Open Access

ARTICLE

Influence of Nozzle Orifice Shape on the Atomization Process of Si₃N₄ in a Dry Granulation Process

Dongling Yu¹, Huiling Zhang¹, Xu Zeng¹, Dahai Liao^1,*, Nanxing Wu^2,*

1 School of Mechanical and Electronic Engineering, Jingdezhen Ceramic Institute, Jingdezhen, 333403, China
2 National Engineering Research Center for Domestic & Building Ceramics, Jingdezhen, 333001, China

* Corresponding Authors: Dahai Liao. Email: ; Nanxing Wu. Email:

Fluid Dynamics & Materials Processing 2021, 17(3), 569-586. https://doi.org/10.32604/fdmp.2021.014711

Received 23 October 2020; Accepted 05 February 2021; Issue published 29 April 2021

Abstract

In order to reveal the intrinsic fluid-dynamic mechanisms of a pressure-swirl nozzle used for Si₃N₄ dry granulation, and effectively predict its external spray characteristics, the dynamics of air-atomized liquid two-phase flow is analyzed using a VOF (Volume of Fraction) method together with the modified realizable k-ε turbulence model. The influence of nozzle orifice shape on velocity distribution, pressure distribution is studied. The results show that the pressure difference in a convergent conical nozzle is the largest with a hollow air core being formed in the nozzle. The corresponding velocity of atomized liquid at nozzle orifice is the largest. Using a self-designed atomization experiment platform, the velocity and pressure of atomized liquid and the spray cone angle are measured for three nozzles with different orifice shapes. The micro-morphology of Si₃N₄ particles is also determined. These data confirm the correctness of numerical simulation. Considering atomization performance of the nozzle, the contraction conical nozzle is more suitable for the atomization of Si₃N₄ in practical production based on the dry granulation approach.

---

Keywords

---