon the
design/performance of the flare burners and the reliability of fully automatic, fail-safe interlocked sensors,
pilots and controls. The actual flare burners are the heart of the enclosed flare system. Instrumentation and
controls are the nervous system and the brains.
The NAO state-of-art enclosed flares
offer two very
significant advantages: (1) They provide
smokeless incineration of the heaviest, hardest-to-burn waste gases/offgases and watery,
low energy wastes without any costly steam, troublesome air blowers, or exposed burners
and headers; and (2) they can be easily monitored to insure their overall efficiency & performance.
A true thermal oxidizer flare provides a waste gas/offgas and waste liquid
removal efficiency (DRE) better than 99.9 percent — for unsurpassed control of sulfur
oxides (SOX), nitrogen oxides (NOX) and other volatile, carcinogenic emissions
Free-Floating, High Performance, Low Emission Burners
Unsurpassed safety and world-proven dependability are maximized in NAO
low-profile enclosed flares by
combining innovative, practical designs with no short-cuts in manufacturing. Fully automatic multi-stage
operation of the free floating multi-tip, multi-jet burners, for example, assures dependable control of
waste gases, offgases and other objectionable waste streams from oil/gas energy fields, refineries,
chemical/petrochemical plants, and other manufacturing/processing operations.
Because the patented NAO flare burners assure uniform mixing of ambient air
with waste streams
— without any costly steam — they eliminate the very significant operating costs (often in the
neighborhood of U.S. $1-million per year) and the maintenance/reliability problems associated
with exposed burners used by other companies. Exposed burners have poor design/performance ratings.
With more than 500,000 worldwide burner
installations, including units manufactured in the 1920s & ’30s
that are still in service, NAO is fully committed to supporting all existing worldwide installations and
to maintaining its position as the leading innovator for ultra-reliable combustion, pollution-, safety &
Unsurpassed safety for NAO enclosed "zero flares" is further
assured by automatic interlocks, liquid seals,
ultraviolet (UV) scanners, fail-safe startups and shutdowns, warning lights, staged burner heads with
built-in flame/detonation arrestors, and remote-spark pilots with UV scanners. Optional safety devices
include gas detectors, video monitors, alarm horns, and automatic fire-suppression systems.
Before a unit can be started, the automatic controls verify all built-in
safeguards. Each burner pilot,
with its individual UV scanner, must prove ignition before the staged burner heads can be turned on.
Automatic fail-safe shutdowns will be initiated if there is a flame failure, loss of fluid in the liquid seal,
or if the system cannot be brought back into adjustment.
This combination of fully interlocked, automatic safety features for
ultra-reliable burner operation has
been incorporated into NAO enclosed flares for populated areas and shipboard installations.
Modular panel, clam-shell and other structural configurations are available.
Asia Leads the World
Although the design and development of low-profile enclosed flares were
pioneered in the United States,
it is interesting to note: Most installations of NAO’s environmentally friendly, populated area flares are in
Southeast Asia, Australia, Japan, China and Korea.
Unfortunately, there have been unsuccessful installations of poorly designed
and/or poorly manufactured
"thermal oxidizer flares" — units with exposed burners, and thermal expansion, steam pulsation, steam
noise, steam control and other serious problems. Those bad installations have never operated properly.
Several very expensive ground flares, with obsolete and unsafe designs manufactured by competitors,
have been abandoned.
In most cases, the principal problem was side-mounted, exposed burners. These
complex staging systems and large quantities of very expensive steam with noise and pulsation
problems. Since the exposed burners and headers are also subject to thermal expansion, they
have a reputation for very high maintenance and very poor performance.
One flare manufacturer has attempted to solve its exposed burner problem by
waste gas through a matrix of small holes adjacent to shaped fins. Although this exposed
matrix fin burner configuration improves gas/air mixing and combustion efficiency, it creates
very severe thermal expansion, reliability & maintenance problems. It also reduces burner life.
Performance Is the True Test
The true measure of reliability is performance in-the-field.
NAO flare systems, elevated and enclosed, have earned a worldwide reputation
safety and trouble-free operation, day after day, year after year, regardless of variations in
waste stream pressures and flows. These systems are built right, to ISO-9001 quality standards,
utilizing innovative concepts and practical designs which are based on experience, empirical
knowledge and a corporate commitment to treat all customers as valuable long-term friends.
The commitment to treat all customers as friends and as partners in joint efforts to solve unique
safety and pollution-control problems is taken seriously.
NAO maintains the world’s largest fleet of portable pollution solutions to
help customers with
plant shutdowns, scheduled and unscheduled, and for emergency response to leaks, spills
and soil/sludge remediation projects. These portable pollution solutions include self-erecting,
trailer-mounted open flares and enclosed flare/thermal oxidizer systems of all sizes.
Using a portable thermal oxidizer, the company developed special
tunnel-burner flare tips to
replace the very expensive and inefficient incinerators, traditionally used to burn low energy
gases from wood wastes (explosive saw dust), carbon black (amorphous carbon) byproducts,
and other dangerous wastes with calorific values as low as 2000-2400 KJ/Nm3 (50-60 Btu/scf).
Because large volumes of assist gases are required by a multi-million-dollar
operating cost typically averages U.S. $125,000 per month. Despite a high capital investment
and very high operating costs, waste-gas destruction efficiencies do not satisfy worldwide
environmental regulations. Safety also leaves a lot to be desired.
NAO’s unique tunnel-burner tips, developed for elevated (open flares) and
flares, eliminate the need for expensive assist gas; provide a destruction removal efficiency (DRE)
better than 99.9 percent; and significantly reduce harmful, dangerous emissions that contribute
to acid rain and global greenhouse warming.
More information on ENCLOSED FLARES -- Click on each picture sheet.
For more information, please call, fax or Email for typical drawings, technical reports, price and brochures.