Purification Technology Edition: Daily Question [2017-10-25]
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What is flooding? How to avoid flooding? Answer: The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is first necessary to control an appropriate liquid/gas ratio and space velocity. At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tower plates are clean and free of contaminants.
For a tower of fixed diameter, the cross-section through which both gas and liquid phases can flow freely is limited. If the flow rate of either one of them increases to a certain level, the liquid in the downcomer cannot flow downward smoothly ； When the liquid in the pipe rises to the top of the overflow weir on the upper plate, it will spill over onto that upper plate, causing abnormal accumulation of liquid; eventually, this can result in the space between the two plates being filled with foam. This phenomenon is known as flooding, also referred to as tower flooding.
The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is first necessary to control an appropriate liquid/vapor ratio and space velocity (load). At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tray plates are clean and free of contaminants.
Foaming: In the tower, the two phases flow in opposite directions; when the flow rate of one of the phases reaches a certain value, the pressure drop between the upper and lower layers of trays increases to such an extent that the liquid in the downcomer cannot flow smoothly. Once the liquid in the tube rises above the overflow weir of the upper tray, it spills onto that tray – this is known as foaming. In fact, it’s just that the liquid can’t flow downward smoothly, which is why it overflows. Appropriately increasing the plate spacing and reducing the gas velocity can both prevent or reduce flooding.
On the tray, the liquid from the upper tray flows down to the lower tray through the overflow pipe. As it moves downward, it must overcome various resistances, which requires a certain level of liquid to be maintained in the overflow pipe; as a result, the overflow resistance increases and the liquid level rises accordingly. When this increased level prevents the liquid from flowing from the upper tray to the lower tray through the overflow pipe, this phenomenon is known as flooding. Causes of flooding: excessive amount of rising gas and high gas temperature, too large a feed rate to the tower, blockage of the tray or overflow pipe, and unreasonable design or manufacturing of the trays. Addressing the above issues appropriately can prevent flooding.
Answer: The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is first necessary to control an appropriate liquid/gas ratio and space velocity. At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tower plates are clean and free of contaminants.
Liquid flooding: In a tower, the liquid from the upper tray flows down to the lower tray through the overflow pipe. As it moves downward, it must overcome various resistances, which requires a certain level of liquid to be maintained in the overflow pipe; as a result, the overflow resistance increases and the liquid level rises accordingly. When this increased level prevents the liquid from flowing from the upper tray to the lower tray through the overflow pipe, this phenomenon is known as liquid flooding. Causes of flooding: excessive amount of rising gas and high gas temperature, too large a feed rate to the tower, blockage of the tray or overflow pipe, and unreasonable design or manufacturing of the trays. Addressing the above issues appropriately can prevent flooding.
The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is first necessary to control an appropriate liquid/gas ratio and space velocity. At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tower plates are clean and free of contaminants.
The phenomenon of liquid flowing back inside the tower is called flooding. To avoid flooding, it is first necessary to control an appropriate liquid/vapor ratio and space velocity (load). At the same time, it is necessary to prevent the liquid from foaming, improve the purity of the absorbent, and ensure that the tray plates are clean and free of contaminants.
The phenomenon of liquid flowing back inside the tower is called flooding, and at this point the pressure difference across the tower increases significantly. To avoid flooding, it is first necessary to control the appropriate gas-liquid ratio and space velocity (load), while also ensuring that the liquid does not foam, improving the purity of the absorbent, and keeping the tower trays clean and free of contaminants
The phenomenon of liquid flowing back inside the tower is called flooding, and when flooding occurs, the pressure difference in the tower increases significantly. To avoid flooding, it is necessary to control the appropriate liquid/gas ratio and space velocity