Centrifugal Spray Research Articles

Microstructure and materials processing

The introduction of innovative processing to control and tailor the microstructure of materials to give the appropriate properties is increasingly important in producing new and improved products. Microstructure and processing is considered for a number of ‘advanced’ and conventional materials. The ‘advanced’ include rapid solidification processing of aluminium-transition metal alloys, centrifugal spray forming of alloys and metal-matrix composites, and hydrogen-decrepitation processing of rare-earth magnet materials. Developments in processing of conventional alloys are considered for surface engineering applications and austempering ductile cast iron.

Spray forming by centrifugal spray deposition (CSD): A.R.E. Singer, D.R.G. Davies (Sprayforming Developments, Swansea, UK)

Spray forming by centrifugal spray deposition (CSD): A.R.E. Singer, D.R.G. Davies (Sprayforming Developments, Swansea, UK)

Centrifugal spray forming of large-diameter tubes

Abstract The development of a new centrifugal spray forming process is outlined, from early laboratory work to the stage of industrial production. Particular attention is paid to the work at AERE Harwell, where 380 mm dia. tubes were produced in Nimonic 80A. The properties of the product are related to the atomizing and deposition variables, with respect to the structures produced and the concept of incremental solidification.

Method for the analytical calculation of the operating costs of centrifugal spray dryers

Method for the analytical calculation of the operating costs of centrifugal spray dryers

Effect of various spraying factors on the size distribution of drops

The results of an investigation into the fractional composition and mean size of a system of liquid drops with a wide range of particle size are presented. The drops are produced by means of a centrifugal disc spray.

Size distribution of droplets from centrifugal spray nozzles

AbstractMethods for expressing, measuring, and correlating drop‐size distribution data for centrifugal spray nozzles are discussed.A method for collecting spray droplets in liquid nitrogen is described which is rapid and efficient for most sprayed liquids which freeze above —20°C. Comprehensive correlations for drop‐size distributions are reported based on 114 runs performed with the liquid nitogen method.

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.

A Study of the Chemical of the Chemical and Physical Properties of Remade Milk

Summary A study of the physical and chemical properties of milk remade from three types of whole milk powder and reconstructed skim milk powder and butter led to the following results: Remade milk shows the freezing point of fresh milk when made with the proper proportions of powder and water. For the drum process powder this was found to be 10.6 per cent powder, for the centrifugal spray 12.8 per cent powder, for the pressure spray 12.5 per cent powder, and for the reconstructed milk, 9.16 per cent powder and 4.16 per cent butter. The specific gravity of the remade milks was found to lie within the limits of variation of fresh milk when made up in the proportions which give a normal freezing point. The viscosity of the remade milks was higher than normal. This was especially true of milk remade from the drum process powder. The specific electrical conductivity of each type of milk except the drum process was normal when the milks were made up in the proportions which gave a normal freezing point. The drum process milk exhibited a high conductivity which may have been due to the fact that this powder is made from partially skimmed milk. The milk made from the centrifugal spray powder was the only one which gave a normal cream layer on standing. The milk made from the centrifugal spray powder showed no deficiency of soluble proteins, but the soluble protein content of the other milks was less than normal. This was especially true of the milk made by the drum method. The drum process milk and the reconstructed milk failed to coagulate with rennet. The spray process milks showed a rennet coagulability and character of curd somewhat like that of pasteurized milk, the centrifugal spray milk being the nearest to the pasteurized milk in this regard. At a low concentration of added acid and alkali all the remade milks showed less buffer than normal milk in terms of pH. Peroxidase was absent from the drum process milk, but was strongly active for the other remade milks examined.