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Cardigan9

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Poles Formula (see page 10 of attachment)

www.mech.hku.hk/bse/MEBS6000/mebs6000_1011_04_steam.pdf

Where have I gone wrong?

• q = flow (m3/h)

• d = diameter of pipe (mm)

• h = pressure drop (mbar)

• l = length of pipe (m)

• s = specific gravity of gas (density of gas / density of air)

h = ( q^2 * s * l ) / ( 0.0071^2 * d^5 )

q = 6 m3/h

d = 20mm

l = 19M

s = 0.58

The result is 2.459 i.e. the pressure drops by 2.2459 mb, which on the face of it looks fine, the problem is that if I reduce the flow rate the loss of pressure over the length of the pipe drops. Which in theory means that if I start with 21mb gas pressure and have a lower flow rate I end up with a higher pressure at the end of the pipe; that can't be right can it?

www.mech.hku.hk/bse/MEBS6000/mebs6000_1011_04_steam.pdf

Where have I gone wrong?

• q = flow (m3/h)

• d = diameter of pipe (mm)

• h = pressure drop (mbar)

• l = length of pipe (m)

• s = specific gravity of gas (density of gas / density of air)

h = ( q^2 * s * l ) / ( 0.0071^2 * d^5 )

q = 6 m3/h

d = 20mm

l = 19M

s = 0.58

The result is 2.459 i.e. the pressure drops by 2.2459 mb, which on the face of it looks fine, the problem is that if I reduce the flow rate the loss of pressure over the length of the pipe drops. Which in theory means that if I start with 21mb gas pressure and have a lower flow rate I end up with a higher pressure at the end of the pipe; that can't be right can it?

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