重防腐涂料无气喷漆法的若干技术关键

无气喷漆法具有涂装效率高、涂层质量好、有利于环境保护等优点。阐述了无气喷漆机使用技术关键:机械类型、喷嘴的选择、喷漆压力的确定等。强调了无气喷漆时涂装作业的要点。     

无气喷漆机在钢结构涂装上的应用(一)

无气喷漆应用于钢结构件涂装是保证喷涂效率和膜厚质量的有效措施。介绍了无气喷漆机的工作原理、结构组成以及工艺参数,分析了无气喷涂的工艺特点,论述了喷嘴的选择方法以及不同公司喷嘴型号所表示的含义。     

喷漆室在涂装生产线中的合理选用

对比了各种喷漆室的性能;对喷漆室漆雾处理效率进行了分析,最终确定在涂装生产线中如何选择喷漆室的类型,从而保证喷漆效果和工件表面质量。     

汽车厂涂装喷漆循环水处理技术的应用现状及发展趋势

喷漆循环水作为汽车制造厂的重要环境影响因素,循环水系统的设备建造及水处理剂的选择对汽车厂的环境管理、三废排放具有极大的影响。作者介绍了汽车厂喷漆循环水处理技术的应用现状、发展趋势以及喷漆循环水处理设备构造的基本原理及影响因素,总结了目前在喷漆循环水处理中所用水处理剂的特点、性能及管理方法,展望了喷漆循环水处理技术的研究方向和发展趋势。     

真空干燥技术在香皂行业中的应用

本文报道了香皂生产中,根据皂胶温度、喷漆、喷出方式、喷嘴轴转数等诸影响皂基干燥因素,自行设计一条真空干燥生产线,与老式烘房干燥工艺相比成本可下降21.3元/t,蒸汽消耗指标下降5．8倍,     

选用、设计喷漆室及相关设备的经验谈（I）

从工业涂装用喷漆室的功能、分类、喷漆室系统设备及其组成、设计参数及其选择,以及设计使用中的注意事项等方面介绍了近20年中作者选用、设计和研究喷漆室及相关设备的经验.     

建筑物石质墙面喷漆广告去除剂的研制

本文依分子极性相同的物质易相溶原理,选择了去除建筑物墙面喷漆广告合理的溶剂,研究了溶剂种类、溶剂浓度、处理温度等对建筑物墙面喷漆广告去除的影响,找出了合理的工艺技术条件。试验结果表明,对单一溶剂来说,去除喷漆广告速度最快的为酯类,其次为酮类;而对复合溶剂而言,则是酯类和酮类的混合物去除喷漆广告速度最快,其中α-酯与环己酮复合剂(体积比为1∶1)为最好,反应时间仅为1min。温度升高时,喷漆广告去除所用的时间明显减少,考虑各方面的因素,处理温度选择在30~35℃为宜。     

水帘喷漆室空气洁净度与空气过滤器的应用研究

结合作者的实践经验,研究了空气洁净度标准以及水帘喷漆室内的空气洁净度要求,分析了空气过滤器的选择与使用维护的注意事项,论述了送风风机的选型以及水帘喷漆室使用维护的其它问题。     

旅客列车喷烘一体漆房设计方案探讨

对旅客列车喷烘一体化漆房中喷漆、烘干的工作原理,热功率的计算,送、排风方式的选择,以及喷漆设备与喷涂工艺等方案的设计进行了分析和探讨。     

浅析喷塑与喷漆的工艺特点

较详细地介绍了喷塑与喷漆二者的工艺特点,从技术可行性和经济合理性两方面提供参考依据,以正确选择喷塑或喷漆工艺,获得优异的涂膜质量且具有较低的涂装成本.     

引射喷嘴流量系数的计算方法

引　言引射雾化喷嘴是在螺旋导水芯雾化喷嘴基础上发展起来的一种新型的二次雾化型喷嘴 .由于它雾化效果好 ,目前被广泛应用于煤炭、冶金、化工行业 .引射喷嘴的结构如图 1所示 ,它是由带引射风罩的喷嘴外壳与双头 (三头 )螺旋导水芯组成 .导水芯有直通孔 ,当压力水通过导水芯时 ,形成三股(四股 )水流 .其中两股 (三股 )沿螺旋沟槽螺旋前进 ,另一股沿中心直线前进 ,三股 (四股 )水在喷嘴出口处汇合 .在出口处形成实心圆锥形水雾 ,这是水的第一次雾化 .当水雾以一定锥角经过喷嘴引射罩时 ,形成密封区 ,水雾将喷嘴出口后的空气带走 ,形成负压 …     

注射过程喷嘴内物料温度和压力的模拟与分析

利用Fluent软件对注射过程中物料在喷嘴内的流动进行了模拟,分析了喷嘴内剪切热产生的位置及喷嘴尺寸与物料温度变化和压力降的关系。结果表明,注射过程中喷嘴内最高温升位置出现在壁面附近的很小区域内,温升变化率随喷嘴圆管直径的增加而降低,随喷嘴圆管长度的增加而提高;喷嘴出口处物料温度随喷嘴圆管直径增加逐渐趋向均匀;注射过程中喷嘴内压力降随喷嘴圆管直径减少和长度的增加而提高。     

EFFECT OF CROSS FLOW ON THE SPRAY CHARACTERISTICS OF AN INDUSTRIAL FEED NOZZLE

The spray characteristics of a scaled-down version of an industrial feed nozzle are studied in the presence of a cross flow. Aerated liquid nitrogen is injected through the nozzle to generate the spray. The aeration rate is low and held constant, while two different liquid flow rates are used to produce the spray. A nonuniform wind profile is chosen to represent the cross flow condition. The droplet diameter and velocity measurements are acquired using a phase-Doppler particle analyzer. The results of the present study indicate that the spray momentum flux determines the extent of the jet bending. The droplets are accelerated significantly in the initial jet region as a result of flashing. However, further downstream of the nozzle, the vaporization of the droplets is considered to be negligible. The size-velocity correlation changes significantly for the case where the spray is shifted due to the cross flow.     

FLUID SHEET THICKNESS AND VELOCITY AT THE TIP OF A BLACK LIQUOR SPLASHPLATE NOZZLE

The fluid sheet thickness and velocity at the tip of a spray nozzle have previously been identified as being important to the ultimate droplet size distribution. In this investigation both the fluid sheet thickness and the velocity of the top surface just beyond the rim of a splashplate nozzle have been measured as functions of nozzle exit velocity and fluid viscosity. Measurements were made on two Babcock & Wilcox Co. splashplate nozzles, a 12-49 and a 15-52, specifically designed for black liquor, a by-product of wood pulping. Comparisons of the ratio of the sheet velocity to the nozzle velocity are shown to be very similar to previous data for the ratio of droplet velocity to nozzle velocity. Likewise, the dependence of the sheet thickness on nozzle exit velocity closely matches the previously measured dependence of the ultimate median droplet size on nozzle exit velocity. Both of these results are consistent with current theories of droplet formation mechanisms. Analysis of continuity and viscous drag on the splashplate are used to develop correlation equations for the data     

THE LABOR AND AIR-POWER COST OF SAND-BLASTING1

Efficiency data are given from experience on adjustment of air and sand quantities, size and shape of nozzle, and distance of nozzle from the work. Production data are given on blasting of large ware and barrel cleaning of small ware. The data are shown in curves.     

A SIMPLE DERIVATION OF THE CUTPOINT OF AN IMPACTOR

Impactors are designed according to numerical computations, which have been shown to give accurate predictions for the 50% cutpoint. However, such computer calculations obscure the basic physics of the impactor. Textbook derivations commonly assume circular streamlines and do not yield accurate results for the cutpoint. In this paper, a simple but accurate derivation is given for the cutpoint of an impactor with a rectangular nozzle, based on only very general assumptions as to the flow. For an impactor with a circular nozzle, the derivation requires an additional input datum and is less accurate. The derivation makes clear the essential physics of the impactor.     

EFFECT OF THE DROPLET AGGLOMERATION ON THE DESIGN OF SPRAY DRYER TOWERS

The agglomeration of water droplets along the distance from the atomising nozzle was determind experimentally. The effect of the droplet agglomeration upon the required height of the spray dryer is computed for different nozzle sizes and different gas temperatures.     

超细碳酸钙颗粒的离心分级

用一种工业型的牒式离心机对粒度小于8 μm的超细碳酸钙颗粒进行湿法分级.采用统计方法研究了与该离心机相关的主要工艺参数,如:离心力强度、牒类型、喷嘴尺寸、分流率和给料速率等.结果表明:这种牒式离心机可以有效地分级质量分数达到40%的微米粒级的物料,并可获得较窄颗粒粒度分布的超微细产品.离心分级效果与所用的主要参数呈经验关系.     

EFFECT OF THE DROPLET AGGLOMERATION ON THE DESIGN OF SPRAY DRYER TOWERS

ABSTRACT

The agglomeration of water droplets along the distance from the atomising nozzle was determind experimentally. The effect of the droplet agglomeration upon the required height of the spray dryer is computed for different nozzle sizes and different gas temperatures.     

A SCACE-UP STUDY OF NOZZLE TOWER SPRAY DRYERS

A quasi-one dimensional model taking into account hindered drying beyond the critical tmisture content and droplet size distribution is used to scale-up nozzle tower type of a spray dryer with uniformly distributed air entry, based on pilot plant data. A pilot plant with 8 m high and 1.7 m diameter spray dryer is used to collect the drying data. Equilibrium and critical mistwe contents of the particles are also experimentally msured. The index of drying rate in the hindered drying period is calculated frun the pilot plant data. This index is used in the M e 1 to determine the drying capacity and thereby the mixinnnn particle size that can be produced ina 3.5 m dimoeter 12 m high nozzle t- type of spray dryer. Experiments are carried out in this spray dryer to verify the calculated values of the spray drying capacity. It is s h m that the model when used along with the pilot plant data is adequate for scale-up calaculations for nozzle taer type of spray dryers.