how to design steam nozzle

[seeni]

pls help me to design steam nozzle

i want conv.& div. typ
prop of steam in inlet side is 6 bar, 200 deg.
requirement in outlet side is 0.6 bar and 60 deg

how to calculate the throat area
if water spary is there, how to calculate the mass of water
and size of water spray nozzle

 

[poetix99]

You have not specified your conditions very carefully. At the risk of being pedantic (you can look it up), I ask the following:

Pressure is "absolute" or "gauge"? It is the difference between pressure ratio of roughly 10 or 4.4, which makes a very big difference in the expansion ratio.

The exhaust pressure is the only thing that you need to specify for the discharge. The isenthalpic expansion through the nozzle will determine the discharge temperature. (Perhaps you have specified the temperature of the discahrge plenum, but it really doesn't matter.)

The isentropic determination of an expansion ratio is available in texts on compressible fluid flow, or even from any first level undergraduate text on thermodynamics.

You may make a "reasonable" estimate of the nozzle efficiency (between 0.98 and 0.95 for a well-made nozzle with a good surface finish) and adjust the "perfect" equations for the estimated nozzle efficiency.