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Enclosed Gas Flares
HiTemp Technology
(HTT) has developed a system that mixes the
methane stream with sufficient combustion air to
maintain a consistent temperature that assures
maximum destruction of any methane present in the
exhaust gas.
 A
standard system includes: Waste gas burner, flame
arrestor, combustion air blower (VFD), waste gas
ID blower (VFD), water separation drum, electronic
ignition, system alarm with cell dialer for Alarm
text, dual data logger for temp and flow,
refractory stack, and weatherproof controls.
The HTT system utilizes modular
components that are interchangeable and allow easy
access for repairs and maintenance. The design
utilizes basic control and combustion systems.
With this type of approach, we can design, build,
and ship in half the time normally required by
standard site assembled units. In special
situations, we can have a system on site and in
operation within 3-4 months of order placement.
Because the systems are modular, replacement parts
and capacity increases are made without major
changes in the basic design.
Design
For special applications, we
have designed a custom burner system, with an
induced draft/combustion blower sized for the
waste gas volume. Also availabe will be a optional
dual input valve train including, solenoid shutoff
valves, UV detection, and gas butterfly valve with
modulating control motor, keeping the system in
compliance with FM/IRI requirements. Waste gas streams with
a CH4 content of more than 20% will not require
any auxiliary fuel for operation. A small LP gas
tank is used only for ignition pilot. Typically
the bottle will be used only during
startup.
At startup, the combustion air
blower VFD will be set as required for minimum
output and the waste gas blower VFD will be set at
maximum output.
This is adjusted to bring the flare up, and
will be controlled at the set point as required. Once the
unit approaches set point, the air will
automatically adjust with the VFD until the
temperature set point is maintained.
LOW BTU WASTE GAS STREAMS
WILL REQUIRE AUXILIARY FUEL
The system is designed to control the secondary air
and fuel separately.
Adding only as much air as the process
requires will lower overall operating costs and keep
the chamber at temperature in standby condition. The system
will startup with minimal secondary air as the burners bring the
unit up to operating temperature. Once
temperature is reached the system will open the
secondary valve train to direct the flow to the
secondary burner injection point. The gases
will enter the chamber, mix with the secondary air
and will pass through the burner flame.
 Since the
waste gases contain a high fuel value, the
temperature will rise in the chamber, causing the
burner controls to decrease burner output. If the
heat content is high enough, the burners will drop
to low fire and the temperature will continue
to rise. The
secondary air dampers will be operated from the
second controller.
Once this set-point is reached, the damper
0pens and the secondary air is increased as it is
the secondary air volume that controls the
temperature. Typically, this air
set-point is 75o F above the burner
set-point. As
the heat value of the gas changes the secondary
air damper will adjust. The system includes
a 6” ceramic fiber refractory-lined horizontal or
vertical chamber.
The waste gas connection will be on the side
of the unit or at the blower inlet and the exhaust
stack connection will be on the top.
Installation requires setting
unit, utility connections and bolting on the
stack and customer provided supply duct.
GAS FIRED THERMAL
SYSTEM DESIGN DATA
Flow
Rate CH4 gases
XXXX
SCFM
Destruction
Eff.:
>99
%
CH4
Concentration:
20-60
%
CH4
Heat Input :
XXXX
MM BTU/hr
Operating
Temp:
>1500
F
Refractory
Lining:
6
In
Residence
Time:
>0.5
Seconds (@ 1500F)
Chamber Volume:
XXXX
Ft3
Max
Burner Input:
XXXX
MM Btu/Hr
Operating
fuel usage
XXXX
MM Btu/Hr
Specific
Requirements and Performance Specifications:
1. Complete flare/oxidizer system to treat
landfill gas methane in accordance with the NJDEP
air permit including the moisture knock-out pot,
blower package, motors, drives, flame arrestor,
valves, piping, burners, flare/oxidizer, stack,
safeties, monitoring sensors, control panel,
controls, power panel, conduit, wiring and other
features as needed.
2. Associated documents such as shop drawings (4
copies), equipment submittals, (4 copies),
maintenance and operating manuals, (4 copies),
foundation templates, spare parts (recommended
parts and quantities), start-up support services
and operator training.
3. Start-up support services include a start-up
test report to confirm that flare is operating
correctly and conforms with performance
requirements.
4. Provide an option for the installation of a
flanged exhaust gas nozzle to be installed on the
side of the enclosed stack (or other proposed
solution) for a future heat recovery system. The
use of direct heat recovery has been proposed to
recover heat for the adjoining warehouse building.
This may be accomplished by drawing exhaust gasses
through a gas-to-water heat exchanger
incorporating a variable speed forced draft fan. The nozzle should be sized to take
advantage of the maximum amount of exhaust gas
heat recovery but without reducing or eliminating
stack draft to reduce stack temperatures below
minimum requirements.While not required as part of the system,
accommodations for a direct heat recovery system
may be requested as an option.
5. Flare/Oxidizer Capacity of 500-1000 SCFM
expected typical operating range of landfill gas
shall be 30% to 50% methane by volume for use to
vent the vertical well landfill gas and provide
combustion through the flare with minimal
supplemental fuel.
6. Combustion Blower package capacity of up to
3,000 SCFM @ 10 inches of water column for
combustion air through the Flare/Oxidizer. Blower
shall be operated through a VFD with a control
signal provided by the Temperature Controller.
7. CH4 Blower package consists of one (1) blower
with the full capacity of the unit. A flow
regulation mechanism using variable frequency
motor drives is provided for each blower so flow
can be adjusted from 300-500 CFM. (or lower as
needed).
8. High "turn down" (ability to handle high
variation in landfill gas flow rates)
9. Smokeless design with no visible
emissions
10. VOC Removal Efficiency greater than, or equal
to ninety-nine percent (99%)
11. Minimum exhaust temperature greater than, or
equal to 1,500o F
12. Residence Time greater than, or equal to 0.5
seconds
13. Auto shutdown if combustion chamber
temperature of 1,500o F cannot be
maintained for 10 minutes
14. Provision to monitor/alarm the pilot flame
15. Provision to monitor/alarm the flame
16. Provision to monitor/record temperature in the
combustion chamber
17. Provision to monitor/record/alarm methane,
oxygen, carbon dioxide and gas flow rates
18. Automatic system to relight the flare
19. Auto shut-off of landfill gas supply and alarm
if auto relight fails to start the flare
20. High temperature switch that turns off waste
gas supply and alarm indication if a "flame-back"
is detected
21. Integration into a control panel of telemetry
associated with the blower
22. Multi-point monitoring and recording for
temperature and waste gas flow with readouts from
the control panel
23. All wiring, equipment, lighting and
ventilation in accordance with current version of
the National Electrical Code, "Special Occupancy,
Hazardous Location"
24. Alarm system actuating an automatic cell or
mobile phone dialer system. Text messages may be
sent to up to 10 cellular or mobile phones. System
may be designed to use text messaging with
password to start, stop or notify of system status
For additional information, please
visit our Downloads
page.
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