Development of Executive Equipment Design for Implementing the Process of Generating of Drops of Microand Nanoscale Range

Abstract

Modeling of velocities and temperatures processes distribution in the plasma-forming channel determining the design features and optimal parameters of the plasma torch nozzle is one of promising directions in development of plasma technologies. The aim of this work was to simulate the processes of velocities and temperature distribution in the plasma-forming channel and to determine the design features and optimal geometric parameters of the plasmatron nozzle which ensures the formation of necessary direction of plasma flows for generation of surface waves on the surface of a liquid metal droplet under the influence of the investigated instabilities.One of the main tasks is to consider the process of plasma jet formation and the flow of electric arc plasma. For obtaining small-sized particles one of the main parameters is the plasma flow velocity. It is necessary that the plasma outflow velocity be close to supersonic. An increase of the supersonic speed is possible due to design of the plasmatron nozzle especially the design feature and dimensions of the gas channel in which the plasma is formed. Also the modeling took into account dimensions of the plasma torch nozzle, i. e. the device should provide a supersonic plasma flow with the smallest possible geometric dimensions.As a result models of velocities and temperatures distribution in the plasma-forming channel at the minimum and maximum diameters of the channel were obtained. The design features and optimal geometric parameters of the plasmatron have been determined: the inlet diameter is 3 mm, the outlet diameter is 2 mm.The design of the executive equipment has been developed and designed which implements the investigated process of generating droplets of the micro- and nanoscale range. A plasmatron nozzle was manufactured which forms the necessary directions of plasma flows for the formation of surface waves on the metal droplet surface under the influence of instabilities. An algorithm has been developed for controlling of executive equipment that implements the process of generating drops of micro- and nanoscale range.

Determination of Optimal Modes for the Production of Micro Range Metal Powders

“…At a distance of more than 4 mm, the main arc does not ignite. This parameter was taken into account in the developed design of the plasmatron nozzle [31], in which this parameter is l -3 mm.…”

“…Optimum value of the distance from the wire to the Laval nozzle (L, mm) (Fig. 2) was found experimentally [31,34,35]. The dimensions of the resulting particles were chosen as optimization parameters.…”

“…In this case, the formation of powders is derived from individual particles heated and accelerated with a hightemperature gas jet -plasma. It is obtained in a special original plasma generator by blowing the plasma-forming inert gas into an electric arc resulting between two electrodes [31]. Based on this method, a laboratory setup was developed [31], which allows you to control the parameters of the process and, accordingly, the properties of the powders obtained.…”

“…It is obtained in a special original plasma generator by blowing the plasma-forming inert gas into an electric arc resulting between two electrodes [31]. Based on this method, a laboratory setup was developed [31], which allows you to control the parameters of the process and, accordingly, the properties of the powders obtained. This technology allows obtaining a wide range of powders of various metals and alloys.…”