Restriction Orifice Sizing

[ushakuna]

hi...

I am sizing a restriction orifice for following application:
Compressed Air is taken from Process Air Compressor's 2nd stage to another process from 8.8 kg/cm2g to 0.2 kg/cm2g at a rate of 850 Nm3/hr.

For this purpose, restriction orifice is to be provided in the compressed air line to reduce pressure from 8.8 kg/cm2g to 0.2 kg/cm2g and to restrict flow at 850 Nm3/hr (around 1100 kg/hr).

I have calculated the orifice size as per Formula given in Chemical Process Safety, Fundamentals with Applications, Crowl & Louvar, Page No. 133 for Choked Flow of gas through hole. I am getting 16mm orifice hole when upstream Pr = 8.8 kg/cm2g, Temp = 40°C, Mol wt for air = 29, Cp/Cv = 1.4, Co = 0.72.

If any further information is required please let me know.

Can anybody confirm whether the calculated orifice dia is correct?

Shakuna

[shankarmathur]

Hi
Does anyone have a spreadsheet for Sonic Nozzle calculations according to ASME / ISO ?
Thanks in advance for your co operation.

Shankar Mathur

[shankarmathur]

Hi
Does anyone have a spreadsheet for Sonic Nozzle calculations according to ASME / ISO ?
Thanks in advance for your co operation.

Shankar Mathur