# Heat loss of a steel steam pipe

1. Oct 27, 2009

### Batman318

I have a heat transfer question, I work in a plant and am doing a re-insulation project. If an unexposed steel steam pipe (k=47) of diameter 10 inches, maintains an internal temperature of 460F and is exposed to ambient air (70F) flowing at 5 mph across the pipe. Determine the heat loss per unit length. The inside diameter of the pipe is 9.224 inches and the O.D. is 10.75 inches. Emissivity can be taken as 0.8. σ = 5.6669 x 10^-8.

I know you need to find (q/L)rad and (q/L)convection but I'm having trouble figuring out h, the convection coefficient. can anyone help?

2. Oct 27, 2009

### Q_Goest

3. Oct 27, 2009

### Staff: Mentor

For working in a plant and doing a project, that sure sounds like the wording of a schoolwork question...

4. Oct 27, 2009

### Batman318

haha wish it was. Finally figured it out, after reading my heat transfer book from a few years ago (thank you very much ), you just have to find the reynolds number and use that to find the Nusselt's number which gives you h.

5. Oct 28, 2009

### Staff: Mentor

Glad you figured it out. Q_Goest is the guy to thank in this case.