Condensate Receiver Vent

[jrussell]

I am trying to eliminate overheating in a small mechanical equipment room.

A 200degF cast-iron ITT/Bell&Gossett condensate receiver is located in the room, it has a 2" open vent line that runs a few inches up and over and then dumps near a floor drain. The vent line continuously releases water vapor and small amounts of liquid water into the room.

The room also contains some water treatment equipment, which has electronics we are trying to keep below 85degF.

My first approach would be to insulate the condensate receiver. However, I would also like to eliminate the latent and sensible load from the open vent line. Thus, I am looking into routing the vent line approximately 20 ft, through another room, to outdoors.

Any ideas for routing condensate receiver vent piping? ie maximum length, slope, sizing, etc.? Or is this a bad idea? I looked in the Bell and Gossett O&M manual, and all they say is "Install a vent pipe to atmosphere.Pipe to be of size of vent port on unit."

Thanks in advance for your feedback.

 

[Joesteam]

Keep the pipe 2" and slope back to the reciever. This way you will get just flash steam out of the vent (unless you have failed traps), and the liquid will drip back to the pump. Be sure the vent does not point to any area where the steam flow may harm people.

 

[KenRad]

jrussell,

A couple of things:

Is there a separate overflow on this receiver, or is the line that you are thinking about extending supposed to be acting as an overflow? The receiver should have both. The vent keeps from pressurizing the tank with steam from failed traps, and the overflow prevents condensate backup in your system (and pressurizing the tank) if your pumps fail. If there is no overflow, I would run a separate vent line, and use the existing line as an overflow, but add a p-trap to it to keep the flash steam from discharging into the space.

Secondly - Have you checked for failed traps? If you're seeing a lot of steam right now and your tank is very hot, you might have one or more traps blowing steam.

---KenRad

 

[quark]

You can reduce water carryover if you keep the vapor velocity below 10m/s. Secondly, you should discharge the condensate regularly to avoid overflow. 20ft of pipelength may not be very critical but check the pressure drop of flash steam with your flow rates. The link below can help you.

http://www.spiraxsarco.com/learn/default.asp?redirect=html/10_2_01.htm

Note that if the pressure drop is significat then back pressure on the system increase overall pressure of the condensate recovery tank.

If everything is ok then I will follow Joesteam's suggestion.

Good luck,