Galvanic Applied Sciences 943-TGS-CE, Operation Manual

Page: 16 / 158

Revision 5 16 August 2021
Figure 1: Model 943-TGS-CE
1.4 Sample Handling System
The Analyzer system utilizes a close coupled mounting arrangement of the measurement cell
block to the tail gas process sampling point to minimize the sample handling system length. The
short length allows for analyzer response times to be optimized while sample transport problems
are mitigated. A small volume of tail gas sample is drawn through the measurement cell by use
of an air-driven aspirator where the concentrations of the various species are determined
photometrically.
The measurement sample is drawn from a central point of the process duct using a specifically
sized sample probe . After measurement, the process sample (mixed with the aspirator drive
air) is vented to the wall of the process duct. The concentric chamber design of the sample
probe provides both the sampling and venting of the tail gas sample through a single sampling
point on the process duct.
The sample probe incorporates a mechanism for reducing the dew point of sulfur vapour in the
sampled gas stream. Instrument air can be introduced to provide an exposed cool surface to
the incoming sample gas. Excess condensed sulfur is hydrostatically returned to the process
duct. The sulfur vapour concentration is measured and displayed on the analyzer display. The
sulfur vapour concentration is useful for system troubleshooting.