Effect of Jet Nozzle Position on Mixing Time in Large Tanks

The present investigation focuses on the impact of jet nozzle orientation on mixing time in a cylindrical tank. The aim is to identify nozzle positions that improve mixing performance and to elucidate the governing parameters that influence it. A water tank was employed for the experiment. The vertical inclination angle (& alpha;) and the horizontal inclination angle (& beta;) of the jet nozzle determined the nozzle positions. Mixing time was determined using an inert tracer and spectrophotometry measurements. The findings show that the mixing time is significantly influenced by the position of the jet nozzle position. The accuracy of existing jet turbulence and the circulation models for the prediction of mixing time was evaluated for the different nozzle positions. Our results indicate that both models provide accurate predictions for the conventional centrally aligned (& beta; = 0 & DEG;), upward-pointing jet nozzle positions only (& alpha; > 0). For the other nozzle positions where & beta; > 0 & DEG; and at varying & alpha;, the data follow the same trends as the jet turbulence and circulation models; however, the proportionality constants vary. Shorter mixing times can be attributed principally to longer jet path lengths and therefore higher fluid entrainment and circulation as well as higher dissipation rates per jet length squared. However, it is suspected that the three-dimensional nature of the flow pattern generated in the tank also plays a non-negligible role since mixing is hindered when the nozzle points more towards the tank wall.

Automated summary

This investigation explores the influence of jet nozzle orientation on mixing time in a cylindrical tank. It aims to find nozzle positions that enhance mixing performance and understand the relevant parameters. The study uses a water tank and measures mixing time through an inert tracer and spectrophotometry. The findings demonstrate that jet nozzle position significantly affects mixing time. It evaluates the accuracy of existing jet turbulence and circulation models for predicting mixing time at different nozzle positions. Results show that the models accurately predict mixing time for centrally aligned and upward-pointing jet nozzle positions, but with varying proportionality constants for other nozzle positions.