Modelling the Sublimation-Desublimation Processes for Production of Ultrafine Powders

ثبت نشده
چکیده

The purpose of this work is to establish the theoretical foundations for calculating and designing the sublimationcondensation processes in chemical apparatuses which are intended for production of ultrafine powders of crystalline and amorphous materials with controlled fractional composition. Theoretic analysis of the primary processes of nucleation and growth kinetics of the clusters according to the degree of super-saturation and the homogeneous or heterogeneous nature of nucleation has been carried out. The engineering design procedures of desublimation processes have been offered and tested for modification of the Claus process. Keywords—Desublimation, controlled fraction composition, nucleation, ultrafine powders.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Thermal plasma synthesis of SiC from rice hull (husk)

Recently the synthesis of ultrafine powders has drawn considerable attention because these powders can have physical and chemical properties superior to those of bulk specimens. In particular, emphasis is on the preparation of ultrafine ceramic powders for their applications in the development of sintered products having higher density and lower sintering temperature. One such industrially impo...

متن کامل

Abnormal gas-liquid-solid phase transition behaviour of water observed with in situ environmental SEM

Gas-liquid-solid phase transition behaviour of water is studied with environmental scanning electron microscopy for the first time. Abnormal phenomena are observed. At a fixed pressure of 450 Pa, with the temperature set to -7 °C, direct desublimation happens, and ice grows continuously along the substrate surface. At 550 Pa, although ice is the stable phase according to the phase diagram, meta...

متن کامل

Aerosol production and crystallization of titanium dioxide from metal alkoxide droplets

In this experimental study, aerosol methods for producing titanium dioxide powders and increasing our knowledge of particle and crystal formation have been developed. Powders and ultrafine particles of titanium oxide were produced by an aerosol droplet decomposition route in tubular laminar flow reactors in air and nitrogen atmospheres. Reactor temperatures up to 1500°C were used with residence...

متن کامل

Measurement and Modeling of Acridine Solubility in Supercritical Carbon Dioxide

Supercritical carbon dioxide has gained increasing attention in food and pharmaceutical processing owing to the fact that it is environmentally inexpensive, not flammable, essentially non-toxic, and it has a convenient critical point. Also, it has been attracting much attention in many fields, such as extraction of sensitive materials and pharmaceutical processing and polymerization processes. ...

متن کامل

Effect of milling time on the crystallite size and microstructure of Al2O3/Mo Nano composite

In this paper, the production of Al2O3-Mo nano-composites via mechanical milling was investigated. Molybdenum and alumina powders with certain ratios were grounded in a planetary ball mill at different times. XRD technique was used to determine the crystallite size of the milled powders. The microstructure of milled powders was studied using optical and electron microscopes. The crystallite siz...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2013