2 replies to this topic

[CHEMeng88]

Hi,

I am doing a study to insulate external floating roof tank to reduce heat loss to surroundings. May I know if it is possible to insulate the roof of the external floating roof? I cannot seem to find any examples where it has been done so. Typically, only fixed roofs are insulated.

Thanks for your help in advance.

[ankur2061]

CHEMeng88,

Normally the roof of any atmospheric or low pressure storage tank irrespective of whether it is fixed roof or floating roof is never insulated.

The reason is quite simple. The surface area of the roof in comparison to the cylindriical surface area is very small. Also, for fixed roof tanks the roof is in contact only with vapors and the thermal conductivity of vapors which may be a mixture of process vapor and air or process vapor and inert gas is relatively poor compared to liquid which is in contact with the walls of the cylindrical portion of the tank.

Personally I have never encountered any non-refrigerated tank with insulation provided to it's roof.

Regards,
Ankur.

[kkala]

I have not found floating roof tanks with insulated roof, either, even though their roof contacts the stored liquid. My interpretation was that the floating roof makes the insulation itself, since it has to be light enough to float.
Nevertheless a little search indicates several floating roof types:
Double deck (pontoon), microballoons, that could support the interpretation.
Single deck, where the roof contacts liquid only peripherally; so most of roof area contacts vapors, offering some insulation.
Panlike roofs, not offering insulation, to my understanding.
(Perry, 4th ed, 1963, 6-66, storage and bulk transport of fluids, etc).
Matter is getting challenging, help from experts would be welcomed. Probably panlike roofs are rarely made now.