Calculator
Coating dispersion vessel and impeller sizing calculator
Vessel volume, diameter and impeller size for the dispersion quantity you are making.
Result
- Liquid volume
- 9.8 L
- Minimum vessel
- 12.3 LIncludes 25% freeboard
- Vessel diameter
- 250 mmAt a height to diameter ratio of 1
- Liquid height
- 200 mm
- Impeller diameter
- 83 mmOne third of vessel diameter
- Impeller clearance
- 67 mmOff the base, one third of liquid height
Formula
vessel volume = liquid volume × (1 + freeboard ÷ 100) D = ∛(4V ÷ π) at H/D = 1 impeller ≈ D ÷ 3, clearance ≈ liquid height ÷ 3
Why this number matters
A dispersion mixed in the wrong vessel never disperses properly. Too wide and the impeller cannot move the whole volume, so pigment settles at the wall. Too narrow and you draw a vortex that pulls air in, which reads as spitting at the gun and spray marks on the tablet. The one third rules for impeller size and clearance are the standard starting geometry.
Where it goes wrong
Freeboard is not optional. A ready-mix powder entrains air as it wets out and the level rises before it falls, so a vessel filled to the brim will foam over on the first minute of mixing.
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