density and temperature relationship

[psozot]

what is the relationship exist between density and temperature of HSFO? is it dependent on storage tank size or not? are density and temp. varies in 1:1 ratio necessarily. plz also tell other sites that have info on this

 

[TD2K]

HSFO? High sulfur fuel oil? The temperature versus temperature is not affected by the size of your storage tank.

Assuming that is what you are talking about, I'd use the API oil density versus temperature chart (GPSA Engineering data books have a copy of this in them, I expect many other references do also).

The change in specific gravity with temperature is linear up to a certain temperature, that's likely close to 500F for fuel oil (as the fluid's specific gravity decreases, the plot of specific gravity versus temperature begins to deviate from linear at a lower temperature).

 

[psozot]

we have storage tanks with capacity of 32000 MT. 150 ft dia and 15m height for HSFO. daily we take temp. and density but on numerous occasions we do not find linear relationship b/w temp & density. for example some observed figures are:

temp density
40 .945
40.5 .945
41. .9455

does this have any relation to the size of tank and head of product in tanks.?

 

[TD2K]

If HSFO is high sulfur fuel oil, then the changes in density you are seeing are likely due to changes in composition.

Fuel oil is usually a mixture of various heavy streams and cutters blended together to meet several specifications (commonly min/max density, min/max viscosity, max sulfur, con carbon, etc). Depending what streams and their flow rates that are being used, the final product is not a 'pure' component like butane. It will vary in its properties.

It does not have any relation to the size or head pressure in the tank. Liquids do have some variation in density with pressure but you need very large pressure changes to see this, much more than what you are talking about here for head pressures.