HIPERVAC™
You can be confident in your selection of NATCO deaeration products. With over 50 installations worldwide in the last 20 years, the HiperStrip and HiperVac deaerators provide reliable and consistent water deaeration. The units can be supplied as stand-alone, or as part of a full water flood system.
Vacuum deaeration is the most common deaeration technology being used in the oil and gas industry today. Packed towers are continuously evacuated by specially selected vacuum systems, which drives the mass transfer process of the oxygen from the liquid to the gas phase. Our design is based on an economic balance between tower diameter, number of stages, packed bed heights and vacuum pump size. For long term reliable operations the system is constructed with corrosive resistant tower internals intended to maximize mass transfer and give effective distribution and redistribution of the liquid phase.
The first stage of the tower performs bulk removal of oxygen at a relatively high pressure, and the second stage achieves final removal at a lower absolute pressure (higher vacuum).
Two stages of mass transfer packing are typically used. At any given temperature, it is necessary to achieve a certain pressure to achieve the desired oxygen residual concentration (typically 20 – 50 ppb from the packing). This is typically 25 mm Hg absolute for warm water applications.
Theoretically, it is possible to use a single stage tower and extract the entire vapor at this low pressure, but the necessity of using an ejector to achieve the low pressure required would mean having to pump large volumes of motive air. It is more efficient to extract the bulk of oxygen at higher pressure in the first stage without an ejector, leaving a relatively light duty for the lower pressure stage.
The interstage seal is the most important component in any vacuum deaeration system. It is required to maintain a pressure differential between the stages of the tower. NATCO’s system uses an upcomer/seal pot arrangement, which guarantees a minimum water hold up, and therefore pressure seal at all flow rates, even when there is no flow.
See also HiperStrip technology for water deaeration where natural gas is available.