5 replies to this topic

[kybele39]

Hello All,

Happy New Year!

My client wants to use 75mm calcium silicate insulation for a offshore water bath heater shell insulation. I used mineral wool at 2" thickness. My cold face temperature is 85F after 2" thick mineral wool usage. I thought calcium silicate can be used at higher temperatures then 250F.

Should I use 3" Calciumsilicate or increase the mineral wool for an offshore platform heater in Thailand?

Thanks for your answers,

Kybele

[Erwin APRIANDI]

Dear kybele,

can you elaborate more, on what is the purpose of the insulation application
what type od fluid do we handle, and environmental condition and etc

I don't think not much of people can help if you forget those detail

[kybele39]

This is an insulation for water bath heater shell at an LNG terminal.

It is not an harsh environment. You may think because of ocean a heater may be against the atmospheric corrosion.

I always use mineral wool for this type of insulation jacketing with aluminium. I am thinking Calcium silicate is more expensive alternative than the mineral wool. May be an overkill for insulation purpose.

Hope this can help to answer all to my topic. I just want some input in comparison of the both material for industrial applications. Specially in a gas plant.

Thanks

Kybele

[Erwin APRIANDI]

Dear Kybele,

Happy New Year to you too

As what I know, the k value for calcium silicate will be higher than the k value for mineral wool
the k value of calcium silicate will be at around 0.06 (W/mK)at 25 degree C, while for mineral wool the k value will be at 0.04 (W/mK)at same temperature (taken from engineeringtoolbox). means mineral wool will be a better insulation at the same thickness.

I'm not sure about the price of both material as I never purchased one, and for the area that you mentioned (Thailand) I don't think that it is a harsh area, so no need for special material to handle the environmental condition there. And from my previous project, mostly I used on glasswool or mineral wool, also for application of insulation on offshore platfrom in Indonesia which having quite the same condition as Thailand.

Hope it help

Edited by erwin.apriandi, 17 January 2011 - 04:24 AM.

[Zauberberg]

Kybele,

For evaluating different types of insulation, there is a freeware software provided by the North American Insulation Manufacturers Association (NAIMA), available for download at:

http://www.pipeinsul...4/download.html

Some of the software features are:

* Determines economic thickness of insulation based on return on investment for chosen fuel cost, installed cost, tax rates, maintenance, etc.
* Calculates the amount of insulation needed for personnel protection for various design conditions.
* Calculates the thickness of insulation needed for condensation control.
* Calculates greenhouse gas emissions and reductions.
* Determines surface temperature and heat loss/gain calculations of individual insulation thickness up to 10 inches (250 mm).
* Solves for outside insulated surface temperatures for all types of insulation applications at different process temperatures and various configurations.
* Calculates bare vs. insulated heat loss efficiency percentages for horizontal and vertical piping, ducts and flat surfaces.
* Performs calculations for various flat surfaces, selected pipe sizes and all standard iron pipe sizes from 1/2" to 48" (15 - 1200 mm).
* Calculates heat loss/gain and outside insulated surface temperatures for any insulation material provided the thermal conductivity, associated mean temperatures, and temperature limit are entered by the user.

Not sure what is your/client's target when considering different types of insulation - perhaps it is driven by their own, internal standards, and/or based on field experience with both types you are evaluating. This is certainly something you can discuss with the client.

[bernath]

Kybele,

You can check the range temperature in GPSA (storage tank chapter, perhaps? I don't quite remember it) or TEMA.

Actually, there's one good article regarding insulation here in the cheresources.

http://www.cheresour...ulationzz.shtml

you can develop your own spread sheet to perform the comparison. All the thermal conductivity can be obtained from GPSA (insulation) and TEMA (for metals). It should not take long time.

As pointed by erwin, mineral wool will be a better insulator with the same thickness. You may want to add the thickness if you decide to switch the insulation with calcium silicate in order to achieve the same face temperature.

perform the calculation (if you have the time) or use the freeware mentioned above by Zauberberg to get the exact thickness.

regards,
bernath