Metal Powder Production by Vapor Explosion

蒸气爆炸法生产金属粉末

基本信息

批准号：
09450094
负责人：
ITO Takehiro
金额：
$ 9.09万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450094/
关键词：
Vapor explosion Water atomization process Phase change Metal powder Fragmentation Zinc oxide

项目摘要

Thermal interaction between molten metal drop and water has been investigated experimentally. The purpose of this study is to disclose the mechanisms of fragmentation and rapid cooling in steel-powder-making process, so-called water atomization process. Experimental apparatus consists of heating unit, water injection system and powder-collection part. Mainly, induction heating is used to melt the metals. Temperatures of the molten metal are measured by the radiation thermometer.First, The second, water atomization experiments have been performed using a molten iron drop. Two types of water nozzle were used. One is straight nozzle and the other is flat nozzle. Four nozzles of each type were mounted on the experimental unit with some injection angle. The direction of four nozzles is focused to the stream center, to which the molten metal is dropped. Influence of water temperature, type and angle of nozzles on the shape, the size distribution and the yield rate of powders were investigated.The quartz glass nozzles for molten iron were used to control the dropping position with higher certainty. The exit diameters of the nozzles are 1.5, 2.5, 3.5 and 5.5 mmφ. The use of these nozzles brought us good yield rate and the size of produced powders ranges mainly below 100μm.As a new attempt, we tried to develop a zinc oxide power production process. In the conventional process, auxiliary heat is needed to vaporize zinc metal. By the thermodynamic consideration, it is possible to realize a spontaneous oxidizing process by recovering heat of reaction. We have made a preliminary experiment of zinc oxide production. Duration of spontaneous reaction was 15min in the condition of air flow rate of 10L/min, argon flow rate of 5L/min and heat input of 1100W. By microscopic observation, the size of power produced in the present study is larger than that of commercially available power. The recovery of heat is estimated to be 280W.

熔融金属滴和水之间的热相互作用已通过实验研究。这项研究的目的是披露钢粉制造过程中碎片化和快速冷却的机制，所谓的水雾化过程。实验设备由加热单元，注水系统和粉末收集部分组成。主要是，诱导加热用于融化金属。熔融金属的温度是通过辐射温度计测量的。首先，使用熔融铁滴进行了水雾化实验。使用了两种类型的水喷嘴。一个是直发喷嘴，另一个是平面喷嘴。每种类型的四个喷嘴都以一定的注入角度安装在实验单元上。四个喷嘴的方向集中在熔融金属被掉落到的溪流中心上。研究了水温，喷嘴的类型和角度对形状，尺寸分布和粉末的产量率的影响。使用熔融铁的石英玻璃喷嘴以更高的确定性来控制掉落位置。喷嘴的出口直径为1.5、2.5、3.5和5.5mmφ。这些喷嘴的使用为我们带来了良好的收益率和产生的粉末范围，主要低于100μm。随着新的尝试，我们试图开发氧化锌的发电过程。在常规过程中，需要辅助热使锌金属蒸发。通过热力学的考虑，可以通过恢复反应热来实现赞助商的自发氧化过程。我们已经进行了氧化锌生产的初步实验。发起人自发反应的持续时间为15分钟，空气流速为10L/min，氩气流速为5L/min，热输入为1100W。通过显微镜观察，本研究中产生的功率大小大于市售功率的功率。估计热量的回收率为280W。