(26d) Considerations of Temperature Measurement in the Claus Thermal Reaction Furnace

Abstract

Considerations of Temperature Measurement in the Claus Thermal Reaction Furnace

Steve Croom

Delta Controls Corporation

Shreveport, Louisiana

There are numerous factors to consider in obtaining accurate and reliable temperature measurement under the varying conditions of Claus Reaction Furnace operation over the long term.

Both thermocouples and Infrared Pyrometry have distinct advantages as well as drawbacks, which must be considered in the design, selection and installation of the equipment in this critical service.  These factors must be clearly understood in order to realize the benefits and to avoid possible pitfalls of each measurement technology.

Position, location and attention to detail during installation of the instruments are critical to assure that the measurements are meaningful and provide the utmost protection against damage to the vessel.

Positioning of the devices must consider the vessel design, the burner type and, if possible, a CFD modeling of the vessel to determine the most effective installation locations; this avoids positions in relative “cold spots”, such as too near the burner, behind choke rings or downstream of inlet feed streams,  all of which could produce inaccurate readings. 

For infrared pyrometers, awareness of the effects of gas composition during various phases of operation can be critical in avoiding erroneous low temperature readings and is particular true when attempting to measure the gas temperature vs. that of the refractory hot face.

In addition to the normal operating conditions, consideration must be given also to the low temperature refractory dry-out cycles, as well as start-up and shutdown to assure reliable and meaningful readings.