10-04-2017, 08:13 PM
Working principle
Deaerator
A
deaerator
is a device that is widely used for the removal of oxygen and otherdissolved / non condensable gases from the feed water to steam-generating boilers. Inparticular, dissolved oxygen in boiler feed waters will cause serious corrosion damage insteam systems by attaching to the walls of metal piping and other metallic equipment andforming oxides (rust). Water also combines with any dissolved carbon dioxide to formcarbonic acid that causes further corrosion. Most deaerators are designed to removeoxygen down to levels of 7 ppb by weight (0.005 cm /L) or less.
There are two basic types of deaerators, the tray-type and the spray-type
The
tray-type
(also called the
cascade-type
) includes a vertical domed deaerationsection mounted on top of a horizontal cylindrical vessel which serves as the deaeratedboiler feed water storage tank our deaerator is a tray type deaerator.Tray type deaerators are generally considered the superior choice for most applications.These units use stainless steel for all internal surfaces which come in contact withundeaerated water. Residence time for undeaerated water inside a tray type deaerator islonger, providing more efficient deaeration, particularly where wide load swings occur. Alarge diameter hinged door affords easy access to internal trays and spray tubes formaintenance and replacement. Although tray type deaerators require a larger initialinvestment, the benefits in efficiency and reduced cost of maintenance tend to pay forthemselves quickly The
spray-type
consists only of a horizontal (or vertical) cylindrical vessel which servesas both the deaeration section and the boiler feed water storage tank.
