[_____] psig maximum and [_____] psig minimum pressure. The tank shall be
cylindrical above ground tank with supports designed to withstand dead
shell load plus a [_____] km/hour mph wind load and a [_____] kPa psi
snowload. Seismic details shall be in accordance with Sections 13080
SEISMIC PROTECTION FOR MISCELLANEOUS EQUIPMENT and [15070A SEISMIC
PROTECTION FOR MECHANICAL EQUIPMENT] [15070N MECHANICAL SOUND VIBRATION,
AND SEISMIC CONTROL] [as shown on the drawings]. The tank shall be air
tested in accordance with ASME BPVC SEC VIII D1 to 125 percent of the
design maximum pressure.
2.2.11.2
Compressor
A reciprocating type electric motor driven gas compressor, capable of
compressing [_____] cubic meters cubic feet of digester gas per minute at
[_____] kPa psig to a maximum operating pressure of [_____] kPa psig, shall
be provided. Compressor components shall be stainless steel or equally
noncorrosive materials. Motor shall conform to NEMA MG 1. Controls shall
conform to NEMA ICS 1, NEMA ICS 2, NEMA ICS 3, NEMA ICS 4, NEMA ICS 6, UL
845, and UL 508. Electric controls shall be provided as required for
automatic operation of the compressor. Control panel shall include circuit
breaker, magnetic starter, and manual-off-automatic selector switch. Power
supply to the control panel shall be [_____] volts ac, [_____] phase, 60 Hz
and shall be equipped with thermal overload protector with manual reset.
All electrical wiring and motors shall be explosion-proof and be installed
according to NFPA 70. Panel shall be NEMA 250, Type 7.
2.2.11.3
Pressure Relief Valve
A pressure relief valve shall be provided on the gas storage tank. A stop
valve, locked open except for maintenance shall be provided between the gas
storage tank and the pressure relief valve. Sediment traps and drip traps
shall be provided in gas lines at the base of the tank. Pressure controls
for gas distribution shall be provided. A remote pressure indicator shall
be provided in the compressor building to indicate tank pressure [in kPa psi
gauge].
2.3
DIGESTER HEATING SYSTEM
**************************************************************************
NOTE: Boilers providing building radiation and
digester heating operate at 71 to 82 degrees C (160
to 180 degrees F). Hot water to heat exchanger is
mixed to maximum 66 degrees C (150 degrees F) to
prevent caking on sludge tubes.
**************************************************************************
2.3.1
System Performance Requirements
A complete system shall be provided for automatic control of the digester
operating temperature at 35 degrees C 95 degrees F, within plus or minus
0.3 degrees C 0.5 degrees F, by means of an external sludge heating system.
The digester heating system shall have a minimum sludge heating capacity
of [_____] kW Btu/hr based on heating [_____] L/second gpm of sludge from
digesters operating at 35 degrees C 95 degrees F. Boiler shall be fire
tube hot water boiler with maximum operating pressure of 207 kPa 30 psig,
with boiler, burners, draft fans, combustion safety controls and equipment,
breeching and stacks, fuel system, and fittings and accessories in
accordance with Section 15561A CENTRAL STEAM GENERATING SYSTEM-COMBINATION
GAS AND OIL FIRED. Draft fan shall be designed for corrosive application.
SECTION 11380
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