270NH3.MAN.REVD.062019
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Start-Up
Apply power to the unit. Allow the probe filter chamber and NH
3
converter to come up to operation
temperature. This warm-up period is extremely important to avoid condensation, which can cement
particulates to the filter surface and in the converter path.
Only after the unit has come up to full temperature, start the gas sample pump(s) and determine that the
proper amount of sample is being supplied to secondary instrumentation.
Run a calibration cycle to ensure that tubing is properly installed and sealed. A flow meter should be installed
in the cal gas supply line to ensure that at least 10% more gas is being supplied than what is withdrawn as
sample. This calculation should include the sum of the unconverted and converted sample paths. Excess cal
gas is discharged through the probe into the stack.
Charge the accumulator and manually perform a blowback cycle to ensure proper wiring. A slight pulse of
instrument air in the sample tubing will cause a momentary dilution of sample at the analyzers. This is normal
and signifies that a blowback cycle has occurred.
AMMONIA OXIDATION TEMPERATURES
It is suggested that the temperature of the reactor oven be first controlled to 1250°F (677°C). to determine if
satisfactory ammonia conversion efficiencies can be obtained at that temperature.
