Instrumentation - O2 Concentration
June 4, 2006

Introduction

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.

Installation

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.

Instruments