Atomization technology, or the fragmentation of a liquid stream into particles, is a key technology used in a wide range of cross-industry applications. The atomized spray is widely used in fuel injection for motorized vehicles, 3-D printing, electric power generation and thermal spray technologies. 19,500 U.S. companies, 94 percent of which are small and medium enterprises, manufacture or use atomized products, which represent $1.46 trillion in goods and employ more than 2.2 million people. Atomization can improve efficiency, quality and cost in a variety of manufacturing processes.
The present invention relates to a method and device for atomizing (nebulising) a liquid medicament formulation into an aerosol characterized by a small droplet size on average, a narrow and constant droplet size distribution and/or a low propagation rate. The droplet size distribution is facilitated by the preferred deflection and the impact of the jet 4 on the contact surface 5.
When fluid passes through a nozzle, its potential energy becomes kinetic energy. As the liquid leaves the nozzle, it forms an aerodynamic wave pattern that is determined by the geometry of the nozzle orifice and its design. The resulting atomization pattern is determined by the flow rate of the liquid through the orifice, the shape and diameter of the nozzle and its orifice, and the surface tension of the fluid.
Different methods are used for atomizing fluids in order to obtain a precise, high-quality, and controllable spray. For instance, centrifugal atomization, which is common for coating applications, involves a nozzle that introduces the liquid at the centre of a spinning disc or cup. The centrifugal force then carries the liquid to the edge of the disk, where it breaks up into ligaments that can be controlled by both the fluid flow rate and the disk speed.
Ultrasonic atomization is another atomization technology that has been developed and applied in various fields. It is based on the principle of using nickel electrode piezoelectric ceramics to produce ultrasonic waves, which are highly effective in acoustic nebulisation of liquids. The Atomization technology is simple and cost-effective, since only a single piezoelectric ceramic disc is required as the atomizer transducer. This makes it very popular in humidification devices such as ultrasonic vaporizers, as well as medical and industrial uses like atomizing metal powders for metallurgical processing and welding.
The research carried out by AP&C shows that ultrasonic atomizers are much more effective than conventional gas atomizers, especially in terms of particle size distribution and the breadth of the distribution. This is because the atomised metal powders generated by ultrasonic atomizers, as shown in Figure 6, have a more uniform distribution than those produced by gas atomizers and therefore have higher yields. In contrast, the atomised metal powders produced by gas atomizers are typically log-normally distributed, and as such, their yields can only be in the range of 80-98%. This is why the majority of manufacturers use gas atomizers for MIM processes such as HIP and VA, in which case clean powder surfaces are critical for high yields.
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