Condensers condensate backup effect

Sub-cooled condensate Figure 8.3 Effect of condensate backup. 

Effect of condensate backup. When the condensate level in an exchanger increases, the area of the condenser devoted to subcooling the condensate increases. But the area of the exchanger available for condensing decreases. That is bad ... 

However, the number of tubes exposed to the condensing steam is also reduced. This forces the steam to condense at a higher temperature (as discussed in Chaps. 8 and 13). In effect, the condensate backup has reduced the surface area of the condenser, available to condense the steam. The higher the condensation temperature of the steam, the higher the condensation pressure of the steam. Just like the deaerator I described in Chap. 15. 

In one instance the effect of steam condensate backup was clearly observed during a unit turnaround. As shown in Figure 12-10, the rust layer on the inside of the channel head of a reboiler showed clearly where the condensate level normally ran. This was a positive indication that 20% of the heat-transfer surface area of the reboiler was waterlogged and, therefore, useless. Steam condensate backup can be due to one of the following ... 

Figure 13.3 The effect of vapor lock is to promote condensate backup and...

---