6 replies to this topic

[kholish2000]

We have 30357 kg/h of Natural Gas in pipe at  6 kg/cm2g and flowing density 4.89 kg/cm3. Using 14" pipes, we find that actual gas velocity 64.86 ft/s and sonic velocity 23.02 ft/s (based on K=1.33).Excel spreedsheet calculation attached. Are my calculation correct? How much this condition affect to noise and vibration ? thanks for your advise.

Edited by kholish2000, 03 February 2018 - 11:38 PM.

[breizh]

hi ,

No attachment , I believe there is a typo on the density unit !

In case I've attached a paper to support your work.

Breizh

Edited by breizh, 05 February 2018 - 04:54 AM.

[SIVAMOORTHY]

Please upload your excel sheet calculations

[kholish2000]

I'm sorry, i upload my excel calculation but i forgot to press the "attached this file" button. it was not appeared at my quotes. Here is my claculation. Thank you for your prompt response

Attached Files

•  question.xlsx   76.87KB   30 downloads

[breizh]

Hi ,

temperature R seems wrong and make sure when you use  pressure for your calculation  , it will be absolute pressure .

The mach Number is weird , huge , For sure error in the calculation of sound velocity , too low !

 

Better to chose one system , either metric (SI) or Imperial .

 

Breizh

Edited by breizh, 05 February 2018 - 04:55 AM.

[kholish2000]

Dear Mr. Breizh,

 

Based on your suggestion, i check my calculation, and I realized that I used wrong Temperature Unit Reamur (^oR) vs absolute Temperature Rankine ®. It gives very big different result in Sonic Velocity Calculation, so the final result gives 2.82 Mach (Before) vs 0.35 Mach (After). It's seem very realistic result.

 

Thank you for all member's support.

Attached Files

•  question rev.xlsx   76.99KB   29 downloads

[breizh]

Hi ,

 Please review the calculation of sound velocity :

Vs =( K*R*T/M) ^.5  

with K=cp/Cv ; R =*8.314  (SI ) , M = molecular weight of the gas ( Kg /mol) , T (K )

 

Good luck .

Breizh

Edited by breizh, 05 February 2018 - 08:09 AM.