K ? of best insulator 1

[nong]

In oil pipeline we use mineral wool ( K=0.038 ) as an insulator but it doesn't work well. I 'ld like to know that are there any insulators that better than this wool.

 

[Goorah]

I'm not sure if you are referring to to k = 0.038 in SI or english units. I'm talking in english units. Perhaps you are too, since in my HX book, I see "loose rock wool" with k = 0.039 Btu/hr-ft-F. I don't know how practical these would be for a pipeline; but I also see "Silica Aeroget" at 0.014, Kapok at 0.020, hair felt at 0.021, 1.5 lb/ft3 glass wool at 0.022.

You should also search on the internet for "insulation"

 

[Gianfranco]

Nong,

Please, could you specify why the insulation doesn't work well. In other words: from which point of view the rockwool are not satisfactory?

- heat dissipated or flowed from the pipeline

- temperature of the outside surfaces (for safety or evnvironmental aspects)

- mechanical stability of the insulations (maintenability)

- life span

- acquiring cost

- destructions

- environmental problems

- ???

BTW: I personally "hate" the mineral and rook wool, but the question is too generic. Please, let's know something more.

Gianfranco

 

[MortenA]

Maybe you should used preinsulated pipe in pipe. Check

http://www.logstor.com

they manuf. and sell this type of pipes. The insulation material is polyuretheane (PUR)it has a heat transfer coef of 0.017 BTU/hr-ft-F (0.03 W/m-C)

Best regards Morten

 

[EdCollinson]

Check also itp-interpipe.fr they also supply pipe in pipe systems but use IZOFLEX microporous silica insulation rather than PU.

Regards

Ed

 

[butelja]

While not typically used on oil piping, vacuum insulated pipe will have an even lower k value. It is used mainly in cryogenic service.

 

[nong]

Insulated pipe in pipe doesn't work well for very long pipeline containinng crue oil ie. 62 km (results from Pipesim) which the outlet temp is lower than required. We are investigating other options.
Thank you for all of your opinion.
Nong

 

[MortenA]

Hi Nong

The U that i quote for pre insulated PIP using PUR is about as low as it gets using conventional technology (i'm not considering vacuum insulated pipes to be conventional for pipelines due to assumed high installation costs). As you can see its about half the value that you have quoted for mineral wool (and much easier to install).

What are your operating conditions?

Best Regards

Morten

 

[Jerre]

Consider Reflective wrap which is extremely efficient for pipe insullation. Insulators retards the heat flow they do not dissapate it well. This mean that the heat will eventially bring the temperature of the insullator to that of the pipe or reverse depending which is hotter. Aluminum maybe a better choice.

 

[bgregg]

Microporous Insulation is about twice as efficient as Mineral Wool especially at temperatures above 500F. It can be produced as flexible sheets or molded pipe sections. It is also considerably more expensive than Mineral Wool. One of the lower cost producers is Thermodyne in Elkhart, IN. (

http://www.thermodyne1.com).

I used to work with the owner. They can do a thermal calculation for you using a version of ASTM C-680. Ask for Pat Heller (owner) or Jack Magruder (Sales).

Bill

 

[MortenA]

Ir does not seem very likely that an oil pipeline should reach temperature higher than say 150 deg F. So microporou insulation is haldly what Nong is looking for either.

Best Regards

Morten

 

[bgregg]

I'm not that familiar with oil pipelines and didn't know the typical process temperatures. I am used to mineral wool being used at higher temperatures. Fiberglass should be a little more efficient at the lower temperatures versus mineral wool due to the smaller fiber diameters. It might be less costly as well. Johns-Manville and Owens Corning both offer mechanical pipe insulations using fiberglass. Bill

 

Per bgreegg's comments, Microporous Insulation may be al alternative to some of the applications which are being discussed. I am the Market Manager for the Min-K Division of Thermal Ceramics where we manufacture this material and do various value-added steps to put it into a usable form. We did some analysis on piping for the petroleum industry a couple of years ago calculating (mathematically) the increase in temperature of fluids in a pipe based on flow-rate, distance, external temperature and initial fluid temperature. The objective was to maintain the temperature of the fluid (oil) at a high enough level to avoid any solidification. If you would like information on our product line, let me know.

Thanks,

Ken
kvannimwegen@thermalceramics.com