Flooding deaerator

Although flooding is clearly associated with aeration and deaeration, de-aeration or fluidization tests alone are not sufficient to establish floodability. A long de-aeration time and large bed expansion observed in a simple de-aeration test usually, but not always76, coincide with a high likelihood of flooding. 

Water injection from seawater or fresh water sources contributes to the souring of oil fields with H2S usually resulting in an increase in the corrosion rate, which sometimes requires a complete change in corrosion strategy. These water sources may necessitate biocide injection and will require deaeration to avoid introducing a new corrosion mechanism into the existing system. Tertiary recovery techniques are often based on miscible and immiscible gas floods. These gas floods invariably contain a... 

A consequence of the use of advanced technology in oil production from a reservoir results in increase in the corrosivity of the oil production environment. The extent of corrosion increases because (i) oil, water, and gas are present in the field. Seawater or fresh water is injected downhole to drive oil out of formation. As time passes, the amount of water to the amount of oil increases and the degree of internal corrosion increases. Water injection from seawater or fresh water sources causes souring of oilfields with H2S and increases in corrosion rate. These water sources require biocide injection and deaeration to avoid the introduction of new corrosion pathways into the existing system. Tertiary recovery techniques involve miscible and immiscible gas floods that may contain as much as 100% CO2. This leads to high corrosivity of the fluids. 

Flooding or flushing when a rathole collapses it entrains air, becomes fluidized and the material floods through the outlet uncontrollably fine powders such as pigments, additives and precipitates that tend to rathole/insuflicient residence time in hopper for deaeration. 

Equation 1 above stales that a tray will become less efficient due to incipient jet flood when the pressure drop per tray, expressed in inches of liquid, equals 22% to 25% of the tray spacing. The inches of liquid term assumes the liquid is deaerated. Of course, the liquid in the downcomers and on the tray decks is closer to a froth than to a flat liquid. The more highly aerated the liquid is (i.e. the more foamlike it becomes), the greater will be the depth of liquid corresponding to a measured external pressure drop. Hence, liquids which foam in distillation columns (such as dirty amine and ethane-rich fractionators) reach their incipient jet flood point at pressure drops below the 20% indicated in Equation 1. 

This means volume is inversely proportional to pressure. As the pressure of the flowing steam declined, the steam s volume increased. The larger volume of steam flow resulted in a higher vapor velocity to the stripper trays 1 through 3. This caused the bottom stripper tray to flood. After a few minutes, the flooding forced cold BFW out of the atmospheric vent. The level in the deaerator drum then fell. The cold BFW level-control valve opened further, driving down both the temperature and the pressure in the deaerator drum. The volume and the... 

As I ve described in my book. Troubleshooting Process Plant Control, any time the steam inlet control valve becomes fully open, the deaerator temperature, pressure, and water level will become unstable and the deaerator stripping section will flood. Flood in the sense that boiling water may erupt from the atmospheric vent. 

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