Fluid Engineering increases the efficiency of Cotton cleaning equipment

Initial conditions and goals

The figure shows a successful particle excretion.

Raw cotton is used as a base material and spun into yarn.

The supplied cotton contains various foreign substances, which negatively impact the quality of the finished product. For this reason, the cotton undergoes various cleaning levels at the beginning of the spinning process, in which the system provided by Jossi Systems AG is used as the final level. In this facility, uncleaned cotton tufts are fed through a transport duct using airflows. Inside this duct, a variety of sensors detects contaminants in the cotton and ejects them using compressed air impulses. Although it was possible to detect almost all types of foreign matter, not all contaminants were ejected. The goal of this project was the ejection of all foreign matter detected by the system.

The figure shows the snapshot of a building up transient jet as measured by PIV (Particle Image Velocimetry).

In this figure, the building nozzle jet is shown as the result of a flow simulation (CFD). — A jet conveys foreign matter, which flows with the cotton in the vertical channel right from bottom to top, in the right-angled arranged suction on the left. The top figure shows a successful particle excretion. The middle figure shows the snapshot of a building up transient jet as measured by PIV (Particle Image Velocimetry). In the figure below the nozzle jet is shown as a result of a flow simulation (CFD).

Implementation and results

In the first half of the project, the airflow conditions in the ejection module were investigated both experimentally, as well as through numeric airflow simulations. These results led to redesigning several components of the ejection module, which were developed, produced, and tested. The flow optimisation resulted in a significant improvement of the ejection rate compared to the existing module.