A drain valve is installed at the outlet of the steam-flue gas heat exchanger; when the load is low, a vacuum can form in the shell and tube assembly, making it impossible to drain water
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As shown in the attached diagram, there is an SGH behind our wet scrubber tower: steam enters and water is discharged. However, the drain valve does not function, so water cannot be drained and the heating effect is poor. Some people say that our load is too low at this time, with the steam input being less than 20%, which results in a vacuum on the steam side inside the shell (in other words, our heat exchanger has too large a capacity). If there is a vacuum in front of the drain valve, then how can water be drained? But I wonder if this is possible I’ve only heard that condensers can create a vacuum – can this be done as well?
Measure the temperature of the steam pipeline; if it is below 100 degrees, there may be a vacuum, while if it is above 100 degrees, there is definitely positive pressure.
It’s impossible that the inability to apply heat is caused by an excessive heat exchange area; if water drainage isn’t possible, increasing the steam supply will surely allow the water to be discharged. There must be some other reason
Yeah, I think so too; it seems like they have introduced the concept of steam turbines and condensers, but in reality it’s very difficult to create a vacuum in such equipment.
Is it possible then that it’s supercooled water? The temperature is below 100 degrees, but the pressure is higher than the saturation pressure
Indeed, there are times when the temperature drops below 60 degrees
That means the steam supply volume is too low; increasing the steam supply volume (for example, by enlarging the diameter of the steam pipe) can solve this problem.
There’s a broken vacuum pump in the picture; is it less sensitive?
The image shows Spayshack. Our design does not include such a vacuum break valve, and we never use one either
Is there a valve in front of the steam trap? If it exists, just remove the trap and take a look; if there is no vacuum, check whether it is due to the trap, a fault, or an inappropriate selection
There are valves; I also want to add a sight glass to check the condition of the water repellent