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DKL Engineering, Inc.
Instrumentation - O2 Concentration
June 4, 2006
After the gas cleaning system, the SO2 concentration is unknown as well as the O2:SO2 ratio. Air dilution may be required to achieve the desired conversion in the converter. On-line continuous measurement of SO2 and O2 may be required to control the amount of dilution air being added to the process.
An instrument that draws a gas sample from the main process stream is preferred over an in-line instrument because of the problem of maintaining the instrument. If the instrument is in-line it often cannot be removed during operation for maintenance, calibration or repair without a complete plant shutdown.
At Westcoast and Noranda an in-line probe was used sampling directly in the process gas stream. The rubber O-ring seal deteriorated and allowed process gas to damage the electronics resulting in an instrument failure.
|AMETEK||Zirconium Oxide Electrochemical Cell||1 to 100% O2||WDG-IVC||Sample drawn from
process stream and delivered to analyzer
Aspirator Air: 10 to 20 SCF/h @ 15 to 100 psi
Electrical: 700 VA (max) Sensor
360 VA (max) Controller
Accuracy: ± 2% of measured value
In-situ analyzers are not recommended because of the requirement for a complete shutdown in order to remove and maintain the probe.