Perma Pure MD™-Series gas sample dryers use exclusive Nafion™ selectively permeable membrane tubing to continuously dry gas streams removing only water vapor. These dryers operate over a wide range of temperatures, pressures and flow rates, and dry to dew points as low as -60°C.

Product Feature

• Flow rates up to 4 l/m
• Operating temperatures to max. 120° C
• Operating pressures to 100 psi (absolute)
• Straight or coiled configuration
• Corrosion resistant
• Standard dew points to – 25° C, with – 60° C possible in special cases (contact factory)
• No loss of analytes
• No moving parts
   

Principle of Operation

MD-Series gas dryers transfer moisture from one gas stream to a counter-flowing purge gas stream, much like a shell-and-tube heat exchanger transfers heat. Water molecules permeate through the Nafion™ tube wall, evaporating into the purge gas stream. The water concentration differential between the two gas streams drives the reaction, quickly drying the air or gas. Purge gas should be dry (-40°C dew point) air or other gas. If no dry gas is available, a portion of the gas dried by the MD-Series dryer can act as the purge gas in a split-stream or reflux method. Visit the Purge Gas Configurations page to learn more about the purge methods Perma Pure customers deploy in their equipment.