Cooling down of atm HCl from -60°C to -30°C

[peter Hond]

Dear
I would like to calculate how much meters of pipeline it takes to cool down HCl from -60°C to -30 °C in a pipeline using only air flow around it.
The flow of HCl through the pipeline is 30000 kg/u.
I took 3 m/s of wind at 20 °C.
The pipeline is made of uninsulated stainless steel and is 4'' in diameter with a thickness of 1,4 mm.

Thanks it advance!

 

[peter Hond]

The medium in the pipeline is at atmospheric conditions 1,013 bara.

 

[pierreick]

Hi,
To support your calculation, consider the paper attached. You can easily develop a spreadsheet using the relations included in the document.
I've some doubt about the quantity you want to heat in a 4" pipe. Is it 30 tons/hour?
Pierre

 

[peter Hond]

Thanks a lot. This file will certainly help!

 

[MortenA]

@peter, if this is a real world problem then you have more things to consider than basic heat transfer as provided by Pierreick (very nice though). The air will have water and at -60ºC surface temperature you are going to see a massive ice cape form around the pipe. This ice will insulate the pipe and thus reduce the heat transfer. Thinking back to my heat transfer classes in uni i think i remember that there is a way to approximate the ice thickness and then the insulating effect.

--- Best regards, Morten Andersen