Particle-Laden Tubeless Siphon

A tubeless siphon was created by sucking a 1% aqueous Polyoxfn1 solution laden with particles from a beaker into a cylinder by moving a piston. The piston speed and particle concentration were varied. At very high rates of withdrawal, all the liquid could be removed before the siphon broke. In this case, the beaker was completely cleaned without a trace of liquid. The addition of small concentrations of small, nearly neutrally buoyant particles greatly enhanced the pulling power of the liquid, reducing the threshold speed of withdrawal at which the beaker was completely cleaned. At speeds of withdrawal smaller than the threshold not all of the fluid-particle mixture is pulled out of the beaker. The amount pulled out first increases, then decreases as the particle concentration is increased.