When header pressure variations are small, temperature compensation is sometimes omitted since temperature changes more slowly than pressure.
Steam condensate removal is most commonly achieved by traps—devices that, in effect, are very simple level controllers. Many plants have experienced the need for high maintenance with these. Sometimes enough steam leaks through to impair the accuracy of steam-consumption estimates based on steam flow metering. In addition, as pointed out by Mathur,9 a rapid closure of the steam valve may cause a vacuum in the shell and pull back condensate through the trap with possible hammering and vibration in the shell. As a result, some reboilers, particularly large ones, are now equipped with condensate seal pots. These pots then have conventional level controllers.
Two practical problems are associated with the selection of condensate removal valves: (1) in sizing calculations allowance usually must be made for some flashing, and (2) the pressure drop increases with flow rate since reboiler shell pressure increases with load. This means that the installed valve flow
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