Formula for vent diffuzer sizing
Formula for vent diffuzer sizing
(OP)
I am looking at sizing a steam venting diffuser to dissipate steam from high pressure to atmospheric.
The diffuser will have a diameter of 24" with upstream pressure of 284 kpa. If we were to vent the steam through perforated holes (32mm) drilled into the 24" diffuser wall, how many holes do we need to drill, assuming the flow is chocked. Note that the end of the diffuser is capped. I need to find the correct formula - whether to use the folrmula in Perry (Perry's Chem Eng'g Hand Book 7th ed. Eqn 10-26 for critical flow conditions) or the one in Crane (eqaution 1-11). The problem is that there is a discrepancy of about 23% in the calculated flow between the two formulas.
The diffuser will have a diameter of 24" with upstream pressure of 284 kpa. If we were to vent the steam through perforated holes (32mm) drilled into the 24" diffuser wall, how many holes do we need to drill, assuming the flow is chocked. Note that the end of the diffuser is capped. I need to find the correct formula - whether to use the folrmula in Perry (Perry's Chem Eng'g Hand Book 7th ed. Eqn 10-26 for critical flow conditions) or the one in Crane (eqaution 1-11). The problem is that there is a discrepancy of about 23% in the calculated flow between the two formulas.





RE: Formula for vent diffuzer sizing
What is your goal here.....noise reduction.....or moisture separation?
Dave
RE: Formula for vent diffuzer sizing
RE: Formula for vent diffuzer sizing
RE: Formula for vent diffuzer sizing
I'm just a home owner--anyone have a suggestion? Need to change high efficiency furnace venting to front of house and wife worried about the appearance of the billowing steam in freezing weather (Michigan!).
It is an intake and an exhaust. One goes up and the other down. Those are not highly visible, just the billowing steam is a problem. The solution can't create backpressure or the furnace will shut off. It also can't be a haven for woodland creatures, or at least be easily cleaned out.