This calculator gives rigid-body rim speed and centripetal acceleration for an entered basket diameter and rotational speed. It does not rate a hydro-extractor, predict extraction performance or determine safe RPM.
Hydro-extractor Interactive Calculator
Explore ideal circular-motion kinematics at the basket wall.
Equation Used
- Constant angular speed and circular wall radius equal to half the entered diameter.
- Point evaluation at the nominal basket wall with g0=9.80665 m/s².
- Rigid-body kinematics only; no transient spin-up/down or imbalance.
- No basket/material stress, perforations, contents distribution, retained water, bearing/shaft/motor, critical speed, vibration, guarding, containment, extraction efficiency or safety model.
Wall G is the calculated centripetal acceleration divided by standard gravity. It is a dimensionless ratio, not a load capacity or permitted operating speed.
Ideal basket-wall circular motion
At radius r and angular speed omega, wall speed is omega r and inward centripetal acceleration is omega²r. Dividing by standard gravity gives a dimensionless G ratio.
The animation is a qualitative rotation cue and does not model liquid or textiles.
Use as a kinematics check
The identities can verify rim speed and acceleration for a stated diameter and RPM. They cannot establish safe rotational speed, separation performance or machine capacity.
Continuous acceleration ratio
Convert rotational speed from rpm to angular speed using ω = 2πN/60. Rim speed is v = ωr and centripetal acceleration is a = ω²r; dividing a by standard gravity gives the acceleration ratio.
For one kilogram at the wall, ideal radial force magnitude F=ma is numerically a newtons, hence the N/kg tile equals acceleration.
Worked rim-speed example
For D=900 mm and N=700 rpm, radius is 0.45 m, rim speed is about 32.99 m/s, wall acceleration is about 2,418.1 m/s² and the acceleration ratio is about 246.58 G.
Scope and limitations
Real rotating equipment requires basket and perforation stress/fatigue, corrosion and wear, contents mass/distribution and liquid loads, shaft and bearing loads, motor/drive torque and braking, imbalance and vibration, critical speeds and foundation, lid interlocks, containment/guarding, overspeed protection, inspection and manufacturer-rated operating limits.
Questions
Is the G ratio a safe operating limit?
No. It is only kinematics.
Does higher G predict dryness?
No. Permeability, loading, time, liquid properties and drainage are absent.
Why does N/kg equal m/s²?
Because one newton is one kg·m/s².
Calculation basis
The nominal wall radius is half the entered diameter. At constant angular speed, rim speed is ωr and inward centripetal acceleration is ω²r. Standard gravity is 9.80665 m/s².
Force per unit mass equals acceleration, so its numerical value in N/kg matches the acceleration in m/s². These equations describe motion at the wall; they do not determine basket strength, extraction performance or an allowable rotational speed.
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