Typical Length of Glycol/Water Heat Tracing Jacket

[Jency]

Is anyone have a experience for designing an Glycol/Water heat Tracing Jacket system and know the typical length of the jacket could be?

I am in the processing of designing an glycol jacket heat tracing system to keep the sulfur line temperature above 138 degC. The sulfur line will be at least 600m long and will be expanded later to as long as 1500m more. I was told the typical length of the jacket is only 60ft. By spliting the total length, the number of the the tracing segment will be 30 more only for the first stage. And the other problem is the glycol/water flow rate in each segment will be really low and make the Re number inside of the jacket right between 2100 to 8000. I do searched some reference for get approved inside jacket heat transfer coefficent calculation. The answer was " inthis region, the heat-transfer coefficients cannot be predicted with certainty."

Is this kind of practice practical? Are there any similer practices had been done before? Is it possible to make each jacket segment longer from piping and construction point of view?

Thanks for any points.

 

[StoneCold]

Jency
If you are looking for a pipe temp minimum of 138C why not use steam for the heating medium? If you don't have steam use electrical heat tracing (if this is a big pipe that could be a problem). 60ft sounds about right if you are using 1/2" tracers. If you have bolt on jacketing or a double pipe setup then it will depend a lot on your glycol temperature and the flow rate of both the glycol and sulfer. You can probably get the bolt on jacketing people to give you a better idea if that is what you are going to do.

regards

StoneCold

 

[Jency]

Stonecold,

Thank you for your input.

Steam tracing is another consideration. Bolt-on Jacket will be used in this case. Sulfur flow rate is constant, my problem is finding out the right glycol flow rate to make the system working properly both in heat saving and system pressure drop.

I did talked with CSI people, from their point of view the tracing segmemt could be much longer even 200ft. The 60ft typical lenth is recommended by the sulfur expert.

 

[DavidG14]

I think the 60 ft is good. I'm not sure you want to operate glycol hot enought to keep sulfur molten.

If you need to jump over sections for flanges, valves, etc, the jump over pressure drops will be very high because the csa in the jump over is far less than the jacket.

Steam presents a problem with leakage. steam + sulfur = acid = corrosion.

I'd favor a heat transfer oil.

 

[TBP]

DavidD14 - Why would steam have a problem with leakage? Properly installed/maintained steam systems do not leak.