利用水射流技术对煤粉进行超细粉碎

分析了自激振荡水射流超细粉碎系统对煤粉颗粒的粉碎机理 ,讨论了影响粉碎效率的几种因素。试验结果表明 ,应用高压水射流技术对煤粉颗粒进行超细粉碎具有较好的应用前景。     

高压水射流粉碎原盐

高压水射流粉碎技术是近年发展起来的一项新型粉碎技术。文中介绍了水射流粉碎机理和新研制的后混合靶式水射流粉碎装置 ,并通过原盐粉碎实验证明 ,水射流粉碎具有效率高、工艺简单、产品粒度可调等特点 ,是一项具有良好发展前景的粉碎技术。     

新型高压水射流原盐粉碎设备研制

为提高高压水射流原盐粉碎设备的生产能力,降低能耗,通过采取改进物料混合喷嘴、改进加料和射流工作方式等措施,改进了单射流——物料侧进式高压水射流原盐粉碎设备的结构,设计开发出多射流——物料中进式高压水射流原盐粉碎设备。实验结果表明,多射流——物料中进式高压水射流原盐粉碎设备生产能力达到7.50t/h,产率为54.63%,比能耗降低到4.22kW.h/t,泵电机的效率达到93%。多射流——物料中进式高压水射流粉碎设备的研制成功为原盐水力粉碎新技术的工业化奠定了基础。     

利用热力辅助高压水射流进行超细粉碎的探讨

本文详细地介绍了热力和高压水射流技术在粉碎中的应用,说明了热力粉碎可以实现对物料的破碎或预损伤,高压水射流用于粉碎可实现高效、低耗、无污染。研究了将热力与高压水射流相结合进行矿物超细粉碎的可行性及其具体实现方法。     

高速水射流粉碎中射流冲击区水垫的增阻效应

为了解高速水射流冲击区特性和对物料粉碎效果的影响,通过理论分析、数值计算方法和采用自主研制的后混式高压水射流粉碎装置进行粉碎实验(以煤为粉碎物料),针对水射流在冲击区产生的水垫及其对物料粉碎的影响进行了研究。结果表明:高速水射流在靶体冲击区范围内存在水垫,水垫范围约为10倍喷嘴半径r0;射流冲击区水垫对粉碎不利,在有水垫增阻情况下,水垫对粉碎效率具有一定影响,特别是对低粒级产品减产影响明显;无水垫增阻情况下,物料粉碎较前者更加高效,产率也更高;研究水射流冲击区水垫增阻减产机理,对高速水射流粉碎技术及设备研究实践具有一定理论和设计参考价值。     

复杂光机系统机械结构件表面高压水射流量化清洗工艺研究

基于高压水射流喷淋清洗工艺,理论分析了不同高压水射流喷淋清洗工艺条件下机械结构件表面颗粒污染状态,给出表征颗粒污染物定量去除的数学表达式,并理论计算了高压水射流喷淋参数对机械结构件表面颗粒污染移除率的影响规律。结果表明:高压水射流喷淋流量、压强和喷淋面积对颗粒污染物的移除效率影响较大,并通过实验验证了不同高压喷淋清洗工艺对光机模块表面洁净度影响的数学表达式。经过验证,理论结果与实验结果符合较好。     

单进口后混式射流粉碎中多相流混合机理及加速特性

为了深入了解后混式高速水射流超细粉碎技术,以4种加速管管径条件下的液、气、固三相混合射流为对象,利用数值计算和粉碎实验相结合的方法,研究了多相混合射流相间的混合机理和加速特性,探讨了颗粒在加速空间中的分布规律。结果表明:水射流紊动掺气和卷吸作用是混合附加相的内在机理;混合射流对颗粒的加速存在分区,越靠近势流区冲击能量越大,优化喷嘴直径与加速管管径配置,迫使颗粒靠近或进入该区域可有效提高粉碎产率。颗粒在加速管内的空间分布为外层、内层高效加速区内含量最高,越靠近势流区颗粒含量越少,气流区内颗粒含量随加速管管径增大而增大。颗粒很难进入理想加速区,大部分仍依靠内、外层高效加速区加速。在保持自由射流流动形态的情况下,粉碎产率随加速管管径增大而下降,小管径对水射流能量和颗粒运动空间均具有更好的约束集中作用。     

高压水射流清洗机射流打击力的研究分析

水射流打击力是影响高压水射流清洗机清洗效果的重要因素之一,在一定程度上决定了高压水射流清洗机的清洗质量.本文主要从理论上对高压水射流清洗机的射流打击力进行了分析.     

高压水射流流动过程中能量损失的分析

通过对影响高压水射流打击力的各种因素的分析,使人们更好地认识喷嘴直径、胶管直径与清洗机压力、流量相匹配的重要性,从而更有效地使用高压水射流清洗机。理论证明,如果喷嘴直径、胶管直径与清洗机压力、流量不相匹配,会增大水射流在传输过程中的能量损失,降低水射流的打击力。     

工业管道的高压水射流清洗

着重介绍工业管道的高压水射流清洗的主要参数及部分工业管道的清洗实例，藉以说明高压水射流清洗是我国工业清洗的重要组成部分．     

A novel process for preparation of ultra-clean micronized coal by high pressure water jet comminution technique

A novel process for the preparation of ultra-clean micronized coal is presented in this paper. High pressure water jet mill replacing the ball mill is employed for coal comminution in the new preparation process, which is the essential difference from the traditional one. To compare the new preparation process with the traditional one, the comparison experiments were performed, with froth flotation tests of the fine particles ground by both mills using 0# diesel oil and n-dodecane as collector, 2-octanol as frother, and sink–float separation tests using mixtures of carbon tetrachloride–benzene and carbon tetrachloride–bromoform as dense liquid. Different parameters including combustible recovery, ash content of the clean coal, separation efficiency, and energy consumption were investigated based on the two different preparation processes. The results show that the new preparation process has high combustible recovery, low ash content of the product, high separation efficiency, and low energy consumption compared with the traditional one.The comminution mechanism of high pressure water jet mill is introduced in this paper. The high pressure water jet comminution technique has great potential in coal pulverization, having the advantages of low energy consumption, low iron content, and low equipment wear.     

Effective comminution of diatomaceous earth in a vertical type jet mill

Comminution characteristics of diatomaceous earth have been investigated in a vertical type jet mill of pilot plant scale; the diameter of the chamber of mill is 26.3 cm. Fluidization of the particles in the chamber has been proposed to enhance the comminution efficiency of the jet mill by promoting the effective contacting of powders with compressed air as well as the chamber wall. Effects of the pressures or densities of pulverizing-air and fluidizing-air and comminution time on the mean size of the particles and the rate of comminution have been examined. The statistical analysis of pressure fluctuations in the chamber of the mill has been utilized to predict the characteristics of the vertical-type jet mill taking advantage of the fluidization technique. The particle size and comminution rate have been correlated with the operating variables, respectively.     

水力喷射空气旋流器中射流雾化过程模拟及其机理

水力喷射空气旋流器(WSA)是一种新型高效的气液传质反应设备。采用雷诺应力模型和VOF两相流模型较好地模拟了WSA的气相压降特性、液相回流比和射流雾化过程,并讨论分析了雾化过程的机理。模拟和实验研究表明,WSA的气相压降随着进口气速的增加先后出现低压降区、压降突跳区、压降过渡区和高压降区4个特征区域,并给出了不同压降区域之间转折点气速的计算方法。射流在这4个压降区域里,分别表现为稳态射流、变形与袋式破碎、袋式破碎与剪切雾化和剪切雾化与离心分离等流态。射流在压降过渡区与高压降区的转折点左右实现充分雾化并达到最大相间传质面积。研究结果为建立基于WSA压降特性的射流雾化与流场调控方法提供了理论依据。     

水射流解离煤的分形特征

利用高压水射流粉碎机与球磨机对煤进行超细解离,对解离后的煤颗粒进行了扫锚电镜分析,利用扫锚电镜图像。基于图像处理技术与分形理论,计算了粒度分布分形维数、边界形状分形维数与节理表面分形维数。利用上述3种分维数对解离后的煤颗粒的分形特征进行了研究。     

Effect of Stress on Water Diffusion in Silica Glass

The diffusion of water in silica glass was measured as a function of applied uniaxial stress and hydrostatic pressure at selected temperatures. It was found that the diffusion coefficient of water increased exponentially with increasing tensile stress and decreased with increasing compressive stress and increasing hydrostatic pressure. The activation volume for water diffusion in silica glass was found to be ∼170 cm³/mol at 192°C and ∼72 cm³/mol at 350°C. The solubility of water in glass showed a trend opposite to the diffusion coefficient, namely, it decreased exponentially with increasing tensile stress and increased with increasing compressive stress and hydrostatic pressure. These stress (or pressure) dependences were attributed to the shift of the glass-water reaction equilibrium.     

Wet comminution of raw salt using high-pressure fluid jet technology

Based on the impact mechanism and fluid wedge effect of the high-pressure fluid jet, a new approach to raw salt comminution has been worked out. The fluid jet comminution process has a unique characteristic of providing a fine appearance for the product particle as well as a high washing efficiency. Dissolution of raw salt and loss of product are avoided owing to saturated sodium chloride solution used as high-pressure medium. Compared with mechanical comminution, the product processed by this technique has higher quality and better appearance. The working condition is also improved since the comminution is operated under wet conditions. Also, this approach has the potential to be used to comminute the thermally sensitive, inflammable and explosive materials.     

高压水射流清洗技术的应用

概述了高压水射流清洗的原理特点、装置的构造,同时介绍了高压水射流中射流压力、速度和流量等参数之间的关系,还有实际工作压力、喷射距离和入射角度的确定及高压水射流清洗技术的一些应用实例等.     

高压水射流清洗及喷砂设备的研究分析

高压水射流技术作为近30年来发展起来的一门新技术，因其高效、节能、无污染等优点，在各行业得到了广泛的应用。文章结合具体项目，首先阐述了高压水射流技术的原理及相关参数，然后介绍了高压水射流系统的组成，最后对系统的设计进行了详细说明。