2 replies to this topic

[Abhijeet Shete]

Height of liquid in a horizontal cylinder

Hi
I am Trying to size the Flare Knockout drum by using API521 guidelines.
for that to calculate drop out time I required vertical space for vapour flow (Hv).I am trying to calculate first the height of liquid in a cylinder so that I can calculate hight of vapour space.

I know the dimensions of a cylinder and cross sectional area for liquid in cylinder

I know how to calculate the volume for a given height, but i cant flip the equation to get the height.

volume = area * length;
area = r2(θ - Sin[θ])/2, where θ = 2ArcCos[(r-h)/r]

So that goes that

area = volume/length.

How can i isolate the height from the area calculation? I don't think it's possible because it relies on trig and calculating the dimensions of a triangle based on the height of liquid and the radius of the cylinder.

If it is not possible to isolate that height, is it possible to work it out another way without iterating over every possible height until i come to the actual volume specified.

Regards
Shete

[Andree]

I do not know an answer to your question, but I can advise you a "seek goal" command in excel - what it does is actually iteration, so that you can easily find "h" when you know "V" using your formula for "V" :-)

[demank]

Hello,

You can use my excel file that I attached, then take a seek goal like andree said.

Attached Files

•  Horizontal_Cylinder.xls   361.5KB   200 downloads