Steam consumption calculations- compounds

[dhic001]

I'm never any good at doing calculations, or wokring the theories, so i'm wondering if someone can do me a calculation or two. Basically I'm wondering about the steam consumption of two different sizes of compounds, just for curiousitys sake. Both engines running on 120psi, 1) 4.5 + 9 * 5.5 inch running at 400rpm max 2) 8 + 16 * 8 inch running at 250rpm. Am curious to see how much steam they use. Both engines are marine engines running into a vacuum.

Thanks to anyone who can do the maths.

Daniel

[fredrosse]

Crude numbers, easily +/- 20%, so many variables undefined.

4.5 + 9 * 5.5 inch running at 400rpm 28 HP, 550 PPH Steam

8 + 16 * 8 inch running at 250rpm 65 HP, 1100 PPH Steam

[dhic001]

Thanks Fred, those rough fiqures are fine. just the sort of indication I wanted.

Thanks,
Daniel