High pressure homogenization is widely used to produce small droplets in liquid products.The use of two homogenization units(e.g.orifices) in series there by is generally accepted as increasing homogenization efficiency,even when the mechanism is still not fully understood yet.It is shown that for a single stage orifice operate data given overhead pressure,the drop size decreases with increasing
back pressure first until a minimum is reached and then increases due to the lower total pressure drop
due to the lower flow velocity and driving force.Simultaneously observation showed that backpressure suppresses cavitation.