Fine metal powder atomizing spray nozzle with molten metal easily flowing out

Abstract

The invention discloses a fine metal powder atomizing spray nozzle with molten metal easily flowing out. The fine metal powder atomizing spray nozzle is formed by a first assembly and a second assembly, wherein the first assembly is formed by connecting a cone frustum with the lower part of a cylindrical table; a liquid guide pipe is arranged at the center of the first assembly; the second assembly is formed by connecting a conical inner cavity with the lower part of a cylindrical inner cavity; an annular groove is formed in the wall of the cylindrical inner cavity of the second assembly; a horizontal ring surface and an inner arc rotating body which are sequentially connected are arranged at the connected part of the cylindrical table and the cone frustum; a horizontal ring surface and an outer arc rotating body which are sequentially connected are arranged at the connected part of the cylindrical inner cavity and the conical inner cavity; the annular groove forms an air inlet cavity; a three-section type Laval gas channel is formed between the first assembly and the second assembly; the first section is a horizontal air inlet retraction section formed by the horizontal ring surfaces of the first assembly and the second assembly; the second section is an arc expansion section formed by the inner arc rotating body of the first assembly and the outer arc rotating body of the second assembly; and the third section is a linear expansion section formed by the cone frustum of the first assembly and the cylindrical inner cavity of the second assembly.

Description

technical field [0001] The invention relates to an atomizing nozzle which uses a supersonic airflow to atomize liquid metal into small liquid droplets and solidify into powder, in particular to a fine metal powder atomizing nozzle from which the metal liquid flows out easily. Background technique [0002] Gas atomization technology is used in the production of metal powder. The principle of powder making is the process of crushing liquid metal flow into small droplets and solidifying into powder with a high-speed airflow. Gas atomized powder has the advantages of high sphericity and controllable powder particle size. [0003] The atomizer is the core of the gas atomization powder making technology, and the atomizer determines the performance and atomization efficiency of the atomized powder. It is the development trend of the atomizer to improve the yield of fine powder (powder with a particle size of less than 45 μm) and the controllability of the powder, and to reduce the...

AI Technical Summary

Problems solved by technology

According to existing knowledge and experience, the length of the catheter has an important influence on the stability of the atomization process, especially for metals with high melting points. Too long catheters (such as more than 30mm) will affect the stability of the atomization. sex brings many problems

The liquid catheter of the atomizing nozzle used in general industry is not directly heated (direct heating is more complicated and has an impact on the nozzle), but relies on the radiation heating of the tundish. A long catheter will lead to insufficient radiation temperature and lead to The outlet temperature of the tube is not high, which is easy to cause plugging and flow interruption

The use of too long catheter for high melting point metals often makes it difficult for the melt to flow down, and the success rate of atomization is not high. In industrial practice, the diameter of the catheter is often increased (such as increased to 6mm or above) to solve this problem. a question

Although increasing the diameter can solve the problem of plugging and flow interruption, it will also significantly increase the flow rate of the molten metal and the size of the atomizer, which will lead to a significant decrease in the atomization efficiency and a significant coarsening of the powder particle size. Therefore, in the preparation In the case of powders with fine particle size, this method is not advisable

[0006] Analysis of existing patents shows that the use of Laval-shaped gas flow channels is a prerequisite for improving atomization efficiency. According to the relevant knowledge of gas dynamics, in order to obtain the highest air velocity, the ratio of the maximum to minimum cross-sectional area of ​​the expansion section of the Laval tube is 3 to 4, because the airflow of the atomization nozzle intersects the atomization point at a certain angle (generally less than 60°), in order to reduce the adverse effect of the turbulence of the airflow on the atomization area, the distance of the straight line is longer, generally If it reaches more than 20mm, the expansion section of the existing patent is linear, which will cause the total thickness of the nozzle to not be reduced, at least to reach more than 50mm, which will inevitably lead to the length of the catheter tube being greater than 50mm, which is not conducive to the stability of the atomization For the preparation of fine powder, a nozzle with a completely different structure is required, which not only has a Laval airflow channel, but also can significantly shorten the length of the catheter

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