Galvanic Applied Sciences 943-TGS-CE, Руководство по эксплуатации

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Revision 5 42 August 2021
Figure 18: Sample Probe
Sulfur condensing on the probe’s ‘cold finger’ is hydrostatically returned to the process
stream and does not enter the sample probe. Air flow to the sample probe condenser is
controlled via a solenoid valve. This solenoid can be controlled with either a measurement
of the temperature of the sample gas entering the analyzer sample handling system or with
a measurement of the sulfur vapour concentration in the sample gas entering the
measurement cell. If the temperature of the incoming sample gas or the sulfur vapour content
of the sample gas inside the measurement cell exceeds a user-set value, the solenoid will
switch on. The condenser control point (either sulfur vapour concentration or probe
temperature) can be configured in the web GUI – refer to Section 5.4. The Condenser
Cooling Air Adjust Valve allows the user to control the flow rate of the instrument air used
to cool the condenser ‘cold finger’ section of the sample probe.
The concentration of sulfur vapour in the process sample gas that makes it into the probe
and into the measurement cell is measured and displayed on the analyzer display as Sulfur
Vapour (Svap)
. The Condenser Cooling Air Adjust Valve can be adjusted to reduce the
sulfur vapour concentration. There is normally a long time constant associated with this
adjustment. Several factors can impact the temperature of the gas exiting the probe. Factors
that affect the temperature of the gas exiting the probe include:
• Changes in process gas temperature
•
Changes in cooling air temperature
•
Changes in the process gas sample aspiration rate
• Elapsed time since a probe back-purge
• Duration of a probe back purge.