Testing and Analysis of the Speed of Water Jet in Water Jet Looms

In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main effective approaches to increase the filling insertion rate and to widen the reed space of the loom are pointed out.

Treatment of Textile Industrial Wastewater from Water Jet Loom Machine

The objective of this research was to investigate the optimum condition for treatment of textile industrial wastewater from water jet loom machine by chemical coagulation and electrocoagulation methods. The variables of chemical coagulation method were type and amount of chemicals, pH and stirring rate. For electrocoagulation method, the variables were electrode materials, electric potential and contact time. It was found that the optimum condition of chemical coagulation method was 10% （w/w） of aqueous solution of aluminum sulphate 80 mL and 0.01% （w/w） of aqueous solution of coagulant aids, cationic polymer 32 mL per 4 L of wastewater at oH 8. The mixture solution was rapidly stirred with 120 rpm for 1 min and then slowly stirred with 20 rpm for 20 rain. The removal efficiency of turbidity, COD and oil content were 88.88%, 85.20% and 77.72%, respectively. For electrocoagulation method, the optimum condition was using aluminum electrode with 35 V and 150 min of contact time. The removal efficiency of turbidity, COD and oil content were 98.86%, 91.63% and 89.84%, respectively. It can be concluded from this study that the textile industrial wastewater treatment from water jet loom machine with electrocoagulation method is more efficient than that with chemical coagulation method.

Dynamics of Water Jet in Water Jet Looms

On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be improved to raise the speed of water jet as well as weft insertion rate and to enlarge the width of woven fabrics a lot. At the same time it also points out that to increase water jet speed and to prolong its affective jet time depend mainly on the accretion of spring rate (constant)of stiffness and the diminution of plunger's cross sectional area respectively.

The kinematic Design of Beating-up Mechanism for Water-jet Loom Series Modified from Air-jet Loom

For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.

A Study of the Gas Flow through Air Jet Loom

Air jet loom, as one of the shuttleless looms, transports a yam into warps using viscosity and kinetic energy of an air jet. Performance of this picking system depends on the ability of instantaneous inhalation/exhaust, configuration of nozzle, operation characteristics of a check valve, etc. In the recent past, many studies have been reported on the air jet discharged from a nozzle exit, but studies for understanding the flow field characteristics associated with shear layer and shock wave/boundary layer interaction in the nozzle were not conducted enough. In this paper, a computational study was performed to explain the flow field in the air jet nozzle with an acceleration tube and validated with previous experimental data available. The results obtained from the computational study show that, in the supersonic flow regime, the flow field depends significantly on the length of acceleration tube. As nozzle pressure ratio increases, drag force acting on the string also increases. For a longer acceleration tube, the total pressure loss is large, owing to the frictional loss.

DYNAMIC PROBLEMS OF WATER JET FOR WEFT INSERTION

In recent years, China has imported thousands of water jet looms. In order to master thetechniques and to develop the variety of products, the dynamic problems of this jet device hasbeen discussed in this paper briefly. It contains 1. Introducing the rotary plunger pumps and the open-type jet nozzles. 2. Establishing the fundamental equations of the dynamic analysis for water jet device. 3. An illustrating example to show the jet speed, and the rate and time duration for the jetflow varies with different pipe resistance, cross section area of the nozzle outlet, and the springcompressive deflection etc. It is useful for research and production references.

Review and Prospect of the Shuttleless Loom Development

In this paper, a review of the shuttleless looms’ development shows that three types of shuttleless looms: rapier, Jet and gripper projectile, are now equally matchable with each other. A prospect of the shuttleless loom’s development is also dealt with. It can be predicted that both rapier and Jet looms will be developed further and the future development of a new type of modern weaving looms will be prosperous in the coming 21st century.

从ITMA ASIA+CITME 2022看织造机械的技术进步

总结2022中国国际纺织机械展览会暨ITMA亚洲展览会上织造机械及织造准备的最新技术进展。织造机械的结构与性能不断优化,发展更加贴近市场需求。国产剑杆、喷气、喷水织机的制造水平发展迅速,提高了国产设备的核心竞争力。随着人工智能的爆发式增长,织造机械的数字化转型步伐加快,先进的信息技术和自动化工具的运用使织造机械呈现出个性化、智能化、绿色化发展新趋势。认为:近几年织造机械在高速化、自动化、绿色化方面进步显著。

喷水引纬机构动态特性对自由射流的影响

为适应不同喷水引纬织机幅宽的需求,基于伯努利与液体连续性原理建立喷水引纬机构动力学模型,喷嘴自由射流初始段最大距离与纬纱所受射流牵引力的数值模型,分析其动态特性并通过弹簧刚度系数确定凸轮系统最低转速,探讨不同弹簧刚度系数与弹簧最大压缩量条件下机构动态特性对柱塞运动周期、射流最大速度、雷诺数、射流初始段最大距离、纬纱所受射流牵引力的影响;仿真结果表明:弹簧刚度系数增大时,柱塞运动周期变小,对应的凸轮系统最低转速变大,当弹簧最大压缩量取0.029 m,弹簧刚度系数取40 000、50 000、60 000 N/m时,水射流速度最大值为62.19、69.85、78.99 m/s,射流初始段最大距离为937、1 000、1 074 mm,纬纱所受水射流牵引力为5.37、6.44、7.28 N;而弹簧最大压缩量对上述变量的影响幅度很小,故在大幅宽织机需求下应首要考虑使用更大刚度系数的弹簧。

纤维束与异形筘内合成气流的相互耦合作用

为提高喷气织机辅助喷嘴的引纬效率,设计了3类多孔阵列式辅助喷嘴,揭示了多孔形状与阵列方式对合成气流速度分布和弹性纤维束运动位移的影响规律。建立了纤维束-气流耦合的动力学模型,基于任意拉格朗日-欧拉法数值模拟了三维瞬态流场分布及纤维束运动位移,并采用高速摄像机拍摄纤维束运动位移,验证了数值模拟结果的正确性。通过数值模拟得到了异形筘道内合成气流速度分布、速度梯度及纤维束头端运动位移。结果表明:异形筘道内合成气流速度梯度变化与纤维束头端位移具有相关性,合成气流速度梯度越小,纤维束运动位移也越小;三圆孔中心阵列辅助喷嘴形成的合成气流速度梯度最小,纤维束运动位移最小,适合用于弹力较大织物的引纬。

小提花织物双织轴织造工艺的优化

探讨在双织轴喷气织机上生产平纹小提花织物的技术措施。以一款细号高密平纹小提花织物生产为例,统计织造工序停台次数并进行原因分析。通过优化浆料配方,改进浆纱工艺,提高了经纱质量。在织造工序,重点优化了经位置线、开口时间、上机张力、织机速度等工艺参数,提高了织机效率。结果表明:工艺优化后,织机效率从69.8%提升到88.9%,百米布疵点评分从17分降低到14分。认为:优化后的工艺参数符合生产要求,并提高了双织轴喷气织机生产平纹小提花织物的织机效率。

基于流-固耦合辅助喷嘴特性分析

文章主要研究喷气织机中不同孔型的辅助喷嘴应力形变问题,利用Fluent软件建立了辅助喷嘴结构的三维模型,采用k-ε湍流模型对其结构进行流-固耦合数值模拟,对单圆孔、椭圆阵列以及圆阵列三种孔型的辅助喷嘴在同一流体激励下进行分析,得到各个辅助喷嘴在同一流体激励下的变形情况,结果表明,椭圆阵列在流体激励下的形变最大,圆形阵列辅助喷嘴结构的形变最小,为喷气织机的辅助喷嘴结构设计生产提供参考建议。

喷气织机织造中的火灾预防

为避免喷气织机在织造过程中发生火灾,降低火灾隐患,介绍织造车间火灾预防的重要性,从人的不安全行为和物的不安全状态2方面分析织造过程中可能出现的火灾危险源;详细分析喷气织机制动装置、绞边装置、主动力电机、松经装置、电气控制箱内部等火灾隐患部位和排查重点,结合生产实际制定喷气织机预防火灾检查表,说明织造时预防火灾的要求及扑灭注意事项。指出:及时清理棉花飞絮、花毛和飞花等,制定检查表,并据此对喷气织机易发热部位进行检查维护,做好散热,合理设置皮带张紧力,定期给轴承、齿轮加油,可有效预防织造中的起火问题。

基于CFD的喷气织机辅助喷嘴流场分析

为研究辅助喷嘴的流场性质,建立喷气织机辅助喷嘴流场的三维模型,利用计算流体动力学(CFD)分析软件Fluent对辅助喷嘴流场的三维模型进行数值模拟,得到供气压力为0.28 MPa条件下辅助喷嘴出口实际流速中心线上的速度分布曲线、压力分布曲线以及不同供气压力条件下辅助喷嘴出口的速度分布曲线。计算结果表明:供气压力为0.28 MPa时,辅助喷嘴出口最大风速达404 m/s,在辅助喷嘴出口出现了负压区;随着供气压力的增大,辅助喷嘴出口风速逐渐增大,供气压力每增加0.10 MPa,出口风速约增加50 m/s。通过与相关文献实验值的比较,证明了数值模拟方法和实验方法分析辅助喷嘴流场的一致性。

喷气织机辅助喷嘴流场特性分析与纬纱牵引实验研究

针对喷气织机辅助喷嘴引纬工艺的关键问题,利用CFD软件Fluent对辅助喷嘴引纬流场进行数值模拟,得到辅助喷嘴出口射流中心线上的速度曲线。为验证数值模拟的合理性,通过实验获取了不同供气压力条件下多种辅助喷嘴出口气流中心线上不同位置的速度值,并将实验数据与数值模拟进行比较。结果表明,实验所得速度值的总体变化趋势与数值模拟得到的速度曲线基本一致。在一定程度上,很好地验证了运用Fluent软件对辅助喷嘴引纬流场进行数值模拟的可行性。文中进一步以2种辅助喷嘴为研究对象对不同种类纬纱的牵引作用进行实验测试,证实了单孔辅助喷嘴引纬流场具有射流强度大、稳定性高、集束性好等特性。

喷气织机引纬筘槽内气流状态的测试分析

为了解辅助喷嘴的喷射区间长度、辅助喷嘴的喷向角、辅助喷嘴的供气压力等因素与引纬筘槽内气流流速的关系,采用毕托管,通过自行设计的测量装置对引纬筘槽内的气流速度进行测量,同时研究了不同供气条件下气流速度的变化情况。研究结果表明:引纬槽内的气流速度变化剧烈,并按辅助喷嘴间距周期性波动;供气压力过小时筘槽内气流速度无法达到引纬要求;在引纬槽的同一截面上,不同的测量点具有不同的速度,纬纱在不同测量点受到的作用力也不一样。

基于CAN总线喷气织机控制系统的研制

针对高速喷气织机对电气控制系统通讯实时性、可靠性的要求,设计一种基于CAN总线的喷气织机控制系统。控制系统采用模块化设计思想,由主控制器模块、电子送经/卷取模块、人机界面模块和一些传感器组成。各功能模块采用带CAN通讯接口的芯片,使得各功能模块成为CAN网络上的一个节点。通过CAN网络与其他模块进行数据交换,实现快速、可靠的控制。经运行调试证明,该控制系统能达到高速喷气织机的控制要求,运行稳定,具有较好的可维护性。

喷气织机辅助喷嘴喷孔结构优化设计

为寻求喷气织机辅助喷嘴的最优结构以改善辅助喷嘴引纬的综合性能,建立辅助喷嘴的三维模型,利用CFD软件的Fluent对辅助喷嘴引纬流场进行数值模拟,得到0.3 MPa供气压力下辅助喷嘴出口射流中心线的速度曲线、辅助喷嘴入口的质量流,以及距离辅助喷嘴出口40 mm处截面上的速度分布。为验证辅助喷嘴结构的优化设计,通过引纬平稳性、能耗和最大流速进行综合分析。结果表明:锥角为6°的单孔辅助喷嘴综合性能最优,最大流速和引纬平稳性分别提高了4.4%和36.7%;长宽比为3.3左右的矩形孔辅助喷嘴综合性能最优,引纬平稳性提高了7.3%;双孔辅助喷嘴根据上述3种指标获得对应指标下的最优组合以满足实际引纬的不同要求。

喷气织机主喷嘴气流性能的测试与分析

在SX 1型喷气织机测试仪上 ,对常用的几种主喷嘴进行了淹没射流测试 ,揭示了主喷嘴射流压力衰减率与射流距离及喷嘴芯内径的关系 ,认为调节主喷嘴喷嘴芯的转角对主喷气流的压力、风速及对纬纱的牵引力影响不大 ,主喷嘴气流压力衰减率存在一个峰值 ,要慎重选择喷嘴芯的内径。

基于Fluent的喷气织机主喷嘴纬纱牵引力分析与计算

针对实验方法无法获得导纱管内部各处纬纱牵引力的问题,为牵引力的理论分析与数值计算提供一种方法上的实现,将基于Fluent的主喷嘴流场数值模拟结果与相关文献的实验数值比较,得出了利用Fluent软件进行流场模拟的可行性。借助得到的主喷嘴导纱管内部流场的压力、速度及马赫曲线,可以得到主喷嘴导纱管内各处的纬纱牵引力。计算结果表明:纬纱在导纱管内所受牵引力随距离的增加而增大,在导纱管出口附近达到最大值;供气压力为0.2～0.4 MPa时,每增加0.1 MPa,纬纱总牵引力增加近1倍。