I Need Help Choosing a Accumulator For A Hot Oil System
I Need Help Choosing a Accumulator For A Hot Oil System
(OP)
Hi all,
I need help choosing a accumulator or something else appropriate for my task.
I have a pumping system with approximately 5 gallons of oil in it. It is a closed system. When I run the machine the temperature goes up (200°C system max) and as the temp increases so does the pressure due to thermal expansion of the oil. Currently I have to bleed off fluid to stay within the pressure rating of the system and this is undesirable for what we are trying to do (we are a research lab).
I would like to be able to maintain the system pressure from 0-100 psi.
Be able to run the system up to 200°C.
Flow rate of the system is 10-30 gpm.
I was looking at a piston type accumulator as when we heat the oil in the system the volatiles in the oil boil off and I want to prevent this by having no headspace while still allowing room for expansion.
Most piston type accumulators are rated to several thousand psi which I don't need and are rather expensive.
Do you guys have any suggestions for accumulator or other options??
Thank you!
I need help choosing a accumulator or something else appropriate for my task.
I have a pumping system with approximately 5 gallons of oil in it. It is a closed system. When I run the machine the temperature goes up (200°C system max) and as the temp increases so does the pressure due to thermal expansion of the oil. Currently I have to bleed off fluid to stay within the pressure rating of the system and this is undesirable for what we are trying to do (we are a research lab).
I would like to be able to maintain the system pressure from 0-100 psi.
Be able to run the system up to 200°C.
Flow rate of the system is 10-30 gpm.
I was looking at a piston type accumulator as when we heat the oil in the system the volatiles in the oil boil off and I want to prevent this by having no headspace while still allowing room for expansion.
Most piston type accumulators are rated to several thousand psi which I don't need and are rather expensive.
Do you guys have any suggestions for accumulator or other options??
Thank you!





RE: I Need Help Choosing a Accumulator For A Hot Oil System
SceneryDriver
RE: I Need Help Choosing a Accumulator For A Hot Oil System
It matters as the viscosity changes if I lose volatiles and the system is very sensitive to a increase in viscosity. Putting a chiller on the accumulator would help by causing the volatiles to condense, but then I need to ensure that they enter back into the flow.
RE: I Need Help Choosing a Accumulator For A Hot Oil System
We understand that the flow rate induced by a centrifugal pump in a circulating system will be influenced by the viscosity of the fluid.
Suppose you ran the system open/vented for a while, and let the volatiles boil off, and then foreverafter ran closed with the now thickened oil; could that work?
If not, maybe you need a gear pump or other PD pump.
Mike Halloran
Pembroke Pines, FL, USA
RE: I Need Help Choosing a Accumulator For A Hot Oil System
Ted
RE: I Need Help Choosing a Accumulator For A Hot Oil System
the oil, for seal compatibility
the temperature range of the oil, for seal compatibility
the maximum volume change of the oil
the maximum pressure for the part of the system you will store oil from
the as-mentioned desire to have no free oil surface.
the type of fittings you are using in the rest of the system if you want commonality or the fitting you've chosen for making the connection
any size restrictions
any desired mounting provisions
Once gathered together, you will have enough information to work with a hydraulics component supplier.
The system flow rate probably doesn't matter. Since it is temperature related, a piston will be OK. You may need to insulate the accumulator if the oil properties vary enough to be noticeable; also because the accumulator may extend beyond the equipment and you want to avoid burns from skin contact. You might also plumb a line to the accumulator to allow more flexibility in locating the accumulator.
RE: I Need Help Choosing a Accumulator For A Hot Oil System
An accumulator is an energy storage device for holding high pressure fluid. If that is, in fact, what you require, then you have to have an additional expansion tank to deal with fluid expansion in your loop.
RE: I Need Help Choosing a Accumulator For A Hot Oil System
I guess you could say that it is a oil heat application (sorry, I have to be vague). I would love to just use a expansion tank, but I can't have the head space where volatiles can boil off and get trapped (I think the volatiles would still boil off in a nitrogen atmosphere?). For what I need, an accumulator is overkill. I just found what I really need, a volume/thermal expansion compensator, but I don't know any good sources. As stated before the system is relatively low pressure (100 psi) and I am not trying to store energy, just to account for a volume change while maintaining the system pressure (within 0-100psi) while the temperature changes. Some of the ones I saw are stainless steel bellows which sounds like a good option as it would allow the higher temps I am looking for. Any thoughts?
RE: I Need Help Choosing a Accumulator For A Hot Oil System
You are making your problem much more difficult than it really is. Dowtherm and Syltherm have very detailed handbooks on how to design oil heating systems.
If you keep your expansion tank at room temp., then volatiles become a trivial problem and you lessen heat losses.