According to an analysis by ABB, 70% of all errors in a measurement fall on
the sampling, transport and preparation of the sample.
Sample conditioning - the goals
- Optimization of the total costs when buying and operating the
- Reliable and reproducible readings
These goals can only be achieved if the interaction between analyzer and sample preparation works. The trend observed at the Achema, where possible, to measure optically directly in the process (in-situ), necessitates the extraction of the sample (for example because of the pressure conditions or the dust load).
Compact gas sampling probe PSG Basic
Sample conditioning - the extraction probe
The gas sampling is often carried out in extractive measurements via a probe. Their main task is the filtration of dust and other particles and the avoidance of condensate under consideration of the acid dew points.
Two points often lead to massive problems with the gas extraction:
- on the one hand the housing and the heating of the probe itself and
- on the other hand the transition / connection of the heated line.
If the accurate heating of the probe is ensured, the transition to the heated analysis line can be another weak point:
It is essential to ensure that this is provided with an insulation, without which it can lead to the formation of cold spots and thus to condensation.
A further weak point can be the heated analysis line : Only if the heating cables are led to the end of the cap, it can come here not only to below the acid dew point, but also to block or even the loss of gases.
Sample conditioning - the transfer lines
The basic task is removing gas samples from the gas processing lines and the transfer to the sample conditioning unit. In practice this means laying long flexible lines fixed to the stack as well as holding the temperature from 180 ° C to 200 ° C on the entire route.
The PSG Hybrid Lines establishes the link between the gas sampling probe and the processing in the analysis room and can be configured so that all necessary components for the operation of the probe are brought along the pipeline: from the power supply via the temperature sensor to the calibration gas.
Sample gas conditioning system MAK 10
Sample preparation - cooling and drying
Hheating is carried out during gas extraction and transport so that condensation does not occur. During the preparation the sample gas is now cooled due to the increasingly sensitive measuring cuvettes as well as the cross-sensitivity of the analytical methods with water. Since the water loadings of the gas can fluctuate due to environmental or process conditions, the heat exchanger must be able to react flexibly to these.
To minimize this effect, AGT-PSG has developed a patented heat exchanger concept, which has now been further optimized by further development in the new MAK 10 Twister. The additional peculiarity of the solution lies in its modular design: From a simple 1-way sample gas cooler, it can be gradually expanded up to 4-gas paths, regardless of whether as a “cabinet” version with bevelled display for better readability or
as a 19 “version.