pressure or vacuum
pressure or vacuum
(OP)
Problem:
Transfer 10k gallons of contents from one tank to another tank in 20min.
With contents velocity not exceeding 10ft/s
Assumptions: (Tanks and piping)
Both source and destination tanks have 11’ dia and 15’ straight side with ASME dish top/bottom heads rated at 75 psig / full vacuum. And are at the same elevation 20’ apart under 0 psig
A 6” sch 10 pipe from the bottom center outlet of one tank to bottom center of the other connects the tanks. The length of the 6” pipe is 20’
Assumptions: (Contents)
1500Cp
1.1 Sg
Contains 5% free Vinylidene Chloride
Contents is shear sensitive and cannot be pumped in the conventional sense. It will have to pushed or pulled or a combination of each
By opening the valve on the 6” bottom connecting line, gravity will push 1/2 the contents to the empty tank.
The vapor space in the destination that the content displaces is returned to the source tank via return line connecting the two tanks at the top.
I need recommendations as to what method to use to transfer the remaining contents.
Transfer 10k gallons of contents from one tank to another tank in 20min.
With contents velocity not exceeding 10ft/s
Assumptions: (Tanks and piping)
Both source and destination tanks have 11’ dia and 15’ straight side with ASME dish top/bottom heads rated at 75 psig / full vacuum. And are at the same elevation 20’ apart under 0 psig
A 6” sch 10 pipe from the bottom center outlet of one tank to bottom center of the other connects the tanks. The length of the 6” pipe is 20’
Assumptions: (Contents)
1500Cp
1.1 Sg
Contains 5% free Vinylidene Chloride
Contents is shear sensitive and cannot be pumped in the conventional sense. It will have to pushed or pulled or a combination of each
By opening the valve on the 6” bottom connecting line, gravity will push 1/2 the contents to the empty tank.
The vapor space in the destination that the content displaces is returned to the source tank via return line connecting the two tanks at the top.
I need recommendations as to what method to use to transfer the remaining contents.





RE: pressure or vacuum
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
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RE: pressure or vacuum
I apologize if I was unclear
I cannot use a pump of any kind. I'm constrained to applying pressure or inducing a differential pressure
RE: pressure or vacuum
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: pressure or vacuum
Sorry no, maybe its my foggy brain. Is the product destroyed or adversely altered when pumped? I don't understand why it can't be pumped. Just curious.
And you can't pressurize the first tank either?
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com
RE: pressure or vacuum
This material is essentially polymer globule in water it cannot be “pumped” until it is fully reacted and stabilized.
Sure, I can pressurize the source tank but a some point I'll have to relieve the pressure in that tank - that's the problem.
I don't want to have to vent off VC laden vapor
I thought maybe steam would work since it would just condense to water ...
Or a vacuum pump-- creating a vacuum in the destination vessel, discharging into the source vessel
RE: pressure or vacuum
If you can't pump, and pressure (from steam or otherwise) is a problem, then you really only have gravity left, no?
BigInch,
Yes, a bit tongue in cheek, but not much.
If you need 7 feet in the second tank, then you need 14 feet in the first tank to equalise. Once the contents is used, you repeat the process. Why won't this work?
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: pressure or vacuum
The entire contents of the source vessel must be transferred to the destination vessel
This is a batch process
RE: pressure or vacuum
RE: pressure or vacuum
Going the Big Inch!![[worm] worm](https://www.tipmaster.com/images/worm.gif)
http://virtualpipeline.spaces.msn.com
RE: pressure or vacuum
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
The harder I work, the luckier I seem
RE: pressure or vacuum
Bud Trinkel CFPE
HYDRA-PNEU CONSULTING, INC.
fluidpower1 @ hotmail.com
http://www.fluidpower1.us
RE: pressure or vacuum
RE: pressure or vacuum
Have you considered peristaltic pumps or Tesla-type pumps ?
RE: pressure or vacuum
Sorry. I just read the OP again and yes, you did say full vacuum.
15' of SG 1.1 is about what, 50 psi? Sorry, don't have anything but esitmates in my head.
At full vacuum, you still only have 14.7 psi, so I don't think creating a vacuum in the second tank will work.
A blow case will still require a gas of some sort, and you still have to deal with getting rid of the gas unless it can go down stream with the process fluid - and it seems that this is not desireable.
I still think that gravity is your best cheapest solution - if you can live with a heel in the first tank.
You mentioned that this is a batch operation - I still don't understand why you can't half the batch size?
Oh, one other question. How are you filling up the first tank? And why can't you do the same to the second tank?
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: pressure or vacuum
Then, there is still the old and reliable Archimedes screw to lift the liquid suspension to the full tank height to maintain gravity flow from the highest point.
RE: pressure or vacuum
RE: pressure or vacuum
This would probably not be as energy efficient as the screw lift, but it would have the advantage of not requiring any mods to the vessels.
Harvey
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: pressure or vacuum
Looking at screwli9ft systems and steam air ejector that discharges to source vessel.
RE: pressure or vacuum
RE: pressure or vacuum
I’m asking this with respect to the amount of space under vacuum and the amount of space under pressure at the end of the transfer
RE: pressure or vacuum
RE: pressure or vacuum
Are you talking about pressurizing one tank with vapor from the opposite one?
RE: pressure or vacuum
To mizzoueng,
What happens to the siphon when the level in the receiving tank is higher than in the delivering tank ?
RE: pressure or vacuum
RE: pressure or vacuum
What Katmar suggests is the same method I've used to move 8,000 lbs of R-22 liquid refrigerant from the 4000 ton evaporators to the refrigerant receiver at the Denver International Airport central Chiller Plant. I don't know how these vapors react or what thier boiling/flash temps. are but if they are reasonably low the procees is very effective.
With the R-22 refrigerant, we hook the suction of our transfer compressor to the top of the empty tank, and the discharge of the compressor to the top of the liquid tank. The charge of the liquid can be move in about 45 min. to 1 hour. After the liquid has been transfered we switch connections and draw vapors from the remainder of the liquid tank and discharge them through a condenser to the transfer tank. R-22 has a low boiling point so this is'nt too hard. I don't know the particulars of your liquid.
I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int./JCI
RE: pressure or vacuum
I'm not a real engineer, but I play one on T.V.
A.J. Gest, York Int./JCI