Perma Pure’s Multitube Dryer for High Flow and High Capacity Drying Applications
Perma Pure PD-Series™ gas dryers are multi-tube Nafion™ tubing gas sample dryers designed for high flow, high performance gas drying applications where having a larger amount of of membrane surface area could improve your drying performance. Multiple tubes are bundled together in parallel to form a high capacity dryer. These dryers can be used to dry to -45°C without removing other compounds. Applications for PD-Series gas dryers include gas sample conditioning for continuous emissions and process monitoring. In these applications, sample gases flowing through the Nafion™ tubing are dried without removing any of the sample analytes. PD-Series gas driers can also be used in small scale process applications. Process applications take advantage of one or more of the unique properties of Nafion™ polymer: highly efficient and selective moisture exchange, ion exchange capabilities, and extreme corrosion resistance.
- Flow rates up to 40 l/m
- Lower pressure drop for comparable flow rates
- Faster response time due to shorter flow path
- Operating temperatures to max. 120° C
- Operating pressures to 45 psi (absolute)
- Straight or flexible configuration
- Corrosion resistant
- Standard dew points to – 25° C, with lower values possible (contact factory)
- No loss of analytes
- No moving parts
Principle of Operation
PD-Series dryers consists of a bundle of 0.030″ O.D. Nafion™ tubing housed within a single large tube shell. Feed gas flows within the Nafion™ tubing while water vapor absorbs into the tubular membrane walls and is removed. Moisture permeating the tubing is carried away by a dry purge gas within the shell that flows counter-current to the feed. Purge gas should be instrument quality air (-40°C dew point) or nitrogen flowing at two to three times the sample flow rate.