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.

通过实验研究了熔融金属滴与水之间的热相互作用，本研究的目的是揭示钢粉制造过程中的破碎和快速冷却的机制，即所谓的水雾化过程。注水系统和粉末收集部分主要采用感应加热来熔化金属，通过辐射温度计测量熔融金属的温度。第一，第二，使用水雾化实验。使用两种类型的水喷嘴，一种是直喷嘴，另一种是平喷嘴，在实验装置上安装有一定喷射角度的四个喷嘴。研究了铁水滴入的水温、喷嘴类型和角度对粉末形状、粒度分布和产率的影响。采用石英玻璃铁水喷嘴。喷嘴的出口直径有1.5、2.5、3.5和5.5mmφ，这些喷嘴的使用给我们带来了良好的成品率，生产的粉末尺寸主要在100μm以下。我们尝试开发一种氧化锌粉末生产工艺，在传统工艺中，需要辅助热量来汽化金属锌，通过热力学的考虑，可以实现氧化锌粉末的生产。在空气流量10L/min、氩气流量5L/min、热输入1100W的条件下，进行了自发反应生产氧化锌的初步实验。通过微观观察，本研究产生的功率大小比市售功率大，热量回收估计为280W。