Design of Laminar Operating Rotary Atomizers under Consideration of the Detachment Geometry

Abstract

In order to produce droplets with a narrow droplet size distribution, a new spraying system has been developed, i.e., a rotary atomizer with a multitude of comparatively large holes (LAMROT) through which the liquid flow is laminar. With this concept, it was possible to combine the advantages of capillary showers with the demand of plug insensitive operation and the aim of high throughput. The atomizer is designed as a multiple-hole cylinder. In this apparatus the liquid flows through the holes as in an open channel flow. At the hole exit, it changes into free jets which disintegrate according to the Rayleigh type giving rise to nearly monodisperse droplets. The main features of the construction are discussed. Along with calculation and determination of the hole geometry, possibilities for even distribution of the liquid in the atomizer for the required laminar conditions are shown. Furthermore, the latest results on the design of the detachment edges at the hole exits will be presented. Due to unfavorable flow conditions, it was necessary to fit tubes into the holes in the first prototype. This led to a complex and expensive construction and consequently caused further development.