Features of Acoustic Emission Accompanying the Operation of Hydrodynamic Process Mechanical Activators in Constrained Conditions

Abstract

To assess the possibility of using the acoustic emission method in the direction of selecting activators of hydrodynamic processes of rotary apparatuses (machines) for processing liquid media in constrained conditions, experimental studies of hydrodynamic and acoustic effects accompanying two main modes of their application were carried out: the first is operation in the mode of activator frequency cyclic change, the second is operation in the mode of fixed activator rotation frequency. Seven forms of hydrodynamic activators of three types (vane, turbine and disk) and a rotary pulse apparatus applied for disinfection of lubricants were used in the research. Using conventional and high-speed video, the main hydrodynamic effects accompanying the operation of each type of activator were identified, which were compared with the established acoustic effects and measurements of temperature and the Reynolds centrifugal criterion. According to the results of the research, the possibility and limitations of using the acoustic emission method for comparing the effectiveness of activators and modes of liquid treatment in rotary pulse devices in conditions of its turbulent motion are shown. Under constrained operating conditions of activators imitated by the width of the working chamber, an acoustic emission peak never described in literature earlier was revealed, which differs from the noise accompanying the turbulent movement of the liquid. The relationship between the change in the amplitude of the peak of acoustic emission with the rate of change in the rotation of the activators and the rate of pumping the medium through the working chamber of the rotary pulse apparatus is also established. The results obtained can be used to select and compare the form of activators of hydrodynamic processes, as well as to select and maintain an effective mode of disinfection of aqueous solutions.