3 replies to this topic

[ramnathsharma]

Dear friends,

We have installed a thermic fluid heater with the following details.

Pump Flowrate : 30 M3/Hr
Coil pipe dia : 40 mm
Coil outer dia : 700 mm
No of turns: 36
Density of oil: 1200 kg/m3
Pipe material of construction : Mild Steel Sch 40

We want to calculate the pressure drop across the coil, we have used darcy-weishbach equation but not satisfied with the results.

Can anyone suggest anyother equation to calculate the pressure drop across the coil.

Thanks & Regards

Ramnathsharma

[JoeWong]

Please see if you can find some information in Kern Heat Transfer book...

[ankur2061]

Dear Ramnath,

Check out this weblink. It gives equations and also a calculator for tube pressure drop for fired heaters. You can do a preliminary check and compare it with your earlier results. You can also ask your fired heater vendor to provide you the pressure drop information.

http://www.heaterdesign.com/wintherm/

Hope this helps.

Regards,
Ankur.

[DRS]

You have to use D-W equation for pressure drop calculation except that friction factor should be calculated as mentioned in Perry's 6-18 and 6-19. The flowrate seems to be quite high for a 40NB pipe. Are you sure about the above data?