Condensate drum balance line

One important feature of Fig. 8.6 is the condensate drum balance line. Note, that this line is connected below the channel head pass partition baffle. This ensures that the pressure in the channel head, below the pass partition baffle, and the pressure in the condensate drum, are the same. If these two pressures are not identical, then the level in the condensate drum cannot represent the level in the channel head. For this reason, never connect the condensate drum vapor space to either the steam supply line or the top vent of the reboiler s channel head. 

Condensate drum balance line Used to connect the channel head of a steam reboiler to the condensate drum for pressure balance. 

One important feature of Fig. 11.6 is the condensate drum balance line. 

Venting the channel head through the balance line shown in Fig. 8.6 will prevent an excessive accumulation of C02. This is done by continuous venting from the top of the condensate drum. For every 10,000 lb/h of steam flow, vent off 50 lb/h of vapor through a restriction orifice, placed in the condensate drum vent. This is usually cheaper than controlling reboiler steam-side corrosion, with neutralizing chemicals. 

One such turbine, in a refinery near London, would not drain properly, In order to push the condensate out of the turbine case, the operators were forced to raise the surface condenser pressure from 100 to 250 mm Hg (i.e., 20 in of mercury vacuum, in the American system). Note that the balance line shown in Fig. 8.11 keeps the pressure in the turbine case and the condensate drum, into which the turbine case is draining, both equal at the same pressure. 

Flooded condenser schemes shown in Fig. 17.5a to c and f can be used instead of coolant flow variations. In such cases, the inerts normally leave finm the top of the condenser instead of the reflux drum (Fig. 17.8e). If the reflux drum is not flooded, a pressure balance line must be included otherwise, a stable pressure will be impossible to keep in the reflux drum. An overflow line should also be included in this arrangement. 

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