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Other Blending
Applications |
Piston Operated Mixers (POM)
for other Applications
POM-30, POM-40, POM-60, POM-80, POM-100 |
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In addition to the
"traditional" applications of LP/Air mixing in backup, standby,
and PeakShaving
systems, the AES POM blenders can also be used for a variety of
other applications where reliable performance, ease of use, high
turn-down ratios, adjustable mixing ratios, and low maintenance are
desired. |
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The following
paragraphs describe just a few of the many installations where POM
blenders have been used successfully. The main feature that these
applications have in common is that two dissimilar gasses needed to
be blended at an adjustable ratio.
The AES POM blenders can mix any two or more gasses safely and
reliably. |
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Natural Gas Stabilization |
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Situation:
A manufacturing line for tempered glass (TV picture tubes) is
supplied by NatGas with fluctuating heating value (Calorific Value, CV).
The fluctuations are significant enough to upset the production results.
Solution:
Installation of a POM blender with Automatic Gas Properties Control
(AccuBlend™).
Operation:
The POM blender is supplied with NatGas and with Air. The POM is
pre-set to a blending ratio that results in slightly "diluted"
NatGas/Air mixture with a CV that is acceptable to the process. A
Calorimeter at the outlet of the POM measures the CV of the NatGas/Air
mixture.
If the Calorimeter
detects a deviation of the CV from the desired value, the AccuBlend™
controller automatically adjusts the position of the piston in the POM,
thereby changing the NatGas/Air blending ratio, and re-establishing the
desired CV.
Note:
If the CV of the NatGas as supplied to the plant is always higher
than the minimum acceptable CV, the POM blender would always "dilute"
the NatGas with Air.
If the CV of the NatGas
as supplied to the plant could fall below the minimum acceptable CV, the
POM blender can be switched to "Enrichment Mode". In this mode, the air
supply is turned off, and is replaced with a supply of BTU-rich gas, for
example LP vapor. As before, the NatGas and the LP vapor will be mixed
by the POM blender to achieve the desired CV. The Calorimeter will again
be used to provide a feedback signal to the AccuBlend™ controller to
make adjustments to the blending ratio if and when required.
The switch from
"Dilution" to "Enrichment" can be initiated manually
by the operator, or can be accomplished fully automatically (without operator
interaction). |
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Coke Oven Gas Replacement |
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Situation:
A steel mill operates their own coke plant. Coke Oven Gas (COG) is a
by-product of the Coke-making process and is used to fuel the process.
Occasionally, the Coke
batteries have to be shut down for maintenance and repairs. To start the
batteries back up again, COG is required. However, since the batteries
are
shut down, no COG is being generated.
Solution:
Installation of a POM blender with Automatic Gas Properties Control
(AccuBlend™).
Operation:
The POM blender is supplied with NatGas and with Air (or Nitrogen).
The POM is pre-set to a blending ratio that results in highly "diluted"
NatGas/Air mixture with a CV that resembles the properties of COG.
A Calorimeter at the outlet of the POM measures the CV of the NatGas/Air
or NatGas/Nitrogen mixture.
If the Calorimeter
detects a deviation of the CV from the desired value, the AccuBlend™
controller automatically adjusts the position of the piston in the POM,
thereby changing the blending ratio, and re-establishing the desired CV. |
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Landfill Gas Backup |
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Situation:
The dryers in the paint shop of an automotive manufacturing plant
are supplied with low-BTU Landfill Gas (LFG) as the primary fuel source.
Occasionally, the supply of LFG is
interrupted due to equipment maintenance at the landfill site. Since the
paint process is crucial to the continuous production output of the
plant, a backup gas source is needed.
Solution:
Installation of a POM blender with Automatic Gas Properties Control
(AccuBlend™).
Operation:
The POM blender is supplied with NatGas and with Air. The POM is
pre-set to a blending ratio that results in highly "diluted" NatGas/Air
mixture with a CV that resembles the properties of LFG.
A GraviBlend™-3 gravitometer at the outlet of the POM measures the
properties of the NatGas/Air mixture.
If the gravitometer
detects a deviation of the gas properties from the desired values, the
AccuBlend™ controller automatically adjusts the position of the piston
in the POM, thereby changing the blending ratio, and re-establishing the
desired properties. |
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Digester Gas Enrichment and Backup |
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Situation:
Waste Water Treatment Plants produce "Digester Gas" (DiG) as a
by-product of the waste water treatment. The DiG is used as fuel for
reciprocating internal combustion engines to drive air blowers and/or
electric generators. The air from the blowers is used in the digester
process; the electricity from the generators is used in the plant;
excess electricity is sold to electric utility companies.
The heating value of the
DiG depends largely on the type of waste that is being processed, and
can therefore vary widely. These variations require the engines to be
set up in a very "forgiving" mode, resulting in diminished efficiency
and increased exhaust gas emissions.
Occasionally, the supply of
DiG is
interrupted due to equipment maintenance. This leaves the engines
without fuel, which leaves the digester process without the air from the
blowers, which is needed to stimulate and boost the digester process.
Solution:
Both goals, stabilization of the properties of the DiG as fuel for the
engines, and backup fuel supply for times when DiG is unavailable, can
be covered with the
Installation of a single POM blender with Automatic Gas Properties Control
(AccuBlend™).
Operation:
The POM blender is supplied with NatGas, with Digester Gas, and with Air.
If DiG is available from
the waste water treatment process, the POM blends NatGas and DiG at a
varying ratio that results in very stable fuel gas properties (Calorific
Value) for the blower/generator engines.
If DiG is not available
from the waste water treatment process, the POM blends NatGas and air at
a ratio that results in a mixed gas that allows the blower/generator
engines to operate at their highest efficiency with the lowest possible
emissions.
A gas analyzer at the outlet of the POM measures the
properties of the NatGas/DiG or the NatGas/Air mixture.
If the gas analyzer detects a deviation of the gas properties from the desired values, the
AccuBlend™ controller automatically adjusts the position of the piston
in the POM, thereby changing the blending ratio, and re-establishing the
desired properties. |
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Other Non-Standard Blending
Applications |
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The POM blenders can be used for the
blending of any two dissimilar gasses at (almost) any blending ratio. In
standard POM configurations, the gasses must be compatible with Carbon
Steel, Brass, Aluminum, and Buna N or Viton®.
For more corrosive applications, POM valve
and other components in the gas streams can be manufactured from
Stainless Steel or other corrosion-resistant materials.
Please
contact the factory with your
specific requirements. |
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