Flow between two tanks
Flow between two tanks
(OP)
I have one verticle tank and one horizontal tank that are connected together in an "L"-shape. There is a hole between the two tanks that will allow oil to move from the horizontal tank to the verticle tank and vice versa. I need to size this hole in order that the oil in the horizontal tank does not exceed a certain level as it heats up and expands, instead, when the oil heats up and expands, it will reach a certain level, thereafter, it will move into the verticle tank. The knowns I have are the density of the oil at various temperatures, the volume of the verticle tank, the volume of the horizontal tank. I planned on making a guess on the hole size, then I was going to calculate the delta P, then based on that, calculate what head is required for that solved delta P. I am very confused if this is the right strategy or not, and if so, exactly how to do it. Any help would be appreciated. Thanks!





RE: Flow between two tanks
Locating the hole, might.
Locate the hole vertically such that its top is at or a little below the level you want to maintain. Then as the oil in the horizontal tank rises, air will be trapped above the oil as soon as it occludes the hole, and any further expansion will cause flow into the vertical tank. The level in the horizontal tank will rise a little as the air is compressed by the pressure represented by the gravity head of the difference in levels between the tanks.
This doesn't work if the top of the horizontal tank is vented in any way.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: Flow between two tanks
RE: Flow between two tanks
Locating the hole is rather easy. You know the initial volume of oil and the height of liquid column in the tank. You get the final volume of the oil at the increased temperature from the density data and calculate the new liquid column height. If you want to size the hole, check the time rate of volume increase from one height to another height and this is the flowrate you require to pass through the hole.
But this seems to be a redundant exercise unless you explain the system in detail.
Regards,
RE: Flow between two tanks
I know the volume of V-Tank.
I know the volume of H-Tank.
I know the density of the oil.
As the oil the heats up, the volume increaes. As this happens, I cannot have the oil in H-Tank go above the solid line. It must evacuate into the V-Tank. If the level in the V-Tank continues to rise, there is a vent at the top that will drain it back into the H-tank. I need to size the hole so the oil flow behaves in this manner. Does this help?
V-Tank
_____
| |
| |
| Spill Over
| ---->
| |
| |
| | ___________ Oil not allowed above line
| | |
| Hole |
| <---- <---- |
| | | H-Tank
|_____|____________|
RE: Flow between two tanks
I know the volume of V-Tank.
I know the volume of H-Tank.
I know the density of the oil.
As the oil the heats up, the volume increaes. As this happens, I cannot have the oil in H-Tank go above the solid line. It must evacuate into the V-Tank. If the level in the V-Tank continues to rise, there is a vent at the top that will drain it back into the H-tank. I need to size the hole so the oil flow behaves in this manner. Does this help?
V-Tank
_____
| |
| |
| Spill Over
| ---->
| |
| |
| | __________ Oil not allowed above line
| | |
| Hole |
| <---- <---- |
| | | H-Tank
|____|___________|
RE: Flow between two tanks
The height of spill over line in the vertical tank should not be above the oil not allowed line on the horizontal tank. This is irrespective of whether the tanks are pressurized or not, in a gross sense.
Regards,
RE: Flow between two tanks
RE: Flow between two tanks
http:/
What do you think??
Thanks!
RE: Flow between two tanks
The link you provided doesn't talk about your specific issue. The head difference is the difference in heights between the maximum possible oil height and the bottom of the hole, if the oil level in the vertical tank is not above the bottom of the hole. Otherwise, you have to consider the height of oil level in the vertical tank instead of hole bottom height.
These two links will be of some help to you.
http://www
Thread378-116505
Regards,
RE: Flow between two tanks
If there is no "check valve" function in your "hole" (the lower one where oil is supposed to flow from horz. vessel (rightmost) to vert. vessel (leftmost)) - then the level in the two vessels will always be the same (the level in the one of the tank may be slightly higher in order to "create head for flow").
If you do have a check valve - then the oil could NOT flow back (left to right) - but it would on the other hand never get above the max level experienced in the rightmost vessel. How could it? What would "drive it"?
Best regards
Morten