Calculation for DA vent orifice
Calculation for DA vent orifice
(OP)
I have a Deaerator (DA) that is emitting tremendous amounts of steam and hence losing money. I have heard and understand an old adage of a "8-12 inch steam stream that is soft and fluffy and not blowing" should suffice for regulating the discharge through the vent.
However, I know the calculation for the orifice size has to do with the makeup requirements for the system, the tank capacity and possibly something else.
I am curious to see if someone could point me in the right direction for sizing a DA vent orifice.
Thanks in advance.
However, I know the calculation for the orifice size has to do with the makeup requirements for the system, the tank capacity and possibly something else.
I am curious to see if someone could point me in the right direction for sizing a DA vent orifice.
Thanks in advance.





RE: Calculation for DA vent orifice
The optimum size of the orifice can best be found by drilling a small hole (1/8" to 1/4") and checking dissolved oxygen in the effuent. Also, observe the water temp to see that it is at saturation temp of the steam within the heater. If the oxygen reading is high or the temp is low,increase the hole size in the orifice and recheck. Repeat until the oxygen is below the guarantee level and the temp rises to steam saturation temp. Bottom line is trial and error. Hope this helps. Later.
RE: Calculation for DA vent orifice
Allbeit I am not trying to refute a manufacturer's procedure to operate their own equipment, I must point to a reference that indicates there is come calculation that can be used to determine size of vent/orifice:
http://www.nrel.gov/docs/fy06osti/39320.pdf
Look at the last sentence of the first paragraph under "How they work."
Anyone else have any ideas?
RE: Calculation for DA vent orifice
Finally, any restriction of the flow, will require a new heat balance. Note the restriction can increase the amount of dissolved oxygen in the outflow of water.
Regards