4 replies to this topic

[KHANFA]

HI All,

I am trying to calculate propylene losses from a double wall storage tank operating at 0.066 kg/cm2g & -42 Celsius.

 

In the tank calculation sheet its shown that percent losses per day are 0.1548%, this number is derived considering the design liquid level ( maximum level) i.e. 80%.

 

My question is the loss of propylene is dependent on liquid level in the tank, higher the liquid level higher the losses & vice versa?

 

 

[Pilesar]

The heat transfer rate between the liquid and the wall will be higher than the heat transfer rate between the vapor and the wall.

[KHANFA]

Thanks Pilesar for your feedback, so you mean the losses will be more if we keep the tank at higher levels?

[Pilesar]

As the tank level is higher, more metal is contacted. You can think of it as a percentage of liquid lost each day. With a double wall tank and regular usage, the losses may not be significant, but you would not expect long term storage at atmospheric pressure without using refrigeration. See this thread for additional comments which may be useful: https://www.cheresou...age-conditions/

[Bobby Strain]

Is this tank with its auxiliaries already in operation? Or being constructed? You title the query "ethylene". You then say propylene is stored. Is the loss calculation for ethylene or propylene?

 

Bobby

Edited by Bobby Strain, 08 August 2023 - 06:01 PM.