Transcript Slide 1

Innovative Wellhead Products
for Landfill Gas Management
QED Presenter
QED Environmental Systems Inc.
Ann Arbor, Michigan - San Leandro, California
Copyright © QED Environmental Systems, Inc. 2013; all rights reserved. The information contained within this document
may not be published, broadcast, rewritten or otherwise distributed without the prior written authorization from QED.
LFG Well Field Management Goals
• Maximize LFG energy content (flow rate and methane
concentration) where gas is utilized
• Avoid NSPS violations for PTO exceedance
• Comply with LFG emission regulations
• Avoid odor complaints from neighbors
• Reduce time and labor spent for well field management
• Reduce and simplify well field maintenance and repairs
Maximize gas collection efficiency while maintaining
regulatory compliance, all at the lowest possible cost
Traditional LFG Wellhead Designs
• PVC gate valve for flow
control is most commonly
used – low cost, widely
available
• Union orifice plate, Pitot
tube or venturi used for flow
measurement (calculated
from differential pressure)
• Flexible rubber couplings
used for connections to the
well riser and wellhead
Problems with Traditional Wellheads
• Gate valves were designed for controlling liquids, not for
regulating gas flow – small adjustments in valve
opening can result in large changes in applied vacuum
and resultant flow, often resulting in “over-pulling” on the
well and air leaks into the landfill and the gas system
• Field techs can’t determine valve position, so recording
changes in valve settings is reduced to counting “valve
turns” – highly subjective, not truly reproducible
• Gas flow measurement can be highly inaccurate - pitot
tubes, venturis and orifice plates all have accuracy
limitations or can be difficult to use, resulting in flow
measurement and reporting errors
Flow Control Using Gate Valves
Advantages
• Lower initial cost
• Widely available
Closed
Open
Disadvantages
• Non-rising stem - operator can’t observe valve opening position
• Plastic threads can strip easily, plastic handle breaks off with age
• Seals fail, dirt and grit get into threads and gate track, and extreme
cold and heat all make valve difficult or impossible to adjust or
cause the valve stem to break when excessive force is applied
• Fully open in 3-4 turns out of 10 - flow adjustment isn’t linear
and can be difficult to regulate, especially at low flow rates
Precision Fine Tune Control Valve™
• Patented flow-tuned valve design provides precise, linear
control of flow from fully closed to maximum flow
• Rising stem design and highly visible metered scale
allows observation of valve position setting, making it
easy to quickly return to the exact setting if the valve
must be closed
• Rugged stainless steel valve stem and
handle make it more durable in harsh
outdoor environments.
Precision Fine Tune Control Valve™
QED Precision Valve vs. PVC Gate Valve
• PVC gate valve offers very little flow control, especially at lower flow
rates, with maximum flow achieved at just four turns
• QED Precision Valve has nearly linear flow control across entire range
of valve opening, with unparalleled control at flows under 20 CFM
Case Study
South Texas Landfill – Well 54
The QED Precision Fine-Tune Valve eliminated wide swings in methane
concentration and air leaks into the well, improving the overall gas quality
while avoiding NSPS violations
The Value of Better Flow Control –
Improved Gas Heat Content
Additional Annual Gas Value @ 1% Methane Increase
Gas Value
($/mmBtu)
$1.50
$2.00
$2.50
$3.00
$3.50
$4.00
1 CFM
5 CFM
10 CFM
25 CFM
50 CFM
$8
$11
$13
$16
$18
$21
$40
$55
$65
$80
$90
$105
$80
$110
$130
$160
$180
$210
$200
$275
$325
$400
$450
$525
$400
$550
$650
$800
$900
$1,050
100 CFM
$800
$1,100
$1,300
$1,600
$1,800
$2,100
As little as a 1% increase in methane concentration at a gas value of
$2.00/mmBtu in a 50 CFM well can pay for a QED Precision Wellhead and
Stabilizer Well Cap in just one year
 Try the latest QED LFG Calculator at www.qedenv.com/landfillgas2
Common LFG Flow Measurement Methods
Pitot Tubes are intended to fit a wide range
of flow rates, but can easily clog with
condensate, mineralization and corrosion,
and have poor accuracy at flows under 20
CFM (± 5-10% at best, ± 20% worst)
Venturis are also a “one size fits all” device,
but create significant pressure drop at high
flows (>12” WC @100 SCFM) and
insufficient pressure drop for reliable
measurement at flows under 25 SCFM
Orifice Plate sizes can be selected to
match changes in flow rates, but changing
plates can be time consuming, requires
shutting off gas flow and breaking pipe
connections, and gas techs can’t see the
plate size without opening the pipe union
Quick-Change™ Orifice Plate
• Utilizes proven orifice plate technology
for accurate and repeatable flow rates
• Plates can be swapped out by one
person in seconds to achieve desired
∆P with changes in gas flow rate
• No time wasted shutting down the
control valve, breaking pipe
connections or rebalancing the well
• Accessible plate housing allows for
easy confirmation of plate size and
placement reducing reporting errors
• Durable PVC construction with
stainless steel orifice plates
Quick-Change™ Orifice Plate
Quick-Change Orifice Plate can be changed in less than 60
seconds by one person without interrupting LFG flow, saving
as much as 1-2 labor hours over traditional union orifice plates
Problems with Traditional Well Caps
• Flexible coupling “stacks” and “donuts” tend to leak air into gas
system and leachate from foaming wells
• Couplings aren’t very strong, so wellheads lean and wobble
• Liquid level measurement requires cap removal, shuts down
gas flow, and exposes operator to LFG emissions
QED Stabilizer™ Well Caps
• First engineered LFG well cap that aligns and stabilizes the
wellhead, minimizing air leaks and gas release
• Unique support ring molded directly into the cap (patent
pending) takes the side load off Fernco® and flex hose
• Watertight threads help reduce
leachate leaks from the wellhead
• Minimizes air leaks into the gas
system, greatly reducing the cost
of gas treatment for gas-to-energy
and high-Btu LFG projects
QED Stabilizer™ Well Caps
• Easy liquid level measurement without
removing the well cap or shutting off gas
flow – faster, safer, cleaner, easier
• Ports to accommodate pump fittings for
dewatering applications and dedicated
bubbler line or Easy Level indicator
• Caps are molded in high-visibility
bright yellow, helping identify and protect
the entire well from damage
• Durable, heavy-walled polyethylene
construction makes it ideal for any climate
• Fits 6” and 8” wells with 2” or 3” LFG
wellheads
QED Precision™ LFG Wellhead Designs
All featuring the Precision Fine-Tune Control Valve
Handle Lateral
Handle Vertical
Vertical with Quick-Change
Orifice Plate System
Horizontal with Quick-Change
Orifice Plate System
Quick-Change™ Orifice Plate Wellhead
• Revolutionary Quick-Change
orifice plate system for
accurate flow measurement
at any flow rate
• Precision Fine-Tune Valve for
precise flow control over a
broad flow range
• Emphasis on increasing the
visibility of the wellhead
includes diamond reflector
tape and bright yellow
labeling and wing-nut handle
Quick-Change™ Orifice Plate Wellheads
• Available in 2” and 3” pipe sizes for flows up to 300 CFM
• Brass barbs or quick-connects for flow measurement and LFG sampling
• Orifice plate kits contain a range of plate sizes to match flow range of valve
Wellhead System Drawings
Free QED Wellhead Trial Offer
Try a QED
Precision Wellhead
for 60 days at no
charge
At the end of the
Trial Offer you may
purchase the unit
or return it to QED
Questions?
QED Presenter
QED Environmental Systems, Inc.
Ann Arbor, MI and San Leandro, CA
www.qedenv.com
E-mail: [email protected]
Toll-free: 800-624-2026
Direct: 734-995-2547
Local QED Sales Manager/Rep Info
Rep name/company
Telephone: 123-456-7890
E-mail:[email protected]