What is the difference between bubble humidifers and steam injection humidifiers?
The FiderisTM bubble humidifier is fairly typical of sparger type humidification. The reactant gas is introduced at the bottom of a water reservoir through a frit or diffuser. As the reactant gas bubbles to the top, it reaches thermal equilibrium with the water reservoir and absorbs water from the reservoir. The temperature of the water is controlled to control the exiting dewpoint of the reactant gas. In a steam injection humidifier, the water is flash evaporated on a dry surface an the resulting steam engaged with the reactant gas. Sufficient heat is transferred to the reactant gas so that the reactant gas temperature is raised to that required to entrain all of the steam being generated. This method of humidification results in a saturated gas stream exiting the humidifier at its dewpoint temperature. More information about the differences between the two types can be found in the FAQ section of the steam injection humidifiers.
