(11) Corrections shall be made for temperature, oxygen saturation
of the water, and the relative transfer coefficient of the water
and then the pounds of oxygen dissolved at standard conditions of
20 degrees C 68 degrees F, tap water, and "O" ppm dissolved
concentration shall be computed.
(12) The efficiency of the aerator shall be determined by
dividing the kg pounds of oxygen dissolved per hour under standard
conditions by the input wattage horsepower.
(13) After tests have been made to prove that the oxygenation
capacity at maximum submergence of the aerator(s) meet(s)
specified requirements, tests shall be repeated to establish
oxygenation capacity at liquid levels 75 mm and 150 mm 3 inches
and 6 inches below maximum submergence. The tests shall be those
specified herein.
(14) Should aerator(s) fail to produce the oxygenation capacity
required, the test series shall be repeated.
(15) If the required oxygenation capacity is not produced after
two test repetitions, the Contractor shall either correct the
defective unit(s) or replace them with new unit(s), and the test
procedure shall be repeated as set forth herein, until
satisfactory units are obtained.
b.
Mixing Test for Mechanical Aerator:
(1) Mixing Velocity Test: Mixing test shall be conducted in the
same tank and at the same time as the oxygenation capacity test.
(a) Velocity measurements shall be made throughout the tank when
aerator(s) is in service under actual operating conditions to test
for complete mixing of tank contents.
(b) Measurements shall be taken at the quarter points of each
tank wall, 0.60 m 2 feet from the wall, and at the levels of the
sample pumps used in oxygenation capacity tests. Minimum velocity
shall be 0.18 meters per second 0.6 fps. Measurements shall be
taken with a Price current meter.
(c) Should any of the velocity measurements fall below the
specified minimum velocity, the test shall be repeated.
(d) If the specified minimum velocity is not produced after two
test repetitions, the Contractor shall either correct the
defective unit(s) or replace them with new Unit(s), and the test
procedure shall be repeated as set forth herein, until
satisfactory units are obtained.
2.19.2
Fine Bubble Diffusers
2.19.2.1
Porous Ceramic Tube Diffusers
a.
Oxygen Absorption for Porous Ceramic Tube Diffusers: Prior to
starting production of porous ceramic tube diffusers, the
manufacturer shall furnish three sample tubes of the type to be
furnished for installation. The sample tubes shall be tested for
oxygen absorption by the manufacturer and shall be selected at
SECTION 11375N
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