Characterization of the airflow field in the rotor spinning unit based on a novel experimental approach and numerical simulation

Abstract

It is very challenging to experimentally characterize and verify the airflow in the rotor spinning machine because the process takes place in an enclosure. In an attempt to portray the process, we present a methodology that combines a novel experimental approach and numerical techniques. We developed a model unit and used colored smoke to mimic the airflow behavior practically, measured the air pressure, and compared the results to the simulation data. Three state conditions, namely suction and rotation (the regular rotor spinning operation, (Case 1)), without rotation (Case 2), and without suction (Case 3), were adopted to investigate the formation mechanism of the airflow field in the rotor spinning unit based on two operating conditions. Results show that, in a regular state, the airstream accelerates rapidly in the transfer channel under the dominant action of air suction at the rotor outlet and crashes clockwise to the rotor wall with the joint action of two operating conditions. In the rotor, the airflow flows clockwise with the velocity distribution of a multi-ring gradient due to the dominant action of high-speed rotor rotation. Analytics from the air pressure indicate that while the air pressure in the rotor is mainly controlled by the action of the air suction mechanism, it is also affected by the superposition action of the rotation mechanism. This approach is groundbreaking for rotor spinning machine optimization and is anticipated to trigger more insights that will lead to fundamental research in the spinning industry and beyond.

Comparison of the airflow characteristics and yarn properties between conventional and dual-feed-opening rotor spinning units

“…Since it is difficult to cover the opening roller part in the experimental rotor spinning apparatus, the opening roller part was ignored in the two developed RSUs. As in previous research, 24 each developed RSU consists of a rotor, a lid, and a spinning chamber (see Figure 4). In addition, all of them are transparent to make it easy to observe the rotor interior, as shown in Figures 4(c) and (d).…”

A novel air-assisted rotor spinning technique for ultra-stable antibacterial nanofiber/cotton hybrid yarn

“…CFD applies numerical simulation analysis and algorithms to calculate and visually present fluid flow, which has been employed to demonstrate the effect of spinning parameters and rotor component configuration on the overall qualities of rotor-spun yarns. 31–34…”

“…CFD applies numerical simulation analysis and algorithms to calculate and visually present fluid flow, which has been employed to demonstrate the effect of spinning parameters and rotor component configuration on the overall qualities of rotor-spun yarns. [31][32][33][34] Three-dimensional physical models for the airflow field. For the conventional rotor (CR) spinning, a suction device pushes external airflow into the internal rotor from the yarn guiding mouth and the transfer channel, respectively.…”

Progress of air flow field and fiber motion analysis in textile manufacturing process: a review

“…Among them, the velocity distribution, pressure distribution, and streamline trajectory are the basic features of the flow field distribution, Qiu et al 8 confirmed the basic characteristics of flow field distribution through the analysis of two-dimensional (2D) and three-dimensional (3D) flow fields, which validated the spinning mechanism of the rotor. Shi et al 21 obtained the velocity and pressure distribution in the rotor through simulation, and explored the influence of extraction and rotation mechanisms on the flow field. It is concluded that the air extraction provides the necessary negative pressure conditions for fiber transportation, and the rotating mechanism facilitates fiber alignment and transfer to the sliding surface and accumulation groove.…”