Pressure drop in half pipe coils

[StoneCold]

I am looking for some articles or equations to calculate the pressure drop in half pipe coils that make up a reactor jacket.

Thanks

 

[Latexman]

I've had good success using the equation in Crane TP410 for more than one bend. You have to calculate two diameters. One from 4 x hydraulic radius to use for the Reynolds Number and the other for equivalent flow area of a round pipe for use for the velocity terms. I may have more input on this tomorrow when I'm in my office.

Good luck,
Latexman

 

[Latexman]

In my Crane TP410 (25th printing in 1991) the derivation of their "Resistance of Bends" equation starts on page 2-12 and is presented in final form in Equation 2-20:

K_B = (n-1)(0.25.f_T.Pi.(r/d) + 0.5.K₁) + K₁

n = number of 90^o bends
f_T = fully turbulent Darcy friction factor
r = radius of bend
d = diameter of pipe (I use 4 x R_H for 1/2 pipe)
K₁ = K of 1 bend from Table on page A-29

r/d K₁
1 20.f_T
1.5 14.f_T
2 12.f_T
3 12.f_T
4 14.f_T
6 17.f_T
8 8.f_T
10 10.f_T
12 12.f_T
14 14.f_T
16 16.f_T
20 20.f_T

When I put K_B into a pressure drop equation I use d = equivalent flow area diameter, square root of (4.A/Pi), so the velocity is correct.

It has been field tested many, many times by me over the years.

Good luck,
Latexman

 

[StoneCold]

Thanks
I will give it a test against the method suggested by 25362 and let you know how they compare.

Thanks