be actuated by a protected diaphragm. The diaphragm shall be a readily
adjustable weighted type or compression spring type of ample area to allow
sensitive control of the gas pressure. The valve shall be capable of
passing [_____] cubic meters cubic feet of gas at a pressure loss not to
exceed [_____] Pa inches water column.
2.2.9
Pressure controls shall be provided to maintain proper distribution of gas
flow on a priority basis to the [compressed gas sludge mixing system,] [gas
storage tank,] digester heater, and the waste gas burners, respectively.
2.2.10
Digester Gas Piping
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NOTE: If removal of hydrogen sulfide gas, present
in some anaerobic sludges, is desired, then iron
oxide impregnated wood chip filters should be added
to the gas piping system.
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Pipe shall be installed with a minimum slope of 20 mm per meter 1/4 inch
per foot toward drip traps and sediment traps.
2.2.11
Digester Gas Storage
A digester gas storage tank, gas compressor, controls, and appurtenances
shall be provided as required for the storage of digester gas.
2.2.11.1
Storage Tank
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NOTE: Design of supports should be according to TI
809-01 for windload and snowload design. Specific
site information on wind and snow loadings must be
included in the design. Provide seismic details, if
a Government designer (either Corps office or A/E)
is the Engineer of Record, and show on the drawings.
Delete the bracketed phrase, in the penultimate
sentence, if seismic details are not provided.
Sections 13080 SEISMIC PROTECTION FOR MISCELLANEOUS
EQUIPMENT and 15070A SEISMIC PROTECTION FOR
MECHANICAL EQUIPMENT or 15070N MECHANICAL SOUND,
VIBRATION, AND SEISMIC CONTROL, properly edited,
must be included in the contract documents.Other
types of storage, other than the expensive
relatively high pressure spherical gas storage tank
and supports, should be considered. Digesters with
gas holder covers or cylindrical steel tanks with
adjusting covers, which supply gas at constant
pressure at variable volume, generally supply
digester gas at low pressures but at pressure
sufficient to operate many boiler burners. A small
auxiliary compressor may be added, if required, to
boost gas pressure.
**************************************************************************
The gas storage tank shall be capable of storing [_____] cubic meters cubic
feet of gas operating between [_____] kPa maximum and [_____] kPa minimum
SECTION 11380
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