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    ZEF Elevated Flare Specifications Johnzink

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    candratrikusuma
    This document describes the specifications for a candlestick flare system to combust landfill gases from a landfill site. The key details include: - The flare system must be capable of continuously operating within the specified landfill gas flow rate and composition ranges, and meet the maximum heat release and temperature requirements. - The mechanical and structural design requirements include withstanding wind speeds up to 110 mph and being in a seismic zone 4. - The flare must meet various performance criteria such as stable combustion within the gas composition range, a 10:1 turndown ratio, emissions limits, and over 98% destruction efficiency of non-methane organic compounds. - The flare equipment includes a self-supporting base

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    © All Rights Reserved
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    ZEF Elevated Flare Specifications Johnzink

    Uploaded by

    candratrikusuma
    175 views8 pages
    This document describes the specifications for a candlestick flare system to combust landfill gases from a landfill site. The key details include: - The flare system must be capable of continuously operating within the specified landfill gas flow rate and composition ranges, and meet the maximum heat release and temperature requirements. - The mechanical and structural design requirements include withstanding wind speeds up to 110 mph and being in a seismic zone 4. - The flare must meet various performance criteria such as stable combustion within the gas composition range, a 10:1 turndown ratio, emissions limits, and over 98% destruction efficiency of non-methane organic compounds. - The flare equipment includes a self-supporting base

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    ZEF Elevated Flare Specifications Johnzink

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    This document describes the specifications for a candlestick flare system to combust landfill gases from a landfill site. The key details include: - The flare system must be capable of continuously operating within the specified landfill gas flow rate and composition ranges, and meet the maximum heat release and temperature requirements. - The mechanical and structural design requirements include withstanding wind speeds up to 110 mph and being in a seismic zone 4. - The flare must meet various performance criteria such as stable combustion within the gas composition range, a 10:1 turndown ratio, emissions limits, and over 98% destruction efficiency of non-methane organic compounds. - The flare equipment includes a self-supporting base

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    175 views8 pages

    ZEF Elevated Flare Specifications Johnzink

    Uploaded by

    candratrikusuma
    This document describes the specifications for a candlestick flare system to combust landfill gases from a landfill site. The key details include: - The flare system must be capable of continuously operating within the specified landfill gas flow rate and composition ranges, and meet the maximum heat release and temperature requirements. - The mechanical and structural design requirements include withstanding wind speeds up to 110 mph and being in a seismic zone 4. - The flare must meet various performance criteria such as stable combustion within the gas composition range, a 10:1 turndown ratio, emissions limits, and over 98% destruction efficiency of non-methane organic compounds. - The flare equipment includes a self-supporting base

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 8

    LANDFILL GAS ELEVATED (CANDLESTICK) FLARE SYSTEM

    Part 1. General
    1.01

    Description
    A. This section describes a candlestick flare system for the combustion of landfill
    gases. The flare system must be of industrial quality and be designed
    specifically for use in landfill gas service. The flare manufacturer shall have a
    minimum 10 years experience in the design and manufacture of this type of
    equipment and have a minimum of 25 candlestick flares in successful
    operation in the United States.
    B. The flare system to be supplied must be complete and operable as specified
    herein:

    1.02

    Design Criteria
    A. The landfill gas utility flare shall be designed to operate continuously at the
    following operation conditions:
    Landfill gas flow rate:

    __________ SCFM

    Composition:

    30% - 50% CH4


    Remainder CO2, air, and inert

    Lower Heating Value (LHV):

    ___________ BTU/SCF

    Temperature:
    LFG moisture content :
    Heat release:

    100F
    Saturated
    __________MMBtu/Hr

    (maximum)

    gases
    (maximum)

    B. Mechanical
    Design Wind Speed:
    Seismic Zone:
    Site Elevation:

    110 mph
    4
    __________ ft above sea

    Electrical Area:

    Non-hazardous (unclassified)

    level

    C. Unit Design
    Smokeless Capacity
    Pressure Drop
    Turndown

    100%
    <5 w.c. from inlet through
    outlet of the flare
    >10:1

    1.03

    Performance Requirements
    A. The candlestick flare system must be capable of achieving the following
    performance requirements:
    1. The flare must be capable of sustaining stable combustion with 30% 50% CH4 at the maximum required flow rate.
    2. The flare must be capable of a minimum 10:1 turndown.
    3. The flare exit velocity must be designed strictly in accordance with
    EPA 40 CFR Ch. 1 section 60.18, but shall not exceed 100 feet per
    second at any time.
    4. The radiation on any point at grade shall not exceed 500 Btu/Hr-ft2
    when the flare is firing at the maximum design heat release and with a
    20 mph wind. This radiation is to be determined via the 3-point
    method utilizing the radiant heat fractions at each point.
    5. Flame shape shall be determined and be based on the momentum flux
    differences between the landfill gas exiting the flare tip and the cross
    wind. The landfill gas should take into account the hydrocarbon
    concentration.
    6. Flame length shall be determined and be based on the maximum
    design heat release with allowances for the molecular weight.
    7. The pressure loss through the flare must be less than 5 w.c. from the
    inlet flange through the outlet of the flare.
    8. Emissions from the flare shall not exceed the following:
    Nitrogen Oxide (NOx) - 0.068 lbs per MMBtu Fired
    Carbon Monoxide (CO) - 0.37 lbs per MMBtu Fired
    9. The flare shall be capable of achieving a minimum destruction
    efficiency of >98% of total non-methane organic compounds
    (NMOCs).

    Part 2 - Products
    2.01

    General
    A. All equipment shall be designed and shall perform as a minimum in
    accordance with these specifications.
    B. These specifications are intended to be specific in nature such that the flare
    operator will not be in danger from radiant heat emitted from the flame, and to

    determine the location of the flare from nearby structures, power lines, trees,
    etc., based on the flame shape and flame length.
    2.02

    Equipment
    A. The landfill gas open (candlestick) flare system shall have the following items
    as a minimum:
    1.
    2.
    3.
    4.
    5.
    6.

    Self supporting base ring.


    Carbon steel stack
    Spark ignited pilot assembly
    Flare tip
    Ignition and control system
    Ancillary Equipment

    B. The equipment provided shall be designed specifically for use in landfill gas
    service. All components directly supporting combustion, such as the flare tip
    and pilot, must be manufactured by the flare supplier. Only ancillary
    equipment, such as gas blowers, flame arrestors, and instrumentation shall be
    manufactured by others.
    C. The control system shall be completely assembled and tested prior to
    shipment by the flare supplier at the supplier's own fabrication facility.
    2.03

    Equipment Description

    A. Self supporting base ring


    1. Minimum A-36 plate
    2. Minimum diameter bolt holes
    B. Carbon steel stack
    1. The flare stack shall be fabricated from A106-B standard weight
    carbon steel pipe up through 10 and A53-B carbon steel pipe from
    12 to 16.
    2. The inlet shall be a 90 entrance into the stack.
    3. The inlet shall project a minimum of 10 from the stack and terminate
    with a 150# ANSI FFSO flange.
    4. The inlet nozzle shall contain one (1) 1/2 FNPT connection on the top
    of the nozzle for a temperature switch to be mounted.
    5. A carbon steel inclined floor plate at least 4 below the lowest part of
    the inlet connection shall be seal welded to the interior of the stack
    with one (1) 1 3000# FNPT connection located as a low point drain
    connection above the inclined plate, on the down slope side.
    C. Spark ignited pilot assembly

    1. The pilot shall be spark ignited.


    2. The spark plug shall be located no closer than 5-0 from the end of
    the flare tip and shall be located in a position that is not considered a
    low point, that can collect water.
    3. The pilot shall consist of an ignition rod internal to the pilot assembly
    and shall be weather proof such that rain or condensation will not
    cause the ignition rod to arc out in a location other than the pilot tip.
    4. The arc (spark) that ignites the flare pilot shall be located at the pilot
    tip, such that the base of the pilot flame is directly adjacent to the arc
    (spark).
    5. The pilot shall consist of a cast iron self-inspirating capable of
    achieving the air/gas mixture required for proper pilot flame stability.
    This eductor shall have a windshield around the inlet air opening such
    that a cross-wind will not affect the operation of the pilot.
    6. The gas inlet connection to the pilot eductor shall be FNPT.
    7. The pilot tip shall be made from stainless steel and shall be positioned
    such that the main flare tip is ignited easily.
    D. Flare Tip
    1. The flare tip shall be a minimum length of 5-0.
    2. The flare tip shall be 304 stainless steel schedule 10S pipe of the same
    diameter as that of the carbon steel stack.
    3. The flare tip shall be continuously welded to the carbon steel flare
    stack with a 309 SS weld.
    4. The flare tip shall incorporate integral flame retention for increased
    flame stability.
    5. The flare tip wind shield shall be fabricated from 309/310 stainless
    steel.
    6. The wind shield shall be designed to educt the proper amount of air
    into the flame zone for stable combustion throughout the flow range.
    7. The flare tip shall have one (1) type K thermocouple assembly with
    310 stainless steel sheathing mounted to the stack for sizes 4 through
    8 and two (2) type K thermocouple assemblies with 310 stainless
    steel sheathing for sizes 10 through 16. Each thermocouple shall be
    located such that it detects the main flame throughout the entire design
    operating range.
    E. Control System
    Provide a complete and operational control system designed for
    480V/3ph/60hz incoming power and step-down as required to successfully
    operate the blower(s) and flare system. The control system shall be
    supplied with the following items completely pre-assembled on a
    structural steel rack:

    1. One (1) weatherproof single phase power transformer to convert


    electrical power service from 480 V to 120 V.
    2. One (1) weatherproof Flare Control Panel including the following
    instrumentation for safe, overall system operation and control:

    Allen Bradley Programmable Logic Controller or equal


    Honeywell DR 4500 Truline digital circular chart recorder for
    recording flow.
    Automation Direct 6 touch screen display or equal.

    The following switch and lights are required on the front of the control
    panel, as a minimum:
    Panel Power (On/Off) switch
    Power ON light (white)
    Flare operating light (green)
    Flare shutdown light (red)
    The following flare system status is required on the touch screen display,
    as a minimum:

    Flare start up status


    Thermocouple status (normal or cooling)
    Pilot gas ON/OFF status
    Igniter ON/OFF status
    Pilot proved status
    Auto valve status
    Blower status
    Flare thermocouple temperatures
    Flame arrester thermocouple temperature

    The following switches/settings are required on the touch screen display,


    as a minimum.

    System control (Local Off Remote)


    Blower control (Hand Off Auto)
    Main thermocouple setpoint
    Pilot thermocouple setpoints
    Reset switch
    Alarm acknowledgement switch

    The following alarms are required on the touch screen display, as a


    minimum.

    Manual stop
    Pilot flame failure

    Flame arrester high temperature


    Auto valve failure
    Blower failure
    Main flame failure

    3. One (1) pilot gas control system including pressure regulator, failclosed shutdown valve, manual block valve, and pressure indicator.
    4. Weatherproof combination motor starter for each gas blower.
    The following components shall be installed on or mounted to the flare
    stack.
    1. One (1) weatherproof Ignition Panel with 6000 V transformer mounted
    to the stack for intermittent pilot ignition.
    2. Main flame thermocouples.
    3. One (1) pilot assembly with integral thermocouple.
    The control station and instrumentation shall be assembled and wired
    completely in a facility approved by Underwriters Laboratories and shall
    be functionally tested prior to shipment simulating actual operation.
    F. Ancillary Equipment
    1. A flame arrester with aluminum body and removable, internal
    aluminum element shall be installed at the flare inlet flange.
    2. An automatic block valve assembly consisting of a high performance
    butterfly valve with 316 stainless steel disc and Teflon seal, and a failclosed pneumatic actuator shall be supplied.
    2. Gas blowers with totally enclosed, fan cooled motors (TEFC) shall
    supply the enclosed flare with landfill gas.
    3. A moisture separator vessel with flanged inlet and outlet connections,
    stainless steel demister element capable of removing 99% of water
    droplets 10 micron and larger from landfill gas, differential pressure
    gauge, and level gauge shall be supplied.
    4. A suitable amount of thermocouple and ignition wire shall be supplied.
    Part 3 - System Operation
    3.01

    General
    A. The flare system shall safely destroy 98% of the organic compounds
    generated by solid waste.
    B. The system shall be controlled by a programmable logic controller (PLC)
    which receives and transmits signals with respect to operating conditions. If
    an unacceptable operating condition occurs, the system shall discontinue
    operation.

    C. System operation shall include an initial timed ignition sequence, and fail-safe
    controls.
    D. System shutdown shall result pilot flame failure, main flame failure, automatic
    block valve failure, and flame arrester high temperature.
    F. Individual thermocouples shall monitor both pilot flame and main flame.
    3.02

    System Control Selection


    System operation begins automatically by selecting either local or remote system
    control. Local control requires interaction at the control panel to start and stop
    operation. Remote control allows starting and stopping operation without
    interaction at the control panel.

    3.03

    Operating Permissives
    System operation is permitted only after confirming two safety conditions exist.
    The closed limit switch for the automatic block valve must be satisfied, proving a
    closed valve position. Additionally, the pilot and main thermocouples must not
    detect the presence of flame.

    3.04

    Ignition Sequence
    When the flare Start switch is selected, the pilot gas solenoid valve opens
    automatically, supplying gas to the pilot, the "Pilot Gas ON" status is indicated,
    and the ignition transformer energizes. The ignition transformer continues for ten
    seconds and then the pilot thermocouple verifies flame is present. The "Pilot
    Proved" status indicates and the pilot gas solenoid valve remains open.

    3.05

    Gas Supply
    Once pilot flame is detected, the automatic block valve opens, operation of the
    selected gas blower begins, supplying gas to the flare, and the Blower On" status
    is indicated. After the open limit switch for the automatic block valve is
    achieved, the pilot gas solenoid valve closes and the "Igniter OFF" status is
    indicated. While the main thermocouple verifies flame is present, system
    operation continues. If the open limit switch for the automatic block valve is not
    achieved within twenty seconds, the "Auto Valve failure alarm is indicated on
    the display, and system operation discontinues.

    Part 4 - System Failure


    4.01

    Automatic Block Valve Failure


    If the open or closed limit switch on the automatic block valve indicates improper
    valve position at any time during start up or operation, the Automatic Block Valve
    Failure alarm will be indicated on the display and the unit will shut down.

    4.02

    Pilot Flame Failure and Shutdown


    Pilot Flame Failure occurs, during the ignition sequence, when the pilot
    thermocouple is unable to detect the presence of pilot flame. When Pilot Flame
    Failure occurs, system operation is interrupted momentarily. Then the entire
    ignition sequence is repeated automatically. A shutdown occurs only after three
    consecutive failures, or unsuccessful attempts. Once Pilot Flame Shutdown
    occurs, the "Pilot Flame Failure" alarm is indicated and system operation
    discontinues.

    4.03

    Main Flame Failure and Shutdown


    Main Flame Failure occurs, once the ignition sequence is complete, when the
    main thermocouple is unable to detect the presence of main flame. When Main
    Flame Failure occurs, system operation is interrupted momentarily. Then the
    entire ignition sequence is repeated automatically. A Shutdown occurs only after
    three consecutive Failures, or unsuccessful attempts. Once Main Flame
    Shutdown occurs, the "Main Flame Failure" alarm is indicated and system
    operation discontinues.

    4.04

    Flame Arrester High Temperature


    Flame Arrester High Temperature occurs when the temperature switch on the face
    of the flame arrester detects the presence of a flame, indicating a flash back. This
    will immediately cause a shutdown and the Flame Arrester High Temp alarm
    will be indicated.

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