The effect of steam dryness on the temperature of steam after pressure reduction
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Technically, steam is used to heat the water, as the site does not have the facilities for a water spray cooling system. Previously, there was concern that the steam coming from the cylinder splitters would have too low a dryness level, so a steam-water separator was installed before the pressure reducing valve. Now that it’s in operation, there’s a problem: the separation of soda from other components is too effective, and once the pressure is reduced, the system overheats, which affects the heat exchange efficiency of the downstream heat exchangers. How should this be handled? It is clearly inappropriate not to carry out separation, as no one can guarantee the dryness of the next wave of steam flow. It’s hard to say what the dryness at the separated outlet will be; it could range from 0.97 to 1. Overheating occurs even when the pressure drops from 6 Barg to 3.6 Barg. Are you forcing me to plug up the soda separation? ;P
The drainage outlet for separating steam from water is equipped with a hydrophobic valve. The current issue is how to determine the dryness degree before depressurization.
I mean replace the soda separator with a steam trap
I understand what you mean: avoid liquid separation by installing more steam traps along the pipeline. However, there is a problem with this approach: the steam trap only removes the water that has condensed, and it cannot separate and remove the water contained in the steam. As a result, the dryness of the steam before pressure reduction might be low, for example, below 0.95. After such pressure reduction, it becomes wet steam, which does not meet the requirements of saturated steam for industrial use.
When using steam heating, it is best to slightly superheat it by within 5 degrees. However, this superheat is highly affected by the dryness degree.