PROCESSES AND EQUIPMENT OF CHEMICAL INDUSTRY Effect of Stirring Devices on the Intensification of Gas Fluid Processes

A comparative analysis is made of the operation of apparatus of rotary-pulsation and ejector types with self-suction turbine agitator. The dependence of the efficiency of operation on the output capacity and energy-related characteristics determining power consumption for agitation of gas fluid mixtures were determined experimentally. One of the main parameters characterizing the effi- ciency of a gas fluid apparatus is the phase surface contact area. Present attempts to raise its value are commonly associated with reducing the geometric dimensions of gas bubbles by using, as a rule, various bubbling and mechanical stirring devices (1 3). How- ever, gas fluid apparatus presently used in chemical and other industries have a number of serious disad- vantages and frequently fail to satisfy modern require- ments to the output capacity, quality, and energy ex- penditure per unit product. Therefore, development of new absorber designs and improvement of the exist- ing types of apparatus are, beyond any doubt, urgent tasks. One of possible ways to solve this problem is to provide intensive stirring ensuring a significant rise in the phase boundary area and concentration of a considerable amount of energy in small volumes. It is known that the use of low-frequency (20 20 000 Hz) acoustic elastic vibrations allows in most cases a sub- stantial intensification of the homogenization process. In this case, such phenomena as cavitation, acoustic pressure, and pulsing microflows occur in the medium being treated, making higher the rate of physicochem- ical processes in heterogeneous systems (3). Acoustic vibrations are generated by means of hy- drodynamic transmitters. In transmitters of this kind, acoustic vibrations are generated by rotary-pulsation devices. In view of their great potentiality, it may be assumed that that use of gas fluid rotary-pulsation apparatus (RPA) for performing absorption will allow a substantial intensification of this process. The goal of this study was to analyze the efficiency of conventional gas fluid apparatus (of ejector type and with turbine agitator) and RPA for performing nitrosation of diphenylamine (DPA) in an organic solvent (trichloroethylene, TCE, fluid phase) with a mixture of nitrose gases, NO and NO 2 (gas phase), with the aim to develop a multifunction apparatus for intensifying processes of absorption, homogenization, and dispersion.