Kettle reboiler illustration

Figure 12-4 illustrates the operation of a debutanizer equipped with a kettle reboiler. The liquid level in the bottom of the lower is determined by the pressure difference between the reboiler and the tower. (As the reboiler vapors vent back to the tower, the reboiler must be at the higher pressure.) The plant operators observed that when they increased the reboiler heat duty beyond a certain point, the lower s AP gauge reading would dramatically increase, indicating flooding. They therefore erroneously concluded that the trays were overloaded. 

The function of reboilers has already been discussed. These components are essentially heat exchangers that are used to transfer heat to bring the liquid at the bottom of the column to its boiling point (refer also to discussions in Chapter 1). The principle types employed are jacketted kettles, simple kettle type reboilers, internal reboilers, and thermo-syphon reboilers. Examples of each type are illustrated in Figure 7. 

The equations for SorePs method will be derived for the case illustrated in Fig. 7-1. The column is assumed to be operating continu-oudy on a binary mixture with the feed entering on a plate between the top and bottom. The column is provided with heat for reboiling by conduction such as steam coils in the kettle the case of the use of live or open steam will be considered later. A simple total condenser... 

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