Theory of pressure swirl atomisation and study on the characteristic of droplet size in atomisation

Abstract

Based on the observation of the working condition in pressure swirl atomisation experiments, this article tries to suggest a model of the mechanism of pressure swirl atomisation—the atomisation theory of pressure swirl spray of conical film. Under some basic assumptions, the formula for the characteristic of droplet size of pressure swirl atomisation is derived:

$$d_z = k_d \cdot \left[ {\frac{3}{{4\pi }} g \frac{\sigma }{\gamma } \cdot \frac{{\phi ^2 }}{{\eta _R^2 }} \cdot \frac{{d^2 _C }}{{\omega _{CT}^2 }} \cdot \cos ^2 \theta } \right]^{1/3} $$

((m))

The above theory agrees basically with the actual working conditions in atomisation, and gives the latter a compratively good interpretation.

In this article, theoretical calculations are worked out for the characteristic of atomised droplet size of some Oil atomising nozzles used in power plants in our country (the People's Republic of China) and are compared with actual test data. The results show that the theory is of some value to preactice, and it is recommended to those concerned for reference.