BFS Industries’ packed column type deaerators utilize two distinct stages to accomplish the removal of the dissolved gases from the feedwater:
1. The pre-heater section
2. The stainless steel packing section
It is essential that the first stage (pre-heater) heats the feed water to a temperature approaching that of the deaerator operating steam pressure. The heated and partially deaerated water then enters the second stage (packing section), where contact time with the counter-current scrubbing steam is maximized. This forces the remaining traces of oxygen and carbon dioxide to be released from the liquid.
Packed Column Deaerator Operation
Stage One: Pre-heater Section
Incoming water enters the deaerator through spring loaded spray valves, directed downward into the steam atmosphere in the first stage pre-heater section.
In the BFS packed column type deaerator, this pre-heater section is fully enclosed in stainless steel. Here the water is heated to within a few degrees of the steam temperature in the deaerator by spraying the water in a uniform, thin, continuous film. The surface tension of the liquid is broken, which facilitates the heating as well as the release of most of the non-condensable gases.
Stage Two: Stainless Steel Packing Section
The pre-heated water, containing traces of dissolved gases, then flows into the second stage where the liquid constantly changes direction as it flows down through the high efficiency stainless steel packing. This assures the maximum contact time between the steam and water, and forces the remaining traces of oxygen and carbon dioxide to the surface of the liquid where they can be liberated from the water. The process continues until the water reaches the bottom of the packed column.
The steam enters this stage at the base of the packed column and flows upward through the packing. The counter-current steam flow shakes loose the remaining dissolved gases, separating them from the liquid. Very little steam is condensed here, as the incoming pre-heated water has a temperature approaching that of the steam.
The water leaving this stage – now completely deaerated and heated to the steam temperature corresponding to the saturated steam pressure within the vessel – falls into the storage section, where it is ready for use.
A reduction in temperature and pressure in the vent condenser area is created as the entering water condenses the steam atmosphere. The steam flows naturally up through the packed column toward the lower pressure area of the vent condenser, carrying with it the liberated gases. Here most of the steam is condensed in the heating process, and the remainder carries the residual gases through the vent to the atmosphere.
Packed Column Deaerators from BFS Industries
BFS Industries offers packed column type deaerators as part of our ZER-O-PAC line of deaerators. Our team can evaluate your system and help determine whether a packed column type deaerator is right for you. Contact us for a custom-designed solution.