Hydraulic Tank Baffle Design

[natebott]

Looking for rules of thumb on baffle design for hydraulic tanks. Company standard, which has been around for years, states that oil passage cutouts have an area "at least 2-1/2 times the total pump inlet area." No one can tell me where this requirement came from. It seems like there would be a better way of determining the amount of open area. Possibly using the flow rate required.

 

[MikeHalloran]

Conjecturing one possible reason for the rule:

Chips and dirt arrive in the reservoir via the filler cap and the return lines. You want them to settle to the bottom and stay there. The last thing you need is a high velocity flow near the bottom of the tank that can keep that stuff in circulation.



Mike Halloran
Pembroke Pines, FL, USA

 

[sprintcar]

Not being a hydraulic expert by a long shot, I did a tank based on common sense and function. The pump was 8gpm and the tank size was a nominal 20 gallons. Since it was not on a stationary mount, the pump inlet (S) needed to be close to the center. The return (R) (thru a filter) was on one corner. The baffle ran the length of the v-bottom tank, slightly offset from the center. At the end opposite the return there were (2) 1.5" dia holes (H)located about 3" and 6" from the bottom. This way the aerated oil stayed toward the top, any particles that bypassed the filter stayed on the inlet side. The drain (D) was dead center in the V- bottom with a length of 1" npt pipe to provide a collector for any water or dirt in the system. It's been on test over 6 months with excellent results. Not the best graphic but:
--------------------------------
| <<<<<<O R
|
|
|(H)
|
|(H)
| O>>>>>>>>>>>>>> S
-----------------|D|-------------




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