without overheating or excessive vibration. The initial operation of the
blower driver and the conduct of the field tests shall be under the
supervision of the plant manufacturer. The Contractor shall supply such
labor and materials as may be necessary to properly perform the tests.
During the tests, operating data shall be taken at regular interval and
incorporated in a report. Data readings shall be based on plant meters,
gages and instruments, and shall include the following:
a.
Air volume
b.
Air inlet and discharge pressure and temperature
c.
Motor amperes
d.
Motor kilowatts
e.
Bearing temperatures
f.
Stator temperatures
g.
Lubricating oil pressures and temperatures
h.
Lubricating oil cooling water temperatures
3.10.3.4
Diffusers
Performance tests shall be conducted on the diffusers in the field.
a.
Oxygenation Capacity Tests:
Tests shall be performed as follows:
(1) The aeration tank shall be thoroughly cleaned and then filled
with fresh tap water.
(2) The temperature of the fresh water shall be as close to 20
degrees C 68 degrees F as possible.
(3) Submersible sample pumps shall be installed at three
operating depths, 2.4 m, 1.8 m, and 1.2 m 8 feet, 6 feet, and 4
feet depths at two selected locations in the basin on opposite
sides of the tank, one at 1/4 the distance from center of tank and
the other at 3/4 the distance from center.
(4) A catalyst, chloride or sulfate, shall be dissolved in the
tank contents, with the diffusers working to insure mixing, to a
minimum concentration of 2 mg/1 of cobalt ion.
(5) After the tank has reached a steady state condition for 30
minutes, a sodium sulfite solution, which removes the D.O. shall
be released uniformly into the tank contents. For a liquid having
an initial D.O. concentration of 10 ppm, approximately one pound
of dry sodium sulfite shall be provided per 3,780 L 1,000 gallons
of liquid per test. (This will provide an excess of sodium
sulfite to compensate for oxidation during mixing.)
(6) As the D.O. rises in the tank, size samples, one for each
depth at each location, shall be drawn at one to five minute
intervals. Interval shall be selected to obtain at least six sets
of samples between 10 and 90 percent saturation. The D.O. shall
be run by the Azide Modification of the Iodometric Method as
SECTION 11375N
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