Gas Sample Preparation
Gas Analyzers require a clean, dry sample to produce accurate and reliable results. Filters remove entrained particles, but removing moisture from a sample without affecting the analyses is not so simple.
PermaPure’s gas dryers are a superior alternative. They have no moving parts, require no maintenance, and continuously and highly selectively remove water from gas samples without affecting analyses, reaching final dew points as low as -45°C.
Powered by Nafion™ tubing, Perma Pure gas dryers selectively remove water from a gas sample. This selectivity for water vapor allows our dryers to remove more moisture than other gas drying solutions, while keeping analytes in the gas sample.
Monotube Dryer Series (MD-Series) gas dryers contain a single Nafion™ tube. The MD-Series can dry a gas to humidity levels as low as –40 °C dew point and is ideal for applications with flow rates up to 4 lpm.
How it Works
Flow your sample gas through the Nafion™ tubing and flow a dry purge gas outside the Nafion™ tubing, countercurrent to the sample gas flow.
While the partial pressure of water in the purge gas is less than in the sample gas, Nafion™ polymer will selectively transfer water and water vapor from the sample gas across its membrane and into the purge gas flow, yielding a drier sample gas at the sample gas output.
Nafion™ Polymer Selectivity
Nafion™ tubing is highly resistant to chemical attack and exhibits highly selective absorption and transfer of compounds. Most substances completely retained in the sample. Although they do not attack or damage the Nafion™ tubing, some polar organic substances are absorbed and consequently lost from the sample flow path. Ammonia and amines are also absorbed and lost to some degree, for which our scrubbers may be able to help.
