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

2021 ◽  
pp. 004051752110417
Author(s):  
Qianqian Shi ◽  
Jiang Wang ◽  
Yuze Zhang ◽  
Qian Ding ◽  
Nicholus Tayari Akankwasa ◽  
...  
Keyword(s):  
Field Distribution ◽  
Air Pressure ◽  
Dynamics Simulation ◽  
Superior Performance ◽  
Rotor Spinning ◽  
Future Design ◽  
Yarn Properties ◽  
Spun Yarns ◽  
Airflow Field ◽  
Fancy Yarns

In order to explore the differences between conventional and dual-feed-opening rotor spinning units (RSUs), this work compares the airflow characteristics of two RSU models utilizing a computational fluid dynamics simulation model with the accuracy verified by airflow behavior observation and air pressure measurement. The effect of two different opening roller speeds on the airflow field distribution of a dual-feed-opening model is also investigated. In addition, the yarn properties of six pure and blended yarns corresponding to the two RSU models are evaluated. The results reveal that the distributions of airflow velocity vector and air pressure in the two RSU models show a strong similarity under the same boundary conditions. However, the dual-feed-opening model possesses a centrosymmetric and more balanced airflow field distribution compared to the conventional model. In addition, the dual-feed-opening yarns show a superior performance in comparison to the conventional yarns. Furthermore, for the dual-feed-opening model, there are equivalent contributions of two separated opening and fiber transmission systems to the airflow field distribution and yarn formation. Compared to the configuration with the same two opening roller speeds, the dual-feed-opening model configured with two different opening roller speeds obtains an improved blended yarn performance with having few effects on the airflow characteristics. This strength of the dual-feed-opening RSU could facilitate the production of blended and fancy yarns employing the fibers with diverse properties. This study could provide some guidelines for the manufacture of rotor-spun yarns and the future design of RSUs.

20—THE INFLUENCE OF THE AIR PRESSURE AT THE ROTOR-CLEANING DEVICE OF ROTOR-SPINNING MACHINES ON THE PROPERTIES OF COTTON OPEN-END-SPUN YARNS

1985 ◽  
Vol 76 (5) ◽  
pp. 301-313 ◽  
Author(s):  
A. Barella ◽  
A. M. Manich ◽  
L. Castro ◽  
Patricia N. Marino ◽  
J. Carpintero
Keyword(s):  
Air Pressure ◽  
Rotor Spinning ◽  
Spun Yarns ◽  
Cleaning Device

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

2020 ◽  
pp. 004051752095740
Author(s):  
Qianqian Shi ◽  
Nicholus Tayari Akankwasa ◽  
Yuze Zhang ◽  
Jiang Wang ◽  
Jun Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Approach ◽  
Operating Conditions ◽  
Air Pressure ◽  
Rotor Spinning ◽  
Model Unit ◽  
Transfer Channel ◽  
Rotor Wall ◽  
Airflow Field ◽  
Fundamental Research

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.

Effect of position of the fiber transport channel on fiber motion in the high-speed rotor

2021 ◽  
pp. 004051752110018
Author(s):  
Rui Hua Yang ◽  
Chuang He ◽  
Bo Pan ◽  
Hongxiu Zhong ◽  
Cundong Xu
Keyword(s):  
High Speed ◽  
Channel Model ◽  
Three Dimensional ◽  
Discrete Phase Model ◽  
Transport Channel ◽  
Rotor Spinning ◽  
Fiber Motion ◽  
Discrete Phase ◽  
Airflow Field ◽  
Fiber Transport

The task of the fiber transport channel (FTC) is to transport the fibers from the carding roller to the rotor. Its geometric position in the spinning machine has a strong influence on the characteristics of the airflow field and the trajectory of the fiber motion in both the rotor and the FTC. In this paper, a three-dimensional pumping rotor spinning channel model was established using ANSYS-ICEM-CFD software with three different positions of the FTC (positions a–c). Further, the simulations of air distribution were performed using Fluent software. In addition, the discrete phase model was used to fit the fiber motion trajectory in the rotor. The simulation results showed that among the three types of FTC, position b is the optimal condition. The gradients of airflow velocity in the channel at position b were greater than those of the other two positions, which is conducive to straightening of the fiber.

scholarly journals Influence of Airflow Field on Food Freezing and Energy Consumption in Cold Storage

2018 ◽  
Vol 53 ◽  
pp. 01038
Author(s):  
Guiqiang Wang ◽  
Xiaohang Cheng ◽  
Zhiqiangè Kang ◽  
Guohui Feng
Keyword(s):  
Energy Consumption ◽  
Field Distribution ◽  
Cold Storage ◽  
Food Products ◽  
Lumped Parameter Model ◽  
Freezing Process ◽  
Load Factor ◽  
Freezing Time ◽  
Food Freezing ◽  
Airflow Field

Currently most food products are cooled and frozen in air-blast cold storage to prolong storage time. The airflow field distribution in storage has a great impact on the process of food freezing and energy cost by that. In this paper, a transient model of food freezing considering airflow field was developed to simulation the temperature profile of air and food products during freezing process. A lumped parameter model was used to predict the temperature and moisture profile of air, which connected all other components together, such as air coolers, food products, envelop enclosure and refrigeration system. A finite difference method was employed to model the heat transfer inside food products during freezing, where the mass transfer was neglected as the food products were wrapped with polystyrene films. Unit load factor method was applied to calculate the sensible heat refrigeration capacity and thus the total capacity of air coolers. The simulation was conducted on a large cold storage filled with large quantities of packaged food products. Results show that there are great differences in airflow field distribution at different locations in cold storage, which lead to spacial differences in freezing time required. Inappropriate set point of freezing time prolongs freezing process unnecessarily and leads to extra energy consumption. Operational mode of air coolers has a great impact on the total energy consumption, as they consume energy themselves and release equivalent heat into storage simultaneously.

scholarly journals Open-End Yarn Properties Prediction Using HVI Fibre Properties and Process Parameters

2017 ◽  
Vol 17 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Hanen Ghanmi ◽  
Adel Ghith ◽  
Tarek Benameur
Keyword(s):  
Response Surface ◽  
Process Parameters ◽  
Processing Parameters ◽  
Raw Material ◽  
Spun Yarn ◽  
Yarn Properties ◽  
Spun Yarns ◽  
Yarn Count ◽  
Input Variables ◽  
Rotor Spun Yarn

AbstractThis article provides three models to predict rotor spun yarn characteristics which are breaking strength, breaking elongation and unevenness. These models used noncorrelated raw material characteristics and some processing parameters. For this purpose, five different cotton blends were processed into rotor spun yarns having different metric numbers (Nm10, Nm15, Nm18, Nm22, Nm30 and Nm37). Each count was spun at different twist levels. Response surface method was used to estimate yarn quality characteristics and to study variable effects on these characteristics. In this study, predicting models are given by the analysis of response surface after many iterations in which nonsignificant terms are excluded for more accuracy and precision. It was shown that yarn count, twist and sliver properties had considerable effects on the open-end rotor spun yarn properties. This study can help industrial application since it allows a quality management-prediction based on input variables such as fibre characteristics and process parameters.

scholarly journals Improving inter-organizational care-cure designs: specialization versus integration

2018 ◽  
Vol 26 (4) ◽  
pp. 328-341
Author(s):  
Angele Pieters ◽  
Kim E. van Oorschot ◽  
Henk A. Akkermans ◽  
Sally C. Brailsford
Keyword(s):  
Clinical Research ◽  
Integrated Care ◽  
Organizational Design ◽  
Perinatal Care ◽  
Dynamics Simulation ◽  
Superior Performance ◽  
Archival Data ◽  
Content Type ◽  
Risk Patients ◽  
Low Performance

PurposeThe purpose of this paper is to investigate inter-organizational designs for care–cure conditions in which low-risk patients are cared for in specialized care organizations and high-risk patients are cared for in specialized cure organizations. Performance impacts of increasing levels of integration between these organizations are analyzed.Design/methodology/approachMixed methods were used in Dutch perinatal care: analysis of archival data, clinical research and system dynamics simulation modeling.FindingsInter-organizational design has an effect on inter-organizational dynamics such as collaboration and trust, and also on the operational aspects such as patient flows through the system. Solutions are found in integrating care and cure organizations. However, not all levels of integrated designs perform better than a design based on organizational separation of care and cure.Practical implicationsA clear split between midwifery practices (care) and obstetric departments (cure) will not work since all pregnant women need both care and cure. Having midwifery practices only works well when there are high levels of collaboration and trust with obstetric departments in hospitals. Integrated care designs are likely to exhibit superior performance. However, these designs will have an adverse effect on organizations that are not part of this integration, since integrating only a subset of organizations will feed distrust, low collaboration and hence low performance.Originality/valueThe originality of this research is derived from its multi-method approach. Archival data and clinical research revealed the dynamic relations between organizations. The caveat of some integrated care models was found through simulation.

Reducing Yarn Hairiness in a Modified Ring Spinning Yarn Path by Various Offsets

2011 ◽  
Vol 331 ◽  
pp. 493-497
Author(s):  
Xu Zhong Su ◽  
Wei Dong Gao ◽  
Ting Ting Wu ◽  
Xin Jin Liu ◽  
Yun Zhang
Keyword(s):  
Critical Region ◽  
Breaking Force ◽  
Ring Spinning ◽  
Fiber Tension ◽  
Yarn Properties ◽  
Spun Yarns ◽  
Spinning Process ◽  
Spinning Triangle ◽  
Yarn Hairiness ◽  
The Right

Spinning triangle is a critical region in the spinning process of yarn. Its geometry influences the distribution of fiber tension in the spinning triangle and the properties of spun yarns, such as the yarn breakage and hairiness. In this paper, the relationships between the spinning angle and yarn properties especially the yarn hairiness were investigated under various horizontal offsets. The properties of spun yarns produced by the modified system were evaluated and analyzed. Both left diagonal and right diagonal yarn arrangements were examined. The results indicate that the right diagonal yarn path leads to reduce yarn hairiness but the left diagonal yarn path leads to increase yarn hairiness; the breaking force of yarn changes little; yarn evenness deteriorates slightly with the changes of offset.

A Study on Airflow Field of Super-High Speed Pectination Grinding Wheel Based on PIV

2008 ◽  
Vol 389-390 ◽  
pp. 332-337 ◽  
Author(s):  
Ya Dong Gong ◽  
Yan Cheng Zhang ◽  
Hu Li ◽  
Wan Shan Wang
Keyword(s):  
Data Processing ◽  
Data Acquisition ◽  
Field Distribution ◽  
High Speed ◽  
Grinding Wheel ◽  
Experiment Research ◽  
Theory Analysis ◽  
General Rules ◽  
High Speed Grinding ◽  
Airflow Field

Adopting the method of PIV, systematical theory analysis and experiment research were made on the airflow field distribution of super-high speed pectination grinding wheel, as well as experiment design and data acquisition, the data processing was carried out through the software of FlowMap, Tecplot, and Matlab. By analysis and discussion focused on experiment results, the general rules of airflow field distribution in super-high speed pectination grinding wheel were preliminary drawn, which provides the research foundation with a view to find a new method for the effective supply of super-high speed grinding coolant.

scholarly journals Numerical investigation of airborne infection in naturally ventilated hospital wards with central-corridor type

2016 ◽  
Vol 27 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Qi Zhou ◽  
Hua Qian ◽  
Li Liu
Keyword(s):  
General Hospital ◽  
Natural Ventilation ◽  
Index Patient ◽  
Dynamics Simulation ◽  
World Health ◽  
Future Design ◽  
Airborne Infection ◽  
Ventilation Rates ◽  
Hospital Wards ◽  
The Impact

Natural ventilation is believed to control airborne infection due to high ventilation rates while an undesired flow pattern may cause infection transmission in hospital wards. A computational fluid dynamics simulation was carried out in this study to investigate the impact of airflow pattern on cross infection in a real central-corridor hospital ward with natural ventilation in Nanjing, China. The simulation results demonstrate that the predicted infection risks of the downstream cubicle are up to 10.48% and 11.59% as the index patient is located in the corridor and in the opposite upstream cubicle, respectively. Under this circumstance, the downstream cubicle should be listed on the high-risk list and the central-corridor type is not recommended in a naturally ventilated ward. Measures such as keeping cubicle doors closed should be taken in order to cut off the transmission route. The results not only give direct evidence to strongly support World Health Organization’s recommendation but also suggest required amendment of the Chinese standard GB 51039-2014 to improve ventilation arrangement in general hospital wards in China. Our findings are useful for improving the future design of general hospital wards for airborne infection control.

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