Vaporization of Methanol
Vaporization of Methanol
(OP)
Hi,
I am trying to do a calculation to find how much length of pipe is needed to completely vaporize methanol from room temperature to ~110 F.
The flow rate of methanol is 5.27E-5 kg/s
Methanol's heat of vaporization is 1100 kJ/kg
So... Qevap = (mass flow) * (heat of vap) = 5.27E-5 * 1100 kJ/kg ~ 58 W
The pipe supplying the methanol will be coming from a 1/16" diameter stainless pipe at room temperature and into an oil bath at 110 F (43 C).
I keep coming up with very high answers for the length of pipe I need (~ 18 m)
Am I doing something wrong? Can someone help me out?
Thanks,
Mike
I am trying to do a calculation to find how much length of pipe is needed to completely vaporize methanol from room temperature to ~110 F.
The flow rate of methanol is 5.27E-5 kg/s
Methanol's heat of vaporization is 1100 kJ/kg
So... Qevap = (mass flow) * (heat of vap) = 5.27E-5 * 1100 kJ/kg ~ 58 W
The pipe supplying the methanol will be coming from a 1/16" diameter stainless pipe at room temperature and into an oil bath at 110 F (43 C).
I keep coming up with very high answers for the length of pipe I need (~ 18 m)
Am I doing something wrong? Can someone help me out?
Thanks,
Mike
-Mike





RE: Vaporization of Methanol
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Vaporization of Methanol
Best regards
Morten
RE: Vaporization of Methanol
RE: Vaporization of Methanol
Apart from the above queries and remarks, I noted that:
• BP of methanol at atmospheric pressure is 64.5oC.
• Enthalpy change from liquid at 25oC to vapor at normal BP is 1208 kJ/kg.
RE: Vaporization of Methanol
-Mike
RE: Vaporization of Methanol
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Vaporization of Methanol
I think I have to use an equation with the log mean temperature difference, but I used...
Q = K A (T2-T1)
58 W = (25 W/m^2) * (Pi * d * L) * (110-25)
I solved for L.
-Mike
RE: Vaporization of Methanol
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Vaporization of Methanol
Recheck your figures. Although I disagree with the values used, and if I didn't err, your figures result in a length of about 5.5 m.