Effect of Orifice Shape and Dip Tube Clearance on the Discharge Hydrodynamics and Residual Heel Volume in a Dispensing Bottle

Abstract

In this work, the roles of the orifice shape and off-bottom clearance of the dip tube on the discharge flow rate of a complex fluid from a dispensing bottle and on the resulting residual “heel” volume left in the bottle were investigated. Particle Image Velocimetry (PIV) was used to monitor the discharge rate and the heel. The dip tube clearance and the orifice shape both affected the formation of the heel. Dip tubes provided with a flat cut orifice not only resulted in a smaller heel compared to angled cut orifices but also generated a higher flow rate at constant suction pressure. Reducing the dip tube clearance produced smaller heel volumes irrespective of the shape of the dip tube orifice. The results of this work were validated using the velocity contour maps obtained by PIV and, separately, with the heel profiles obtained from the PIV raw images.