how to calculate steam flow

Forum about flow calculators available on pipeflowcalculations.com and how to find solution for your fluid flow problem.
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steamcar
Posts: 1
Joined: Fri Dec 16, 2011 12:16 am

how to calculate steam flow

Post by steamcar »

I see the pipe flow calculator states that it is for incompressible Newtonian liquid so I presume it cannot be used to work out steam flow. I have an interest in a steam generator where water is pumped through a heated pipe coil and hopefully emerges still as water but at saturation temperature for the pressure (600psi at 250 deg C). Situations will arise where steam is produced so I wish to know how this will effect the back pressure. The tables of properties do include steam but I'd like to know if these can just be entered as the properties of water are entered and the calculator run in the usual way. Doing this indicates a huge increase in back pressure which may be the case but it would be helpful to have an expert view on this. I should add that it is a recirculating generator in which the heat is applied to a coil in a pumped circuit which includes a steam drum. Although the operating system pressure is 600psi the circulating pump is within the pressure system and only needs to pump with sufficient head to send water through the coil. This is of the order of 10psi as long as the coil is mainly filled with water - what interests me is, if too much heat is applied so that say half the length of the coil contains a significant proportion of steam within the brew what does this do to the pressure the pump needs to apply at the start of the coil to maintain 600 psi at the return to the steam drum?
Thanks
expressfire
Posts: 7
Joined: Wed Feb 08, 2012 3:13 am

Re: how to calculate steam flow

Post by expressfire »

The pressure drop in saturated steam distribution pipes can be calculated in metric units as

dp = 0.6753 106 q2 l (1 + 91.4/d) / ρ d5

where

dp = pressure drop (Pa)

q = steam flow rate (kg/h)

l = length of pipe (m)

d = pipe inside diameter (mm)

ρ = steam density (kg/m3)
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