PermSelect® membrane air/gas humidifiers can be used effectively to humidify gases for applications including fuel cells, environmental air/gas humidification, reactant gas humidification, environmental chambers, and respiratory gas humidification in the laboratory. Due to the high permeability of water vapor in silicone, and the large membrane surface area exposed to the gas stream, substantial amounts of water vapor can be passively added to your gas stream without need for boiling water or bubbling your gas through water.
How to humidify a gas stream using a PermSelect® membrane gas humidifier? Humidifying your gas stream is very simple as illustrated in the gas humidification system figure shown below. Your air or gas stream enters a port on one end cap of the PermSelect®membrane gas humidifier and flows through the lumens of the silicone hollow fibers. Water fills the shells side of the humidifier (outside of the hollow fibers), and because water can permeate very easily through silicone, water is transferred through the hollow fiber walls into the lumens, thereby effectively humidifying your gas stream. Note that if the gas flow rate is high enough, cooling of the water in the module may occur due to evaporative cooling, which in turn may reduce the water temperature and thereby the amount of water that evaporates. In such case it is recommended to heat the water in the module, either by recirculating the water as shown in the diagram below, or placing the module in a heated environment.
There are many advantages to using PermSelect® membrane gas humidifiers for gas stream humidification over bubble humidifiers including: bubble humidifiers require constant reloading with water while PermSelect® membrane gas humidifiers refill automatically as water evaporates. Bubble humidifiers are limited in humidification capacity whereas PermSelect® membrane gas humidifiers can be easily scaled up to the required humidity levels by increasing the membrane module size. Bubble humidifiers can “rain out” and flood gas stream lines while PermSelect® membrane gas humidifiers are stable keeping liquid and gas in separate compartments. Moreover, bubble humidifiers must be used in an upright orientation whereas PermSelect® membrane gas humidifiers can be used in any orientation. Finally, PermSelect® membrane gas humidifiers can be more compact (low holdup volumes) and can be used at much higher gas stream pressures compared to bubble humidifiers.
Air or a gas stream enters a port on one end cap of the membrane gas humidifier and flows through the lumens of the silicone hollow fibers. Water fills the shells side of and permeates into the lumens thereby humidifying your gas stream.
View a short video demonstrating how to use a PermSelect membrane module to humidify your gas stream.