Centrifugal Nozzles Research Articles

Preparation of iron powder by the thermal decomposition of iron pentacarbonyl

1. A new method is proposed for the preparation of electronic iron powders by the thermal decomposition of liquid iron pentacarbonyl atomized by means of centrifugal nozzles. 2. A technological process has been developed for the production of powders by the new method. Powder has been produced in the form of two fractions—a fine one from the filter (20%) and a coarser one from the decomposition apparatus (80%). The fine fraction consists mainly of particles 0.5–1.0 μ in size. 3. The electromagnetic parameters of both fractions meet present-day electronic industry requirements.

The Application of Cyclone Theories to Centrifugal Spray Nozzles

The problem of designing centrifugal spray nozzles has been attacked by applying well-established cyclone formulae; these provide a theoretical explanation for empirical relationships (which have been obtained previously‡) between nozzle output, spray cone angle, and pressure drop. The nozzle is designed by first selecting suitable values of the following quantities:— [Formula: see text] Both the above quantities should be greater than 1 in order that the subsequent prediction of design data may be as accurate as possible. Apart from this limitation, the values assigned to those quantities are largely arbitrary in that they are not dependent upon the final spray characteristics required, but, as they affect the dimensions of the nozzle, the original selection may have to be adjusted after preliminary calculations if the estimated nozzle shape is in any way unsuitable. They may also have to be adjusted if they result in the calculated value of the quantity t/RE, i.e. (orifice film thickness)/(exit radius), being much greater than 00·5, as this will involve loss of accuracy in applying the theoretical equations. Having finally selected suitable values of Φ and Ri/ Re, the dimensions of the nozzle can be calculated by substituting the required values of the spray characteristics in the various formulae.