Split liquid levels indication, foam

Figure 6.4 Split liquid-level indication caused by foam.

Rather, these split liquid levels are a positive indication of foam or froth in the bottom of the tower. 

Many of you may have observed this on a process vessel. We certainly cannot have layers of liquid-vapor-liquid-vapor in the vessel. Rather, these split liquid levels are a positive indication of foam or froth in the bottom of the tower. 

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